Collected fluid discharge system

Abstract

Collected liquid discharge system (9), comprising: an oil separator (3) which separates gas and liquid in an oil-containing fluid to collect oil-containing liquid, and a gas supply source which supplies gas to the oil separator (3), the oil separator (3) comprising: an oil trap (40) which collects liquid; a reservoir that stores the liquid collected by the oil trap (40); a collected liquid discharge port (3c) that discharges the liquid stored in the reservoir; a liquid inlet opening (3a) through which liquid flows; an air discharge opening (3b) which discharges air separated from the fluid; and a three-way valve (10) which increases the internal pressure of the reservoir and which is connected to a line (10d) connected to the liquid inlet port (3a) or the air outlet port (3b), a gas supply passage connected to the gas supply source, and a liquid outlet passage (8) which supplies liquid to the oil separator (3), wherein the three-way valve (10) is configured to switch between a first connection state in which the three-way valve (10) connects the liquid discharge passage (8) to the liquid inlet opening (3a) or the air discharge opening (3b), and a second connection state in which the three-way valve (10) connects the gas supply passage to the liquid inlet opening (3a) or the air discharge opening (3b), wherein in the first connection state, the fluid flowing through the three-way valve (10) flows from the liquid discharge passage (8) to the liquid inlet port (3a) or the air discharge port (3b), and wherein in the second connection state, the fluid flowing through the three-way valve (10) flows from the gas supply passage to the liquid inlet port (3a) or the air outlet port (3b).

Description

[0001] The present invention relates to a collected liquid discharge system that collects liquid and discharges the collected liquid.

[0002] For example, vehicle systems such as brakes and suspensions operate various devices using compressed air. Some of these systems include a compressed air drying system located downstream of the compressor to remove water and oil from the compressed air.

[0003] An example of a known compressed air drying system includes an air dryer containing a desiccant and an oil separator (see, for example, JP 2013 - 234632 A). The oil separator collects liquid containing oil and water, which is discharged from the air dryer by regenerating the desiccant.

[0004] DE 11 2014 000 999 B4 describes an oil separator with a housing body and an impact element provided in the housing body, wherein purge air is introduced from an air dryer into the housing body and impacts the impact element, whereby the oil content is separated from the introduced purge air and a drain containing the oil content is captured and collected, while clean air is discharged, wherein a drain discharge opening is provided at the bottom portion of the housing, from which accumulated drain is discharged. Furthermore, a detection section is provided inside the housing body. The detection section is configured to detect the drain amount in the housing body, and based on the detection result, the detection result is output to a drain amount notification element. The impact element is provided in an upper portion of the housing body.The effluent is stored in a portion of the housing body that is lower than the baffle. A lower end of the detection portion is located below a bottom surface of the baffle, and the detection portion is further configured to detect that the effluent has accumulated near the bottom surface, which represents a capacity limit.

[0005] US 4,234,327 A discloses an air dryer for a compressed air system. The air dryer comprises a vertical cylindrical tank with a downward-facing inlet pipe, which has a liquid droplet-forming end at the bottom. The tank has a manual drain valve at the bottom. A partition wall at the top ensures that the compressed air is separated from any liquid.

[0006] EP 3 581 800 A1 describes an oil separator. This oil separator comprises a housing with an inlet and an outlet for air, as well as a baffle element provided within the housing. Oil-containing air is introduced into the housing through the inlet and impacts the baffle element, separating the oil from the introduced air and recovering it. The outlet opens horizontally across the housing. The oil separator also comprises an L-shaped elbow attached to the outlet. The elbow protrudes horizontally from the outlet and is curved upwards.

[0007] Conventional oil separators drain the collected liquid using gravity, so it takes a long time to drain the collected liquid.

[0008] Accordingly, it is an object of the present invention to provide a collected liquid discharging system that discharges collected liquid within a short time.

[0009] This object is achieved by a collected liquid discharge system having the features of claim 1. Advantageous further developments are specified in the subclaims.

