JPH0330813A - Compressed air drying apparatus - Google Patents

Abstract

PURPOSE:To prevent lowering of drying capacity by providing movable members deformable and shiftable due to pressure differential and an air chamber divided by the movable members. CONSTITUTION:A drying device 10 receives compressed air from an air compressor 50 through an inlet opening 20 and removes compressor oil therefrom with a filter 32. Water is then removed from the compressed air with a desiccating agent 30 and this water-free compressed air is supplied through a check valve 40 into a purge tank 18 and then through an outlet opening 22 into an outside air storage tank 70. The dry compressed air in the air storage tank 70 is supplied to operate air brake device, etc., and the compressed air in the purge tank 18, at the time of recycling, is sent through a constricted passage 42 for use in the regeneration of the desiccating agent 30. This permits a large amt. of the compressed air to be dried.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a compressed air drying device used in a pneumatic circuit, for example, an air brake circuit of a vehicle, etc. This invention relates to effective techniques for avoiding the effects of pulsating pressure.

(Prior art) This type of compressed air drying device is, for example,
As Publication No. 21732 shows: - in the shell an inlet connected to an air compressor and an outlet connected to an air reservoir;
A desiccant is placed between the inlet and the outlet to absorb moisture in the compressed air, and a drain discharge valve is provided in the discharge passage that communicates the inlet side of the desiccant with the outside air and opens in response to an external signal. and a purge tank formed on the desiccant air storage tank side.

These devices typically first remove compressor oil and dust from the compressed air supplied from the inlet through a filter placed near the inlet, and then remove moisture or humidity through a layer of desiccant. .

(Problem to be Solved by the Invention) By the way, the compressed air discharged by the air compressor has pulsations, and the pulsating pressure causes the filter near the inlet, the desiccant layer, Alternatively, it may act directly on the sealing member that seals between parts, causing damage to them.

Especially in the case of a device applied to a vehicle, the air compressor is driven by the power of the vehicle's engine.

When the vehicle is running at high speed, the pulsating pressure becomes considerably larger than during normal running, and the risk of damage is also large.

As a technique to avoid the effects of pulsating pressure as described above, the applicant of the present application previously proposed a technique in which a specific rubber membrane with slits is placed in the middle of the air flow path leading from the inlet to the desiccant. (Utility Application No. 161483-1983). The slit is
It is normally closed, but opens when a pressure difference is created across the rubber membrane. That is, in the previous technology, the pulsating pressure was reduced by the constricting action of the slit.

In order to more effectively reduce pulsating pressure using the technique related to the above proposal, it is necessary to enhance the throttling effect of the slit. In such a case, the slit itself becomes a flow resistance, so it is not suitable for drying a large amount of compressed air in a short period of time.

This invention was made in consideration of the above points,
It is an object of the present invention to provide a technique that can effectively avoid the influence of pulsating pressure from an air compressor without reducing drying processing capacity.

(Summary of the Invention) In the present invention, as shown in FIG. 1 corresponding to one embodiment, there are two pressure receiving parts, a movable member 107 that deforms or moves due to a pressure difference, and a movable member 107 that is divided by the movable member 107. One of the air chambers 105 is connected to the purge tank 18, and the other one is connected to the purge tank 18.
06 are respectively connected to the entrance 20 side.

Since the movable member 107 does not block the flow path of the compressed air to be dried, the drying processing capacity is not reduced. However, due to the buffering effect of the purge tank 18 as a buffer chamber, the problematic pulsating pressure can be effectively reduced.

(Example 1) See FIG. 1 This first example shows a structure in which a pulsation absorbing device 100 is attached to the outside of a compressed air drying device i10. Therefore, first, the main body portion of the compressed air drying device 10 will be explained, and then the portion of the pulsation absorbing device 100 will be explained.

The compressed air drying device 10 has a relatively small-sized dryer 14 and a casing 16 surrounding it on the upper surface of a base member 12 that can be used as a mounting base. The housing 14a of the dryer 14, like the casing 16, has a circular cross section. Since both are arranged concentrically, there is a space 18 inside the casing 16 surrounding the housing 14a.
are divided. This space 18 is used as a purge space, ie, a purge tank, for storing compressed air for regeneration.

The base member 12 has an inlet 20 connected to an air compressor 50.
, an outlet 22 connected to the air storage tank 70, and a discharge passage 24 for draining drain that communicates the inlet 20 side with the outside air. The entrance 20 communicates with a surrounding entrance cavity 26,
A plurality of radial protrusions 26a are formed on the side wall of the entrance cavity 26. The protrusion 26a increases the degree of contact of the compressed air supplied from the inlet 20 with the side wall. The upper part of this inlet cavity 26 opens onto the upper side of the base member 12, while the lower part communicates with the outside through a discharge passage 24. A drain discharge valve 28 that can be opened in response to an external command is arranged in the discharge passage 24 . This drain discharge valve 28 is a valve for draining the drain, and is also an opening valve to the outside atmosphere for the regeneration cycle of the desiccant 30.

