JPH07122438B2 - Compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor provided with a discharge passage for discharging gas in a discharge passage to the outside of the discharge passage.

[0002]

2. Description of the Related Art Conventionally, a compressor body, a suction filter provided in a suction passage on the suction side of the compressor body, and an intake adjustment for narrowing the suction passage as the discharge pressure becomes higher than a set value. Valve, pressure-holding valve provided in the discharge flow path extending to the discharge side of the compressor body, branching from the discharge flow path upstream of the check valve and opening and closing when the compressor body stops A compressor provided with a valve and a pressure-relief valve through the opening / closing valve, and a discharge passage configured to release the compressed gas in the discharge passage upstream of the check valve into the atmosphere, for example, a screw compression Machines are known. Then, the suction filter removes foreign matter from the suction gas, and the suction control valve regulates the suction gas amount of the compressor body to prevent an abnormal rise in the discharge pressure in the discharge passage. Further, when the compressor main body is stopped, the pressure release valve discharges the compressed gas in the discharge flow passage on the upstream side of the pressure maintaining valve and the check valve into the atmosphere, and the pressure of the discharge portion of the compressor main body. By lowering the load, the load on the drive unit at the time of restarting the compressor body is reduced, and this drive unit is prevented from being burnt out due to overcurrent or causing a compressor accident.

[0003]

In recent years, in order to improve the working environment and the like, there has been a demand from the user to reduce the noise of the compressor.
It is getting stronger and stronger. On the other hand, in the above-mentioned conventional device, when the compressor is stopped, the compressed gas in the discharge passage is formed into the atmosphere through the on-off valve. For this reason,
When the discharge gas is released to the atmosphere, a large gas emission sound is emitted from the location of the on-off valve to the surroundings of the apparatus, which causes a problem that the noise is reduced. The present invention has been made to solve the above conventional problems, and an object of the present invention is to provide a compressor capable of reducing the noise of the device.

[0004]

In order to solve the above-mentioned problems, the present invention provides a compressor body, a suction filter provided in a suction passage on the suction side of the compressor body, and a discharge pressure from a set value. And an intake control valve that narrows the suction flow path as it gets higher, and a branch from the discharge flow path upstream of the check valve provided in the discharge flow path extending to the discharge side of the compressor body,
An airflow provided with an on-off valve that opens when the compressor body stops, through which the compressed gas in the discharge flow path upstream of the check valve can be discharged to the outside of the discharge flow path. In a compressor having a passage, a suction silencer is provided at a location of a suction flow passage between the suction filter and the intake control valve, and the discharge flow passage is the suction silencer,
Alternatively, it is formed so as to communicate with any part of the suction flow path from here to the gas inflow part of the intake control valve.

[0005]

With the above structure, the compressed gas discharged from the discharge passage reaches the suction passage without being directly discharged to the atmosphere, and the compressed gas is discharged to the outside of the machine through the intake silencer. The noise is released and absorbed by the intake silencer, and the noise is absorbed by the intake silencer even during normal operation other than when air is released.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an oil-cooled screw compressor which is an example of a compressor according to a first embodiment of the present invention. A pair of male and female screw rotors housed in a rotor chamber 1 mesh with each other (one screw rotor in the drawing). (Only shown) 2
The suction passage 6 is connected to the suction port 5 of the compressor body 4 which is rotated by the drive unit 3. Then, in the suction passage 6, a suction filter 7 that removes foreign matters in the suction gas, a suction silencer 8 that absorbs noise in the suction passage 6, and an intake adjustment that adjusts the opening degree of the suction passage 6. A valve 9 is provided. On the other hand, an oil separation / recovery device 11 is provided in communication with the discharge port 10 of the compressor body 4. The oil separation / recovery device 11 includes an oil sump portion 12 at a lower portion and an oil separation element 13 at an upper portion, and is an outlet portion of the oil separation / recovery device 11 and a header portion at a position where the oil separation element 13 is discharged. 14 is provided with the pressure-holding valve 1
5, The discharge flow path 17 provided with the check valve 16 is connected.

Further, a portion of the suction flow passage 6 is branched from the discharge flow passage 17 between the header portion 14 and the pressure holding valve 15 and between the suction silencer 8 and the intake control valve 9 via the opening / closing valve 18. There is provided an air discharge channel 19 communicating with the. further,
From the lower part of the oil sump portion 12 through the temperature control valve 20, the oil cooler 21, or the temperature control valve 20, the bypass flow passage 22.
Via the oil / drain water return first passage 23 to the rotor chamber 1 in the compressor body 4 which is lower than the pressure in the oil separation / recovery device 11, and from the lower part of the header portion 14 to the oil cooler 21. An oil / drain water return second flow passage 24 is provided which joins at the side first flow passage 23.

