JP7222643B2 - Structure of drain processing part of oil-refrigerated compressor - Google Patents

Description

The present invention relates to the structure of the drain processing section of an oil-cooled compressor. The present invention relates to an oil-refrigerated compressor characterized by a structure for processing drainage generated by an oil mist filter.

In an oil-cooled compressor that compresses gas to be compressed together with lubricating oil for cooling, lubrication and sealing, as shown in FIG. In addition to a driving source 112 such as an engine or a motor, a receiver tank 113 for storing compressed gas discharged from the compressor main body 111 is provided.

The receiver tank 113 is provided with an oil separator 113a, and the compressed gas discharged from the compressor main body 111 as a gas-liquid mixed fluid with lubricating oil is introduced into the receiver tank 113 to separate the lubricating oil and the compressed air. In addition to the primary separation, the compressed air after the primary separation is further passed through the oil separator 113a to remove the lubricating oil remaining in the mist state in the compressed air. It is configured so that it can be supplied to a consumption side connected to a compressed air consuming device such as a gas generator that generates gas using compressed air as a raw material.

The lubricating oil collected in the receiver tank 113 is again introduced into the compressor body 111 through an oil supply passage 130 having an oil cooler 131 and an oil filter 132 to lubricate and cool the compressor body 111. A lubricating oil circulation system is formed between the compressor main body 111 and the receiver tank 113 .

In the oil-refrigerated compressor 100 configured as described above, although the receiver tank 113 and the oil separator 113a remove oil from the compressed air, the compressed air that has passed through them still contains water and oil. included.

Therefore, when a device that requires the supply of dry compressed air or oil-free compressed air is connected to the consumer side that receives compressed air from the oil-cooled compressor 100, the receiver tank 113 A device such as a dryer 123 and an oil mist filter 124 is provided in the supply flow path 120 from air to the consumption side to remove moisture and oil from the compressed air before it is introduced to the consumption side.

Here, the dryer 123 cools the introduced compressed air, condenses and removes moisture in the compressed air, heats and dries the moisture-free compressed air, and sends it to the consumer side. , and the moisture generated by condensation during cooling is discharged as drain.

In addition, the oil mist filter 124 collects the oil present in the state of fine particles (mist) in the compressed air by allowing the compressed air to pass through a filter (filter material) having fine pores. After that, the lubricating oil dripping and accumulated in the drain reservoir is drained.

Since these drains all contain oil such as lubricating oil, if they are discharged as they are together with household wastewater, they cause environmental pollution.

Therefore, a drain processing unit that introduces the drain from the dryer and separates it into water and oil is installed in the drain processing unit of the compressor provided with the dryer 123 described above, and the oil contained in the drain is removed in this drain processing unit. There has been proposed a device in which only clean water can be discharged out of the machine after cleaning (see FIGS. 3 and 4 of Patent Document 1).

In addition, in the compressor drain processing unit equipped with the oil mist filter 124 together with the dryer 123, not only the drain generated by the dryer described above but also the drain generated by the oil mist filter is introduced into the drain processing device and processed. (see FIG. 1 of Patent Document 2).

Japanese Patent No. 4382955 JP-A-2003-336581

Among the configurations described above as the prior art, the compressor described in Patent Document 1 includes a description of a dryer 123 and a drain processing device that processes the drain generated by this dryer, but oil mist There is no description of the provision of the filter 124, and therefore no disclosure or suggestion regarding the treatment of the drain generated in the oil mist filter 124.

On the other hand, the oil-cooled compressor introduced as Patent Document 2 is equipped with an oil mist filter 124 in addition to the dryer 123, and not only the drainage generated by the dryer 123 but also the drainage generated by the oil mist filter 124 Since a structure is adopted in which the oil is introduced into the drain processing device and treated, the drain generated in the oil mist filter 124 is prevented from becoming a cause of contamination or the like.

However, if not only the drain generated by the dryer 123 but also the drain generated by the oil mist filter 124 is introduced into the drain processing device and processed, the amount of drain, especially the amount of oil content, to be processed by the drain processing device. Therefore, it is necessary to adopt a drain processing device with a high processing capacity, which increases the price of the oil-cooled compressor.

In addition, consumables such as filters used to absorb oil in the drain treatment equipment will no longer absorb oil after a predetermined amount of oil has been absorbed, and must be replaced. Since the time for replacing these consumables is also shortened, the time for maintenance of the drain processing device is shortened and the running cost increases.

