JP4346558B2 - Method for continuous supply in dehumidification of compressed gas and dehumidifier for compressed gas - Google Patents

Description

  The present invention relates to a continuous supply method and a dehumidifier for compressed gas in dehumidification of compressed gas using an adsorbent.

Conventionally, adsorption type dehumidifiers (also referred to as “heatless dryers”) continuously discharge and supply dry gas (for example, air), so adsorption of activated alumina, silica gel, synthetic zeolite, lithium chloride, etc. Two adsorption towers filled with the agent are provided.
Wet compressed air is introduced into one adsorption tower to perform adsorption drying, and the obtained dry air is supplied to a predetermined supply destination. At the same time, a part of the obtained dry air is guided to the other adsorption tower, and moisture is desorbed from the adsorbent with reduced moisture absorption capacity in the previous drying process, and this moisture is purged from the adsorption tower. Then, the adsorbent is regenerated. In this regeneration step, generally, about 20% of the obtained dry air is released into the atmosphere.
The drying process of the compressed air in one adsorption tower and the regeneration process of the adsorbent in the other adsorption tower are simultaneously performed in parallel. These drying and regeneration steps are alternately performed between the two adsorption towers. For example, the switching valve connected to both adsorption towers is switched every predetermined time. Thereby, dry air can be continuously supplied to a predetermined supply destination as product air.

In such a gas adjusting device using an adsorbent, if the operation is not stopped properly at the time of operation stop, it may not be possible to continue a suitable operation at the time of operation restart.
For this reason, in a two-column system that uses an adsorbent to concentrate oxygen from the air by the pressure swing method, the operation is started and stopped to make the oxygen concentration of the product oxygen-enriched gas extremely fast. In operation control including operation, both adsorption towers must be pressurized at a pressure higher than the atmospheric pressure specified in advance, and one of these adsorption towers must be stopped after the regeneration process is complete, There has been proposed a control method for an on-off valve in an oxygen concentrator in which an adsorption process starts from an adsorption tower after regeneration (see Patent Document 1).
JP-A-61-187916 (first page)

Similarly, in the case of the heatless dryer apparatus, when the apparatus in operation is stopped by the stop operation by the device manager, the apparatus is normally stopped under the control of the safety stop program.
In an example of the stop control, in order to stop the two adsorption towers in a pressure-equalized state, the stop signal (including a remote switch etc.) is input to detect the time from valve switching to pressure increase (delay). ) To safely stop the device.
In particular, in a relatively large heatless dryer apparatus, intake air control and purge air control are performed by a pneumatic open / close valve driven by compressed air. For this reason, it is necessary to suitably control the pneumatic open / close valve to stop the apparatus. However, when the stop signal is input as described above and controlled by the safety stop program, the apparatus can be stopped normally.

On the other hand, if a stop operation is performed without a stop signal being input due to a disturbance such as a power failure, the pneumatic open / close valve (intake valve, exhaust valve) stops at an abnormal position and cannot be restarted. There is. According to this, it becomes impossible to supply the dehumidified compressed gas continuously.
Specifically, in the case of a restart operation after an abnormal stop such as a power failure, an unexpected sudden change of the intake valve occurs when the power is turned on again, resulting in a rush of compressed air and deformation of the components inside the adsorption tower. Or it may be damaged. When the internal parts are damaged in this way, compressed air leaks and the like, and the normal operation state cannot be restored.
An abnormal stop occurs when an abnormal drop in the supply voltage to the device, a momentary power failure, a power failure for several seconds, electromagnetic noise, or the like occurs. An abnormal stop also occurs due to an artificial cause. When the operation switch of the device manager is erroneously operated, the safety stop (complete stop operation) is not performed, and the same problem occurs. For example, there are frequent switch operations and sudden ON-OFF.

The problem to be solved regarding the compressed gas dehumidification continuous supply method and the compressed gas dehumidifier is that the restart operation may not be possible in some cases when the system stops abnormally, and the dehumidified compressed gas can be continuously supplied. It is to disappear.
Therefore, an object of the present invention is to provide a continuous supply method and a compressed gas dehumidifying device for dehumidifying compressed gas that can be continuously operated even when the apparatus is stopped abnormally and can continuously supply dehumidified compressed gas. It is to provide.

