JP2005083219A - Air compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air compressor with reduced a installation space, and noise, and increased flow rate of compressed air supplied to the outside of the compressor. <P>SOLUTION: The air compressor 1 comprises: an oil-cooled compressor main body 11 compressing air while oil is poured; an oil separator/collector 14 disposed to a discharge flow passage 13 extending from the oil-cooled compressor main body, and separating the oil from the compressed air discharged from the compressor main body 11 to collect the oil; an air cooling part 15 cooling the compressed air sent from the oil separator/collector; a dehumidifying part 16 separating out drainage water from the compressed air; and an oil cooler 21 disposed to an oil flow passage 22 to return the collected oil to the oil-cooled compressor main body 11 so as to pour the oil into the oil-cooled compressor main body. Cooling medium in the air cooling part 15 is only the compressed air passing through the dehumidifying part 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air compressor provided with a dehumidifying unit that removes moisture contained in compressed air.

  Conventionally, the air compressor provided with the dehumidification part which removes the water | moisture content contained in compressed air is well-known (for example, refer patent document 1 and 2).

  Patent Document 1 discloses a packaged air compressor. The packaged air compressor includes an oil-cooled screw compressor body, an oil separator / collector, an air-cooled aftercooler, and a dryer in the package. And an air-cooled oil cooler. This dryer is specifically shown in Patent Document 2, and includes a precooler and a dehumidifying unit that removes moisture contained in the compressed air. And this precooler forms the air cooling part with the said aftercooler. The oil separator / collector, the aftercooler, the precooler, and the dehumidifying unit are provided in a discharge passage extending from a screw compressor body, and the compressed air that has passed through the dehumidifying unit is compressed air that is directed to the dehumidifying unit. In the opposite direction to the flow of the air, after passing through the precooler again, it is supplied to equipment using compressed air outside the machine. Further, the oil cooler is interposed in an oil passage extending from the oil separator / collector to the oil injection portion of the screw compressor body.

  In the air compressor, the compressed air needs to be cooled to 10 ° C., which is the dew point, in order to deposit and separate drain water in the dehumidifying section. For this reason, the high-temperature compressed air (approximately 80 ° C.) discharged from the screw compressor main body, passing through the oil separator / recoverer, and oil-removed is heated to the atmosphere via the cooling air from the fan by the aftercooler. And then cooled to a predetermined temperature (about 50 ° C.), and further cooled to a predetermined temperature (about 40 ° C.) by compressed air (10 ° C.) passing through the dehumidifying section and flowing into the pre-cooler by the pre-cooler. Is done. On the other hand, the compressed air that has passed through the dehumidifying part and has flowed into the precooler is heated by the amount of heat obtained from the compressed air toward the dehumidifying part (about 20 ° C.), and there is no fear of water droplets being generated. It is supplied to equipment using compressed air outside the machine.

On the other hand, the oil separated and recovered from the compressed air by the oil separator / collector is cooled by the cooling air from the fan in the oil cooler of the oil flow path, led to the oil injection section, and repeatedly circulated. .
JP-A-8-247075 Japanese Patent Laid-Open No. 10-30568

  In the case of the conventional air compressor described above, the air cooling section is composed of the aftercooler and the precooler, and the aftercooler is an air-cooled type with a fan, and in this aftercooler, an oil separation and recovery device is provided. The compressed air is cooled by releasing the heat of the compressed air that has passed through to the atmosphere. The oil cooler is also an air-cooled type with a fan.

On the other hand, if the performance of the air compressor is the same, the installation space is desired to be smaller, and if the compressor body of the air compressor is the same, the volume flow rate of the compressed air supplied to the outside of the air compressor is more It is often desirable to be large. However, in the case of the above-described air compressor, there is a problem that the space occupied by the air-cooled aftercooler and the oil cooler is large, which is an obstacle to reducing the installation space. The aftercooler and the oil cooler fan are also noise sources. Further, in order to increase the volume flow rate, the compressed air passing through the precooler through the dehumidifying unit may be heated to a level that does not impede practical use. Since the temperature of the compressed air is considerably decreased, the temperature of the compressed air sent out by the heat exchange in the precooler cannot be raised, that is, the volume flow rate cannot be increased. is there.
An object of the present invention is to provide an air compressor that can reduce the installation space, reduce noise, and increase the volumetric flow rate of compressed air supplied to the outside of the machine. Is.