As described above, the lubricating oil that is primarily separated by the receiver tank 113 and collected by the oil separator 113a provided in the receiver tank 113 accumulates at the bottom of the receiver tank 113 and flows through the oil supply passage 130 to the compressor again. Lubricating oil is supplied to the main body 111 and circulates in the lubricating oil circulation system described above. Since the lubricating oil is collected outside the circulating system, the amount of lubricating oil circulating in the lubricating oil circulating system gradually decreases as the drain is discharged. Since seizure of 111 may also occur, it is necessary to periodically replenish the reduced amount of lubricating oil.

Furthermore, when a plurality of oil mist filters 124 are provided for the purpose of improving oil separation performance, etc., a drain pipe for each oil mist filter 124, an on-off valve that opens and closes this drain pipe, and a backflow of drain to the oil mist filter are prevented. If a check valve or the like is provided, the number of these parts and the accompanying increase in assembly man-hours increase the cost of the product.

Therefore, when a plurality of oil mist filters are provided, it is desirable to have a structure in which the above-described check valves and on-off valves are shared among the oil mist filters so that the number of parts can be reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the drawbacks of the above-mentioned prior art. It is possible to make it difficult for the lubricating oil to decrease from the dryer, and in the configuration equipped with a drain processing device that processes the drain generated in the dryer, the size of the drain processing device can be reduced by reducing the amount of drain introduced into the drain processing device. It is another object of the present invention to provide an oil-cooled compressor having a drain processing section that can reduce the frequency of replacement of consumables such as an oil separation filter used in the drain processing device.

Further, in addition to the above objects, the present invention uses a single on-off valve or check valve as a common configuration for the plurality of oil mist filters even when a plurality of oil mist filters are provided. It is an object of the present invention to provide an oil-cooled compressor equipped with a drain processing section capable of reducing the number of parts and reducing the manufacturing cost by adopting a circuit configuration capable of reducing the number of components.

Means for solving the problems are described below together with the symbols used in the mode for carrying out the invention. This code is for clarifying the correspondence between the description of the claims and the description of the mode for carrying out the invention, and needless to say, it is used restrictively to interpret the technical scope of the present invention. It is not something that can be done.

In order to achieve the above object, the oil-cooled compressor 1 of the present invention is
An oil-cooled compressor body 11 that sucks the gas to be compressed, compresses it together with lubricating oil, and discharges the compressed gas as a gas-liquid mixed fluid with the lubricating oil, and the compressed gas discharged by the compressor body 11. A receiver tank 13 that introduces and separates gas and liquid, a supply channel 20 that supplies the compressed gas from which the lubricating oil is separated in the receiver tank 13 to the consumption side, and the lubricating oil separated in the receiver tank 13. In the oil-cooled compressor 1 provided with the oil supply passage 30 for re-supplying to the compressor main body 11,
The receiver tank 13 is provided with an oil separator 13a for further removing the oil content in the compressed gas from which the lubricating oil has been primarily separated in the receiver tank 13, and the supply passage 20 has a function as a check valve. provided with a pressure regulating valve 21,
Oil mist filters 24 and 25 are installed in the supply passage 20 on the secondary side of the pressure regulating valve 21 to collect oil contained in the compressed gas flowing through the supply passage 20 and discharge it as drain. A drain pipe 50 provided separately from the separator 13a and communicating with the oil mist filters 24 and 25 communicates with the suction space of the compressor main body 11 (claim 1).

In the present invention, the "suction space" of the compressor body 11 refers to a space formed in the compressor body 11 and connected to the suction port. This is the space before entering the meshing space of the rotor.

In addition, "communication" with the suction space means direct communication with the suction space, as well as a suction flow path 16 (suction flow path 16 also includes a case where communication is provided via another member such as a passage in the intake control valve 17 existing in the intake passage 16 .

A dehumidifier such as an aftercooler 22 or a dryer 23 for dehumidifying the compressed gas passing through the supply flow path 20 is provided in the supply flow path 20 on the primary side of the oil mist filters 24 and 25. It is preferable that a drain processing device 45 for discharging the drain after removing the oil content in the drain is provided in communication with the drain pipe 40 of the dehumidifier (Claim 2).

