Mobile mix plants for deployment at airtanker bases to provide fire retardant products

Abstract

Systems and methods for providing a ready-to-use (RTU) fire retardant product are disclosed. In an aspect, a mobile mix plant for deployment at an airtanker base to provide a ready-to-use (RTU) fire retardant product containing at least one fire retardant salt for loading onto an airtanker includes a liquid concentrate (LC) tank. The mobile mix plant further includes an automated proportional mixing valve that controls a mixture of LC and water to provide the RTU fire retardant product. The mobile mix plant includes at least one controller communicatively coupled to one or more sensors configured to monitor aspects of the mix plant operation, LC fire retardant, and RTU fire retardant product including storage and flow parameters.

Description

MOBILE MIX PLANTS FOR DEPLOYMENT AT AIRTANKER BASES TO PROVIDE FIRE RETARDANT PRODUCTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims a priority benefit to U.S. Provisional Patent Application No. 63 / 557, 180, filed February 23, 2024 and entitled “Mobile Mix Plants for Deployment at Airtanker Bases to Provide Fire Retardant Products,” which is incorporated herein by reference in its entirety.BACKGROUND

[0002] Long-term fire retardants contain retardant salts that decrease fire intensity and slow the advance of a forest fire. Such fire retardants conventionally are available as dry powders or liquid concentrates (LCs) that are mixed with water, wherein the resulting “ready-to-use” (RTU) mixture improves the effectiveness and ability of water to cling to fuels. The U.S. Department of Agriculture Forest Service Specification 5100-304d, attached hereto as APPENDIX 1, provides specifications of long-term fire retardants for wildland firefighting in the United States (these specifications also have been adopted in some other countries). Some examples of long-term fire retardants that have been qualified by the U.S. Department of Agriculture Forest Service as of September 2022 for wildland fire management in accordance with Forest Service Specification 5100-304d are listed in APPENDIX 2, which is incorporated herein by reference with respect to U.S. Provisional Patent Application No. 63 / 557,180.

[0003] As noted above, long-term fire retardants conventionally are prepared at centralized manufacturing facilities to form dry powders or liquid concentrates (LCs). These dry powders or LCs are then shipped to deployment areas, such as airtanker bases that support aerial fire management operations. At such bases, the dry powder or LC fire retardants are mixed with water to form a ready-to-use (RTU) fire retardant product, which is then loaded onto various types of aircraft that are deployed to drop the RTU product on or near fires. Examples of various aircraft employed to drop fire retardant on fires include a Single Engine Air Tanker (SEAT) with a retardant capacity of 800 gallons or less, a Large Air Tanker (LAT) with a retardant capacity of up to 8000 gallons (e.g., 2000-4000 gallons), and a Very Large Air Tanker (VLAT) with a retardant capacity of over 8000 gallons.

[0004] The U.S. National Wildfire Coordinating Group (NWCG) has published an interagency guide regarding the planning and setup of fire retardant air bases, which is incorporated herein by reference to U.S. Provisional Patent Application No. 63 / 557, 180, as APPENDIX 3 (Interagency Retardant Base Planning Guide February 2006). Standards for airtanker base operations as published by the National Wildfire Coordinating Group (NWCG) are incorporated herein by reference to U.S. Provisional Patent Application No. 63 / 557,180 as APPENDIX 4 (NWCG Standards for Airtanker Base Operations, PMS 508 June 2022).

[0005] At a given retardant airtanker base, a “mix master” is a qualified individual who mixes dry powders or LCs with water at specified ratios (e g., see APPENDIX 1 and APPENDIX 2) to prepare ready-to-use (RTU) fire retardant product to be loaded onto an airtanker. The mix masterworks in a retardant “mix plant” constructed in an airtanker loading area (or “pit”) at the airtanker base that includes various equipment to facilitate mixing of dry powders or LCs with water. FIG. I illustrates respective elements of a conventional LC mix plant at an airtanker base.[0006J As illustrated in FIG. 1, particularly with respect to liquid concentrate (LC) fire retardants, a conventional LC mix plant includes at least one tank containing the LC fire retardant. Some examples of conventional LC fire retardants that would be diluted and blended in the conventional LC mix plant shown in FIG. 1 include the PHOS-CHEK® LC95 series and LCE20-FX liquid concentrates, having viscosities in a range of from about 100 to 400 centipoise (cP).[0007J The conventional LC mix plant shown in FIG. 1 also includes a water tank and a manually- operated proportioning valve to blend the LC fire retardant with water according to specified mixratios and thereby create ready-to-use (RTU) fire retardant product (“mix”). The conventional LC mix plant also would include a gas-powered loading pump to load the RTU fire retardant product onto an airtanker, as well as various plumbing (e.g., four-inch diameter pipes or hoses) to interconnect the LC tank(s), water tank, manually-operated proportioning valve, and loading pump. As would be appreciated by one of ordinary skill in the art, a conventional LC mix plant of this type does not require any electrical power for operation.

[0008] As illustrated in FIG. 1, at the output of the loading pump, a flow meter is required to detect a flow rate (e.g., gallons / minute) and density (or specific gravity) of the RTU fire retardant product as it is being loaded onto the airtanker. As noted in APPENDIX 3 (Interagency Retardant Base Planning Guide February 2006, page 40), the U.S. Department of Agriculture Forest Service requires that a mass flow meter must be utilized for all aircraft loading applications “to ensure that safe aircraft load limits are not exceeded, to help optimize payloads, and to ensure that just compensation is paid to retardant contractors.” Mass flow meters must be installed in the loading lines in such a way that each plane load of RTU product is quantified and product density is monitored. As also noted in APPENDIX 3 (Interagency Retardant Base Planning Guide February 2006, page 35), a target retardant delivery rate for a Large Air Tanker (LAT) is 400 to 500 gallons per minute and for a Single Engine Air Tanker (SEAT) it is 200 to 300 gallons per minute. One example of a conventional flow meter includes a Micro-Motion* flow meter, which utilizes Coriolis flow tubes vibrating in opposition to one another when fluid is flowing through the tubes and a drive coil is energized to cause the tubes to oscillate. As would be appreciated by one of ordinary skill familiar with airtanker base operations, given the requirements specified in APPENDIX 3, the flow meter is typically the last component in the path of RTU fire retardant product flow prior to an airtanker’s supply tank.

[0009] Regarding quality control of the RTU fire retardant product, as also shown in FIG. I , a sampling valve located after the manually-operated proportioning valve and before the gas- powered loading pump is employed to permit sampling of a small amount of RTU product for analysis using a hand-held refractometer. Such a hand-held refractometer conventionally is used periodically at retardant airtanker bases to determine the amount of retardant salt in a sample of RTU fire retardant product. The concentration of retardant salt in the RTU product determines the density (mass per unit volume) of the RTU product, which in turn determines the refractive index(ability to bend light) of the RTU product - a refractometer is employed to measure this refractive index, which in turn is correlated to salt content and density. Knowing the density (or specific gravity) of the RTU product is important in determining the weight of an airtanker after it has been loaded with the RTU product. Examples of conventional hand-held refractometers used at airtanker bases are provided in APPENDIX 5, which is incorporated herein by reference to U.S. Provisional Patent Application No. 63 / 557, 180 (as “Refractometers for Evaluating Wildland Fire Retardants”).

[0010] Pursuant to section 4.3.2 of the U.S. Department of Agriculture Forest Service Specification 5100-304d (attached hereto as APPENDIX 1), “the refractometer reading of a properly mixed retardant shall be determined using a hand-held refractometer that the arbitrary scale found in industrial fluid testers or the Brix scale when needed” (as would be readily appreciated by those of skill in the art, the arbitrary scale found in industrial fluid testers is known as the 10440 VP arbitrary scale). Accordingly, as shown in FIG. 1, a mix master (or other authorized pit personnel at the retardant airtanker base) conventionally uses a hand-held refractometer to measure the refractive index of the RTU product, which as noted above correlates to the concentration of retardant salt in the RTU product. To this end, as noted in APPENDIX 5 (e.g., see pages 67-70), the mix master applies a small sample of RTU product to a prism of the refractometer and then holds the refractometer to a light source to take a reading. Such manual measurements of refractive index of the RTU product typically would be done once per each aircraft load.SUMMARY

[0011] The Inventors have recognized and appreciated that there are multiple shortcomings with conventional fire retardant mixing operations, particularly with respect to liquid concentrate (LC) fire retardants. First, mixing of LC fire retardants with water generally is a time-consuming process, which is a problem in firefighting where time is of the essence (e.g., it can take 20 minutes or more to adequately mix an LC with water to form the RTU product for application to a fire). Accordingly, the time it takes to dilute and mix LC fire retardant with water to make ready -to-use (RTU) fire retardant product may limit how quickly a forest fire can be quelled. Another problem with conventional LC mixing operations includes quality control and variability between batches (e.g., variations over time in concentration and / or homogeneity of the RTU product), which can adversely affect the ability to effectively control fires.

[0012] The Inventors have further recognized and appreciated that the foregoing and additional challenges arise if a relatively higher viscosity liquid concentrate (LC) fire retardant is used to prepare an RTU fire retardant product. The U.S. Department of Agriculture Forest Service Specification 5100-304d, attached hereto as APPENDIX 1, defines viscosity ranges for mixed RTU fire retardant products in Section 1.2.5 as follows:

[0013] Although the viscosity categorizations in the above chart are applied to mixed RTU fire retardant products, they may also be applied to LCs for purposes of comparison and illustration. In particular, the Inventors have considered the use of LCs having a viscosity above the “High Viscosity” range indicated in the above chart (e.g., LCs in the range of from about 1500 cp to 5000 cp, hereafter referred to as “ultra-high” viscosity) for mixing with water to prepare RTU fire retardant products (by comparison, the PHOS-CHEK® LC95 series and LCE20-FX liquid concentrates noted above in the BACKGROUND section have viscosities in a range of from about 100 to 400 cP, which falls into the “Low viscosity” range indicated in the above chart).

[0014] Regarding the use of “ultra-high” viscosity LCs as contemplated by the Inventors, some examples of such “ultra-high” viscosity LC fire retardants include, but are not limited to, magnesium chloride (MgCh) salt-containing LCs such as those disclosed in U.S. Patent No. 10,960,249, issued March 30, 2021, entitled “Long-term Fire Retardant With Corrosion Inhibitors and Methods for Making and Using Same” (Attorney Ref. FFRS-002US01), which patent is hereby incorporated herein by reference. It should be appreciated that other LCs such as those disclosed in one or more of the following U.S. patents, patent publications, or patent applications, each of which is hereby incorporated herein by reference in their entirety for all purposes, are also contemplated by the Inventors for use in connection with the inventive concepts disclosed herein: U.S. Patent Application No. 16 / 894,231, filed lune 5, 2020; U.S. Patent Application No. 16 / 894,214, filed June 5, 2020; U.S. Patent Application No. 17 / 105,019, filed November 25, 2020; U.S. Patent Application No. 17 / 213,770, filed March 26, 2021; U.S. Patent Application No. 17 / 213,780, filed March 26, 2021; U.S. Patent Application No. 17 / 531,269, filed November 19, 2021; U.S. Patent Application No. 18 / 060,943, filed December 1, 2022; U.S. Patent Application No. 17 / 031,024, filed September 24, 2020; U.S. Patent Application No. 17 / 214,266, filed March 26, 2021 ; U.S. Patent Application No. 17 / 53 1 ,295, filed November 19, 2021 ; U.S. Patent Application No. 18 / 060,941, filed December 1, 2022; U.S. Patent Application No. 17 / 458,002, filed August 26, 2021; U.S. Patent Application No. 17 / 845,569, filed June 21, 2022; U.S. Patent Application No. 18 / 182, 198, filed March 10, 2023; U.S. Patent Application No. 18 / 425,075, filed January 29, 2024; U.S. Patent Application No. 17 / 552,196, filed December 15, 2021; U.S. Patent Application No. 17 / 821 ,060, filed August 19, 2022; U.S. Patent Application No. 18 / 060,946, filed December 1, 2022; U.S. Patent Application No. 18 / 299,525, filed April 12, 2023; U.S. Patent Application No. 18 / 404,027, filed January 4, 2024; U.S. Patent Application No. 18 / 404,387, filed January 4, 2024; U.S. Patent Application No. 18 / 990,647, filed December 20, 2024; U.S. Patent Application No. 18 / 061,542, filed December 5, 2022; U.S. Patent Application No. 18 / 450,892, filed August 16, 2023; U.S. Patent Application No. 18 / 602,657, filed March 12, 2024; U.S. Patent Application No. 18 / 908,107, filed October 7, 2024; U.S. Provisional Patent Application No.62 / 858,640, filed June 7, 2019; U.S. Provisional Patent Application No. 62 / 989,350, filed March 13, 2020; U.S. Provisional Patent Application No. 63 / 024,040, filed May 13, 2020; U.S. Provisional Patent Application No. 63 / 325,876, filed March 31, 2022; U.S. Provisional Patent Application No. 63 / 028,765, filed May 22, 2020; U.S. Provisional Patent Application No. 63 / 140,657, filed January 22, 2021; and / or U.S. Provisional Patent Application No. 63 / 686,448, filed August 23, 2024.

[0015] LC fire retardants having ultra-high viscosity in the range of from about 1500 cP to 5000 cP present particular challenges in the preparation of RTU fire retardant products, based at least in part on the effect that a significantly higher viscosity has on the flow rate of the LC fire retardant.

[0016] More specifically, as would be readily appreciated by those of skill in the art, the Poiseuille Law of fluid dynamics provides a relationship between the viscosity of a fluid (i.e., an incompressible Newtonian fluid in laminar flow), a length of cylindrical pipe of constant circular cross-section through which the fluid flows and the pressure drop due to the viscosity of the fluid, as follows:Poiseuille's Law CalculationPressure difference x radius4Volume Flowrate = - 3 -— x viscosity x length

[0017] From the foregoing, it may be generally appreciated that viscosity is inversely proportional to flow rate, ft is also understood that Poiseuille’s Law does not apply in the limit of very low viscosity and wide and / or short pipe (e g., low viscosity or a wide pipe may result in turbulent flow, requiring a more complex relationship; however, even when turbulence is a factor, Poiseuille's Law provides a reasonable approximation of the how flow rate changes with viscosity of the fluid and pipe radius).

[0018] With reference to FIG. 1, in a conventional LC mix plant typically there is a loading pump, downstream of a manually-operated proportioning valve, to pump RTU fire retardant product into an airtanker. The manually-operated proportioning valve in turn is coupled via pipes to an LC tank and a water tank respectively. A pressure (or suction) provided by the gas-powered loading pump is exerted on both the water and the LC to draw these constituents through the pipes and the manually-operated proportioning valve so as to create the RTU product.

[0019] In particular, a first pressure exerted by the water in the water tank (referred to herein as “water head pressure”) and a second pressure (or suction) exerted by the pump provide the pressure difference in Poiseuille’s Law shown above that in turn affects the volume flowrate of water in the mix plant. Similarly, a third pressure exerted by the LC in the LC tank (referred to herein as “LC head pressure”) and the second pressure (or suction) exerted by the pump provide the pressure difference that in turn affects the volume flowrate of LC in the mix plant. For relatively lower viscosity LCs (e g., the PHOS-CHEK® LC95 series and LCE20-FX liquid concentrates), the action of the pump on both the water and the LC results in sufficiently similar respective flow rates of the LC and the water (given similar or identical length and radius of respective pipes used to carry the water and the LC).