[0010] In particular, a collected liquid discharge system according to the invention comprises an oil separator that separates gas and liquid in an oil-containing fluid to collect oil-containing liquid, and a gas supply source that supplies gas to the oil separator, wherein the oil separator comprises: an oil trap that collects liquid; a reservoir that stores the liquid collected by the oil trap; a collected liquid discharge port that discharges the liquid stored in the reservoir; a liquid inlet port through which liquid flows in; an air discharge port that discharges air separated from the fluid; and a three-way valve that increases the internal pressure of the reservoir and is connected to a conduit connected to the liquid inlet port or the air discharge port, a gas supply passage connected to the gas supply source, and a liquid outlet passage that supplies liquid to the oil separator.wherein the three-way valve is configured to switch between a first connection state in which the three-way valve connects the liquid discharge passage to the liquid inlet port or the air discharge port, and a second connection state in which the three-way valve connects the gas supply passage to the liquid inlet port or the air discharge port. In the first connection state, the fluid flowing through the three-way valve flows from the liquid discharge passage to the liquid inlet port or the air discharge port, and in the second connection state, the fluid flowing through the three-way valve flows from the gas supply passage to the liquid inlet port or the air discharge port.

[0011] With this configuration, when the oil-containing liquid is collected by the oil separator, the three-way valve switches the flow direction in a section upstream of the oil separator so that fluid flows from the liquid discharge passage to the oil separator. When the liquid collected by the oil separator is discharged, the three-way valve switches the flow direction in the section upstream of the oil separator so that gas flows from the gas supply passage to the oil separator. Thus, gas supplied from the gas supply source is caused to flow into the oil separator to increase the internal pressure of the oil separator. The increased pressure forces the stored liquid through the collected liquid discharge port. For this reason, the liquid collected in the oil separator is discharged within a short time.

[0012] The present invention provides a collected liquid discharging system that discharges collected liquid within a short time. Fig. 1 is a schematic view showing a collected liquid discharge system according to a first embodiment. Fig. 2 is a schematic view showing the collected liquid discharge system according to the first embodiment. Fig. 3 is a side view of the oil separator according to the first embodiment. Fig. 4 is a plan view of the oil separator according to the first embodiment. Fig. 5 is a cross-sectional view of the oil separator according to the first embodiment when the oil separator collects liquid. Fig. 6 is a cross-sectional view of the oil separator according to the first embodiment when the oil separator discharges collected liquid. Fig. 7 is a schematic view showing a collected liquid discharge system according to a second embodiment. Fig. 8 is a schematic view showing a collected liquid discharge system according to a third embodiment. Fig. 9 is a schematic view showing the structure of a collected liquid discharge system according to a modification. Fig. 10 is a schematic view showing the structure of a collected liquid discharge system according to a modification. First embodiment

[0013] In the following, a first embodiment is described with reference to Fig. 1 to 6. In this embodiment, a collected liquid discharge system is provided as part of a compressed air drying system that dries compressed air supplied by a compressor. The compressed air drying system is mounted on a vehicle with an internal combustion engine.

[0014] As in Fig. As shown in Figure 1, the compressed air drying system comprises a compressor 1, an air dryer 2, and an oil separator 3. The compressor 1 is coupled to the vehicle's internal combustion engine. The compressed air supplied by the compressor 1 contains water and oil, which may originate from a lubricant, for example. The water is contained in the compressed air primarily as water vapor, and the oil is contained in the compressed air primarily as oil mist.

[0015] The air dryer 2 contains a desiccant 4 and a filter (not shown) for capturing oil mist. The air dryer 2 includes an inlet 2a and an outlet 2b. The compressed air supplied from the compressor 1 flows in through the inlet 2a. The compressed air from which water and oil have been removed, or the dried compressed air, flows out through the outlet 2b. The dried compressed air that has flowed out through the outlet 2b is stored in the air tank 5. The dried compressed air stored in the air tank 5 is supplied to, for example, a braking system or an air suspension system.

[0016] The air dryer 2 performs not only a charge mode operation for collecting water and oil contained in compressed air, but also a discharge mode operation in which, for example, water and oil collected by the desiccant 4 are discharged to the outside to regenerate the desiccant 4. During the discharge mode, fluid containing water and oil and air (purge air) is discharged to the oil separator 3 through a liquid discharge port 2c of the air dryer 2.