A plurality of the oil mist filters 24, 25 are provided in series in the supply passage 20, and the drain pipes 50 of the oil mist filters 24, 25 are connected to branch pipes 51, 52 communicating with the oil mist filters 24, 25, respectively. , one end 53a of which communicates with all of the branch pipes 51 and 52, and the other end 53b of which is composed of a collecting pipe 53 communicating with the suction space of the compressor main body 11,
The branch pipes 51 and 52 communicating with the oil mist filters 24 and 25 are connected from the upstream oil mist filter (first oil mist filter 24) to the downstream oil mist filter (second oil mist filter 25). ) are provided with means such as throttles 56 and 57 and check valves for preventing the inflow of drain and compressed gas through the branch pipes 51 and 52,
The collection pipe 53 is provided with an on-off valve 54 for opening and closing the collection pipe 53, and a check valve 55 for preventing reverse flow of lubricating oil and compressed gas from the compressor main body 11 side to the oil mist filter 24, 25 side. (Claim 3).

Due to the configuration of the present invention described above, the oil-refrigerated compressor 1 having the drain processing section structure of the present invention has the following remarkable effects.

By connecting the drain pipe 50 of the oil mist filters 24, 25 provided in the supply passage 20 to the suction space, the oil-refrigerated compressor 1 can be operated without discharging the drain generated in the oil mist filters 24, 25 to the outside of the machine. The oil mist filters 24 and 25 can be kept inside the oil mist filters 24 and 25, and the environmental pollution caused by discharging the oil mist filters 24 and 25 to the outside of the machine can be effectively prevented.

Further, since the drain generated by the oil mist filters 24 and 25 is introduced into the compressor main body 11, there is no need to provide a separate processing device for processing this drain.

Moreover, the drain generated in the oil mist filters 24 and 25 is mainly composed of lubricating oil, and this drain is introduced into the compressor main body 11 and formed between the compressor main body 11 and the receiver tank 13. By returning the lubricating oil to the circulating system, it was possible to slow down the rate of decrease of the lubricating oil from the circulating system and reduce the frequency of replenishing the lubricating oil.

Moreover, the suction space has a negative pressure when the compressor body is driven, and since the pressure is lower than that of the oil mist filters 24 and 25, the drain generated by the oil mist filters 24 and 25 is removed by the suction caused by this negative pressure. It could be collected smoothly by aspiration.

A dehumidifier such as an aftercooler 22 or a dryer 23 for dehumidifying the compressed gas flowing through the supply channel 20 is provided in the supply channel 20 on the primary side of the oil mist filters 24 and 25, and the drain generated by the dehumidifier is provided. In the configuration in which the drain processing device 45 for removing the oil content inside and discharging it as clean water is provided in communication with the drain pipe 40 of the dehumidifier, the compressed gas after the moisture is removed and dried is filtered through the oil mist filter. 24, 25, the amount of water contained in the drain collected by the oil mist filters 24, 25 can be reduced, and the drain with a higher proportion of lubricating oil can be introduced into the compressor main body 11. was made.

Also, the drain generated by the dehumidifiers such as the aftercooler 22 and the dryer 23 can be discharged outside the machine as clean water after the oil is removed by the drain processor. , 25, but only for the treatment of the drainage generated in the dehumidifier. In addition, the frequency of replacement of consumables in the drain processing device 45, such as an oil adsorption filter, is reduced, thereby reducing running costs.

In the configuration in which a plurality of the oil mist filters 24 and 25 are provided, the branch pipes 51 and 52 communicating with the oil mist filters 24 and 25, respectively, and the collecting pipe in which the branch pipes 51 and 52 are assembled into one A drain pipe 50 of the oil mist filters 24 and 25 is constituted by 53, and the collection pipe 53 is communicated with the suction space of the compressor main body 11, and the branch pipes 51 and 52 are connected to the branch pipes 51 and 52, respectively. By providing throttles 56 and 57 and check valves to prevent drain or compressed gas from being introduced from the oil mist filter 24 on the upstream side to the oil mist filter 25 on the downstream side, Drainage can be recovered only by providing an on-off valve 54 for opening and closing the collecting pipe 53 and a check valve 55 for preventing reverse flow from the compressor main body 11 side to the oil mist filter 24, 25 side. The number of parts can be reduced compared to the configuration in which an on-off valve 54' and a check valve 55' are provided for each of the pipes 51 and 52 (see FIG. 3). We were able to reduce the manufacturing cost of the machine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an oil-cooled compressor of the present invention; (A) is an enlarged explanatory view of the oil mist filter portion of FIG. 1, and (B) is an explanatory view of a problem when an orifice (throttle) is removed from the configuration of (A). Explanatory drawing which shows the modification of the drain process part for oil mist filters. Explanatory drawing of the conventional oil-cooled compressor.

