Low-temperature compressed air supply system and low-temperature compressed air supply method

Abstract

To provide a low temperature compressed air supply device system and a low temperature compressed air supply method capable of reducing energy consumption for system operation by appropriately coping with changes in ambient environmental conditions such as a meteorological condition and a product air use environmental condition.SOLUTION: A low temperature compressed air supply device system includes: a heatless dryer 1 for dehumidifying compressed air by using two absorption cylinders filled with an absorption agent which are switched alternately, and discharging dry compressed air; a drying and cooling system part 200 including a first cooler 2 for cooling dry compressed air supplied from the heatless dryer 1 and a second cooler 3 for further cooling the dry compressed air cooled by the first cooler 2 and supplied from the first cooler; and a control device 50 for executing control to stop the first cooler 2 and controlling switching time of the heatless dryer 1 when a temperature and a dew point related to the supplied compressed air are lower than criteria or when a flow rate discharged as product air becomes lower than a criterion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a low-temperature compressed air supply device system and a low-temperature compressed air supply method that dehumidify and cool compressed air supplied from an air compressor and discharge dry low-temperature air.

Background Art

[0002] The applicant has previously proposed a cold air supply device having a refrigerator that cools compressed air and a cold air blowing unit that blows the compressed air cooled by this refrigerator toward a cooling target, the cold air supply device being characterized by having flow rate adjusting means for restricting the flow rate of the cold air blown out from the cold air blowing unit to a standby operation flow rate that is zero or less than the flow rate during normal operation during standby operation (see Patent Document 2). According to this cold air supply device (low-temperature compressed air supply device system), it is possible to reduce the wasted time of the processing operation by shortening the pre-cooling preparation time associated with a temporary stop.

[0003] The applicant has also previously disclosed a compressed air cooling device for producing cooled compressed air for use in cooling a workpiece or tool of a machine tool, the device comprising: a first cooling circuit including a first cooler for cooling compressed air and a first refrigerant circulation circuit for circulating a first refrigerant through the first cooler; a second cooling circuit including a second cooler for cooling compressed air supplied via the first cooler and a second refrigerant circulation circuit for circulating a second refrigerant through the second cooler; and a switching control means for simultaneously using or selectively using the first cooling circuit and the second cooling circuit to cool the compressed air, the first refrigerant having a boiling point higher than that of the second refrigerant, The switching control means, based on a preset temperature of the cooled compressed air after being cooled by the second cooler, an inlet temperature which is the temperature of the compressed air before being cooled by the first cooler, and a preset switching control temperature, cools the compressed air using only the second cooling circuit when the preset temperature is lower than the switching control temperature, cools the compressed air using both the first and second cooling circuits when the inlet temperature is equal to or higher than the switching control temperature, and cools the compressed air using only the first cooling circuit when the preset temperature is equal to or higher than the switching control temperature. This provides a compressed air cooling device (low-temperature compressed air supply system) with good cooling efficiency over the entire cooling temperature range and low power consumption.

[0004] Conventionally, low-temperature compressed air supply systems have used an adsorption-type dehumidifier (also called a "heatless dryer") as a component thereof. In this heatless dryer, two adsorption columns (hereinafter also referred to as "adsorption towers") filled with adsorbents such as activated alumina, silica gel, synthetic zeolite, or lithium chloride are provided to continuously discharge and supply dry gas (e.g., air). Moist compressed air is introduced into one of the adsorption towers to perform adsorption drying, and the resulting dry air is supplied to a specified supply destination. At the same time, a part of the obtained dry air is introduced into the other adsorption tower, where moisture is desorbed from the adsorbent whose moisture absorption capacity has been reduced by absorbing moisture in the previous drying process, and this moisture is purged from the adsorption tower to regenerate the adsorbent. In this regeneration process, generally, about 10% of the obtained dry air is released into the atmosphere. The drying process of the compressed air in one of the adsorption towers and the regeneration process of the adsorbent in the other adsorption tower are performed simultaneously in parallel. In addition, these drying and regeneration processes are performed alternately between the two adsorption towers. For example, a switching valve connected to both adsorption towers is switched every time a specified time has elapsed. This allows the dry air to be continuously supplied to a specified supply destination as product air. This two-column method for adjusting the composition of compressed gas is also called the pressure swing method.