The present invention has the following configuration in order to achieve the above object.
According to one mode of the continuous supply method in the dehumidification of compressed gas according to the present invention, the compressed gas is guided to one of the two adsorption towers filled with the adsorbent, and the moisture of the compressed gas is adsorbed and dehumidified. From the adsorbent whose adsorbing capacity is reduced by introducing a drying process in which the dry gas is discharged and a part of the compressed gas dried by the drying process to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous process A dry gas is obtained by performing a regeneration step for regenerating the adsorbent by desorbing and exhausting moisture in parallel, and performing these drying steps and regeneration steps alternately between the two adsorption towers. In the drying step, the intake valve that is provided for each adsorption tower and is driven to open and close by compressed gas is operated to control the intake, and the device that performs the above steps is turned off abnormally. In the event of occurrence of a malfunction, the supply of compressed gas that opens and closes the two intake valves is stopped, and when the operation of the apparatus is resumed, the operating states of the two intake valves become the same as when the power is turned off. As described above, the compressed gas for driving the intake valve is supplied.

  Further, according to another embodiment of the continuous supply method for dehumidifying compressed gas according to the present invention, the compressed gas is guided to one of the two adsorption towers filled with the adsorbent, and the moisture of the compressed gas is absorbed and dehumidified. As a result, a drying process for discharging a dry gas, and a part of the compressed gas dried by the drying process was led to the other adsorption tower where the moisture of the compressed gas was adsorbed and dehumidified in the previous process, resulting in a decrease in adsorption capacity. Performing a regeneration step of desorbing moisture from the adsorbent and exhausting it to regenerate the adsorbent in parallel, and performing these drying steps and regeneration steps alternately between the two adsorption towers. In the drying step, the intake valve is provided for each adsorption tower and is opened and closed by the compressed gas to control the intake air. When normal disconnection occurs, supply of compressed gas for opening and closing the two intake valves is stopped, and after a predetermined time elapses until the pressure inside the two adsorption towers becomes substantially uniform, The operation is resumed.

  Further, according to one embodiment of the compressed gas dehumidifying device according to the present invention, a first adsorption tower and a second adsorption tower filled with an adsorbent that adsorbs and dehydrates the moisture of the introduced compressed gas, and A first suction passage for guiding compressed gas to the first adsorption tower; a second suction passage for guiding compressed gas to the second adsorption tower; a first discharge passage for discharging dry gas from the first adsorption tower; A second discharge passage for discharging dry gas from the second adsorption tower, a connection path between the adsorption towers communicating the first adsorption tower and the second adsorption tower, and a part dried by the second adsorption tower A first purge exhaust passage for exhausting compressed gas which is guided to the first adsorption tower through the connection path between the adsorption towers and desorbs moisture from the adsorbent to regenerate the adsorbent; and the first adsorption tower Part of the dried product is led to the second adsorption tower via the connection path between the adsorption towers and adsorbed. A second purge exhaust passage for exhausting the compressed gas that has been desorbed from moisture to regenerate the adsorbent, a first intake valve that is driven by the compressed gas to open and close the first suction passage, and A second intake valve that is driven by compressed gas so as to open and close the second intake passage; a first position that controls the first intake valve to open the first intake passage; and the second intake passage is opened. A second position for controlling the second intake valve, and a third position for automatically stopping the output of the compressed gas for opening and closing the first intake valve and the second intake valve when the power is cut off. A pilot valve, and control means for controlling the pilot valve so that the operating state of the first intake valve and the second intake valve is the same as that when the power is turned off when the operation of the apparatus is resumed. Do And wherein the door.

  Moreover, according to the other form of the compressed gas dehumidification apparatus concerning this invention, the 1st adsorption tower and the 2nd adsorption tower which were filled with the adsorption agent which adsorbs and dehumidifies the moisture of the introduce | transduced compressed gas, and A first suction passage for guiding compressed gas to the first adsorption tower; a second suction passage for guiding compressed gas to the second adsorption tower; a first discharge passage for discharging dry gas from the first adsorption tower; A second discharge passage for discharging dry gas from the second adsorption tower, a connection path between the adsorption towers connecting the first adsorption tower and the second adsorption tower, and a part dried by the second adsorption tower. A first purge exhaust passage that exhausts compressed gas that is guided to the first adsorption tower through the connection path between the adsorption towers and desorbs moisture from the adsorbent to regenerate the adsorbent, and the first adsorption. A portion dried in the tower is led to the second adsorption tower through the inter-adsorption tower connection path and absorbed. A second purge exhaust passage that exhausts the compressed gas that has been desorbed from the agent to regenerate the adsorbent, a first intake valve that is driven by the compressed gas to open and close the first suction passage, and A second intake valve driven by compressed gas to open and close the second intake passage, a first position for controlling the first intake valve to open the first intake passage, and the second intake passage. A two-position pilot valve having a second position for controlling the second intake valve to open, and a pilot passage through which compressed gas is output from the pilot valve to open and close the first intake valve and the second intake valve The pilot passage opening / closing means that automatically closes the pilot passage when the power is cut off and the pilot until the predetermined time elapses when the operation of the apparatus is resumed. Characterized by a control means for controlling the opening and closing means of the pilot passage to maintain the closed state of the bets passage.

