Method for managing the carbonation curing of hydraulic hardened materials and carbonation curing system for hydraulic hardened materials

Abstract

To provide a carbonation aging management method of a hydraulic hardened body and a carbonation aging system of the hydraulic hardened body, capable of efficiently using CO2 in a carbonation aging tank for carbonation aging of the hydraulic hardened body by reducing the amount of the CO2 leaked from the carbonation aging tank without being used for the carbonation aging of the hydraulic hardened body.SOLUTION: A carbonation curing control method for a hydraulic hardened body includes a filling step of filling a carbonation curing tank for storing a hydraulic hardened body with a carbon dioxide-containing gas having a higher CO2 concentration than air, a curing step of subjecting the hydraulic hardened body to carbonation curing with the carbon dioxide filled in the carbonation curing tank in the filling step, and a discharging step of discharging a gas containing at least carbon dioxide from the inside of the carbonation curing tank to the outside of the carbonation curing tank after the curing step. In the filling step, the curing step, and the discharging step, control is performed under conditions different from each other and according to each step.SELECTED DRAWING: Figure 1

Description

[[Technical Field]]

[0001] The present invention relates to a carbonation curing management method for a hydraulic hardened body and a carbonation curing system for a hydraulic hardened body. [[Background Art]]

[0002] In recent years, in order to realize a carbon-neutral society, technology for fixing CO₂ to concrete has attracted extremely high attention. In the technology for fixing CO₂ to concrete, by increasing the CO₂ concentration in a tank, carbonation curing is performed during the hardening process of concrete left standing still in the tank, so that CO₂ is absorbed and fixed in the concrete.

[0003] For example, Patent Document 1 describes a curing system for producing a concrete-based final product and curing a material that cannot be completely cured unless CO₂ is present. In the curing system of Patent Document 1, a binding element includes a core containing a predetermined element, a first layer that at least partially covers the core and contains the predetermined element, and a second layer that at least partially covers the first layer and contains the predetermined element. Further, carbon dioxide gas is supplied from a carbon dioxide source to a curing chamber via a gas inflow port, and during curing, the concentration of carbon dioxide gas in the curing chamber, the temperature of carbon dioxide gas, the humidity of carbon dioxide gas, the supply amount of carbon dioxide gas to the curing chamber, and the circulation of carbon dioxide gas present in the curing chamber are controlled.

[0004] However, in a conventional carbonation curing system such as that disclosed in Patent Document 1, not all CO₂ that already exists in the curing chamber before CO₂ is supplied and all CO₂ supplied to the curing chamber are used for carbonation curing, and CO₂ that is not used for carbonation curing leaks from the curing chamber. As described above, CO₂ in the curing chamber is not sufficiently used for carbonation curing and is unnecessarily discharged from the curing chamber. Therefore, there is a demand for increasing the amount of CO₂ in the curing chamber used for carbonation curing and reducing the amount of CO₂ leaking from the curing chamber. [[Prior Art Documents]] [[Patent Documents]]

[0005] [Patent Document 1] Patent No. 6598818 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a method for managing the carbonation curing of hydraulic hardening materials and a carbonation curing system for hydraulic hardening materials that reduces the amount of CO2 leaking from the carbonation curing tank without being used for the carbonation curing of the hydraulic hardening material, thereby enabling efficient use of CO2 in the carbonation curing tank for the carbonation curing of the hydraulic hardening material. [Means for solving the problem]

[0007] [1] A method for managing the carbonation curing of a hydraulically hardened body, comprising: a filling step of filling the inside of a carbonation curing tank containing a hydraulically hardened body with a carbon dioxide-containing gas having a CO2 concentration higher than that of air; a curing step of carbonating the hydraulically hardened body with the carbon dioxide gas filled inside the carbonation curing tank in the filling step; and a discharge step after the curing step of discharging a gas containing at least carbon dioxide from inside the carbonation curing tank to the outside of the carbonation curing tank, wherein the filling step, the curing step and the discharge step are performed under different conditions and controlled according to each step. [2] The method for controlling the carbonation curing of a hydraulic curing body according to [1] above, wherein the filling step comprises a first filling step of filling the carbon dioxide-containing gas without stirring the gas in the carbonation curing tank, and a second filling step performed after the first filling step, in which the carbon dioxide-containing gas is filled after stirring the gas in the carbonation curing tank. [3] The method for controlling the carbonation curing of a hydraulic hardened body according to [1] or [2] above, wherein in the curing step, a unidirectional airflow is generated in the carbonation curing tank to continuously apply a gas containing CO2 to the surface of the hydraulic hardened body. [4] The method for managing carbonation curing of a hydraulic hardened body according to any one of [1] to [3] above, wherein in the curing step, when a differential pressure P (P = P1 - P2) between an internal pressure P1 of the carbonation curing tank and an external pressure P2 of the carbonation curing tank satisfies P ≤ 0, mode 1 is performed, in which a valve at a discharge portion of the carbonation curing tank is closed and the carbon dioxide gas-containing gas is supplied into the interior of the carbonation curing tank. [5] The method for managing carbonation curing of a hydraulic hardened body according to [4] above, wherein in the curing step, when the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank satisfies P > 0, and an offset value P3 used as an allowable internal pressure of the carbonation curing tank satisfies P < P3, mode 2 is performed, in which the valve at the discharge portion of the carbonation curing tank is closed and the carbon dioxide gas-containing gas is supplied into the interior of the carbonation curing tank at a supply rate slower than that in mode 1. [6] The method for managing carbonation curing of a hydraulic hardened body according to any one of [1] to [5] above, wherein in the curing step, when the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank satisfies P > 0, and the offset value P3 used as the allowable internal pressure of the carbonation curing tank satisfies P > P3, mode 3 is performed, in which after the valve at the discharge portion of the carbonation curing tank is opened to discharge gas to the outside of the carbonation curing tank, the valve is closed. [7] The method for managing carbonation curing of a hydraulic hardened body according to any one of [1] to [6] above, wherein the method for managing carbonation curing of a hydraulic hardened body includes a plurality of the carbonation curing tanks, the carbonation curing tanks are connected to each other, and gas containing at least carbon dioxide discharged to the outside of a carbonation curing tank is supplied into the interior of another separate carbonation curing tank. [8] A carbonation curing system for a hydraulically cured body, comprising: a carbonation curing tank for containing a hydraulically cured body; a supply unit for supplying a carbon dioxide-containing gas with a CO2 concentration higher than that of air into the carbonation curing tank; and a discharge unit for discharging a gas containing at least carbon dioxide from the inside of the carbonation curing tank to the outside of the carbonation curing tank, wherein in the carbon dioxide-containing gas filling process, the carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank for filling; in the hydraulically cured body curing process, the hydraulically cured body is carbonated and cured with the carbon dioxide gas filled inside the carbonation curing tank; and in the gas discharge process for the gas containing at least carbon dioxide, after the hydraulically cured body has been cured, the gas containing at least carbon dioxide is discharged to the outside of the carbonation curing tank, wherein the filling process, the curing process, and the discharge process are performed under different conditions and controlled according to each process. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a method for managing the carbonation curing of a hydraulic body and a carbonation curing system for a hydraulic body, which reduces the amount of CO2 that leaks from the carbonation curing tank without being used for the carbonation curing of the hydraulic body, thereby enabling efficient use of CO2 in the carbonation curing tank for the carbonation curing of the hydraulic body. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a flowchart showing the flow of the carbonation curing management method for a hydraulically cured body according to an embodiment. [Figure 2] Figure 2 is a flowchart showing a preferred control flow of the curing process that constitutes the carbonation curing management method for a hydraulically hardened body according to the embodiment. [Figure 3] Figure 3 is a schematic diagram showing a preferred example of a carbonation curing management method for a hydraulically cured body according to the embodiment. [Figure 4] Figure 4 is a schematic diagram showing an example of a carbonation curing system for a hydraulically hardened body according to an embodiment. [Modes for carrying out the invention]