An oil-cooled compressor having a drain processing structure according to the present invention will be described below with reference to the accompanying drawings.

[Overall configuration of oil-cooled compressor]
The oil-cooled compressor 1 to which the drain processing section structure of the present invention is applied has an air filter 15 and an intake control valve 17 extending from the secondary side of the air filter 15 to the compressor main body 11 as shown in FIG. A compressor main body 11 such as a screw compressor that compresses and discharges the compressed gas sucked through the suction passage 16, which is air in this embodiment, together with the lubricating oil injected into the cylinder, and this compressor In addition to a drive source (motor in this embodiment) 12 for driving the main body 11, a receiver tank 13 is provided which communicates with the discharge port 11a of the compressor main body 11 through a discharge passage 14. The compressed air discharged from the compressor main body 11 as a gas-liquid mixed fluid with the lubricating oil can be introduced into the .

The intake control valve 17 described above controls the intake air to the compressor body 11 by opening and closing in accordance with the change in the pressure on the secondary side of the compressor body 11, which is the pressure in the receiver tank 13 in this embodiment, so that the intake air is kept substantially constant. The receiver tank 13 is configured to supply pressurized compressed air to the consuming side, and the receiver tank 13 receives the compressed air discharged from the compressor body 11 as a gas-liquid mixed fluid with lubricating oil. The compressed air and the lubricating oil are primarily separated into the compressed air and the lubricating oil, and the compressed air after the primary separation of the lubricating oil can be supplied to the consumption side.

The compressed air from which the lubricating oil has been primarily separated in the receiver tank 13 is further removed by the oil separator 13a provided in the receiver tank 13, and the oil remaining in the mist state in the compressed air is further removed. A consumer device that consumes compressed air by separating specific components (such as nitrogen and oxygen) contained in the supplied compressed air in this embodiment to generate product gas (nitrogen gas, oxygen gas, etc.) A PSA (Pressure Swing Adsorption) type gas generator is supplied to the connected consumer side.

On the other hand, the lubricating oil separated from the compressed air in the receiver tank 13 and recovered in the receiver tank 13 passes through the oil supply passage 30 provided with the oil cooler 31 and the oil filter 32, and is again supplied to the compressor body 11 through the oil supply port. 11b, from the compressor main body 11 to the receiver tank 13 via the discharge pipe 14, and from the receiver tank 13 to the compressor main body 11 via the oil supply passage 30. A lubricating oil circulation system is formed.

A pressure regulating valve 21 having a function as a check valve is provided in the supply passage 20 from the receiver tank 13 to the consumption side, and the pressure in the receiver tank 13 is equal to or higher than the operation start pressure of the pressure regulating valve 21. The pressure regulating valve 21 prevents backflow of compressed air from the consumption side to the receiver tank 13 side.

Also, in the supply passage 20 on the secondary side of the pressure regulating valve 21, there are dehumidifiers 22 and 23 for dehumidifying the compressed air discharged from the compressor main body 11, and Oil mist filters 24, 25 for removing oil from the compressed air, and an activated carbon filter 26 for introducing the compressed air after passing through the oil mist filters 24, 25 and adsorbing organic gases and odors in the compressed air. is supplied from the supply channel 20 to the consumption side to which the gas generator is connected.

In this embodiment, as the dehumidifier, the aftercooler 22 cools the high-temperature compressed air discharged from the compressor body 11, and the compressed air after passing through the aftercooler 22 is further cooled to condense moisture in the compressed air. A dryer 23 is provided to heat and dry the compressed air from which moisture has been removed.