[0017] The oil separator 3 includes a liquid inlet port 3a connected to the liquid outlet port 2c of the air dryer 2, and an air outlet port 3b. The oil separator 3 separates gas and liquid in the fluid flowing in through the liquid inlet port 3a. The gas, which is the separated clean air, is discharged into the atmosphere through the air outlet port 3b, and the collected liquid is stored inside the oil separator 3.

[0018] A collected liquid discharge port 3c for discharging collected liquid to the outside is provided in the bottom part of the oil separator 3. A collected liquid discharge hose 3d is connected to the collected liquid discharge port 3c. When no collected liquid is discharged from the oil separator 3, the collected liquid discharge hose 3d is fixed at a predetermined position so that the outlet of the collected liquid discharge hose 3d is positioned vertically above the collected liquid discharge port 3c. When collected liquid is discharged from the oil separator 3, the outlet of the collected liquid discharge hose 3d is positioned vertically below the collected liquid discharge port 3c of the oil separator 3.

[0019] Furthermore, a liquid discharge passage 8 is connected to the liquid discharge port 2c of the air dryer 2. A directional control valve, which is a three-way valve 10 in this embodiment, is connected to the outlet of the liquid discharge passage 8. The three-way valve 10 corresponds to a mechanism for increasing the internal pressure of a reservoir provided in the oil separator 3 and storing the collected liquid. The three-way valve 10 includes a first inlet 10a connected to the liquid discharge port 2c of the air dryer 2 via the liquid discharge passage 8, a second inlet 10b to which air is supplied from the outside, and an outlet 10c connected to the liquid inlet port 3a of the oil separator 3. The second inlet 10b is connected to an air supply device 6 via an air supply passage 7.The air supply device 6 is, for example, an air tank provided for discharging the collected liquid. The outlet 10c of the three-way valve 10 is connected to the liquid inlet port 3a of the oil separator 3 via a conduit, which in this embodiment is a coupling passage 10d. The oil separator 3 and the air supply device 6 configure a collected liquid discharge system 9.

[0020] The three-way valve 10 switches the direction of an L-shaped flow passage in the three-way valve 10 according to a difference between the pressure at the first inlet 10a and the pressure at the second inlet 10b. The three-way valve 10 switches the connection state between a first mode in which the first inlet 10a is connected to the outlet 10c and a second mode in which the second inlet 10b is connected to the outlet 10c. The first inlet 10a is not connected to the second inlet 10b. In the first mode, the fluid flowing through the three-way valve 10 has an L-flow pattern (see Fig. 1) from the first inlet 10a to the outlet 10c. And in the second mode, the fluid flowing through the three-way valve 10 has an L-flow pattern from the second inlet 10b to the outlet 10c (see Fig. 2).

[0021] When the fluid containing liquid is discharged from the air dryer 2 via the fluid discharge passage 8, the three-way valve 10 switches the flow direction so that the fluid flows from the first inlet 10a to the outlet 10c. Accordingly, the fluid containing liquid flows into the liquid inlet port 3a of the oil separator 3 via the coupling passage 10d.

[0022] If, as in Fig. 2, the liquid collected in the oil separator 3 is discharged, a supply valve (not shown) of the air supply device 6 is opened to supply air into the oil separator 3 via the air supply passage 7. In this case, the three-way valve 10 switches the flow direction so that air flows from the second inlet 10b to the outlet 10c. This increases the pressure of the air flowing into the oil separator 3 to push the collected liquid to discharge it from the collected liquid discharge port 3c.

[0023] In the following, the structure of the oil separator 3 is described with reference to Fig. 3 to 5.

[0024] As in Fig. As shown in Figure 3, the oil separator 3 includes a cylindrical housing 11 having a closed end and a lid 12 sealing the opening portion of the housing 11. The above-described collected liquid discharge port 3c is provided at the bottom portion of the housing 11.

[0025] The cover 12 includes the air outlet opening 3b, from which purified air is discharged. The air outlet opening 3b is connected to an air outlet hose 20, which discharges purified air into the atmosphere, via an outlet coupling member 19. The cover 12 further includes a mounting plate 29 that secures the oil separator 3 to a receiving body.