[0010] The following will provide a detailed explanation based on the embodiments.

[0011] The present inventors have diligently researched methods for the carbonation curing of hydraulic curing bodies and have found that by having a filling step of filling with a carbon dioxide-containing gas, a curing step of carbonating the hydraulic curing body, and a discharge step of discharging a gas containing at least carbon dioxide, and by controlling the filling, curing, and discharge steps under different conditions and according to each step, the amount of CO2 leaking from the carbonation curing tank without being used for the carbonation curing of the hydraulic curing body can be reduced, and the CO2 in the carbonation curing tank can be efficiently used for the carbonation curing of the hydraulic curing body. Based on this finding, the present inventors have completed the present invention.

[0012] The present invention provides a method for managing the carbonation curing of a hydraulic curing body, comprising: a filling step of filling a carbon dioxide-containing gas with a CO2 concentration higher than that of air into a carbonation curing tank containing the hydraulic curing body; a curing step of carbonating the hydraulic curing body with the carbon dioxide gas filled into the carbonation curing tank in the filling step; and a discharge step after the curing step of discharging a gas containing at least carbon dioxide from inside the carbonation curing tank to the outside of the carbonation curing tank. The filling step, curing step, and discharge step are controlled under different conditions and according to the specific conditions of each step.

[0013] The carbonation curing system for hydraulic curing bodies of the present invention comprises a carbonation curing tank for containing the hydraulic curing body, a supply unit for supplying a carbon dioxide-containing gas with a CO2 concentration higher than that of air into the carbonation curing tank, and a discharge unit for discharging a gas containing at least carbon dioxide from the inside of the carbonation curing tank to the outside. In the carbon dioxide-containing gas filling process, the carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank for filling; in the hydraulic curing body curing process, the hydraulic curing body is cured by carbonation with the carbon dioxide gas filled inside the carbonation curing tank; and in the carbon dioxide-containing gas discharge process, after the curing of the hydraulic curing body, a gas containing at least carbon dioxide is discharged to the outside of the carbonation curing tank. The filling process, curing process, and discharge process are performed under different conditions and controlled according to each process.

[0014] Fig. 1 is a flowchart showing the flow of a carbonation curing management method for a hydraulic hardened body according to an embodiment. As shown in Fig. 1, the carbonation curing management method for a hydraulic hardened body includes a filling step S10, a curing step S20, and a discharging step S30. In the filling step S10, the curing step S20, and the discharging step S30, control is performed under mutually different conditions and in accordance with each step.

[0015] In the filling step S10, a carbon dioxide-containing gas having a higher CO₂ concentration than air is filled into a carbonation curing tank that accommodates the hydraulic hardened body therein. The carbon dioxide-containing gas is a gas containing carbon dioxide, and is preferably composed solely of carbon dioxide. The CO₂ concentration in the carbon dioxide-containing gas is higher than the CO₂ concentration in air. The hydraulic hardened body is an object to be subjected to carbonation curing in the curing step S20 described later, and can absorb and fix CO₂ by being subjected to carbonation curing (hereinafter, absorption and fixation are collectively referred to as fixation). Further, the carbonation curing tank is, for example, a transportation container.

[0016] The hydraulic hardened body contains cement and hardens by reaction with water, and examples thereof include concrete and mortar. In the curing step S20 described later, CO₂ is fixed to the hydraulic hardened body by performing carbonation curing in which the hydraulic hardened body reacts with carbon dioxide during the hardening process.

[0017] In the filling step S10, from the viewpoint of reducing the amount of CO₂ that leaks from the carbonation curing tank without being used for carbonation curing of the hydraulic hardened body, and efficiently using the carbon dioxide in the carbon dioxide-containing gas for carbonation curing of the hydraulic hardened body, the carbon dioxide-containing gas is preferably filled from the lower part of the carbonation curing tank.

[0018] Note that, although the curing step S20 described later is the main step of performing carbonation curing on the hydraulic hardened body, carbonation curing of the hydraulic hardened body may also occur in the filling step S10. At this time, the degree of carbonation curing in the filling step S10 is smaller than the degree of carbonation curing in the curing step S20.

[0019] The filling step S10 includes a first filling step S11 of filling a carbon dioxide-containing gas into a carbonation curing tank without stirring the gas in the carbonation curing tank, and a second filling step S12 performed after the first filling step S11, in which the carbon dioxide-containing gas is filled into the carbonation curing tank after stirring the gas in the carbonation curing tank.

[0020] In the first filling step S11, the carbon dioxide-containing gas is filled without stirring the inside of the carbonation curing tank. Further, in the first filling step S11, an air conditioning facility is not operated. As described above, in the first filling step S11, by statically filling the carbon dioxide-containing gas without stirring the inside of the carbonation curing tank, carbon dioxide is easily accumulated in the lower part of the carbonation curing tank, and a vertical CO₂ concentration difference in the carbonation curing tank, which is a concentration state where the CO₂ concentration in the lower part of the carbonation curing tank is higher than the CO₂ concentration in the upper part of the carbonation curing tank, is positively provided. In this state, the gas with low CO₂ concentration occupying the upper part of the carbonation curing tank is discharged to the outside of the carbonation curing tank without stirring the inside of the carbonation curing tank. Thus, the first filling step S11 is completed.