  Further, according to one aspect of the compressed gas dehumidifying device of the present invention, the pilot passage opening / closing means is an electromagnetic valve and is electrically connected to the control means, and the control means includes a delay circuit as a component. It can be characterized by.

  According to the continuous supply method and the compressed gas dehumidifying device for dehumidifying compressed gas of the present invention, the compressed gas is dehumidified so that continuous re-operation is possible even when the device is abnormally stopped due to abnormal disconnection of the power source or the like. Is advantageous in that it can be continuously supplied.

Hereinafter, an example of the best mode of a dehumidifying device for compressed gas according to the present invention will be described in detail with reference to the accompanying drawings (FIG. 1). FIG. 1 is an air circuit diagram for explaining a compressed gas dehumidifier according to the present invention. In addition, although this form is an apparatus which dehumidifies compressed air and may be described as "air" instead of "gas", this invention is not limited to "air".
10 is a 1st adsorption tower, 20 is a 2nd adsorption tower. Hereinafter, in order to simplify the description, the first adsorption tower 10 may be described as “A tower” and the second adsorption tower 20 may be described as “B tower”. In FIG. 1, [CLM A] is indicated for the A tower and [CLM B] is indicated for the B tower. The first adsorption tower 10 (A tower) and the second adsorption tower 20 (B tower) are filled with an adsorbent that adsorbs and dehumidifies the moisture of the introduced compressed gas.

Reference numeral 11 denotes a first suction passage, which is a passage that guides compressed gas to the A tower. Reference numeral 21 denotes a second suction passage, which is a passage for guiding compressed gas to the B tower.
A first intake valve 12 is an opening / closing means for opening and closing the first intake passage 11. Reference numeral 22 denotes a second intake valve, which is an opening / closing means for opening and closing the second intake passage 21.
The first intake valve 12 and the second intake valve 22 are pneumatically operated valves that are driven by compressed gas (compressed air), and their opening and closing are controlled by the pilot valve 30. The pilot valve 30 is an electrically operated electromagnetic valve, and is controlled by a control device 50 that is electrically connected (wiring is not shown). Therefore, the pilot valve 30 and the control device 50 constitute opening / closing control means for the intake valves 12 and 22.
Reference numeral 31 denotes a compressed air inlet, and reference numeral 32 denotes an intake side filter.

The pilot valve 30 of the present embodiment is an electromagnetic control valve provided with a three-position connection switching means.
When the pilot valve 30 is in the first position, the first intake valve 12 and the second intake valve 22 are controlled so that the first intake passage 11 is opened and the second intake passage 21 is closed.
Specifically, the first pilot passage 38, in which one solenoid (right side in the drawing) of the pilot valve 30 is energized and the connection switching means on one side (right side in the drawing) of the pilot valve 30 is a passage of driving air. And connected to the second pilot passage 39. Then, the compressed air supply source and the first pilot passage 38 communicate with each other via the pilot valve 30, and the compressed air is compressed to the opening drive portion of the first intake valve 12 via the drive air passage 38 a branched from the first pilot passage 38. Air is supplied, and compressed air is supplied to the closing drive portion of the second intake valve 22 through the similarly branched drive air passage 38b. Further, the second pilot passage 39 is opened to the atmosphere via the pilot valve 30. As a result, the first suction passage 11 is opened and the second suction passage 21 is closed, compressed air is introduced into the tower A through the first intake valve 12, and the compressed air dried in the tower A is discharged into the first discharge passage 13. It is discharged as product air through.