Then, as the screw rotor 2 rotates, the suction filter 7, the suction silencer 8, the intake control valve 9
The gas sucked into the rotor chamber 1 through the suction port 5 through
The oil injected into the rotor chamber 1 through the first flow path 23 and the second flow path 24 compresses the oil while performing a sealing action and a lubricating action between the rotors, and discharges the oil from the discharge port 10 to the oil separation / collector 11. is doing. In the oil separation / recovery device 11, the oil separation element 13 separates the compressed gas from the oil, the compressed gas is sent from the header portion 14 to the discharge passage 17, and the separated oil is temporarily stored in the lower oil sump portion 12. It is like this. The oil in the oil reservoir 12 is supplied to the first flow path 23.
After that, it is re-injected into the rotor chamber 1 and is discharged together with the compressed gas from the discharge port 10 to the oil separation / recovery device 11, and thereafter is circulated and used in the same manner as described above. More specifically, the temperature control valve 20 detects the oil temperature in the first flow path 23, and when the detected temperature is higher than a set value, the temperature control valve 20 has the ports a and b in communication. The oil from the oil sump 12 is cooled through the oil cooler 21 and then injected into the rotor chamber 1.

On the other hand, when the detected temperature is equal to or lower than the set value, the temperature control valve 20 has the ports a and c in communication with each other, and the oil from the oil sump 12 passes through the oil cooler 21. Instead, it is injected into the rotor chamber 1 without being cooled through the bypass passage 22. Then, by keeping the temperature of the oil injected into the rotor chamber 1 within a certain range in this way, it is possible to prevent the oil temperature from rising excessively and accelerating the deterioration, while the temperature inside the oil separation / recoverer 11 is prevented. Is maintained at an appropriate high temperature state where drain water is not generated. Further, the open / close valve 18 provided in the discharge passage 19 is a known one that is opened when the compressor body 4 is stopped,
Thus, when the compressor body 4 is stopped, the compressed gas between the compressor body 4 and the check valve 16 is discharged from the discharge passage 19 to the outside of the machine through the suction silencer 8 and the suction filter 7. . Then, this discharge reduces the pressure of the discharge part of the compressor body 4 as described above to reduce the load on the drive part 3 when the compressor body 4 is restarted.
Prevents burnout due to overcurrent and a compressor accident.

Further, since the discharge passage 19 is formed so as to communicate with the suction passage 6 between the suction silencer 8 and the intake control valve 9 without being opened to the atmosphere, the upstream side of the check valve 16 is formed. The compressed gas is discharged to the outside of the machine through the suction silencer 8, and noise at the time of discharge is absorbed by the suction silencer 8 and reduced. Further, even during normal operation other than when air is released, noise from the compressor body 4 is reduced by the suction silencer 8. FIG. 2 shows an oil-cooled screw compressor which is an example of a compressor according to a second embodiment of the present invention, and the portions common to the compressor shown in FIG. Omit it. In the second embodiment, the intake control valve 9 is provided with a pressurizing chamber 26 which is separated from the space forming the suction passage 6 by a diaphragm 25,
A valve body 27 for adjusting the flow passage cross-sectional area of the gas inflow portion of the intake air control valve 9 and a spring 28 positioned between the valve body 27 and the diaphragm 25 are provided in the space forming the suction flow passage 6. There is. Further, in order to guide the pressure inside the header portion 14 into the pressurizing chamber 26 so that the pressure inside the header portion 14 can be appropriately reduced, the header portion 14
A gas passage 30 is provided to connect the pressure chamber 26 with the pressure chamber 26 via a pressure control valve 29.

A pressure switch 31 is provided in the discharge flow passage 17 so that pressure can be detected. As will be described in detail below, when the detected pressure becomes higher than a set value, the drive unit 3 is driven via a timer 32. On the other hand, it is formed so as to output an off signal for stopping this. Further, a drain water removal discharge passage 33 is provided which branches from the discharge passage 17 on the downstream side of the check valve 16 and communicates with the location of the suction passage 6 between the suction silencer 8 and the intake control valve 9. There is. In addition, an orifice 34 is provided in the discharge passage 33 for drain water removal.
When the timer 32 is operating on the output side thereof, that is, after the timer 32 receives an off signal from the pressure switch 31,
On the other hand, an electromagnetic on-off valve 35 which is open until the OFF signal is output (time t ₀ ) is provided.

