Portable tree sap concentrator

Abstract

A portable apparatus for processing liquids, particularly tree sap, is disclosed. The concentrator utilizes reverse osmosis (RO) to separate water from dissolved solids and contaminants in the tree sap, thereby increasing the concentration of the tree sap and reducing subsequent processing time. The portable apparatus includes a compact, portable case (e.g., less than 20 inches in any dimension or under 1400 cubic inches interior volume) with a removable support plate for easy access, cleaning, and component replacement. An ultrafiltration (UF) assembly is strategically placed to manage pressure and further remove organic materials, bacteria, and viruses, thereby improving concentrated sap storability. The system can incorporate a heating device to increase sap temperature, significantly improving throughput in cold conditions. The apparatus and associated methods provide an efficient and user-friendly solution for small-scale sap concentration, reducing boiling time and improving product quality.

Description

PCT / US25 / 40477 04 August 2025 (04.08.2025)Portable Tree Sap ConcentratorRELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 679,195, filed August 5, 2024, and titled Portable Reverse Osmosis Machine, which is incorporated by reference in its entirety.FIELD OF INVENTION

[0002] The present invention generally relates to the field of filtering liquids with undesirable agents in the liquid. More particularly, it relates to a portable tree sap concentrator.BACKGROUND

[0003] Certain industries, such as the maple syrup industry, use reverse osmosis in “reverse” - to concentrate maple sap, which needs to be concentrated from about 2% concentration to about 66% concentration to make maple syrup. Partial concentration of the maple sap is accomplished by passing the unprocessed maple tree sap through the reverse osmosis machine and retaining the brine while discarding (or using for other purposes) the permeate (generally pure water), thereby increasing the concentration of the maple sap solution and reducing the boiling time of the maple sap. While the maple syrup industry has employed this technology for decades, the apparatuses built for commercial purposes are not suitable for small, maple syrup hobbyists which a) do not harvest enough maple sap to use the commercial equipment (due to required sap flow rates), b) need to accumulate and store concentrated sap before processing the concentrated maple sap with an evaporator, c) are processing sap in harsher (e.g., colder and remote) conditions, and d) need to readily clean and replace components of the machine. SUMMARY OF THE INVENTION

[0004] In an embodiment, a portable tree sap concentrator for processing a tree sap liquid that includes undesirable agents includes a portable case having a plurality of sides, a bottom, and aPCT / US25 / 40477 04 August 2025 (04.08.2025) closable lid, wherein a plurality of fluid coupling connectors disposed in one or more of the plurality of sides; a support plate releasably coupled to the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two plate sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case; a pump mounted to the support plate and fluidly coupled to one of the plurality of fluid coupling connectors; a prefilter assembly mounted to the support plate and fluidly coupled to the pump; an RO filter assembly mounted to the support plate and fluidly coupled to the prefilter assembly and includes a brine flow outlet; and a restrictor valve fluidly coupled to the brine flow outlet. The concentrator can further include a heating device, the heating device fluidly coupled to the pump and capable of raising the temperature of the tree sap liquid more than 10 degrees Fahrenheit. The concentrator can further include a UV filter fluidly coupled to the prefilter assembly and the RO filter assembly. The UV filter can be releasably attached to one of the two opposing plate sides. The case can include a through-wall connector, wherein the through-wall connector is fluidly coupled to the brine flow outlet and to the restrictor valve, and wherein the through wall connector is readily disconnected from the restrictor valve. The concentrator can further include a UF assembly. The UF assembly can be fluidly coupled to the restrictor valve and to a brine flow storage container. The UF assembly can include a 0.5-micron filter media. The UF assembly can be fluidly coupled to the prefilter assembly and the RO filter assembly. The portable case can be less than 20 inches in any dimension.

[0005] In another embodiment, a portable tree sap concentrator for processing a tree sap liquid that includes undesirable agents is disclosed, the including: a portable case; a heating device disposed within the portable case and fluidly connected to a container holding the tree sap liquid,PCT / US25 / 40477 04 August 2025 (04.08.2025) the heating device being capable of heating 40 gallons per hour of the tree sap liquid from about 40 degrees Fahrenheit to about 70 degrees Fahrenheit, but no more than 80 degrees Fahrenheit; a pump disposed within the portable case and fluidly coupled to the heating device; a prefilter assembly disposed within the portable case and fluidly coupled to the pump; an RO filter assembly disposed within the portable case and fluidly coupled to the prefilter assembly, wherein the RO filter assembly includes a brine flow outlet; and a restrictor valve fluidly coupled to the brine flow outlet. The portable case can include a plurality of sides, a bottom, and a closable lid, and having at least one fluid coupling connector disposed in one of the plurality of sides, where the at least one fluid coupling connector is fluidly coupled to the container. The concentrator can further include a UV filter fluidly coupled to the prefilter assembly and the RO filter assembly. The concentrator can further include a support plate releasably coupled to the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case. The heating device, the pump, the prefilter assembly, and the RO filter assembly can be mounted to the support plate and as such, all removable together when the support plate is removed from the portable case. The UV filter can be releasably attached to one of the two opposing plate sides. The concentrator can further include a UF assembly. The UF assembly can be fluidly coupled to the restrictor valve and to a brine flow storage container. The UF assembly can include a 0.5-micron filter media. The UF assembly can be disposed within the portable case. The UF assembly can alternatively or another UF assembly can be fluidly coupled to the prefilter assembly and the RO filter assembly.PCT / US25 / 40477 04 August 2025 (04.08.2025)