[0005] In such a gas component adjusting device that uses an adsorbent, if the device is not properly stopped when the device is stopped, the device may not be able to continue to operate properly when the device is restarted. In response to this, for example, a continuous supply method for dehumidifying compressed gas includes a drying step in which compressed gas is introduced into one of two adsorption towers filled with an adsorbent, where moisture in the compressed gas is adsorbed and dehumidified to discharge dry gas, and a regeneration step in which a part of the compressed gas dried in the drying step is introduced into the other adsorption tower which adsorbed and dehumidified the moisture in the compressed gas in the previous step, where moisture is desorbed from the adsorbent whose adsorption capacity has decreased and the adsorbent is discharged, thereby regenerating the adsorbent. The drying step and the regeneration step are performed substantially alternately between the two adsorption towers, thereby continuously discharging dry gas. The present applicant has proposed a continuous supply method for dehumidifying compressed gas (see Patent Document 1), which is characterized in that in the regeneration process, exhaust is controlled by operating an exhaust valve provided for each adsorption tower and driven to open and close by dried compressed gas supplied from the adsorption tower, and when the pressure of the compressed gas used to drive the exhaust valves to open and close falls below a preset value, both exhaust valves applied to each adsorption tower are closed so that exhaust in the regeneration process is stopped for both adsorption towers, and then operation of the entire apparatus is stopped. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3217030 (Claim 1) [Patent Document 2] Patent No. 3518860 (Claim 1) [Patent Document 3] Patent No. 4351174 (Claim 1) Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the low-temperature compressed air supply system and the low-temperature compressed air supply method is that the conventional system was unable to respond appropriately to changes in external environmental conditions such as weather conditions and the environmental conditions in which the product air is used, resulting in unnecessary energy consumption for the operation of the system. For example, even if the compressed air intake conditions for the low-temperature compressed air supply system change, there has been no reasonable proposal for appropriately changing the operating conditions in response to the change and reducing energy consumption.

[0008] Therefore, an object of the present invention is to provide a low-temperature compressed air supply system and a low-temperature compressed air supply method that can appropriately respond to changes in external environmental conditions, such as weather conditions and the environmental conditions under which the product air is used, and that can reduce energy consumption for operating the system. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention has the following configuration. According to one embodiment of the low-temperature compressed air supply system of the present invention, there is provided a low-temperature compressed air supply system that dehumidifies and cools compressed air supplied from an air compressor to discharge dry low-temperature air, the system including a heatless dryer which is an adsorption-type dehumidifier that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified dry compressed air, a drying and cooling system unit including a first cooler that cools the dry compressed air supplied from the heatless dryer, and a second cooler that further cools the cooled dry compressed air supplied from the first cooler, and a control device that controls to stop or reduce cooling by the first cooler when the temperature of the compressed air supplied to the drying and cooling system unit is lower than a reference temperature or when the flow rate of the compressed air discharged as product air falls below the reference flow rate.

[0010] According to one embodiment of the low-temperature compressed air supply system of the present invention, there is provided a low-temperature compressed air supply system that dehumidifies and cools compressed air supplied from an air compressor to discharge dry low-temperature air, the system including a heatless dryer which is an adsorption-type dehumidifier that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified dry compressed air, a drying and cooling system unit including a first cooler that cools the dry compressed air supplied from the heatless dryer, and a second cooler that further cools the cooled dry compressed air supplied from the first cooler, and a control device that controls to extend the interval between switching times for the two adsorption cylinders of the heatless dryer when the dew point of the compressed air supplied to the drying and cooling system unit is lower than a reference dew point or when the flow rate of the compressed air discharged as product air falls below the reference flow rate.

[0011] In addition, according to one embodiment of the low-temperature compressed air supply device system of the present invention, a temperature sensor for detecting the temperature and a dew point sensor for detecting the dew point can be installed on the side of the inlet section that supplies compressed air to the drying cooling system section.

[0012] In addition, according to one embodiment of the low-temperature compressed air supply device system of the present invention, a flow rate sensor for detecting a flow rate can be installed on the side of the inlet part that supplies dry compressed air to the second cooler.

[0013] According to one embodiment of the low-temperature compressed air supply method of the present invention, there is provided a low-temperature compressed air supply method for dehumidifying and cooling compressed air supplied from an air compressor to discharge dry low-temperature air, the method comprising: a heatless dryer which is an adsorption-type dehumidification device which dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified dry compressed air; a first cooler which cools the dry compressed air supplied from the heatless dryer; and a second cooler which further cools the cooled dry compressed air supplied from the first cooler, wherein the method is characterized in that, in a case where the temperature of the compressed air supplied to the drying cooling system is lower than a reference temperature or the flow rate of the compressed air discharged as product air falls below a reference flow rate, cooling by the first cooler is stopped or reduced.

