METHODS AND COMPOSITIONS FOR SUPPLYING CARBON DIOXIDE.

Abstract

This document provides methods, apparatus and systems for supplying carbon dioxide as a mixture of solid and gaseous carbon dioxide to a destination.

Description

METHODS AND COMPOSITIONS FOR SUPPLYING CARBON DIOXIDE CROSS REFERENCE This application claims priority over U.S. Provisional Patent Application No. 62 / 779,020, filed on December 13, 2018, which is incorporated herein by reference in its entirety. This application is related to U.S. Patent Application No. 15 / 650,524, filed on July 14, 2017, and U.S. Patent Application No. 15 / 659,334, filed on July 25, 2017, which are incorporated herein by reference. BACKGROUND OF THE INVENTION The use of snow nozzles to produce a mixture of gaseous and solid carbon dioxide from liquid carbon dioxide is well known. A snow nozzle is typically used to deliver a relatively large dose of carbon dioxide as solid carbon dioxide, and it is generally not necessary or possible to achieve a precise or reproducible dose of carbon dioxide from the snow nozzle at a desired ratio of gaseous to solid carbon dioxide, especially at low doses and / or under intermittent conditions. SUMMARY OF THE INVENTION In one respect, methods are provided herein. In certain embodiments, a method is provided herein for intermittently supplying a dose of carbon dioxide in solid and gaseous form to a destination comprising (i) transporting liquid carbon dioxide from a liquid carbon dioxide source to an orifice through a first conduit, wherein (a) the first conduit comprises material capable of withstanding the temperature and pressure of the liquid carbon dioxide, and (b) the pressure drop across the orifice and the orifice configuration are such that solid and gaseous carbon dioxide are produced as the carbon dioxide exits the orifice; (ii) transporting the solid and gaseous carbon dioxide through a second conduit, wherein the ratio of the length of the second conduit to the length of the first conduit is at least 1:1; and (iii) directing the carbon dioxide exiting the second conduit to a destination.In certain embodiments, the length, diameter, and material of the first conduit are such that, after a transition period, the liquid carbon dioxide entering the first conduit reaches the orifice as at least 90% liquid carbon dioxide when the ambient temperature is below 30 °C. In certain embodiments, the second conduit has an interior. QQRQnn / LZnZ / E / Yli smooth. In certain embodiments, the first conduit is not insulated. In certain embodiments, the method further comprises directing solid and gaseous carbon dioxide from the end of the second conduit into a third conduit, wherein the third conduit comprises a portion configured to reduce the flow of carbon dioxide through the third conduit sufficiently to cause the solid carbon dioxide to agglomerate before it exits the third conduit through an opening. In certain embodiments, the portion of the third conduit configured to reduce the flow of carbon dioxide is expanded compared to the second conduit. In certain embodiments, the ratio of the length of the third conduit to the length of the second conduit is less than 0.1:1. In certain embodiments, the third conduit has a length of between 0.30 and 3.04 meters.In certain embodiments, the third conduit has an inside diameter of between 2.54 centimeters and 7.62 centimeters. In certain embodiments, the ratio of the length of the second conduit to that of the first conduit is at least 2:1. In certain embodiments, the first conduit is less than 4.57 meters long. In certain embodiments, the first conduit has an inside diameter of between 0.25 and 0.75 inches. In certain embodiments, the first conduit comprises an internal material of braided stainless steel. In certain embodiments, the second conduit is at least 9.14 meters long. In certain embodiments, the second conduit has an inside diameter of between 0.63 and 1.90 centimeters. In certain embodiments, the second conduit comprises an internal material of PTFE.In certain embodiments, the third conduit comprises a rigid material and is operatively connected to a fourth conduit comprising a flexible material. In certain embodiments, the combined length of the third and fourth conduits is between 0.60 and 3.04 meters. In certain embodiments, the first conduit comprises a valve for regulating the flow of carbon dioxide, wherein the method further comprises determining a pressure and temperature between the valve and the orifice, and determining a flow rate for the carbon dioxide based on the temperature and pressure. In certain embodiments, the flow rate is determined by comparing the pressure and temperature with a set of calibration curves for flow rates at a variety of temperatures and pressures. In certain embodiments, the destination of the carbon dioxide is within a mixer.In certain configurations, the mixer is a concrete mixer. In certain configurations, carbon dioxide is directed to a location in the mixer where, when the mixer is mixing a concrete mix, a wave of concrete is released over the mix. In certain configurations, the concrete mixer is a stationary mixer. In certain configurations, the mixer is a portable mixer. In certain configurations, the mixer is a drum on a ready-mix truck. In certain. In certain embodiments, the total heat capacity of the first and / or second conduit is no more than that which would cool to ambient temperature in less than 30 seconds when liquid carbon dioxide flows through the conduit. In certain embodiments, the orifice and are such that solid and gaseous carbon dioxide exit the orifice in a mixture comprising at least 40% solid carbon dioxide.In certain embodiments, the conduits are directed to add carbon dioxide to a concrete mixer, and where the cement is added to the mixer through a cement conduit comprising a first part comprising a rigid channel connected to a second part comprising a flexible sleeve configured to allow a ready-mix truck to move a hopper in the ready-mix towards the sleeve, so that the sleeve falls into the hopper, allowing the cement and other ingredients to fall into a drum of the ready-mix truck through the sleeve, where the third conduit is positioned alongside the first part of the cement conduit and the fourth conduit is positioned to move and direct itself with the second part of the cement conduit.In certain embodiments, the aggregate is added to the mixer through an aggregate channel adjacent to the cement channel, and where the first part of the third conduit is positioned to reduce contact with the aggregate as it exits the aggregate channel. In certain embodiments, the first part of the third conduit extends to the bottom of the first part of the cement channel, and the fourth conduit is joined to the end of the third conduit, extending from the end of the third conduit to the bottom of the rubber liner or near the bottom of the rubber liner when the rubber liner is placed inside the hopper of the ready-mix truck. In certain modalities, the fourth conduit is placed within x cm of the center of the rubber sleeve, on average, when x = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80 or 90 cm when the rubber sleeve is placed to load concrete materials into the drum of the premix truck. In another aspect, devices are provided herein. In certain embodiments, an apparatus for supplying solid and gaseous carbon dioxide is provided herein, comprising (i) a liquid carbon dioxide source; (ii) a first conduit, wherein the first conduit comprises a proximal end operatively connected to the liquid carbon dioxide source and a distal end operatively connected to an orifice, wherein the first conduit is configured to convey liquid carbon dioxide under pressure to the orifice, and wherein the orifice is open to atmospheric pressure, or close to atmospheric pressure, and is configured to convert the liquid carbon dioxide into a mixture of solid and gaseous carbon dioxide as it passes through the orifice; (ii) a second conduit operatively connected to the orifice for directing the mixture of gaseous and solid carbon dioxide to a desired destination, wherein the second QQRQnn / L7nz / E / YIAI duct has a smooth interior, and the ratio of the length of the first duct to the length of the second duct is less than 1:1. In certain embodiments, the ratio of the length of the first duct to the length of the second duct is less than 1:2. In certain embodiments, the ratio of the length of the first duct to the length of the second duct is less than 1:5. In certain embodiments, the first duct is less than 6.09 meters long. In certain embodiments, the first duct is less than 4.57 meters long. In certain embodiments, the first duct is less than 3.65 meters long. In certain embodiments, the first duct is less than 1.52 meters long. In certain embodiments, the first duct includes a valve before the orifice for regulating the flow of liquid carbon dioxide.In certain embodiments, the apparatus further comprises a first pressure sensor between the valve and the orifice. In certain embodiments, the apparatus further comprises a second pressure sensor between the liquid carbon dioxide source and the valve. In certain embodiments, the apparatus further comprises a third pressure sensor after the orifice. In certain embodiments, the apparatus further comprises a temperature sensor between the valve and the orifice. In certain embodiments, the apparatus further comprises a control system operatively connected to the first pressure sensor and the temperature sensor. In certain embodiments, the controller receives a pressure reading from the first pressure sensor and a temperature reading from the temperature sensor and calculates the carbon dioxide flow rate in the system based on the pressure and temperature.In certain configurations, the controller calculates the