  In order to solve the above problems, the present invention is provided with an oil-cooled compressor main body that compresses air under oil injection, and a discharge passage that extends from the oil-cooled compressor main body. An oil separation / recovery device that separates and recovers oil accompanying the compressed air discharged from the main body, an air cooling unit that cools the compressed air sent from the oil separation / recovery device, and a refrigerant that circulates continuously. The compressed air cooled by the air cooling unit in the evaporation process in the refrigeration circuit is cooled to the dew point, and a dehumidifying unit for precipitating drain water from the compressed air, and the recovered oil is used as the oil injection for the oil injection. In the air compressor provided with an oil cooler interposed in the oil flow path for returning to the main body of the compressor, the cooling medium in the air cooling unit is only compressed air that has passed through the dehumidifying unit.

  Furthermore, in the present invention, in addition to the above configuration, the cooling medium in the oil cooler is a refrigerant in the evaporation process.

  According to the present invention, the air cooling unit does not release the heat of the compressed air to the atmosphere by the cooling air from the fan, but all the heat obtained by the heat exchange from the compressor air that has passed through the oil separation and recovery unit. It is configured to transmit to the compressed air supplied to the outside of the machine, so an aftercooler with a fan is unnecessary, and it is possible to reduce the installation space and noise, and from the oil separator and collector As a result of guiding the compressed air to the air cooling section, the temperature of the compressed air supplied to the outside of the machine is increased, and the volume flow rate can be increased.

  Furthermore, according to the present invention, there is no need for an air cooling fan for the oil cooling section, and there is an effect that the installation space can be further reduced and noise can be reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an air compressor 1 according to a first embodiment of the present invention, and this air compressor 1 includes an oil-cooled compressor body 11, for example, an oil-cooled screw compressor body. A suction flow path 12 is connected to one side of the oil-cooled compressor main body 11, and a discharge flow path 13 is connected to the other. The discharge flow path 13 includes an oil separation / recovery unit 14, an air cooling unit 15, After passing through the dehumidifying part 16 and again through the air cooling part 15, it extends outside the machine. The oil separator / collector 14 has an oil separation element 17 in the upper part and an oil reservoir 18 at the lower part. The oil cooler 21 is cooled by a fan 19 from the oil reservoir 18 through an oil cooler 21. An oil passage 22 extending to the oil injection portion of the compressor body 11 extends.

  The air sucked into the oil-cooled compressor main body 11 from the suction flow path 12 is compressed under oil injection from the oil flow path 22, and compressed air with oil (eg, about 80 ° C.) is separated into oil. It is discharged toward the collector 14. The compressed air that has flowed into the oil separation / recovery unit 14 with oil passes through the oil separation element 17, is separated from the oil, and is sent out to the portion of the discharge flow path 13 that extends from the upper part of the oil separation / recovery unit 14. The oil thus collected is collected in the oil reservoir 18.

  Compressed air (eg, about 80 ° C.) exiting the oil separator / collector 14 flows into the air cooling unit 15 and is cooled to a predetermined temperature (eg, about 40 ° C.) by exchanging heat as described later. To the dehumidifying section 16. The dehumidifying section 16 is provided in a refrigeration circuit 27 that continuously circulates refrigerant together with a refrigerant compressor 23, an air-cooled condenser 25 cooled by a fan 24, and a capillary tube 26 that is a kind of throttle means. It functions as a vessel. The compressed air that has flowed into the dehumidifying unit 16 is cooled to the dew point (10 ° C.) in the evaporation process in the refrigeration circuit 27. As a result, the moisture contained in the compressed air is precipitated as drain water. To be separated. The drain water is discharged out of the machine through a drain water flow path 29 provided with an on-off valve 28, and the compressed air (10 ° C.) that has been dried and dried is led to the air cooling unit 15 again.

  High-temperature compressed air (for example, about 80 ° C.) that has been discharged from the oil-cooled compressor body 11 and passed through the oil separator / collector 14 without being cooled flows into the air cooling unit 15, The compressed air and the compressed air from the dehumidifying unit 16 exchange heat while flowing in opposite directions so as to form a counterflow. The compressed air from the dehumidifying unit 16 is heated by this heat exchange (eg, about 50 ° C.) and supplied to equipment using compressed air outside the apparatus.

