JPS6245107Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an automatic drain discharge device for an oil-cooled compressor.

Generally, oil-cooled compressors are known in which a large amount of oil is injected into the casing to remove heat generated during compression, and the gaps between the rotor teeth and between the rotor and the casing are sealed with oil. In this one, the first
As shown in the figure, the air sucked through the air filter 1 and entered the compression section 2 passes through the discharge check valve 3 and the pipe 4 together with the injected oil and enters the oil separator 5, where the oil accumulates at the bottom of the oil separator 5 and is compressed. Air passes through a pressure holding valve 6 and a check valve 7 connected to the oil separator 5, and then is sent out from the discharge port 8, and the oil collected at the bottom of the oil separator 5 is sucked into the compressor through a pipe 9 and a throttle 9a. Drain that has been returned to the side and accumulated at the bottom of the oil separator 5 is manually discharged from a drain valve 10 provided at the bottom of the oil separator 5 at an appropriate time.

By the way, in such an oil-cooled compressor, compressed air comes into contact with oil, so moisture in this compressed air becomes drain (water) and is generated in the oil and accumulates at the bottom of the oil separator 5. The stored oil emulsifies,
Since oil containing moisture is sent to the compression section 2, rust may occur in various parts of the compressor, making it impossible to operate the compressor. For this reason, as described above, the drain valve 10 is opened manually to discharge the drain from the drain valve 10, but this is time-consuming and wasteful as it also causes oil to be discharged.
There were also disadvantages such as forgetting to drain the drain.

Therefore, as shown in FIG. 2, a drain tank 12 is further connected to the lower part of the oil separator 5 via a communication pipe 11, and when the oil and drain in the oil separator 5 flow into this drain tank 12, their specific gravity When the drain naturally separates due to the difference and the drain enters the lower side of the oil, the float 14 rises along the guide shaft 13, and when the magnet 16 provided on the float 14 reaches near the contact point of the reed switch 15, the reed switch 15 An automatic drain discharge device has been proposed in which a contact is turned on, energizes the solenoid valve 17, opens the solenoid valve 17, and drains drain from the solenoid valve 17.

However, in this case, if a failure occurs and the solenoid valve 17 provided on the drain discharge side of the drain tank 12 is left open, the communication pipe 1 between the oil separator 5 and the drain tank 12
Since no opening/closing valve is provided in the valve 1, there is a risk that the oil in the oil separator 5 may be discharged from the solenoid valve 17 via the drain tank 12.

This idea was made in view of the above circumstances,
The reed switch is turned ON and OFF by the vertical movement of a float having a magnet in the drain tank connected to the oil separator, and each of the reed switches installed in the drain tank so as to be able to communicate with each other through the inflow and outflow passages of the drain tank is turned on and off. By controlling the on-off valves to open and close in an inverse relationship to each other and by providing a gas chamber located above the inflow passage in the drain tank, when the on-off valve interposed in the outflow passage is open, the gas chamber interposed in the inflow passage is closed. The on-off valve is closed to prevent oil from flowing out in the oil separator, and the gas pressure in the gas chamber can push out the drain in the drain tank. It is an object of the present invention to provide an automatic drain discharge device for an oil-cooled compressor that can automatically and quickly discharge condensate mixed therein.

An embodiment of this invention will be described below with reference to FIGS. 3 and 4. 21 in FIGS. 2 and 3 is a base frame, and this base frame 21 has a drain tank 22.
is installed. This drain tank 22 includes a container 23, is provided at the center of the bottom of the container 23, has a flange 24 at the top, and has a reed switch 25 provided at the upper part of the inside.
The guide shaft 2 has a lead wire led out to the outside in an airtight manner.
6 and is fitted to this guide shaft 26 so as to be vertically movable,
A float 29 has a specific gravity between that of water and oil, has a magnet 27 buried close to the guide shaft 26, has legs 28 at the bottom, and has a gas chamber 30 at the center, and is airtightly attached to the container 23. It consists of a lid body 31 that is detachably attached. Note that, when the float 29 reaches the lowest position, the leg portions 28 of the float 29 are loosely fitted into the base portion 32 of the guide shaft 26 to a predetermined depth to provide a slight gap between the base portion 32 and the float 29. This serves to make it easier for the float 29 to float.

The drain tank 22 has a gas chamber 30 in the lid 31.
An inflow passage 33 is provided below the top of the container 23, and an outflow passage 3 is provided below the top of the container 23.
4 are provided. A solenoid valve (on-off valve) 35 is connected to the inflow passage 33, and a solenoid valve (on-off valve) 36 is connected to the outflow passage 34. Solenoid valve 3
5 is a strainer 37, a stop valve 38, a joint 39,
It is connected to the bottom of an oil separator (not shown) via a pipe or the like, so that it can communicate with the interior of the oil separator. A pipe for discharging drain to a predetermined location is connected to the solenoid valve 36 via a connection port 40 . The solenoid valves 35 and 36 are reed switches 25
energization or de-energization is achieved via the relay 41 by turning the contacts ON or OFF.As a result, when the solenoid valve 35 located in the inflow passage 33 is open, the solenoid valve 36 located in the outflow passage 34 is closed. When the solenoid valve 36 opens, the solenoid valve 35 closes, so that the solenoid valves 36 and 35 are opened and closed in an inverse relationship to each other.