flow rate based on a set of calibration curves for the device. In certain configurations, the set of calibration curves is generated using a calibration setup comprising a liquid carbon dioxide source, a first conduit, an orifice, a valve in the first conduit before the orifice, a pressure sensor between the valve and the orifice, and a temperature sensor between the valve and the orifice, wherein the material of the first conduit, its length and diameter, and the material and configuration of the orifice are the same as or similar to those of the device. In certain configurations, the set of calibration curves is generated by determining the carbon dioxide flow rate at a variety of temperatures measured by the temperature sensor and a variety of pressures measured by the pressure sensor.In certain embodiments, the apparatus further comprises a third conduit, operatively connected to the second conduit, wherein the third conduit has a larger internal diameter than the second conduit and wherein the diameter and length of the third conduit are configured to slow the flow of gaseous and solid carbon dioxide and cause agglomeration of the solid carbon dioxide. In certain embodiments, the first conduit is not insulated. QQRQnn / LZnZ / E / YILI In certain embodiments, an apparatus is provided herein for supplying intermittent, low doses of solid and gaseous carbon dioxide, comprising (i) a liquid carbon dioxide source; (ii) a first conduit, wherein the first conduit comprises a proximal end operatively connected to the liquid carbon dioxide source and a distal end operatively connected to an orifice, wherein the first conduit is configured to convey liquid carbon dioxide under pressure to the orifice, and wherein the orifice is open to atmospheric pressure and configured to convert the liquid carbon dioxide into a mixture of solid and gaseous carbon dioxide as it passes through the orifice; (iii) a valve in the conduit between the carbon dioxide source and the orifice, for regulating the flow of liquid carbon dioxide;(iv) a manageable heat source connected to the duct section between the valve and the orifice, and to the orifice, wherein the heat source is configured to heat the duct and the orifice between doses to convert the liquid or solid carbon dioxide into a gas that is vented through the orifice. In certain embodiments, the apparatus further comprises a heat sink operatively connected to the heat source. In certain embodiments, the apparatus further comprises (v) a second duct operatively connected to the orifice for directing the gaseous and solid carbon dioxide mixture to a desired destination. In certain embodiments, the second duct has a smooth interior. In certain embodiments, the ratio of the length of the first duct to the length of the second duct is less than 1:1. In another aspect, systems are provided herein. In certain embodiments, this invention provides a system for the intermittent delivery of solid and gaseous carbon dioxide in doses of less than 132.27 kg, with a time between doses of at least 5 minutes. The system is configured to deliver repeated doses with a solid-to-gas carbon dioxide ratio averaging at least 1:1.5 per dose, in less than 60 seconds per dose, at an ambient temperature of 35°C or lower. In certain embodiments, the system is configured to deliver the repeated doses of carbon dioxide with a coefficient of variation of less than 10%. In certain embodiments, the system is configured to deliver repeated doses of carbon dioxide with a coefficient of variation of less than 5%.In certain embodiments, the system comprises a liquid carbon dioxide source and a conduit from the source to an apparatus configured to convert the liquid carbon dioxide into solid and gaseous carbon dioxide, wherein the conduit does not need to be insulated. In certain embodiments, the conduit is not insulated. In certain embodiments, the system further comprises a second conduit connected to the first. QQRQnn / Lznz / E / YILI apparatus for converting liquid carbon dioxide into solid and gaseous carbon dioxide, wherein the second conduit supplies the solid and gaseous carbon dioxide to a desired location. In certain embodiments, the ratio of the lengths of the first conduit to the second conduit is less than 1:1. INCORPORATION BY REFERENCE All publications, patents, and patent applications mentioned in this descriptive memorandum are incorporated herein by reference to the same extent as if each individual publication, patent, or patent application were indicated individually and specifically as being incorporated by reference. BRIEF DESCRIPTION OF THE FIGURES The novel features of the invention are set forth in detail in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by referring to the following detailed description, which sets forth illustrative embodiments in which the principles of the invention are used, and the accompanying figures, of which: FIGURE 1 shows a direct injection assembly for carbon dioxide that does not require a gas line to keep the assembly free of dry ice between cycles. DETAILED DESCRIPTION OF THE INVENTION The methods and compositions of the present invention provide reproducible dosing of solid and gaseous carbon dioxide, under intermittent conditions and at low doses and short delivery times, without using apparatus and methods that lead to a significant loss of carbon dioxide in the process.The methods and apparatus provided herein may permit very precise dosing, for example, dosing with a coefficient of variation (CV) in repeated doses of less than 10%, less than 8%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%, for example, when dosing repeated batches of less than, for example, 90.71, 68.03, 45.35, 40.82, 36.28, 31.75, 27.21, 22.67, 18.14, 13.60, 9.07, or 4.53 kilograms of carbon dioxide per batch, wherein the carbon dioxide is delivered as a liquid in a first conduit of the system, and exits through an orifice into a second conduit of the system, where it flows as a mixture of solid and gaseous carbon dioxide to a destination. In particular, the methods and compositions of the invention are useful when the doses of carbon dioxide are low and the injection times are short, but it is desired to administer a mixture of solid and gaseous carbon dioxide with a ratio.QQRQnn / L7nz / E / YIAI high solids / gas, even if there is a significant pause between cycles and even at relatively high ambient temperatures. For example, the methods and compositions of the invention can be used to supply a dose of carbon dioxide of at least 2.26, 4.53, 6.80, 9.07, 11.33, 13.60, 15.87, 18.14, 20.41, 22.67, 27.21, 31.75, 36.28, 40.82, 45.35 or 54.43 kilos and / or no more than 4.53, 6.80, 9.07, 11.33, 13.60, 15.87, 18.14, 20.41, 22.67, 27.21, 31.75, 36.28, 40.82, 45.35 or 54.43, such as 2.26-54.43 kg, or 2.26-40.82 kg, or 2.26-27.21 kg, or 2.26-18.14 kg, or 4.53-54.43 kg, or 4.53-40.82 kg, or 4.53-27.21 kg, or 4.53-18.14 kg, intermittently where the average time between doses is at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 40, 50, 60, 80, 100 or 120 minutes, where the dose delivery time is less than 180, 150, 120, 100, 90, 80, 70, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15 or 10 seconds.The ratio of solid / gaseous carbon dioxide supplied to the target may be at least 0.3, 0.32, 0.34, 0.36, 0.38, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48 or 0.49. The reproducibility of the doses between cycles may be such that the coefficient of variation (CV) is less than 20, 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1%. These values ​​can be maintained even at relatively high ambient temperatures, for example, average temperatures above 10, 15, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40 °C. For example, by using the methods and compositions of the invention, it is possible to deliver intermittent doses of carbon dioxide of 2.26–27.21 kg, with an average solids-to-gas ratio of at least 0.4, a delivery time of less than 60 seconds, and at least 2, 4, 5, 7, or 10 minutes between cycles, where the ambient temperature is at least 25°C, with a CV of less than 10%, or even less than 5%, 4%, 3%, 2%, or 1%. Such short delivery times, high solids-to-gas ratios, and high reproducibility, achieved during intermittent low doses, are not possible with the current apparatus without significant waste of carbon dioxide, for example, through continuous venting of gaseous carbon dioxide formed between sections of the pipe.The methods and systems provided herein may allow for accurate, precise, and reproducible dosing of low doses of carbon dioxide, for example, as described above, by converting liquid carbon dioxide into a mixture of solid and gaseous carbon dioxide, without venting the gaseous carbon dioxide into the pipe carrying the liquid carbon dioxide. In current conventional configurations, where carbon dioxide is converted into both solid and gaseous forms, a source of liquid carbon dioxide is connected to an orifice via a conduit, where the orifice is open to the atmosphere. Typically, beyond the orifice, the conduit expands over a relatively short distance, such as one to four meters, to direct the combination of solid and gaseous carbon dioxide to a desired destination. QQRQnn / Lznz / E / YILI In typical current operation, the conduit connecting the liquid carbon dioxide source to the orifice is well insulated. However, in intermittent operation, the conduit will heat up to some extent, depending on the ambient temperature and the time between uses. If the time between uses is long enough, it can become hot enough that when a new burst of liquid carbon dioxide is released into the conduit, the carbon dioxide in the conduit will have converted to gas between cycles, and some of the carbon dioxide released into the conduit will be converted to gaseous carbon dioxide. Often, the