Next, when the pilot valve 30 is in the second position, the second intake valve 22 and the first intake valve 12 are controlled to open the second intake passage 21 and close the first intake passage 11.
Specifically, the other solenoid (left side in the drawing) of the pilot valve 30 is energized, and the connection switching means on the other side (left side in the drawing) of the pilot valve 30 is the second pilot passage 39 which is a passage for driving air. And connected to the first pilot passage 38. Then, the compressed air supply source and the second pilot passage 39 communicate with each other via the pilot valve 30, and the compressed air is compressed to the opening drive portion of the second intake valve 22 via the drive air passage 39 b branched from the first pilot passage 39. Air is supplied, and compressed air is supplied to the closing drive portion of the first intake valve 12 through the similarly branched drive air passage 39a. Further, the first pilot passage 38 is opened to the atmosphere via the pilot valve 30. As a result, the second suction passage 21 is opened and the first suction passage 11 is closed, compressed air is introduced into the B tower through the second intake valve 22, and the compressed air dried in the B tower is supplied to the second discharge passage 23. It is discharged as product air through.
When the power supply is cut off, the pilot valve 30 is connected to the first intake valve 12 as shown in FIG. 1 so that the supply of compressed gas for opening and closing the first intake valve 12 and the second intake valve 22 is automatically stopped. The pilot passage 38 and the second pilot passage 39 are both returned to the central position which is the third position. Thus, the pilot valve 30 is a three-position closed center specification electromagnetic control valve.

Further, the control device 50 controls the pilot valve 30 so that the operating states of the first intake valve 12 and the second intake valve 22 are the same as when the power is turned off when the operation of the device is resumed. It is also a control means.
With the above configuration, the intake valves 12 and 22 that are provided for the respective adsorption towers 10 and 20 and are driven to open and close by the compressed gas are operated to control intake air. When the supply of compressed gas for opening and closing the intake valves 12 and 22 is stopped and the operation is resumed, the intake valves 12 and 22 are set so that the operating states of the two intake valves 12 and 22 are the same as when the power is turned off. A device capable of supplying the compressed gas for driving 22 is suitably provided.

Reference numeral 13 denotes a first discharge passage, which is a passage for discharging dry gas from the A tower. Reference numeral 23 denotes a second discharge passage, which is a passage through which dry gas is discharged from the B tower.
14 and 24 are check valves, which are provided in the first discharge passage 13 and the second discharge passage 23, respectively. The check valves 14 and 24 are check valves that suitably discharge the dry gas discharged as the product gas and prevent the backflow.
Reference numeral 35 denotes a discharge passage for product air, which is connected to the first discharge passage 13 and the second discharge passage 23 via check valves 14 and 24. 36 is a filter on the exhaust side, and 37 is an outlet for product air.
With the above configuration, drying is performed in which the compressed gas is guided to one of the two adsorption towers 10 and 20 filled with the adsorbent, and the moisture of the compressed gas is adsorbed and dehumidified to discharge the dry gas. Means are configured.

Reference numeral 33 denotes a connection path between the adsorption towers, which is a passage that connects the A tower and the B tower. The inter-adsorption tower connection path 33 is connected to the side where the discharge passages 13 and 23 of the adsorption towers 10 and 20 are communicated. This is because, instead of the compressed air that has just been sucked into the adsorption towers 10 and 20 and contains moisture, the dried compressed gas is guided from one adsorption tower to the other adsorption tower.
In addition, a purge orifice 34 is provided in the inter-adsorption tower connecting path 33 as means for adjusting the gas flow rate. Thereby, the compressed air of a fixed flow volume passes.

  Reference numeral 15 denotes a first purge exhaust passage, and a part dried in the tower B is led to the tower A via the inter-adsorption tower connection path 33 to desorb moisture from the adsorbent to regenerate the adsorbent. It is a passage for exhausting compressed gas. Reference numeral 25 denotes a second purge exhaust passage, and a part of the air dried by the tower A is guided to the tower B via the inter-adsorption tower connection path 33 to desorb moisture from the adsorbent and regenerate the adsorbent. It is a passage for exhausting compressed gas.

Reference numeral 16 denotes a first exhaust valve, which is a pneumatic on-off valve that is driven by compressed air so as to open and close the first purge exhaust passage 15. Reference numeral 26 denotes a second exhaust valve, which is a pneumatic on-off valve that is driven by compressed air so as to open and close the second purge exhaust passage 25.
Reference numeral 17 denotes a first electromagnetic control valve that controls the opening and closing of the first exhaust valve 16 by switching the compressed air flow path. When the compressed air pressure (compressed air) is introduced (output) into the closing drive air passage 18, the first exhaust valve 16 is closed, and when the compressed air is output to the opening drive air passage 19, the first exhaust valve 16 is opened (see FIG. 2). ). Reference numeral 27 denotes a second electromagnetic control valve that controls the opening and closing of the second exhaust valve 26 by switching the compressed air flow path. When pressurized air is output to the closing drive air passage 28, the second exhaust valve 26 is closed, and when pressurized air is output to the opening drive air passage 29, the second exhaust valve 26 is opened (see FIG. 2).
The electromagnetic control valves 17 and 27 are two-position control valves that control the exhaust valves 16 and 26 to close when the power is turned off. The electromagnetic control valves 17 and 27 are similarly controlled during an abnormal stop such as a power failure. The electromagnetic control valves 17 and 27 are electrically operated electromagnetic valves, and are controlled by a control device 50 that is electrically connected (wiring is not shown). Therefore, the electromagnetic control valves 17 and 27 and the control device 50 constitute opening / closing control means for the exhaust valves (16 and 26).
A silencer 49 is provided to mute the sound generated by the purge air exhausted from the exhaust valves 16 and 26.

