JP7579013B1 - Compressed Air Generator - Google Patents

Abstract

[Problem] To provide a compressed air generating device that can prevent a drop in temperature of compressed air and the generation of drainage due to contact with outside air, and can make the most of its performance. [Solution] A compressed air generating device with a built-in compressed air pressure circuit, the compressed air pressure circuit comprising various devices consisting of, at least from the front stage, an oil-lubricated compressor, an oil tank, an air dryer, and an oil removal device, the various devices being housed in a single housing and connected to each other via air piping, and the oil removal device being connected to an outlet that can send air from the housing to the rear stage via air piping. [Selected drawing] Figure 1

Description

The present invention relates to a compressed air generating device in which various devices constituting a compressed air pressure circuit, such as a compressor, an oil tank, an air dryer, and an oil removal device, are casing-packed in a single housing.

Compressed air generated by compressors is used for a variety of purposes, including spray painting and automatic train opening and closing devices. Depending on the purpose of the compressed air, various devices such as air dryers, cyclone separators, and oil removal devices are installed in the middle of the pneumatic circuit before the compressed air is discharged from the compressor.

However, in the conventional compressed air circuit configuration, when the air piping connecting various devices is extended due to the arrangement of the various devices, the area in contact with the outside air increases, the temperature of the compressed air passing through it drops, and the amount of saturated water vapor decreases, which makes it easier for drainage to occur in the air piping. In addition, there is also the problem that the generated drainage flows into the oil removal device used to remove oil from the compressed air, accelerating the deterioration of the removal material filled therein.
Therefore, there was a need for technology that could prevent a drop in the temperature of the compressed air due to the extension of the air piping, while also preventing moisture from entering the oil removal device.

The applicant has developed a technology in which an air dryer and an oil-water separator are integrated, and the compressed air generated by the compressor is dried using the air dryer, and the drain generated is passed through the oil-water separator to purify it and discharge it. This technology is proposed in Patent No. 3368429 (Patent Document 1). In addition, the applicant has developed a technology in which a cyclone separator and an oil adsorption device are installed to separate and remove moisture and oil mist from the compressed air generated by the compressor, and the clean compressed air is sent to the subsequent stage. This technology is proposed in Patent No. 6713596 (Patent Document 2).

However, while the proposal in Patent Document 1 is useful for improving the efficiency of drain treatment by shortening the drain piping from the air dryer to the oil-water separation device, the purpose of the oil-water separation device is to separate and remove the drain discharged from the air dryer, and it does not solve the above-mentioned problem.
Furthermore, according to the proposal in Patent Document 2, although the cyclone separator is useful for separating and removing moisture and foreign matter, the compressed air that is sent out remains at a high temperature, and the temperature difference with the inside of the oil adsorption device causes the temperature of the compressed air to drop, which can result in drainage being generated within the device, so the above-mentioned problems are still not solved.

The applicant focused on the phenomenon of drainage caused by the extension of air piping in conventional compressed air circuits as described above, and came up with the idea of arranging the various devices that make up the compressed air circuit in close proximity to each other. By arranging the compressor, oil tank, air dryer, and oil removal device in a single housing and shortening the air piping, the applicant developed a compressed air generating device that prevents the compressed air from dropping in temperature and drainage caused by contact between the air piping and the outside air and prevents drainage from flowing into the oil removal device by arranging the oil removal device after the air dryer, which led to the proposal of the "compressed air generating device" of the present invention.

Patent No. 3368429 Patent No. 6713596

In view of the above problems, the present invention aims to provide a compressed air generating device that can prevent the temperature drop of compressed air and the generation of drainage due to contact with outside air, and can make the most of its performance.

In order to solve the above problems, the present invention provides a compressed air generating device having a built-in compressed air circuit, the compressed air circuit comprising various devices consisting of, at least from the front stage, an oil-lubricated compressor, an oil tank, an air dryer, and an oil removal device, the various devices being housed in a single housing and connected to each other via air piping, the oil removal device being connected to an outlet capable of sending air from the housing to the rear stage via an air piping , the air piping connecting the air dryer and the oil removal device being bent upward in a region below the oil removal device and connected to the underside of the oil removal device, and a drain piping being connected to the upward bent point of the air piping .

The present invention also employs a means for arranging the various devices and air piping in a generally straight line in a plan view.

Furthermore, the present invention employs a means in which a precooler is provided at a predetermined intermediate location of the air piping that connects the oil tank and the air dryer.