first carbon dioxide that emerges from the orifice is only gaseous carbon dioxide.This continues until the liquid carbon dioxide cools the duct to a sufficiently low temperature that it remains in liquid form from its source to the orifice, at which point the desired mixture of solid and gaseous carbon dioxide is supplied. However, the initial portion of the carbon dioxide will be entirely or almost entirely gaseous, and this portion will be relatively large due to the length of the duct extending from the carbon dioxide source to the point of use. For applications such as food manufacturing and similar processes, this initial burst of gaseous carbon dioxide is not a problem, as precise dosing of a solid / gas mixture is not required, and applications are made at intervals that allow little time for the duct to equilibrate with the outside temperature. However, there are applications that require a precise dose of carbon dioxide, delivered at a desired ratio of solid to gaseous carbon dioxide, in low doses and intermittently. This necessitates that the carbon dioxide from the source reaching the orifice be kept in liquid form with a sufficiently small amount of gas formed so as not to significantly affect the dosage. This can be achieved through complex devices such as liquid / gas separators in the pipeline, or a countercurrent mechanism in the snow nozzle itself to keep the carbon dioxide in liquid form before it reaches the orifice (see, for example, U.S. Patent No. 3,667,242). However, such methods require gas venting or reliquefaction, both of which are excessive, inefficient, and costly to implement.This is especially problematic when the distance from the carbon dioxide source to the orifice, which is usually positioned near the desired destination for the snow produced by the snow nozzle, is long, as this provides ample opportunity for the liquid carbon dioxide to convert to gas. There are many applications where the configuration of various devices on-site does not allow for a short distance between the liquid carbon dioxide source, for example, a liquid carbon dioxide tank, and the final destination of the carbon dioxide. For example, in a concrete operation, such as a ready-mix concrete plant or a concrete pouring operation. QQRQnn / Lznz / E / YILI prefabricated, if it is desired to supply a dose of carbon dioxide to the concrete mix in a mixer, the liquid carbon dioxide tank must often be placed at a distance from the supply point, for example, often 15.24 meters or more from the supply point. This document provides methods and compositions that 1) allow the transfer of liquid carbon dioxide from a source, such as a tank, to an orifice where it is converted into solid and gaseous carbon dioxide, while maximizing the percentage of carbon dioxide arriving at the orifice in liquid form, without having to discharge carbon dioxide or use insulated piping; 2) maximize the amount of carbon dioxide that remains solid as it travels from the orifice to its point of use; and 3) allow repeatable and reproducible dosing under a variety of environmental conditions and at low doses of carbon dioxide. In the methods and compositions provided herein, a first conduit, also referred to herein as a transfer conduit or transfer pipe, conveys liquid carbon dioxide from a holding tank to an open orifice at atmospheric or near-atmospheric pressure, configured to convert the liquid carbon dioxide into solid and gaseous carbon dioxide. The first conduit is configured to minimize the amount of gaseous carbon dioxide produced initially in a cycle and during the course of the cycle.Therefore, the length of the first conduit, from the liquid carbon dioxide source to the orifice that produces the mixture of solid and gaseous carbon dioxide, is kept short, preferably as short as possible and / or to a set, calibrated length. The diameter is maintained at a value that allows for a small total volume in the first conduit without being so narrow as to induce a pressure drop sufficient to cause the conversion of liquid carbon dioxide to gas within the conduit. The first conduit is generally not insulated and is made of a material, such as braided stainless steel, that can withstand the temperature and pressure of the liquid carbon dioxide. Because the length is short, the overall heat capacity of the first conduit is low, and the conduit quickly reaches temperature equilibrium with the liquid carbon dioxide upon its initial entry.It will be observed that at very low ambient temperatures, i.e., ambient temperatures below the temperature of the carbon dioxide in the storage tank (which can vary depending on the pressure in the tank), the duct will be at a sufficiently low temperature that virtually no liquid carbon dioxide will convert to gas at the start of the cycle. However, at ambient temperatures above which the carbon dioxide will remain liquid in the duct, some gas formation is inevitable; the amount of gas formed depends on the temperature the duct has reached between cycles and the heat capacity of the duct. Even if the ambient temperature is relatively high (e.g., QQRQnn / Lznz / E / YILI (for example, above 30°C) and the time between cycles is sufficient for the duct to equilibrate with the ambient temperature, only a very short time is required to cool the duct to the temperature of the liquid carbon dioxide flowing through it—for example, less than 10, 8, 7, 6, 5, 4, 3, 2, or 1 second. As the liquid carbon dioxide flows through the duct, more heat will be lost through the duct wall to the outside air (assuming an ambient temperature higher than that of the liquid carbon dioxide) during the flow time, but since the diameter and length of the duct are kept low, the flow is rapid, and relatively little heat is lost as the carbon dioxide flows toward the orifice.Therefore, within a few seconds—for example, 10 seconds, 8 seconds, or 5 seconds—a large proportion of the carbon dioxide remains in liquid form when it reaches the orifice, such as at least 80, 90, 92, 95, 96, 97, 98, or 99%. Because the ratio of solid to gaseous carbon dioxide exiting the orifice is related, at least in part, to the ratio of carbon dioxide that is liquid when it reaches the orifice, a ratio approaching 1:1 solid:gas (by weight) can be achieved within seconds. The first conduit can be any suitable length, but it must be short enough so that a significant amount of gas does not accumulate in the conduit (and it must be removed before the liquid carbon dioxide can reach the orifice). Therefore, the first conduit may have a length of less than 9.14, 7.62, 6.09, 5.18, 4.57, 4.26, 3.96, 3.65, 3.35, 3.04, 2.74, 2.43, 2.13, 1.82, 1.52, 1.21, 0.91, 0.60, 0.30, 0.15, or 0.07 meters, and / or no more than 7.62, 6.09, 5.18, 4.57, 4.26, 3.96, 3.65, 3.35, 3.04, 2.74, 2.43, 2.13, 1.82, 1.52, 1.21, 0.91, 0.60, 0.30, 0.15, 0.07, 0.03 or 0.003 meters, for example, 0.03-7.62 meters, or 0.03-4.57 meters, or 0.03-3.04 meters or 0.30-4.57 meters.Different systems, for example, systems provided to different customers, may have the same length, diameter, and / or material of the first duct, for example, a duct 3.04 meters long, or any other suitable length, so that calibration curves made with the same length and type of duct can be applied to different systems. The inside diameter (Dl) of the first conduit can be any suitable diameter; in general, a smaller diameter is preferred to decrease the mass and travel time to the orifice, but the diameter cannot be so small as to cause a sufficient pressure drop along the length of the conduit for the liquid carbon dioxide to turn into gas. The Dl of the first canal, therefore, may be at least 0.1 [2.54 mm], 0.2 [5.08 mm], 0.3 [7.62 mm], 0.4 [10.1 mm], 0.5 [12.7 mm], 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm] or 1.0 inch [25.4 mm], and / or no more than 0.2 [5.08 mm], 0.3 [7.62 mm], 0.4 [10.1 mm], 0.5 [12.7 mm], 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm], 1.0 inch [25.4 mm] QQRonn / Lznz / E / YiAi 1.5 in [38.1 mm], or 2 in [50.8 mm], such as 0.1–0.8 in [2.54–20.3 mm] or 0.1–0.6 in [2.54–15.2 mm], or 0.2–0.7 in [5.08–17.7 mm] or 0.2–0.6 in [5.08–15.2 mm] or 0.2–0.5 in [5.08–12.7 mm]. The first conduit supplying carbon dioxide to the orifice need not be highly insulated and may, in fact, be made of a material with high thermal conductivity, for example, a thin-walled metal conduit. For example, braided stainless steel tubing, such as that found inside a vacuum-jacketed pipe (but without the vacuum jacket), can be used. The conduit may be rigid or flexible.Because the duct has a short, small diameter, it has a low heat capacity. Therefore, as liquid carbon dioxide is released into the duct, it cools to the temperature of the liquid carbon dioxide very quickly, and the liquid carbon dioxide also passes through its length rapidly. Thus, there is only a short delay from the start of the carbon dioxide supply until the moment the carbon dioxide delivered to the orifice is substantially all liquid carbon dioxide, or at least 80, 85, 90, 95, 96, 97, 98, or 99% of the liquid carbon dioxide. The delay time can be less than 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 second. The delay time will depend on the ambient temperature and the time between cycles. At low ambient temperature and / or short time between cycles, very little or no time will be needed to bring the first conduit to the temperature of liquid carbon dioxide.At a sufficiently low ambient temperature—that is, at or below the temperature of liquid carbon dioxide at the pressure used—virtually no time is needed to equilibrate the first conduit, as it is at a temperature that will not produce any gaseous carbon dioxide as it passes through the liquid carbon dioxide. An example conduit is a 17.15 mm x 3048 mm OA 321SS braided C / W hose with a stainless steel