JPH0655030A - Compressed air dryer - Google Patents

Abstract

PURPOSE:To prevent the operation failure of a drain valve and to improve the reliability of automatic drain by opening the drain valve on draining by the pressure difference of compressed air. CONSTITUTION:Compressed air from an air compressor is introduced into a water separation chamber 17 to separate condensed water in the compressed air by the cyclone effect, then moisture is removed in a drying chamber 11 to let the air flow out from an outlet port. A valve chamber 33 adjacent to the water separation chamber 17 is divided into a 1st pressure chamber 36 and a 2nd pressure chamber 37 by a drain valve 38 and the 1st pressure chamber 36 communicates with the water separation chamber 17 and the 2nd pressure chamber 37 communicates with the drying chamber 11 through an exhaust restriction 38. On draining, a solenoid valve communicating with the 2nd pressure chamber 37 is opened to rapidly lower the pressure of the 2nd pressure chamber to the atmospheric one. The drain valve 35 is moved by the pressure difference between the 1st pressure chamber 36 and 2nd pressure chamber 37 to open a drain port 32 in the bottom part of the valve chamber 33. Thus, an evil influence due to rust or freezing is removed by using not a solenoid valve but a non-magnetic substance.

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 device having an improved structure for discharging water separated from compressed air.

[0002]

2. Description of the Related Art Conventionally, for example, a compressed air drying device described in Japanese Patent Laid-Open No. 3-86207 has a spiral swirling compressed air sent from a compressor,
The cyclone effect (centrifugal action) separates condensed water in compressed air. This one is equipped with a drain cock for discharging the separated condensed water, but it is very inconvenient because the drain cock must be manually operated during drainage.

Therefore, for example, a compressed air drying device used in an air suspension for automobiles is designed to discharge water by an electromagnetic valve in order to automatically perform a draining operation by an external signal.

[0004]

However, in the structure using the solenoid valve as the drain valve, since the solenoid valve is constantly exposed to water and humidity, rust occurs on the solenoid valve,
Freezing may occur in the winter and the solenoid valve may malfunction.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a compressed air drying device capable of preventing malfunction of the drain valve due to rust and freezing and improving reliability of automatic drainage. To provide.

[0006]

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 water in the compressed air introduced from the inlet port. A water separation chamber for separation, a drying chamber containing a desiccant for adsorbing moisture in the compressed air introduced from the water separation chamber, and an outlet port for sending the dried compressed air from the drying chamber to a predetermined place In the above, a valve chamber provided in communication with the water separation chamber and having a drain port at the bottom and a drain valve movably accommodated in the valve chamber are provided, and the valve chamber is provided by the drain valve. The chamber is partitioned into a first pressure chamber in which the pressure of the water separation chamber acts and a second pressure chamber in which the pressure of the drying chamber acts through an exhaust throttle. Communicate / shut off the second pressure chamber to the atmosphere For opening and closing the drain port by moving the drain valve by the pressure difference between the first pressure chamber and the second pressure chamber by opening and closing the solenoid valve. It is configured as follows.

[0007]

In the compressed air drying operation, the electromagnetic valve is closed to shut off the second pressure chamber from the atmosphere, and the high pressure in the drying chamber is applied to the second pressure chamber. As a result, the drain valve keeps the drain port closed. At the time of this compressed air drying, the water in the compressed air introduced from the inlet port is separated in the water separation chamber, the moisture in the compressed air introduced into the drying chamber from this water separation chamber is adsorbed by the desiccant, and then this dry compressed Send air from the outlet port into place.

On the other hand, when the water accumulated at the bottom of the water separation chamber is discharged, the solenoid valve is opened so that the second pressure chamber communicates with the atmosphere. As a result, the compressed air in the second pressure chamber is discharged into the atmosphere through the solenoid valve, and the pressure in the second pressure chamber instantly drops to atmospheric pressure. Along with this, the pressure in the first pressure chamber is reduced. In order for the pressure to decrease, the compressed air in the first pressure chamber must be discharged through the first pressure chamber → water separation chamber → drying chamber → exhaust throttle → second pressure chamber → solenoid valve → atmospheric path. Moreover, since the volume of the drying chamber is relatively large, even if the solenoid valve is opened, the exhaust throttle restricts the discharge of the compressed air from the first pressure chamber, and the pressure in the first pressure chamber is not immediately increased. It does not fall and is kept at high pressure for a while. For this reason, a large pressure difference is generated between the first pressure chamber and the second pressure chamber for a while after the solenoid valve is opened, and the drain valve is moved by this pressure difference to open the drain port. The drain port communicates with the first pressure chamber and the water separation chamber. As a result, the water accumulated in the water separation chamber and the first pressure chamber is quickly discharged by being placed on the flow of compressed air that is vigorously blown out from the drain port.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 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. This entrance port 13
In order to prevent the backflow of compressed air, the spring 1
A check valve 15 is provided which is energized by 4. An inlet passage 16 communicating with the check valve 15
Is formed, and a cylindrical water separation chamber 17 is formed in communication with the inlet passage 16. The positional relationship between the water separation chamber 17 and the inlet passage 16 is as shown in FIG.
6 is formed at an eccentric position with respect to the cylindrical water separation chamber 17, and compressed air is blown from the inlet passage 16 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, a funnel-shaped introduction pipe 18 for introducing compressed air from which condensed water has been separated into the drying chamber 11 is provided in the water separating chamber 17. 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.