The compressed air generating device of the present invention has various devices housed in a single housing, which shortens the required length of the air piping connecting the various devices and reduces the area of the air piping that comes into contact with the outside air, helping to prevent a drop in the temperature of the compressed air being sent into the air piping.

In addition, with the compressed air generating device of the present invention, various devices and air piping are arranged in a generally straight line in a plan view, which makes it possible to reduce the number of bends in the air piping, thereby reducing the reduction in pressure loss of the compressed air sent into the air piping and suppressing the generation of drainage due to the presence of bends.

Furthermore, with the compressed air generating device according to the present invention, an oil cooler is provided at a predetermined intermediate location in the oil pipe, so that the lubricating oil discharged from the oil-lubricated compressor when the compressed air is generated is separated as oil from the compressed air in the oil tank, and the separated and recovered oil is cooled in the oil cooler before being sent to the compressor and circulated again as lubricating oil for the oil-lubricated air compressor.

1 is an explanatory diagram showing an embodiment of an air compressor according to the present invention. FIG. FIG. 4 is an explanatory diagram showing another embodiment of the air compressor according to the present invention.

The greatest feature of the compressed air generating device 1 of the present invention is that it employs a means for casing the compressor 2, oil tank 21, air dryer 3 and oil removal device 4, which are various devices that constitute the compressed air pressure circuit, into a housing 10.
Hereinafter, an embodiment of a compressed air generating device 1 according to the present invention will be described with reference to the drawings.

The compressed air generating device 1 according to the present invention is not limited to the embodiment described below, but can be modified as appropriate within the scope of the technical concept of the present invention, i.e., within the scope of shapes, dimensions, materials, etc. that can achieve the same functional effects.

1 and 2 are explanatory diagrams showing an embodiment of a compressed air generating device 1 according to the present invention.
The compressed air generating device 1 of the present invention is a device in which a compressor 2, an oil tank 21, an air dryer 3 and an oil removal device 4 (hereinafter sometimes referred to as various equipment) are casing'd in a single housing 10, and the compressed air generated by the compressor 2 is sent to the air dryer 3 after the oil is separated from it in the oil tank 21, and the compressed air which has had water separated and been dried by the air dryer 3 is sent to the oil removal device 4, where it is sent out from the outlet 20 as clean compressed air from which the oil has been removed, and is supplied to downstream compressed air-using equipment.

The various devices are connected to each other by air piping 11 made of hollow tubes, which serve as a flow path for compressed air sent from the compressor 2 to the devices using the compressed air.
Although there is no particular limitation on the diameter of the air pipes 11 connecting the various devices, it is possible to reduce the pressure loss of the compressed air by making the diameters of the respective air pipes 11 the same. In addition, although there is no particular limitation on the length of the air pipes 11, it is possible to enhance the effect of preventing temperature changes in the compressed air sent into the air pipes 11 by shortening the length of the air pipes 11 arranged between the various devices and narrowing the area in contact with the outside air.

The casing of the present invention is a structure in which the various devices that make up the compressed air pressure circuit capable of generating compressed air to be sent to compressed air-using equipment are entirely covered by a housing 10, and which is capable of blocking at least the sides and top from the outside world.
There are no particular limitations on the casing method, and possible methods include completely covering the various devices in their entirety with a metal box, or constructing the entire sides of the various devices out of glass or reinforced plastic, etc., so that some or all of the various devices can be visually observed.
1, the housing 10 is provided with an air pipe 11d that sends the compressed air that has passed through various devices to the outside of the housing 10, and an air outlet 20 that can be connected to a downstream device that uses compressed air. In addition, although not shown, an air intake port that allows the compressor 2 to take in outside air, an air vent used for temperature control inside the housing 10, and the like are provided as necessary.
There is no particular limitation on the locations where the various devices are arranged, and for example, they may be arranged in a substantially straight line in a plan view. By adopting such an arrangement, it is possible to reduce the number of bends in the air piping 11 that occur when the various devices are connected to each other, and it is possible to reduce pressure loss and drainage caused by collisions of compressed air at the bends.

The oil-lubricated compressor 2 is a device that compresses air and raises its pressure to a predetermined pressure (for example, 0.7 MPa) to generate compressed air.
There are various types of oil-lubricated compressors 2, such as reciprocating, rotary, and centrifugal types, depending on the structure for generating compressed air. There is no particular limitation on the type of oil-lubricated compressor 2 used in the present invention, and any type and structure can be used. In addition, an air pipe 11a is connected to the oil-lubricated compressor 2 to send the generated compressed air to the oil tank 21.
When the oil-lubricated compressor 2 is in operation, the compressed air contains a large amount of the lubricating oil used in the oil-lubricated compressor 2, so an oil tank 21 is provided downstream to remove the oil from the compressed air.