In this embodiment, the drain generated by condensation during cooling by the aftercooler 22 is introduced into the dryer 23 together with the compressed air, and the drain trap provided in the dryer 23 together with the drain generated during cooling in the dryer 23 (Fig. (not shown)), etc., and both the aftercooler 22 and the dryer 23 constitute the above-mentioned "dehumidifier" that dehumidifies the compressed air. Either the aftercooler 22 or the dryer 23 may be provided. In this case, the aftercooler 22 or the dryer 23 provided in the supply flow path 20 serves as the above-mentioned "dehumidifier". .

[Structure of drain processing part]
(1) Treatment of drain generated in aftercooler and dryer It is collected by a trap (not shown) and introduced into a drain treatment device 45 through a drain pipe 40 connected at one end to the drain trap, where the oil contained in the drain is removed. Clean water (drain water) is discharged out of the machine after it has been cleaned.

Drain water discharged to the outside of the machine through the drain treatment device 45 is once introduced into the monitoring tank 46, and after visually confirming that it has been treated in a clean state, It is preferably configured to discharge to

A stop valve 41 for opening and closing the drain pipe 40 is provided in the above-described drain pipe 40 for the dryer, which communicates the dryer 23 and the drain processing device 45, and a strainer 43 and a An electromagnetic switching valve 44 is provided.

By configuring the drain pipe 40 for the dryer in this way, when the electromagnetic on-off valve 44 is opened with the stop valve 41 open, the drain accumulated in the drain trap of the dryer 23 is compressed in the supply channel 20. Pushed by air pressure, the water is sent to the drain processing device 45 through the drain pipe 40, and the clean water from which oil is removed by the drain processing device 45 can be discharged out of the apparatus.

In the illustrated embodiment, the drain generated in the aftercooler 22 is also collected in the dryer 23, but the aftercooler 22 is also provided with a drain trap for collecting the drain generated in the aftercooler 22. A drain pipe having the same structure as the above-described drain pipe 40 for the dryer, which communicates between the trap and the drain processing device 45, may be provided separately.

However, the adoption of the illustrated configuration in which the drain generated in the aftercooler 22 is also collected in the dryer 23 can reduce the number of drain pipes, stop valves, electromagnetic on-off valves, strainers, and other constituent devices. It is preferable in that it can be done.

(2) Treatment of drain generated by oil mist filter It is constructed so that the drain, which is composed of oil, can be introduced into the suction space of the compressor main body 11 via the drain pipe 50 .

This "suction space" is a space formed in the compressor main body 11 and connected to the suction port. The space before entering is this "intake space".

It should be noted that the introduction of the drain into the suction space is performed directly to the suction space by providing a communication hole communicating with the suction space in the casing of the compressor main body 11 and connecting the drain pipe 50 to the communication hole. Alternatively, the drain pipe 50 may be connected to any position of the suction flow path 16 to introduce the gas through another member such as the suction flow path 16 .

In addition, since the suction flow path 16 on the secondary side of the intake control valve 17 and the suction space described above are always at negative pressure during operation of the compressor (when the compressor body 11 is driven), In order to more reliably collect the drain of the oil mist filters 24 and 25 to the compressor main body 11, the drain pipe 50 preferably communicates with the intake passage 16 on the secondary side of the intake control valve 17 and the intake space. .

A single oil mist filter may be provided in the supply flow path 20, but a plurality of oil mist filters may be arranged in series to remove oil in the compressed air in multiple stages. In this embodiment, as an example, a first oil mist filter 24 having a filtration degree (particle diameter to be collected) of 0.3 μm and a second oil mist filter 25 having a filtration degree of 0.01 μm are connected in series. Communicating, the first oil mist filter 24 collects lubricating oil with a relatively large mist diameter, and the second oil mist filter 25 collects lubricating oil with a small mist diameter, thereby of oil can be removed efficiently.

At the bottom of the first and second oil mist filters 24, 25, as shown in FIG. 2A, drain reservoirs 24a, 25a are formed in which the lubricating oil collected by the filter (filter material) drips and accumulates. By connecting the drain outlets 24b and 25b provided at the lower ends of the drain reservoirs 24a and 25a to the suction passage 16 and the suction space formed in the compressor main body 11 via the drain pipe 50, , the oil mist filters 24 and 25, the drain mainly composed of the lubricating oil is discharged through the compressor main body 11 into the lubricating oil circulation system formed between the compressor main body 11 and the receiver tank 13. It is configured so that it can be returned to

In this embodiment, the oil mist filters 24, 25 and the compressor main body are arranged so that the drain from the plurality of oil mist filters 24, 25 can be introduced into the suction space of the compressor main body 11. 11, the branch pipes 51 and 52 communicated with the drain outlets 24b and 25b of the oil mist filters 24 and 25, respectively, and one end 53a of the drain pipe 50 communicates with both of the branch pipes 51 and 52. The other end 53b (see FIG. 1) of the collection pipe 53 is communicated with the suction port of the compressor body 11 so that the oil mist filters 24 and 25 collect the oil mist. It is constructed so that the discharged drain can be introduced directly into the suction space of the compressor main body 11 .