The desiccant 30 is inside the housing 14a of the dryer 14. The housing 14a of the dryer 14 is partially constricted on the bottom side. A ring-shaped filter 32 is placed inside the small diameter portion 14b, and a desiccant 30 is accommodated in the upper part of the filter 32. Since the desiccant 30 is granular, a breathable sheet 34 and a perforated plate 36 are placed above and below it.
are provided for each. The housing 14a itself is
The small diameter portion 14b fits into the hole 12a of the base member 12,
Furthermore, the flange 14c fixed to the housing 14a is attached to the base member 12 with bolts 38 or the like.

Such a compressed air drying device 10 receives compressed air discharged from an air compressor 50 into an inlet 20.

Compressor oil and the like are removed using a filter 32 and the like, and then moisture is removed using a desiccant 30. The compressed air from which moisture has been removed is then passed through the check valve 40 to the purge tank 18 and the outlet 22 to the external air storage tank 70.
supply to. The dry compressed air in the air storage tank 70 is used to operate an air brake device, etc., and the compressed air in the purge tank 18 is used to regenerate the desiccant 30 through the throttle passage 42 during the regeneration cycle. Although not shown in Figure 5, there is an outlet 22 between the outlet 22 and the air storage tank 70.
A check valve is arranged to allow flow from the side to the air storage tank 70 side and prohibit the reverse flow.

Next, the air compressor 50 and the inlet 2 of the compressed air drying device 10
The pulsating urine absorption device 100 located between 0 and 0 will be described.

The pulsating urine absorption device 100 includes a casing 102 divided into upper and lower halves. The casing 102 includes an upper casing 102a and a lower casing 102b, which are integrally attached by a member 104 with a seal ring 103 in between.

Inside the casing 102, there are two air chambers 10 above and below.
5,106 are classified. The upper air chamber 105 is
Piping 1 extending from the upper casing 102a of the pulsating urine absorption device 100 to the casing 16 of the compressed air drying device 10
It is connected to the purge tank 18 by 01. Also,
The lower air chamber 106 becomes a flow path for supplying compressed air sent from the air compressor 50 to the inlet 20 of the compressed air drying bag W10. On both sides of the lower casing 102b,
On the one hand there is an air inlet 120 which is connected by piping to the air compressor 50 and on the other hand there is an air outlet 122 which is connected by a nipple 121 to the inlet 20 of the compressed air drying device 10 . The lower air chamber 106 is.

This is a chamber located between the air population 120 and the air outlet 122.

What divides the inside of the casing 102 is a rubber diaphragm 107 that is a movable member. diaphragm 10
7 is placed on a perforated plate 108 having a large number of holes 108a, and each peripheral portion is attached to the upper casing 1 along with the perforated plate 108.
02a and the lower casing 102b. The diaphragm 107 has two upper and lower air chambers 105.
, 106 can be deformed or moved, but downward deformation is restricted by the perforated plate 108. This perforated plate 108 supports the diaphragm 107 and prevents it from being damaged when the pressure in the lower air chamber 106 suddenly decreases during the regeneration cycle of the desiccant 30. On the other hand, the diaphragm 107 can deform upwardly by overcoming the biasing force of the spring 109. spring 109
is supported between a spring receiver 110 placed on the diaphragm 107 and the inner wall of the upper casing 102a. The load of this spring 109 is
This value is commensurate with the ventilation resistance that 0 has.

Further, there is a center hole 130 in the center of the diaphragm 107, which is a movable member, and a valve 140 is provided in the center hole 130. Valve 140 is opposite actuating rod 152 of alarm switch 150, which is a bushing switch. Therefore, if the filter 32 and desiccant 30 in the compressed air drying device 10 become clogged with sludge, tar, etc. and a large pressure difference occurs between the two upper and lower air chambers 105 and 106, the diaphragm 107 deforms and the upper Move to valve 14
0 applies force to the actuating rod 152 of the alarm switch 150 to switch the switch, and at the same time, the actuating rod 152
Valve 140 is opened by receiving the force from 2. Therefore, since the valve 140 serves as a bypass, even if an abnormality such as clogging occurs, the operation of the air-operated equipment connected to the air storage tank 70 will not be disabled. Note that the signal from the alarm switch 150 is connected to an alarm device such as a buzzer in the driver's seat of the vehicle through a lead wire connected to the connector 154, so the driver can use the alarm to detect abnormalities in the function of the compressed air drying device 10. You can know.

Now, when compressed air is sent from the air compressor 50, the lower air chamber 106 of the pulsating absorption device 100 has a higher pressure than the upper air chamber 105 because the pulsating pressure of the compressed air is large. vibrates due to the pulsating pressure, effectively damping the pulsating pressure. At this time,
Since the pulsation absorption device 100 uses the purge tank 18 as a buffer chamber, the pulsation pressure is sufficiently attenuated. In addition, the pulsating pressure absorber W100 always uses a compressed air drying bag! ! Since a sufficiently large flow path to the inlet 20 side of 10 is secured,
Compressed air dryer! The drying capacity of 10 is not reduced.