The oil tank 21 separates and removes oil contained in the compressed air before it flows into the air dryer 3.
The oil tank 21 removes oil contained in the compressed air generated by the oil-lubricated compressor by separating it using the filter function of an oil element, etc. The oil tank 21 makes it possible to reduce the amount of oil contained in the drain generated in the downstream air dryer 3 in advance, and further reduces the amount of oil in the compressed air passing through the downstream oil removal device 4, which makes it possible to extend the life of the oil removal performance by preventing the oil from adhering to the filler in the oil removal device.
The oil tank 21 is connected to an air pipe 11a through which the compressed air generated by the oil-lubricated compressor 2 is supplied, and an air pipe 11b through which the compressed air from which the oil has been separated and removed is supplied to the air dryer 3.
There are no particular limitations on the shape and internal structure of the oil tank 21, and it is sufficient to use a conventionally known structure that separates and removes oil from the compressed air flowing in through the air pipe 11a and further allows the removed oil to be stored inside the oil tank 21. For example, as shown in Fig. 1, a cylindrical pipe having a hollow portion and closed at the top and bottom is used as the oil tank 21, and the air pipe 11a extending from the oil-lubricated compressor 2 is inserted from the side wall side of the oil tank 21 into the hollow portion while penetrating it, and the discharge port 15 at the tip of the air pipe 11a is bent upward, so that the compressed air containing oil is released toward the top of the oil tank 21, and the compressed air from which the oil has been separated by passing through an oil element 22 provided at the top of the oil tank 21 flows into the air pipe 11b connected to the air dryer 3.

The oil tank 21 may be provided with an oil element 22 that separates and removes oil from the compressed air. The material and shape of the oil element 22 used in this embodiment are not particularly limited as long as they are capable of separating oil from the compressed air. Conventional known elements such as filter paper made of cellulose or synthetic fibers woven into a bellows shape may be used. The structure of the oil element 22 is also not particularly limited. For example, the top surface of the oil element 22 may be connected to the connection between the oil tank 21 and the air pipe 11b, and the bottom surface may be closed. The side surface may be configured as an oil filter, so that the compressed air that flows into the oil tank 21 always passes through the oil filter before flowing into the air pipe 11b, and the oil in the compressed air may be separated.

The oil separated and removed from the compressed air by the oil element 22 and the like, and the drainage generated in the oil tank 21 are stored near the bottom of the oil tank 21. At this time, the oil and the drainage are stored in a state separated vertically, that is, the oil is stored in the upper part and the drainage is stored in the lower part. It is preferable that the oil stored in the oil tank 21 is returned to the oil-lubricated compressor 2 and reused as lubricating oil (as shown in the figure), and a lubricating oil circulation structure is constructed between the oil-lubricated compressor 2 and the oil tank 21, which contributes to saving and effective use of the lubricating oil. Specifically, the oil tank 21 and the oil-lubricated compressor 2 are connected by an oil pipe 13, and the oil stored in the oil tank 21 is sent to the oil-lubricated compressor 2 through the oil pipe 13. At this time, an oil cooler 23 for cooling the sent oil is arranged at a predetermined intermediate position of the oil pipe 13. Since the compressed air generated by the oil-lubricated compressor 2 is at a high temperature, the oil contained in the compressed air is also at a high temperature, and therefore the oil separated and removed in the oil tank 21 is also stored at a high temperature. If such oil is sent to the oil-lubricated compressor 2 while still at a high temperature, it is expected that its function as a lubricant will decrease and even malfunctions of the oil-lubricated compressor 2 will occur. Therefore, it is desirable to cool the oil to its initial temperature as a lubricant before sending it. For this reason, an oil cooler 23 is provided at a predetermined intermediate position of the oil pipe 13.
Although not shown, it is also preferable to provide a dust filter or the like in the oil pipe 13 before or after the oil cooler 23 to remove foreign matter such as dust remaining in the oil.

Drain pipe 7 and drain trap 5 are provided near the bottom of oil tank 21 to discharge drainage stored together with oil. Drainage, which is water, is heavier than oil, so as described above, it is stored in oil tank 21 separated into oil at the top and drainage at the bottom. Therefore, drainage pipe 7 is connected near the bottom of oil tank 21. When drainage is discharged, an oil trap with a float or the like for detecting the amount of oil built in drain trap 5 can also be used to prevent the oil stored in oil tank 21 from being discharged to the outside together with the drainage.