[0020] Under these conditions of relatively similar viscosity constituents, a particular mix ratio of the LC and water may be effectively achieved to create the RTU product by manual operation of the proportioning valve. In particular, the manually-operated proportioning valve generally is positioned by a mix master to vary a first aperture size within the valve for the water and a second aperture size within the valve for the LC fire retardant (which essentially changes the radius in Poiseuille’s Law above for each of the LC and the water). The varied aperture sizes in turn adjust the respective flow rates of the constituents as they mix in the valve so as to achieve the specified mix-ratio for the RTU product. Thus, a ratio of the aperture size for the water and the aperture size for the LC within the valve generally correlates to a specified mix-ratio for the RTU fire retardant product.

[0021] However, the Inventors have recognized and appreciated that for ultra-high viscosity LC fire retardants (e.g., LCs having viscosities in the range of 1500 cp to 5000 cp), it is significantly more challenging to achieve specified mix-ratios to create an RTU fire retardant product using a conventional manually-operated proportioning valve.

[0022] More specifically, with reference again to Poiseuille’s Law illustrated above, the significantly different viscosities between an ultra-high viscosity LC fire retardant and water would result in significantly different respective flow rates of LC fire retardant and water entering into the proportioning valve - this would be the case assuming identical or similar pipe radius and length (e g., consider the difference between drinking a thick milk shake and a glass of milk using identical straws) and similar pressure differences for both the LC and the water (created by the loading pump and assuming similar head pressures of the LC and the water). This prospective difference in respective flow rates under these disparate-viscosity conditions is further complicated by recognizing that the assumption of similar head pressures does not apply; in particular, given the ultra-high viscosity of the LC fire retardant, the head pressure of the LC in the LC tank and the head pressure of the water in the water tank may be significantly different. These circumstances are complicated yet further by a constantly changing head pressure of the LC in the LC tank as more and more LC fire retardant is used up from the LC tank to create the RTU fire retardant product.

[0023] The Inventors have appreciated that, given the foregoing circumstances of disparate viscosities for LC and water, respectively, and changing head pressure of the LC, a manually-operated proportioning valve employed in a conventional LC mix plant as shown in FIG. 1 will be ineffective at reliably mixing an ultra-high viscosity LC and water to create RTU product. In particular, the Inventors have recognized that a proportioning valve of an LC mix plant needs to be dynamically operated to periodically change (e g., in some instances continuously change) the respective aperture sizes for an ultra-high viscosity LC fire retardant and the water within the valve to accordingly adjust corresponding flow rates so as to effectively achieve a specified mix-ratio and desired concentration of retardant salt in the RTU fire retardant product. More generally, the Inventors have recognized the need to dynamically control the respective flow rates of an ultra- high viscosity LC fire retardant and water (whether or not a proportioning valve is used to mix these constituents), particularly in view of the significant viscosity differences and a constantly changing head pressure of the LC in the LC tank.

[0024] In view of the foregoing, the inventive concepts disclosed herein are directed to improved mix plants for dilution and effective mixing of high viscosity long-term fire retardant liquid concentrates with water to produce RTU fire retardant product with a desired concentration of retardant salt. In example implementations, effective mixing of high viscosity LCs and water is achieved in part via automated feedback control of respective flow rates of the LC and the water. To facilitate improved quality control of the RTU product, in-line sensing of the RTU product is employed to regularly measure and digitally record one or more parameters representing a concentration of retardant salt in the RTU product as it is produced. One or more signals representing the measured parameter(s) are used as feedback to automatically adjust flow rates of the LC and the water so as to achieve a target concentration (e.g., weight percent) of retardant salt in the RTU product and a target flow rate for the RTU product (to facilitate loading into an airtanker).

[0025] In some aspects, the techniques described herein relate to a mobile mix plant for deployment at an airtanker base to provide a ready-to-use (RTU) fire retardant product containing at least one fire retardant salt for loading onto an airtanker, the mobile mix plant including: a water inlet for coupling to a water source to provide water for the mix plant; a power connection for coupling to at least one power source for the mobile mix plant; at least one mobile liquid concentrate (LC) tank to hold a liquid concentrate (LC) fire retardant containing the at least one fire retardant salt; an automated proportional mixing valve, fluidically coupled to the water inlet and the at least one mobile LC tank, to mix the water and the LC fire retardant and thereby form the RTU fire retardant product; at least one conduit, fluidically coupled to the automated proportional mixing valve and a discharge flow meter, to carry the RTU fire retardant product from the automated proportional mixing valve; at least one loading pump, fluidically coupled to the at least one conduit, to pump the RTU fire retardant product through the at least one conduit; an inline sensor, positioned in the at least one conduit between the automated proportional mixing valve and the discharge flow meter so as to be in fluidic contact with the RTU fire retardant product, to measure a quality value of the RTU fire retardant product in the at least one conduit; at least one controller, coupled to the in-line sensor and the automated proportional mixing valve, to automatically adjust at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured bythe in-line sensor; and a containment apparatus to provide a physical boundary around at least a portion of the mobile mix plant including the at least one mobile LC tank.

[0026] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one mobile LC tank is configured to agitate the LC fire retardant, when the LC fire retardant is present in the at least one mobile LC tank, without the LC fire retardant being circulated out of and back into the at least one mobile LC tank.

[0027] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one mobile LC tank includes at least one in-tank mechanical agitator.

[0028] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one in-tank mechanical agitator includes at least one agitator motor mounted to the at least one mobile LC tank.

[0029] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one in-tank mechanical agitator further includes: a shaft coupled to the at least one agitator motor and extending from a surface of the at least one mobile LC tank; and at least one blade coupled to the shaft.

[0030] In some aspects, the techniques described herein relate to a mobile mix plant through claim 5, wherein the at least one controller is coupled to the at least one in-tank mechanical agitator to control the at least one in-tank mechanical agitator.

[0031] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one controller is configured to control the at least one in-tank mechanical agitator according to an automated agitation schedule.

[0032] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one mobile LC tank includes at least one lifting system to facilitate connection of the at least one mobile LC tank with a transport vehicle to move the at least one LC tank.

[0033] In some aspects, the techniques described herein relate to a mobile mix plant, further including at least one mobile water pump coupled to the water inlet and the water source.

[0034] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the water source to which the water inlet is coupled includes at least one of: a fire hydrant; a municipal water line; a well; a water tower; an external water tank; or a surface water source pressurized by gravity or a pump. 1.

[0035] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one mobile LC tank includes at least one epoxy-based interior coating to reduce or mitigate corrosion.

[0036] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one mobile LC tank includes at least one tank level sensor to detect a quantity of contents held in the at least one mobile LC tank.

[0037] In some aspects, the techniques described herein relate to the mobile mix plant, further including at least one recirculation pump, coupled to the at least one mobile LC tank, to recirculate the LC fire retardant.

[0038] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one power source is a power grid, and wherein the power connection is coupled to the power grid.

[0039] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one power source includes at least one mobile generator, and wherein the mobile mix plant includes the at least one mobile generator.

[0040] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one loading pump includes an electric centrifugal pump with a horsepower rating in a range of from 10 horsepower to 100 horsepower.

[0041] In some aspects, the techniques described herein relate to the mobile mix plant, further including at least one non-electric mobile backup pump.

[0042] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the at least one non-electric mobile backup pump includes at least one of a gas-powered pump, a diesel-powered pump, a natural gas-powered pump, or a hydrogen-powered pump.

[0043] In some aspects, the techniques described herein relate to a mobile mix plant or claim 18, further including a backup loop fluidically coupled to the non-electric mobile backup pump, the automated proportional mixing valve, and the at least one conduit.

[0044] In some aspects, the techniques described herein relate to a mobile mix plant, further including at least one isolation valve coupled to the backup loop and operable to isolate the at least one loading pump from the backup loop.

[0045] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate of at least 200 gallons / minute.

[0046] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate in a range of from 200 gallons / minute to 500 gallons / minute.

[0047] In some aspects, the techniques described herein relate to the mobile mix plant, wherein: the at least one loading pump is communicatively coupled to the at least one controller and is responsive to at least one pump control signal output by the at least one controller to control a flow rate of the at least one loading pump.

[0048] In some aspects, the techniques described herein relate to the mobile mix plant, further including an internal flow meter coupled to the at least one conduit between the automatic proportional mixing valve and the discharge flow meter.

[0049] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the internal flow meter includes one of an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.

[0050] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the internal flow meter includes a Coriolis flow meter.

[0051] In some aspects, the techniques described herein relate to the mobile mix plant, further including the discharge flow meter.

[0052] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the discharge flow meter is one of a micromotion mass flow meter or a Coriolis flow meter.

[0053] In some aspects, the techniques described herein relate to a mobile mix plant or claim 28, wherein: the at least one controller is communicatively coupled to the in-line sensor, the flow meter and the automated proportional mixing valve, to automatically adjust the at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor and an in-line density of the RTU fire retardant product measured by the flow meter.

[0054] In some aspects, the techniques described herein relate to the mobile mix plant, wherein the quality value of the RTU fire retardant product in the at least one conduit as measured by the in-line sensor includes at least one of: a refractive index of the RTU fire retardant product; a viscosity of the RTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

[0055] In some aspects, the techniques described herein relate to a mobile mix plant, wherein the in-line sensor includes an in-line refractometer, and wherein the quality value of the RTU fire retardant product in the at least one conduit includes at least the refractive index of the RTU fire retardant product.

[0056] In some aspects, the techniques described herein relate to the mobile mix plant, further including at least one communication interface to communicatively couple the at least one controller to the Internet and to provide wireless data access proximate to the mobile mix plant to facilitate at least one of remote control, wireless updating, or troubleshooting of the mobile mix plant.

[0057] In some aspects, the techniques described herein relate to the mobile mix plant, wherein: the containment apparatus provides a secondary container for contents stored in the at least one LC tank; and the containment apparatus is configured to contain all of the contents of the largest tank of the at least one LC tank.

[0058] In some aspects, the techniques described herein relate to a method of operating a mobile mix plant for combining liquid concentrate (LC) fire retardant and water to create a ready -to-use (RTU) fire retardant product, the method including: disposing, in a liquid concentrate (LC) tank, the LC fire retardant; fluidically coupling the LC fire retardant with water through an automated proportional mixing valve; pumping the LC fire retardant through the automated proportional mixing valve and into a conduit to mix the LC fire retardant with water, thereby forming the RTUfire retardant product; measuring, by a first sensor, a quality value of the RTU fire retardant product in the conduit; and adjusting, by a controller, the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based at least in part on the quality value.

[0059] In some aspects, the techniques described herein relate to a method, wherein the quality value of the RTU fire retardant product includes at least one of: a refractive index of the RTU fire retardant product; a viscosity of the RTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

[0060] In some aspects, the techniques described herein relate to a method, further including: receiving, by a controller, a plurality of measurements from a corresponding plurality of refractive index sensors disposed in the LC tank, the plurality of measurements indicating a refractive index of an LC fire retardant contained in the tank; determining, by the controller, that a difference between each measurement of the plurality of measurements exceeds a threshold value; and controlling, by the controller, at least one of a mechanical agitator or a recirculation pump to mix the LC fire retardant in response to the difference exceeding the threshold.

[0061] In some aspects, the techniques described herein relate to a method, further including: determining, by the controller, a current drawn by a motor mechanically coupled to the mechanical agitator when the mechanical agitator mixes the LC fire retardant; calculating, by the controller and based on the determined current, a viscosity of the LC fire retardant.

[0062] In some aspects, the techniques described herein relate to a method, further including: in response to determining that the viscosity of the LC fire retardant is below a threshold, transmitting a notification indicating a status of the LC fire retardant.

[0063] In some aspects, the techniques described herein relate to a method, further including: lifting, by a lifting system integrated into the LC tank, at least a portion of the LC tank; mechanically coupling a transport vehicle to the portion of the LC tank; and transporting the LC tank from a first location to a second location.

[0064] In some aspects, the techniques described herein relate to a method, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate of at least 200 gallons / minute.

[0065] In some aspects, the techniques described herein relate to a method, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate between 200 gallons / minute and 500 gallons / minute.

[0066] In some aspects, the techniques described herein relate to a method, further including adjusting the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based on an in-line density of the RTU fire retardant product measured by a flow meter.

[0067] In some aspects, the techniques described herein relate to a method, wherein the flow meter includes at least one of a discharge flow meter, a Coriolis flow meter, an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.

[0068] All combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are part of the inventive subject matter disclosed herein. The terminology used herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally and / or structurally similar elements).

[0070] FIG. 1 illustrates respective elements of a conventional LC mix plant at an airtanker base.

[0071] FIG. 2 illustrates a block diagram of a mixing system for preparing a long-term fire retardant for application to a fire, according to one example implementation.

[0072] FIG. 3 illustrates a mixing system in accordance with the present technology.

[0073] FIG. 4A illustrates an additional perspective view of the mixing system of FIG. 3.

[0074] FIG. 4B illustrates an additional perspective view of the mixing system of FIG. 3.

[0075] FIG. 5 illustrates an additional perspective view of the mixing system of FIG. 3.

[0076] FIG. 6 illustrates a tank having in-tank mechanical agitators and multiple compartments in accordance with the present technology.

[0077] FIG. 7 illustrates a tank having a built-in lifting system in accordance with the present technology.

[0078] FIG. 8 illustrates the tank of FIG. 7 when the built-in lifting system is activated.

[0079] FIG. 9 illustrates a longitudinal view of a tank having one or more in-tank mechanical agitators in accordance with the present technology.

[0080] FIG. 10 illustrates an external view of a multi -compartment tank in accordance with the present technology.

[0081] FIG. 11 illustrates an additional external view of the multi-compartment tank of FIG. 10.

[0082] FIG. 12 is a flowchart of an example method for operating a mobile mix plant for combining liquid concentrate (LC) fire retardant and water to create a ready -to-use (RTLJ) fire retardant product.DETAILED DESCRIPTIONMixing System

[0083] FIG. 2 illustrates an inventive mixing system 100 (also referred to as a mix plant) for preparing (e g., mixing or diluting) a long-term fire retardant for application to a fire, according to one example implementation. The mixing system 100 may be used for preparing a long-term fire retardant diluted product by diluting a long-term fire retardant liquid concentrate with a solvent such as water. The resulting diluted product is in a form suitable to fight (e.g., suppress, retard, contain) forest fires via aerial- or ground-based applications. In some versions, the mixing system 100 may be located at or near a firefighting dispatch location (e.g., at an airfield proximate to a forest fire), so that the mixing system 100 may prepare the fire retardant diluted product for convenient deployment to the forest fire. In other versions, the mixing system 100 may be disposed at other locations relevant for firefighting or storing fire retardants.

[0084] The fire retardant liquid concentrate, described in more detail below, is a viscous liquid having one or more fire retardant compounds dissolved in water at a high concentration. For example, the viscosity of the liquid concentrate at ambient temperature may be in a range of from about 50 centipoise (cP) to about 5,000 cP, or more generally in a range of from about 10 centipoise (cP) to about 10,000 cP. As an illustrative comparison, fluids that fall within this viscosity range include glycerin, corn syrup, and honey. As a reference, the viscosity of water at ambient temperature is about 1 cP.

