JPH05141350A - Method and device for preventing rusting of compressor during rest of operation - Google Patents

Abstract

PURPOSE:To prevent the occurrence of rusting without the occurrence of wear and peel owing to high temperature high speed rotation of a compressor by substituting gas containing a remaining moisture content with dry gas, containing a less amount of a moisture content, through suction of the dry gas to a compressor when the compressor is brought into an operation rest. CONSTITUTION:During normal running of a compressor, when after an on-off valve 11 is closed and gas is compressed through drive of a compressor body 1, the compressed gas is fed in a cooler 4, the compressed gas is cooled and discharged. During the rest of operation, when the on-off valve 11 is opened, compressed dry gas from a sealing gas feed source 12 is fed through a dry gas feed line 11' and a suction piping to a compressor body 1, a delivery pipping, and a cooler 4, gas containing a remaining moisture content is pushed out. Thereafter, when the compressor body 1, the delivery piping, and the cooler 4 are full of dry gas, the on-off valve 11 is closed. In this case, since the compressor is sealed with gas containing entirely no moisture content or gas containing a small amount of a moisture content, the interior of the compressor can be prevented from rusting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor rust preventive method and a rust preventive device at the time of non-operation, and more particularly to a compressor rust preventive method at the time of non-operation, which is suitable for economy and slidability. Regarding rust prevention equipment.

[0002]

2. Description of the Related Art In a conventional screw compressor, for example, as described in JP-A-56-14895,
Gas and oil are separated for the oil-mixed screw compressor,
In particular, a method for removing water contained in oil has been proposed, but no consideration is given to corrosion and rusting due to water contained in gas.

Further, as a method for preventing rust of a screw compressor,
For example, there are methods such as applying anti-corrosion coating on the surface of the rotor and the inner surface of the compressor body casing, and changing the parts where corrosion and rust are a problem to corrosion resistant materials such as stainless steel. There is. Also, when the compressor operation is stopped, unloading operation is performed for a predetermined time,
A method of removing the water content of the gas in the path from the intake valve installed on the intake side of the first-stage compressor to the blow-off valve installed on the discharge side of the final stage is practiced.

[0004]

The above-mentioned prior art has the following problems.

First, in the method of applying a rust preventive coating, the rust preventive material cannot withstand the environmental conditions such as high temperature and high speed rotation of the compressor, and there is a possibility that the rust preventive effect is lost due to abrasion and peeling. was there. Further, the method of using a corrosion resistant material such as stainless steel has many problems in economy and slidability, and is difficult to put into practical use.

An object of the present invention is to prevent the compressor from being out of operation without causing wear or peeling at high temperature and high speed rotation of the compressor, and improving economy and slidability. It is to provide a rust method and a rust preventive device.

[0007]

In order to achieve the above object, the first invention is to suck a dry gas containing no water or only a small amount into the compressor when the compressor is stopped. Then, the gas containing water remaining in the compressor is replaced with a dry gas for sealing.

As the dry compressed gas, a dry gas obtained by removing moisture by a dehumidifying device provided in a suction pipe or a discharge pipe of the main body of the compressor is used.

The dry compressed gas uses the dry compressed gas stored in the enclosed gas supply source.

In order to achieve the above object, a fourth aspect of the invention is to provide a dry gas sealing line connected to the suction side of the compressor body, and to provide an opening / closing valve and a dry gas supply source in the dry gas sealing line. Is.

In order to achieve the above object, a fifth aspect of the present invention is to provide a dehumidifying device on the discharge pipe of the compressor body, and connect the discharge side of the dehumidifying device of the discharge pipe to the suction pipe of the compressor body. With a dry gas filling line,
An on-off valve is provided in the dry gas sealing line.

In order to achieve the above object, a sixth aspect of the present invention is to provide a suction valve in a suction pipe of a compressor body, a blow-off valve check valve and a dehumidifying device in a discharge pipe, and to dehumidify the discharge pipe. While connecting the device discharge side to the suction pipe,
A dry gas sealing line having an opening / closing valve is provided, and a control means for controlling the opening / closing of the suction valve, the blow-off valve and the opening / closing valve is provided.

