JPH0655029A - Compressed air dryer - Google Patents

Abstract

PURPOSE:To keep the flow rate of air flowing in a pressure reducing restriction mechanism on drying agent regeneration almost constant irrespective of main pressure. CONSTITUTION:A communicating hole 52 is formed for making a drying chamber 11 and an outlet port 27 communicate with each other in an upper cover 11c of the drying chamber 11. A movable restriction member 53 is arranged above the communicating hole 52 and energized upwards by a spring 56. When a drying agent 21 is dried, an exhaust valve 92 is opened to release compressed air in the drying chamber 11 in the air, causing pressure in the drying chamber 11 to be lowered. Consequently, compressed air backflows into the drying chamber 11 through the communicating hole 52 from the outlet port 27 side by the difference in pressure between the outlet port 27 side and the drying chamber 11 side, and simultaneously, the movable restriction member 53 is moved downwards against the spring 56. At this time, the movable restriction member 53 is moved so that the passage resistance of air flowing through the communicating hole 52 may be made large with the increase in the pressure difference to keep the rate of air flowing into the drying chamber 11 almost constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressed air drying apparatus having an improved decompression throttle for reversing compressed air from the outlet port side into the drying chamber when regenerating a desiccant having adsorbed water.

[0002]

2. Description of the Related Art Conventionally, for example, a compressed air drying device disclosed in Japanese Patent Laid-Open No. 3-30813 and a compressed air drying device used for an air suspension for an automobile are
A desiccant for adsorbing moisture in the compressed air introduced into the drying chamber is built in, and the compressed air dried in the drying chamber is sent from the outlet port to a predetermined accumulator tank or the like. In this product, in order to regenerate the desiccant that has absorbed water,
A decompression throttle (orifice) is provided between the outlet port and the drying chamber, and after the drying operation is completed, the exhaust valve is opened to discharge the compressed air in the drying chamber into the atmosphere, so that the dry compressed air in the accumulator tank is removed. The pressure is reduced from the outlet port side through the pressure reducing throttle, and the drier air is made to flow back into the drying chamber, and the dry air removes water from the desiccant and discharges it into the atmosphere.

[0003]

However, in the above-mentioned conventional structure, the pressure reducing throttle is an orifice having a fixed opening area, and therefore the pressure of the accumulator tank communicating with the outlet port (hereinafter referred to as "source pressure"). Is high, the flow rate of the air flowing through the decompression throttle increases, and the flow rate of the air flow through the desiccant in the drying chamber is high. The flow velocity of the air flow through the agent becomes slow. For this reason, the regeneration efficiency of the desiccant, which depends on the flow velocity of the air flow, may fluctuate depending on the level of the source pressure, and the desiccant may not be sufficiently regenerated. (Time) also fluctuates depending on the level of the source pressure, especially
There is also a drawback that the regeneration time must be lengthened when the source pressure is low. However, if the opening area of the decompression throttle is increased in order to shorten the regeneration time, the flow velocity of the air flow passing through the desiccant becomes too fast when the original pressure is high, and the desiccant is caused by the air flow. (Silica gel etc.) may be broken.

The present invention has been made in consideration of such circumstances, and an object thereof is to dry the desiccant by making the flow rate of the air flowing through the depressurization squeezing mechanism almost constant, regardless of whether the original pressure is high or low. It is an object of the present invention to provide a compressed air drying device capable of improving the regeneration efficiency and shortening the regeneration time while preventing pulverization of the agent.

[0005]

In order to achieve the above object, the compressed air drying apparatus of the present invention has an inlet port for introducing compressed air to be dried and a moisture content in the compressed air introduced from the inlet port. A drying chamber containing a desiccant to be adsorbed, an outlet port for sending dry compressed air from the drying chamber to a predetermined location, and a check valve that allows only the flow of compressed air from the drying chamber to the outlet port, A decompression throttle mechanism provided between the drying chamber and the outlet port, and an exhaust valve for communicating and shutting off the drying chamber with the atmosphere, wherein the decompression throttle mechanism is provided with the drying chamber. It is possible to change the flow path resistance of the air flow passing through the communicating hole by receiving the pressure of the outlet port and the pressure of the drying chamber from both sides and moving by the pressure difference between the communicating hole that communicates with the outlet port. It is composed of a diaphragm member.