[0021] In the first filling step S11, the gas with high CO₂ concentration accumulated in the lower part of the carbonation curing tank is not discharged to the outside of the carbonation curing tank. Furthermore, in the first filling step S11, the inside of the carbonation curing tank is not stirred during filling of the carbon dioxide-containing gas to uniformize the CO₂ concentration in the carbonation curing tank, and the gas with uniformized CO₂ concentration is not discharged to the outside of the carbonation curing tank. Therefore, unnecessary release of carbon dioxide from the carbonation curing tank can be suppressed. Note that, compared with the gas obtained by uniformizing the CO₂ concentration in the carbonation curing tank, the gas occupying the lower part of the carbonation curing tank when the inside of the carbonation curing tank is not stirred as in the first filling step S11 has a higher CO₂ concentration.

[0022] Thus, in the first filling step S11, by filling with carbon dioxide-containing gas without operating the air conditioning equipment, it is easy to create a state in which carbon dioxide in the carbonation curing tank does not mix with other gases. Therefore, the CO2 concentration in the carbonation curing tank can be easily controlled to above the desired value in a short time. Furthermore, since the air conditioning equipment is not operated, the gas with a low CO2 concentration that occupies the upper part is not conditioned, and unnecessary power consumption can be avoided when discharging it to the outside of the carbonation curing tank.

[0023] From the viewpoint of reducing the amount of carbon dioxide leaking from the carbonation curing tank, it is preferable to discharge the gas containing carbon dioxide from the upper part of the carbonation curing tank when the ratio of the CO2 concentration in the upper part of the carbonation curing tank to the CO2 concentration in the lower part of the tank (upper CO2 concentration / lower CO2 concentration) is 0.4 or less. Furthermore, it is even more desirable to reduce the above CO2 concentration ratio to 0.1 or less by slowing the filling rate of the gas containing carbon dioxide to 100 liters / minute or less as time permits.

[0024] The second filling process S12, which follows the first filling process S11, involves stirring the carbonation curing tank and then filling it again with carbon dioxide-containing gas. In addition, the air conditioning equipment is not operated during the second filling process S12.

[0025] First, in the second filling step S12, with the filling of carbon dioxide-containing gas stopped, the gas in the carbonation curing tank is stirred to homogenize the CO2 concentration inside the tank. By stirring the inside of the carbonation curing tank in this way, the CO2 concentration, temperature, and humidity inside the tank can be measured accurately regardless of where the CO2 concentration sensor, temperature sensor, and humidity sensor are installed inside the tank. Therefore, the overall state inside the carbonation curing tank can be easily grasped, and the inside of the carbonation curing tank can be efficiently controlled to achieve the desired carbonation curing conditions.

[0026] For example, in the first filling step S11, taking into consideration the volume inside the carbonation curing tank and the filling rate of the carbon dioxide-containing gas, the carbon dioxide-containing gas is filled into the carbonation curing tank until the amount of CO2 input matches the desired CO2 concentration. Then, in the second filling step S12, the carbonation curing tank is stirred so that the values ​​of various sensors, such as the CO2 concentration, match or nearly match the desired values.

[0027] The gas in the carbonation curing tank is stirred by a blower installed inside the tank. The blower stirs the gas in the carbonation curing tank and is different from the air conditioning equipment that adjusts the temperature and humidity inside the tank. However, in addition to the blower, it is also possible to stir the gas more efficiently by using only the blower function while the air conditioning function of the air conditioning equipment is stopped.

[0028] Furthermore, in the second filling step S12, after homogenizing the CO2 concentration in the carbonation curing tank and completing the stirring within the tank, the carbon dioxide-containing gas is filled into the carbonation curing tank again. Then, after the CO2 concentration in the carbonation curing tank reaches the desired value, the filling of the carbon dioxide-containing gas is stopped. Thus, the second filling step S12 is completed.

[0029] The curing process S20, which follows the filling process S10, involves carbonicating the hydraulic curing body with carbon dioxide gas that was filled into the carbonation curing tank during the filling process S10. In this way, a hydraulic curing body with immobilized carbon dioxide gas can be obtained.

[0030] In curing process S20, the air conditioning system is operated to generate a unidirectional airflow within the carbonation curing tank, continuously applying the CO2-containing airflow to the surface of the hydraulic curing body. The unidirectional airflow within the carbonation curing tank can be generated, for example, by a blower, as well as by the air supply duct and intake port of the air conditioning system installed within the carbonation curing tank.

[0031] The intake port of the air conditioning system is located on the side opposite the blower in the carbonation curing tank. The air supply port of the air supply duct is located around the blower and faces the blower. The hydraulically hardened material is installed between the air supply port of the air supply duct and the intake port of the air conditioning system, which are positioned opposite each other. In this way, the air supply duct and the intake port of the air conditioning system are positioned separately.

[0032] The CO2-containing gas, whose temperature and humidity have been adjusted by the operating air conditioning system, is released from the air supply port of the air supply duct located at the top of the carbonation curing tank toward a blower. The blower blows the temperature and humidity-adjusted gas toward the intake port of the air conditioning system installed beyond the hydraulic curing body. As the temperature and humidity-adjusted gas flows toward the intake port of the air conditioning system, it comes into contact with the hydraulic curing body, which promotes and accelerates the carbonation curing of the hydraulic curing body, and also generates water vapor from the hydraulic curing body.

[0033] After contact with the hydraulically hardened material, the gas experiences a decrease in CO2 concentration and an increase in humidity. This gas, with its reduced CO2 concentration and increased humidity, is drawn into the air intake of the air conditioning system along with other gases that have a higher CO2 concentration and lower humidity than this gas. Furthermore, when carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank, air with a higher CO2 concentration than the gas with reduced CO2 concentration and increased humidity is also drawn into the air intake of the air conditioning system. The air drawn in from the intake is sent to the air conditioning system, which adjusts the temperature and humidity and mixes gases with different CO2 concentrations. The gas, whose temperature and humidity have been adjusted and whose CO2 concentration has been maintained by the air conditioning system, is then released again from the air supply duct towards the fan.