[0085] To produce the fire retardant diluted product suitable for application to a fire, the liquid concentrate is mixed with water for dilution. However, because of the relatively higher viscosity of the fire retardant liquid concentrate, the Inventors have recognized and appreciated that conventionally it is difficult to mix the liquid concentrate with water in precise mixing ratios. This problem is further exacerbated when mixing the liquid concentrate and water at relatively higher flow rates (e.g., 500 gallons per minute). In spite of these conventional mixing challenges, the ability to effectively control the mixing ration of liquid concentrate to water is important to ensure that the diluted product meets the specifications set by fire management services. For example, the US Forest Service specifies standards for a forest fire retardant to qualify for use by the US Forest Service, including the standards described in Forest Service Specification 5100-304d, as well as Interim Amendment to Federal Specification 5100-304d (released October 25, 2024), both of which are hereby incorporated by reference in their entirety.

[0086] The mixing system 100 addresses these problems by providing a mixing system that can effectively and accurately mix liquid concentrate with water at a desired volume-to-volume (e.g., gallon-to-gallon) water-to-liquid concentrate mixing ratio in a range of from about 45: 1 to about 0.2: 1 (waterliquid concentrate). In one aspect, the mixing ratio may be varied throughout this range in significantly small increments (e.g., essentially continuously), notwithstanding significant viscosity differences between the liquid concentrate and the water. In another aspect, the mixing system 100 creates a diluted product at a production rate (also called a flow rate) in a range of about 100 gallons per minute (gpm) to about 1200 gpm (examples of production rates include, but are not limited to, 100 gpm, 500 gpm, 1000 gpm, or 1200 gpm).

[0087] As discussed in further detail below, in one example implementation the mixing system 100 includes one or more “in-line” sensors, i.e., disposed in the flow of the diluted product, to sense one or more measurable characteristics of the diluted product. The one or more sensed characteristics are input to a controller that in turn controls one or more valves and / or one or more pumps to vary a flow rate of either or both of the water and the liquid concentrate so as to in turn vary the mixing ratio, based at least in part on the one or more sensed characteristics of the diluted product.

[0088] Mixing system 100 may include an LC container 120 (equivalently, tank 120) at least partially filled with liquid concentrate 122 and a solvent container 130 (equivalently, water tank 130) at least partially filled with solvent 132. Solvent 132 may be, e.g., water, and may be added to solvent container 130 through a solvent source 138. A distribution of solvent 132 from solvent source 138 may be controlled by a float valve 136, which may be configured to distribute water into solvent container 130 based on a level of solvent 132, e g., to distribute solvent 132 into solvent container 130 when a level of solvent 132 is below a threshold. Float valve 136 may include a float 137 configured to float on top of solvent 132 and be displaced by solvent 132. When a level of solvent 132 is high enough, float 137 will be displaced such that float valve 136 is closed and solvent 132 ceases flowing.

[0089] Liquid concentrate 122 may be any suitable fire retardant compound in accordance with the present technology, e.g., a fire retardant compound listed in Table 1. Liquid concentrate 122 may have a suitable viscosity as discussed above, e.g., between about 1500 cP and about 5000 cP, although lower viscosities are possible, e g., about 1 cP to about 50 cP, about 25 cP to about 75 cP, about 50 cP to about 150 cP, about 100 cP to about 800 cP, about 500 cP to about 1000 cP, about 800 cP to about 1500 cP, or the like. In an aspect, viscosity values listed herein may accord to dynamic viscosities as determined by a Brookfield viscometer at 60 revolutions per minute and 21° C with an appropriate spindle.

[0090] Each of liquid concentrate 122 and solvent 132 may be apportioned through respective distribution valves. For example, LC container 120 may include LC distribution valve 124 and solvent container 130 may include solvent distribution valve 134. LC distribution valve 124 and solvent distribution valve 134 may be communicatively coupled to a controller 110, which may be configured to transmit one or more signals controlling an operation of LC distribution valve 124 and / or solvent distribution valve 134. For example, controller 110 may cause LC distribution valve 124 and solvent distribution valve 134 to open and allow a mixing of liquid concentrate 122 and solvent 132 to form a final diluted product, which may consume both the solvent (e.g., water) and the LC fire retardant as the two mix to form the final diluted product (e.g., an RTU fire retardant product).

[0091] Controller 110 may be communicatively coupled to a user interface 112, which may be a computer, tablet, laptop, desktop, smartphone, touch screen, kiosk, or any suitable device for receiving information and / or instructions from a user. User interface 112 may include a data storage and / or memory for storing information, such as information related to an operation of mixing system 100. For example, user interface 112 may be used to store a digital record of at leastsome of a plurality of measurements related to refractive index, flow rate, viscosity, pH, density, or any suitable measurement.

[0092] A user may input one or more parameter values for a final diluted product, which may be created by mixing liquid concentrate 122 and solvent 132 in accordance with the parameter values. For example, a user may input parameter values for one or more of refractive index, density, viscosity, pH, mass flow, conductivity, flow rate, type of liquid concentrate 122, type of solvent 132, and / or selective ion concentration of the final diluted product.

[0093] Controller 110 may be communicatively coupled to one or more external computing systems such as computing system 114. Computing system 114 may include one or more remote computers, a cloud computing system, computing hardware in a data center or other location, an artificial intelligence (Al) cluster, or any suitable computing system for performing logical operations, data transfer, and other suitable computer functionality.

[0094] Controller 110 may utilize artificial intelligence to control, monitor, report on, analyze, or otherwise maintain mixing system 100. Controller 110 may receive some or substantially all data generated by sensors, machinery, systems, processes, operations, etc., of mixing system 100. Controller 1 10 may implement or communicate with one or more Al or machine learning (ML) models, agents, systems, etc., to analyze data from sensors in mixing system 100 and determine trends, control operations of mixing system 100, improve inventory usage, implement more effective maintenance routines, and so on. Controller 110 may instantiate, operate, control, interact with, or otherwise utilize one or more Al agents, ML models, or the like, to determine and improve energy efficiency associated with one or more aspects of mixing system 100 (e.g., of backup generators), electrical characteristics (such as current and / or voltage) of one or more in-tank mixers, maintenance needs or equipment failure rates, mixing tolerances, and so on.

[0095] For example, controller 110 may utilize an Al agent to monitor current drawn by one or more in-tank mechanical agitators 346. Controller 110 may determine that a current draw trend for a first mechanical agitator of the one or more in-tank mechanical agitators 346 differs significantly from the current drawn by the other mechanical agitators, and may accordingly transmit a notification to one or more system users, maintenance personnel, or other computing systems indicating that the first mechanical agitator may have an issue such as a bad bearing. Controller 110 may continuously monitor any suitable data associated with mixing system 100 and provide a corresponding alert or notification when data indicates that an aspect of mixing system 100 requires attention from an appropriate entity. Controller 110, utilizing a suitable Al entity, may provide one or more reports regarding mixing system 100 operation, equipment health, product quality, product parameters, system usage, product usage, or any suitable subject.

[0096] Controller 110 may additionally or alternatively utilize Al to monitor system-external data such as weather, aircraft availability, local and / or national fire activity, fire retardant component availability and cost, storage availability, etc., in order to more accurately predict long-term trends and demand for fire retardant products provided through mixing system 100. An Al agent may additionally or alternatively act as a virtual assistant manager for mixing system 100 and provide a person or other Al entity acting as a principal manager of mixing system 100 with notifications,alerts, suggestions, etc., for the operation of some or all portions of mixing system 100. Furthermore, an Al agent may generate reports on equipment health, fire retardant product quality (e.g., mixing parameters such as viscosity, product level in a tank, temperature, refractive index, etc.), fire retardant usage, etc.

[0097] Liquid concentrate 122 and solvent 132 may flow through piping 170 (equivalently, conduit 170) . Mixing system 100 may include one or more pumps 150, including LC pump 150a, solvent pump 150b, and final diluted product pump 150c. Pumps 150 may be any suitable type of pump, e.g., a mechanical pump, a siphon pump, etc. Each respective pump of pumps 150 may be disposed downstream of LC distribution valve 124 and solvent distribution valve 134. In an alternative aspect, LC pump 150a may be disposed upstream of LC distribution valve 124 and solvent pump 150b may be disposed upstream of solvent pump 150b.

[0098] Each pump of pumps 150 may be further configured to mix the diluted product discharged from the outlet port of the proportional mixing valve. Each pump may have a variable pumping speed. Controller 110 may be further communicatively coupled to each pump and further configured to modulate the variable pumping speed based on sensor data from pumps 150 and / or other sensors within mixing system 100. Mixing system 100 may further include a static mixer fluidically coupled to a mixing junction 172, Final diluted product pump 150c, and / or final diluted product valve 174 to mix the final diluted product discharged from the outlet port of the final diluted product valve 174.

[0099] The mixing junction 172 may include a main body defining a cavity and having a first inlet port for liquid concentrate to enter the cavity, a second inlet port for water to enter the cavity, and an outlet port to discharge a mixture of the liquid concentrate and the water. The mixing junction 172 may further include a modulating element disposed within the cavity. The modulating element may be movable within the cavity and positioned to partially or fully obstruct the first inlet port and / or the second inlet port in order to modify the proportion of liquid concentrate and / or water entering the cavity and, thus, a mixing ratio of the liquid concentrate and the water.

[0100] The modulating element may be coupled to an actuator, which may be used to adjust the modulating element (e.g., by moving or rotating the modulating element). The actuator may be various actuators including, but not limited to, an electric motor, a solenoid, a pneumatic actuator, a hydraulic actuator, and any combinations of the foregoing. The actuator may comprise a handle for manual actuation. The actuator may also be communicatively coupled to the controller 110 to receive control signals from the controller 110 and adjust the modulating element based on the control signals. For example, the control signals may be generated based on one or more conditions of the final diluted product discharged from the outlet port measured by the one or more sensors of measurement device 140.

[0101] As illustrated in FIG. 2, one or more signals from measurement device 140, which may represent an in-line concentration measurement of the final diluted product are input to controller I 10. The controller 1 10 in turn controls the flow of one or more of the liquid concentrate 122, the solvent 132, or the final diluted product based on the in-line concentration measurement. The controller 110 optionally may also receive another signal provided by a flow meter to facilitateautomated control of the flow of the liquid concentrate 122, solvent 132, and / or the final diluted product. In one example implementation, measurement device 140 may include an in-line refractometer configured to measure a concentration of final diluted product after mixing at mixing junction 172; examples of refractometers effectively employed by the Inventors for this purpose include, but are not limited to, the L-Rix series manufactured by Anton Paar.

[0102] Mixing system 100 enables automated variable flow control for each of the liquid concentrate 122, solvent 132, and final diluted product based on one or more signals provided by the controller 1 10, wherein these one or more signals in turn are based on one or more in-line concentration measurements from measurement device 140 (e.g., in-line refractive index measurements provided by an in-line refractometer, one or more signals provided by a flow meter, etc.). It should be appreciated that in various inventive implementations, such automated variable flow control may be achieved in multiple ways. In an embodiment, mixing system 100 may include a plurality of measurement devices 140 disposed on various portions of piping 170, LC container 120, solvent container 130, or any suitable portion of mixing system 100.

[0103] One or more sensors of measurement device 140 may be disposed in-line with the flow of final diluted product to continuously and directly monitor the properties of the final diluted product produced by the mixing system. This may be accomplished, for example, by placing the one or more sensors within piping 170 or tube carrying the final diluted product, within a side-stream sampling line fluidically coupled to the main pipe or tube, or onto a window coupled to piping 170. A flow rate of a final diluted product may be measured by flow meter 160, which may be disposed at a portion of piping 170 adj cent to an aircraft 180 (such as a firefighting air tanker) or an RTU product container 190.

[0104] A final diluted product may be stored or loaded after mixing. For example, the final diluted product may be stored as RTU product 192 in RTU product container 190. RTU product container 190 may be used to provide storage for RTU product 192 (e g., hours, days, weeks, months, or the like). A final diluted product may be loaded onto aircraft 180 via loading hose 176. A final diluted product may be loaded onto aircraft 180 directly after mixing through mixing junction 172 or may be loaded onto aircraft 180 from RTU product container 190.

[0105] In one non-limiting example, the one or more sensors of measurement device 140 may include a refractometer to measure the refractive index of the diluted product, which may vary appreciably in response to small changes in the mixing ratio of the fire retardant liquid concentrate and water and is less affected by the presence of bubbles in the diluted product. Although the components of a refractometer are generally susceptible to corrosive damage when exposed to corrosive compounds, such as magnesium chloride or, more generally, halides, phosphates, sulfates, carbonates, and / or hydroxides, the mixing systems disclosed herein may reduce or, in some instances, mitigate corrosive damage to the refractometer by using liquid concentrates that include corrosion inhibitors.

[0106] Controller 1 10 may be communicatively coupled to pumps 150 and configured to control a flow of liquid concentrate 122, solvent 132, and final diluted product using one or more of pumps 150, LC distribution valve 124, solvent distribution valve 134, final diluted product valve 174, andmeasurements from measurement device 140. For example, controller 110 may increase or decrease a speed of LC pump 150a based on one or more refractive index measurements indicating a concentration of liquid concentrate 122 in a final diluted product.[0107J For example, in one inventive implementation, respective variable pumps responsive to the controller 110 may be employed for the LC, the water, and the RTU product, wherein a mixing junction for the LC, the water, and the RTU product comprises a T-shaped or Y-shaped junction (also referred to conventionally as a “pipe wye”).

[0108] In another inventive example, respective adjustable aperture valves responsive to the controller 110 may be employed for each of the LC and the water, together with a T-shaped or Y- shaped pipe wye and a single pump for the RTU product (which also may be responsive to the controller 110).

[0109] In yet another example, an automated proportional mixing valve responsive to the controller 110 may be employed together with a single pump for the RTU product (which also may be responsive to the controller 110), downstream of the automated proportional mixing valve; alternatively, an automated proportional mixing valve responsive to the controller 110 may be employed with respective pumps for the LC and the water (which also may be responsive to the controller 110), upstream of the automated proportional mixing valve. Other permutations and combinations of the foregoing arrangements also are contemplated by the Inventors and would be readily understood by those of skill in the art with the benefit of this disclosure.

[0110] Following below are two non-limiting illustrative examples of inventive systems and methods according to the present disclosure:Example 1

[0111] A mixing system comprising:

[0112] A water source:

[0113] A tank that is equipped with a float valve or other fluid level sensor that automatically activates when the water level drops below a certain level to start refilling the tank and maintain a minimum head pressure and an actuated valve on the outlet of the tank that is connected by a pipe to one port of an actuated proportional mixing valve. The actuated valve on the water tank is connected to a controller that can open or close the valve by sending a signal.

[0114] A liquid concentrate source:

[0115] A tank with liquid concentrate (LC) with an actuated valve on the tank and a pipe that connects the valve on the LC tank to the one port of an actuated proportional mixing valve. The actuated valve on the LC tank is connected to a controller that can open or close the valve by sending a signal.