[0006] In yet another embodiment, a tree sap concentrator for processing a tree sap liquid that includes undesirable agents includes: a pump fluidly coupled to a source of the tree sap liquid; a prefilter assembly fluidly coupled to the pump; an RO filter assembly fluidly coupled to the prefilter assembly, wherein the RO filter assembly includes a brine flow outlet; a restrictor valve fluidly coupled to the brine flow outlet; and a UF assembly fluidly coupled to the restrictor valve and a storage container for containing the filtered tree sap liquid. The UF assembly can include a 0.5-micron filter media. The tree sap liquid can have a temperature of between 32 degrees Fahrenheit and 45 degrees Fahrenheit. The concentrator can further include a portable case and a support plate, wherein the portable case has a plurality of sides and a bottom and the support plate is releasably coupled to the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case. The concentrator can further include a heating device capable of raising the temperature of the tree sap liquid more than 10 degrees Fahrenheit prior to the tree sap liquid entering the RO filter assembly. The heating device can raise the temperature of the tree sap liquid more than 20 degrees Fahrenheit. The heating device can heat at least 20 gallons per hour of tree sap liquid.

[0007] In yet a further embodiment, a process of preparing a tree sap liquid that includes undesirable agents for processing into syrup is described, the process including: providing a filter assembly with a restrictor valve; pumping the tree sap liquid through the filter assembly; increasing a pressure across the filter assembly; retaining a brine flow that no longer includes undesirable agents. The filter assembly can include a RO filter assembly and a UF assembly and wherein the RO filter assembly and the UF assembly are fluidly coupled by the restrictor valve.PCT / US25 / 40477 04 August 2025 (04.08.2025)The process can further include heating the tree sap liquid prior to entering the RO filter assembly, the heating device heating the tree sap liquid by more than 10 degrees Fahrenheit. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a perspective view of a portable sap concentrator according to an embodiment of the present disclosure;

[0009] FIG 2 is a perspective view of a support plate according to an embodiment of the present disclosure;

[0010] FIG. 3 is a flow diagram of a portable sap concentrator according to an embodiment of the present disclosure;

[0011] FIG. 4 is a flow diagram of another portable sap concentrator according an embodiment of the present disclosure;

[0012] FIG. 5 is a flow diagram of yet another portable sap concentrator according an embodiment of the present disclosure; and

[0013] FIG. 6 is a flow diagram of a further portable sap concentrator according an embodiment of the present disclosure.

[0014] These drawings should not be viewed as limiting in any way to the scope of this disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0015] At a high level, a portable tree sap concentrator (hereinafter, “concentrator”) according to the present invention is capable of processing a liquid having particles, such as sugars, minerals, and undesirable agents (e.g., yeast and bacteria), so as to separate the liquid into a) a substantially all water solution and b) a liquid having a higher concentration of the particles and minerals when compared to the original solution while also being substantially free ofPCT / US25 / 40477 04 August 2025 (04.08.2025) undesirable agents. For example, a 2% maple sap solution can be increased to 4% if the concentrator is operated such that the outputs of the concentrator are 50% permeate and 50% brine. In certain embodiments, the concentrator can include an ultraviolet light device, which can deactivate bacteria and / or yeast in the liquid. In certain embodiments, the concentrator may include a heating device suitable to raise the temperature of the incoming solution prior to separation so as to increase the rate of tree sap liquid processed by the concentrator. In certain embodiments, the concentrator can include one or more reverse osmosis filters, which can increase the throughput of the concentrator. In certain embodiments, the concentrator can include one or more pre-filters to remove larger particles (bark, dirt, bugs, etc.). In certain embodiments, the concentrator can include an ultrafiltration assembly so as to remove organic materials, bacteria, and yeast from the solution prior to or after separation by the reverse osmosis filters.