[0014] According to one embodiment of the low-temperature compressed air supply method of the present invention, there is provided a low-temperature compressed air supply method for dehumidifying and cooling compressed air supplied from an air compressor to discharge dry low-temperature air, the method comprising: a heatless dryer which is an adsorption-type dehumidification device which dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified dry compressed air; a first cooler which cools the dry compressed air supplied from the heatless dryer; and a second cooler which further cools the cooled dry compressed air supplied from the first cooler; dew point is the standard dew point The present invention is characterized in that, when the flow rate of the compressed air discharged as product air is lower than a reference flow rate, the interval between switching times for the two adsorption tubes of the heatless dryer is extended. Effect of the Invention

[0015] The low-temperature compressed air supply system and low-temperature compressed air supply method of the present invention have the particularly advantageous effect of being able to appropriately respond to changes in external environmental conditions, such as weather conditions and the environmental conditions under which the product air is used, and to reduce energy consumption for operating the system. [Brief description of the drawings]

[0016] [Figure 1] 1 is a circuit diagram showing an example of a low-temperature compressed air supply system according to the present invention. [Diagram 2] FIG. 1 is a circuit diagram showing an example of a heatless dryer according to the present invention. [Diagram 3] 2 is a time chart illustrating an embodiment of the operation of the heatless dryer of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, examples of a low-temperature compressed air supply system and a low-temperature compressed air supply method according to the present invention will be described in detail with reference to the accompanying drawings (FIGS. 1 to 3). The low-temperature compressed air supply system dehumidifies and cools compressed air supplied from an air compressor, and discharges dried low-temperature air.

[0018] First, an invention for controlling the drying and cooling system section 200 in order to reduce energy consumption (hereinafter referred to as "energy saving") in this low-temperature compressed air supply device system will be described with reference to FIG.

[0019] The low-temperature compressed air supply system of the present invention is basically configured to include a heatless dryer 1, which is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders 10, 20 (see Figure 2) filled with adsorbent and continuously discharges the dehumidified dry compressed air, and a drying and cooling system section 200 that includes a first cooler 2 that cools the dry compressed air supplied from the heatless dryer 1, and a second cooler 3 that further cools the cooled dry compressed air supplied from the first cooler 2.

[0020] The first configuration for energy saving includes a control device 50 that controls the cooling by the first cooler to be stopped or reduced when the temperature of the compressed air supplied to the drying and cooling system section 200 is lower than a reference temperature, or when the flow rate of the compressed air discharged as product air falls below a reference flow rate.

[0021] The low-temperature compressed air supply system and low-temperature compressed air supply method according to the present invention can appropriately respond to changes in external environmental conditions, such as weather conditions and the environmental conditions under which the product air is used, and can reduce energy consumption for operating the system. That is, if the inlet air temperature is low, it is determined that the sensible heat load is low, and if the flow rate is low, it is determined that the load is low, and energy can be saved by stopping or reducing the operation of the first cooler.

[0022] In addition, a compressed air supply source 100 that supplies compressed air to the inlet portion is connected to the drying cooling system section 200 of the present invention, and a cooling water source 300 can be connected to the first cooler 2 and the second cooler 3 provided in the drying cooling system section 200 as an example of a means for cooling the respective condensers 2b, 3b.

[0023] The compressed air supply source 100 may be, for example, a compressor that generates compressed air, a compressed air dehumidifier that dehumidifies the compressed air by condensing the moisture contained in the compressed air and discharging it as drain, or an air pressure tank as components. In addition, the ultra-low temperature dried air, which is the product air generated by this low temperature compressed air supply device system, is configured to be discharged from the drying and cooling system section 200 so as to be supplied to the low temperature compressed air utilization equipment 400.

[0024] In addition, the first cooler 2 and the second cooler 3 in this embodiment are devices that perform cooling by a refrigeration cycle, and the compressed air is cooled by the first heat exchanger 2a and the second heat exchanger 3a, and the compressed air at an ultra-low temperature adjusted to, for example, -35°C can be supplied to the low-temperature compressed air utilization facility 400. In this embodiment, the cooling water 9 is introduced from an external cooling water source 300, and the first water-cooled condenser 2b of the first cooler 2 and the second water-cooled condenser 3b of the second cooler 3 are cooled by the water-cooled refrigeration cycle system. Of course, the coolers 2 and 3 using this refrigeration cycle can be an air-cooled refrigeration cycle system. In this embodiment, 3c is a dew point sensor, which is a component of the second cooler 3 and is provided to slightly purge air in order to measure the dew point. Furthermore, 3d is an air purge valve which is installed so as to purge appropriately when there is an excess of low-temperature compressed air, which is the product air, supplied to the low-temperature compressed air utilization facility 400 side.

[0025] Next, as a second configuration for energy saving, a control device 50 is provided that controls the switching time interval for the two adsorption tubes 10, 20 of the heatless dryer 1 to be extended when the dew point of the compressed air supplied to the drying and cooling system section 200 is lower than a reference dew point, or when the flow rate of the compressed air discharged as product air falls below the reference flow rate.

[0026] The low-temperature compressed air supply system and method according to the present invention can appropriately respond to changes in external environmental conditions, such as weather conditions and product air use conditions, and reduce energy consumption for system operation. That is, if the inlet dew point is low, it is determined that the moisture load at the system inlet is low, and if the flow rate is low, it is determined that the load is low, and energy can be saved by extending the switching time of the heatless dryer. That is, by extending the switching time of the heatless dryer, it is possible to reduce the amount of compressed air discharged mainly by purging in the adsorbent regeneration process, resulting in energy savings.