[0116] An actuated proportional mixing valve connected to a controller, and with one input port connected by a pipe to an actuated valve on the water source and second input port connected by a pipe to an actuated valve on the liquid concentrate (LC) source, and an output port. The actuated proportional mixing valve is connected to a controller that can adjust the proportional mixing valveby sending a signal and can adjust the mix ratio such that only water is passed through the proportional mixing valve, only LC is passed through the proportional mixing valve, or any proportional ratio of water to LC between 0% and 100% will pass through the proportional mixing valve.

[0117] A pump, such as a centrifugal pump, wherein the intake port is connected to the output of the actuated proportional mixing valve and the discharge is connected to a storage tank with pipes. The pump is connected to a centralized controller with a variable frequency drive that can activate or deactivate the pump with a signal and can control the flow rate of the pump between 0% and 100% of its output capacity after activating it.

[0118] A refractive index sensor that is mounted downstream of the discharge of the pump inline with storage tank. The window of the refractive index sensor is in fluidic contact with the product in the pipe that connects the pump to the storage tank.

[0119] A controller that is connected to a power source, the actuated valve on the water source, the actuated valve on the LC source, at least one sensor, a variable frequency drive, and the pump.

[0120] A ready to use (RTU) long-term fire retardant is prepared by the following:

[0121] Power is provided to the system and the controller runs through an automated start-up routine to check connectivity to and status of each of the components and then provides a ready signal to the operator.

[0122] The operator will set initial parameters based on the specific retardant that is being mixed and the desired flow rate into the RTU retardant storage tank, and will command the system to run.

[0123] The system will then adjust the initial state of the proportional mixing valve to match the desired mix ratio for the LC, e.g. if the mix ratio for the LC is 1 gallon of LC to 2.4 gallons of water the proportional mixing valve will adjust to a configuration that will allow 2.4 times more water than LC to pass through the proportional mixing valve.

[0124] The controller will then send signals to open the actuated valves on the water source and the LC source.

[0125] The controller will then ramp up the pump to the desired flow rate that was input by the operator, which will pull in water and LC from their respective sources through the valves and pipes on the respective sources into the proportional mixing valve, combining them at the desired ratio. The combined fluids will then travel from the mixing valve through a section of pipe into the pump. The pump will help homogenize the mixture before sending it to the storage tank.

[0126] As the product is transferred to the storage tank it will flow past the refractive index sensor and be measured. The refractive index sensor will transmit the refractive index values of the mixed RTU product back to the controller where the measured value will be compared to the target value.

[0127] If the measured refractive index of the mixed ready to use product that is being transferred to the storage tank is within the tolerance that was entered by the operator the system will maintain all settings and continue to monitor the output readings of the refractive index sensor and operate until either the operator stops the system, a pre-set quantity of mixed ready to use retardant hasbeen produced, or the refractive index of the mixed ready to use retardant that is being transferred to the storage tank is out of tolerance.

[0128] If at any point the controller detects refractive index value that is out of tolerance, the system will respond accordingly. For example, if the refractive index value that the sensor is detecting is below the target value, the system will adjust the proportional mixing valve such that more concentrate and less water is allowed to pass through the proportional mixing valve. The adjustments will be made in small steps allowing for enough time after the adjustment at the proportional mixing valve for the mixed product with the new ratio to reach the refractive index sensor and the sensor to transmit the refractive index values back to the controller. If the adjustments made to the mixing ratio have brought the refractive index of the mixed product back into tolerance the system will maintain those values until either the operator stops the system, a pre-set quantity of mixed ready to use retardant has been produced, or the refractive index of the mixed ready to use retardant that is being transferred to the storage tank is out of tolerance. If the refractive index is still out of tolerance, the system will repeat the process adjusting the proportional mixing valve by another small step and waiting until the new refractive index value has been obtained and either maintain or repeat the process until the refractive index of the product being transferred to the storage tank is within tolerance. When the measured refractive index of the mixed ready to use product that is being transferred to the storage tank is within the tolerance that was entered by the operator, the system will maintain all settings and continue to monitor the output readings of the refractive index sensor and operate until either the operator stops the system, a pre-set quantity of mixed ready to use retardant has been produced, or the refractive index of the mixed ready to use retardant that is being transferred to the storage tank is out of tolerance.Example 2

[0129] A mixing system comprising:[01 AO] A water source:

[0131] A tank that is equipped with a float valve or other water level sensor that automatically activates when the water level drops below a certain level to start refilling the tank and maintain a minimum head pressure and an actuated valve on the outlet of the tank that is connected by a pipe to one port of an actuated proportional mixing valve. The actuated valve on the water tank is connected to a controller that can open or close the valve by sending a signal.

[0132] A liquid concentrate source:

[0133] A tank with liquid concentrate (LC) with an actuated valve on the tank and a pipe that connects the valve on the LC tank to the one port of an actuated proportional mixing valve. The actuated valve on the LC tank is connected to a controller that can open or close the valve by sending a signal.

[0134] An actuated proportional mixing valve connected to a controller, and with one input port connected by a pipe to an actuated valve on the water source and second input port connected by a pipe to an actuated valve on the liquid concentrate (LC) source, and an output port. The actuated proportional mixing valve is connected to a controller that can adjust the proportional mixing valveby sending a signal and can adjust the mix ratio such that only water is passed through the proportional mixing valve, only LC is passed through the proportional mixing valve, or any proportional ratio of water to LC between 0% and 100% will pass through the proportional mixing valve.

[0135] A pump, such as a centrifugal pump, wherein the intake port of the pump is fluidically coupled to the output of the actuated proportional mixing valve and the discharge is connected to a storage tank with pipes. The pump is communicatively coupled to a centralized controller with a variable frequency drive that can activate or deactivate the pump with a signal and can control the flow rate of the pump between 0% and 100% of its output capacity after activating it.

[0136] A refractive index sensor that is mounted downstream of the discharge of the pump inline with storage tank. The window of the refractive index sensor is in fluidic contact with the product in the pipe that connects the pump to the storage tank. One or more additional sensor sensors (density in this example) that is mounted downstream of the discharge of the pump in-line with storage tank. The sensor is mounted in the fluid stream.

[0137] A controller that is connected to a power source, the actuated valve on the water source, the actuated valve on the LC source, at least one sensor, a variable frequency drive, and the pump.

[0138] A ready to use (RTU) long-term fire retardant is prepared by the following:

[0139] Power is provided to the system and the controller runs through an automated start-up routine to check connectivity to and status of each of the components and then provides a ready signal to the operator.

[0140] The operator will set initial parameters based on the specific retardant that is being mixed and the desired flow rate into the RTU retardant storage tank, and will command the system to run.

[0141] The system will then adjust the initial state of the proportional mixing valve to match the desired mix ratio for the LC, e g. if the mix ratio for the LC is 1 gallon of LC to 2.4 gallons of water the proportional mixing valve will adjust to a configuration that will allow 2.4 times more water than LC to pass through the proportional mixing valve.

[0142] The controller will then send signals to open the actuated valves on the water source and the LC source.

[0143] The controller will then ramp up the pump to the desired flow rate that was input by the operator, which will pull in water and LC from their respective sources through the valves and pipes on the respective sources into the proportional mixing valve, combining them at the desired ratio. The combined fluids will then travel from the mixing valve through a section of pipe into the pump. The pump will help homogenize the mixture before sending it to the storage tank.

[0144] As the product is transferred to the storage tank it will flow past both the refractive index sensor and density sensors and will be measured. The refractive index sensor and density sensor will transmit the refractive index and density values of the mixed RTU product back to the controller where the measured values will be compared to the target value.

[0145] If both the measured refractive index and density of the mixed ready to use product that is being transferred to the storage tank is within the tolerance that was entered by the operator the system will maintain all settings and continue to monitor the output readings of the refractive index sensor and operate until either the operator stops the system, a pre-set quantity of mixed ready to use retardant has been produced, or the refractive index of the mixed ready to use retardant that is being transferred to the storage tank is out of tolerance.

[0146] If at any point the controller detects one of the sensors that is out of tolerance, the system will respond accordingly. For example, in one implementation, one or more sensors may be configured to provide a caution or warning of an out of tolerance condition but allow the system to continue to run without adjusting the proportional mixing valve; in a different example, one or more sensors may be configured to provide an ’’alarm” state if an out of tolerance condition exists, and adjust the proportional mixing valve. Following below are additional details of nonlimiting examples in which multiple sensors are employed:

[0147] A given sensor (refractive index or density) may be configured as a ‘warning’ sensor or an ‘alarm / correct’ sensor. Such a designation may apply to all values of a given sensor’s output outside of the tolerance range, or some values may be warning, and some alarm / correct (e g., within X% outside of the tolerance range would be warning, and beyond X% outside of the tolerance range would be alarm, where X can be 1, 5, or 10, for example).

[0148] For example, if the density is designated as warning and the refractive index is designated as alarm / correct, if the refractive index is within tolerance but the density is not, the system may send warnings to the user. The system will continue to run as normal until either the density is back within specification, the density meets an alarm / correct state, or the mixing is completed. If the refractive index is out of specification with the alarm / correct setting, if the controller detects that the refractive index value is above the desired target, the system will adjust the proportional mixing valve such that less concentrate and more water is allowed to pass through the proportional mixing valve.

[0149] One metric out of specification, others are acceptable. For example, if the controller detects that the refractive index value is out of tolerance, but the density is within tolerance, the system will determine if the refractive index is below or above the desired target. If the system is above the target, the system will adjust the proportional mixing valve such that less concentrate and more water is allowed to pass through the proportional mixing valve. Similarly, if the density is too high, the system will adjust the proportional mixing valve such that less concentrate and more water is allowed to pass through the proportional mixing valve.

[0150] Multiple metrics out of specification. If the controller detects that both the refractive index and density values are out of tolerance, the system will determine if the density and refractive index are below or above the desired target. If they require adjustment in the same direction (i.e. if they are both above the target), the system will adjust the proportional mixing valve such that less concentrate and more water is allowed to pass through the proportional mixing valve. Similarly, if both are too low, the system will adjust the proportional mixing valve such that more concentrate and less water is allowed to pass through the proportional mixing valve.

[0151] There are cases that may occur where one value is below the threshold and one is above. While this is unlikely to occur, the system should shut down and alert the user.

[0152] The adjustments described in a-e are made in small steps allowing for enough time after the adjustment at the proportional mixing valve for the mixed product with the new ratio to reach the refractive index sensor and the sensor to transmit the refractive index values back to the controller. As non-limiting examples, small steps of adjustment may include adjusting one or more flow rates by 0.5%, 1%, 5%, or 10%. A non-limiting example of an amount of time to allow a new ratio to reach the refractive index sensor may be on the order of milliseconds or a fraction of a second, such that in practice, the response of the feedback is essentially instantaneous. If the adjustments made to the mixing ratio have brought the sensor output of the mixed product back into tolerance the system will maintain those values until either the operator stops the system, a pre-set quantity of mixed ready to use retardant has been produced, or the mixed ready to use retardant that is being transferred to the storage tank is again out of tolerance. If the measured property is still out of tolerance, the system will repeat the process adjusting the proportional mixing valve by another small step and waiting until the new sensor output value has been obtained and either maintain or repeat the process until the refractive index of the product being transferred to the storage tank is within tolerance.

[0153] It should be appreciated that the foregoing example of using multiple sensors to provide feedback relating to a retardant salt concentration in the RTU fire retardant product is provided primarily for the purpose of illustration. In general, in various implementations involving multiple sensors, respective sensor output signals from multiple sensors may be combined mathematically (e.g., via the controller) to provide a “composite signal” that is used by the controller to provide a warning or alarm and otherwise adjust or maintain a current state of the proportional mixing valve. In this respect, it should be appreciated that the controller may have programmable logic capabilities to adjust or maintain multiple components of the disclosed system (e.g., proportional mixing valve, respective actuated valves on the water tank or LC tank, pump speed, etc.) based on an output provided by one or more sensors.

[0154] Flow meters: there may be two or more: In-line - electromagnetic, external - discharge (e.g., micro motion Coriolis).Mobile Retardant Base (“Mobile Mix Plant”)

[0155] With reference now to FIGS. 3 through 11, in another example implementation, the present disclosure is directed to mobile retardant base (“MRB”), also referred to herein as a “mobile mix plant” 300, for deployment at an airtanker base to provide a ready-to-use (RTU) fire retardant product containing one or more fire retardant salts for loading onto an airtanker. In various examples, the MRB / mobile mix plant described herein may be deployed on-demand as a temporary installation (e.g., as short as a few days) or alternatively as a long-term (e.g., multiple months or years) or essentially permanent installation at an airtanker base or other appropriate location.

[0156] As shown in FIG. 3, in one non-limiting example the mobile mix plant 300 may employ an automated proportional mixing valve 310 similar to that described above in connection withFIG. 2, together with one or more mobile liquid concentrate (LC) tanks 320, 330 to hold a liquid concentrate (LC) fire retardant containing the fire retardant salt(s). With reference for the moment to FIG. 5, the mobile mix plant also includes a water inlet 302 for coupling to a water source to provide water for the mix plant. It should be appreciated that, in some examples, the water source may be provided by a third-party, while in other examples the water source itself may form part of the mobile mix plant. Example water sources include, but are not limited to, a pressurized water line from an external water supply such as a fire hydrant, a municipal water line, a well, a water tower, a water tank, or a surface water source that is pressurized by either gravity or a pump.

[0157] Returning to FIG. 3, the automated proportional mixing valve 310 is fluidically coupled to the water inlet and the one or more mobile LC tanks to mix the water and the LC fire retardant and thereby form the RTU fire retardant product. A conduit 312 is fluidically coupled to the automated proportional mixing valve and a discharge flow meter 314A, as shown in FIG. 4A. The conduit 312 carries the RTU fire retardant product from the automated proportional mixing valve to one or more loading pumps 316 that is / are fluidically coupled to the conduit and which pump the RTU fire retardant product through the conduit.

[0158] As shown in FIG. 4B, the mobile mix plant further includes an in-line sensor 318, positioned in the conduit between the automated proportional mixing valve and the discharge flow meter so as to be in fluidic contact with the RTU fire retardant product. The in-line sensor 318 measures a quality value of the RTU fire retardant product in the conduit. As would be appreciated by one of skill in the art, the RTU fire retardant product may be characterized by a variety of parameters such as refractive index (i.e. for salt content), viscosity, density, and pH (all which parameters have suitable ranges that are defined by the USFS during qualification of an RTU fire retardant product). Accordingly, in various non-limiting examples, the quality value measured by an in-line sensor may include any one or more the aforementioned parameters, correspondingly measured by one or more devices suitable for measuring one or more of these parameters. In one particular example, the in-line sensor includes an in-line refractometer, and the quality value of the RTU fire retardant product in the conduit includes at least the refractive index of the RTU fire retardant product.

[0159] With reference again to FIG. 3, the mobile mix plant 300 further may include one or more controllers 390, coupled to the in-line sensor and the automated proportional mixing valve, to automatically adjust at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor. In some examples, the controller(s) automatically adjust one or more flow variables based at least in part on the quality value measured by the in-line sensor and an in-line density of the RTU fire retardant product measured by either the discharge flow meter or an internal flow meter. The mix plant also may include one or more communication interface 326 to communicatively couple the controller(s) to the Internet and to provide wireless data access proximate to the mobile mix plant to facilitate at least one of remote control, wireless updating, or troubleshooting of the mobile mix plant.