A desiccant 21 for adsorbing moisture in the compressed air is contained in the drying chamber 11. This desiccant 2
1 is a filter 22, 23 and a perforated plate 24,
25 is held so as to be sandwiched between the drying chamber 1 and
Spaces 11a and 11b are secured in the upper part and the lower part of the unit 1. Then, in the upper space 11a, the upper porous plate 24
A spring 26 for urging the lower part is stored.

Further, the upper cover 11c of the drying chamber 11 is formed with an outlet port 27 for sending the compressed air dried in the drying chamber 11 to, for example, a pressure storage tank (not shown). The outlet port 27 and the upper space 11a of the drying chamber 11 are provided with a filter 28 and a rubber check valve 2
It is communicated via 9. The check valve 29 is pushed up by the pressure of the drying chamber 11 to open the outflow hole 30, and the compressed air in the upper space 11a of the drying chamber 11 is routed from the filter 28 to the outflow hole 30 (check valve 29) to the outlet port 27. Drain with. Also, check valve 2
A decompression throttle 31 is provided in parallel with the outflow hole 30 of 9 so that the compressed air on the accumulator tank gradually flows into the drying chamber 11 through the decompression throttle 31 when the desiccant 21 described later is regenerated.

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 fixed to the lower peripheral edge of the drain valve 35, and the seal member 41 is in close contact with the seat portion of the drain port 32.

On the other hand, as shown in FIG. 3, a solenoid valve 42 for connecting / disconnecting the second pressure chamber 37 to the atmosphere is provided on the side of the valve chamber 33. The solenoid valve 42 has an upstream chamber 44 communicating with the second pressure chamber 37 through a passage 43.
And a downstream chamber 46 communicating with the atmosphere through the passage 45. A valve body 48 is provided at the tip of the plunger 47 of the solenoid valve 42, and when the magnet coil 49 is not energized, the plunger 47 moves the spring 50.
Thus, the valve body 48 is projected and is held in a state in which the upstream chamber 44 and the downstream chamber 46 are blocked. On the other hand, when the magnet coil 49 is energized, the plunger 47 causes the spring 5 to move.
The valve body 48 is sucked against 0, and the valve body 48 brings the upstream chamber 44 and the downstream chamber 46 into communication with each other.

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 solenoid valve 42 is not energized and the solenoid valve 42 is closed. In this state, the valve body 48 is held in the closed position by the spring 50 in the solenoid 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 31 to the outlet port 27. And reaches the predetermined pressure storage tank (not shown) through the outlet port 27.

(2) During drainage (when the compressed air drying operation is completed)
Operation of When the pressure accumulation tank 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 solenoid valve 42 is energized to open the solenoid valve 42. As a result, the plunger 47 of the solenoid valve 42 causes 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
Pressure chamber 37 → solenoid valve 42 → outlet air, and the drying chamber has a relatively large volume.
Even if the solenoid valve 42 is opened, the exhaust throttle 38 restricts the discharge of the compressed air from the first pressure chamber 36, and the pressure in the first pressure chamber 36 does not immediately drop, but is kept high for a while. Be done. Therefore, the first valve is opened for a while after the solenoid valve 42 is opened.
A large pressure difference is generated between the pressure chamber 36 of the second pressure chamber 37 and the pressure chamber 36 of the second pressure chamber 37.
The drainage port 32 is opened by moving the drainage port 32 upward, and the drainage port 32 is communicated 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 solenoid 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 during Regeneration of the Desiccant 21 When regenerating the desiccant 21, the solenoid 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 because the pressure is also discharged through the path of the second pressure chamber 37 → the solenoid valve 42 → the atmosphere.

Due to the pressure drop in the drying chamber 11, the pressure on the accumulator tank side (the pressure on the outlet port 27 side) is reduced.
Becomes higher than the pressure in the drying chamber 1 due to the pressure difference, and a small amount of compressed air flows from the accumulator tank side through the pressure reducing diaphragm 31.
Backflow into 1. Since the compressed air in the drying chamber 11 has a low pressure, the compressed air expands in volume while being decompressed by the decompression throttle 31, and becomes dry air having a lower humidity than in the high pressure state, and the adsorbed moisture is removed from the desiccant 21. The desiccant 21 is regenerated by removing it.

At the beginning of opening the solenoid 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 that, 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 solenoid valve 42, and the atmosphere.