[0027] In this embodiment, a temperature sensor for detecting temperature and a dew point sensor for detecting dew point (temperature dew point sensor 6) are installed on the side of the air inlet that supplies compressed air to the drying and cooling system section 200. This allows the condition of the compressed air supplied to the drying and cooling system section 200 to be properly confirmed, and allows the components of the drying and cooling system section 200 to be appropriately controlled so as to properly respond to changes in the outside world, such as weather conditions, and to reduce energy consumption for operating the system, as described above. In this embodiment, the control device 50 receives information from the temperature dew point sensor 6 installed as described above, and the control device transmits operation commands to each device in accordance with preset conditions, thereby enabling energy-saving operation.

[0028] In this embodiment, the flow sensor 7 for detecting the flow rate is installed on the side of the air inlet that supplies dry compressed air to the second cooler. As a result, the flow sensor 7 is installed on the most downstream side of the system within a range that satisfies the cold resistance performance of a normal flow sensor 7. Therefore, the flow rate of the product air that is ultimately required can be measured under better conditions, and appropriate control can be performed based on the measurement data. In this embodiment, the control device 50 receives information from the flow sensor 7 installed as described above, and the control device 50 transmits operation commands to each device according to preset conditions, thereby enabling energy-saving operation.

[0029] Next, with reference to FIG. 1 , an invention will be described regarding a low-temperature compressed air supply system and a low-temperature compressed air supply method related to the present invention, which controls the drying and cooling system section 200 in order to continue operating and protect the low-temperature compressed air supply system when the flow rate of the compressed air flowing through the drying and cooling system section 200 exceeds the rated flow rate.

[0030] The low-temperature compressed air supply system for dealing with cases where the rated flow rate is exceeded also has a basic configuration that includes a heatless dryer 1, which is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders 10, 20 (see Figure 2) filled with adsorbent and continuously discharges the dehumidified, dry compressed air, a first cooler 2 that cools the dry compressed air supplied from the heatless dryer 1, and a second cooler 3 that further cools the cooled, dry compressed air supplied from the first cooler 2.

[0031] The first configuration for continuing operation and protecting the low-temperature compressed air supply system includes a flow control valve 8 that adjusts the flow rate of the compressed air flowing through the drying cooling system section 200 to the rated flow rate when the flow rate exceeds the rated flow rate, and a control device 50 that controls the flow control valve 8.

[0032] According to this low-temperature compressed air supply system and low-temperature compressed air supply method, it is possible to protect the system while continuing operation even if the compressed air flow rate exceeds the rated flow rate due to a sudden change in the intake air conditions, load change, etc. In other words, by adjusting the flow control valve so that the flow rate is the rated flow rate when the flow rate exceeds the rated flow rate, the system can continue operation without an alarm being issued and the second cooler 3, which is the ultra-low-temperature compressed air cooling device, can be prevented from being put into an overloaded operating state, and damage to the filter elements due to an increase in the differential pressure of the filters (the first filter 4 and the second filter 5, etc.) when the air volume increases can be prevented.

[0033] In this embodiment, the flow control valve 8 is installed on the side of the discharge portion that discharges the product air from the second cooler 3. This allows the flow control valve 8 to be located immediately before the portion that is connected to the low-temperature compressed air utilization facility 400 that supplies the product air, making it possible to more accurately control the flow rate of the product air.

[0034] And as a second configuration for the continuous operation and protection of the low-temperature compressed air supply device system, when the flow rate of the compressed air flowing through the dry cooling system unit exceeds the rated flow rate, a control device is provided to control the set temperature of the second cooler to increase.

[0035] According to this low-temperature compressed air supply device system and the low-temperature compressed air supply method, even when the compressed air flow rate increases due to sudden fluctuations in intake conditions or load fluctuations, etc., exceeding the rated flow rate, the operation can continue. That is, in this invention, when the load of the heatless dryer 1 and the first cooler 2 increases with the increase in the flow rate, the inlet dew point of the second cooler 3 rises due to the increase in the load of the heatless dryer 1. In order to prevent freezing of the second heat exchanger 3a built in the second cooler 3, the set temperature is increased to control the outlet temperature above the dew point temperature. According to this, even when the flow rate exceeds the rated flow rate, by automatically changing the set temperature of the second cooler 3, which is an ultra-low temperature compressed air cooling device, according to the measured flow rate, the system can continue to operate without alarm stopping. Note that this control is executed on the side of the low-temperature compressed air utilization facility 400 within a limited allowable range, and it functions effectively when an operable range that is not the optimal condition is set, and the operation can be continued.