fitting at each end. Typically, the first conduit contains a valve to start and stop the flow of carbon dioxide to the orifice, and the valve is located near the orifice. The section of conduit between the valve and the orifice, and / or the conduit downstream of the orifice, may be subject to icing between cycles. In certain embodiments, a separate gas line is run from the carbon dioxide source to the section of the first conduit between the valve and the orifice, and carbon dioxide gas is sent through this section and the orifice to remove residual liquid carbon dioxide between cycles. In alternative embodiments, no gas conduit is required. In these embodiments, a heat source is positioned such that the conduit section between the valve and the orifice, the orifice itself, and / or a conduit section after the orifice, can be heated sufficiently between cycles that any liquid or solid in these sections and / or the orifice is converted to gas (this would generally only be required when the solenoid is closed). QQRonn / ίζηζ / E / γίΛΐ and the pressure drops, causing the carbon dioxide to fall into the solid / gas phase portion of the phase diagram, resulting in some gas and solid snow that must be converted into gas by the introduction of heat before the next cycle). Furthermore, sufficient suitable material can be included with the heat source so that a heat sink of sufficient capacity is created to sublimate any dry ice that forms between the valve and the orifice between cycles. As the liquid carbon dioxide passes through the valve, the valve temperature approaches the equilibrium temperature of the liquid; by effectively closing the valve, the liquid trapped between the solenoid and the orifice is converted into gas and dry ice in an approximately 1:1 ratio, with the dry ice at, for example, -78.5 °C.This causes slightly more cooling of the valve, but for it to function, there must be sufficient mass in the heat sink to absorb this cooling and still be able to sublimate the dry ice, which has a sublimation enthalpy of 571 kJ / kg (25.2 kJ / mol) before reaching -78.5 °C. An example heat sink can be constructed with a finned design and comprise any suitable material, for example, aluminum. The fins help the heat sink quickly absorb heat from the surroundings, and aluminum can be used because of its rapid heat conduction properties, allowing the heat to move quickly to the valve and sublimate the dry ice. In certain configurations, induction heating can be used. This design allows cycling at short intervals, for example, a minimum interval of 10, 8, 7, 6, 5, 4, 3, 2, or 1 minute, for example, a minimum interval time of approximately 5 minutes.Heating bands can be used in cooler areas and to provide redundancy, such as band reclaim heaters. For example, a first band reclaim heater is wrapped around the heat sink below the liquid valve, and a second band reclaim heater is wrapped around the orifice. In certain configurations, one or more induction heaters can be used. Also in certain configurations, one or more redundant pressure sensors (e.g., two) can be included so that if one fails, the other can take over. In these configurations, the need for gas piping is eliminated, thus reducing the materials used in the system. Furthermore, because a separate source of gaseous carbon dioxide and a source of liquid carbon dioxide are not required, the system can operate with smaller tanks not configured to extract gaseous carbon dioxide, such as mixing tanks or even portable dewars, which are not designed to produce very high gas flow rates—for example, soda fountain tanks. These are readily available for immediate installation in such facilities, eliminating the need to commission custom-built tanks that are small enough for the operation being installed but also equipped with gas piping. QQRonn / Lznz / E / YiAi Figure 1 shows an example of a system that does not require a separate gas pipeline. The CO2 100 piping assembly includes fitting 102 (e.g., 1 / 2 inch [21.34 mm] MNPT, a 1 / 2 inch [13.72 mm] FNPT), valve 104 (e.g., a 1 / 2 inch [21.34 mm] FNPT stainless steel solenoid valve, cryogenic liquid rating), fitting 106 (e.g., 1 / 2 inch [21.34 mm] MNPT x 2 1 / 2 inch [21.34 mm] FNPT tee), nozzle 108 (e.g., stainless steel orifice), heater 110, fitting 112 (e.g., 1 / 2 inch [21.34 mm] Thermowell MNPT), probe 114 (e.g., 1 / 2 inch [21.34 mm] MNPT temperature probe), transmitter 116 (e.g., 1 / 2 inch [21.34 mm] MNPT pressure transmitter and sensor), fitting 118 (for example, MNPT of Ti? inch [21.34 mm] x 4 inch [114.3 mm] nozzle), fitting 120 (for example, FNPT of 1 / 2 inch [21.34 mm] x FNPT of % inch [26.92 mm]), transmitter 122 (for example,temperature transmitter, which can allow the probe to read temperatures below 0 °C) and heat sink 124., The apparatus may contain a variety of sensors, which may include pressure and / or temperature sensors. For example, there may be a first pressure sensor upstream of the valve, indicating the tank pressure; a second pressure sensor downstream of the valve but upstream of the orifice; and / or a third pressure sensor downstream of the orifice. One or more temperature sensors may be used, for example, downstream of the valve but upstream of the orifice, and / or downstream of the orifice. Feedback from one or more of these sensors may be used to, for example, determine the carbon dioxide flow rate. The flow rate may be determined through calculations using one or more of the pressure or temperature values. See, for example, U.S. Patent No. 9,758,437. Additionally or alternatively, the flow rate can be determined by comparison with calibration curves, where such curves can be obtained by measuring the flow, for example, by measuring the change in weight of a tank of liquid carbon dioxide, or any other suitable method, using a conduit and orifice that is similar or identical to those used in operation, at various ambient temperatures and tank pressures. In any case, appropriate pressure and / or temperature measurements in the system can be taken at intervals such as at least every 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 3, 4, or 5 seconds and / or no more than every 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 3, 4, 5, or 6 seconds. The control system can also calculate the amount of carbon dioxide supplied, based on the flow rate and time.In certain modalities, such as for a concrete operation, the control system can be configured to send a signal to a central controller for the concrete operation whenever a certain amount of carbon dioxide flows through the system; the central controller can be configured to. QQRQnn / Lznz / E / YILI, for example, counts the signals and stops the flow of carbon dioxide after a predetermined number of signals has been received, corresponding to the desired dose of carbon dioxide. This is similar to how such controllers can regulate the amount of additive added to a concrete mix. In some systems, the mix is ​​pore-weighted, in which case the system simulates batching to a given weight by mimicking a load cell. Then, when instructed to drop the carbon dioxide into the mixer, the system counts down from the target dosage using the actual carbon dioxide discharge. This involves receiving a signal and providing a feedback voltage based on the weight on the simulated (phantom) scale. Alternatively, the system temperatures and pressures can be matched to one or more appropriate calibration curves, or a series of curves that are interpolated to develop an injection equation. For a given dose, the time to deliver that dose is based on the appropriate injection equation(s). The control system can shut off the carbon dioxide flow after the appropriate time has elapsed. The calibration curve used at any given time may vary depending on the temperature and / or pressure readings at that time. In certain configurations, a temperature sensor is used that provides instantaneous or near-instantaneous feedback on the liquid carbon dioxide temperature, allowing for greater measurement accuracy. It can also quickly detect when only gas is flowing through the system or if the tank is nearly empty. While not strictly theoretical, it is believed that downstream of the orifice, snow formation occurs at temperatures below -70°C, and the solids formation area begins to affect the liquid temperature upstream of the orifice, increasing the flow rate. This temperature sensor flow model can also indicate when a storage tank is out of equilibrium (e.g., after tank filling, when the ambient temperature is lower than the liquid temperature, when the pressure generator in the tank is off, etc.).This model can accommodate very low coefficients of variation (CVs), for example, less than 5%, 3%, 2%, or 1%. It eliminates assumptions about the carbon dioxide tank and the equilibrium between the pressure and temperature of the liquid carbon dioxide. The model reads the tank pressure at the start of injection and calculates the expected temperature of the liquid carbon dioxide based on a boiling curve equation derived from the carbon dioxide phase diagram. The system also takes an initial temperature reading and calculates the transition time, which is the time from when the liquid valve opens until the liquid flow begins. During the transition time, a mixture of gas and liquid carbon dioxide and / or a gas / liquid flow equation is expected; then, a liquid flow equation is used to calculate the flow rate. QQRQnn / Lznz / E / YILI of carbon dioxide. The model uses a linear equation derived from multiple injections (e.g., more than 10, 100, 500, or more than 1000 injections) across a range of tank pressures and is dependent on the upstream pressure. The model also includes a pressure multiplier that calculates the pressure drop from the inlet liquid pressure sensor to the upstream