Then, as in the first embodiment, the compressed gas from the drain water removing air flow passage 33 is not directly discharged into the atmosphere but is discharged outside the machine through the suction silencer 8. , The noise at the time of exhalation is absorbed by the suction silencer 8,
It is being reduced. Further, as shown by the broken line Y in the upper part of FIG. 3, for example, as the pressure in the header portion 14 becomes higher than the set pressure P1, the pressure in the pressurizing chamber 26 also becomes higher, and the diaphragm 25 is left in FIG. When the valve body 27 is pushed toward the left side and curved, the valve body 27 is moved to the left, and as a result, the valve body 27 gradually reduces the flow passage cross-sectional area of the gas inflow portion of the intake air control valve 9, and finally, In FIG. 3, the pressure P2
When (P2> P1), the gas inflow portion is completely closed, and the compressor is brought into a no-load (unloading) operation state. Further, as shown in the middle part of FIG. 3, when the detected pressure is higher than a set value, for example, the pressure P1 in this embodiment, the pressure switch 31 is turned on, and the driving unit of the screw rotor 2 starts from here. An off signal for stopping 3 is output. This off signal is
It is input to the timer 32 interposed between the pressure switch 31 and the drive unit 3, and as shown in the lower part of FIG. 3, after the set time t _{0 has} elapsed after receiving the OFF signal, the timer 32 instructs the drive unit 3 to proceed. To output the off signal. Here, the horizontal axis is shown with reference to the time point when the pressure P1 is reached (t = 0).

In FIG. 3, the set pressure and the pressure switch 31 for starting the transition of the intake control valve 9 from the fully open state to the fully closed state are shown.
Although the same set pressure for on / off switching is shown, the set pressures do not necessarily have to be the same.
Further, the branch point of the drain water removal air discharge passage 33 from the discharge passage 17 may be on the upstream side of the check valve 16.
Since the timer 31 is interposed between the pressure switch 30 and the drive unit 3 as described above, the drive unit 3 does not immediately stop even when the discharge pressure becomes higher than the set value, and the intake control valve 9 is not immediately stopped. Of the compressor main body 4 under the condition that the amount of suction gas decreases and approaches the no-load operation, and the amount of water newly dissolved in the gas in the oil separation and recovery unit 11 is decreasing. Will be activated for a set time and then stopped. Then, during the operation for this set time, the drain water that has precipitated in the oil separation / recovery device 11 is returned from the lower part of the oil sump portion 12 together with the oil into the rotor chamber 1, and is mixed with the gas whose temperature has been increased by the compression. Since it is sent out to the discharge flow path 17 together with it, the drain water is efficiently removed from the oil separating and collecting unit 11.

Since the temperature in the header portion 14 is lower than the temperature in the space portion on the discharge port side of the oil separation element 13 in the oil separation / collector 11, drain water is deposited in the header portion 14. However, the drain water deposited here is returned to the rotor chamber 1 via the second flow path 24 together with the oil scattered from the oil separation element 13, and this drain water is also mixed with the compressed gas and discharged. It is sent to the flow path 17. Therefore, conversely, the above set time is
This is a time sufficient to completely discharge the drain water deposited in the oil separation / recovery device 11 to the discharge flow path 17, and this time is, for example, when the compressor is operated and the oil separation / recovery device 11 is actually operated. It can be easily determined by observing the oil. That is, when the drain water is deposited in the oil during operation of the compressor, the oil is white and turbid, and conversely, when the drain water is not present, the oil is in a transparent state. Therefore, the pressure switch 31 is turned off. After the signal is output, the set time may be determined by actually measuring how much time has elapsed until the oil in the oil separating and collecting device 11 becomes transparent.