[0036] And as a third configuration for the continuous operation and protection of the low-temperature compressed air supply device system, when the flow rate of the compressed air flowing through the dry cooling system unit exceeds the rated flow rate at the switching timing related to the two adsorption cylinders 10 and 20 of the heatless dryer, a control device 50 is provided to control the switching timing related to the two adsorption cylinders 10 and 20 of the heatless dryer to be delayed by a certain time.

[0037] According to this low-temperature compressed air supply system and low-temperature compressed air supply method, even if the compressed air flow rate exceeds the rated flow rate due to a sudden change in the intake air conditions or load change, the system can be protected while continuing operation. That is, if the flow rate exceeds the rated flow rate at the timing of switching the adsorption columns 10 and 20 of the heatless dryer 1, the switching timing of the heatless dryer 1 is delayed for a certain time, so that the system can continue operation without issuing an alarm and the flow rate can be prevented from increasing at the timing of switching the adsorption columns 10 and 20, and damage to the filter elements due to an increase in the pressure difference between the filters (the first filter 4 and the second filter 5, etc.) when the air volume increases can be prevented. This also ensures that the second filter 5 functions reliably, and prevents leakage of the adsorbent from the heatless dryer 1.

[0038] In the above embodiment in which the switching timing of the heatless dryer 1 is delayed for a certain time, if the flow rate still exceeds the rated flow rate after the certain time has elapsed, and there are no serious problems with other conditions, switching of the adsorption columns 10, 20 is performed. This is because the dew point would rise if switching of the adsorption columns 10, 20 was not performed.

[0039] The phenomenon of the flow rate increasing at the timing of switching between the two adsorption columns 10, 20 is due to a primary increase in the amount of air discharged as product air, as shown in steps (1), (3), and (1)' in Figure 3, at the end of the adsorbent pressurization process when pressurization is completed and before switching occurs in each adsorption column 10 or 20, as there is no air to be purged and exhausted or used for pressurization. Therefore, delaying the switching timing of the heatless dryer 1 by a certain period of time means extending a process that includes an exhaust process in which exhaust is performed by purging in either the adsorption column 10 or 20, as shown in steps (2), (4), or (4)' in Figure 3, and delaying the switching timing by a certain period of time.

[0040] Next, an example of the form of a heatless dryer (compressed gas component adjustment device) of the contents of the application in Japanese Patent Application No. 2021-144449 that can be applied to the present invention will be described in detail with reference to Figures 2 and 3. The compressed gas component adjustment device according to the present invention adjusts the gas components of a compressed gas by alternately using two adsorption cylinders 10 and 20 filled with an adsorbent, and continuously discharges the adjusted gas with the adjusted gas components, and has the following configuration.

[0041] This compressed gas component adjustment device is provided with a first adsorption column 10 and a second adsorption column 20 filled with an adsorbent that adsorbs a required component of the introduced compressed gas. In FIG. 2, the first adsorption column 10 is indicated as "CLM A" and the second adsorption column 20 is indicated as "CLM B". The adsorbent in this embodiment adsorbs moisture in the air and discharges dry air as product air, and is an adsorption-type dehumidification device as described in the Background Art section, but the present invention is not limited to this, and it goes without saying that an adsorbent that can adsorb other gas components other than moisture (water vapor) can be used as appropriate. Accordingly, the present invention can be suitably applied as a compressed gas component adjustment device that functions to remove a required gas component and increase the concentration of the required gas component.

[0042] In addition, in this embodiment, as shown in FIG. 2 , the gas passages include a first gas supply passage 11 that guides compressed gas to the first adsorption column 10, and a second gas supply passage 21 that guides compressed gas to the second adsorption column 20, a first discharge passage 13 that discharges regulated gas from the first adsorption column 10, and a second discharge passage 23 that discharges regulated gas from the second adsorption column 20, an inter-adsorption column connection passage 33 that connects the first adsorption column 10 and the second adsorption column 20, a first exhaust passage 15 through which a portion of the regulated gas regulated in the second adsorption column 20 is guided via the inter-adsorption column connection passage 33 to the first adsorption column 10 to desorb and purge required components from the adsorbent and exhaust the gas so as to regenerate the adsorbent, and a second exhaust passage 25 through which a portion of the regulated gas regulated in the first adsorption column 10 is guided via the inter-adsorption column connection passage 33 to the second adsorption column 20 to desorb and purge required components from the adsorbent and exhaust the gas so as to regenerate the adsorbent.

[0043] 2, an orifice 34 is provided in the inter-adsorption cylinder connection path 33, and this orifice 34 acts to obtain a predetermined constant flow rate by applying a predetermined constant pressure. Therefore, in this embodiment, when the first exhaust passage 15 or the second exhaust passage 25 is opened and the first adsorption cylinder 10 or the second adsorption cylinder 20 is opened to the atmosphere, the amount of air passing through the orifice 34 is automatically controlled to a constant flow rate due to the pressure difference between the inside of the first adsorption cylinder 10 or the second adsorption cylinder 20 that is opened to the atmosphere and the supplied compressed gas.