[0006]

When the desiccant in the drying chamber is regenerated, after the supply of the compressed air to the drying chamber (drying operation) is finished, the exhaust valve is opened to communicate the drying chamber with the atmosphere, and the compressed air in the drying chamber is discharged. It is discharged into the atmosphere to reduce the pressure in the drying chamber. As the pressure in the drying chamber decreases, the pressure (source pressure) on the outlet port side becomes higher than the pressure in the drying chamber, and the pressure difference causes compressed air to dry from the outlet port side through the communication hole of the decompression throttle mechanism. While flowing back into the room, the movable throttle member of the decompression throttle mechanism moves due to the pressure difference between the outlet port side and the drying chamber side. At this time, the movable throttle member moves so as to increase the flow path resistance of the air flow passing through the communication hole as the pressure difference increases, thereby making the air flow rate from the outlet port side into the drying chamber substantially constant.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. An inlet port 13 for introducing compressed air from an air compressor (not shown) is provided below the cylindrical body 12 forming the drying chamber 11. The inlet port 13 is provided with a check valve 15 biased by a spring 14 in order to prevent backflow of compressed air. An inlet passage 16 is formed in communication with the check valve 15, and a cylindrical water separation chamber 17 is formed in communication with the inlet passage 16.
Are formed. As shown in FIG. 4, the positional relationship between the water separation chamber 17 and the inlet passage 16 is such that the inlet passage 16 is formed at a position eccentric with respect to the cylindrical water separation chamber 17, and compressed air is supplied from the inlet passage 16 to the compressed air. Are blown along the inner peripheral surface of the water separation chamber 17. Thereby, the compressed air is swirled at high speed along the inner peripheral surface of the water separation chamber 17, and the condensed water in the compressed air is separated by the cyclone effect (centrifugal separation effect).

As shown in FIG. 1, in the water separation chamber 17, there is provided a funnel-shaped introduction pipe 18 for introducing compressed air from which condensed water has been separated into the drying chamber 11. This introduction pipe 1
Reference numeral 8 is fixed to the upper partition wall of the water separation chamber 17 in a state in which the tapered expansion portion 18a faces downward. A filter 19 for removing foreign matters in the compressed air is provided above the introduction pipe 18, and the compressed air flows from the passage 20 into the lower space 11b in the drying chamber 11 through the filter 19.

In the drying chamber 11, a desiccant 21 such as silica gel, activated alumina or zeolite which adsorbs water in compressed air is stored. The desiccant 21 is held so as to be sandwiched between the filters 22 and 23 and the perforated plates 24 and 25 from the upper and lower sides, and spaces 11a and 11b are secured in the upper and lower portions of the drying chamber 11. A spring 26 that biases the upper porous plate 24 downward is housed in the upper space 11a.

An outlet port 27 for sending compressed air dried in the drying chamber 11 to, for example, a tire (not shown) is formed in the upper partition wall of the drying chamber 11. The outlet port 27 and the upper space 11a of the drying chamber 11 are
The filter 28 communicates with a rubber check valve 29. This check valve 29 is used in the drying chamber 11
Is pushed up by the pressure to open the outflow hole 30, and the compressed air in the upper space 11a of the drying chamber 11 is filtered by the filter 28 →
Outflow hole 30 (check valve 29) → outlet port 27 is used to flow out.

On the other hand, as shown in FIG. 2, a valve chamber 33 having a drain port 32 at the bottom is provided adjacent to the water separation chamber 17. The valve chamber 33 and the water separation chamber 17 are communicated with each other by a drainage passage 34, and the condensed water accumulated in the water separation chamber 17 flows into the valve chamber 33 through the drainage passage 34. In this valve chamber 33, the poppet type drain valve 3
5 is accommodated in a vertically movable manner, and the drain valve 35 divides the valve chamber 33 into a first pressure chamber 36 and a second pressure chamber 37. In this case, the pressure of the water separation chamber 17 acts on the first pressure chamber 36 through the drainage passage 34, and the pressure of the drying chamber 11 acts on the second pressure chamber 37 through the exhaust throttle 38 and the filter 39. Is configured.

Further, in the second pressure chamber 37, the drain valve 3
A spring 40 for urging the drainage valve 5 is housed, and the urging force of the spring 40 causes the drain valve 35 to move the drainage port 3
2 is kept closed. still,
A seal member 41 is fixedly attached to the lower peripheral edge of the drain valve 35 so that the seal member 41 and the seat portion of the drain valve port 32 come into close contact with each other.