The air dryer 3 is a device for drying the compressed air sent from the oil tank 21 via the air pipe 11b, and removing moisture.
The air dryer 3 may be of a refrigeration type, a hollow fiber membrane type, an adsorption type, etc., depending on the method of removing moisture. The air dryer 3 used in the present invention may be of any of the refrigeration type, hollow fiber membrane type, and adsorption type, and is not particularly limited, but the most commonly used is the refrigeration type air dryer 3. The refrigeration type air dryer is a device that uses the latent heat of evaporation of a refrigerant to cool compressed air and condense and remove the contained moisture, and is preferable because it can be introduced relatively inexpensively.
The air dryer 3 is connected to an air pipe 11b through which compressed air from which oil has been separated and removed in the oil tank 21 is sent, and an air pipe 11c through which the dried compressed air from which moisture has been removed is sent to the oil removal device 4.
Furthermore, in the process of condensing and removing moisture contained in the compressed air, the refrigeration type air dryer generates drain inside the air dryer 3 due to a decrease in the amount of saturated water vapor caused by cooling, so a drain pipe 7 is provided to discharge the drain, and the drain that flows into the drain pipe 7 is discharged to the outside by a drain trap 5. It is sufficient to use a conventionally known drain trap 5, and there are electromagnetic types, float types, and the like depending on the discharge method, but there is no particular limitation.

As shown in FIG. 2, a preferred embodiment is one in which a precooler 8 is disposed at a predetermined intermediate location of the air pipe 11b connecting the oil tank 21 and the air dryer 3. The precooler 8 is disposed at an intermediate location of the air pipe 11b connecting the oil tank 21 and the air dryer 3, and is a device for precooling the compressed air flowing into the air dryer 3. The specific structure of the precooler 8 is not particularly limited as long as it can remove preheating, and it is sufficient to use existing equipment such as an air-cooled aftercooler. By disposing such a precooler 8, the compressed air flows into the air dryer 3 in a precooled state, making it possible to improve the performance of the air dryer 3.

The oil removal device 4 is a device for bringing the dried compressed air sent from the air dryer 3 via the air piping 11c into contact with fillers provided within the oil removal device 4, separating and removing the oil contained in the compressed air, and sending the air to the subsequent stage as clean compressed air.
There are no particular limitations on the shape or performance of the oil removal device 4, and it is sufficient to use a conventionally known device that has a shape and performance capable of supplying clean compressed air to a compressed air-using device connected downstream, taking into account the oil that may be generated during the air compression process and in various equipment.
Similarly, there are no limitations on the filler to be placed in the oil removal device 4, and conventionally known materials such as, for example, cubic or rectangular shaped polyethylene, polypropylene, polyethylene terephthalate, amines coated or impregnated into nonwoven fabric, zeolite, which is a porous mineral, activated carbon, etc., can be used to achieve the above-mentioned performance.
The oil removal device 4 is connected to an air pipe 11c through which the dried compressed air having had moisture removed by the air dryer 3 is supplied, and an air pipe 11d through which the clean compressed air from which the oil has been separated and removed is supplied to compressed air-using equipment via an air outlet 20.

1, a preferred embodiment is one in which the drain pipe 7 and the drain trap 5 are provided at a predetermined intermediate position of the air pipe 11c connecting the air dryer 3 and the oil removal device 4. By adopting such an embodiment, it is possible to prevent drain (drain generated by collision with the bent inner wall of the air pipe 11c) that may be generated on the way from the air dryer 3 to the oil removal device 4 from flowing into the oil removal device 4. Regarding the connection point between the air pipe 11c and the drain pipe 7 , in consideration of the position where drain generation is expected and the final prevention of drain flow into the oil removal device 4, a preferred embodiment is one in which the connection is made to the upward bent position, which is the final bent position of the air pipe 11c, and by adopting such an embodiment, the effect of preventing drain flow into the oil removal device 4 is maximized.

It is also preferable to arrange the air dryer 3 and the oil removal device 4 close to each other and shorten the distance of the air pipe 11c connecting them. By shortening the distance, it is possible to minimize the cooling effect when the compressed air passes through the air pipe 11C and suppress the generation of drainage. This makes it possible to omit the installation of the drain pipe 7 and drain trap 5 on the air pipe 11C while still preventing drainage from flowing into the oil removal device 4.