[0034] In this way, by continuously and forcibly bringing a gas with controlled temperature and humidity and maintained CO2 concentration into contact with the surface of the hydraulic curing material as a unidirectional airflow, the generation of airflow turbulence, stagnant gas, and localized airflow loops caused by the arrangement of the hydraulic curing material can be suppressed. Therefore, the CO2 in the carbonation curing tank can be used efficiently to efficiently perform carbonation curing of the hydraulic curing material with minimal unevenness. Furthermore, because the air supply port of the air supply duct and the air intake port of the air conditioning equipment are positioned opposite each other, the water vapor generated from the hydraulic curing material during carbonation curing can be efficiently taken into the air conditioning equipment from the downstream intake port by the unidirectional airflow. As a result, the dehumidification efficiency in the carbonation curing tank is improved.

[0035] In other words, in the curing process S20, the air conditioning system adjusts the temperature, humidity, and CO2 concentration, a blower blows the gas adjusted in temperature, humidity, and CO2 concentration by the air conditioning system onto the hydraulic curing body, the hydraulic curing body is cured by carbonation using the gas adjusted in temperature, humidity, and CO2 concentration, the blower blows the gas after carbonation curing back onto the air conditioning system, and the air conditioning system adjusts the temperature, humidity, and CO2 concentration of the gas blown by the blower. This cycle is carried out continuously and forcibly.

[0036] Furthermore, the curing process S20 preferably follows the control flow described below. Figure 2 is a flowchart showing a preferred control flow for the curing process S20.

[0037] As shown in Figure 2, first, an offset value P3 is set for the differential pressure sensor to be used as the allowable internal pressure of the carbonation curing tank. The offset value P3 can be set appropriately according to the internal volume of the carbonation curing tank, etc. The maximum value of the offset value P3 (MPa) is 0.004 / internal volume of the carbonation curing tank (m³) 3 It is preferable that the value is less than or equal to the value of (maximum value of offset value P3 ≤ 0.004 / internal volume of the carbonation curing tank). The differential pressure sensor measures the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 (atmospheric pressure) of the carbonation curing tank.

[0038] Next, with the aim of reducing the amount of CO2 leaking from the carbonation curing tank without being used for the carbonation curing of the hydraulic body, and efficiently using the CO2 in the carbonation curing tank for the carbonation curing of the hydraulic body, a mode determination is made based on the differential pressure sensor measurement and the offset value P3, and one of the following modes 1, mode 2, or mode 3 is performed. In this way, the control mode at that time is determined by the differential pressure sensor.

[0039] In Mode 1, when the differential pressure sensor measurement result is differential pressure P ≤ 0, the valve at the discharge end of the carbonation curing tank (preferably the overflow valve 41a described later) is closed, and carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank. In Mode 1, as the carbonation curing of the hydraulic body progresses, carbon dioxide is fixed to the hydraulic body, and carbon dioxide-containing gas is supplied to the carbonation curing tank to compensate for the pressure drop (reduced pressure) caused by the loss of a volume of gas from the carbonation curing tank equivalent to the amount of fixed carbon dioxide. Therefore, the CO2 concentration inside the carbonation curing tank at the start of curing process S20 can be maintained to a general extent.

[0040] Since the internal pressure P1 of the carbonation curing tank is less than or equal to the external pressure P2 of the carbonation curing tank, even if carbon dioxide-containing gas is supplied into the carbonation curing tank, no carbon dioxide leakage to the outside of the carbonation curing tank occurs. Thus, in Mode 1, the amount of CO2 lost due to carbonation curing is continuously supplied to the carbonation curing tank, so the internal pressure P1 of the carbonation curing tank never exceeds the external pressure P2, and the amount of CO2 leaking from the carbonation curing tank can be reduced.

[0041] Furthermore, if the opening and closing of the valve at the discharge end of the carbonation curing tank is controlled in conjunction with the pressure measured by the differential pressure sensor, controlling the valve to open when the differential pressure P is -300 Pa or less can suppress damage to sealing materials such as packings that make up the valve at the discharge end of the carbonation curing tank, and can suppress abnormal pressure inside the carbonation curing tank caused by damage to the sealing materials.

[0042] In Mode 2, when the differential pressure sensor measurement result is differential pressure P > 0 and differential pressure P < offset value P3, the valve at the discharge end of the carbonation curing tank is closed and carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank, but the supply rate of carbon dioxide-containing gas can be set to a lower value than in Mode 1. As the carbonation curing of the hydraulic body progresses, carbon dioxide gas is fixed to the hydraulic body, and a decrease in internal pressure occurs due to the loss of a volume of gas from inside the carbonation curing tank equivalent to the amount of fixed carbon dioxide gas, as well as an increase in internal pressure due to the rise in temperature and humidity inside the carbonation curing tank, and the generation of moisture (water vapor pressure) from the hydraulic body.

[0043] Since the differential pressure P is smaller than the offset value P3, which is the allowable internal pressure of the carbonation curing tank, the internal pressure of the carbonation curing tank is within the allowable range. Therefore, in mode 2, efficient carbonation curing can be performed by preventing CO2 leakage due to the opening of the valve at the discharge end of the carbonation curing tank and by supplying carbon dioxide-containing gas at a lower supply rate than in mode 1.

[0044] In Mode 3, when the differential pressure sensor measurement result is differential pressure P > 0 and differential pressure P > offset value P3, the valve at the discharge port of the carbonation curing tank is opened to discharge the gas inside the carbonation curing tank 2 to the outside of the carbonation curing tank 2, and then the valve at the discharge port of the carbonation curing tank is closed. In Mode 3, the internal pressure of the carbonation curing tank is even higher than in Mode 2, and the pressure resistance state of the carbonation curing tank is unacceptable. Therefore, the valve at the discharge port of the carbonation curing tank is opened to discharge the gas inside the carbonation curing tank and reduce it to an acceptable internal pressure, and then the valve at the discharge port of the carbonation curing tank is closed again. After that, carbon dioxide-containing gas may be supplied into the carbonation curing tank.

[0045] Thus, in Mode 3, the leakage of carbon dioxide gas can be minimized while the pressure-impaired state of the carbonation curing tank can be quickly resolved by temporarily opening the valve at the discharge end of the carbonation curing tank.

[0046] Furthermore, if the curing of the hydraulically hardened material is not yet complete, this control mode is repeated.