Further, as shown in FIG. 3, an exhaust valve 42 for connecting / disconnecting the second pressure chamber 37 and thus the drying chamber 11 to the atmosphere is provided on the side of the valve chamber 33. The exhaust valve 42 is provided with an upstream chamber 44 that communicates with the second pressure chamber 37 through the passage 43 and a downstream chamber 46 that communicates with the atmosphere through the passage 45. The exhaust valve 42 is an electromagnetic valve, and the plunger 47 has a valve body 4 at the tip thereof.
8 are provided. In this case, the magnet coil 49
In the state in which the valve 47 is not energized, the plunger 47 is projected by the spring 50 so that the valve body 48 moves the upstream chamber 44 and the downstream chamber 46.
It is maintained in a state in which the gap between and is cut off. On the other hand, when the magnet coil 49 is energized, the plunger 47 is attracted against the spring 50, and the valve body 48 brings the upstream chamber 44 and the downstream chamber 46 into communication with each other.

On the other hand, as shown in FIG. 1, a decompression throttle mechanism 51 is provided in parallel with the outflow hole 30 of the check valve 29 so that the compressed air on the tire side (source pressure side) is generated when the desiccant 21 described later is regenerated. The pressure reducing diaphragm mechanism 51 gradually flows into the drying chamber 11. The configuration of the pressure reducing diaphragm mechanism 51 will be described below.

That is, the upper cover 11c of the drying chamber 11 is formed with a communication hole 52 having a circular cross section for communicating the drying chamber 11 and the outlet port 27, and a large diameter hole 54 formed in the upper part of the communication hole 52. The movable diaphragm member 53 is housed therein so as to be vertically movable. An air passage 55 penetrating in the vertical direction is formed in the movable throttle member 53, and further, in the center of the lower surface of the movable throttle member 53, a cylindrical pressure reducing valve head 53a having a diameter smaller than that of the communication hole 52 is directed downward. When the pressure reducing valve head 53a is formed and moves in and out of the communication hole 52, the flow resistance of the air flow passing through the cylindrical flow path formed in the communication hole 52 is changed. The movable diaphragm member 53 includes a spring 5 housed in a lower portion of the large diameter hole 54.
6, the movable diaphragm member 53 is moved to a position where the biasing force of the spring 56 and the pressure difference acting on the movable diaphragm member 53 are balanced. The movable diaphragm member 53 is prevented from pulling out upward by a stop ring 57 mounted on the upper portion of the large diameter hole 54.

Next, the operation of the above configuration will be described.

(1) Operation during compressed air drying operation During this compressed air drying operation, the magnet coil 49 of the exhaust valve 42 is not energized and the exhaust valve 42 is closed. In this state, the valve body 48 is held in the closed position by the spring 50 in the exhaust valve 42, and the upstream chamber 44 and the downstream chamber 46 are shut off from each other. As a result, the second pressure chamber 37 is shut off from the atmosphere, and the pressure of the drying chamber 11 acts on the second pressure chamber 37 through the exhaust throttle 38 and the filter 39.

On the other hand, in the first pressure chamber 36, the drying chamber 11
Since the pressure in the water separation chamber 17 that is substantially the same as the pressure in # 1 acts through the drainage passage 34, the pressure in the first pressure chamber 36 and the pressure in the second pressure chamber 37 are approximately the same, and there is no pressure difference between the two. rare. In this state, the drainage valve 35 is kept closed by the biasing force of the spring 40.

During this compressed air drying operation, the compressed air introduced from the air compressor (not shown) into the inlet port 13 resists the check valve 15 against the spring 14 and is shown in FIG.
To the left to open and flow into the water separation chamber 17 through the inlet passage 16. The inflowing compressed air swirls at high speed along the inner peripheral surface of the water separation chamber 17, and the condensed water in the compressed air is separated by the cyclone effect (centrifugal separation action), and is collected at the bottom of the water separation chamber 17. The condensed water also flows into the first pressure chamber 36 through the drainage passage 34 and accumulates therein.