As described above, in the air compressor 1, the high-temperature compressed air (eg, about 80 ° C.) discharged from the air compressor 1 is cooled to the predetermined temperature (eg, about 40 ° C.) on the primary side of the dehumidifying unit 16. In addition, only the heat exchange between the high-temperature compressed air and the compressed air from the dehumidifying unit 16 is performed without using the conventional aftercooler that releases heat to the atmosphere. Then, the temperature of the compressed air sent out of the machine is slightly increased to a practically acceptable level, and the volumetric flow rate of the compressed air is increased. That is, the substantial supply amount of compressed air is increased. In other words, if heat is released to the atmosphere using the conventional aftercooler, there is no heat source for raising the compressed air from the dehumidifying unit 16 to the slightly higher temperature described above, and the compression is sent out of the machine. The air temperature must be as low as about 20 ° C.
In addition, since the air cooler 1 does not use the aftercooler with a fan, the installation space can be reduced, and the fan is not necessary, and noise can be reduced.

FIG. 2 shows an air compressor 2 according to the second embodiment of the present invention, and parts common to the air compressor 1 shown in FIG.
In this air compressor 2, an oil cooler 31 is employed instead of the oil cooler 21 cooled by the fan 19, and this oil cooler 31 is incorporated in the refrigeration circuit 27 and exits the capillary tube 26. The refrigerant in is used as a cooling medium.
With such a configuration, the fan 19 is unnecessary, and the installation space can be further reduced and noise can be reduced.

  By the way, when the air compressor 2 is accommodated in a package to form a package-type air compressor, in FIG. 2, a two-dot chain frame I for accommodating the oil-cooled compressor body 11 and the oil separator / collector 14 is shown. The space portion indicated by the two-dot chain line frame II that accommodates the portion of the refrigeration circuit 27 including the air cooling portion 15 and the dehumidifying portion 16 can be completely partitioned from the oil-cooled compressor main body 11. The generated noise is confined in the package, and the noise reduction becomes easy.

In the air compressor 2 shown in FIG. 2, the oil cooler 31 is provided between the capillary tube 26 and the dehumidifying unit 16, but instead, between the dehumidifying unit 16 and the refrigerant compressor 23. An oil cooler 31 may be provided in the oil cooler 31, and the refrigerant may be in the evaporation process at the oil cooler 31.
Further, an expansion valve may be used in place of the capillary tube 26.

  The air compressors 1 and 2 according to the present invention are applied to, for example, various manufacturing factories, medical and dental treatment instruments, and cleaning devices.

It is a figure showing the whole air compressor composition concerning a 1st embodiment of the present invention. It is a figure which shows the whole structure of the air compressor which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Air compressor 11 Oil-cooled compressor main body 12 Suction flow path 13 Discharge flow path 14 Oil separation recovery device 15 Air cooling part 16 Dehumidification part 17 Oil separation element 18 Oil reservoir part 19 Fan 21 Oil cooler 22 Oil flow Passage 23 Refrigerant compressor 24 Fan 25 Condenser 26 Capillary tube 27 Refrigeration circuit 28 On-off valve 29 Drain water flow path 31 Oil cooler

Claims (2)

An oil-cooled compressor body that compresses air under oil injection;
An oil separation / recovery unit that is interposed in a discharge passage extending from the oil-cooled compressor body, separates and recovers the oil accompanying the compressed air discharged from the oil-cooled compressor body;
An air cooling section for cooling the compressed air sent out from the oil separation and recovery device;
A dehumidifying unit that cools the compressed air cooled by the air cooling unit in the evaporation process in the refrigeration circuit that continuously circulates the refrigerant to its dew point, and deposits drain water from the compressed air;
In an air compressor comprising an oil cooler interposed in an oil flow path for returning the recovered oil to the oil-cooled compressor body for oil injection,
An air compressor characterized in that the cooling medium in the air cooling unit is only compressed air that has passed through the dehumidifying unit. The air compressor according to claim 1, wherein a cooling medium in the oil cooler is a refrigerant in the evaporation process.

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