In order to achieve the above object, a seventh aspect of the invention is to provide a low pressure side suction pipe with a low pressure side suction valve and a low pressure side discharge pipe with an intercooler, and a low pressure side discharge body. In a multi-stage compressor having a suction side connected to a pipe and a high pressure side discharge pipe having a blow-off valve, a check valve, and a final stage compressor body having an aftercooler, a dehumidifier is provided in the high pressure side discharge pipe, A control for providing an open / close valve in the dry gas sealing line connecting the high pressure side discharge pipe and the low pressure side discharge pipe on the discharge side of the dehumidifier and for controlling the open / close of the low pressure side intake valve, the blowoff valve and the open / close valve. Means are provided.

The above-mentioned control means is provided in the high-pressure side discharge pipe, and is provided with dew-point temperature detecting means for detecting the dew-point temperature of the high-pressure side discharge pipe.

The above dehumidifying device dries a gas containing water by using a desiccant.

[0016]

According to the first aspect of the present invention, when the compressor is stopped, a dry gas containing no or only a small amount of water is sucked into the compressor to remove the wet gas remaining in the compressor. Since it is replaced with a dry gas and sealed, rusting can be prevented while the compressor is not operating.

According to the second aspect of the invention, since the dry compressed gas is the dry compressed gas from which moisture has been removed by the dehumidifying device installed in the discharge pipe of the compressor, it is necessary to install the enclosed gas supply source. Absent.

According to the third aspect of the invention, since the compressed gas used is a dry compressed gas supplied from a sealed gas supply source, the dry gas can be sucked into the compressor at any time.

According to the fourth aspect of the invention, when the compressor is not in operation, and when the on-off valve provided in the dry gas sealing line connected to the suction side of the compressor main body is opened during operation stop, the dry gas sealing line is opened. Since the dry compressed gas from the provided enclosed gas supply source is sucked into the compressor main body and discharges the gas containing water remaining in the compressor main body and the discharge pipe to the outside, the inside of the compressor is changed to the dry gas at any time. It can be replaced and encapsulated.

According to the fifth aspect of the present invention, when the compressor is stopped, the on-off valve provided in the discharge gas pipe of the compressor body and the dry gas sealing line connected to the suction side of the compressor body is opened. Since the dry compressed gas from the dehumidifying device provided in the discharge pipe is sealed in the compressor body through the dry gas sealing line, it is not necessary to install a dry compressed gas supply facility.

According to the sixth aspect of the invention, when the compressor is stopped, the control means first closes the intake valve, and
Open the blow-off valve and perform unloading operation to release the gas containing water remaining in the compressor body from the blow-off valve to the outside, and then open the on-off valve to release the dry compressed gas from the dehumidifier into the compressor body. The residual water in the compressor body and the discharge pipe is removed by the pressure difference by sucking it to the suction side of the compressor, so the compressor is unloaded and the dry compressed gas is sucked in. It is possible to reliably prevent rusting inside the compressor without changing the material.

According to the seventh aspect of the invention, when the multistage compressor is stopped, the control means closes the low pressure side intake valve of the main body of the intermediate stage compressor, opens the blow-off valve, and performs the unloading operation to perform the intermediate operation. After releasing the gas containing moisture remaining in the main body of the stage compressor and the body of the final stage compressor to the outside from the blow-off valve, open the on-off valve and dry the compressed compressed gas stored in the gas tank to the body of the final stage compressor. The water remaining in the final stage compressor body is discharged from the blowoff valve due to the pressure difference when sucked into the inside.

Therefore, it is possible to reliably prevent rusting after the suspension of operation of the compressor without coating the interior of the compressor with a rust preventive paint or changing the material to a material having excellent corrosion resistance.

According to the eighth aspect of the invention, since the dew point temperature detecting means connected to the control means is provided in the discharge pipe of the main body of the high pressure stage compressor, the dew point temperature in the compressor can be easily detected from the outside. As a result, it is possible to reliably prevent the generation of water while the compressor is stopped.

According to the ninth invention, since the desiccant is used in the dehumidifying device, the gas containing water can be replaced with the dry gas at an early stage.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the present invention will be described below with reference to FIG. It should be noted that FIG. 1 shows a case in which the minimum necessary devices are installed to describe the first, third, and fourth inventions, and other devices may be installed.

As shown in FIG. 1, a dry gas sealing line 11A is connected to the suction pipe 1A of the compressor body 1 at a position C, and the dry gas sealing line 11A has an opening / closing valve 11 and a sealed gas supply source 12. Is installed. The sealed gas supply source 12 is filled with a sealed gas containing no water or only a small amount of water. A cooler 4 is installed in the discharge pipe 1B of the compressor body 1.