On the other hand, the compressed air from which the condensed water is separated in the water separation chamber 17 is introduced from the introduction pipe 18 to the filter 19 and the passage 20.
To flow into the lower space 11b of the drying chamber 11 and through the holes of the perforated plate 25 and the filter 23 to flow upward in the desiccant 21. In this process, the moisture in the compressed air is adsorbed by the desiccant 21, becomes dry compressed air, passes through the holes of the filter 22 and the perforated plate 24, and reaches the upper space 11a of the drying chamber 11. The dry compressed air passes through the filter 28, pushes up the check valve 29 from the outflow hole 30 and reaches the outlet port 27 (in parallel with this, a part of the dry compressed air passes through the pressure reducing throttle mechanism 51 and exit port 27. And reaches a predetermined tire (not shown) through the outlet port 27.

(2) During drainage (when the compressed air drying operation is completed)
Operation of When the tire to which the dry compressed air is supplied from the outlet port 27 is accumulated to a predetermined pressure, the air compressor that sends the compressed air to the inlet port 13 is stopped, and the drying operation is completed. Even after this, the pressure in the drying chamber 11 and the pressure in the water separation chamber 17 are kept high by the check valve 15. Therefore, the pressure in the first pressure chamber 36 and the pressure in the second pressure chamber 37 are almost the same, and there is not much pressure difference between the two.

Thereafter, when draining, the magnet coil 49 of the exhaust valve 42 is energized to open the exhaust valve 42. This causes the plunger 47 of the exhaust valve 42 to move to the spring 5
The valve body 48 is sucked against 0, moved to the open position, and the upstream chamber 44 and the downstream chamber 46 are in communication with each other.
As a result, the second pressure chamber 37 is changed from the passage 43 to the upstream chamber 44.
→ The downstream chamber 46 → The passage 45 communicates with the atmosphere,
The compressed air in the second pressure chamber 37 flows out into the atmosphere, and the pressure in the second pressure chamber 37 instantly drops to atmospheric pressure.

On the other hand, in order to reduce the pressure in the first pressure chamber 36, the compressed air in the first pressure chamber 36 is converted into the first pressure chamber 36 → the water separation chamber 17 → the drying chamber 11 → the exhaust throttle 38. → second
The pressure chamber 37 → the exhaust valve 42 → the exhaust air must be discharged through the path, and the volume of the drying chamber is relatively large.
The discharge of the compressed air from the pressure chamber 36 is throttled so that the pressure in the first pressure chamber 36 does not immediately drop but is maintained in a high pressure state for a while. Therefore, for a while after the exhaust valve 42 is opened,
A large pressure difference is generated between the first pressure chamber 36 and the second pressure chamber 37, and this pressure difference moves the drain valve 35 upward against the spring 40 to open the drain port 32. The drainage port 32 communicates with the first pressure chamber 36 and the water separation chamber 17. As a result, the water accumulated in the water separation chamber 17 and the first pressure chamber 36 is put on the flow of the compressed air which is blown out vigorously from the drain port 32 and is quickly discharged.

With this drainage, the compressed air in the first pressure chamber 36 is also discharged from the drainage port 32, so that the pressure in the first pressure chamber 36 is rapidly reduced and the pressure in the second pressure chamber 37 is reduced. As the pressure approaches, the urging force of the spring 40 eventually overcomes the pressure difference between the first pressure chamber 36 and the second pressure chamber 37. At this point, the drain valve 35 is moved downward by the urging force of the spring 40, and the drain port 32
To close. As a result, the first pressure chamber 36 is shut off from the atmosphere.

After the drainage is completed, the exhaust valve 42 is switched to the closed state again, and the second pressure chamber 37 is shut off from the atmosphere. As a result, the state where the drying operation of the compressed air can be started again is restored.

(3) Operation when regenerating the desiccant 21 When regenerating the desiccant 21, the exhaust valve 42 is opened as in the case of drainage. As a result, the second pressure chamber 37 communicates with the atmosphere, the compressed air in the second pressure chamber 37 flows into the atmosphere, and the pressure of the second pressure chamber 37 instantly drops to atmospheric pressure. Therefore, a large pressure difference is generated between the first pressure chamber 36 and the second pressure chamber 37, and the pressure difference causes the drain valve 35 to move upward against the spring 40 to open the drain port 32. To do. As a result, the compressed air in the drying chamber 11 is discharged through the drying chamber 11 → the water separation chamber 17 → the first pressure chamber 36 → the drain port 32 → the air path, and at the same time, the drying chamber 11 → the exhaust throttle 38 → the The pressure in the drying chamber 11 is rapidly reduced by exhausting the gas from the second pressure chamber 37 to the exhaust valve 42 to the atmosphere.