In the drain pipe 50 of the oil mist filters 24, 25, as shown in FIG. , the opening and closing of the branch pipes 51 and 52 may be individually controlled. However, in this embodiment, as shown in FIGS. The electromagnetic on-off valve 54 and the check valve 55 are provided only in the first oil mist filter 24 and the check valve 55, and the electromagnetic on-off valve 54 and the check valve 55 are provided as a common configuration for both the first oil mist filter 24 and the second oil mist filter 25. 3, the number of solenoid on-off valves 54 and check valves 55 used is reduced.

Here, as shown in FIG. 3, in the configuration in which check valves 55' and 55' and electromagnetic on-off valves 54' and 54' are provided in the respective branch pipes 51 and 52, the first oil mist filter 24 is connected. Drainage or compressed air is prevented from flowing from the branch pipe 51 connected to the second oil mist filter 25 to the branch pipe 52 communicating with the second oil mist filter 25 .

However, as shown in FIG. 2(B), the drain outlet 24b of the first oil mist filter 24 and the drain outlet 25b of the second oil mist filter 25 are not provided with check valves or electromagnetic switching valves. The branch pipes 51 and 52 are communicated with each other, and the branch pipes 51 and 52 are communicated with the suction port of the compressor main body 11 via the collecting pipe 53. is provided, the drain outlet 24b of the first oil mist filter 24 and the drain outlet 25b of the second oil mist filter 25 are communicated through the branch pipes 51 and 52. becomes.

Here, since the compressed air flowing in the supply flow path 20 causes a pressure drop every time it passes through the first oil mist filter 24 and the second oil mist filter 25, the pressure in the first oil mist filter 24 is On the other hand, since the pressure in the second oil mist filter 25 is low, in the configuration shown in FIG. Separately from the normal flow of compressed air introduced from the oil mist filter 24 to the second oil mist filter 25, the first oil mist filter 24 flows to the second oil mist filter 25 via the branch pipes 51 and 52. A stream of compressed air is introduced.

As a result, along with the flow of this compressed air, the drain accumulated in the drain reservoir 24a of the first oil mist filter 24 flows into the second oil mist filter 25 via the drain outlet 25b, and flows into the second oil mist filter 25. Together with the drain accumulated in the drain reservoir 25a of the oil mist filter 25, the oil is mixed with the compressed air flowing in the supply passage 20, and the oil is mixed again in the compressed air supplied to the consumption side.

Therefore, in the configuration of the present embodiment in which the electromagnetic on-off valve 54 and the check valve 55 are provided only in the collection pipe 53, as shown in FIGS. 56, 57 are provided, and the branch pipes 51, 52 are joined on the secondary side of the orifices 56, 57, so that the first oil mist filter 24 is sent to the second oil mist filter via the branch pipes 51, 52. 25 is prevented from inflow of drain or compressed air.

In the illustrated embodiment, the orifices 56 and 57 are provided in the branch pipes 51 and 52, respectively. If it can be prevented, the inflow of drain or compressed air may be similarly prevented by adjusting the pipe diameters of the branch pipes 51 and 52 to narrow the flow passage area. Not limited.

Also, although illustration is omitted, instead of the configuration shown in FIG. By configuring in this way, when the electromagnetic on-off valve 54 is closed, the branch pipe 51 connected to the first oil mist filter 24 is connected to the second oil mist filter 25. It may be constructed so as to reliably block the inflow of compressed air and drain into the pipe 52 and prevent re-mixing of oil into the compressed air supplied to the consumer side.

In addition, reference numeral 26 in FIG. 1 denotes an activated carbon filter containing activated carbon as a filter medium, which removes impurities such as organic gas and odors that could not be removed by the aftercooler 22, the dryer 23, and the oil mist filters 24 and 25. do.