[0160] The mobile mix plant also includes a power connection 304 for coupling to at least one power source for the mobile mix plant, and a containment apparatus 322 to provide a physical boundary around at least a portion of the mobile mix plant including the one or more mobile LC tanks. In various example implementations, the containment apparatus 322 generally serves to contain various materials that may leak. Accordingly, in some examples, the containment apparatus may surround only the one or more mobile LC tanks, while in other examples the containment apparatus may surround the one or more mobile LC tanks and one or more other elements of the mobile mix plant. Additionally, FIG. 5 shows an optional flammables cabinet used for storing flammable materials such as acetone, gasoline, diesel fuel, or other materials that may be used to operate system 300 or a similar system.

[0161] Regarding a given mobile LC tank 320, 330 as shown in FIGS. 3 and 5, FIGS. 6-11 illustrate various details of one non-limiting example of a mobile LC tank 420 (which may be analogous to or the same as either or both of mobile LC tanks 320, 330) according to the inventive concepts disclosed herein.

[0162] In one aspect, a mobile LC tank 420 is configured to in some manner agitate the LC fire retardant when the LC fire retardant is present in the tank 420. Various forms of agitation are contemplated as suitable for implementation in connection with the tank 420, including those forms that may or may not require external recirculation (e.g., using an external recirculation pump). External recirculation systems may include hoses and seals that are prone to failure, particularly in cold weather. In the event of such a failure, some or all of the LC fire retardant may be lost from tank 420. Thus, the inventors have recognized and appreciated the advantages conferred by including one or more internal mixing mechanisms in an exemplary tank.

[0163] For example, mechanical, fluidic, and / or pneumatic agitation may be employed; regarding pneumatic agitation, compressed air may be released into the tank, and one or more bubbles arising from the compressed air may induce in-tank mixing as the bubbles traverse (e.g., rise up and through) the LC fire retardant stored in the tank.

[0164] In one particular example, agitation of the LC tire retardant is accomplished without the LC fire retardant being circulated out of and back into the mobile LC tank. To this end, as shown in FIG. 6 for example, the tank 420 includes one or more in-tank mechanical agitators 346. In one aspect, an in-tank mechanical agitator 346 may include one or more agitator motors 354 mounted to a top of the at least one mobile LC tank. In other aspects, an in-tank mechanical agitator 346 may include a shaft 356 coupled to the agitator motor and extending vertically downward from the top of the mobile LC tank, and a plurality of blades 358 coupled to the shaft. In yet another aspect, one or more controllers (e.g., controller 390) is / are coupled to one or more in-tank mechanical agitators to control one or more of the agitators; in some instance, control of one or more agitators may be pursuant to an automated agitation schedule.

[0165] One or more in-tank mechanical agitators 346 may include one or more blades configured to mix the contents of tank 420. The one or more blades may be embodied as a plurality of propeller- style blades. In an aspect, the one or more in-tank mechanical agitators 346 may include a single rectangular blade (e.g., a flat, panel shape), screw-type blade, T-type blade, or U-typeblade, configured to agitate the contents of tank 420 by moving the contents at least partially along an axial direction of shaft 356. One or more agitator motors 354 may receive power from any suitable source, including one or more mobile generators 324, one or more batteries, one or more fuel cells, one or more capacitors, a public utility grid, or the like.

[0166] One or more controllers 390 may monitor a voltage and / or current drawn by each motor of one or more agitator motors 354. The one or more controllers 390 may determine a status of an LC fire retardant, RTU fire retardant, or any suitable tank contents based at least in part on the current drawn by one or more agitator motors 354. For example, a biopolymer gum may be susceptible to consumption by bacteria. As the gum is broken down by the bacteria, the viscosity of the RTU fire retardant will decrease. One or more controllers 390 may monitor changes or trends in agitator motor current over time (e.g., one or more controllers 390 may measure agitator motor current once every hour, 6 hours, 12 hours, day, week, etc.) and correlate changes in current to changes in viscosity of an RTU fire retardant. Decreases in viscosity over time may indicate that the RTU fire retardant is experiencing binder breakdown, e.g., due to a presence of bacteria that feeds on the gum. One or more controllers 390 may transmit a notification indicating that the RTU fire retardant should be inspected, may not be suitable for use, etc.

[0167] Additionally or alternatively tank 420 may include one or more viscometers configured to measure a viscosity an LC fire retardant or RTU fire retardant. One or more controllers 390 may be communicatively coupled to said viscometers and configured to control the one or more in-tank mechanical agitators 346 based on one or more viscosity measurements taken by the viscometers. For example, one or more controllers 390 may be configured to cease agitation of the contents of tank 420 upon determining that a viscosity of the contents is suitably high (and therefore that the contents are suitably mixed).

[0168] Tank 420 may include one or more sensors such as a refractometer in accordance with the present technology. In an embodiment, a plurality of refractometers may be disposed at varying heights within tank 420 to measure LC fire retardant refractive index at corresponding heights. For example, one or more controllers 390 may be communicatively coupled to three refractometers disposed 1 foot above a bottom of tank 420, halfway between a top of tank 420 and a bottom of tank 420, and 1 foot from a top of tank 420, respectively. One or more controllers 390 may be configured to take readings from each sensor and compare refractive index measurements. If the refractive index measurements between two or more of the sensors differs by more than a threshold amount, that may be an indication that settling of an LC fire retardant has occurred and that one or more in-tank mechanical agitators 346 should be activated to ensure the LC fire retardant is evenly mixed.

[0169] In yet another aspect of the mobile LC tank 420, FIGS. 6 and 7 illustrate that the tank 420 may include a lifting system 340 to facilitate connection of the tank with a transport vehicle (not shown) to move the tank 420. The role of the lifting system 340 in facilitating mobility of the tank 420 with relative ease is significant; without the lifting system 340, one of ordinary skill in the art would readily appreciate that another more significant means (e.g., a wrecker truck, a crane, a large telehandler) would be required to move the tank 420. Instead, the lifting system enables movementand transport of the tank 420 via a conventional tractor truck, which can back up proximate to the tank 420, make hydraulics connections, jack up the tank, and then back underneath the tank as needed to complete any other needed connections between the tractor truck and the tank. Thus, the lifting system 340 significantly simplifies the process of moving the tank 420 (and also saves appreciable expense and time, particularly if the tank is to be moved on multiple occasions).

[0170] In yet another aspect of the mobile LC tank 420, FIG. 6 illustrates that the tank may be a multi-compartment tank including at least one bulkhead 360 to form a plurality of compartments 342A, 342B. As shown in FIG. 10 and 1 1, the multi -compartment tank also may include at least a first feed line 362A coupled a first compartment 342A and a second feed line 362B coupled to a second compartment 342B. More specifically, the multi-compartment tank has a front side 366 proximate to the first compartment and a rear side 368 proximate to the second compartment. The tank further may include a rear drain port 364 disposed on the front side and fluidically coupled to the second compartment 342B (e.g., to facilitate front side access to the second compartment).

[0171] In various implementation examples, the multi -compartment tank 420 shown in FIGS. 6- 11 is configured to separately store within the tank the LC fire retardant and either or both of 1) at least some of the water for the mobile mix plant, or 2) at least some of the RTU fire retardant product. For example, the tank 420 may be configured to store the LC fire retardant in the first compartment 342A, and store water in the second compartment 342B (in which case the water inlet is coupled to the second compartment). In this configuration, the tank 420 further may include a water level sensor 332 and an automated water fill valve 334, communicatively coupled to the water level sensor, to automatically refill the second compartment with additional water as the water is consumed from the second compartment to provide the RTU fire retardant product; in this manner, an essentially constant water head pressure at an outlet 344 of the water tank may be maintained.

[0172] As noted earlier, various types of water sources may be employed to provide water for the mobile mix plant. To this end, in some example implementations, the mix plant may include one or more mobile water pumps 336 coupled to the water inlet and the water source. Examples of water sources include, but are not limited to, a fire hydrant, a municipal water line, a well, a water tower, an external water tank, and / or a surface water source pressurized by gravity or a pump.

[0173] Returning to aspects of the multi-compartment tank 420, in another example, respective compartments of the plurality of compartments of the tank have different sizes. Additionally, a given mobile LC tank (whether single or multi-compartment) may include one or more epoxybased interior coatings (or other equivalent coatings) to reduce or mitigate corrosion. Likewise, in general a given mobile LC tank may include one or more tank level sensors to detect a quantity of contents held in the tank.

[0174] Regarding power for the mobile mix plant, in one example the power source is a power grid, and the power connection is coupled to the power grid. Alternatively or in addition, the power source may include one or more mobile generators 324 (and the mobile mix plant may include one or more of these mobile generators).

[0175] Regarding one or more pumps in or coupled to the mobile mix plant, with reference again to FIGS. 4A and 4B, the loading pump 316 may include an electric centrifugal pump with a horsepower rating in a range of from 10 horsepower to 100 horsepower. The loading pump 3 16 may be configured to pump the RTU fire retardant product through the conduit at a flow rate of at least 200 gallons / minute or, alternatively, in a range of from 200 gallons / minute to 500 gallons / minute. In one example, the loading pump 316 is communicatively coupled to the controller(s) 390 and is responsive to at least one pump control signal output by the controller(s) to control a flow rate of the loading pump.

[0176] In another example, the mobile mix plant may also include one or more non-electric mobile backup pumps 328 (e.g., a gas-powered pump, a diesel-powered pump, a natural gas-powered pump, or a hydrogen-powered pump). Additionally, the mobile mix plant may include a backup loop for one or more mobile backup pump (e g., in case of electric pump failure). To this end, as can be seen in FIG. 4A and 4B, the mobile mix plant may include a backup loop 350 fluidically coupled to the non-electric mobile backup pump 328, the automated proportional mixing valve 310, and the conduit 312. In this example, the mobile mix plant also includes one or more isolation valves 352 coupled to the backup loop and operable to isolate the loading pump 316 from the backup loop.

[0177] In connection with FIG. 4A and 4B, in one example the mobile mix plant may further comprise an internal flow meter 314B coupled to the conduit 312 between the automatic proportional mixing valve 310 and the discharge flow meter 314A. In one aspect, the internal flow meter may include an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter and, more specifically, may include a Coriolis flow meter. In another aspect, the internal flow meter 314B provides for a redundant or alternative measurement to the discharge flow meter 314A. In some instances, the discharge flow meter is the property of, and / or under the purview of, the airtanker base. Notwithstanding, in some example implementations the discharge flow meter may constitute part of the mobile mix plant itself. In yet another aspect, the discharge flow meter is one of a micromotion mass flow meter or a Coriolis flow meter.Method for Mobile Mix Plant Operation

[0178] FIG. 12 is a flowchart of an example method 1200 for operating a mobile mix plant for combining liquid concentrate (LC) fire retardant and water to create a ready -to-use (RTU) fire retardant product.

[0179] Block 1210 includes disposing, in a liquid concentrate (LC) tank, the LC fire retardant. The LC tank may include a plurality of sensors including refractive index sensors, fluid level sensors, density sensors, viscosity sensors, density sensors, pH sensors, flow meters, or other suitable sensors. The aforementioned sensors may be used to monitor one or more of a refractive index of the RTU fire retardant product, a viscosity of the RTU fire retardant product, a density of the RTU fire retardant product, a pH of the RTU fire retardant product, or any suitable parameter. The LC tank may include one or more mechanical agitators attached to a surface of the LC tank. The mechanical agitators may be disposed on a top surface of the LC tank, but any surface is contemplated. The one or more mechanical agitators may be communicatively coupled to acontroller. The controller may receive a plurality of measurements from a corresponding plurality of refractive index sensors disposed in the LC tank, the plurality of measurements indicating a refractive index of an LC fire retardant contained in the tank. The controller may determine that a difference between each measurement of the plurality of measurements exceeds a threshold value. The controller may control at least one of a mechanical agitator or a recirculation pump to mix the LC fire retardant in response to the difference exceeding the threshold.

[0180] The controller may determine a current drawn by a motor mechanically coupled to the mechanical agitator when the mechanical agitator mixes the LC fire retardant. The controller may calculate a viscosity of the LC fire retardant based on the current, and, in response to determining that the viscosity of the LC fire retardant is below a threshold, transmit a notification indicating a status of the LC fire retardant.

[0181] The LC tank may further include a lifting system integrated into the LC tank and configured to lift at least a portion of the LC tank. Block 1210 may further include mechanically coupling a transport vehicle to the portion of the LC tank and transporting the LC tank from a first location to a second location.

[0182] Block 1220 includes fluidically coupling the LC fire retardant with water through an automated proportional mixing valve.

[0183] Block 1230 includes pumping the LC fire retardant through the automated proportional mixing valve and into a conduit to mix the LC fire retardant with water, thereby forming a ready - to-use (RTU) fire retardant product, measuring, by a first sensor, a quality value of the RTU fire retardant product in the conduit; and adjusting, by a controller, the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based at least in part on the quality value. The LC fire retardant may be pumped through the automated proportional mixing valve at a flow rate of at least 200 gallons / minute, between about 200 gallons / minute and about 500 gallons / minute, or any suitable flow rate.

[0184] Block 1240 includes measuring a quality value of the RTU fire retardant product in the conduit.

[0185] Block 1250 includes adjusting the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based at least in part on the quality value. Block 1250 may further include adjusting the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based on an in-line density of the RTU fire retardant product measured by a flow meter. The flow meter may include at least one of a discharge flow meter, a Coriolis flow meter, an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.Components of Liquid Concentrates

[0186] LC fire retardants may include one or more retardant compounds. The retardant compounds may include one or more inorganic compounds, one or more organic compounds, or a combination thereof. Table 1 below illustrates exemplary compounds, any one or more of which may be used,alone or in combination, as a retardant compound in LC fire retardants in accordance with the present technology.

[0187] The retardant compound may be a salt. The salt may be a phosphate salt. Preferably the phosphate salt is a technical grade phosphate with low concentrations of heavy metals. The phosphate salt may include ammonium salts of ortho, pyro, tripoly, or tetrapoly phosphoric acid. The phosphate salt in the LC fire retardant composition may include one or more of the following: ammonium orthophosphates, ammonium pyrophosphates, ammonium polyphosphates having an average chain length of less than 20 phosphorus atoms. For example, the phosphate salt may include at least one of diammonium phosphate (DAP), diammonium orthophosphate (DAP), monoammonium phosphate (MAP), monoammonium orthophosphate (MAP), ammonium polyphosphate (APP).