Due to the pressure drop in the drying chamber 11, the pressure (source pressure) on the tire side (exit port 27 side) becomes higher than the pressure in the drying chamber 11, and a small flow rate of compressed air from the tire side due to the pressure difference. As will be described later, it flows back into the drying chamber 11 through the pressure reducing diaphragm mechanism 51. Since this compressed air has a low pressure in the drying chamber 11, the decompression throttle mechanism 51
The volume is expanded while being decompressed by, and the dry air having a humidity lower than that in the high pressure state is released to remove the adsorbed moisture from the desiccant 21 and regenerate the desiccant 21.

At the beginning of opening the exhaust valve 42, as described above,
The compressed air in the drying chamber 11 is the drying chamber 11 → the water separation chamber 17
→ The first pressure chamber 36 → the drain port 32 → is also discharged through the path of the atmosphere, but the pressure of the first pressure chamber 36 is rapidly reduced by the discharge of this compressed air, and eventually the urging force of the spring 40 becomes the first. Since the pressure difference between the first pressure chamber 36 and the second pressure chamber 37 is overcome, at that time, the drain valve 35
Moves downward to close the drain port 32 and shut off the first pressure chamber 36 from the atmosphere. After this, the air from which the desiccant 21 has deprived of water is discharged through the path of the drying chamber 11 → the exhaust throttle 38 → the second pressure chamber 37 → the exhaust valve 42 → the atmosphere.

When the desiccant 21 is regenerated, the movable throttle member 53 of the decompression throttle mechanism 51 receives the pressure (source pressure) on the tire side (outlet port 27 side) from above and the drying chamber 11 from below through the communication hole 52. The pressure will be received by the pressure reducing valve head 53a. As mentioned above, the drying room 1
Since the pressure of No. 1 is lowered, the original pressure becomes higher than the pressure of the drying chamber 11, and the movable throttle member 5 is caused by the pressure difference between the two.
3 receives a downward force and is pushed down against the biasing force of the spring 56. Thereby, the movable diaphragm member 53
Moves to a position where the pressure difference and the urging force of the spring 56 are balanced and stays there.

During the regeneration, the pressure in the drying chamber 11 is almost constant. Therefore, if the original pressure becomes higher, the pressure difference acting on the movable throttle member 53 becomes larger, and the moving amount of the movable throttle member 53 downward. Becomes large, the pressure reducing valve head 53a of the movable throttle member 53 is inserted into the communication hole 52 to form a cylindrical flow path, and the flow path cross-sectional area of the air flow passing through the cylindrical flow path in the communication hole 52 is small. Therefore, the flow path resistance increases. Conversely,
When the original pressure decreases, the amount of downward movement of the movable throttle member 53 decreases, the flow passage cross-sectional area of the air flow passing through the communication hole 52 increases, and the flow passage resistance decreases. As a result, the flow path resistance of the decompression throttle mechanism 51 is automatically adjusted according to the level of the original pressure, and the air flow rate from the outlet port 27 side into the drying chamber 11 is made constant.

Here, the pressure reducing valve head 5 of the movable throttle member 53.
The outer diameter of 3a is d, the inner diameter of the communication hole 52 is D, the moving amount of the movable diaphragm member 53 is x, the original pressure is P1, and the pressure of the drying chamber 11 is P.
2, the air flow rate Q passing through the decompression throttle mechanism 51
Have a relationship represented by the following expression (1).

[0032]

[Equation 1]

As is apparent from the equation (2), the air flow rate Q passing through the pressure reducing throttle mechanism 51 is determined by the outer diameter d of the pressure reducing valve head 53a and the inner diameter D of the communication hole 52, and the original pressure P1
It can be seen that the air flow rate Q does not change even when changes, and becomes constant.

According to the present embodiment described above, the pressure-reducing throttle mechanism 51 has a communication hole 52 for connecting the drying chamber 11 and the outlet port 27, and a movable throttle which moves by the pressure difference between the original pressure and the drying chamber 11. Since the movable diaphragm member 53 is configured to change the flow path resistance of the air flow passing through the communication hole 52 by the movement of the member 53, the decompression diaphragm mechanism 51 of the decompression diaphragm mechanism 51 is regenerated according to the original pressure when the desiccant 21 is regenerated. The flow path resistance can be automatically adjusted, and the air flow rate from the outlet port 27 side into the drying chamber 11 can be made constant. This allows
The flow velocity of the air flow in the drying chamber 11 during regeneration can be always kept at an optimum flow velocity regardless of the level of the original pressure, and the regeneration efficiency of the desiccant 21 can be improved.