Next, the operation will be described. During normal operation of the compressor, when the on-off valve 11 is closed and the gas from the suction pipe 1A is compressed by the drive of the compressor main body 1 and then sent into the cooler 4 through the discharge pipe 1B, the compressed gas is discharged. It is cooled and discharged again through the discharge pipe 1B. When the operation of the compressor is stopped, the on-off valve 11 is opened and the compressed dry gas from the enclosed gas supply source 12 passes through the dry gas supply line 11A and the suction pipe 1A, and the compressor body 1, the discharge pipe 1B and the cooler 4 are provided. When supplied into the inside, the gas containing the residual water is extruded. After that, the compressor body 1,
When the discharge pipe 1B and the cooler 4 are filled with the dry gas, the on-off valve 11 is closed. Therefore, the compressor is sealed with a gas containing no water or only a small amount of water, so that rusting inside the compressor can be prevented. Although the above embodiment shows the case where the enclosed gas supply source is installed separately from the discharge pipe, the present invention is not limited to this, and a dehumidifier is installed in the discharge pipe to remove dehumidification from the dehumidifier. It is also possible to supply the dry gas to the suction side of the compressor body.

Next, FIG. 2 showing a second embodiment in which the present invention is applied to a single-stage compressor will be described.

As shown in the figure, the suction pipe 1A of the compressor body 1 is provided with a suction valve 6, and the discharge pipe 2A is provided with a check valve 5, an aftercooler 4 and a dehumidifying device 10, and a tip portion. The gas tank 14 is provided in the. Further, a blowoff valve 7 is provided in the discharge distribution pipe 2B branched from the middle of the discharge pipe 2A. Further, an opening / closing valve 11 is provided in a dry gas sealing line 11A that branches from the position A between the dehumidifying device 10 of the discharge pipe 2A and the gas tank 14 and is connected to the middle of the suction pipe 1A. A drive unit 8 and a control unit 9 are provided in the control means for controlling the opening / closing of the intake valve 6, the blow-off valve 7 and the opening / closing valve 11.

Next, the operation will be described. During the ventilation operation of the compressor, the intake valve 6 is opened and the blowoff valve 7 and the on-off valve 11 are closed by the control means. When the gas is sucked into the compressor main body 1 from the suction pipe 1A, the gas is compressed and cooled by the aftercooler 4 through the discharge pipe 2A, and after the moisture is removed from the wet gas by the dehumidifying device 10 to be a dry gas, It is introduced into the gas tank 14.

When the compressor is not in operation, first the control means closes the intake valve 6 and the on-off valve 11 and opens the blowoff valve 7,
When the compressor body 1 is continuously driven, the compressor body 1 enters the unloading operation state, and the compressor body 1 and the discharge distribution pipe 2 are
The gas containing water remaining in B is discharged from the blow-off valve 7 to the outside air. After that, when the blow-off valve 7 is closed and the on-off valve 11 is opened by the control means, the dry compressed gas stored in the gas tank 14 is sucked into the compressor body 1 through the dry gas sealing line 11A due to the pressure difference. .. Therefore, it is possible to prevent rusting during the suspension of the operation of the compressor without applying the rust preventive paint or changing the material to a material having excellent corrosion resistance.

Next, FIG. 3 showing an example applied to the multi-stage compressor which is the third embodiment of the present invention will be explained.

As shown in the figure, a suction valve 6 is provided in the low pressure side intake pipe 1A of the intermediate stage compressor body 1, an intercooler 3 is provided in the low pressure side discharge pipe 1B, and the tip end thereof is It is connected to the suction side of the stage compressor body 2.
A check valve 5, an aftercooler 4, and a dehumidifying device 10 are provided in the high-pressure side discharge pipe 2A of the final stage compressor body 2, and the tip portion thereof is connected to the gas tank 14. Further, a discharge distribution pipe 2B branched from the middle of the high pressure side discharge pipe 2A.
A blow-off valve 7 is provided in the. High pressure side discharge pipe 2
An on-off valve 11 is provided in the dry gas charging line 11A that branches from the position A between the dehumidifying device 10 of A and the gas tank 14 and is connected to the low pressure side discharge pipe 1B. The low-pressure side intake valve 6, the blow-off valve 7, and the opening / closing valve 11 are controlled to be opened / closed by the control means including the drive device 8 and the control device 9 as described in the following operation.