[0044] In this embodiment, as shown in Fig. 2, components of the valve mechanism of the "switching valve (see Fig. 3)" which opens and closes the supply passages 11, 12 of the above-mentioned gas passages include a first supply valve 12 which opens and closes the first supply passage 11, a second supply valve 22 which opens and closes the second supply passage 21, and supply valve opening and closing means 30 which operates to switch between opening and closing the first supply valve 12 and the second supply valve 22. In the embodiment shown in Fig. 2, the first supply valve 12 and the second supply valve 22 are constituted by control valves (CTV), and the supply valve opening and closing means 30 is constituted by a pilot valve (PV1).

[0045] 2, the present embodiment includes, as components of a valve mechanism of an "exhaust valve (see FIG. 3)" that opens and closes the exhaust passages 15, 25 of the above-mentioned gas passages, a first exhaust valve 16 that opens and closes the first exhaust passage 15, a second exhaust valve 26 that opens and closes the second exhaust passage 25, a first exhaust valve opening and closing device 17 that operates to open and close the first exhaust valve 16, and a second exhaust valve opening and closing device 27 that operates to open and close the second exhaust valve 26. In the embodiment shown in FIG. 2, the first exhaust valve 16 and the second exhaust valve 26 are configured as exhaust valves (EXV), and the exhaust valve opening and closing means is configured by two pilot valves (PV2, PV3) arranged as the first exhaust valve opening and closing device 17 and the second exhaust valve opening and closing device 27.

[0046] In addition, the pilot valve (PV1) constituting the intake valve opening / closing means 30 in this embodiment, and the two pilot valves (PV2, PV3) constituting the first exhaust valve opening / closing device 17 and the second exhaust valve opening / closing device 27 are electromagnetically controlled valves, and operate as described in Patent Document 3. They are arranged so that the compressed gas supplied from the two adsorption cylinders 10, 20 operates the above-mentioned control valve (CTV) and exhaust valve (EXV) to perform the above-mentioned switching process.

[0047] 2, a first pressure sensor 45 for monitoring the pressure in the first adsorption column 10 and a second pressure sensor 46 for monitoring the pressure in the second adsorption column 20 are provided. The first pressure sensor 45 (PS1) in this embodiment is attached to a pipe (air passage) on the downstream side, where the conditioned gas (dry air in this embodiment) of the first adsorption column 10 is discharged, before the orifice 34 of the adsorption column connection path 33, and is provided to measure and detect the pressure of the first adsorption column 10 and output the detected pressure information to the control device 50 described later. The second pressure sensor 46 (PS2) in this embodiment is attached to a pipe (air passage) on the downstream side, where the conditioned gas (dry air in this embodiment) of the second adsorption column 20 is discharged, before the orifice 34 of the adsorption column connection path 33, and is provided to measure and detect the pressure of the second adsorption column 20 and output the detected pressure information to the control device 50 described later.

[0048] In this embodiment, the control device 50 receives detected pressure information obtained by the first pressure sensor 45 and / or the second pressure sensor 46, and compares the detected pressure information with a preset set pressure based on a preset set time, and when the required conditions are reached, outputs a control signal or a warning signal to operate the intake valve opening / closing means 30 and the exhaust valve opening / closing means (first exhaust valve opening / closing device 17 and second exhaust valve opening / closing device 27).

[0049] By being configured as described above, the compressed gas component adjustment apparatus of the present invention has the particularly advantageous effect of being able to monitor the pressure changes inside the two adsorption columns 10, 20 used in the pressure swing method in relation to the elapsed time, and to more appropriately manage the operation of the apparatus that carries out the process related to the adjustment of the gas component of the compressed gas.

[0050] As shown in FIG. 2, the present embodiment includes the following configuration in addition to the above configuration. Reference numeral 14 denotes a check valve (CKV(1)), which is installed so as to prevent the discharged regulated gas (dry air in this embodiment) from flowing back. Reference numeral 42 denotes a check valve (CKV(2)), which is installed so as to prevent the compressed gas supplied from the downstream of the two adsorption cylinders 10, 20 to the pilot valve (PV1) and the two pilot valves (PV2, PV3) for control from flowing back. In FIG. 2, AF denotes an air filter, IF denotes an inlet filter, and OF denotes an outlet filter. In FIG. 2, SLC denotes a silencer, which serves as the exhaust port of the exhaust valve (EXV), and is arranged to reduce exhaust noise. Furthermore, MS denotes a temperature and humidity sensor.