According to the first embodiment described above, the drain valve 35 is opened by the pressure difference between the first pressure chamber 36 and the second pressure chamber 37 during drainage. Eliminates the need for valves. Therefore, a non-magnetic material such as stainless steel or plastic can be used for the drain valve 35, and rust prevention can be achieved. Moreover, since the drain valve 35 is opened by the pressure difference of the compressed air, the opening force of the drain valve 35 becomes several tens [N], and a remarkably large opening force can be secured as compared with the opening force of the solenoid valve. Therefore, even if the drainage valve 35 freezes in the winter, the drainage valve 35 can be opened with a large opening force, and in combination with the above-described circumstances, malfunction of the drainage valve 35 due to freezing or rust can be prevented. .

Further, as described above, since the opening force of the drainage valve 35 due to the pressure difference of the compressed air is as large as several tens [N], even if the pressure of the compressed air fluctuates, a sufficient and sufficient drainage valve 35 can be operated. The opening force can be secured, the drainage valve 35 can be reliably opened, and the reliability of automatic drainage can be improved.

Moreover, after draining, the drain valve 35 and the solenoid valve 4
Since the dry air flows from the drying chamber 11 around the second valve body 48, the surroundings of the drain valve 35 and the valve body 48 of the electromagnetic valve 42 are kept at a low humidity, and rust and freezing are inherently difficult to occur. Becomes
From this aspect as well, the reliability of automatic drainage can be improved.

In the first embodiment described above, the drain valve 35
Although a poppet type valve is used as the valve, any type of valve may be used as long as it is a valve that opens and closes due to the pressure difference of compressed air. For example, a second embodiment of the present invention shown in FIG. As described above, the diaphragm type drain valve 51 may be adopted. In this second embodiment, the diaphragm type drain valve 5
The outer peripheral edge of 1 is fixed to the peripheral wall of the valve chamber 33, and the inside of the valve chamber 33 is
The drain valve 51 divides into a first pressure chamber 52 and a second pressure chamber 53. A spring 54 for urging the drainage valve 51 downward is housed in the second pressure chamber 53, and the drainage valve 51 is urged by the urging force of the spring 54.
However, the drain port 5 formed upward on the bottom of the valve chamber 33
5 is kept closed. The other structure is the same as that of the first embodiment described above.

Also in this second embodiment, during drainage,
The drain valve 51 is opened by the pressure difference between the first pressure chamber 52 and the second pressure chamber 53, and the same effect as that of the first embodiment described above can be obtained.

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

[0035]

As is apparent from the above description, according to the present invention, the drain valve is opened by the pressure difference of the compressed air during drainage, so that the solenoid valve is not used as the drain valve. A non-magnetic material such as stainless steel or plastic can be used to prevent rust, and a remarkably large opening force can be secured compared with the opening force of the solenoid valve. As a result, malfunction of the drainage valve due to freezing or rust can be prevented, and even if the pressure of the compressed air fluctuates, a sufficient and sufficient opening force of the drainage valve can be secured, and the reliability of automatic drainage can be improved.

Moreover, after the drainage, since the dry air flows from the drying chamber around the valve bodies of the drainage valve and the solenoid valve, the surroundings of the drainage valve and the solenoid valve valve body are kept at a low humidity and rusted or rusted. Freezing is inherently less likely to occur, and this aspect also improves the reliability of automatic drainage.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention, which corresponds to I- of FIG.
Sectional view shown along line I

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.

FIG. 6 is a sectional view of a valve chamber portion showing a second embodiment of the present invention.

[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, 31 is a pressure reducing throttle, 32 is a drainage 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 a solenoid valve, 48 is a valve element, 51 is a drain valve. , 52 is a first pressure chamber, 53 is a second pressure chamber, 54 is a spring, and 55 is a drain port.

Claims (1)

[Claims] 1. An inlet port for introducing compressed air to be dried, a water separation chamber for separating water in the compressed air introduced from the inlet port, and adsorption of moisture in the compressed air introduced from the water separation chamber. In a compressed air drying device having a drying chamber containing a desiccant for drying, and an outlet port for sending dry compressed air from the drying chamber to a predetermined place, the compressed air drying device is provided in communication with the water separation chamber and drained to the bottom. A valve chamber having a port; and a drain valve that is movably accommodated in the valve chamber and opens and closes the drain port according to the movement, and the valve chamber is divided into two chambers by the drain valve. A first pressure chamber in which the pressure of the water separation chamber acts, and
A second pressure chamber in which the pressure of the drying chamber acts via an exhaust throttle is provided, and a solenoid valve for communicating and blocking the second pressure chamber with the atmosphere is provided, and the solenoid valve is opened and closed. The drain valve by the first
The pressure chamber between the second pressure chamber and the second pressure chamber,
A compressed air drying device characterized in that the drain port is configured to be opened and closed.