Note that the upper air chamber 105 and the purge tank 18 can also be connected using a passage provided in the base member 12. This makes it possible to eliminate unnecessary work such as removing piping during maintenance of the compressed air drying device 10.

Further, although the illustrated embodiment is provided with an alarm mechanism including an alarm switch 150, the alarm mechanism may be omitted by providing a stem for opening the valve 140 on the inner wall of the upper casing 102a.

(Embodiment 2) Refer to FIG. 2 In a second embodiment, the main part of which is shown in FIG. 2, a pulsation absorbing device 200 is incorporated inside a compressor drying device 10'. The overall structure of the compressor drying device 10' is similar to that of the first embodiment, but in this example, the base member 212 is divided into an upper member 212a and a lower member 212b, and the upper member 2
The housing 20 of the pulsatility absorbing device 200 is a part of the pulsating absorber 12a.
I am trying to form 2. The housing 202 has an opening at the bottom and a side wall facing the inlet 20.

The pulsation absorbing device 200 inside the housing 202 is also almost the same as in the first embodiment, and includes a diaphragm 207 as a movable member, a perforated plate 208 that supports the diaphragm 207, and a spring 209 suitable for ventilation resistance. The housing 20 has a valve 240 etc. that opens when it is clogged.
One air chamber 20 above the diaphragm 207 in 2
5. Below the diaphragm 207 there is another air chamber 206 occupying part of the inlet cavity. diaphragm 207
The upper air chamber 205 is connected to the upper member 212 of the base member 212.
It communicates with the purge tank 18 through a passage 201 formed in a and an outlet passage 22a leading to an outlet 22. Further, the perforated plate 208 is supported by a stopper ring 260 provided near the opening, and furthermore, the valve 208 is supported by a stopper ring 260 provided near the opening.
40 is opened by a stem 252 at the center of the disc located at the back of the housing 202.

In this second embodiment as well, the effect of reducing pulsating pressure by the pulsatility absorbing device 200 is the same as in the first embodiment. In addition, in the second embodiment, during maintenance, the lower member 2
By removing 12b, parts of the internal pulsation absorbing device 200 can be replaced.

(Example 3)...See Figure 3 This third embodiment is similar to the second embodiment.

This is an example with a built-in pulsation absorption device. However, the third embodiment is an integral type having one base member 312, and the housing 302 of the pulsation absorbing device 300 is formed in a part of the base member 312.

The housing 302 has an opening at the top, and from the opening,
Sequentially, the spring 309, the diaphragm 307 which is a movable member, the perforated plate 308, and the stopper ring 360.
is set. The central valve 340 of the diaphragm 307 is opened by a protrusion 352 on the bottom of the housing 302. Further, one air chamber 305 divided by the diaphragm 307 is connected to a passage 305 formed in the base member 312.
1 and an outlet passage 22a that communicates with the purge tank 18.

In this example as well, the effect of reducing pulsating pressure is the same as in the previous example.

In each of the embodiments, a diaphragm is used as the movable member, but a movable piston may also be used as the movable member.

(Effect of the invention) In this invention, two air chambers 105 and 106 are divided by a diaphragm 107 which is a movable member, one air chamber 105 is connected to the purge tank 18, and the other air chamber 106 is connected to the inlet 20 side. Since the purge tank 18 is used as a buffer chamber to effectively reduce pulsating pressure, the flow path on the inlet 20 side is always secured by the other air chamber 106, so that a large amount of compression can be achieved. It can also be applied when drying air.

[Brief explanation of drawings]

FIG. 1 is an overall cross-sectional structural diagram showing a first embodiment of the present invention. FIG. 2 is a sectional view showing the main parts of the second embodiment, and FIG. 3 is a sectional view showing the main parts of the third embodiment. DESCRIPTION OF SYMBOLS 10... Compressed air dryer, 18... Purge tank, 20... Inlet, 22... Outlet, 28... Drain release valve, 30... Desiccant, 50... Air compressor ,7
0... Air storage tank, 100... Pulsating absorption device, 10
5.106...Air chamber, 107...Movable member.

Claims (1)

[Claims] 1. An inlet connected to the air compressor, an outlet connected to the air storage tank, a desiccant that absorbs moisture in the compressed air and is placed between the inlet and the outlet, and an inlet side of the desiccant. In a compressed air drying device that has a drain discharge valve that is installed in a discharge passage that communicates with the outside air and opens in response to an external signal, and a purge tank that is formed on the desiccant air storage tank side, there are two pressure receiving parts. , a compressed air system comprising a movable member that deforms or moves due to a pressure difference, and two air chambers separated by the movable member, one of which is connected to the purge tank and the other to the inlet side. drying equipment.