[0051] Next, a specific embodiment of the control configuration of the control device 50 will be described with reference to FIG. In this embodiment, as shown in FIG. 3, the control device 50 closes the first exhaust valve 16 or the second exhaust valve 26 to increase the pressure in the first adsorption column 10 or the second adsorption column 20, and sets a first pressure increase set time ( seconds) and its first boost setting time ( sec) longer than the second boost setting time ( <c>There are two settings:

[0052] The time (X seconds) shown in FIG. 3 is the time it takes to actually reach the set pressure (in this embodiment, the pressure difference between the two adsorption columns 10 and 20 is, for example, 0 (±0.05) MPa or Δp), and is the first set pressure increase time (< / c> When it is detected by the detected pressure information of the first pressure sensor 45 and / or the second pressure sensor 46 that the boost set pressure is reached within the first boost set time ( A control signal is output from the control device 50 to operate the intake valve opening and closing means 30 and the exhaust valve opening and closing means (the first exhaust valve opening and closing device 17 or the second exhaust valve opening and closing device 27) to switch between intake and exhaust. Note that this boost set pressure may be a differential pressure calculated from the detected pressure information of the first pressure sensor 45 and the second pressure sensor 46, or may be a pressure (Δp) that is set individually for the detected pressure information of the first pressure sensor 45 or the second pressure sensor 46, for example, when the supply pressure supplied to the compressed gas component adjuster is stable. An example of operation using this is, for example, the time chart in FIG. 3, when the actual elapsed time (X seconds) in the second adsorption column 20 (column B) at the time of transition from step (1) to (2) reaches the first boost set time ( When the time t1 becomes the same as the time t2 (seconds), the intake valve opening / closing means 30 opens the second intake valve 22 to switch the intake air from the first adsorption column 10 (column A) to column B 20, thereby starting the adsorption process in column B 20, and in column A 10, the first exhaust valve opening / closing device 17 opens the first exhaust valve 16 to start the exhaust process.

[0053] In addition, the first boost setting time ( sec) to the second boost setting time ( <c> When it is detected by the detected pressure information of the first pressure sensor 45 and / or the second pressure sensor 46 that the boost set pressure (differential pressure of 0 (±0.05) MPa, or Δp) has been reached within 30 seconds, a control signal is output by the control device 50 to operate the intake valve opening and closing means 30 and the first exhaust valve opening and closing device 17 or the second exhaust valve opening and closing device 27 at the time of detection to switch between intake and exhaust. An example of operation based on this is, for example, in the time chart of FIG. 3, when the actual elapsed time (X seconds) in the B cylinder 20 at the time of transition from process (1)' to (2)' reaches the first boost set time (< / c> If the time t1 is longer than X seconds, then at that point (X seconds), the second air intake valve 22 is opened by the air intake valve opening / closing means 30 to switch the air intake from cylinder A 10 to cylinder B 20, thereby starting the adsorption process in cylinder B 20, and in cylinder A 10, the first exhaust valve opening / closing device 17 opens the first exhaust valve 16 to start the exhaust process. Note that in the time chart of Fig. 3, when moving from process (3) to (4), the operations of cylinder A 10 and cylinder B 20 are reversed, but the same switching operation as above is performed.

[0054] Furthermore, the second boost setting time ( <c>If it is not detected by the detected pressure information of the first pressure sensor 45 and / or the second pressure sensor 46 that the pressure increase setting pressure (differential pressure 0 (±0.05) MPa, or Δp) is reached within the second pressure increase setting time ( <c>sec), the control device 50 outputs a control signal to forcibly operate the intake valve opening / closing means 30 and the first exhaust valve opening / closing device 17 or the second exhaust valve opening / closing device 27 to switch between intake and exhaust. An example of an operation based on this is, for example, in the time chart of FIG. 3, when the second boost setting time ( <c>If the set pressure (Δp) is not reached within 1 second, the <c>At time t10 seconds, the first air intake valve 12 is opened by the air intake valve opening / closing means 30 to switch the air intake from cylinder B 20 to cylinder A 10, thereby starting the adsorption process in cylinder A 10, and in cylinder B 20, the second exhaust valve opening / closing device 27 opens the second exhaust valve 26 to start the exhaust process.

[0055] The above switching operation in the pressure increase process enables smooth switching as described above, and prevents the adsorbent from being powdered (deteriorated) due to pressure fluctuations and valve failures.

[0056] Furthermore, in this embodiment, the control device 50 determines a preset pressure drop set time ( The pressure drop set pressure (Δp) is compared with the detected pressure information from first pressure sensor 45 or second pressure sensor 46, which is provided to monitor the pressure in first adsorption column 10 or second adsorption column 20, and an alarm signal is output to issue an alarm if the pressure in first adsorption column 10 or second adsorption column 20 has not dropped to the pressure drop set pressure (Δp) even after 100 seconds have passed.

[0057] As an example of the operation by this, for example, in the time chart of FIG. 3, as shown in step (4)′, in the B column 20, the pressure drop setting time ( If the actual pressure reduction time (Y seconds) does not reach the set pressure reduction pressure (Δp) even after the set pressure reduction time ( When the time t1 is longer than 100 s, an alarm signal for issuing an alarm is output by the control device 50. This makes it possible to improve reliability and operating efficiency as described above.