[Action, etc.]
In the oil-cooled compressor 1 described above, when the compressor main body 11 is driven by a drive source 12 such as a motor, the suction space of the compressor main body 11 includes an air filter 15, a suction flow path 16, and an intake control valve 17. The air introduced in this way is introduced into the meshing space of the screw rotor and then compressed together with the lubricating oil injected into the cylinder through the oil supply port 11b. Compressed air is discharged as a gas-liquid mixed fluid.

The compressed air thus discharged from the compressor body 11 as a gas-liquid mixed fluid with lubricating oil is introduced into the receiver tank 13, where it is primarily separated into compressed air and lubricating oil.

When the pressure of the compressed air introduced into the receiver tank 13 rises above a predetermined pressure set by the pressure regulating valve 21, the pressure regulating valve 21 opens and the compressed air in the receiver tank 13 is released into the receiver tank 13. After the lubricating oil remaining in the mist state in the compressed air is removed by passing through an oil separator 13a provided in the air, the lubricating oil is supplied to the consumption side through the supply passage 20. As shown in FIG.

Compressed air introduced from the receiver tank 13 through the oil separator 13a into the supply passage 20 is cooled by the aftercooler 22 and then introduced into the dryer 23 for further cooling. After the drain is collected and removed by a drain trap (not shown) provided in the dryer 23, it is heated in the dryer 23 and introduced into the consumption side as dried compressed air.

The electromagnetic on-off valve 44 provided in the drain pipe 40 communicating with the drain trap of the dryer 23 keeps the drain pipe 40 closed when the oil-cooled compressor 1 is stopped. During operation, the drain pipe 40 is intermittently opened for a predetermined time (several seconds) at predetermined time intervals (several tens of seconds). is pushed out by the pressure of the compressed air in the supply flow path 20 and introduced into the drain treatment device 45 through the drain pipe 40. After the oil content in the drain is separated in the drain treatment device 45, it functions as clean water. discharged outside.

The time interval at which the electromagnetic on-off valve 44 is opened is determined based on the calculated amount of drain generated based on the ambient temperature.

On the other hand, when the compressed air dried by the dryer 23 passes through the first oil mist filter 24 and the second oil mist filter 25, the oil contained in the compressed air is collected by the filter (filter material). , the lubricating oil collected by the filters drips into drain reservoirs 24a, 25a provided at the bottoms of the first and second oil mist filters 24, 25 and is collected.

The compressed air from which moisture and oil have been removed in this way is passed through the activated carbon filter 26 as necessary to further remove organic gases and odors from the compressed air. etc. are introduced into the connected consumers.

An electromagnetic on-off valve 54 for opening and closing a collecting pipe 53 provided in a drain pipe 50 communicating between the drain outlets 24b, 25b of the oil mist filters 24, 25 and the suction port of the compressor main body 11 is used for the oil-cooled compressor. 1 is kept closed when the compressor 1 is stopped, while the collecting pipe 53 is intermittently opened for a predetermined time (several seconds) at predetermined time intervals (several tens of minutes) when the oil-cooled compressor 1 is in operation. to discharge the drain (oil).

The amount of drain generated in the oil mist filters 24 and 25 is extremely small compared to the amount of drain generated in the dryer 23 described above. The frequency with which the electromagnetic on-off valve 54 opens is reduced.

As a result of intermittent opening of the collecting pipe 53 by the electromagnetic on-off valve 54 in this way, when the electromagnetic on-off valve 54 is opened, the drain collected in the oil mist filters 24 and 25 is discharged into the suction space of the compressor main body 11. , is introduced into the meshing space of the screw rotor together with the air introduced into the suction space through the suction passage 16, and lubricates the compressor body together with lubricating oil injected into the cylinder through the oil supply port 11b. , used for cooling and sealing.

As described above, the branch pipes 51 and 52 communicating with the respective oil mist filters 24 and 25 are provided with orifices 56 and 57. The drain port 25b of the second oil mist filter 25 is configured so that no drain or compressed air flows in. As shown in FIG. Compared to the configuration in which the check valves 55' are provided separately, the drain generated in both the oil mist filters 24 and 25 can be smoothly collected with a small number of parts.