[0047] If, for example, the differential pressure sensor measurement result is differential pressure P ≤ 0, and carbon dioxide-containing gas is not supplied to the carbonation curing tank, the internal pressure of the carbonation curing tank will decrease, causing air from outside the carbonation curing tank to be drawn in through gaps in the sealing material such as packing that makes up the valve of the carbonation curing tank's discharge port, which can lead to a decrease in the CO2 concentration inside the carbonation curing tank. Also, if carbon dioxide-containing gas is supplied to the carbonation curing tank regardless of the differential pressure P, the internal pressure of the carbonation curing tank will increase, pushing the CO2-containing gas out of the carbonation curing tank through gaps in the sealing material that makes up the valve of the carbonation curing tank's discharge port, resulting in wasted CO2. Therefore, these problems can be solved by performing control according to the differential pressure P of the carbonation curing tank using modes 1 to 3.

[0048] Thus, the control flow described above measures the differential pressure P in the carbonation curing tank and controls the curing process S20 based on the measured differential pressure P, thereby reducing the amount of CO2 leaking from the carbonation curing tank.

[0049] Furthermore, by separating the filling process S10 and the curing process S20, it is possible to reduce the unnecessary release of CO2 from the carbonation curing tank, as well as reduce the amount of electricity consumed by air conditioning equipment such as heating, cooling, and dehumidification.

[0050] The discharge process S30, which is performed after the curing process S20, discharges gas containing at least carbon dioxide that was not used for the carbonation curing of the hydraulic hardened body in the curing process S20 from inside the carbonation curing tank to outside the carbonation curing tank.

[0051] In the discharge process S30, a gas containing at least carbon dioxide is exhausted to the outside of the carbonation curing tank to the extent that the safety of workers can be ensured even if workers enter the carbonation curing tank. Furthermore, the inside of the carbonation curing tank is ventilated as needed to reduce the CO2 concentration inside the carbonation curing tank.

[0052] Figure 3 is a schematic diagram showing a preferred example of a carbonation curing management method for a hydraulically cured body according to the embodiment. Note that the schematic diagram in Figure 3 is simplified.

[0053] If the CO2 concentration of the gas discharged in the carbonation curing tank discharge process S30 is higher than that of air, as shown in Figure 3, it is preferable that the carbonation curing management method for the hydraulic curing body H connects multiple carbonation curing tanks 2 (21, 22) and supplies the gas containing at least carbon dioxide discharged to the outside of carbonation curing tank 21 into a separate carbonation curing tank 22 from which the gas was discharged. The separate carbonation curing tank 22 has the same configuration as the carbonation curing tank 21 and can perform the filling process S10, curing process S20, and discharge process S30.

[0054] By discharging the carbon dioxide-containing gas, which is a gas with a higher CO2 concentration than air and is discharged from the exhaust section 91 having an exhaust valve 91a and an exhaust fan 92 to the outside of the carbonation curing tank 21, and filling a separate carbonation curing tank 22 from the intake section 93 having an intake three-way valve 93b, the CO2 exhausted from the carbonation curing tank 21 can be reused for the carbonation curing of the hydraulic curing body H contained in the separate carbonation curing tank 22. Therefore, the amount of CO2 that leaks from the carbonation curing tank without being used for the carbonation curing of the hydraulic curing body can be further reduced.

[0055] Furthermore, if the CO2 concentration of the gas discharged from the carbonation curing tank 22 is higher than that of air, the amount of CO2 leaking from the carbonation curing tank 21 without being used for the carbonation curing of the hydraulic curing body can be further reduced by filling the carbonation curing tank 21 with the carbon dioxide-containing gas discharged from the exhaust section 91 of the carbonation curing tank 22 through the intake three-way valve 93b of the intake section 93.

[0056] Furthermore, when the carbonation curing tanks 21 and 22 take in outside air, the intake three-way valve 93b is switched to the outside side. Also, when multiple carbonation curing tanks 21 and 22 are not connected, the intake three-way valve 93b is replaced with the intake valve 93a, which is a two-way valve and will be described later.

[0057] Next, a carbonation curing system for hydraulically hardened bodies according to an embodiment will be described.

[0058] Figure 4 is a schematic diagram showing an example of a carbonate curing system for a hydraulically hardened body according to the embodiment. The carbonate curing system for a hydraulically hardened body according to the embodiment is a system that performs the carbonate curing management method for a hydraulically hardened body according to the above embodiment.

[0059] As shown in Figure 4, the carbonate curing system 1 for hydraulic curing bodies includes a carbonate curing tank 2 for containing the hydraulic curing body H, a supply unit 3 for supplying a carbon dioxide-containing gas with a CO2 concentration higher than that of air into the carbonate curing tank 2, and a discharge unit 41 for discharging a gas containing at least carbon dioxide from inside the carbonate curing tank 2 to the outside of the carbonate curing tank 2. For example, the hydraulic curing body H is placed on a support 5 such as a rectangular timber. The carbonation curing system 1 for the hydraulic body contains carbon dioxide, which is supplied to the inside of the carbonation curing tank 2 for filling; carbon dioxide, which is used to cure the hydraulic body H; and carbon dioxide, which is used to cure the hydraulic body H with the carbon dioxide filled inside the carbonation curing tank 2. In the discharge treatment of gas containing at least carbon dioxide, after the curing of the hydraulic body H, gas containing at least carbon dioxide is discharged to the outside of the carbonation curing tank 2. The filling treatment of carbon dioxide, the curing treatment of the hydraulic body, and the discharge treatment of gas are performed under different conditions and controlled according to each treatment.

[0060] In the carbonate curing system 1 for hydraulically cured bodies, the filling process, curing process, and discharge process correspond to the filling process S10, curing process S20, and discharge process S30, respectively, in the carbonate curing management method for hydraulically cured bodies of the above embodiment.

[0061] Furthermore, the carbonation curing system 1 includes a blower 6 for stirring the gas inside the carbonation curing tank 2, a differential pressure sensor 7 for measuring the differential pressure P between the internal pressure P1 and external pressure P2 of the carbonation curing tank 2, and an air conditioning system 8 installed inside the carbonation curing tank 2. For example, the blower 6 is positioned opposite the supply unit 3 and blows air away from the carbon dioxide delayed discharge mechanism 4. Also, the air supply duct 81 of the air conditioning system 8 is installed inside the carbonation curing tank 2, and the intake port 8a of the air conditioning system 8 is located inside the carbonation curing tank 2.

[0062] Furthermore, the carbonate curing system 1 for hydraulically hardened bodies preferably has the following configuration.