[0058] According to the compressed gas component adjustment device (heatless dryer) described above, by applying the control method using the control device 50, it is possible to control the low-temperature compressed air supply system shown in Figure 1 to extend the switching time interval between the two adsorption columns 10, 20 of the heatless dryer 1, or to delay the switching timing between the two adsorption columns 10, 20 of the heatless dryer 1 by a certain period of time.

[0059] Although the present invention has been described above in various preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. [Explanation of symbols]

[0060] 1. Heatless dryer 2. First Cooler 2a First heat exchanger 2b First water-cooled condenser 3 Second Cooler 3a Second heat exchanger 3b Second water-cooled condenser 3c Dew Point Sensor 3d Air Purge Valve 4. First Filter 5. Second Filter 6 Temperature dew point sensor 7 Flow Sensor 8 Flow Control Valve 9 Cooling water 10 First adsorption cylinder (A cylinder) 11 First air supply passage 12 First air intake valve 13 1st discharge passage 14 Check valve (CKV(1)) 15 First exhaust passage 16 First exhaust valve 17 First exhaust valve opening / closing device (pilot valve (PV2)) 20 Second adsorption cylinder (B cylinder) 21 Second air supply passage 22 Second air intake valve 23 2nd discharge passage 25 Second exhaust passage 26 Second exhaust valve 27 Second exhaust valve opening and closing device (pilot valve (PV3)) 30 Air supply valve opening / closing means (pilot valve (PV1)) 33 Adsorption cylinder connection path 34 Orifice 42 Check valve (CKV(2)) 45 First pressure sensor 46 Second pressure sensor 50 Control device 100 Compressed Air Supply Source 200 Drying and Cooling System Section 300 Cooling water source 400 Low-temperature compressed air equipment < / c> < / c> < / c> < / c>

Claims

1. A low-temperature compressed air supply system that dehumidifies and cools compressed air supplied from an air compressor to discharge dry low-temperature air, A heatless dryer is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified, dry compressed air. a first cooler for cooling the dry compressed air supplied from the heatless dryer; a second cooler that further cools the cooled, dry compressed air supplied from the first cooler; A low-temperature compressed air supply system characterized by comprising a control device that controls the cooling by the first cooler to be stopped or reduced when the temperature of the compressed air supplied to the drying cooling system section is lower than a reference temperature, or when the flow rate of the compressed air discharged as product air falls below a reference flow rate.

2. A low-temperature compressed air supply system that dehumidifies and cools compressed air supplied from an air compressor to discharge dry low-temperature air, A heatless dryer is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified, dry compressed air. a first cooler for cooling the dry compressed air supplied from the heatless dryer; a second cooler that further cools the cooled, dry compressed air supplied from the first cooler; A low-temperature compressed air supply system characterized by comprising a control device that controls the switching time interval between the two adsorption cylinders of the heatless dryer to be extended when the dew point of the compressed air supplied to the drying and cooling system section is lower than a reference dew point, or when the flow rate of the compressed air discharged as product air falls below a reference flow rate.

3. 3. The low-temperature compressed air supply system according to claim 1, wherein a temperature sensor for detecting a temperature and a dew point sensor for detecting a dew point are installed on the side of an intake section that supplies compressed air to the drying cooling system section.

4. 3. The low-temperature compressed air supply system according to claim 1, wherein a flow rate sensor for detecting a flow rate is installed on the side of an inlet portion for supplying dry compressed air to the second cooler.

5. A method for supplying low-temperature compressed air, comprising the steps of: dehumidifying and cooling compressed air supplied from an air compressor to discharge dry low-temperature air, A heatless dryer is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified, dry compressed air. a first cooler for cooling the dry compressed air supplied from the heatless dryer; a second cooler that further cools the cooled, dry compressed air supplied from the first cooler, A method for supplying low-temperature compressed air, characterized in that cooling by the first cooler is stopped or reduced when the temperature of the compressed air supplied to the drying and cooling system section is lower than a reference temperature, or when the flow rate of the compressed air discharged as product air falls below a reference flow rate.

6. A method for supplying low-temperature compressed air, comprising the steps of: dehumidifying and cooling compressed air supplied from an air compressor to discharge dry low-temperature air, A heatless dryer is an adsorption-type dehumidification device that dehumidifies compressed air by alternately switching between two adsorption cylinders filled with an adsorbent and continuously discharges the dehumidified, dry compressed air. a first cooler for cooling the dry compressed air supplied from the heatless dryer; a second cooler that further cools the cooled, dry compressed air supplied from the first cooler, A method for supplying low-temperature compressed air, characterized in that when the dew point of the compressed air supplied to the drying and cooling system section is lower than a reference dew point, or when the flow rate of the compressed air discharged as product air falls below a reference flow rate, the switching time interval between the two adsorption cylinders of the heatless dryer is extended.

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