Since the drain collected by each of the oil mist filters 24 and 25 is mainly composed of lubricating oil, it must be returned to the lubricating oil circulation system through the suction space of the compressor main body 11. Therefore, it is possible to make it difficult to reduce the amount of lubricating oil in the lubricating oil circulation system.

In addition, by adopting a configuration in which the drain generated by the oil mist filters 24 and 25 is returned to the circulation system of the lubricating oil through the suction space of the compressor main body 11 without being discharged to the outside of the machine, There is no need to purify the drain generated by the oil mist filters 24 and 25, and compared with the case where the drain generated by the oil mist filters 24 and 25 is introduced into the drain processing device 45 described above for processing, As a result of reducing the amount of drain treated by the drain treatment device 45, the size of the drain treatment device 45 can be reduced, and the manufacturing cost of the oil-refrigerated compressor 1 can be reduced. Running costs can be kept low by extending the life of consumables such as filters.

Reference Signs List 1 oil-cooled compressor 11 compressor body 11a discharge port 11b oil supply port 12 drive source (motor)
REFERENCE SIGNS LIST 13 receiver tank 13a oil separator 14 discharge channel 15 air filter 16 intake channel 17 intake control valve 20 supply channel 21 pressure control valve (check valve)
22 After cooler (dehumidifier)
23 dryer (dehumidifier)
24 oil mist filter (first)
24a drain reservoir 24b drain outlet 25 oil mist filter (second)
25a drain reservoir 25b drain outlet 26 activated carbon filter 30 oil supply channel 31 oil cooler 32 oil filter 40 drain pipe (for dryer)
41 Stop valve 43 Strainer 44 Electromagnetic on-off valve 45 Drain processing device 46 Monitoring tank 50 Drain pipe (for oil mist filter)
51, 52 branch pipe 53 collecting pipe 53a one end (of collecting pipe)
53b other end (collecting pipe)
54, 54' electromagnetic on-off valve 55, 55' check valve 56, 57 orifice (restriction)
REFERENCE SIGNS LIST 100 oil-cooled compressor 111 compressor body 112 drive source 113 receiver tank 113a oil separator 120 supply channel 121 check valve 123 dryer 124 oil mist filter 130 oil supply channel 131 oil cooler 132 oil filter

Claims (3)

An oil-cooled compressor body that draws in the compressed gas, compresses it together with the lubricating oil, and discharges the compressed gas as a gas-liquid mixed fluid with the lubricating oil, and introduces the compressed gas discharged from the compressor body. a receiver tank for gas-liquid separation, a supply passage for supplying the compressed gas from which the lubricating oil has been separated in the receiver tank to the consumption side, and the lubricating oil separated in the receiver tank and returned to the compressor body. In an oil-cooled compressor equipped with an oil supply passage,
The receiver tank is provided with an oil separator for further removing the oil content in the compressed gas from which the lubricating oil has been primarily separated in the receiver tank, and the supply passage is provided with a pressure adjustment function as a check valve. provide a valve,
In addition to the oil separator, an oil mist filter is provided in the supply passage on the secondary side of the pressure regulating valve to collect oil contained in the compressed gas flowing in the supply passage and discharge it as a drain. 1. A drain processing section structure for an oil-cooled compressor, characterized in that a drain pipe communicating with said oil mist filter communicates with a suction space of said compressor body. A dehumidifier is provided in the supply passage on the primary side of the oil mist filter to dehumidify the compressed gas passing through the supply passage, and the drain is removed after removing the oil content in the drain generated by the dehumidifier. 2. A drain processing section structure for an oil-cooled compressor according to claim 1, wherein a drain processing device for discharging is provided in communication with a drain pipe of said dehumidifier. A plurality of the oil mist filters are provided in series in the supply flow path, and the drain pipe of the oil mist filter is connected to a branch pipe communicating with each oil mist filter, and communicated at one end with all of the branch pipes, The other end side is composed of a collecting pipe communicating with the suction space of the compressor main body,
Each of the branch pipes communicating with the oil mist filters is provided with means for preventing drain and compressed gas from flowing from the upstream oil mist filter to the downstream oil mist filter via the branch pipe,
3. The oil according to claim 1, wherein the collecting pipe is provided with an on-off valve for opening and closing the collecting pipe, and a check valve for preventing reverse flow from the compressor main body side to the oil mist filter side. The structure of the drain processing part of a cold compressor.

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