JPS6044518B2 - oil cooled air compressor - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in oil-cooled air compressors.

As shown in Fig. 1, an oil-cooled compressor, for example, a screw compressor, has a compressor body 1 with built-in male and female rotors, a capacity adjustment valve 2 connected to its suction side, and an oil separator valve 2 connected to its discharge side. An air tank 5 is connected to the discharge side of the oil separator 3 via a pressure holding valve 4. Furthermore, a temperature adjustment valve 7 is connected between the oil separator 3 and the oil cooler 6, and a bypass passage 8 is provided in the temperature adjustment valve 7, so that the bypass passage 8 and the discharge side of the oil cooler 6 are connected to the oil cooler 6. It is connected to the lubricating oil discharge port of the compressor main body 1 via the filter 9 . In this device, the male and female rotors are rotated by the rotation of a transmission machine M that drives the compressor body 1, and air is sucked into the compressor body 1 through a capacity adjustment valve 2, and oil mist, which is oil, is ejected. The oil is sent under pressure and reaches the oil separator 3.

In the oil separator 3, oil mist is separated from compressed air.
Clean compressed air is stored in an air tank 5 via a pressure holding valve 4. Furthermore, the lubricating oil separated by the oil separator 3 is cooled by the oil cooler 6 and returns to the compressor main body 1, where the sealing, lubrication, and cooling of the compressed air between the male and female rotors are repeated. Here, in order to prevent drainage from occurring due to overcooling of the oil cooler 6 and causing accidents such as early deterioration of the oil and rusting of various parts of the compressor, the passage through which the lubricating oil flows is selected by the temperature control valve 7. The oil is then passed through a bypass passage 8 or an oil cooler 6. However, although supercooling in the oil cooler 6 is generally studied in detail, cooling in the oil separator 3 has not been much of an issue.

However, since the oil separator 3 is large compared to other devices, the oil separator 3 may be cooled by the outside air, and drainage may occur in the oil separator 3 itself. Particularly in cold regions, the surface of the oil separator 3 is cooled immediately after startup, and it takes too long for the oil separator 3 to rise to a temperature at which no condensate is generated, resulting in the generation of a large amount of condensate. On the other hand, since the compressor main body 1, electric motor M1 oil separator 3, and air tank 5 occupy a relatively large space structurally, at least when the oil separator 3 and the air tank 5 are arranged separately, the compressor unit The overall size is large, the cost is high, the installation area is large, and the applications are limited.Furthermore, due to the same reason as above, there are many pipings, which increases the cost, and there are also drawbacks such as increased leakage of the air and oil systems.

The present invention solves the above-mentioned problems by incorporating an oil separator in the air tank, which lowers the oil temperature from the heat dissipated from the outer surface of the oil separator, thereby preventing premature oil deterioration due to drainage and rusting of various parts of the compressor. There is also a device characterized by being configured to prevent.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an overall configuration diagram using the configuration of the present invention. To explain this, a capacity adjustment valve 11 is connected to the suction side of the compressor main body 10 which has male and female rotors built in. An oil separator 12 is connected to the discharge side, and the oil separator 12
on the discharge side. is connected to an air tank 14 via a pressure holding valve 13. Here, inside the air tank 14 is an oil separator 1.
2 are stored. One passage formed by the temperature adjustment valve 15, the external heat exchanger 16, the oil filter 17, and the lubricating oil discharge port of the compressor body 10! duct and temperature control valve 1
5. Two lubricating oil passages are constructed, including the bypass passage 18, the oil filter 17, and another passage formed from the lubricating oil discharge port of the compressor body 10, and the lubricating oil is divided into both of these passages. Next, a description will be given of an embodiment in which the configuration of the present invention shown in FIG. 2 is applied to an actual screw compressor.
FIG. 3 is a front sectional view of an air tank and an oil separator. A first stage oil separator 22 is installed in an airtight manner. The first stage oil separator 22 has an oil sump chamber 22
a, and a first discharge pipe 27 that penetrates the top surface of the oil reservoir chamber 22a.
and a second discharge pipe 28 connected to the bottom of the oil reservoir chamber 22a.
The first discharge pipe 27 protrudes from the opening of the air tank 14, and the second discharge pipe 28 penetrates the bottom wall of the air tank 14. Opening 2 of the mirror plate 21
1a is formed with a blind lid 2C in which a groove 24'' is formed so that a flange 23 and holes 23'', 23'' provided in the flange 23 form a passage (an air passage 25 to be described later).
One end of a cylindrical member 24a constituting the second stage oil separator 24 installed in the air tank 14 is fixed to the flange 23, and the other end penetrates the partition wall of the oil storage chamber 22a and is inserted into the same chamber 22a. The side surface of the cylindrical member 24a, which is open to and located within the same chamber 22a, faces the discharge port of the first discharge pipe 27. First stage oil separator 22, second stage oil separator 24
An air passage 25 communicating between the inside of the tank 14 and the inside of the air tank 14 is provided in the flange 23 and the blind lid 24'', and the pressure holding valve 13 is provided in the second stage oil separator 24 at the end of the air passage 25. An oil separation element 26 (filter) is built into the second-stage oil separator 24.As described above, the first-stage oil separator 22 has a discharge port for guiding compressed air from the compressor main body 10. A pipe 27 is connected to the first stage oil separator 2.
2 is separated by an oil separation element 26, and the first stage oil separator 22
A discharge pipe 28 through which lubricating oil stored therein is discharged is connected to the bottom of the first stage oil separator 22. In addition, the discharge pipe 2
A stop valve 20 is attached to 9. Therefore, the compressed air from the discharge pipe 27 is guided into the first stage oil separator 22, and the lubricating oil in the form of oil droplets in the air falls downward, and the lubricating oil in the form of mist is passed through the oil separation element 26. The air not containing lubricating oil is stored in the air tank 14 via the pressure holding valve 13 and the air passage 25.