  With the above configuration, a part of the compressed gas dried in the drying step is led to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous step, and moisture is desorbed from the adsorbent whose adsorption capacity is reduced. Regeneration means for performing a regeneration step of exhausting and regenerating the adsorbent in parallel with the drying step is configured.

A pressure sensor 40 is connected to the flow path 41 on the compressed air supply source side, and generates a signal when the pressure (air pressure) on the supply source side falls below a preset value.
In response to the signal of the pressure sensor 40, the exhaust valve opening / closing control means including the electromagnetic control valves 17 and 27 and the control device 50 as described above closes both the first exhaust valve 16 and the second exhaust valve 26. To control.
The control device 50 stops the operation of the entire device after both the first exhaust valve 16 and the second exhaust valve 26 are closed by the exhaust valve opening / closing control means. Thus, the control device 50 of this embodiment also functions as an operation control unit and controls the entire device.

The pressure sensor 40 of this embodiment is connected to a flow path 41 that supplies driving air for each control valve (the pilot valve 30, the first electromagnetic control valve 17, and the second electromagnetic control valve 27). Further, in this embodiment, the flow paths 41 a and 41 b connected to the A tower side and the B tower side across the orifice 34 of the inter-adsorption tower connection path 33 merge to form the flow path 41. The flow path 41 is supplied with dry air processed in the tower A or tower B as drive air for each control valve, and is suitable as a part for detecting air pressure. The mounting position of the pressure sensor 40 is not limited to this. For example, the pressure sensor 40 is provided in the passage 61 in the vicinity of the humidity sensor 60 that has substantially the same pressure as the air pressure of the driving air of each control valve on the dry air discharge side. Also good.
In addition, check valves 42 and 42 are arranged in the middle of the flow paths 41a and 41b connected to the A tower side and the B tower side. Reference numeral 45 is a pressure meter, and 43 and 62 are filters.

Next, the operation of the present embodiment will be described in detail with reference to FIG.
First, the operation during normal operation will be described.
In the state shown in FIG. 1, all the solenoids of each control valve (pilot valve 30, first electromagnetic control valve 17, second electromagnetic control valve 27) are not energized, and each control valve is in an OFF state. It has become. That is, the entire apparatus is in an OFF state.
In this state, even when compressed air (driving air) for driving is supplied to the pilot valve 30, the pilot valve 30 is in the central closed position, and either the first intake valve 12 or the second intake valve 22 is located. In contrast, drive air is not supplied.
On the other hand, when the driving air is supplied to the first electromagnetic control valve 17 and the second electromagnetic control valve 27, the driving air is output so that the first exhaust valve 16 and the second exhaust valve 26 are kept closed. To do.

Next, a description will be given of a case where the drive air is supplied to each control valve and energized, and the entire apparatus is operated in a steady state.
One solenoid (right side in the drawing) of the pilot valve 30 is energized, and connection switching means on one side (right side in the drawing) of the pilot valve 30 is connected to the first pilot passage 38 and the second pilot passage 39. Then, the pressure of the compressed air is output through the first pilot passage 38, and the second pilot passage 39 is released to the atmosphere. Thus, the drive air supplied via the pilot valve 30 opens the first intake valve 12 and closes the second intake valve 22. Thereby, the compressed air is introduced into the A tower through the intake valve 12, and the compressed air dried in the A tower is discharged as product air through the first discharge passage 13.
For a predetermined period of time during this period, the solenoid of the second electromagnetic control valve 27 is energized, so that one of the second electromagnetic control valves 27 (the left side in the drawing) is connected to the drive air passages 28 and 29. Connected, the second exhaust valve 26 opens. As a result, a part of the compressed air dried in the tower A is introduced into the tower B through the inter-adsorption tower connection path 33, and the compressed air that has regenerated the adsorbent in the tower B is purged from the second exhaust valve 26. As exhausted.