[0016] FIG. 1 shows a concentrator 100 according to embodiment of the present disclosure. Concentrator 100 can include a case 104, a support plate 108, a pump 112, a prefilter assembly 116, an ultraviolet light (“UV”) filter 120, a reverse osmosis (“RO”) filter assembly 124, a feedsap inlet 126, a permeate outlet 128, a brine outlet 132, and a restrictor valve 136. These elements are connected by tubing with suitable connectors between the various elements, such as press-fit connectors. For tubing, linear low-density polyethylene tubing, can be used to fluidly connect the components of concentrator 100. Tubing and connectors have not been shown in FIG. 1 for clarity.

[0017] Case 104 is designed and configured to a) be readily portable and b) store all or substantially all of the components of concentrator 100. In an exemplary embodiment case 104 is a case that is less than 20 inches in any dimension. In another exemplary embodiment case 104 has an interior volume of less than about 1400 cubic inches. In an embodiment case 104 isPCT / US25 / 40477 04 August 2025 (04.08.2025) plastic. In another exemplary embodiment case 104 is metal. In an embodiment, case 104 includes at least one aperture on the bottom of the case to allow for fluid egress. Multiple apertures may be included in the sides of case 104 to allow for the installation of bulkhead connectors, which allow for readily removable attachment of tubing on each end of the bulkhead connector (thus creating a thru-wall connection for tubing). Additional apertures may be included in case 104 to allow for the mounting and dismounting of support plate 108

[0018] With reference to FIGS 1 and 2, support plate 108 is designed and configured to support many of the components of concentrator 100 and is removably secured to case 104 via apertures 140 means known in the art. In an exemplary embodiment, support plate 108 has two sides 144 (sides 144A and 144B) that extend at slightly obtuse angles from bottom 148. In this embodiment, a user can detach the support plate 108 from case 104 and then remove the support plate (and all the concentrator 100 components attached thereto) thus making accessing the components for cleaning and / or replacement while keeping the size of case 104 to a minimum. Sides 144A and 144B are substantially coextensive with the height of the sides of case 104 and facilitate the attachment of support plate 108 to case 104 and the attachment of one or more components of concentrator 100, For example, as shown in FIG. 1, UV filter 120 is mounted to side 144B (via apertures 140, which also secure side 144B to case 104) while prefilter assembly 116 and RO filter assembly 124 are mounted to plate bottom 148. Plate bottom 148 is typically sized and configured to be coextensive with the bottom of case 104, but is spaced off the bottom of case 104 so as to allow for a gap (not shown). Advantageously, the inclusion of support plate 108 (and the aforementioned gap) within case 104 allows any liquid that may leak from any of the connections of the elements of concentrator 100 to travel to the gap and out the one or more apertures in case 104 rather than maintaining contact with the elements ofPCT / US25 / 40477 04 August 2025 (04.08.2025) concentrator 100. Support plate 108 may include brackets, ties, hook and loop fasteners, or other devices so as to secure components of concentrator 100 to the support plate.

[0019] With reference to FIGS. 1 and 3, pump 112 moves feedsap 158, which is generally held in a bulk container 152, into and through the filters contained therein. In an exemplary embodiment, pump 112 is a self-priming liquid pump suitable for pressuring concentrator 100 to less than 100 psi. Pump 112 includes an inlet and outlet and is fluidly coupled to a bulk container 152. Pump 112 includes a power source that can have an electrical connection terminate at the periphery of case 104, where such electrical connection is designed and configured to support a detachable power cord. In certain embodiments, pump 112 may operate on de power, such that it has electrical leads or connections that allow it to electronically couple to a DC power source, such as a battery, solar panel, wind turbine, water turbine, etc. In certain embodiments, more than one pump 112 may be used to provide adequate pressure. For example, additional pumps 112 may be needed when a plurality of RO filters 124 are part of concentrator 100, or when the horizontal distance from the unprocessed liquid to the concentrator is long, or when the concentrator is a significant distance above the unprocessed liquid, e.g., more than 6 ft, or when necessitated by one or more components of the concentrator, such as if a heating device (discussed with reference to FIG. 4) requires sufficient pressure for activation. In certain embodiments, pump 112 is a diaphragm pump.

[0020] Prefilter assembly 116 is fluidly coupled to pump 112 and is designed to filter out larger (e.g., 5 micron and above) contaminants from the unprocessed liquid. (Note that 5 micron is too large a pore size to filter out most bacteria, viruses, and other undesirable agents). In an embodiment, prefilter assembly 116 is a sediment filter assembly that includes a housing, with a fluid inlet and a fluid outlet, and a sediment filter, which, for example, can be a 5-micron filter.PCT / US25 / 40477 04 August 2025 (04.08.2025)In another embodiment, prefilter assembly 116 is an in-line 5-micron disposable filter. A 5- micron sediment filter is a type of prefilter designed to remove fine particulate matter from a fluid. Its primary function is to trap suspended solids such as rust, dirt, sand, and silt that are 5 micrometers or larger in size. By capturing these tiny particles, the filter protects downstream components like reverse osmosis membranes and UV filters from clogging and damage. This extends the lifespan and maintains the efficiency of concentrator 100, ensuring a steady flow of fluid. Types of prefilter assembly 116 that are suitable for use with concentrator 100 include melt-blown (spun) filters, pleated filters, and string-wound filters.