[0026] As in Fig. As shown in Figure 4, the lid 12 includes the above-described liquid inlet port 3a in addition to the air outlet port 3b. A hose for supplying air discharged from the air dryer 2 is connected to the liquid inlet port 3a via an insertion coupling member 18.

[0027] As in Fig. As shown in Figure 5, a disc-shaped cover 25 is provided between the housing 11 and the cover 12. The housing 11, the cover 25, and the cover 12 are secured to each other by fastening screws 27 in through holes in a flange portion 26 of the housing 11, through holes in the cover 25, and threaded holes in the cover 12.

[0028] The space defined by the cover 25 and the lid 12 functions as a first expansion chamber 22. A communication hole 28 is formed in the central part of the cover 25. Furthermore, a cylindrical receiving member 30 with a lid is fixed to the bottom surface of the cover 25 by means of screws 27. Flange parts 31, 32 are formed at the upper and lower ends of the receiving member 30, respectively. The receiving member 30 is fixed to the cover 25 by inserting the screws 27 through the flange part 31. The space defined by the upper surface of the fixed receiving member 30 and the cover 25 functions as a second expansion chamber 33. The above-mentioned communication hole 28 formed in the cover 25 connects the first expansion chamber 22 to the second expansion chamber 33.

[0029] Through holes 35 are formed at the central portion of an upper wall 34 of the receiving member 30. The through holes 35 and the connecting hole 28 of the cover 25 are formed at positions that are not opposite each other. Through holes 36 are formed at the lower end of the side wall of the receiving member 30 at intervals in the circumferential direction.

[0030] An oil trap 40 is housed in the receiving member 30, which removes oil contained in the purge air. The oil trap 40 collects oil by causing oil particles to collide against the oil trap 40. In this embodiment, the oil trap 40 is formed from a porous plastic sponge (urethane foam). Plates 43 with numerous through-holes are provided on the upper and lower surfaces of the sponge.

[0031] A retaining disc 45 for retaining the oil trap 40 is attached to the flange portion 32 formed at the lower end of the receiving member 30 by means of screws 46. The retaining disc 45 has a diameter substantially equal to the inner diameter of the housing 11. The retaining disc 45 includes through holes 47 that allow, for example, the liquid oil collected by the oil trap 40 to drip off.

[0032] A reservoir, which in this embodiment is a collected liquid storage part 48, is provided at the lower portion of the housing 11 and stores the collected liquid that has dripped through the through-holes 47. A heater 49 for heating the stored liquid to evaporate water is provided in the collected liquid storage part 48. The heating of the heater 49 is controlled using a thermostat (not shown).

[0033] In the following, the oil separator 3 with the configuration described above is described with reference to Fig. 5 and Fig. 6 described.

[0034] When fluid containing purge air and liquid is discharged from the air dryer 2, the fluid flows into the liquid inlet port 3a of the oil separator 3 via the three-way valve 10.

[0035] As in Fig. As shown in Figure 5, the purge air flowing in through the liquid inlet port 3a encounters baffles 21 and is then introduced into the first expansion chamber 22 to be expanded. The purge air expanded in the first expansion chamber 22 flows into the second expansion chamber 33 through the communication hole 28 formed in the cover 25 and is expanded in the second expansion chamber 33. The expanded purge air flows through the through-holes 35 in the top wall 34 of the receiving member 30 into the oil trap 40 in the receiving member 30 and passes through the interior of the oil trap 40. This configuration removes oil particles and water from the purge air.

[0036] The liquid water and oil collected by the oil trap 40 moves through the oil trap 40, reaches the upper surface of the retaining disc 45, and drips through the through holes 47 in the retaining disc 45 to be stored in the collected liquid storage part 48. When the collected liquid also flows into the oil separator 3, the liquid moves along the same path as described above, passes through the oil trap 40, and drips into the collected liquid storage part 48. The collected liquid stored in the collected liquid storage part 48 is heated by the heater 49, so that the water is evaporated.

[0037] The purified air, from which water and oil have been removed by the oil trap 40, flows through the through holes 36 in the side surface of the receiving member 30 into the space formed between the receiving member 30 and the housing 11. The air passing through the space passes through a connecting hole 50 in the cover 25 and a connecting part 23 in the lid 12, and is then discharged through the air discharge port 3b.