Then, the other solenoid (left side in the drawing) of the pilot valve 30 is energized, and the other (left side in the drawing) connection switching means of the pilot valve 30 is connected to the first pilot passage 38 and the second pilot passage 39. The Then, the pressure of compressed air is output through the second pilot passage 39, and the first pilot passage 38 is released to the atmosphere. Thus, the drive air supplied through the pilot valve 30 opens the second intake valve 22 and closes the first intake valve 12. Thereby, the compressed air is introduced into the B tower through the intake valve 22, and the compressed air dried in the B tower is discharged as product air through the second discharge passage 23.
For a predetermined period of time during this period, the solenoid of the first electromagnetic control valve 17 is energized, so that one of the first electromagnetic control valves 17 (the left side in the drawing) is connected to the drive air passages 18 and 19. Connected, the first exhaust valve 16 opens. As a result, a part of the compressed air dried in the tower B is introduced into the tower A through the inter-adsorption tower connection path 33, and the compressed air that has regenerated the adsorbent in the tower A is purged from the first exhaust valve 16. As exhausted.
By repeating the above series of steps alternately, the dried compressed air can be continuously supplied.

Next, the case where the apparatus is stopped will be described focusing on the operations of the pilot valve 30 and the exhaust valves 16 and 26.
When the power switch is turned off and a stop signal is issued and the safety program appropriately stops, each control valve (pilot valve 30, first electromagnetic control valve 17, second electromagnetic control valve 27) is in a non-energized state. If there is no pressure change at the inlet 31 and the outlet 37, the air pressure applied to each control valve is maintained.
According to this, when the power switch is turned off, both the electromagnetic control valves 17 and 27 are in a non-energized state and return to the state shown in FIG. That is, the electromagnetic control valves 17 and 27 are controlled to close the exhaust valves 16 and 26. Immediately after the power switch is turned off, the compressed air for driving (driving air) has a sufficient air pressure. Therefore, the exhaust valves 16 and 26 are closed by being controlled by the electromagnetic control valves 17 and 27. In addition, by closing the exhaust valves 16 and 26 in this way, the pressure in the two adsorption towers 10 and 20 is equalized, and then the entire apparatus is stopped.
Therefore, when the operation is resumed, since the pressure in the two adsorption towers 10 and 20 is equalized, a sudden pressure change due to the introduction of compressed air occurs even if the intake valves 12 and 22 are opened and closed. Without damage, damage to the components inside the adsorption towers 10 and 20 can be prevented. Moreover, the air pressure for operating the air circuit can be suitably obtained without leaking from the exhaust valves 16 and 26, and the apparatus can be suitably restarted.

Even when the apparatus is stopped due to an abnormal situation such as an abnormal power-off or a sudden ON-OFF of the power supply, according to the present embodiment, the apparatus can be appropriately stopped and restarted. This will be described below based on the time charts of FIGS.
If the abnormal power supply is cut off during the steady operation, the pilot valve 30 automatically returns to the initial state, which is the third position, by the spring force. This is the state shown in FIG. 1, and drive air is not supplied to either the first intake valve 12 or the second intake valve 22. As shown in FIG. 2, the output of compressed air (pressure) to the first pilot passage (passage 38) and the second pilot passage (passage 39) is turned off. As a result, the open / close state of the first intake valve 12 and the second intake valve 22 is maintained at the time when the power is shut off. In the case after the first power shutdown shown in FIG. 2, the state where the first intake valve 12 is opened and the second intake valve 22 is closed is maintained.
In this way, even when the previous stage is in any situation, the supply of drive air for operating the first intake valve 12 and the second intake valve 22 is stopped when the power is shut off. Accordingly, the first intake valve 12 and the second intake valve 22 are not suddenly opened and closed. Thereby, a sudden pressure change due to the compressed air introduced through the intake valves 12 and 22 does not occur, and it is possible to prevent the internal components of the adsorption towers 10 and 20 from being damaged.

Further, according to the present embodiment, even when the power is restored including the case where the power is automatically turned on again such as a power failure for a short time, the operation can be appropriately resumed.
First, when the power is shut off, the control device 50 that controls the pilot valve 30 stores the control state of the pilot valve 30 at that time.
As shown in FIG. 2, after the power is turned on again, the control device 50 performs a restoring operation based on the storage of the control status of the pilot valve 30. Taking the case of the first power shutdown shown in FIG. 2 as an example, the power supply is shut off while the pressure output to the pilot passage 38 is ON. Action is taken. Therefore, the pressure output to the pilot passage 38 is returned to the ON state, and the first intake valve 12 is controlled to be maintained for a certain period of time.
This restoration operation is programmed so as to be delayed by a predetermined time from the time when the power is turned on again through a delay timer. Thereby, when the operation is restarted after the power is turned on again, the restoration operation is surely performed, so that the operating state of the first intake valve 12 and the second intake valve 22 is the same as the state when the power is turned off. The pilot valve 30 can be controlled. If such a delay means is not used, there may be a case where the restoration operation cannot be performed because the pilot valve 30 operates first while the memory of the control status of the pilot valve 30 is being read.