A preferred embodiment is one in which a valve 6 capable of adjusting the amount of air sent is provided near the air outlet 20 of the air piping 11d. By adopting such an embodiment, it becomes easy to determine whether compressed air is to be sent to the compressed air-using equipment and to adjust the flow rate, and it is also possible to shut off the flow path during maintenance of the compressed air-using equipment and various other equipment or when an abnormality occurs.
Similarly, it is also preferable to provide a valve 6 capable of adjusting the flow rate at a predetermined central location in the drain piping 7 before the drain trap 5, which makes it easy to adjust the flow rate of the drain and block the flow path.

The main operations and functions of the compressed air generating device 1 consisting of the above components will be described with reference to FIG.
The compressed air generating device 1 comprises an oil-lubricated compressor 2, an oil tank 21, an air dryer 3, and an oil removal device 4 arranged via air piping 11a-d, and an oil cooler 23 arranged in the middle of an oil pipe 13 connecting the oil-lubricated compressor 2 and the oil tank 21, with the entire device being housed in a housing 10.
First, compressed air is generated in the oil-lubricated compressor 2, sent through the air piping 11a, and flows into the oil tank 21 from the discharge port 15. The compressed air at this time contains the lubricating oil used in the oil-lubricated compressor 2 as oil mist. The compressed air that has flowed into the oil tank 21 has oil (oil mist) separated and removed by the oil element 22 provided in the oil tank 21, and flows into the air dryer 3 through the air piping 11b. The compressed air that has been dried by the air dryer 3 flows into the oil removal device 4 through the air piping 11c. The clean compressed air from which the oil has been removed by the oil removal device 4 is sent from the air outlet 20 through the air piping 11d to the compressed air-using equipment.
The oil separated from the compressed air in the oil tank 21 flows from the bottom of the oil tank 21 into the oil cooler 23 via the oil pipe 13. The oil cooled in the oil cooler 23 and lowered in temperature is supplied to the oil-lubricated compressor 2 via the oil pipe 13, and is reused as lubricating oil.

The above describes the basic configuration and operation/action of the compressed air generating device 1 according to the present invention, but the present invention is not limited to the configuration shown in the above embodiment and drawings. For example, by arranging the air dryer 3 and oil removal device 4 adjacent to each other inside the housing 10, it is possible to further shorten the length of the air pipe 11c connecting them, preventing a decrease in the temperature and saturated water vapor amount of the compressed air that may occur by passing through the air pipe 11c, and also preventing performance degradation of the oil removal material due to moisture adhesion inside the oil removal device 4.

As described above, the compressed air generating device 1 of the present invention casings the oil-lubricated compressor 2, oil tank 21, air dryer 3, and oil removal device 4 in a single housing 10, thereby shortening the distance of the air piping 11 connecting the devices and realizing space saving for the entire device, and also reducing the temperature change caused by contact of the air piping 11 with the outside air, thereby suppressing the generation of drainage, and further preventing performance degradation of the oil removal device 4 due to moisture adhesion, thereby enabling a longer lifespan.

The present invention can be used as a space-saving compressed air generating device with excellent oil removal performance in any field that requires oil-free compressed air, such as food processing, electronic component and car body painting. Therefore, it is believed that the "compressed air generating device" of the present invention has great industrial applicability.

REFERENCE SIGNS LIST 1 Compressed air generating device 2 Oil-lubricated compressor 3 Air dryer 4 Oil removal device 5 Drain trap 6 Valve 7 Drain pipe 8 Precooler 10 Housing 11 Air pipe 11a Air pipe 11b Air pipe 11c Air pipe 11d Air pipe 13 Oil pipe 15 Discharge port 16 Oil tank trap 20 Outlet 21 Oil tank 22 Oil element 23 Oil cooler

Claims (3)

A compressed air generating device having a built-in compressed air pressure circuit,
The compressed air circuit includes various devices including, in order from the front, an oil-lubricated compressor, an oil tank, an air dryer, and an oil removal device.
The various devices are housed in a single housing and connected to each other via air piping, and the oil removal device is connected to an air outlet capable of sending air from the housing to a downstream stage via air piping .
A compressed air generating device characterized in that an air piping connecting an air dryer and an oil removal device is bent upward in a lower area of the oil removal device and connected to the underside of the oil removal device, and a drain piping is connected to the upward bent part of the air piping .
The compressed air generating device according to claim 1, characterized in that the various devices and air piping are arranged in a substantially straight line in a plan view. 3. The compressed air generating device according to claim 1, further comprising a precooler disposed at a predetermined intermediate position of an air pipe connecting the oil tank and the air dryer.