Moreover, even if the original pressure is low, the decompression throttle mechanism 51 keeps the air flow rate into the drying chamber 11 at an optimum value, so that the time required for regenerating the desiccant 21 (regeneration time).
Can be shortened compared to the conventional one. Similarly, even when the original pressure is high, the decompression throttle mechanism 51 keeps the air flow rate into the drying chamber 11 at an optimum value, so that the flow velocity of the air flow in the drying chamber 11 does not become excessive, and The desiccant 21 can be prevented from crushing.

The decompression throttle mechanism 51 of the above embodiment is constructed such that the pressure reducing valve head 53a of the movable throttle member 53 is inserted into the communication hole 52 due to the pressure difference to form a cylindrical flow path. The present invention is not limited to this configuration. For example, the pressure reducing valve head portion of the movable throttle member is formed in a tapered shape, and the tapered pressure reducing valve head portion and the communication hole 52 form an orifice. The flow passage cross-sectional area of this orifice may be changed. In this case, when the source pressure changes, the air flow rate changes a little, but compared to the conventional fixed decompression throttle, the change in the air flow rate is small, and the same effect as that of the above embodiment can be expected.

Although a poppet type valve is used as the drain valve 35 in the above embodiment, a diaphragm type drain valve may be used as long as it is a valve that opens and closes due to the pressure difference of compressed air. good.

In addition, the present invention is not limited to the above-mentioned embodiment, for example, the configuration of the check valves 15 and 29 may be changed, and the target for supplying the dry compressed air from the outlet port 27 is not limited to the tire. Needless to say, various modifications may be made without departing from the scope of the invention, such as a pneumatic cylinder or a pressure accumulating tank.

[0039]

As is apparent from the above description, according to the present invention, the decompression throttle mechanism is moved by the communication hole that connects the drying chamber and the outlet port, and the pressure difference between the original pressure and the drying chamber. It is composed of a movable throttle member, and the flow resistance of the air flow passing through the communication hole is changed by the movement of the movable throttle member. The air flow rate and flow velocity into the room can always be kept at optimum values, and the desiccant regeneration efficiency can be improved. Moreover, even when the original pressure is low, the time required for regenerating the desiccant (regeneration time) can be shortened as compared with the conventional one. On the other hand, even when the original pressure is high, the flow velocity of the air flow in the drying chamber does not become excessive, It is possible to prevent the desiccant from being crushed by the air flow.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, which is taken along the line II of FIG.
Cross section shown along the line

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a bottom view showing a bottom surface of the compressed air drying device partially broken away.

FIG. 5 is a diagram showing a pneumatic circuit of a compressed air drying device.

[Explanation of symbols]

11 is a drying chamber, 13 is an inlet port, 15 is a check valve, 17 is a water separating chamber, 21 is a desiccant, 27 is an outlet port, 29 is a check valve, 32 is a drain port, 33 is a valve chamber, 34 is a drain passage. , 35 is a drain valve, 36 is a first pressure chamber, 37 is a second pressure chamber, 38 is an exhaust throttle, 40 is a spring, 42 is an exhaust valve, 48 is a valve element, 51 is a pressure reducing throttle mechanism, and 52 is communication. A hole, 53 is a movable throttle member, 53a is a pressure reducing valve head, and 56 is a spring.

Claims (1)

[Claims] 1. An inlet port for introducing compressed air to be dried, a drying chamber containing a desiccant for adsorbing moisture in the compressed air introduced from the inlet port, and a predetermined location for the compressed compressed air from the drying chamber. An outlet port for sending the compressed air from the drying chamber to the outlet port, a pressure reducing throttle mechanism provided between the drying chamber and the outlet port, In a compressed air drying device including an exhaust valve for communicating and shutting off a chamber with the atmosphere, the decompression throttle mechanism includes a communication hole for communicating the drying chamber and the outlet port, a pressure of the outlet port, and And a movable throttle member that receives the pressure of the drying chamber from both sides and moves according to the pressure difference to change the flow path resistance of the air flow passing through the communication hole. Drying apparatus.