As described above, when the power is turned on again, the operation is resumed in the state where the power is returned to the original state. Therefore, a sudden pressure change caused by the compressed air introduced through the intake valves 12 and 22 does not occur. It does not occur, and it is possible to prevent the internal components of the adsorption towers 10 and 20 from being damaged. In particular, it is possible to cope with a case where the power is turned on again and the operation is restarted before the two adsorption towers 10 and 20 are equalized, such as a power failure for a short time.
Therefore, according to this embodiment, even if there is an abnormal stop, the compressed gas dehumidifying device can be preferably continuously operated.

Further, even when the apparatus is abnormally stopped due to an abnormal situation in which the pressure (air pressure) on the compressed air supply source side is reduced regardless of the stop signal, according to the present embodiment, the apparatus can be appropriately stopped as follows. .
When the air pressure decreases, the pressure sensor 40 detects it and generates an analog signal.
Upon receiving the signal, the control device 50 electrically controls the solenoids of both the electromagnetic control valves 17 and 27 so that they are not energized (OFF state shown in FIG. 1). As a result, while the air pressure is sufficient to control the exhaust valves 16 and 26, the exhaust valves 16 and 26 are closed by being controlled by the electromagnetic control valves 17 and 27. By closing the exhaust valves 16 and 26 in this way, the pressure in the two adsorption towers 10 and 20 is equalized. Thereafter, the entire apparatus is stopped by the operation control means comprising the control device 50.
Therefore, when the operation is resumed, the air pressure for operating the air circuit can be suitably obtained without causing the compressed air to leak from the exhaust valves 16 and 26, as in the case of the normal stop. The apparatus can be suitably restarted.
For this reason, even when the apparatus is abnormally stopped, it is possible to continue the operation again, and there is an advantageous effect that the dehumidified compressed gas can be continuously supplied.
Note that when the compressor stops due to an abnormality on the compressed air supply source (compressor) side, if the power of the compressor is separate and the electricity stops for some reason, including artificial causes, There are cases where the usage amount is higher than expected and the air pressure drops, or the piping is damaged.

Next, another example of the best mode of the compressed gas dehumidifying apparatus according to the present invention will be described in detail with reference to the accompanying drawings (FIG. 3). FIG. 3 is an air circuit diagram for explaining a compressed gas dehumidifier according to the present invention. In addition, although this form is an apparatus which dehumidifies compressed air and may be described as "air" instead of "gas", this invention is not limited to "air".
The same components as those of the compressed gas dehumidifier described above are denoted by the same reference numerals, and description thereof is omitted.
Reference numeral 70 denotes a two-position pilot valve, which is an electromagnetic valve that is electrically connected to the control device 50 and controlled. This two-position pilot valve controls the first intake valve 12 to open the first intake passage 11 when in the first position, and opens the second intake passage 21 when in the second position. The second intake valve 22 is controlled.

Reference numeral 71 denotes a first on-off valve, which is provided to open and close the first pilot passage 38. A second opening / closing valve 72 is provided to open and close the second pilot passage 39.
These on-off valves 71 and 72 open and close pilot passages 38 and 39 for supplying compressed gas for opening and closing the first intake valve 12 and the second intake valve 22 from the pilot valve 70 at two positions, and the power supply is cut off. In this case, the pilot passages 38 and 39 are automatically opened and closed.
The pilot passage opening / closing means (open / close valves 71, 72) are electromagnetic valves and are electrically connected to the control device 50, which is a control means. The solenoids of the on-off valves 71 and 72 are stopped when the power is cut off, and automatically return to the initial closed state by a spring.
The exhaust valves 16 and 26 are also closed by being controlled by the electromagnetic control valves 17 and 27 when the power is shut off.
The control device 50 includes a delay circuit as a component, and controls the on-off valves 71 and 72 so that the pilot passages 38 and 39 are kept closed until a predetermined time elapses when restarting operation. It has become a means.