[0021] Concentrator 100, in certain embodiments, may include UV filter 120 that is fluidly coupled to prefilter assembly 116. UV filter 120 is a disinfection method, rather than a traditional filter, that uses UV-C light to inactivate harmful microorganisms such as bacteria, viruses, and protozoa in the fluid (these items and others described herein are considered “undesirable agents”). Unlike traditional filters that physically trap particles, a UV system works by passing liquid through a chamber containing a UV lamp. The UV-C light damages the DNA and RNA of microbes, rendering them unable to reproduce and effectively neutralizing them. When implemented correctly, this process is chemical-free and does not alter the fluid’s taste, odor, or pH. UV filter 120 is sized (“sized”, meaning the exposure time of the fluid to the UV lamp) so as to adequately process the flow rate of liquid passing being processed by concentrator 100. For example, UV filter 120 can be rated to process a 1 gallon per minute of fluid, which while relatively small, is adequate for the concentrator of the present disclosure which includes several 400 gallon per day RO filters.

[0022] Notably, designers and researchers of RO systems for use with tree sap have denigrated the use of UV filters with maple sap reverse osmosis systems due to research showing thePCT / US25 / 40477 04 August 2025 (04.08.2025) ineffectiveness of the UV filter to deactivate yeast and bacteria. For example, Brian Chabot and Randy Worobo (in the Cornell Maple Bulletin 203 (2007) article titled “Sap Steady UV Unit for Maple Sap”) “tested six different UV units being used by maple producers and found that none of them significantly reduced bacteria and yeast as determined by counting the number of living cells that survived the treatment.” The author pointed to the volume of bacteria and yeast in sap and the volume or thickness of sap being moved through a commercially available UV filter significantly reduced its viability.

[0023] However, these inadequacies are due to inappropriate system design in view of the maple sap flow rates demanded by large maple producers (large maple producers have very large volumes of sap to process and thus require specialized equipment for high-flow rate applications as discussed in the article mentioned in the previous paragraph). In concentrator 100, UV filter 120 is sized and configured to allow for thorough penetration of the UV light through the tree sap. For example, the rated (i.e., at 77 degrees Fahrenheit) flow rate of tree sap through concentrator 100 with one RO filter assembly 124 is 16 gallons per hour, much below the rated capacity of the UV filter, which is 1 gallon per minute (60 gallons per hour). If three RO filters 124 (sized at 400 gallons per day) are employed (generally the maximum amount that a single pump 112 can support, the maximum flow rate (under rated temperature conditions) is about 48 gallons per hour, which is still 20% below the capacity of the UV filter 120. Notably, at typical operating temperatures for hobby sugar makers (~40 degrees Fahrenheit), the flow rate through the three RO filters 124 would be less than half of the flow rate at rated temperature conditions, thus making the UV filter employed with concentrator 100 readily effective.

[0024] The inventor’s own experiments have shown the effectiveness of UV filter 120 when implemented in concentrator 100. In one experiment, maple sap, collected at the end-of-seasonPCT / US25 / 40477 04 August 2025 (04.08.2025) for north-central Vermont (when bacteria and yeast loads are highest) was used. As a control, maple sap (having a 2% sugar concentration) was placed in a sterile container and sealed. In another sterile container, maple sap that had been processed with concentrator 100 was stored and sealed. This container had a sugar content of 3%. In a third sterile container, maple sap that had been processed with a reverse osmosis system that did not include a UV filter was stored and sealed. This maple sap had a sugar content of 4%. All three containers visually contained substantially clear liquid at the start of the test. After 16 days at approximately 50 degrees Fahrenheit, the first and third containers were visibly opaque, with the third container being more opaque than the first. The opaqueness is the result of bacteria and / or yeast growth. Additionally, when unsealed, the first and third container both had a smell characteristic of fouling by bacteria and / or yeast, whereas the second container remained clear and without a noticeable smell. This experiment showed the efficacy of UV filters in small, hobby sized concentrators.