[0038] The following describes the operation during the discharge of the liquid collected by the oil separator 3. The collected liquid is discharged from the oil separator 3 while the operation of the compressor 1 is stopped by stopping the internal combustion engine of the vehicle. To start the discharge of the collected liquid, the collected liquid discharge hose 3d connected to the oil separator 3 is moved from the predetermined position to open the collected liquid discharge port 3c as described above. The supply valve of the air supply device 6 is opened to supply air into the air supply passage 7. The three-way valve 10 switches the internal flow direction so that air flows from the second inlet 10b to the outlet 10c to supply air to the liquid inlet port 3a of the oil separator 3.

[0039] As in Fig. As shown in Fig. 6, the air supplied from the air supply device 6 passes through the liquid inlet port 3a, the first expansion chamber 22, the second expansion chamber 33, and the oil trap 40 in the same manner as when the liquid-containing fluid is discharged from the air dryer 2. Part of the air passed through the oil trap 40 passes through the space between the receiving member 30 and the housing 11 to be discharged from the air discharge port 3b. The remaining part of the air passed through the oil trap 40 is introduced into the collected liquid storage part 48. As a result, the pressure in the collected liquid storage part 48 is increased, and the pressure increase pushes the collected liquid stored in the collected liquid storage part 48 out through the collected liquid discharge port 3c.Consequently, compared with a case where no air is supplied to the oil separator 3, the flow rate of the collected liquid discharged from the collected liquid discharge port 3c per unit time is increased, so that the collected liquid can be discharged within a short time.

[0040] As described above, the present embodiment offers the following advantages. (1) The three-way valve 10 connected to the air supply device 6 causes the internal pressure of the collected liquid storage part 48 to increase when the collected liquid is discharged from the collected liquid storage part 48 of the oil separator 3. The pressure increase pushes the collected liquid to the collected liquid discharge port 3c. In this way, the liquid collected in the oil separator 3 is discharged within a short time. (2) When liquid discharged from the air dryer 2 with oil contained therein is collected by the oil separator 3, the three-way valve 10 switches the flow direction upstream of the oil separator 3 so that fluid flows from the liquid discharge port 2c of the air dryer 2 to the liquid inlet port 3a of the oil separator 3. And when the liquid collected by the oil separator 3 is discharged, the three-way valve 10 switches the flow direction upstream of the oil separator 3 so that air flows from the oil supply device 6 to the oil separator 3. Thus, the air supplied from the air supply device 6 increases the pressure in the oil separator 3 and pushes the collected liquid stored in the oil separator 3 through the collected liquid discharge port 3c.

[0041] For this reason, the liquid collected in the oil separator 3 is discharged within a short time. Second embodiment

[0042] In the following, an oil separator and a collected liquid discharge system according to a second embodiment will be described with reference to Fig. 7. The description will focus on the differences between the first embodiment and the second embodiment. In the oil separator and the collected liquid discharge system according to this embodiment, the structure of the oil separator differs from that of the first embodiment. In the drawings, the same reference numerals are used for components that are substantially identical to the components of the first embodiment, and repeated descriptions of these components will be omitted here.

[0043] As in Fig. As shown in Figure 7, the oil separator 3 includes an on / off valve 3e located downstream of the air discharge port 3b and, for example, in the center of the air discharge hose 20. The on / off valve 3e stops the discharge of purified air from the air discharge port 3b when the on / off valve 3e is closed, and discharges purified air from the air discharge port 3b when the on / off valve 3e is open. The on / off valve 3e is closed when the discharge of the liquid collected by the oil separator 3 begins.

[0044] The operation of this embodiment is described below.

[0045] When the collected liquid starts discharging, the collected liquid discharge hose 3d connected to the oil separator 3 is moved from the predetermined position to open the collected liquid discharge port 3c as described above. Furthermore, the on / off valve 3e of the oil separator 3 is closed, and the supply valve of the air supply device 6 is opened to supply air to the air supply passage 7. When air is supplied from the air supply passage 7, the flow direction of the three-way valve 10 is switched so that air flows from the second inlet 10b to the outlet 10c.