pressure sensor and adjusts the flow rate as the difference between these two sensors is reached. If there is any obstruction in the system piping, the multiplier will adjust the flow rate accordingly. The temperature multiplier reads the temperature sensor reading and compares it to the calculated temperature of the liquid carbon dioxide. As the sensor reads temperatures lower or higher than the calculated value, the temperature multiplier adjusts the flow rate accordingly.Existing systems can be fitted with new pressure sensors, a taller valve housing for quick and easy repairs, and, to increase durability, a new control and hydraulic fitting are placed on the downstream pressure sensor to remove it from the cold, snow-forming region after the borehole. The hydraulic support has been shown to significantly reduce the failure rate of downstream pressure sensors. Carbon dioxide is converted into a mixture of solid and gaseous carbon dioxide at the orifice; the ratio of solid to gas produced at the orifice depends on the proportion of liquid carbon dioxide entering the orifice. If the carbon dioxide entering the orifice is 100% liquid, the ratio of solid to gaseous carbon dioxide in the resulting mixture of solid and gaseous carbon dioxide exiting the orifice can be approximately 50%. The hole can be any suitable diameter, for example, at least 1 / 64 [0.39 mm], 2 / 64 [0.79 mm], 3 / 64 [1.19 mm], 4 / 64 [1.59 mm], 5 / 64 [1.98 mm], 6 / 64 [2.38 mm], or 7 / 64 [2.77 mm] inches and / or no more than 2 / 64 [0.79 mm], 3 / 64 [1.19 mm], 4 / 64 [1.59 mm], 5 / 64 [1.98 mm], 6 / 64 [2.38 mm], 7 / 64 [2.77 mm], 8 / 64 [3.18 mm], 9 / 64 [3.57 mm], 10 / 64 [3.97 mm], 11 / 64 [4.36 mm], or 12 / 64 [4.76 mm] inches, such as approximately 5 / 64 inch [1.98 mm], or approximately 7 / 64 inch [2.77 mm].The orifice length must be sufficient to prevent the passing liquid carbon dioxide from freezing. Additionally, the orifice can be enlarged to prevent clogging. In certain systems, a dual-orifice manifold block is used, allowing one valve to feed two orifices and two discharge pipes. In dual-orifice systems, a given flow of carbon dioxide can be delivered to the destination in a shorter time, and / or flows can be delivered to two different destinations, and / or the flow can be delivered to a single destination at two different points (e.g., two different points in a mixer, such as a concrete mixer), which can allow for more efficient absorption of carbon dioxide at the destination. This can avoid reliability and accuracy problems in certain systems, for example, in a twin-shaft or roller concrete mixer or other systems with very short cycle times. Therefore, a systemA dual-orifice QQRonn / Lznz / E / YiAi system can allow for a higher delivery rate in a given time (for example, up to 1.8 times that of a single-orifice system; due to thermodynamic changes within the system, this does not reach the theoretical 2 times) and a more targeted delivery (to, for example, two different points in a mixer), allowing for, for example, greater absorption efficiency. A dual-orifice system can be manufactured and used in any suitable manner.For example, a steel manifold, such as a rolled steel or stainless steel manifold, can be fully machined to contain one inlet and two outlets with suitable orifices, such as the 7 / 64" [2.77 mm] orifices described herein. The manifold may have connections for two downstream pressure sensors and one connection for the upstream temperature sensor and pressure sensor tee to reduce the system's mass and the contact time between the liquid and metal. The dual injection system calculates the flow rate through both orifices. The dual injection system may also include an additional soft discharge hose (second conduit, as described herein), an additional injection nozzle, an additional downstream pressure sensor with a bracket, and / or two discharge points at the mixer. The mixture of gaseous and solid carbon dioxide is then conveyed from the orifice to its place of use, for example, in the case of a concrete operation, such as a premixing operation or a precasting operation, to a position to supply the mixture to a mixer containing a cement mixture comprising hydraulic cement and water, such as a premix truck drum or a central mixer, by means of a second conduit, also referred to herein as the supply conduit or pipe.The second conduit is configured to supply the solid and gaseous carbon dioxide mixture to its place of use with very little conversion of solid carbon dioxide to gaseous, so that the solid and gaseous carbon dioxide mixture supplied at the point of use is still at a high solid to gas ratio, for example, the proportion of solid carbon dioxide in the mixture can be at least 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48 or 49% of the total. The secondary conduit is typically configured to minimize friction along its length and heat exchange with the ambient atmosphere, while also providing a small overall volume to maximize flow velocity. For example, the secondary conduit might be a smooth-bore duct with a relatively small diameter. Any suitable means can be used to provide a smooth bore for the secondary conduit, such as ensuring that there are no irregularities on the duct's inner surface and no convolutions. A material with a lining, such as polytetrafluoroethylene (PTFE), can be used to maintain a smooth duct bore. QQRQnn / Lznz / E / YILI that there are no substantial irregularities or bends. The thermal mass of the hose is low due to the thin PTFE and the small amount of stainless steel braiding. It can be insulated, for example, with conventional pipe insulation. The conduit should generally be smooth (not contoured) to allow for smooth flow and must be able to withstand low temperatures; that is, dry ice (snow) passing through the hose will be at a temperature of -78°C. The second example conduits are the SmoothFlex series produced by PureFlex, Kentwood, MI. The materials used in the SmoothFlex series and their weight make these good candidates to ensure minimal heating during transit from the orifice to their destination. This maximizes the fraction of solid carbon dioxide since the sublimation rate remains low. The second conduit can be flexible, rigid, or a combination of both.In certain configurations, at least one part may be flexible to allow for easy placement or repositioning. The second conduit can carry the solid-gas carbon dioxide mixture over long distances with minimal solid-to-gas conversion, as the transit time through the conduit is relatively short due to the force generated by the sudden conversion of liquid carbon dioxide into gas and the subsequent expansion of 500 times or more, forcing the gas-solid mixture through the conduit.The inside diameter of the second conduit may have any inside diameter suitable to allow the rapid passage of carbon dioxide, for example, at least 0.1 [2.54 mm], 0.2 [5.08 mm], 0.3 [7.62 mm], 0.4 [10.1 mm], 0.5 [12.7 mm], 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm] or 1.0 inch [25.4 mm], and / or no more than 0.2 [5.08 mm], 0.3 [7.62 mm], 0.4 [10.1 mm], 0.5 [12.7 mm], 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm], 1.0 inch [25.4 mm] 1.5 inches [38.1 mm], or 2 inches [50.8 mm], such as 0.5 inches [12.7 mm], or 0.625 inches [15.8 mm], or 0.750 inches [19.05 mm]. The second conduit may be, for example, at least 1.52, 3.04, 4.57, 6.09, 7.62, 9.14, 10.66, 12.19, 13.71, 15.24, 16.76, 18.28, 19.81, 21.33, 24.38, 27.43, or 30.48 meters long, to reach the final point where carbon dioxide will be used; the length of the second conduit will generally depend on the particular operating configuration in which the carbon dioxide is used.Because the first conduit is generally kept as short as possible, and the second conduit must be of adequate length to reach the point of use, which is often far from the injector orifice, the ratio of the length of the second conduit to that of the first conduit can be at least 0.5, 0.7, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 6, 7, 8, 9, or 10, or greater than 10. For example, the first conduit may not be longer than 3.04 meters, while the second conduit may be at least 6.09, 9.14, 12.19, or 15.24 meters long. The second conduit may be placed inside another conduit, such as a loose plastic hose, to prevent kinking during installation. The second conduit can be further insulated, for example, with pipe insulation, to further minimize heat gain between injections from external sources. In certain configurations, a mixture can be added to the carbon dioxide stream as it is supplied. The mixture can be, for example, liquid. A small amount of liquid mixture can be purged into the discharge pipe after the orifice. The liquid can then quickly freeze into a solid form and be carried along with the carbon dioxide to the mixer. The frozen mixture is carried into the concrete mix along with the carbon dioxide and melts or sublimates into the concrete mix. This method is particularly useful when adding a mixture that has a synergistic effect with the carbon dioxide and / or a mixture that can influence the carbon dioxide mineralization reaction. For example, the TIPA mixture imparts benefits at very small doses, but it is usually added as a liquid cocktail, so the small dose is accompanied by a larger quantity of carrier fluid.If only the active ingredient were added, the small amount could be distributed over the carbon dioxide dose. Mixing systems can be smaller if it is not necessary to add the chemicals in dilute solutions. The second (supply) conduit may be joined to a third conduit, also referred to herein as the directional conduit. The third conduit may have a larger diameter than the second conduit to allow the solid / gaseous carbon dioxide to slow down and mix, so that the solid carbon dioxide agglomerates