Next, the operation will be described. During normal operation of the compressor, the low pressure side intake valve 6 is opened by the control means,
The blowoff valve 7 and the on-off valve 11 are closed. When the gas from the low pressure side suction pipe 1A is sucked into the intermediate stage compressor body 1,
The gas is compressed, cooled by the intercooler 3 provided in the low pressure side discharge pipe 1B, and then sucked into the final stage compressor body 2. The gas sucked into the high-pressure compressor 2 is further compressed, cooled by the aftercooler 4 through the high-pressure side discharge pipe 2A, then replaced by the dry high-pressure gas in the dehumidifier 10 and introduced into the gas tank 14. To be done. When the operation of the compressor is stopped, first, the intake valve 6 is closed by the control means, the blowoff valve 7 is opened, and the intermediate stage compressor body 1 and the final stage compressor body 2 are continuously driven to enter the unloading operation state. Then, when the on-off valve 11 is opened by the control means, the dry high-pressure gas stored in the gas tank 14 is filled with the dry gas sealing line 11A.
And high pressure stage compressor body 2 through low pressure side discharge pipe 1B
The gas containing water, which is sucked into the high pressure stage compressor body 2 and remains in the main body 2 of the high pressure stage, is discharged to the outside from the blowoff valve 7 through the discharge distribution pipe 1C. The reason why the tip end of the dry gas sealing line 11A is not connected to the low-stage suction pipe 1A is that the intermediate-stage compressor body 1 maintains a vacuum state by unloading operation,
This is because the gas containing water is sucked into the final stage compressor body 2. Therefore, by utilizing the pressure difference, it is possible to prevent rusting in the compressor without installing an enclosed gas supply source.

Next, FIG. 4 showing another example in which the present invention is applied to a multi-stage compressor will be described. 3 and FIG. 3 are different in that the dew point temperature detecting means 15 connected to the control device 9 is provided in the high-pressure side discharge pipe 2A, and other points are the same, so only the different points will be described. FIG. 3
As described above, the intermediate stage compressor body 1 and the final stage compressor body 2 are unloaded, and then the opening / closing valve 11 is opened to suck the dry high-pressure gas from the gas tank 14 into the final stage compressor body 2. Then, the gas containing water remaining in the final stage compressor body 2 is blown to the outside from the blow-off valve 7 through the discharge distribution pipe 2B to reach the check valve 5 in front of the high-pressure side discharge pipe 2A. When the dew point temperature reaches a preset temperature, the on-off valve 13 is closed. Also, when the dew point temperature in the high pressure side discharge pipe 2A changes while the compressor is not operating,
The above operation is performed according to a command from the dew point temperature detecting means 15. Therefore, since water inside the compressor is removed while the compressor is not operating, rusting can be reliably prevented.

[0037]

Since the present invention is constructed as described above, the following effects can be obtained.

According to the first aspect of the invention, when the compressor is not operating, the gas containing water remaining in the compressor is discharged to the outside by the dry gas containing no water or only a small amount of water, and dried. Since it is replaced by gas and sealed, rusting can be prevented even when the compressor is hot and rotates at high speed without considering abrasion and peeling of rust-preventive paints, etc., thereby improving economic efficiency and slidability. it can.

According to the second invention, since the dry gas from the dehumidifying device provided in the discharge pipe of the compressor body is used as the dry gas, it is not necessary to install a sealed gas supply source.

According to the third invention, since the dry gas from the enclosed gas supply source is used as the dry gas, the dry gas can be sucked into the compressor at any time.

According to the fourth aspect of the invention, the dry compressed gas from the enclosed gas supply source can be sucked into the compressor at any time during the operation stop of the compressor and during the operation stop.

According to the fifth aspect of the invention, when the compressor is not in operation, dry compressed gas from the dehumidifying device provided in the discharge pipe of the compressor body is sucked into the compressor body and remains inside the compressor body. Since the gas containing moisture that is used is replaced by a dry gas and sealed,
It is possible to prevent rusting while the compressor is not operating.

According to the sixth aspect of the present invention, when the compressor is not in operation, first the unloading operation is performed to release the residual gas in the compressor to the outside, and then the dry compressed gas stored in the gas tank is removed. It is sucked into the suction side of the compressor body, and the moisture inside the compressor is discharged to the outside due to the pressure difference and enclosed with a dry gas, so it is not necessary to apply a rust-preventive paint or change the material to a material with excellent corrosion resistance. It is possible to reliably prevent rust inside the compressor.