[0063] The supply unit 3 supplies carbon dioxide-containing gas from outside the carbon dioxide curing tank 2 to the inside of the carbon dioxide curing tank 2 through a supply opening 2a provided in the side wall of the carbon dioxide curing tank 2. The supply unit 3 is equipped with a supply valve 3a and is connected to a CO2 supply device 3b. The CO2 supply device 3b supplies carbon dioxide-containing gas to the supply unit 3. In addition, if necessary, the CO2 concentration, temperature, and CO2 supply rate of the carbon dioxide-containing gas supplied from the CO2 supply device 3b to the supply unit 3 may be adjusted by an adjustment unit (not shown).

[0064] The carbon dioxide-containing gas supplied from the CO2 supply equipment 3b to the supply unit 3 is then supplied from the supply unit 3 into the carbonation curing tank 2. The stopping and starting (restarting) of the supply of carbon dioxide-containing gas into the carbonation curing tank 2, as well as the adjustment of the amount of carbon dioxide-containing gas supplied into the carbonation curing tank 2, are controlled by the supply valve 3a of the supply unit 3.

[0065] When filling the carbonation curing tank 2 with carbon dioxide-containing gas, in order to reduce the amount of CO2 that leaks from the carbonation curing tank 2 without being used for the carbonation curing of the hydraulic body H, and to efficiently use the carbon dioxide in the carbon dioxide-containing gas supplied from the supply unit 3 for the carbonation curing of the hydraulic body H, it is preferable that the supply unit 3 be provided at the lower part of the side wall of the carbonation curing tank 2, and more preferably at the lower part of the side wall of the carbonation curing tank 2 facing the carbon dioxide delayed discharge mechanism 4, which will be described later.

[0066] Furthermore, by dividing the supply unit 3 into multiple supply units, carbon dioxide-containing gas can be supplied separately from multiple positions on the lower part of the side wall of the carbonation curing tank 2. This reduces the supply rate of carbon dioxide-containing gas per supply unit, and further reduces the ratio of the CO2 concentration in the upper part of the carbonation curing tank to the CO2 concentration in the lower part of the carbonation curing tank (upper CO2 concentration / lower CO2 concentration), which is preferable.

[0067] The carbonation curing system 1 for hydraulic curing bodies is equipped with a carbon dioxide delayed discharge mechanism 4. The carbon dioxide delayed discharge mechanism 4 discharges at least air and gas containing carbon dioxide (hereinafter also simply referred to as gas) from inside the carbonation curing tank 2 to outside the carbonation curing tank 2, and preferentially discharges air to outside the carbonation curing tank 2 over carbon dioxide. The air contained in the gas discharged to outside the carbonation curing tank 2 is the air that was already present inside the carbonation curing tank 2 before the supply unit 3 supplied the carbon dioxide-containing gas, and if the carbon dioxide-containing gas supplied from the supply unit 3 contains air, it also includes the air in the carbon dioxide-containing gas supplied from the supply unit 3.

[0068] The carbon dioxide delayed discharge mechanism 4 utilizes the difference in weight between air and carbon dioxide to preferentially discharge air over carbon dioxide to the outside of the carbonation curing tank 2. In other words, the carbon dioxide delayed discharge mechanism 4 delays the discharge of carbon dioxide compared to air. Furthermore, if the carbon dioxide-containing gas supplied from the supply unit 3 contains substances other than carbon dioxide and air, these other substances are also discharged from the carbon dioxide delayed discharge mechanism 4 to the outside of the carbonation curing tank 2.

[0069] Such a carbon dioxide delayed emission mechanism 4 comprises an emission section 41 and a carbon dioxide delay section 42.

[0070] The discharge section 41, which constitutes the carbon dioxide delayed discharge mechanism 4, discharges a gas containing at least air and carbon dioxide from inside the carbon dioxide curing tank 2 to the outside of the carbon dioxide curing tank 2 through a discharge opening 2b provided in the side wall of the carbon dioxide curing tank 2. The discharge section 41 is provided in the upper part of the side wall of the carbon dioxide curing tank 2.

[0071] An overflow valve 41a is provided in the discharge section 41. The stopping and starting (restarting) of gas discharge to the outside of the carbonation curing tank 2, as well as the adjustment of the amount of gas discharged to the outside of the carbonation curing tank 2, are controlled by the overflow valve 41a of the carbon dioxide delayed discharge mechanism 4.

[0072] The carbon dioxide delay section 42, which constitutes the carbon dioxide delayed discharge mechanism 4, circulates the gas from the top to the bottom of the carbonation curing tank 2, and supplies the gas that has circulated to the top of the carbonation curing tank 2 with a flow path cross-sectional area S2 that is smaller than the flow path cross-sectional area S1 when the gas circulates to the bottom of the carbonation curing tank 2, to the discharge section 41. In the carbon dioxide delay section 42, the flow path cross-sectional area S2 when the gas circulates from the bottom to the top of the carbonation curing tank 2 is smaller than the flow path cross-sectional area S1 when the gas circulates from the top to the bottom of the carbonation curing tank 2.

[0073] In this way, the carbon dioxide delay unit 42 utilizes the difference between the flow path cross-sectional areas S1 and S2 to circulate the gas present in the upper part of the carbonation curing tank 2 downwards through the flow path cross-sectional area S1, and the gas that has circulated downwards in the carbonation curing tank 2 upwards through the flow path cross-sectional area S2, which is smaller than the flow path cross-sectional area S1. This allows air to be supplied to the discharge unit 41 preferentially over carbon dioxide. Thus, the carbon dioxide delay discharge mechanism 4 can preferentially discharge air to the outside of the carbonation curing tank 2 via the discharge unit 41, rather than carbon dioxide.

[0074] The carbon dioxide delay unit 42 having such a configuration preferably has an inner cylinder 42a and an outer cylinder 42b.

[0075] The inner cylinder 42a, which constitutes the carbon dioxide delay section 42, has its upper end connected to the discharge section 41, extends downward, and has an open lower end. The inner cylinder 42a extends to near the inner surface of the lower end of the outer cylinder 42b.

[0076] The outer cylinder 42b, which constitutes the carbon dioxide delay section 42, has a closed lower end and extends upward, covering the outer circumference of the inner cylinder 42a from the outside. In this way, the inner cylinder 42a and the outer cylinder 42b, which covers the entire circumference of the inner cylinder from the outside, have a double-cylinder structure.