into larger granules. This is useful, for example, in a concrete operation where carbon dioxide is added to a cement mix so that the granules are large enough to be incorporated into the cement mix before sublimating to a significant degree. The third conduit may have any suitable inside diameter, provided it allows sufficient slowing and agglomeration for the intended use, for example, at least 0.5 [12.7 mm], 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm], 1.0 [25.4 mm], 1.1 [27.9 mm], 1.2 [30.4 mm], 1.3 [33.0 mm], 1.4 [35.5 mm], 1.5 [38.1 mm], 1.6 [40.6 mm], 1.7 [43.1 mm], 1.8 [45.7 mm], 1.9 [48.2 mm], 2 [50.8 mm], 2.1 [53.3mm], 2.2 [55.8mm], 2.3 [58.4 mm], 2.4 [60.9 mm], 2.5 [63.5 mm], 2.6 [66.0 mm], 2.7 [68.5 mm], 2.8 [71.1 mm], 2.9 [73.6 mm], 3 [76.2 mm], 3.2 [81.2 mm], 3.4 [86.3 mm], 3.8 [96.5 mm] or 4 inches [101.6 mm], and / or not more than 0.6 [15.2 mm], 0.7 [17.7 mm], 0.8 [20.3 mm], 0.9 [22.8 mm], 1.0 [25.4 mm], 1.1 [27.9 mm], 1.2 [30.4 mm], 1.3 [33.0 mm], 1.4 [35.5 mm], 1.5 [38.1mm], 1.6 [40.6 mm], 1.7 [43.1 mm], 1.8 [45.7 mm], 1.9 [48.2 mm], 2 [50.8 mm], 2.1 [53.3 mm], 2.2 [55.8 mm], 2.3 [58.4 mm], 2.4 [60.9 mm], 2.5 [63.5 mm], 2.6 [66.0 mm], 2.7 [68.5 mm], 2.8 [71.1 mm], 2.9 [73.6 mm], 3 [76.2 mm], 3.2 [81.2 mm], 3.4 [86.3 mm], 3.8 [96.5 mm] or 4 inches [101.6 mm] or 4.5 inches [114.3 mm], for example, 0.5-4 inches [12.7-101.6 mm], or 0.5-3 inches [12.7-76.2 mm], or 0.5-2.5 inches [12.7-63.5 QQRQnn / Lznz / Ε / ΥΙΛΙ mm], or approximately 2 inches [50.8 mm].The third conduit may be of any length suitable to permit the desired agglomeration without diminishing the carbon dioxide so much, or for so long, that the material adheres to the walls or sublimates to a significant degree, for example, a length of at least 6 [152.4 mm], 8 [203.2 mm], 10 [254.0 mm], 12 [304.8 mm], 14 [355.6 mm], 16 [406.4 mm], 18 [457.2 mm], 20 [508.0 mm], 22 [558.8 mm], 24 [609.6 mm], 28 [711.2 mm], 32 [812.8 mm], 36 [914.4 mm], 40 [1016.0 mm], 44 [1117.6 mm] or 48 inches [1219.2 mm], and / or no more than 8 [203.2 mm], 10 [254.0 mm], 12 [304.8 mm], 14 [355.6 mm], 16 [406.4 mm], 18 [457.2 mm], 20 [508.0 mm], 22 [558.8 mm], 24 [609.6 mm], 28 [711.2 mm], 32 [812.8 mm], 36 [914.4 mm], 40 [1016.0 mm], 44 [1117.6 mm], 48 inches [1219.2 mm], 54 [1371.6 mm], 60 [1524.0 mm], 72 [1828.8 mm], 84 inches [2133.6 mm], for example, 0.60–2.43 meters, or 0.60–1.82 meters, or 0.91-1.82 meters, or 0.91-1.52 meters.The third conduit is generally made of a rigid material strong enough to withstand the conditions in which it is used. For example, in a concrete mixing operation, the third conduit is often placed in the chute through which materials, including aggregates, are channeled into the mixer and come into repeated contact with the moving aggregates. It must be strong and durable enough to withstand repeated contact with the aggregates daily. This can be as much as 20 tons of material per truckload, and 400–500 truckloads per month. Conventional snow nozzle materials will not withstand such an environment. A suitable material is stainless steel, of an appropriate diameter, such as 1 / 8 inch (3.17 to 1 / 2 inch [13.72 mm]). In some cases, it may be desirable to install shielding, for example, in a high-wear location, to increase the thickness, for example, to 1 / 2 inch or even thicker.The third pipe is typically a high-wear component and may require periodic repair, for example, every 3–6 months depending on production. In certain operations, for example, where the third pipe does not move, or rarely moves, or moves only slightly between cycles, the third pipe may be the final pipe in the system. This is the case, for example, in stationary mixers, such as central mixers used in, for example, ready-mix operations. In some operations, such as concrete mixing operations where mix materials are dropped into the drum of a ready-mix truck, the materials are dropped through a channel that terminates in a flexible section. This allows the channel to be placed in the drum's hopper and then removed. In such a situation, a fourth flexible conduit, also called the end conduit herein, can be attached to the third conduit to move with the flexible channel used to drop the concrete materials. The inside diameter of the flexible conduit is such that it fits snugly against the outside diameter of the third conduit. QQRann / Lznz / E / YiAi duct. Any material of suitable flexibility and durability can be used in the fourth duct, such as silicone. In certain configurations, a token system is used as a security measure. For example, a unique key (or "token") is generated at intervals (e.g., monthly) and distributed to the customer if they have no outstanding fees. If there are outstanding fees or other irregularities, the token may be retained. The customer enters the token into the system, for example, via the touchscreen or a web interface screen (which functions similarly to the touchscreen but is displayed on the batch processing computer, making it suitable for installations without a touchscreen). At the end of the time interval (e.g., a month), the system program deactivates the system unless the unique key has been entered. Without the unique key, the system enters inactive mode, and even if an injection start signal is sent to the system, it is ignored.The same can happen if, for example, the system's network connection is lost for a period of time (for example, if a customer disables the network signal in an attempt to run the system without the unique key). Alternatively, external connectors on the enclosure can be used for inputs and outputs, allowing the supplier to disable the system manually or automatically if an attempt is made to tamper with the enclosure. There is no reason for the customer or installer to open the enclosure. In the case of a faulty unit, the customer can be asked to disconnect the external connections, and a replacement unit can be sent to exchange the faulty one. EXAMPLE 1 A ready-mix concrete plant delivers dry batches to its trucks; that is, the dry concrete ingredients are placed in a truck drum with water, and the concrete is mixed in the trucks. It is desired to supply carbon dioxide to the trucks while the concrete is being mixed, where the carbon dioxide is a mixture of solid and gaseous carbon dioxide with a high solid carbon dioxide ratio, for example, at least 40% solid carbon dioxide. There is no space in the batching facility for a liquid carbon dioxide tank to feed the truck via pipeline, so the liquid carbon dioxide tank is located 15.24 meters or more from the final destination. It is desired to administer a dose of 1% carbon dioxide by weight of cement (bwc) to successive batches of concrete in different trucks over the course of a day.The trucks can carry full loads of 7.65 cubic meters of concrete, or partial loads of as little as 0.76 cubic meters. A typical batch of concrete uses 15% cement by weight, and a typical 0.76 cubic meters of concrete weighs 181.43 kilograms. QQRQnn / Lznz / E / YILI 0.76 cubic meters of concrete will contain 272.15 kilograms of cement. Therefore, the lowest dose of carbon dioxide will be 6 kilograms and the highest dose 27.21 kilograms. The time between doses averages at least 10 minutes. Liquid carbon dioxide is piped from a tank to an orifice configured to convert it into solid and gaseous carbon dioxide upon release at atmospheric pressure through a 3.04-meter-long, 3 / 8-inch (9.525 mm) braided stainless steel pipe. After release through the orifice, the solid and gaseous carbon dioxide mixture is conveyed to the drum of a ready-mix truck through a 15.24-meter-long, smooth, insulated, 5 / 8-inch (15.88 mm) inside diameter pipe. This pipe terminates in a 2-inch (60.33 mm) inside diameter, 1 / 4-inch (13.72 mm) thick, 0.60-meter-long stainless steel pipe that is enclosed within the channel conveying the concrete ingredients from their respective storage containers to the truck drum.The stainless steel pipe in turn ends in a flexible section fitted over the steel pipe that moves with the rubber sleeve at the end of the channel that drops into the hopper of the premix truck. The system is calibrated against a calibration system using the same initial pipe length, diameter, and material, tested to determine flow rate under a variety of temperature and pressure conditions. Appropriate pressures and temperatures are taken during system operation for a given batch and fitted to the appropriate calibration curve(s) to determine the flow rate and time required to deliver the desired dose. Carbon dioxide flow ceases when the system has determined that a dose of 1% bwc has been delivered to a truck. Daytime ambient temperatures range from 10 to 25 °C. Each truck remains in the loading area while materials are loaded for a maximum of 90 seconds, and the carbon dioxide supply time is less than 45 seconds. The system administers the appropriate doses to achieve 1% carbon dioxide bwc, at a solid / total carbon dioxide ratio of at least 0.4, over the course of 8 hours, with an average of 5 loads per hour (40 loads in total), with an accuracy of less than 10% of the coefficient of variation. Although preferred embodiments of the present invention have been shown and described herein, it will be evident to those skilled in the art that such embodiments are provided only by way of example. It will be evident to those skilled in the art that various variations, changes, and substitutions may be made without departing from the invention. It will be understood that, in the practice of the invention, several alternatives to the embodiments of the invention described herein may be employed. It is intended that the QQRQnn / Lznz / E / YILI the following claims define the scope of the invention and that the methods and structures within the scope of these claims and their equivalents are covered by them.