According to the seventh aspect of the present invention, when the operation of the multi-stage compressor is stopped, first, the unloading operation is performed, and the wet gas remaining inside the low-pressure stage compressor body and the high-pressure stage compressor body is discharged from the blow-off valve. After being discharged to the outside, the dry compressed gas stored in the gas tank is sucked into the main body of the high-pressure stage compressor, and the wet gas remaining in the main body of the high-pressure stage compressor is released to the outside from the blow-off valve. It is possible to reliably prevent rust after the compressor is stopped without applying a rust preventive paint or changing the material to a material having excellent corrosion resistance.

According to the eighth aspect of the invention, since the dew point detecting means connected to the control means is provided in the discharge pipe of the main body of the high pressure stage compressor, the dew point temperature in the compressor can be easily detected from the outside. With this, it is possible to automatically prevent dew condensation from occurring while the compressor is stopped.

According to the ninth invention, since the desiccant is used in the dehumidifying device, the wet gas can be dried at an early stage.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... Compressor body, low pressure stage compressor body, 2 ... High pressure stage compressor body, 3 ... Intercooler, 4 ... After cooler, 5 ...
Check valve, 6 ... Intake valve, 7 ... Check valve, 8 ... Drive device, 9 ...
Control device, 10 ... Dehumidifying device, 11, 13 ... Open / close valve, 11
A ... Dry gas filling line, 12 ... Filling gas supply source, 14
... Gas tank, 15 ... Dew point temperature detecting means, 16 ... Dehumidifier.

Claims (9)

[Claims] 1. When the compressor is stopped, a dry gas containing no or only a small amount of water is sucked into the compressor to replace the gas containing water remaining in the compressor with the dry gas. A method for preventing rusting of compressors during operation stop, which is characterized by encapsulation. 2. The dry gas used is a dry gas from which water has been removed by a dehumidifying device provided in a suction pipe or a discharge pipe of the compressor main body.
How to prevent rusting of the compressor when the operation is stopped. 3. The dry compressed gas stored in an enclosed gas supply source is used as the dry gas.
How to prevent rusting of the compressor when the operation is stopped. 4. A compressor at the time of operation stop, wherein a dry gas sealing line connected to the suction side of the compressor body is provided, and an opening / closing valve and a dry gas supply source are provided at the dry gas sealing line. Anticorrosion device. 5. A dehumidifying device is provided in the discharge pipe of the compressor main body, and a dry gas sealing line is provided for connecting the discharge side of the dehumidifying device of the discharge pipe and the suction pipe of the compressor main body. A rust preventive device for compressors when operation is stopped, which is equipped with an on-off valve in the sealing line. 6. A suction valve is provided in the suction pipe of the compressor body, a blow-off valve check valve and a dehumidifier are provided in the discharge pipe, and the suction side of the dehumidifier discharge side of the discharge pipe and the compressor body A compressor in operation stop, which is connected to a pipe, is provided with a dry gas sealing line having an opening / closing valve, and is provided with control means for controlling opening / closing of the suction valve, the blow-off valve and the opening / closing valve. Anti-corrosion device. 7. The low pressure side intake pipe has a low pressure side intake valve,
An intermediate stage compressor body having an intercooler in the low pressure side discharge pipe, and a final stage compressor body having a blower valve, a check valve, and an aftercooler in the high pressure side discharge pipe, with the suction side connected to the low pressure side discharge pipe. In the multi-stage compressor consisting of, the dehumidifying device is provided in the high pressure side discharge pipe, and an opening / closing valve is provided in a dry gas sealing line connecting the high pressure side discharge pipe and the low pressure side discharge pipe on the dehumidifying device discharge side, and A rust preventive device for a compressor at the time of operation stop, comprising control means for controlling opening / closing of the low pressure side intake valve, the blowoff valve and the open / close valve. 8. The control means comprises a dew-point temperature detecting means installed in the high-pressure side discharge pipe and detecting a dew-point temperature of the high-pressure side discharge pipe. The rust preventive device for the compressor when the operation is stopped as described in (1). 9. The rust preventive device for a compressor during an operation stop according to claim 5, wherein the dehumidifying device dries the gas using a desiccant.