[0077] The lower end of the inner cylinder 42a and the inner surface of the lower end of the outer cylinder 42b are not in contact and are non-contact. For example, the lower limit of the vertical distance d between the lower end of the inner cylinder 42a and the inner surface of the lower end of the outer cylinder 42b is preferably 20 mm or more, and the upper limit is preferably 150 mm or less. When the above distance d is 20 mm or more, even if condensation water is generated between the lower end of the inner cylinder 42a and the lower end of the outer cylinder 42b, the gas can flow smoothly. Also, when the above distance d is 150 mm or less, the airflow stabilization effect achieved by the length of the inner cylinder 42a and the outer cylinder 42b is good.

[0078] The lower end of the outer cylinder 42b may be connected to the bottom of the carbonation curing tank 2. If the lower end of the outer cylinder 42b is connected to the bottom of the carbonation curing tank 2, the lower end of the outer cylinder 42b may be open, and the bottom portion of the carbonation curing tank 2 connected to the lower end of the outer cylinder 42b also serves as the inner surface of the lower end of the outer cylinder 42b.

[0079] The outer cylinder 42b extends to a position below the upper end of the inner cylinder 42a. The upper end of the outer cylinder 42b is open.

[0080] A drain pipe 43 may be provided at the lower end of the outer cylinder 42b for discharging a small amount of water (including condensation) to the outside of the carbonation curing tank 2. A drain valve 43a is provided in the drain pipe 43.

[0081] The gas flows in from the upper end of the outer cylinder 42b, circulates downward through the outer cylinder 42b, then flows from the lower end of the outer cylinder 42b to the lower end of the inner cylinder 42a, circulates upward through the inner cylinder 42a, and then flows from the upper end of the inner cylinder 42a to the discharge section 41.

[0082] The flow path cross-sectional area S2 of the inner cylinder 42a, which allows gas to flow from bottom to top, is smaller than the flow path cross-sectional area S1 of the outer cylinder 42b, which allows gas to flow from top to bottom. This double-cylinder structure of the inner cylinder 42a and outer cylinder 42b allows air to be supplied preferentially to the discharge section 41 over carbon dioxide gas when considering the carbon dioxide gas and air contained in the gas in the carbonation curing tank 2.

[0083] From the viewpoint that the double-cylinder structure of the inner cylinder 42a and outer cylinder 42b provides even greater priority to supplying air to the discharge section 41 than carbon dioxide, it is preferable that the supply flow velocity of the carbon dioxide-containing gas supplied from the supply section 3 to the inside of the carbonation curing tank 2 (hereinafter also simply referred to as the supply flow velocity of the carbon dioxide-containing gas) > the flow velocity of the gas circulating upward in the inner cylinder 42a (hereinafter also simply referred to as the flow velocity in the inner cylinder 42a) > the flow velocity of the gas circulating downward in the outer cylinder 42b (hereinafter also simply referred to as the flow velocity in the outer cylinder 42b), the flow velocity in the inner cylinder 42a being 20% ​​or less of the supply flow velocity of the carbon dioxide-containing gas, and the flow velocity in the outer cylinder 42b being 5% or less of the supply flow velocity of the carbon dioxide-containing gas. On the other hand, while increasing the flow velocity difference improves the above effect, it also increases the size of the inner cylinder 42a and the outer cylinder 42b. Therefore, the flow velocity difference may be appropriately selected according to the constraints on the arrangement of the inner cylinder 42a and the outer cylinder 42b within the carbonation curing tank 2.

[0084] In the first half of the carbon dioxide-containing gas filling process (corresponding to the first filling process S11 described above), the carbon dioxide-containing gas is supplied from the supply unit 3 located below the carbon dioxide-containing tank 2 without stirring the gas inside the carbon dioxide-curing tank 2. This easily creates a state where the CO2 concentration is high below the carbon dioxide-curing tank 2 and low above the carbon dioxide-curing tank 2. The gas present above the carbon dioxide-curing tank 2, i.e., the gas with a low CO2 concentration, flows into the carbon dioxide-delayed discharge mechanism 4, which then actively discharges air rather than carbon dioxide from the carbon dioxide-containing tank 2.

[0085] In this way, by statically supplying (filling) carbon dioxide-containing gas within the carbonation curing tank 2 without stirring the gas inside, the difference in CO2 concentration between the upper and lower parts of the carbonation curing tank 2 is actively increased. As a result, the gas with a lower CO2 concentration at the top of the carbonation curing tank 2 flows into the carbon dioxide delayed discharge mechanism 4, which then actively discharges the air outside the carbonation curing tank 2. In this way, when filling the carbon dioxide-containing gas into the carbonation curing tank 2, the amount of CO2 that leaks out of the carbonation curing tank 2 without being used for the carbonation curing of the hydraulic curing body H is reduced, thereby reducing the amount of CO2 wasted from the carbonation curing tank 2 and allowing the CO2 inside the carbonation curing tank 2 to be efficiently used for the carbonation curing of the hydraulic curing body H.

[0086] Furthermore, the carbonation curing system 1 may further include an exhaust section 91 having an exhaust valve 91a and an intake section 93 having an intake valve 93a, which are provided in the carbonation curing tank 2, as well as an exhaust fan 92 provided in the exhaust section 91. For example, in the discharge process S30 (discharge treatment), when it is desired to ventilate the carbonation curing tank 2, the gas inside the carbonation curing tank 2 is discharged back into the carbonation curing tank 2 by opening the exhaust valve 91a and operating the exhaust fan 92, while the intake valve 93a is opened to draw in air from outside the carbonation curing tank 2. Also, when multiple carbonation curing tanks 21 and 22 are connected as described above, the intake valve 93a, which is a two-way valve, is changed to an intake three-way valve 93b.

[0087] According to the embodiments described above, the system includes a filling step (filling process) for filling with a carbon dioxide-containing gas, a curing step (curing process) for carbonicating and curing the hydraulic body, and a discharge step (discharge process) for discharging a gas containing at least carbon dioxide. By controlling the filling, curing, and discharge steps under different conditions and according to each step (each process), the amount of CO2 leaking from the carbonation curing tank without being used for the carbonation curing of the hydraulic body is reduced, and the CO2 in the carbonation curing tank can be efficiently used for the carbonation curing of the hydraulic body.