Claims

1. A method for intermittently supplying a dose of carbon dioxide in solid and gaseous form to a destination comprising (i) conveying liquid carbon dioxide from a liquid carbon dioxide source to an orifice through a first conduit, wherein (a) the first conduit comprises a material capable of withstanding the temperature and pressure of the liquid carbon dioxide, and (b) the pressure drop across the orifice and the orifice configuration are such that solid and gaseous carbon dioxide are produced as the carbon dioxide exits the orifice; (ii) conveying the solid and gaseous carbon dioxide through a second conduit, wherein the ratio of the length of the second conduit to the length of the first conduit is at least 1:1; and (iii) directing the carbon dioxide exiting the second conduit to a destination.

2. The method of claim 1 further wherein the length, diameter and material of the first conduit are such that, after a transition period, the liquid carbon dioxide entering the first conduit reaches the orifice as at least 90% liquid carbon dioxide when the ambient temperature is below 30°C.

3. The method of claim 1 further wherein the second conduit has a smooth interior.

4. The method of claim 1, wherein the first conduit is not insulated.

5. The method of claim 1, further comprising directing solid and gaseous carbon dioxide from the end of the second conduit into a third conduit, wherein the third conduit comprises a portion configured to decrease the flow of carbon dioxide through the portion of the third conduit sufficiently to cause the solid carbon dioxide to clump together before it exits the third conduit through an opening.

6. The method of claim 5, wherein the portion of the third conduit configured to decrease the carbon dioxide flow is an expanded portion compared to the second conduit. QQRQnn / Lznz / E / YILI 7. The method of claim 5, wherein the ratio of the length of the third conduit to the length of the second conduit is less than 0.1:

1.

8. The method of claim 5, wherein the third conduit has a length between 0.30 and 3.04 meters.

9. The method of claim 5, wherein the third conduit has an inside diameter of between 1 inch [25.4 mm] and 3 inches [76.2 mm], 10. The method of claim 1, wherein the ratio of the length of the second conduit to that of the first conduit is at least 2:

1.

11. The method of claim 1, wherein the first conduit has a length of less than 4.57 meters.

12. The method of claim 1, wherein the first conduit has an inside diameter of between 0.25 [6.35 mm] and 0.75 inches [19.0 mm], 13. The method of claim 1, wherein the first conduit comprises an internal braided stainless steel material.

14. The method of claim 1, wherein the second conduit has a length of at least 9.14 meters.

15. The method of claim 1, wherein the second conduit has an inside diameter of between 0.5 [12.7 mm] and 0.75 inches [19.0 mm], 16. The method of claim 1, wherein the second conduit comprises internal PTFE material.

17. The method of claim 5, wherein the third conduit comprises a rigid material, and is operatively connected to a fourth conduit comprising a flexible material.

18. The method of claim 17, wherein the combined length of the third and fourth ducts is between 0.60 and 3.04 meters. QQRonn / Lznz / E / YiAi 19. The method of claim 1, wherein the first conduit comprises a valve for regulating the flow of carbon dioxide, wherein the method further comprises determining a pressure and a temperature between the valve and the orifice, and determining a flow rate for the carbon dioxide based on the temperature and pressure.

20. The method of claim 19, wherein the flow rate is determined by comparing the pressure and temperature with a set of calibration curves for flow rate at a multiplicity of temperatures and pressures.

21. The method of claim 1, wherein the destination to which the carbon dioxide is directed is within a mixer.

22. The method of claim 21, wherein the mixer is a concrete mixer.

23. The method of claim 22, wherein the carbon dioxide is directed to a location in the mixer where, when the mixer is mixing a concrete mix, a wave of concrete is folded over the concrete mix.