The lid body 31 also includes an oil return port 42 to the compressor.
However, the opening on the drain tank 22 side is always opened below the oil level in the drain tank 22 when the compressor is in operation. An oil return pipe (not shown) is connected to this oil return port 42 via a joint 43, and this oil return pipe is connected to the suction side of the compressor via a throttle (not shown). There is. Note that this oil return pipe is not limited to the suction side of the compressor, and may be connected to other parts of the compressor as long as the pressure is lower than the internal pressure of the drain tank 22.

When the compressor is operated with the stop valve 38 open, the float 29 is at the lowest position, the reed switch 25 is in the OFF state, the solenoid valve 35 is in the open state, and the solenoid valve 36 is in the OFF state. In the closed state, a predetermined amount of oil flows from the oil separator into the drain tank 22 via the joint 39, the stop valve 38, the strainer 37, the solenoid valve 35, and the inflow passage 33, and the air in the drain tank 22 is compressed. It is sealed in a gas chamber 30. When condensate occurs in the oil separator, this condensate is
It flows into the drain tank 22 through the joint 39, strainer 37, stop valve 38, solenoid valve 35, and inflow passage 33, and is naturally separated due to the difference in specific gravity between this drain and the oil in the drain tank 22, and enters under the oil. . As a result, when the float 29 rises and the magnet 27 reaches a position a predetermined distance below the contact point of the reed switch 25, the contact point of the reed switch 25 turns ON, and the solenoid valve 35 is energized via the relay 41. 36 is in a de-energized state, and the solenoid valve 35
is in a closed state, and the solenoid valve 36 is in an open state. Then, the drain and oil from the oil separator are prevented from flowing into the drain tank 22, and the drain in the drain tank 22 is pushed downward through the oil by the gas pressure in the gas chamber 30, and the drain passage 34, It passes through the electromagnetic valve 36, the connection port 40, and a pipe (not shown) connected to the connection port 40, and is discharged to a predetermined location in a very short time.

When the drain in the drain tank 22 decreases, the float 29 begins to descend, and when the magnet 27 falls a predetermined distance from the contact of the reed switch 25, this contact is instantly turned OFF, the power to the solenoid valve 35 is cut off, and the solenoid valve 36 is turned off. is energized, the solenoid valve 35 is opened, and the solenoid valve 36 is closed. As a result, drain is prevented from being discharged from the drain tank 22, and drain and oil are allowed to flow from the oil separator into the drain tank 22, and this operation is repeated thereafter. Therefore, according to this embodiment, the solenoid valve 35 interposed in the inflow passage 33 and the outflow passage 3
4 can be controlled to open and close in an inverse relationship to each other, so that only the condensate mixed in this oil can be used to increase the gas pressure in the gas chamber 30 without discharging the oil injected into the compressor. This allows for rapid discharge.

In addition, the drain tank 22 is connected to the oil separator.
The oil that has flowed into the interior and separated from the drain is sent to the oil return port 42.
The oil is then returned to the air suction side of the compressor or the low-pressure part of the compressor, which has a pressure lower than the internal pressure of the drain tank 22, via the joint 43, the oil return pipe, and the throttle. Even if the oil is constantly returned to the air suction side etc. during operation, this returned oil is throttled by the throttle interposed in the oil return pipe and returned with a limited flow rate. The gas pressure in the gas chamber 30 to be discharged hardly decreases.

Further, if the solenoid valve 35 and the solenoid valve 36 are provided on the same side of the drain tank 22 as shown in FIGS. 3 and 4, the device becomes compact and economical.

As explained above, according to this invention, the reed switch is turned ON and OFF by vertical movement of the float having a magnet in the drain tank connected to the oil separator, and the reed switch is turned on and off through the inflow passage and outflow passage of the drain tank. Since the on-off valves provided in the drain tank so as to be able to communicate with each other are controlled to open and close in an inverse relationship to each other, and the drain tank is provided with a gas chamber located above the inflow passage, the on-off valves are alternately opened and closed. The opening and closing can be controlled in an inverse relationship to each other, and as a result, only the drain can be automatically discharged without discharging the oil injected into the compressor. Since the condensate mixed in the oil injected into the compressor can be expelled automatically, quickly, and in a stable operating state, despite the simple structure.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram for explaining the function of the oil separator of a conventional oil-fed compressor, Fig. 2 is a schematic sectional view of an automatic drain discharge device of a conventional oil-fed compressor, and Fig. 3 is a schematic diagram of the oil separator of a conventional oil-fed compressor. A plan view showing an embodiment of the invention,
FIG. 4 is a partially cutaway sectional view thereof. 22... Drain tank, 25... Reed switch, 26... Guide shaft, 27... Magnet, 29... Float, 30... Gas chamber, 35, 36... Solenoid valve (on/off valve).

Claims (1)

[Scope of utility model registration request] A drain tank, a guide shaft provided in the drain tank and containing a reed switch, a float fitted to the guide shaft so as to be movable up and down and having a specific gravity between oil and water and having a magnet, and in the drain tank. an outflow passage provided to communicate with the lower part; an inflow passage provided above the outflow passage and communicated with the drain tank; and a reed switch interposed between each of the passages,
An on-off valve that is controlled to open and close in an inverse relationship when turned off;
An automatic drain discharge device for an oil-cooled compressor, comprising a gas chamber located above the inflow passage within the drain tank.