[0025] RO filter assembly 124 is sized and configured to allow for the separation of the liquid tree sap into permeate (water) and brine (concentrated sap). As is known in the art, RO filter assembly 124 can be configured to allow for different processing rates, e.g., 300 gallons per day (gpd), 400 gpd, 500 gpd, 600 gpd, or more for a filter that fits within a 10” RO filter housing. RO filter assembly 124 includes a housing with an inlet and two outlets, and an RO membrane. An RO membrane is a semi-permeable membrane that allows the passage of water molecules but not most of the dissolved salts, organics, bacteria, and pyrogens. The processing capacity of RO filter assembly 124 is determined by the design capacity of the membrane, the pressure exerted by pump 112 (after consideration of other portions of the concentrator, which do impact the available pressure - for example, a clogged prefilter assembly 116 may result in decreased pressure available to force the fluid through the RO filter assembly 124), and, importantly, thePCT / US25 / 40477 04 August 2025 (04.08.2025) temperature of the liquid being processed. In concentrator 100, RO filter assembly 124 is fluidly coupled to UV filter 120 at its inlet (when used, or, alternatively prefilter assembly 116), and has two output fluid flows, a permeate flow 160 and a brine flow 164. In an embodiment, permeate flow 160 and brine flow 164 are independently fluidly coupled to the periphery of case 104, via, for example, tubing (not shown) that is connected to permeate outlet 128 and brine outlet 132 via thru-wall (e.g., bulkhead) connectors 156. The use of connectors 156 allows for variable lengths of tubing to be used to move the permeate flow 160 and brine flow 164 to their respective destinations, e.g. permeate container 168 and brine container 172 (shown in FIG. 3).

[0026] Brine outlet 132 is fluidly coupled to a valve, such as restrictor valve 136. Restrictor valve 136 is designed and configured to allow for reducing the flow of brine through it. Restrictor valve 136 is adjusted by the user to achieve the desired output, e.g., a 50% brine-50% permeate separation. In an embodiment, restrictor valve 136 is a needle valve. In another embodiment, restrictor valve 136 is a ball valve.

[0027] Turning now to FIG. 4, there is shown another embodiment of a portable tree sap concentrator, concentrator 200, according to present disclosure, where like elements to concentrator 100 are identified by the same reference numeral. Concentrator 200, in contrast to concentrator 100, includes a heating device 204, fluidly coupled between container 152 and pump 112, which increases the temperature of the incoming tree sap liquid by up to about 30 degrees Fahrenheit prior to RO filtration. By raising the tree sap liquid temperature, concentrator 200 is able to process more tree sap per hour, in certain embodiments, doubling its output when compared to tree sap processed at ~40 degrees Fahrenheit. This phenomenon is primarily due to the change in water’s viscosity. As water temperature increases, its viscosity decreases (it becomes “thinner”), making it easier for the water molecules to pass through thePCT / US25 / 40477 04 August 2025 (04.08.2025) semi-permeable RO membrane. Conversely, colder water is more viscous, requiring more pressure to push it through the membrane and slowing down the production rate. This is why many RO system manufacturers rate their systems at a standard temperature, typically 77°F (25°C), and provide temperature correction factors to account for different operating conditions.

[0028] In an exemplary embodiment, heater 204 delivers approximately 5,000 BTUs per hour, or roughly 1.5 kilowatts, to achieve a temperature rise 30 degrees Fahrenheit for 40 gallons per hour of tree sap liquid. In another exemplary embodiment, heater 204 delivers approximately 10,000 BTUs per hour, or roughly 3 kilowatts, to achieve a temperature rise of 30 degrees Fahrenheit for 40+ gallons per hour of liquid.

[0029] In certain embodiments, heating device 204 is an immersed resistance type of heater, such that the heating device is placed within container 152 to heat the tree sap liquid prior to processing. This embodiment would have challenges if the user desired to process tree sap liquid as it was being delivered (for example if a tubing system consistently delivered sap to be processed) as there would be limited time for the tree sap liquid to be in contact with the heating device. Another embodiment allows for continuous processing of tree sap by using a heating device 204 with a flow-through design, such as with a tankless water heater, where cold tree sap liquid (between 32 degrees Fahrenheit and 45 degrees Fahrenheit) enters one end of the heating device and passes over / around an internal heating element before exiting at the desired temperature. In this embodiment, heating device 204 includes a control mechanism, such as a thermostat and flow sensor, to ensure a constant output temperature despite potential fluctuations in the input tree sap temperature or flow rate. The heating element of heating device 204 is made of a durable, corrosion-resistant material, such as Inconel or stainless steel, to withstand continuous operation in a wet environment.PCT / US25 / 40477 04 August 2025 (04.08.2025)