24. The method of claim 22, wherein the concrete mixer is a stationary mixer.

25. The method of claim 22 wherein the mixer is a portable mixer.

26. The method of claim 25, wherein the mixer is a drum from a premix truck.

27. The method of claim 1, wherein the total heat capacity of the first and / or second duct is no more than X.

28. The method of claim 1, wherein the orifice configuration is such that solid and gaseous carbon dioxide exits the orifice in a mixture comprising at least 40% solid carbon dioxide when the carbon dioxide dose through the orifice is less than X weight / mass and the first conduit has reached a temperature of at least Y degrees Celsius before the introduction of liquid carbon dioxide into the first conduit. QQRQnn / L7nz / E / YIAI 29. The method of claim 17, wherein the conduits are directed to adding carbon dioxide to a concrete mixer, and wherein cement is added to the mixer through a cement conduit comprising a first part comprising a rigid channel connected to a second part comprising a flexible sleeve configured to allow a ready-mix truck to move a hopper in the prepared mix toward the sleeve so that the sleeve drops into the hopper, allowing cement and other ingredients to fall into a drum of the ready-mix truck through the sleeve, wherein the third conduit is positioned adjacent to the first part of the cement conduit and the fourth conduit is positioned to move and align itself with the second part of the cement conduit.

30. The method of claim 29, wherein aggregate is added to the mixer through an aggregate channel adjacent to the cement channel, and wherein the first part of the third conduit is positioned to reduce contact with the aggregate as it exits the aggregate channel.

31. The method of claim 29, wherein the first part of the third conduit extends to the bottom of the first part of the cement channel and the fourth conduit is joined to the end of the third conduit, and extends from the end of the third conduit to the bottom of the rubber sleeve or close to the bottom of the rubber sleeve when the rubber sleeve is placed inside the hopper of the premix truck.

32. The method of claim 29, wherein the fourth conduit is placed within x cm of the center of the rubber sleeve, on average, where x = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80 or 90 cm when the rubber sleeve is placed to load concrete materials into the drum of the premix truck.

33. An apparatus for supplying solid and gaseous carbon dioxide comprising (i) a liquid carbon dioxide source; (ii) a first conduit, wherein the first conduit comprises a proximal end operatively connected to the liquid carbon dioxide source, and a distal end operatively connected to an orifice, wherein the first conduit is configured to transport liquid carbon dioxide under pressure to the orifice, and wherein the orifice is open to atmospheric pressure, or close to atmospheric pressure, and is configured to convert the liquid carbon dioxide into a mixture of solid and gaseous carbon dioxide as it passes through the orifice;(iii) a second conduit operatively connected to the orifice for directing the mixture of gaseous and solid carbon dioxide to a desired destination, wherein the second conduit has a smooth interior, and wherein the ratio of the length of the first conduit to the length of the second conduit is less than 1:1.; 34. The apparatus of claim 33 wherein the ratio of the length of the first conduit to the length of the second conduit is less than 1:

2.

35. The apparatus of claim 33 wherein the ratio of the length of the first conduit to the length of the second conduit is less than 1:

5.

36. The apparatus of claim 33 wherein the first conduit is less than 6.09 meters long.

37. The apparatus of claim 33 wherein the first conduit is less than 4.57 meters long.

38. The apparatus of claim 33 wherein the first conduit is less than 3.65 meters long.

39. The apparatus of claim 33 wherein the first conduit is less than 1.52 meters long.

40. The apparatus of claim 33 wherein the first conduit comprises a valve before the orifice for regulating the flow of liquid carbon dioxide.

41. The apparatus of claim 40 further comprising a first pressure sensor between the valve and the orifice.

42. The apparatus of claim 40 further comprising a second pressure sensor between the liquid carbon dioxide source and the valve.

43. The apparatus of claim 40 further comprising a third pressure sensor after the orifice. QQRQnn / Lznz / E / YILI 44. The apparatus of claim 41 further comprising a temperature sensor between the valve and the orifice.

45. The apparatus of claim 44 further comprising a control system operatively connected to the first pressure sensor and the temperature sensor.

46. ​​The apparatus of claim 44 wherein the controller receives a pressure from the first pressure sensor and a temperature from the temperature sensor and calculates the flow rate of carbon dioxide in the system from the pressure and temperature.

47. The apparatus of claim 46 wherein the controller calculates the flow rate based on a set of calibration curves for the apparatus.

48. The apparatus of claim 47 wherein the set of calibration curves is produced with a calibration configuration comprising a liquid carbon dioxide source, a first conduit, an orifice, a valve in the first conduit before the orifice, a pressure sensor between the valve and the orifice, and a temperature sensor between the valve and the orifice, wherein the material of the first conduit, the length and diameter of the first conduit, and the material and configuration of the orifice are the same as or similar to those of the apparatus.

49. The apparatus of claim 48, wherein the set of calibration curves is produced by determining the carbon dioxide flow at a multiplicity of temperatures measured on the temperature sensor and a multiplicity of pressures measured on the pressure sensor.

50. The apparatus of claim 33, further comprising a third conduit operatively connected to the second conduit, wherein the third conduit has a larger inside diameter than the second conduit and wherein the diameter and length of the third conduit are configured to slow the flow of solid and gaseous carbon dioxide and cause agglomeration of the solid carbon dioxide.

51. The apparatus of claim 33 wherein the first conduit is not insulated.

52. A system for intermittently supplying solid and gaseous carbon dioxide in carbon dioxide doses of less than 27.21 kg, with a time between doses of at least 5 minutes, wherein the system is configured to deliver repeated doses with a gaseous to solid carbon dioxide ratio of at least an average of 1:1.5 in each dose, in less than 60 seconds per dose, at an ambient temperature of 35 °C or less. QQRQnn / Lznz / E / YILI 53. The system of claim 52 wherein the system is configured to deliver repeated doses of carbon dioxide with a coefficient of variation of less than 10%.

54. The system of claim 52 wherein the system is configured to deliver repeated doses of carbon dioxide with a coefficient of variation of less than 5%.

55. The system of claim 52 comprising a liquid carbon dioxide source and a conduit from the source to an apparatus configured to convert the liquid carbon dioxide into solid and gaseous carbon dioxide, wherein the conduit is not required to be insulated.

56. The system of claim 55 wherein the conduit is not insulated.

57. The system of claim 55 further comprising a second conduit connected to the apparatus for converting liquid carbon dioxide into solid and gaseous carbon dioxide, wherein the second conduit supplies the solid and gaseous carbon dioxide to a desired location.

58. The system of claim 57, wherein the ratio of the lengths of the first conduit to the second conduit is less than 1:

1.

59. An apparatus for supplying intermittent, low doses of solid and gaseous carbon dioxide, comprising (i) a liquid carbon dioxide source; (ii) a first conduit, wherein the first conduit comprises a proximal end operatively connected to the liquid carbon dioxide source and a distal end operatively connected to an orifice, wherein the first conduit is configured to convey liquid carbon dioxide under pressure to the orifice, and wherein the orifice is open to atmospheric pressure and configured to convert the liquid carbon dioxide into a mixture of solid and gaseous carbon dioxide as it passes through the orifice; (iii) a valve in the conduit between the carbon dioxide source and the orifice, for regulating the flow of liquid carbon dioxide;(iv) a manageable heat source connected to the section of duct between the valve and the orifice, and to the orifice, wherein the heat source is configured to heat the duct and the orifice between the doses to convert liquid or solid carbon dioxide into a gas that is vented through the orifice.; 60. The apparatus of claim 59 further comprising a heat sink operatively connected to the heat source.

61. The apparatus of claim 59 further comprising (v) a second conduit operatively connected to the orifice for directing the mixture of gaseous and solid carbon dioxide to a desired destination 62. The apparatus of claim 61 wherein the second conduit has a smooth interior.

63. The apparatus of claim 61 wherein the ratio of the length of the first conduit to the length of the second conduit is less than 1:1.

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