Then, when the stop valve 30 is opened, it is fed outside the machine. On the other hand, the separated lubricating oil is discharged to the outside of the first stage oil separator 22 through the discharge pipe 28. In this case, air tank 14
Since the compressed air sent therein is at a high temperature, the first stage oil separator 22 and the second stage oil separator 24 are heated, and since the temperature rises quickly, the set temperature is quickly reached.

Therefore, no drainage occurs. Also, even during unloading operation, the compressed air in the air tank 14, that is, the air around the oil separator 12 (22, 24) acts as a heat insulator, so the first stage oil separator 22 and the second stage oil separator The temperature of the container 24 does not drop suddenly.

Although the above embodiments have been explained using a screw compressor as an example, the present invention is not limited to this type of compressor. As described above, the present invention forms an oil separator with a first-stage oil separator and a second-stage oil separator, and furthermore, the side surface of the second-stage oil separator is connected to the opening of the discharge pipe that guides compressed air. Since both oil separators are installed in the air tank so as to face each other, the following effects are produced.

1. Prevents overcooling of oil, prevents drain generation and rusting of various parts of the compressor, and improves reliability.

2. Even when used in cold regions, troubles caused by lens generation are reduced and the range of applications is expanded.

Since an oil separator is housed for three air tanks, the compressor unit can be made smaller.

4. Since the number of piping between the air tank and the oil separator is reduced, leakage defects from air and oil joints are reduced.

5. Considering the above item 4, the cost of the piping section and the number of piping workers are reduced, resulting in a cost reduction.

6. The oil mist in the compressed air is easily turned into oil droplets on the side wall of the first stage oil separator and the side wall of the second stage oil separator,
Therefore, air from which most of the oil has been removed is sent to the oil separation element in the second stage oil separator, so that the separation effect of the oil separation element can be improved and its lifespan can be extended.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional screw compressor, Fig. 2 is an overall block diagram of a screw compressor using the structure of the present invention, and Fig. 3 is a sectional view of a specific embodiment according to the present invention. . 10... Compressor body, 12... Oil separator, 13... Pressure holding valve, 14... Air tank, 22... First stage Oil separator, 24...
Second stage oil separator, 22a...Oil sump chamber, 24a.
...Cylindrical member, 27...First discharge pipe, 2
8...Second discharge pipe.

Claims (1)

[Claims] 1. A compressor body that compresses air while being cooled by oil, an oil separator to which compressed air and oil are supplied from the compressor body, and an oil separator connected to the oil separator via a pressure holding valve. An oil-cooled air compressor comprising: an air tank for storing compressed air from which oil has been removed in a container; An oil separator is provided, and the first stage oil separator is connected to an oil sump chamber fixed inside the air tank and leads compressed air from the compressor main body to the oil sump chamber. A second low discharge pipe is connected to the first discharge pipe and the oil sump chamber and protrudes to the outside through the bottom wall of the air tank for discharging lubricating oil stored at the bottom of the oil sump chamber. The second oil separator includes a cylindrical member having one end fixed to the air tank and the other end penetrating the partition wall of the oil reservoir chamber and opening into the oil reservoir chamber, A side surface of the cylindrical member located in the reservoir chamber faces a discharge port of the discharge pipe of the first discharge pipe, and the cylindrical member further has an air passageway with one end opening into the air tank. An oil-cooled air compressor, characterized in that it communicates with the other end via the pressure holding valve.