[0088] Although embodiments have been described above, the present invention is not limited to the embodiments described above, and includes all aspects included in the concepts and claims of this disclosure, and can be modified in various ways within the scope of this disclosure. [Explanation of Symbols]

[0089] 1. Carbonation curing system for hydraulically hardened materials 2, 21, 22 Carbonation curing tanks 2a Supply opening 2b Ejection opening 3 Supply section 3a Supply valve 3b CO2 supply equipment 4. Delayed carbon dioxide emission mechanism 41 Discharge section 41a Overflow valve 42 Carbon dioxide delay section 42a Inner cylinder 42b Outer cylinder 43 Drain pipe 43a Drain valve 5 Support 6. Blower 7. Differential pressure sensor 8 Air conditioning equipment 8a Air intake for air conditioning equipment 81 Air supply duct 91 Exhaust section 91a Exhaust valve 92 Exhaust fan 93 Intake section 93a Intake valve 93b Intake three-way valve H Hydraulic hardening body

Claims

1. Inside the carbonation curing tank containing the hydraulically hardened body, CO2 is present, rather than air. ２ A filling process in which a gas containing a high concentration of carbon dioxide is filled, A curing step in which the hydraulic hardened body is carbonated and cured by carbon dioxide gas filled inside the carbonation curing tank in the filling step, After the curing process, a discharge process is performed to discharge a gas containing at least carbon dioxide from inside the carbonation curing tank to outside the carbonation curing tank. It has, In the filling process, the curing process, and the discharge process, different conditions are applied to each process, and control is performed according to each process. In the curing process described above, when the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank is P ≤ 0, A method for managing the carbonation curing of a hydraulic curing body, comprising performing Mode 1, which involves closing the valve at the discharge section of the carbonation curing tank and supplying the carbon dioxide-containing gas into the carbonation curing tank.

2. In the curing process, when the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank is P > 0, and the offset value P3 used as the allowable internal pressure of the carbonation curing tank is P < P3, The method for managing the carbonation curing of a hydraulic curing body according to claim 1, further comprising performing mode 2, in which the valve of the discharge section of the carbonation curing tank is closed and the carbon dioxide-containing gas is supplied into the carbonation curing tank at a slower supply rate than mode 1.

3. Inside the carbonation curing tank containing the hydraulically hardened body, CO2 is present, rather than air. ２ A filling process in which a gas containing a high concentration of carbon dioxide is filled, A curing step in which the hydraulic hardened body is carbonated and cured by carbon dioxide gas filled inside the carbonation curing tank in the filling step, After the curing process, a discharge process is performed to discharge a gas containing at least carbon dioxide from inside the carbonation curing tank to outside the carbonation curing tank. It has, In the filling process, the curing process, and the discharge process, different conditions are applied to each process, and control is performed according to each process. In the curing process, when the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank is P > 0, and the offset value P3 used as the allowable internal pressure of the carbonation curing tank is P > P3, A method for managing the carbonation curing of a hydraulic curing body, comprising mode 3, in which a valve at the discharge section of the carbonation curing tank is opened to discharge gas to the outside of the carbonation curing tank, and then the valve is closed.

4. Inside the multiple carbonation curing tanks containing the hydraulically hardened body, CO2 is present, rather than air. ２ A filling process in which a gas containing a high concentration of carbon dioxide is filled, A curing step in which the hydraulic hardened body is carbonated and cured by carbon dioxide gas filled inside the plurality of carbonation curing tanks in the filling step, After the curing process, a discharge process is performed to discharge a gas containing at least carbon dioxide from inside the plurality of carbonation curing tanks to the outside of the plurality of carbonation curing tanks. It has, The plurality of carbonation curing tanks are connected to each other, and a gas containing at least carbon dioxide discharged from one carbonation curing tank is supplied to the inside of another carbonation curing tank. A method for managing the carbonation curing of a hydraulically hardened body, wherein the filling step, curing step, and discharge step in each of the plurality of carbonation curing tanks are performed under different conditions and controlled according to each step.

5. A carbonation curing tank for containing a hydraulically hardened body, CO2 is stronger than air. ２ A supply unit that supplies a highly concentrated carbon dioxide-containing gas into the carbonation curing tank, A gas containing at least carbon dioxide is discharged from the inside of the carbonation curing tank to the outside of the carbonation curing tank, and a discharge section having a valve is provided. A differential pressure sensor measures the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank. Equipped with, In the carbon dioxide-containing gas filling process, the carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank and filled. In the curing treatment of the hydraulic curing body, the hydraulic curing body is cured by carbon dioxide gas filled inside the carbonation curing tank. In the aforementioned gas discharge treatment containing at least carbon dioxide, after the curing of the hydraulic hardened body, the gas containing at least carbon dioxide is discharged to the outside of the carbonation curing tank. The filling process, the curing process, and the discharge process are carried out under different conditions and controlled according to each process. In the curing process described above, when the differential pressure P measured by the differential pressure sensor is P ≤ 0, A carbonate curing system for hydraulic curing bodies, comprising Mode 1, in which the valve of the discharge section of the carbonate curing tank is closed and the carbon dioxide-containing gas is supplied into the carbonate curing tank.

6. A carbonation curing tank for containing a hydraulically hardened body, CO2 is stronger than air. ２ A supply unit that supplies a highly concentrated carbon dioxide-containing gas into the carbonation curing tank, A gas containing at least carbon dioxide is discharged from the inside of the carbonation curing tank to the outside of the carbonation curing tank, and a discharge section having a valve is provided. A differential pressure sensor is used to measure the differential pressure P (P = P1 - P2) between the internal pressure P1 of the carbonation curing tank and the external pressure P2 of the carbonation curing tank, and an offset value P3 used as the allowable internal pressure of the carbonation curing tank is set. Equipped with, In the carbon dioxide-containing gas filling process, the carbon dioxide-containing gas is supplied to the inside of the carbonation curing tank and filled. In the curing treatment of the hydraulic curing body, the hydraulic curing body is cured by carbon dioxide gas filled inside the carbonation curing tank. In the aforementioned gas discharge treatment containing at least carbon dioxide, after the curing of the hydraulic hardened body, the gas containing at least carbon dioxide is discharged to the outside of the carbonation curing tank. The filling process, the curing process, and the discharge process are carried out under different conditions and controlled according to each process. In the curing process described above, when the differential pressure P measured by the differential pressure sensor is P > 0, and the offset value P3 set in the differential pressure sensor is P > P3, A carbonate curing system for hydraulic curing bodies, comprising mode 3, in which the valve at the discharge section of the carbonate curing tank is opened to discharge the gas to the outside of the carbonate curing tank, and then the valve is closed.

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