[0030] Heating device 204 includes a power source, which may be electrically coupled to pump 112’ s power source and / or UV filter 120’ s power source. In an exemplary embodiment, heating device 204 is a liquid heater capable of raising the temperature of 1 gallon of tree sap liquid per minute over 10 degrees Fahrenheit. In yet another exemplary embodiment, heating device 204 is a liquid heater capable of raising the temperature of 1 gallon of tree sap liquid per minute between about 10 degrees Fahrenheit and 20 degrees Fahrenheit. In a further exemplary embodiment, heating device 140 is a liquid heater capable of raising the temperature of 1 gallon of tree sap liquid per minute between about 20 degrees Fahrenheit and about 30 degrees Fahrenheit. In an exemplary embodiment, heating device 204 is a liquid heater capable of raising the temperature of 1 gallon of tree sap liquid per minute to about 70 degrees Fahrenheit. In certain embodiments, heating device 204 includes or is electronically coupled to a variable speed voltage controller (sometimes referred to as an electric motor rheostat) that allows for adjustments to the power requirements, and thus the heat output, of the heating device. Although heating device 204 is shown in FIG. 4 as fluidly coupled between container 152 and pump 112, heating device 204, in alternative embodiments, can be coupled between the pump and prefilter assembly 116, or between the prefilter assembly and UV filter 120, or between the UV filter and the RO filter assembly 124. In an embodiment, heating device 140 is fluidly coupled after prefilter assembly 116.

[0031] Turning now to FIG. 5, there is shown another exemplary embodiment of a concentrator, concentrator 300, where like elements to the concentrator 100 are identified by the same reference numeral. Concentrator 300 includes an ultrafiltration (UF) assembly 304 fluidly coupled to exit of valve 136. UF assembly 304 is a type of pressure-driven membrane filtration that utilizes a semi-permeable membrane to physically separate contaminants from a liquid. ThePCT / US25 / 40477 04 August 2025 (04.08.2025) core component of UF assembly 304 is the membrane module, which can come in different configurations, such as hollow fiber, spiral-wound, tubular, and plate and frame. The hollow fiber design is one where liquid flows either from the inside-out (in the lumen) or outside-in, passing through thousands of spaghetti-like fibers. The membrane material is typically made from a durable polymer, such as PVDF (polyvinylidene fluoride) or polysulfone, which provides resistance to chemicals and fouling. The operation of UF assembly 304 is a form of size exclusion, meaning that particles larger than the membrane’s pore size are physically blocked and retained on the feed side (the “retentate”), while the purified liquid and smaller dissolved substances pass through to the other side (the “permeate”). To prevent clogging and maintain efficiency, UF assembly can employ either a “cross-flow” or “dead-end” filtration method. In cross-flow, liquid flows tangentially across the membrane surface, continuously sweeping away trapped particles. In dead-end filtration, the liquid is forced directly through the membrane, and a periodic cleaning cycle called “backwashing” is used to flush the accumulated contaminants off the membrane.

[0032] The defining characteristic of an ultrafiltration membrane is its pore size, which determines what it can remove from the liquid. The porosity of UF membranes is much smaller than that of microfiltration (MF) membranes and larger than nanofiltration (NF) and reverse osmosis (RO) membranes. Instead of a simple micron rating, UF membranes are often described by their Molecular Weight Cut-Off (MWCO), which is the molecular weight at which 90% of a specific macromolecule will not pass through the membrane. The typical pore size range for ultrafiltration membranes is 0.01 to 0.5 microns. This range allows UF filters to effectively remove: suspended solids and colloids; bacteria and protozoa (like giardia and cryptosporidium); viruses; high molecular weight organic compounds, and plastics and endotoxins (all of thePCT / US25 / 40477 04 August 2025 (04.08.2025) foregoing being “undesirable agents”). However, because the pores are relatively large compared to nanofiltration and reverse osmosis, UF membranes do not remove dissolved salts, ions, or other low molecular weight molecules and do not require the pressures of RO membranes to operate.

[0033] Ultrafiltration systems operate at relatively low hydrostatic pressures, typically in the range of 5 to 50 psi. This lower pressure is sufficient for UF systems because its membranes have larger pores (0.01 to 0.5 microns) than RO membranes. As UF systems do not remove dissolved salts and ions, these filters do not need to overcome the osmotic pressure that is a major factor in RO systems.

[0034] In concentrator 300, as pump 112 applies hydrostatic pressure to the feedsap 158, forcing it through the various components of concentrator 300, pressure gains across the system as restrictor valve 136 is partially closed. In this embodiment, UF assembly 304 is fluidly coupled after restrictor valve 136 because the fluid pressure before restrictor valve 136 can exceed the safe working pressure of the UF assembly (about 60 psi). (Note that RO filter assembly 124 typically operates best around 80 psi and generally no more than 100 psi - although lower pressures are advertised, at 40 degrees Fahrenheit, more pressure is required). Placing UF assembly 304 after restrictor valve 136 (or after RO filter assembly 124) also advantageously reduces the amount of liquid that UF assembly 304 needs to process (approximately 50% less), thus enhancing system throughput when the feedsap is relatively cold (~40 degrees Fahrenheit). (As with the RO filter assembly 124, the processing rate of UF assembly 304 is significantly impacted by the temperature of the fluid being processed. One would expect around 30 to 40% drop in processing capacity from the UF assembly’s rated capacity when the feedsap temperature is about 40 degrees Fahrenheit.)PCT / US25 / 40477 04 August 2025 (04.08.2025)