Further, by forming as described above, there is no need to provide any dedicated pipe for drain water removal from the oil separation / recovery device 11, and therefore, a valve associated with the pipe is not required, and a simple structure is provided. The maintenance work for drain water drainage is completely unnecessary. Also,
Immediately after the off signal is output from the pressure switch 31,
Since the drive unit 3 is not stopped, the drive unit 3 is not frequently turned on and off repeatedly even if the pressure fluctuates in a short time, and the drive unit 3 can be prevented from being overheated. By the way, before and after the timing at which the drive unit 3 is turned off and the timing at which the intake control valve 9 is fully closed, there is no limitation, but by adjusting the opening / closing speed of the intake control valve 9, the pressure in FIG. After the switch 31 is turned on and outputs an off signal, the intake control valve 9 is fully closed within a time shorter than the time t ₀ (for example, 5 minutes) until the drive unit 3 is turned off, that is, stopped. It may be possible to put it in a state. In this case, since the gas in the compressor is not delivered to the outside of the compressor after the intake control valve 9 is fully closed, for example, when the suction gas contains a large amount of water, water remains in the gas in the compressor. there is a possibility.

Therefore, in this embodiment, by keeping the open / close valve 35 in the open state during the operation of the timer 32, even if the intake control valve 9 is fully closed as described above, The discharge channel 33 for drain water removes the gas from the compressor together with the moisture to the outside of the machine, and does not leave the moisture in the compressor regardless of the opening / closing speed of the intake control valve 9 to prevent the generation of drain water. . Further, by adjusting the throttling ratio of the orifice 34, the speed of the pressure drop in the oil separation / recovery device 11 can be adjusted, and thus the opening / closing speed of the intake control valve 9 can be adjusted. Specifically, the polygonal lines X, Y, and Z in the upper part of FIG. 3 show an example in which the aperture ratio is increased in this order, and the polygonal line X is the case where the aperture ratio is the smallest. As the squeezing ratio increases, the water release rate from the compressor decreases. However, when the opening adjustment speed of the intake air control valve 9 is appropriate, this orifice 34 is not always necessary. In addition, although the oil-cooled screw compressor has been described in the above embodiment, the present invention is not limited to the oil-cooled type, and is not limited to the screw type. Further, the discharge passage 19 and the drain water removal discharge passage 33 may be directly connected to the suction silencer 8 unlike the above embodiment. Further, the present invention is not limited to the one having the pressure holding valve 15.

[0017]

As is apparent from the above description, according to the present invention, the compressor main body, the suction filter provided in the suction passage on the suction side of the compressor main body, and the discharge pressure more than the set value. The intake control valve that narrows the suction flow path as it rises and the check valve provided on the discharge flow path that extends to the discharge side of the compressor main body are branched from the discharge flow path upstream of the check valve An on-off valve that is opened when the machine body is stopped, and a discharge channel formed so that the compressed gas in the discharge channel on the upstream side of the check valve can be discharged to the outside of the discharge channel via this on-off valve. In the compressor provided with, a suction silencer is provided in the suction flow path between the suction filter and the intake control valve, and the discharge flow path is provided with the suction silencer, or the gas inflow part of the intake control valve from there. To any part of the suction flow path leading to It is formed. Therefore, the gas released from the discharge passage reaches the suction passage directly without being released to the atmosphere, the compressed gas is released outside the machine through the intake silencer, and noise is absorbed by the intake silencer. At the same time, noise is absorbed by the suction silencer during normal operation other than when air is released, and as a result, it is possible to reduce the noise of the device.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an oil-cooled screw compressor according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of an oil-cooled screw compressor according to a second embodiment of the present invention.

FIG. 3 is a diagram showing the interrelationship of the operation of the intake control valve, the pressure switch, and the drive unit in the compressor shown in FIG.

[Explanation of symbols]

 4 Compressor body 6 Suction flow path 7 Suction filter 8 Suction silencer 9 Intake control valve 16 Check valve 17 Discharge flow path 18 Open / close valve 19 Exhaust flow path

Claims (1)

[Claims] 1. A compressor main body, a suction filter provided in the suction flow passage on the suction side of the compressor main body, and an intake control valve that narrows the suction flow passage as the discharge pressure becomes higher than a set value. , Branched from the discharge flow passage on the upstream side of the check valve provided in the discharge flow passage extending to the discharge side of the compressor body,
An airflow provided with an on-off valve that opens when the compressor body stops, through which the compressed gas in the discharge flow path upstream of the check valve can be discharged to the outside of the discharge flow path. In a compressor having a passage, a suction silencer is provided at a location of a suction flow passage between the suction filter and the intake control valve, and the discharge flow passage is the suction silencer,
Alternatively, the compressor is characterized by being formed so as to communicate with any part of a suction flow path from here to the gas inflow part of the intake control valve.