[0188] Instead of (or in addition to) ammonium salts of ortho, pyro, tripoly, or tetrapoly phosphoric acid, the phosphate salt may include a sodium phosphate salt. The sodium phosphate salt may include sodium salts of mono-, di-, tri-, tetra, and polyphosphates. The sodium phosphate salt in the LC fire retardant may include one or more of the following: monosodium phosphate (MSP), disodium phosphate (DSP), disodium phosphate hydrate, sodium ammonium phosphate (SAP), sodium ammonium phosphate hydrate (SAP-H), sodium tripolyphosphate (STPP), trisodium phosphate (TSP), and mixtures thereof. The disodium phosphate can be anhydrous,substantially free of any hydrate. Alternatively, or in combination with the anhydrous disodium phosphate, the disodium phosphate can be a hydrate, substantially free of any anhydrous. The hydrate may have the formula \!a?HP()4( H2()),, where x is about 1 to about 12. For example, x may be equal to at least one of 2, 7, 8, or 12. The disodium phosphate may contain a mixture of multiple different hydrates X^vHPO ilFhO), , such that when measured, y constitutes an average weighted number of hydrates in the mixture, and thus y is not necessarily a whole number. For example, the average weighted value of r may be about 2.0 to about 12.0, preferably about 1.5 to about 1 1.5, more preferably about 2.5 to about 10.5, and more preferably about 3.5 to about 9.5.

[0189] The sodium ammonium phosphate can be anhydrous, substantially free of any hydrate. Alternatively, or in combination with the anhydrous sodium ammonium phosphate, the sodium ammonium phosphate can be a hydrate. The hydrate may have the formula NaPO4HNH4(H2O)A, where x is about 1 to about 4. For example, x may be equal to at least one of 1, 2, 3, or 4. The disodium phosphate may also contain a mixture of multiple different hydrates NaPCUHNFL^FhO)^, such that when measured, y constitutes an average weighted number of hydrates in the mixture, and thus y is not necessarily a whole number. For example, the average weighted value of y may be about 1.0 to about 4.0, preferably about 1.2 to about 3.9, more preferably about 1.4 to about 3.8, and more preferably about 1.6 to about 3.6. The sodium ammonium phosphate hydrate is preferably sodium ammonium phosphate tetrahydrate (SAP-TH) having the formula NaPO4HNH4(H2O)4.

[0190] Instead of (or in addition to) ammonium salts of ortho, pyro, tripoly, or tetrapoly phosphoric acid and / or sodium phosphate salt(s), the phosphate salt may be a calcium phosphate salt. The calcium phosphate salt may include calcium salts of orthophosphates, di- and monohydrogen phosphates, and / or di- and polyphosphates. The calcium phosphate salt in the LC fire retardant may include one or more of the following: monocalcium phosphate (MCP), dicalcium phosphate (DCP), tricalcium phosphate (TCP), octacalcium phosphate (OCP), dicalcium diphosphate, calcium triphosphate, hydroxyapatite, Apatite, or tetracalcium phosphate (TTCP).

[0191] Instead of (or in addition to) ammonium salts of ortho, pyro, tripoly, or tetrapoly phosphoric acid, sodium phosphate salt(s), and / or calcium phosphate salts, the phosphate salt may be a potassium phosphate salt. The potassium phosphate salt in the LC fire retardant may include one or more of the following: monopotassium phosphate (MKP), dipotassium phosphate, or tripotassium phosphate.

[0192] The phosphate salt of the LC fire retardant may include an ammonium source. The ammonium source may be an ammonium salt. The ammonium source may be an ammonium phosphate salt. For example, when the phosphate salt includes ammonium. The ammonium phosphate salt in the LC fire retardant may include one or more of the following: diammonium phosphate (DAP), diammonium orthophosphate (DAP), monoammonium phosphate (MAP), monoammonium orthophosphate (MAP), ammonium polyphosphate (APP), sodium ammonium phosphate (SAP), or sodium ammonium phosphate hydrate (SAP-H). Instead of (or in addition to) an ammonium phosphate salt, the LC fire retardant may include a non-phosphate ammoniumsource. The non-phosphate ammonium source in the LC fire retardant may include one or more of the following: ammonium chloride, ammonium acetate, ammonium citrate, or ammonium sulfate. The retardant concentrate may contain no ammonium phosphate, but when the retardant concentrate is diluted with water to make the final retardant product, the final retardant product may contain ammonium phosphates due to the exchange of ions in solution. The LC fire retardant may contain a mixture of phosphates.

[0193] In certain embodiments, the mixture of phosphates has a molar ratio of ammoniacal nitrogen to phosphorus (N / P molar ratio) of about 0.4 to about 1 .4, preferably about 0.6 to about 1.3, more preferably about 0.8 to about 1.1. For example, the N / P molar ratio is less than about 1.1, or is about 1. For example, the N / P molar ratio may be below 1.05, below 1.04, below 1.03, below 1.02, below 1.01 , or below 1.00. In another embodiment, the N / P molar ratio is greater than about 1.9, for example about 1.9 to about 3.0, preferably about 2.0 to about 2.9, more preferably about 2.1 to about 2.7. For example, the N / P molar ratio may be above 1.95, above 1.96, above 1.97, above 1.98, above 1.99, or above 2.0. As used herein, “ammoniacal nitrogen,” or “phosphorus,” respectively, when referring to the nitrogen to phosphorus molar ratio (N / P molar ratio) refers to any ammoniacal nitrogen (NH4+) or phosphorus present in the formulation from any of the sources listed in Table 1 . For example, the N / P ratio would not include any nitrogen or phosphorus from a dye not listed in Table 1.

[0194] The liquid concentrate may further include a corrosion inhibitor to reduce or, in some instances, corrosion of various components exposed to the liquid concentrate (e.g., the pipes or tubes of the mixing system 100) and / or the final diluted product (e.g., the dispersal systems used in aircraft or ground vehicles to dispense the final diluted product). The components may be formed from various materials including, but not limited to, brass, iron, aluminum, steel, copper, and magnesium.

[0195] The LC fire retardant and / or final diluted product may further include a corrosion inhibitor. The corrosion inhibitor may include an inhibitor for brass, iron, aluminum, steel, copper, and / or magnesium. The corrosion inhibitor may also include an inhibitor for any of the compounds listed in Table 1. The corrosion inhibitor for magnesium may include any corrosion inhibitors disclosed in Lamaka, S. V., et al. “Comprehensive screening of Mg corrosion inhibitors.” Corrosion Science 128 (2017), hereby incorporated by reference in its entirety. The corrosion inhibitor may include an alkyl (such as an alkyl amine) and / or one or more azoles. The corrosion inhibitor may include COBRATEC 928, Denatonium benzoate, benzoic acid, diammonium phosphate, monoammonium phosphate, Wintrol SB 25Na, or a combination of the above. The corrosion inhibitor may include one or more azoles. The corrosion inhibitor may be a Wintrol® Super Azole Mix (Wintrol® SAM-H90 from Wincom, Inc). The Wintrol® SAM-H90 is designed for aqueous application. Wintrol® SAM-H90 provides corrosion resistance in highly corrosive environments caused by halogens, such chloride. Optionally, Wintrol® SAM-H38Na may be used as the corrosion inhibitor, alone or in combination with Wintrol® SAM-H90. The corrosion inhibitor may include but is not limited to, sodium selenite, sodium stearate, sodium lauryl sulfate, stearic acid, sodium benzoate, sodium fluoride, sodium phosphate, monosodium phosphate (MSP), disodium phosphate (DSP), disodium phosphate hydrate(s) (NazHPO^HzOX, where x is about 1to about 12), trisodium phosphate (TSP), monopotassium phosphate (MKP), dipotassium phosphate (DKP), dipotassium phosphate hydrate(s) (K2HPO4(H2O)r, where x is about 3 to about 6), tripotassium phosphate, tripotassium phosphate hydrate(s) (KiFA H O),. where x is about 3 to about 9), monoammonium phosphate (MAP), diammonium phosphate (DAP), triammonium phosphate, triammonium phosphate hydrate(s), iron pyrophosphate, sodium fumarate dibasic, sodium fumarate, magnesium phosphate, benzotriazole derivatives, sodium salts of benzotriazole and derivatives, aqueous mixtures of benzotriazole and derivatives, benzotriazole-5-carboxcylic acid, benzotriazole, butyl benzotriazole, sodium butyl benzotriazole, tolytriazole derivatives, sodium salts of tolytriazole and derivatives, aqueous mixtures of tolytriazole and derivatives, tetrathydro tolytriazole, tolytriazole, hydrogenated tolyltriazole and mixtures thereof, sodium tolytriazole, sodium tolytriazole (50% solution), 3-hydroxyphenyl-4-phenyl-5-mercapto-l,2,4- triazole (HPMT), 3 -aminophenyl-4-phenyl-5 -mercapto- 1,2,4-triazole (APMT), 3,4-diphenyl-5- mercapto- 1,2,4-triazole (DPMT), 3-cinnamyl-4-phenyl-5-mercapto- 1,2,4-triazole (CPMT), 1,8- napthalaldehydic acid, octadecylphosphonic acid, sodium dodecyl sulfonate (SDBS), Wintrol® BBT-25Na, Wintrol® BBT, Wintrol® THT-T, Wintrol® THT-35PG, Wintrol® THT-50K, Wintrol® SAM-H90, Wintrol SB 25Na, Wintrol® SAM-H38Na, Wintrol® SAM-H40(OS), Wintrol® SAM-B90, berberine, pyrrolidine benzylic, catechin, lysergic acid, carmine, fast green, aniline, vanillin, triethanolamine, low freeze grade triethanolamine (85% TEA and 15% water), N,N,N',N'-Tetrakis(2-hydroxyethyl)ethylenediamine, tris(hydroxymethyl)aminomethane (TRIS), Tris(hydroxymethyl)aminome thane hydrochloride (TRIS-HC1), p-chloroaniline, p-nitroaniline, p- methoxyaniline, p-methylaniline, p-cumate Na, sodium silicate, sodium molybdate, sodium molybdate dihydrate, disodium molbdate, disodium molybdate dihydrate, a biopolymer (such as rhamsan gum, xanthan gum, diutan gum, or welan gum), sodium silicofluoride (SSF), and dimercaptothiadiazole (DMTD), or a combination of the above.

[0196] The final diluted product may be uncolored (i.e., clear, natural colored, or free of colorants), or it may be colored using a colorant. The colorant may be a fugitive colorant, a non-fugitive colorant, or a combination of the two. The final diluted product has a first hue which is a color, i.e., either colorless or a color which blends with the normal vegetation and / or ground in the drop zone. This first hue may be grey or white or a combination of the two. The colorant initially colors the final diluted product to a second hue which contrasts with the hue of the ground vegetation. The colorant may be a fugitive component such as a dye or a dye which is dispersed in a matrix (for example, a fugitive pigment), which fades over time and under ambient field conditions to a colorless or less highly colored hue. The colorant may be a mixture of an organic pigment (e.g., a fluorescent pigment) and inorganic pigment (e.g., iron oxide, titania, and / or titanium dioxide). Preferably the colorant is one that is compatible with the fire retardant salts described herein. The fugitive colorant may fade over time with exposure to sunlight. The fugitive colorant may also be a fast fade fugitive colorant that is designed to last a few hours to a few weeks, for example.

[0197] Several fugitive component dyes and pigments can be used as a colorant. The colorant may be a dye(s) and / or a pigment(s). For example, many water-soluble dyes fade rapidly and there are so-called fluorescent pigments (fluorescent dyes encapsulated in a resin integument or dispersed in a thermoplastic as an emulsion) which are suspended in forest fire retardant compositions andwhich also fade rapidly to provide a fugitive effect. The colorant may be an agricultural, pesticide, or food-grade dye or combinations of such dyes that are red, pink, claret, and / or cerise. Examples of fugitive dyes and pigments include, but are not limited to, C.I. Basic Red I dye, 6BL dye, Basic Violet II dye, C.I. Basic Violet 11 : 1 (tetrachlorozincate), C.I. Basic Red 1 :1, Basic Yellow 40, acid fuchsin, basic fuchsin, new fuchsin, acid red 1, acid red 4, acid red 8, acid red 18, acid red 27, acid red 37, acid red 88, acid red 97, acid red 114, acid red 151, acid red 183, acid red 183, fast red violet IB base, solvent red, Rhodamine B, Rhodamine 6G, Rhodamine 123, Rhodamine 110 chloride, erythrosine B, Basacryl red, Phloxine B, rose Bengal, direct red 80, direct red 80, Sudan red 7B, Congo red, neutral red, Fluorescent Red Mega 480, Fluorescent red 610, Fluorescent red 630, Fluorescent Red Mega 520, Pylaklor Red S-361, Pylaklor Scarlet LX-6364A Pylam Bright Red LX- 1895 Pylam Coral LX- 1801, FD&C Red #3, FD&C Red #4, FD&C Red #40, FD&C Red #4 Lake, D&C Red #33, D&C Red #33 Lake, and encapsulated-dye pigments which are available commercially, e.g., the “AX” series pigments, supplied by Day-Glo Color Corp., Cleveland, Ohio. The dye may be Liquitint 564 (X=564 nm) or Liquitint Agro Pink 564 (1=564 nm) from Milliken & Company (Spartanburg, SC). The colorant may also be an organic pigment such as a fluorescent pigment. The fluorescent pigment may be Day-Glo Aurora pink or another pink, red, orange, or crimson (or a combination of the four) fluorescent pigment dispersion. The fluorescent pigment may be UV sensitive and / or be substantially free of formaldehyde and / or have a Lab color spacing of “L” in a range from about 34 to about 89, “a” in a range from about 18 to about 83, and “b” in a range from about -61 to about 56, based on the International Commission of Illumination LAB color space model.

[0198] The colorant may be a colorant from Greenville Colorants (New Brunswick, NJ) or Milliken & Company (Spartanburg, SC). For example, the colorant is a colorant that is compatible for use with the fire retardant salts described herein, such as colorants used in magnesium chloride dust-control and road-stabilization formulations, or in magnesium chloride de-icing formulations. The colorant may be Elcomine Scarlet NAS, Elcomine Scarlaet NAS EX, or Iron Oxide GC- 1 1 OP from Greenville Colorants. The colorant may be a combination of Liquitint 564 and Iron Oxide GC-110P.

[0199] The colorant of the final diluted product may be a dye or include encapsulated-dye fugitive pigments without ultraviolet absorbers. Compared to water soluble dyes, encapsulated-dye pigments are less likely to permanently stain the normal vegetation and / or ground in the drop zone. The fugitive component is present in an amount which provides a color (second hues) to the final diluted product which contrasts with the color of the vegetation and / or ground in the drop zone (normally green, blue-green and / or brown). Advantageously, the second hue is red, orange or pink. The color of the dye may be red, orange, purple, or pink or any combination of the four. Preferably, the dye is one that is compatible with the fire retardant salts described herein. Alternatively, the final diluted product may be colorless if no colorant is added.

[0200] The colorant may also include a non-fugitive component, i.e., a component which is insoluble in the carrier liquid and which, if colored, does not necessarily fade after aerial application of the final diluted product. The non-fugitive component of the colorant is present in an amount sufficient to improve the aerial visibility of the composition when it is first applied tothe vegetation. However, the non-fugitive component is present in less than an amount which prevents the composition from thereafter fading a neutral color. The colorant may be a combination of the fugitive and non-fugitive components. The non-fugitive component in the final diluted product may be iron oxide (Fe2O3 and / or FeatUQ. The iron oxide may be present in combination with the fugitive colorant described above and titanium dioxide or it may be present alone. The weight of the non-fugitive colorant may contain a minimum of at least 12 grams of the non-fugitive colorant in accordance with Specification 5100-304d (January 7, 2020), which is hereby incorporated by reference in its entirety.