[0035] UF assembly 304 includes a housing with an inlet and an outlet, and a membrane capable of separating larger materials such as colloids, particulates, fats, bacteria, and proteins, while allowing sugars, and other low molecular weight molecules to pass through the membrane (e.g., about .01 to about .05 micron). In an alternative embodiment, UF assembly 304 is fluidly coupled to UV filter 120 and prefilter assembly 116. In another embodiment, UF assembly 304 is fluidly coupled to pump 112 and RO filter assembly 124. In yet another embodiment, UF assembly 304 is fluidly coupled to prefilter assembly 116 and RO filter assembly 124. In yet a further embodiment, UF assembly 304 is fluidly coupled to brine flow 164 coming from RO filter assembly 124. In a preferred design for the UF assembly 304, hollow fibers maximize surface area in a given volume, which helps remove contaminants like suspended solids, turbidity, bacteria, and viruses. Use of UF assembly 304 with tree sap concentrators disclosed herein enhances the storability of concentrated tree sap.

[0036] FIG. 6 shows a concentrator 400 according to an embodiment of the present disclosure, where like elements to concentrators 100, 200, or 300 are identified by the same reference numeral. Concentrator 400 is capable of processing more tree sap than concentrator 300 as the inclusion of heating device 204 decreases the viscosity of the feedsap 158 thus improving the flow rates through RO filter assembly 124 and UF assembly 304. In this embodiment, the inclusion of UV filter 120 may seem unnecessary, however, its purpose is to deactivate bacteria and yeast before it enters RO filter assembly 124, thereby decreasing fouling of the RO membrane. In an embodiment, another UF assembly is used in place of UV filter 120 with a similar effect.

[0037] In operation, an intake tube (not shown) has access to container 152. The intake tube is fluidly coupled to case 104 via an intake bulkhead connector. Inside case 104, tubing fluidlyPCT / US25 / 40477 04 August 2025 (04.08.2025) connects the intake bulkhead connector to pump 112. Fluid is then moved from container 152 through pump 112 and then through prefilter assembly 116, then to UV filter 120, then to RO filter assembly 124, which produces brine flow 164 (at this point the RO filter assembly is effectively being bypassed as there is no pressure in the system). Permeate will not flow from RO filter assembly 124 until restrictor valve 136 is at least partially closed thereby increasing the pressure in concentrator 400. When used to process tree sap, the fluid coming from brine flow 164 is sent through UF assembly 304 and then collected for additional processing and the fluid coming from permeate flow 160, being substantially pure water, may be collected for cleaning or other purposes.

[0038] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”

[0039] Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.PCT / US25 / 40477 04 August 2025 (04.08.2025)

[0040] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

PCT / US25 / 40477 04 August 2025 (04.08.2025)ClaimsWhat is claimed is:

1. A portable tree sap concentrator for processing a tree sap liquid that includes one or more undesirable agents, the concentrator comprising: a portable case having a plurality of sides, a bottom, and a closable lid, and having a plurality of fluid coupling connectors disposed in one or more of the plurality of sides; a support plate releasably coupled to the inside of the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two plate sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case; a pump mounted to the support plate and fluidly coupled to one of the plurality of fluid coupling connectors; a prefilter assembly mounted to the support plate and fluidly coupled to the pump; an RO filter assembly mounted to the support plate and fluidly coupled to the prefilter assembly and includes a brine flow outlet; and a restrictor valve fluidly coupled to the brine flow outlet.

2. The concentrator of claim 1, further including a heating device, the heating device fluidly coupled to the pump and capable of raising the temperature of the tree sap liquid more than 10 degrees Fahrenheit.PCT / US25 / 40477 04 August 2025 (04.08.2025)3. The concentrator of claim 1, further including a UV filter fluidly coupled to the prefilter assembly and the RO filter assembly.

4. The concentrator of claim 3, wherein the UV filter is releasably attached to one of the two opposing plate sides.

5. The concentrator of claim 1, wherein the case includes a through-wall connector, wherein the through-wall connector is releasably fluidly coupled to the brine flow outlet and to the restrictor valve.

6. The concentrator of claim 1, further including a UF assembly.

7. The concentrator of claim 6, wherein the UF assembly is fluidly coupled to the restrictor valve and to a brine flow storage container.

8. The concentrator of claim 7, wherein the UF assembly includes a 0.5-micron filter media.

9. The concentrator of claim 6, wherein the UF assembly is fluidly coupled to the prefilter assembly and the RO filter assembly.