[0046] The air flowing into the oil separator 3 via the three-way valve 10 passes through the oil trap 40 and is introduced into the collected liquid storage part 48 without being discharged from the air discharge port 3b. Thus, the liquid collected in the collected liquid storage part 48 is pressed with a high pressure and discharged within a short time.

[0047] As described above, this embodiment offers the following advantage in addition to the advantages (1) and (2).

[0048] (3) When the liquid collected in the oil separator 3 is discharged, the air discharge port 3b, which is not connected to the air supply passage 7, is closed. At this time, the pressure in the oil separator 3 is further increased by supplying air through the liquid inlet port 3a, which is connected to the air supply passage 7. For this reason, the collected liquid is discharged within a short time. Third embodiment

[0049] In the following, an oil separator and a collected liquid discharge system according to a third embodiment will be described with reference to Fig. 8. The description will focus on the difference between the first embodiment and the third embodiment. In the oil separator and collected liquid discharge system of this embodiment, the structure of the gas supply source differs from that of the first embodiment. In the drawings, the same reference numerals are used for components that are substantially identical to those of the first embodiment, and repeated descriptions of these components will be omitted here.

[0050] As in Fig. As shown in Fig. 8, the second inlet 10b of the three-way valve 10 is connected to the downstream end of the air tank 5, which stores the dried compressed air flowing from the air dryer 2, via the air supply passage 7. A flow rate control valve 7a, which controls the flow rate of the dried compressed air supplied from the air tank 5 to the oil separator 3, is arranged in the center of the air supply passage 7. Furthermore, a dry air supply passage 5b extends from the air tank 5 to be connected to various systems. An on / off valve 5a for selectively opening and closing a dry air supply passage 5b is arranged in the dry air supply passage 5b. With this configuration, an outside air supply source does not need to be provided, and the air tank 5 provided in the compressed air drying system can be used.

[0051] The operation of this embodiment is described below.

[0052] When the collected liquid is started to be discharged, the collected liquid discharge hose 3d connected to the oil separator 3 is moved from the predetermined position to open the collected liquid discharge port 3c as described above. Furthermore, the on / off valve 5a disposed downstream of the air tank 5 is closed, and the flow rate control valve 7a is opened to supply air to the air supply passage 7.

[0053] A portion of the dried compressed air supplied from the air tank 5 passes through the oil trap 40 and is then discharged from the air discharge port 3b, while the remaining portion of the dried compressed air is introduced into the collected liquid storage portion 48. An increase in pressure in the collected liquid storage portion 48 causes the collected liquid to be forced out through the collected liquid discharge port 3c.

[0054] As described above, this embodiment offers the following advantage in addition to the advantages (1) and (2).

[0055] (4) The air supply passage 7, which is connected to the three-way valve 10, is connected to the air tank 5, which stores the dried compressed air flowing out of the air dryer 2. In this configuration, a dedicated air tank is not required and the existing air tank 5 can be used. Other embodiments

[0056] The embodiments described above may be modified as follows.

[0057] The oil separator 3 may have other structures as long as the liquid inlet port 3a, the oil trap 40, the air discharge port 3b, and the collected liquid discharge port 3c are provided. For example, the oil trap 40 may be formed of a fine porous metal material (such as a crushed aluminum member) or baffles.

[0058] In each of the above-described embodiments, the collected liquid discharge hose 3d is connected to the collected liquid discharge port 3c of the oil separator 3. However, the collected liquid discharge hose 3d may be omitted, and a plug may be provided in the collected liquid discharge port 3c to discharge the collected liquid directly from the collected liquid discharge port 3c.

[0059] Several heaters 49 may also be provided, and heater 49 may also be omitted.

[0060] The oil separator 3 may be a cartridge in which the receiving member 30 is attached to the main body, which includes the housing 11 with a threaded portion. The cover 25 may also be omitted.

[0061] The structure for connecting the liquid inlet port 3a to the hose of the air dryer and the structure for connecting the air outlet port 3b to the air outlet hose 20 may each be other known connecting structures.

[0062] A through hole for discharging air may be formed in the bottom wall of the receiving member 30.