[0201] The weight percent of colorant (e.g., fluorescent pigment), relative to the amount of the retardant compound in the liquid concentrate, is about 0.1% to about 15.0%, preferably about 0.2% to about 12.0%, more preferably about 0.3% to about 10.0%, and more specifically about 0.4% to about 8.0%. For example, the weight percent of colorant, relative to the amount of the retardant compound in the liquid concentrate, is about 0.5% to about 5.0%.

[0202] The liquid concentrate may also include an inorganic pigment. The inorganic pigment may act as a colorant. The inorganic pigment may include but is not limited to Iron Oxide, titanium dioxide, magnesium hydroxide, cobalt blue, cerulean blue, malachite, earth green, raw umber, raw sienna, iron black, or burnt sienna. The Iron Oxide may act as an opacifier. The titanium dioxide may act as a pigment, for example, to provide a white pigment. The titanium dioxide may also act as a photo-responsive material to create opacity by scattering light or by protecting the components of the liquid concentrate from UV degradation.

[0203] The weight percent of inorganic pigment, relative to the amount of the retardant compound in the liquid concentrate, is about 0.02% to about 4.0%, preferably about 0.04% to about 3.5%, more preferably about 0.06% to about 3.0%, and more specifically about 0.08% to about 2.5%. For example, the weight percent of inorganic pigment, relative to the amount of the retardant compound in the liquid concentrate, is about 0.1 % to about 2.0%.

[0204] The weight percent of total colorant, relative to the amount of the retardant compound in the liquid concentrate, is about 0.1% to about 30.0%, preferably about 0.2% to about 28.0%, more preferably about 0.3% to about 25%, and more specifically about 0.4% to about 20.0%. For example, the weight percent of total colorant, relative to the amount of the retardant compound in the liquid concentrate, is about 0.5% to about 18.0%.

[0205] The weight percent of the retardant compound(s) relative to the total weight of the liquid concentrate may be about 5% to about 85%, for example about 20% to about 80%, preferably about 30% to about 75%, and particularly about 35% to about 70%. The weight percent of the retardant compound(s) relative to the total weight of the liquid concentrate may be in a range from about 8% to about 12%.

[0206] The liquid concentrate may be any of the liquid concentrates and / or intermediate liquid concentrates formed from dry concentrates disclosed in the following: U.S. Patent Application No. 16 / 894,231 , filed June 5, 2020; U.S. Patent Application No. 16 / 894,214, filed June 5, 2020; U.S. Patent Application No. 17 / 105,019, filed November 25, 2020; U.S. Patent Application No. 17 / 213,770, filed March 26, 2021; U.S. Patent Application No. 17 / 213,780, filed March 26, 2021;U.S. Patent Application No. 17 / 531,269, filed November 19, 2021; U.S. Patent Application No. 18 / 060,943, filed December 1, 2022; U.S. Patent Application No. 17 / 031,024, filed September 24, 2020; U.S. Patent Application No. 17 / 214,266, filed March 26, 2021 ; U.S. Patent Application No. 17 / 531,295, filed November 19, 2021; U.S. Patent Application No. 18 / 060,941, filed December 1, 2022; U.S. Patent Application No. 17 / 458,002, filed August 26, 2021; U.S. Patent Application No. 17 / 845,569, filed June 21, 2022; U.S. Patent Application No. 18 / 182,198, filed March 10, 2023; U.S. Patent Application No. 18 / 425,075, filed January 29, 2024; U.S. Patent Application No. 17 / 552, 196, filed December 15, 2021 ; U.S. Patent Application No. 17 / 821 ,060, filed August 19, 2022; U.S. Patent Application No. 18 / 060,946, filed December 1, 2022; U.S. Patent Application No. 18 / 299,525, filed April 12, 2023; U.S. Patent Application No. 18 / 404,027, filed January 4, 2024; U.S. Patent Application No. 18 / 404,387, filed January 4, 2024; U.S. Patent Application No. 18 / 990,647, filed December 20, 2024; U.S. Patent Application No. 18 / 061,542, filed December 5, 2022; U.S. Patent Application No. 18 / 450,892, filed August 16, 2023; U.S. Patent Application No. 18 / 602,657, filed March 12, 2024; U.S. Patent Application No. 18 / 908,107, filed October 7, 2024; U.S. Provisional Patent Application No. 62 / 858,640, filed June 7, 2019; U.S. Provisional Patent Application No. 62 / 989,350, filed March 13, 2020; U.S. Provisional Patent Application No. 63 / 024,040, filed May 13, 2020; U.S. Provisional Patent Application No. 63 / 325,876, filed March 31, 2022; U.S. Provisional Patent Application No. 63 / 028,765, filed May 22, 2020; U.S. Provisional Patent Application No. 63 / 140,657, filed January 22, 2021; and / or U.S. Provisional Patent Application No. 63 / 686,448, filed August 23, 2024, all of which are incorporated by reference in their entirety.

[0207] The viscosity of the liquid concentrate may be in the range of about 10 cP to about 10,000 cP, For example, the viscosity of the liquid concentrate may be about 100 cP to about 8000 cP, preferably about 500 cP to about 7000 cP, more preferably about 1000 cP to about 6000 cP, more preferably about 1500 cP to about 5000 cP, and more preferably the viscosity may be about 1750 cP to about 2250 cP at 70 °C. For example, the viscosity of the liquid concentrate may be about 1970 cP to about 2090 cP at 70°C.

[0208] To form the final diluted product and / or RTU fire retardant product, the liquid concentrate may be diluted with water. In other words, the final diluted product includes a first amount of liquid concentrate and a second amount of water. The mixing ratio, which is defined as the ratio of water to liquid concentrate may be about 45: 1 to about 0.2:1 (water: liquid concentrate), preferably about 20: 1 to about 0.5:1, more preferably about 10: 1 to about 0.75: 1, and specifically about 5:1 to about 1 :1. For example, the liquid concentrate, may be diluted at a 2:1 mixing ratio (water: liquid concentrate) to form the final diluted product. As another example, the liquid concentrate, may be diluted at a mixing ratio of 1.895:1 (waterdiquid concentrate) on a weight / weight basis.

[0209] The liquid concentrate may be diluted with water so that the final diluted product has a retardant compound (e.g., salt) weight percent of about 2% to about 70%, preferably about 5% to about 40%, more preferably about 7% to about 30%. For example, the concentration of retardant compound (e.g., salt) in final diluted product is about 8% to about 25%.

[0210] The liquid concentrate may be diluted with water so that the final diluted product has a retardant concentration of about 300 grams to about 900 grams of retardant per gallon of water, preferably about 450 grams to about 800 grams of retardant per gallon of water, more preferably about 500 grams to about 750 grams of retardant per gallon of water.

[0211] The final diluted product is a long-term forest fire retardant with improved aerial visibility for either a direct or indirect attack of a forest fire. The resulting final diluted product may be an opaque reddish suspension that resists settling. The final diluted product may be mixed approximately every 7-10 days to ensure uniform density and homogeneity.

[0212] The final diluted product may be any of the final diluted products disclosed in the following: U.S. Patent Application No. 16 / 894,231, filed June 5, 2020; U.S. Patent Application No. 16 / 894,214, filed June 5, 2020; U.S. Patent Application No. 17 / 105,019, filed November 25, 2020; U.S. Patent Application No. 17 / 213,770, filed March 26, 2021 ; U.S. Patent Application No. 17 / 213,780, filed March 26, 2021; U.S. Patent Application No. 17 / 531,269, filed November 19, 2021; U.S. Patent Application No. 18 / 060,943, filed December 1, 2022; U.S. Patent Application No. 17 / 031,024, filed September 24, 2020; U.S. Patent Application No. 17 / 214,266, filed March 26, 2021; U.S. Patent Application No. 17 / 531,295, filed November 19, 2021; U.S. Patent Application No. 18 / 060,941, filed December 1, 2022; U.S. Patent Application No. 17 / 458,002, filed August 26, 2021; U.S. Patent Application No. 17 / 845,569, filed June 21, 2022; U.S. Patent Application No. 18 / 182,198, filed March 10, 2023; U.S. Patent Application No. 18 / 425,075, filed January 29, 2024; U.S. Patent Application No. 17 / 552,196, filed December 15, 2021; U.S. Patent Application No. 17 / 821 ,060, filed August 19, 2022; U.S. Patent Application No. 18 / 060,946, filed December 1, 2022; U.S. Patent Application No. 18 / 299,525, filed April 12, 2023; U.S. Patent Application No. 18 / 404,027, filed January 4, 2024; U.S. Patent Application No. 18 / 404,387, filed January 4, 2024; U.S. Patent Application No. 18 / 990,647, filed December 20, 2024; U.S. Patent Application No. 18 / 061,542, filed December 5, 2022; U.S. Patent Application No. 18 / 450,892, filed August 16, 2023; U.S. Patent Application No. 18 / 602,657, filed March 12, 2024; U.S. Patent Application No. 18 / 908,107, filed October 7, 2024; U.S. Provisional Patent Application No. 62 / 858,640, filed June 7, 2019; U.S. Provisional Patent Application No. 62 / 989,350, filed March 13, 2020; U.S. Provisional Patent Application No. 63 / 024,040, filed May 13, 2020; U.S. Provisional Patent Application No. 63 / 325,876, filed March 31, 2022; U.S. Provisional Patent Application No. 63 / 028,765, filed May 22, 2020; U.S. Provisional Patent Application No. 63 / 140,657, filed January 22, 2021 ; and / or U.S. Provisional Patent Application No. 63 / 686,448, filed August 23, 2024. Each of the aforementioned applications is incorporated by reference in their entirety for all purposes.

[0213] The viscosity of the final diluted product can be adjusted to accommodate a variety of aircrafts and ground-based vehicles by adjusting the amounts of thickening agent(s) added to the liquid concentrate prior to its dilution or by adjusting the dilution factor of the liquid concentrate. In some versions, the final diluted product may be a medium viscosity long-term retardant. The viscosity of the medium viscosity diluted retardant may be in the range of 300 cP to 800 cP, and more preferably the viscosity may be about 460 cP to about 490 cP at 70°F.

[0214] In one embodiment, the final diluted product has apH of about 4.0 to about 10.0, preferably about 4.5 to about 9.8, more preferably about 5.0 to about 9.5, and more preferably about 5.5 to about 9.0. For example, the pH of the final diluted product may be about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, or any value in between 5.5 and9.0.The freezing temperature of the final diluted product may be in the range of 15°F to 25°F. Once blended with water, the final diluted product may be a homogeneous, stable fluid.Clauses of Exemplary Systems and Methods in Accordance with the Present Technology

[0215] Clause 1. A mobile mix plant for deployment at an airtanker base to provide a ready-to-use (RTU) fire retardant product containing at least one fire retardant salt for loading onto an airtanker, the mobile mix plant comprising: a water inlet for coupling to a water source to provide water for the mix plant; a power connection for coupling to at least one power source for the mobile mix plant; at least one mobile liquid concentrate (LC) tank to hold a liquid concentrate (LC) fire retardant containing the at least one fire retardant salt; an automated proportional mixing valve, fluidically coupled to the water inlet and the at least one mobile LC tank, to mix the water and the LC fire retardant and thereby form the RTU fire retardant product; at least one conduit, fluidically coupled to the automated proportional mixing valve and a discharge flow meter, to carry the RTU fire retardant product from the automated proportional mixing valve; at least one loading pump, fluidically coupled to the at least one conduit, to pump the RTU fire retardant product through the at least one conduit; an in-line sensor, positioned in the at least one conduit between the automated proportional mixing valve and the discharge flow meter so as to be in fluidic contact with the RTU fire retardant product, to measure a quality value of the RTU fire retardant product in the at least one conduit; at least one controller, coupled to the in-line sensor and the automated proportional mixing valve, to automatically adjust at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor; and a containment apparatus to provide a physical boundary around at least a portion of the mobile mix plant including the at least one mobile LC tank.

[0216] Clause 2. The mobile mix plant of clause 1 , wherein the at least one mobile LC tank is configured to agitate the LC fire retardant, when the LC fire retardant is present in the at least one mobile LC tank, without the LC fire retardant being circulated out of and back into the at least one mobile LC tank.

[0217] Clause 3. The mobile mix plant of clause 1 or clause 2, wherein the at least one mobile LC tank includes at least one in-tank mechanical agitator.

[0218] Clause 4. The mobile mix plant of an appropriate preceding clause, wherein the at least one in-tank mechanical agitator includes at least one agitator motor mounted to the at least one mobile LC tank.

[0219] Clause 5. The mobile mix plant of any appropriate preceding clause, wherein the at least one in-tank mechanical agitator further includes: a shaft coupled to the at least one agitator motorand extending from a surface of the at least one mobile LC tank; and at least one blade coupled to the shaft.

[0220] Clause 6. The mobile mix plant of any appropriate preceding clause, wherein the at least one controller is coupled to the at least one in-tank mechanical agitator to control the at least one in-tank mechanical agitator.

[0221] Clause 7. The mobile mix plant of any appropriate preceding clause, wherein the at least one controller is configured to control the at least one in-tank mechanical agitator according to an automated agitation schedule.

[0222] Clause 8. The mobile mix plant of any appropriate preceding clause, wherein the at least one mobile LC tank includes at least one lifting system to facilitate connection of the at least one mobile LC tank with a transport vehicle to move the at least one LC tank.

[0223] Clause 9. The mobile mix plant of any appropriate preceding clause, further comprising at least one mobile water pump coupled to the water inlet and the water source.

[0224] Clause 10. The mobile mix plant of any appropriate preceding clause, wherein the water source to which the water inlet is coupled includes at least one of: a fire hydrant; a municipal water line; a well; a water tower; an external water tank; or a surface water source pressurized by gravity or a pump. 1.

[0225] Clause 11. The mobile mix plant of any of the foregoing clauses, wherein the at least one mobile LC tank includes at least one epoxy-based interior coating to reduce or mitigate corrosion.

[0226] Clause 12. The mobile mix plant of any of the foregoing clauses, wherein the at least one mobile LC tank includes at least one tank level sensor to detect a quantity of contents held in the at least one mobile LC tank.

[0227] Clause 13. The mobile mix plant of any of the foregoing clauses, further comprising at least one recirculation pump, coupled to the at least one mobile LC tank, to recirculate the LC fire retardant.

[0228] Clause 14. The mobile mix plant of any of the foregoing clauses, wherein the at least one power source is a power grid, and wherein the power connection is coupled to the power grid.

[0229] Clause 15. The mobile mix plant of any of the foregoing clauses, wherein the at least one power source includes at least one mobile generator, and wherein the mobile mix plant includes the at least one mobile generator.

[0230] Clause 16. The mobile mix plant of any of the foregoing clauses, wherein the at least one loading pump includes an electric centrifugal pump with a horsepower rating in a range of from 10 horsepower to 100 horsepower.

[0231] Clause 17. The mobile mix plant of any of the foregoing clauses, further comprising at least one non-electric mobile backup pump.

[0232] Clause 18. The mobile mix plant of any appropriate preceding clause, wherein the at least one non-electric mobile backup pump includes at least one of a gas-powered pump, a diesel- powered pump, a natural gas-powered pump, or a hydrogen-powered pump.