10. The concentrator of claim 1, wherein the portable case is less than 20 inches in any dimension.

11. A portable tree sap concentrator for processing a tree sap liquid that includes undesirable agents, the concentrator comprising: a portable case; a heating device disposed within the portable case and fluidly connected to a container holding the tree sap liquid, the heating device being capable of heating 40 gallons per hour of the tree sap liquid from about 40 degrees Fahrenheit to about 60 degrees Fahrenheit, but no more than 80 degrees Fahrenheit; a pump disposed within the portable case and fluidly coupled to the heating device;PCT / US25 / 40477 04 August 2025 (04.08.2025) a prefilter assembly disposed within the portable case and fluidly coupled to the pump; an RO filter assembly disposed within the portable case and fluidly coupled to the prefilter assembly, wherein the RO filter assembly includes a brine flow outlet; and a restrictor valve fluidly coupled to the brine flow outlet.

12. The concentrator of claims 11, wherein the portable case has a plurality of sides, a bottom, and a closable lid, and having at least one fluid coupling connector disposed in one of the plurality of sides, where the at least one fluid coupling connector is fluidly coupled to the container.

13. The concentrator of claim 11, further including a variable power supply electronically coupled to the heating device for controlling the heat output.

14. The concentrator of claim 11, wherein the portable case has a plurality of sides and a bottom and the concentrator further includes a support plate releasably coupled to the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case.

15. The concentrator of claim 14, where each of the heating device, the pump, the prefilter assembly, and the RO filter assembly are mounted to the support plate and as such, all removable together when the support plate is removed from the portable case.

16. The concentrator of claim 14, further including a UV filter and wherein the UV filter is releasably attached to one of the two opposing plate sides.PCT / US25 / 40477 04 August 2025 (04.08.2025)17. The concentrator of claim 14, further including a UF assembly.

18. The concentrator of claim 17, wherein the UF assembly is fluidly coupled to the restrictor valve and to a brine flow storage container.

19. The concentrator of claim 18, wherein the UF assembly includes a 0.5-micron filter media.

20. The concentrator of claim 11, further including a UF assembly disposed within the portable case.

21. The concentrator of claim 20, wherein the UF assembly is fluidly coupled to the restrictor valve and to a brine flow storage container.

22. The concentrator of claim 21, wherein the UF assembly includes a 0.5-micron filter media.

23. The concentrator of claim 20, wherein the UF assembly is fluidly coupled to the prefilter assembly and the RO filter assembly.

24. A tree sap concentrator for processing a tree sap liquid that includes undesirable agents, the concentrator comprising: a pump fluidly coupled to a source of the tree sap liquid; a prefilter assembly fluidly coupled to the pump; an RO filter assembly fluidly coupled to the prefilter assembly, wherein the RO filter assembly includes a brine flow outlet; a restrictor valve fluidly coupled to the brine flow outlet; and a UF assembly fluidly coupled to the restrictor valve and a storage container for containing the filtered tree sap liquid.

25. The concentrator of claim 24, wherein the UF assembly includes a 0.5-micron filter media.

26. The concentrator of claim 24, wherein the tree sap liquid has a temperature of between 32 degrees Fahrenheit and 45 degrees Fahrenheit.PCT / US25 / 40477 04 August 2025 (04.08.2025)27. The concentrator of claim 24, further including a heating device capable of raising the temperature of the tree sap liquid more than 10 degrees Fahrenheit prior to the tree sap liquid entering the RO filter assembly.

28. The concentrator of claim 27, wherein the heating device raises the temperature of the tree sap liquid more than 20 degrees Fahrenheit.

29. The concentrator of claim 24, wherein the heating device heats at least 20 gallons per hour of tree sap liquid.

30. The concentrator of claim 24, further including a portable case and a support plate, wherein the portable case has a plurality of sides and a bottom and the support plate is releasably coupled to the portable case, wherein the support plate includes a plate bottom and two opposing plate sides that are substantially orthogonal to the plate bottom, wherein each of the two sides are releasably attached to a respective side of the portable case, and wherein a gap is formed between the plate bottom and the bottom of the portable case.

31. A process of preparing a tree sap liquid that includes undesirable agents for processing into syrup, the process comprising: providing a filter assembly with a restrictor valve; pumping the tree sap liquid through the filter assembly; increasing a pressure across the filter assembly; retaining a brine flow that no longer includes undesirable agents.PCT / US25 / 40477 04 August 2025 (04.08.2025)32. The process according to claim 31, wherein the filter assembly includes a RO filter assembly and a UF assembly and wherein the RO filter assembly and the UF assembly are fluidly coupled by the restrictor valve.

33. The process according to claim 32, wherein the process further includes heating the tree sap liquid prior to entering the RO filter assembly, the heating device heating the tree sap liquid by more than 10 degrees Fahrenheit.

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