[0063] In each of the above-mentioned embodiments, the outlet 10c of the three-way valve 10 is connected to the liquid inlet port 3a of the oil separator 3, but it may also be connected to the air discharge port 3b. In this case, too, when discharging the collected liquid, air is supplied from the air supply device 6 or the air tank 5 to increase the pressure in the oil separator 3. Therefore, when the oil separator 3 includes the on / off valve 3e as in the second embodiment, the on / off valve 3e is arranged on the side of the liquid inlet port 3a.

[0064] In each of the above-mentioned embodiments, the air supply device 6 of the air tank 5 is connected to the oil separator 3 via the three-way valve 10. However, a gas supply source that supplies a gas other than air, such as nitrogen, may also be connected to the oil separator 3.

[0065] In each of the above embodiments, the directional control valve is a three-way valve, however, any other valve capable of switching the flow direction may also be used. For example, an electromagnetic valve that switches the flow direction by selectively supplying or de-energizing the valve, or a hydraulic valve that switches the flow direction by hydraulic pressure, may be used. These valves are controlled by a controller.

[0066] In each of the above-mentioned embodiments, the oil separator 3 is provided in the exhaust system of the air dryer 2 downstream of the compressor 1 of the air system. However, the oil separator 3 can also be arranged downstream of the compressor 1 of the air system and upstream of the air dryer 2. In this case, oil is separated from the air containing, for example, a lubricant in the compressor 1, and purified air is supplied to the air dryer 2. This prevents the desiccant in the air dryer 2 from being affected by the oil.

[0067] As in Fig. As shown in Figure 9, a collected liquid reservoir tank 60 may be connected to the collected liquid discharge port 3c of the oil separator 3 via the collected liquid discharge hose 3d. The collected liquid reservoir tank 60 stores the collected liquid discharged from the oil separator 3. When the collected liquid reservoir tank 60 is conventionally connected to the oil separator, the collected liquid is discharged from the oil separator into the collected liquid reservoir tank 60 by gravity. In the collected liquid discharging system of each of the above-described embodiments, the collected liquid stored in the collected liquid storage part 48 of the oil separator 3 is discharged by increasing the pressure in the collected liquid storage part 48 by supplying air from the air supply device 6.An introduction port 61 of the collected liquid reservoir tank 60 (or the liquid surface of the collected liquid reservoir tank 60) may be higher in the vertical direction than the collected liquid discharge port 3c of the oil separator 3.

[0068] As in Fig.As shown in Figure 10, the compressed air drying system may include an oil mist separator 70 in addition to the air dryer 2 and the oil separator 3. The oil mist separator 70 includes a filter for capturing oil mist and differs from the air dryer 2 in that it does not contain a desiccant. The oil mist separator 70 is arranged between the compressor 1 and the air dryer 2. The oil mist separator 70 includes an inlet 70a connected to the compressor 1 and an outlet 70b connected to the inlet 2a of the air dryer 2. The outlet 70b discharges air from which oil mist has been removed. The oil mist separator 70 further includes a liquid discharge valve. When the liquid discharge valve is opened, the compressed air is discharged from a liquid discharge port 70c along with the oil captured by the filter.A hose 71 and a branch pipe 72 are connected to the liquid discharge port 70c of the oil mist separator 70. Furthermore, a coupling pipe 74 is connected to the liquid discharge port 2c of the air dryer 2 via a hose 73. The branch pipe 72 is connected to the first inlet 10a of the three-way valve 10 via a hose 75. When the liquid is discharged from the oil mist separator 70 and the air dryer 2, the three-way valve 10 switches the internal flow direction so that fluid flows from the first inlet 10a to the outlet 10c. And when collected liquid from the oil separator 3 is to be discharged, the three-way valve 10 switches the internal flow direction so that air flows from the second inlet 10b to the outlet 10c.

[0069] In addition to the liquid inlet port 3a, the oil separator 3 may include an air introduction port that introduces air into the oil separator 3 to increase the internal pressure of the collected liquid storage part 48. The air introduction part is connected to an air supply source other than the air supply device 6. The air supply source may be the air tank 5. Furthermore, a flow rate control valve may be provided between the air introduction port and the air supply source to regulate the amount of air supplied to the oil separator 3. In this case, the air introduction port and the three-way valve 10 correspond to a mechanism that increases the internal pressure of the reservoir provided in the oil separator 3 and storing the collected liquid.