[0233] Clause 19. The mobile mix plant of any appropriate preceding clause, further comprising a backup loop fluidically coupled to the non-electric mobile backup pump, the automated proportional mixing valve, and the at least one conduit.

[0234] Clause 20. The mobile mix plant of any appropriate preceding clause, further comprising at least one isolation valve coupled to the backup loop and operable to isolate the at least one loading pump from the backup loop.

[0235] Clause 21 . The mobile mix plant of any of the foregoing clauses, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate of at least 200 gallons / minute.

[0236] Clause 22. The mobile mix plant of any of the foregoing clauses, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate in a range of from 200 gallons / minute to 500 gallons / minute.

[0237] Clause 23. The mobile mix plant of any of the foregoing clauses, wherein: the at least one loading pump is communicatively coupled to the at least one controller and is responsive to at least one pump control signal output by the at least one controller to control a flow rate of the at least one loading pump.

[0238] Clause 24. The mobile mix plant of any of the foregoing clauses, further comprising an internal flow meter coupled to the at least one conduit between the automatic proportional mixing valve and the discharge flow meter.

[0239] Clause 25. The mobile mix plant of any appropriate preceding clause, wherein the internal flow meter includes one of an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.

[0240] Clause 26. The mobile mix plant of any appropriate preceding clause, wherein the internal flow meter includes a Coriolis flow meter.

[0241] Clause 27. The mobile mix plant of any of the foregoing clauses, further comprising the discharge flow meter.

[0242] Clause 28. The mobile mix plant of any appropriate preceding clause, wherein the discharge flow meter is one of a micromotion mass flow meter or a Coriolis flow meter.

[0243] Clause 29. The mobile mix plant of any appropriate preceding clause, wherein: the at least one controller is communicatively coupled to the in-line sensor, the flow meter and the automated proportional mixing valve, to automatically adjust the at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor and an in-line density of the RTU fire retardant product measured by the flow meter.

[0244] Clause 30. The mobile mix plant of any of the foregoing clauses, wherein the quality value of the RTU fire retardant product in the at least one conduit as measured by the in-line sensor includes at least one of: a refractive index of the RTU fire retardant product; a viscosity of theRTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

[0245] Clause 31. The mobile mix plant of any appropriate preceding clause, wherein the in-line sensor includes an in-line refractometer, and wherein the quality value of the RTU fire retardant product in the at least one conduit includes at least the refractive index of the RTU fire retardant product.

[0246] Clause 32. The mobile mix plant of any of the foregoing clauses, further comprising at least one communication interface to communicatively couple the at least one controller to the Internet and to provide wireless data access proximate to the mobile mix plant to facilitate at least one of remote control, wireless updating, or troubleshooting of the mobile mix plant.

[0247] Clause 33. The mobile mix plant of any of the foregoing clauses, wherein: the containment apparatus provides a secondary container for contents stored in the at least one LC tank; and the containment apparatus is configured to contain all of the contents of the largest tank of the at least one LC tank.

[0248] Clause 34. A method of operating a mobile mix plant for combining liquid concentrate (LC) fire retardant and water to create a ready-to-use (RTU) fire retardant product, the method comprising: disposing, in a liquid concentrate (LC) tank, the LC fire retardant; fluidically coupling the LC fire retardant with water through an automated proportional mixing valve; pumping the LC fire retardant through the automated proportional mixing valve and into a conduit to mix the LC fire retardant with water, thereby forming the RTU fire retardant product; measuring, by a first sensor, a quality value of the RTU fire retardant product in the conduit; and adjusting, by a controller, the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based at least in part on the quality value.

[0249] Clause 35. The method of any appropriate preceding clause, wherein the quality value of the RTU fire retardant product comprises at least one of: a refractive index of the RTU fire retardant product; a viscosity of the RTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

[0250] Clause 36. The method of any appropriate preceding clause, further comprising: receiving, by a controller, a plurality of measurements from a corresponding plurality of refractive index sensors disposed in the LC tank, the plurality of measurements indicating a refractive index of an LC fire retardant contained in the tank; determining, by the controller, that a difference between each measurement of the plurality of measurements exceeds a threshold value; and controlling, by the controller, at least one of a mechanical agitator or a recirculation pump to mix the LC fire retardant in response to the difference exceeding the threshold.

[0251] Clause 37. The method of any appropriate preceding clause, further comprising: determining, by the controller, a current drawn by a motor mechanically coupled to the mechanical agitator when the mechanical agitator mixes the LC fire retardant; calculating, by the controller and based on the determined current, a viscosity of the LC fire retardant.

[0252] Clause 38. The method of any appropriate preceding clause, further comprising: in response to determining that the viscosity of the LC fire retardant is below a threshold, transmitting a notification indicating a status of the LC fire retardant.

[0253] Clause 39. The method of any appropriate preceding clause, further comprising: lifting, by a lifting system integrated into the LC tank, at least a portion of the LC tank; mechanically coupling a transport vehicle to the portion of the LC tank; and transporting the LC tank from a first location to a second location.

[0254] Clause 40. The method of any appropriate preceding clause, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate of at least 200 gallons / minute.

[0255] Clause 41 . The method of any appropriate preceding clause, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate between 200 gallons / minute and 500 gallons / minute.

[0256] Clause 42. The method of any appropriate preceding clause, further comprising adjusting the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based on an in-line density of the RTU fire retardant product measured by a flow meter.

[0257] Clause 43. The method of any appropriate preceding clause, wherein the flow meter comprises at least one of a discharge flow meter, a Coriolis flow meter, an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.Conclusion

[0258] While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or confi urations will depend upon the specific application or applications for which the inventive teachings is / are used. Those skilled in the art will recognize or be able to ascertain, using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0259] Also, various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0260] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0261] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0262] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0263] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0264] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to atleast one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0265] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMS1. A mobile mix plant for deployment at an airtanker base to provide a ready -to-use (RTU) fire retardant product containing at least one fire retardant salt for loading onto an airtanker, the mobile mix plant comprising: a water inlet for coupling to a water source to provide water for the mix plant; a power connection for coupling to at least one power source for the mobile mix plant; at least one mobile liquid concentrate (LC) tank to hold a liquid concentrate (LC) fire retardant containing the at least one fire retardant salt; an automated proportional mixing valve, fluidically coupled to the water inlet and the at least one mobile LC tank, to mix the water and the LC fire retardant and thereby form the RTU fire retardant product; at least one conduit, fluidically coupled to the automated proportional mixing valve and a discharge flow meter, to carry the RTU fire retardant product from the automated proportional mixing valve; at least one loading pump, fluidically coupled to the at least one conduit, to pump the RTU fire retardant product through the at least one conduit; an in-line sensor, positioned in the at least one conduit between the automated proportional mixing valve and the discharge flow meter so as to be in fluidic contact with the RTU fire retardant product, to measure a quality value of the RTU fire retardant product in the at least one conduit; at least one controller, coupled to the in-line sensor and the automated proportional mixing valve, to automatically adjust at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor; and a containment apparatus to provide a physical boundary around at least a portion of the mobile mix plant including the at least one mobile LC tank.

2. The mobile mix plant of claim 1, wherein the at least one mobile LC tank is configured to agitate the LC fire retardant, when the LC fire retardant is present in the at least one mobile LC tank, without the LC fire retardant being circulated out of and back into the at least one mobile LC tank.

3. The mobile mix plant of claim 1 or claim 2, wherein the at least one mobile LC tank includes at least one in-tank mechanical agitator.

4. The mobile mix plant of claim 3, wherein the at least one in-tank mechanical agitator includes at least one agitator motor mounted to the at least one mobile LC tank.

5. The mobile mix plant of claim 4, wherein the at least one in-tank mechanical agitator further includes:a shaft coupled to the at least one agitator motor and extending from a surface of the at least one mobile LC tank; and at least one blade coupled to the shaft.

6. The mobile mix plant of any of claim 3 through claim 5, wherein the at least one controller is coupled to the at least one in-tank mechanical agitator to control the at least one intank mechanical agitator.

7. The mobile mix plant of claim 6, wherein the at least one controller is configured to control the at least one in-tank mechanical agitator according to an automated agitation schedule.

8. The mobile mix plant of any of the foregoing claims, wherein the at least one mobile LC tank includes at least one lifting system to facilitate connection of the at least one mobile LC tank with a transport vehicle to move the at least one LC tank.

9. The mobile mix plant of claim 1, further comprising at least one mobile water pump coupled to the water inlet and the water source.

10. The mobile mix plant of claim 9, wherein the water source to which the water inlet is coupled includes at least one of: a fire hydrant; a municipal water line; a well; a water tower; an external water tank; or a surface water source pressurized by gravity or a pump.

11. The mobile mix plant of any of the foregoing claims, wherein the at least one mobile LC tank includes at least one epoxy-based interior coating to reduce or mitigate corrosion.

12. The mobile mix plant of any of the foregoing claims, wherein the at least one mobile LC tank includes at least one tank level sensor to detect a quantity of contents held in the at least one mobile LC tank.

13. The mobile mix plant of any of the foregoing claims, further comprising at least one recirculation pump, coupled to the at least one mobile LC tank, to recirculate the LC fire retardant.

14. The mobile mix plant of any of the foregoing claims, wherein the at least one power source is a power grid, and wherein the power connection is coupled to the power grid.

15. The mobile mix plant of any of the foregoing claims, wherein the at least one power source includes at least one mobile generator, and wherein the mobile mix plant includes the at least one mobile generator.

16. The mobile mix plant of any of the foregoing claims, wherein the at least one loading pump includes an electric centrifugal pump with a horsepower rating in a range of from 10 horsepower to 100 horsepower.

17. The mobile mix plant of any of the foregoing claims, further comprising at least one nonelectric mobile backup pump.

18. The mobile mix plant of claim 17, wherein the at least one non-electric mobile backup pump includes at least one of a gas-powered pump, a diesel-powered pump, a natural gas- powered pump, or a hydrogen-powered pump.

19. The mobile mix plant of any of claim 17 or claim 18, further comprising a backup loop fluidically coupled to the non-electric mobile backup pump, the automated proportional mixing valve, and the at least one conduit.

20. The mobile mix plant of claim 19, further comprising at least one isolation valve coupled to the backup loop and operable to isolate the at least one loading pump from the backup loop.

21. The mobile mix plant of any of the foregoing claims, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate of at least 200 gallons / minute.

22. The mobile mix plant of any of the foregoing claims, wherein the at least one loading pump is configured to pump the RTU fire retardant product through at least one conduit at a flow rate in a range of from 200 gallons / minute to 500 gallons / minute.

23. The mobile mix plant of any of the foregoing claims, wherein: the at least one loading pump is communicatively coupled to the at least one controller and is responsive to at least one pump control signal output by the at least one controller to control a flow rate of the at least one loading pump.

24. The mobile mix plant of any of the foregoing claims, further comprising an internal flow meter coupled to the at least one conduit between the automatic proportional mixing valve and the discharge flow meter.

25. The mobile mix plant of claim 24, wherein the internal flow meter includes one of an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.

26. The mobile mix plant of claim 24, wherein the internal flow meter includes a Coriolis flow meter.

27. The mobile mix plant of any of the foregoing claims, further comprising the discharge flow meter.

28. The mobile mix plant of claim 27, wherein the discharge flow meter is one of a micromotion mass flow meter or a Coriolis flow meter.

29. The mobile mix plant of claim 27 or claim 28, wherein: the at least one controller is communicatively coupled to the in-line sensor, the flow meter and the automated proportional mixing valve, to automatically adjust the at least one flow variable for each of the LC fire retardant and the water via the automated proportional mixing valve, based at least in part on the quality value measured by the in-line sensor and an in-line density of the RTU fire retardant product measured by the flow meter.

30. The mobile mix plant of any of the foregoing claims, wherein the quality value of the RTU fire retardant product in the at least one conduit as measured by the in-line sensor includes at least one of: a refractive index of the RTU fire retardant product; a viscosity of the RTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

31. The mobile mix plant of claim 30, wherein the in-line sensor includes an in-line refractometer, and wherein the quality value of the RTU fire retardant product in the at least one conduit includes at least the refractive index of the RTU fire retardant product.

32. The mobile mix plant of any of the foregoing claims, further comprising at least one communication interface to communicatively couple the at least one controller to the Internet and to provide wireless data access proximate to the mobile mix plant to facilitate at least one of remote control, wireless updating, or troubleshooting of the mobile mix plant.

33. The mobile mix plant of any of the foregoing claims, wherein: the containment apparatus provides a secondary container for contents stored in the at least one LC tank; and the containment apparatus is configured to contain all of the contents of the largest tank of the at least one LC tank.

34. A method of operating a mobile mix plant for combining liquid concentrate (LC) fire retardant and water to create a ready-to-use (RTU) fire retardant product, the method comprising: disposing, in a liquid concentrate (LC) tank, the LC fire retardant;fluidically coupling the LC fire retardant with water through an automated proportional mixing valve; pumping the LC fire retardant through the automated proportional mixing valve and into a conduit to mix the LC fire retardant with water, thereby forming the RTU fire retardant product; measuring, by a first sensor, a quality value of the RTU fire retardant product in the conduit; and adjusting, by a controller, the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based at least in part on the quality value.

35. The method of claim 34, wherein the quality value of the RTU fire retardant product comprises at least one of: a refractive index of the RTU fire retardant product; a viscosity of the RTU fire retardant product; a density of the RTU fire retardant product; or a pH of the RTU fire retardant product.

36. The method of claim 34, further comprising: receiving, by a controller, a plurality of measurements from a corresponding plurality of refractive index sensors disposed in the LC tank, the plurality of measurements indicating a refractive index of an LC fire retardant contained in the tank; determining, by the controller, that a difference between each measurement of the plurality of measurements exceeds a threshold value; and controlling, by the controller, at least one of a mechanical agitator or a recirculation pump to mix the LC fire retardant in response to the difference exceeding the threshold.

37. The method of claim 36, further comprising: determining, by the controller, a current drawn by a motor mechanically coupled to the mechanical agitator when the mechanical agitator mixes the LC fire retardant; calculating, by the controller and based on the determined current, a viscosity of the LC fire retardant.

38. The method of claim 37, further comprising: in response to determining that the viscosity of the LC fire retardant is below a threshold, transmitting a notification indicating a status of the LC fire retardant.

39. The method of claim 34, further comprising: lifting, by a lifting system integrated into the LC tank, at least a portion of the LC tank; mechanically coupling a transport vehicle to the portion of the LC tank; and transporting the LC tank from a first location to a second location.

40. The method of claim 34, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate of at least 200 gallons / minute.

41. The method of claim 34, wherein the LC fire retardant is pumped through the automated proportional mixing valve at a flow rate between 200 gallons / minute and 500 gallons / minute.

42. The method of claim 34, further comprising adjusting the automated proportional mixing valve to alter a flow variable for at least one of the LC fire retardant and the water based on an in-line density of the RTU fire retardant product measured by a flow meter.

43. The method of claim 42, wherein the flow meter comprises at least one of a discharge flow meter, a Coriolis flow meter, an electromagnetic flow meter, a Hall effect flow meter, or a turbine flow meter.