As a result, the supply of drive air for operating the first intake valve 12 and the second intake valve 22 is stopped when the power supply is cut off, similarly to the function of the pilot valve 30 described above, by the on-off valves 71 and 72. Accordingly, even when the power supply is abnormally disconnected, the first intake valve 12 and the second intake valve 22 are not suddenly opened and closed. Therefore, a sudden pressure change due to the compressed air introduced through the intake valves 12 and 22 does not occur, and damage to the components inside the adsorption towers 10 and 20 can be prevented.
It is programmed so that a predetermined time is required by the control means (control device 50) including delay means such as a delay circuit until the on-off valves 71 and 72 are opened after the power is shut off. The control device 50 also controls the exhaust valves 16 and 26 so that they do not open until a predetermined time has elapsed. Specifically, the exhaust valves 16 and 26 are kept closed by controlling the electromagnetic control valves 17 and 27 not to be energized by the delay means.
In this way, by restarting the operation after a predetermined time has elapsed after the power is shut off, the pressures inside the two adsorption towers 10 and 20 are substantially uniformized. For this reason, even if there is an opening / closing operation of the intake valves 12 and 22 thereafter, a sudden pressure change due to the introduction of compressed air does not occur, and damage to the components inside the adsorption towers 10 and 20 can be prevented.
Therefore, according to this embodiment, even if there is an abnormal stop, the compressed gas dehumidifying device can be preferably continuously operated.

  As described above, the present invention has been variously described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course you get.

It is a circuit diagram showing one embodiment of a dehumidifying device for compressed gas according to the present invention. It is a time chart explaining operation | movement of the dehumidification apparatus of the compressed gas of FIG. It is a circuit diagram which shows other embodiment of the dehumidification apparatus of the compressed gas concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st adsorption tower 11 1st suction passage 12 1st intake valve 13 1st discharge passage 15 1st purge exhaust passage 16 1st exhaust valve 17 1st electromagnetic control valve 20 2nd adsorption tower 21 2nd suction passage 22 2nd 2 Intake valve 23 Second exhaust passage 25 Second purge exhaust passage 26 Second exhaust valve 27 Second electromagnetic control valve 30 Pilot valve 33 Connection between adsorption towers 38 First pilot passage 39 Second pilot passage 50 Control device 70 2 Pilot valve in position 71 First on-off valve 72 Second on-off valve

Claims (2)

A drying step of discharging the dry gas by introducing the compressed gas to one of the two adsorption towers filled with the adsorbent and the moisture of the compressed gas being adsorbed and dehumidified;
A part of the compressed gas dried in the drying step is led to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous step, and the moisture is desorbed and exhausted from the adsorbent whose adsorption capacity is reduced. In parallel with the regeneration process to regenerate the adsorbent,
By continuously performing these drying steps and regeneration steps alternately between the two adsorption towers, the dry gas is continuously discharged,
In the drying step, the intake valve that is provided for each adsorption tower and is driven to open and close by compressed gas is operated to control intake air,
When an abnormal disconnection of the power supply occurs for the apparatus that performs the above steps, supply of compressed gas that opens and closes the two intake valves is stopped,
Compressed gas dehumidification, wherein when the operation of the apparatus is resumed, compressed gas for driving the intake valves is supplied so that the operating states of the two intake valves are the same as when the power is turned off. Continuous supply method. A first adsorption tower and a second adsorption tower filled with an adsorbent that adsorbs and dehydrates the moisture of the introduced compressed gas; and
A first suction passage for guiding compressed gas to the first adsorption tower, and a second suction passage for guiding compressed gas to the second adsorption tower;
A first discharge passage for discharging dry gas from the first adsorption tower, and a second discharge passage for discharging dry gas from the second adsorption tower;
A connection path between the adsorption towers communicating the first adsorption tower and the second adsorption tower;
A part dried in the second adsorption tower is led to the first adsorption tower via the inter-adsorption tower connecting path, and moisture is desorbed from the adsorbent to exhaust the compressed gas regenerated by the adsorbent. The first purge exhaust passage and a part dried in the first adsorption tower are led to the second adsorption tower via the inter-adsorption tower connection path, and moisture is desorbed from the adsorbent to remove the adsorbent. A second purge exhaust passage for exhausting the regenerated compressed gas;
A first intake valve driven by compressed gas to open and close the first intake passage; and a second intake valve driven by compressed gas to open and close the second intake passage;
A first position for controlling the first intake valve to open the first intake passage, a second position for controlling the second intake valve to open the second intake passage, and when the power is cut off Is a pilot valve having a third position that automatically stops the output of compressed gas that opens and closes the first intake valve and the second intake valve;
And a control means for controlling the pilot valve so that the operating states of the first intake valve and the second intake valve are the same as when the power is turned off when the operation of the apparatus is resumed. A dehumidifier for compressed gas.

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