[0070] The compressor 1 is not necessarily coupled to the combustion engine, but can have a separate kinetic energy source.

[0071] In each of the embodiments described above, the compressed air drying system is mounted on a vehicle with an internal combustion engine, but it may also be mounted on a vehicle with a power source other than an internal combustion engine. Furthermore, the compressed air drying system may also be mounted on machines other than vehicles. LIST OF REFERENCE SYMBOLS

[0072] 1 ... compressor; 2 ... air dryer; 2a ... inlet; 2b ... outlet; 2c ... liquid discharge port; 3 ... oil separator; 3a ... liquid inlet port; 3b ... air discharge port; 3c ... collected liquid discharge port; 3d ... collected liquid discharge hose; 3e ... on / off valve; 4 ... desiccant; 5 ... air tank; 5a ... on / off valve; 5b ... dry air supply passage; 6 ... air supply device; 7 ... air supply passage; 7a ... flow rate control valve; 8 ... liquid discharge passage; 9 ... collected liquid discharge system; 10 ... three-way valve; 10a ... first inlet; 10b ... second inlet; 10c ... outlet; 10d ... coupling passage (pipe); 11 ... housing; 12 ... cover; 18 ... inlet coupling member; 19 ... outlet coupling member; 20 ... air outlet hose; 21 ... baffle; 22 ... first expansion chamber; 23 ... connecting part; 25 ... cover; 26 ... flange; 27 ... screw; 28 ... connecting hole; 29 ... mounting plate; 30 ...Receiving member; 31 ... flange; 32 ... flange; 33 ... second expansion chamber; 34 ... upper wall; 35 ... through hole; 36 ... through hole; 40 ... oil trap; 41 ... impact member; 45 ... retaining washer; 46 ... screw; 47 ... through hole; 48 ... collected liquid storage part; 49 ... heater; 50 ... connecting hole.

Claims

[1] Collected liquid discharge system (9), comprising: an oil separator (3) which separates gas and liquid in an oil-containing fluid to collect oil-containing liquid, and a gas supply source which supplies gas to the oil separator (3), the oil separator (3) comprising: an oil trap (40) which collects liquid; a reservoir that stores the liquid collected by the oil trap (40); a collected liquid discharge port (3c) that discharges the liquid stored in the reservoir; a liquid inlet opening (3a) through which liquid flows; an air discharge opening (3b) which discharges air separated from the fluid; and a three-way valve (10) which increases the internal pressure of the reservoir and which is connected to a line (10d) connected to the liquid inlet port (3a) or the air outlet port (3b), a gas supply passage connected to the gas supply source, and a liquid outlet passage (8) which supplies liquid to the oil separator (3), wherein the three-way valve (10) is configured to switch between a first connection state in which the three-way valve (10) connects the liquid discharge passage (8) to the liquid inlet opening (3a) or the air discharge opening (3b), and a second connection state in which the three-way valve (10) connects the gas supply passage to the liquid inlet opening (3a) or the air discharge opening (3b), wherein in the first connection state, the fluid flowing through the three-way valve (10) flows from the liquid discharge passage (8) to the liquid inlet port (3a) or the air discharge port (3b), and wherein in the second connection state, the fluid flowing through the three-way valve (10) flows from the gas supply passage to the liquid inlet port (3a) or the air outlet port (3b). [2] Collected liquid discharge system (9) according to claim 1, wherein: the oil separator (3) further comprises an on / off valve (3e, 5a) which selectively opens and closes the other of the liquid inlet opening (3a) and the air outlet opening (3b); and the on / off valve (3e, 5a) is closed when the connection state of the three-way valve (10) is in the second connection state. [3] Collected liquid discharge system (9) according to claim 1 or 2, wherein: the liquid inlet opening (3a) is configured to be connected to an air dryer (2) containing a desiccant (4) and drying compressed air, and to separate gas and liquid in a fluid containing oil supplied from the air dryer (2) to collect liquid; and the three-way valve (10) is configured to be connected to an air tank (5) which stores dried compressed air (5b) flowed from the air dryer (2) via the gas supply passage.

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