JP2005351255A - Reciprocating compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating compressor in which leak of gas from a piston ring is not avoidable and leaking gas can be automatically recovered into a suction gas flow passage after cooling. <P>SOLUTION: Leaking gas from a piston seal part is recovered by providing a communication passage 14 always making communication between an upstream of a check valve 10 provided in the suction gas flow passage 12 and a non-compression side 7 of a cylinder, and a seal part 5 of a piston rod. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a reciprocating compressor in which a piston reciprocates linearly in a cylinder to compress gas.

    Normally, a compressor that reciprocates a piston by a crank mechanism is often used as a gas reciprocating compressor. However, a compressor having this structure avoids that a part of the compressed gas leaks from the seal portion of the piston. In most cases, the leaked gas was released into the atmosphere. However, when compressing at a high pressure ranging from several tens of atmospheres to several hundreds of atmospheres, the amount of the leaked gas is increased, and its recovery has been a problem in terms of economy and safety.

    As a method for collecting the leaked gas, conventionally, a separate gas holder is installed, the entire compressor is sealed, the leaked gas is guided to the gas holder and stored, and compressed again to return to the original gas line. The method was general. However, this method has the disadvantage that a gas holder and another compressor are required, which requires a large amount of equipment and increases costs.

    The present invention makes it possible to recover the gas leakage from the piston seal portion in the reciprocating compressor only by adding a simple mechanism.

    The present invention relates to a so-called reciprocating compressor in which a piston reciprocates in a cylinder to compress gas, and a gas sealing mechanism is provided at a cylinder entrance / exit portion of a piston rod, and a gas inflow passage sucked into a cylinder compression side And a non-compressed side of the cylinder is provided with a gas communication path that is always in communication regardless of the reciprocation of the piston.

    This communication path and piston rod seal always apply the same gas pressure to the non-compressed side of the cylinder as the suction flow path, but the amount of gas leaking from this piston rod seal is compared to that of the piston seal. As a result, the differential pressure applied to the seal portion is remarkably small, and the seal area is small.

    As the piston reciprocates, gas enters and exits the non-compressed side of the cylinder through the communication path. This gas naturally contains a small amount of high-temperature gas that leaks from the compression side of the cylinder through the piston seal, and is connected to the suction-side flow path, so the temperature of the compression-side intake gas rises. Causes the performance of the compressor to deteriorate. Another feature is that the communication path is provided with a cooling mechanism for preventing this.

    As described above, the reciprocating compressor of the present invention can recover the leaked gas from the piston seal portion after automatically cooling it into the intake gas flow path.

    The best mode for carrying out the present invention is to provide a through hole at the rearmost portion of the non-compression side of the cylinder and connect it to pull out the pipe, and connect it before the check valve of the cylinder compression side suction pipe. And it is providing a cooler in the middle of this connection piping.

    FIG. 1 shows an embodiment of the present invention. The suction gas is sucked into the compression side 6 of the cylinder 1 from the compression side suction port 8 of the cylinder 1 through the suction side flow valve 12 through the suction side check valve 10, and is compressed by the reciprocating motion of the piston 2 to be compressed side discharge port 9. Further, the gas is discharged to the discharge gas passage 13 through the discharge side check valve 11. The non-compression side 7 of the cylinder 1 is provided with a communication path 14 that is in front of the suction-side check valve 10 and communicates with the suction gas flow path 12, and further, a cooler 17 is provided in the communication path 14. ing. 2 is a piston, 3 is a piston seal, 4 is a piston rod, 5 is a piston rod seal, 15 is a driving mechanism for reciprocating the piston, and 16 is a cooling water jacket for cooling the cylinder.

The non-compressed side 7 of the cylinder is hermetically sealed by the piston seal 3 and the piston rod seal 5, and is communicated with the suction gas passage 12 through the communication passage 14, so that the internal pressure is always kept regardless of the reciprocation of the piston. The same pressure as the pressure in the passage 12 is maintained.
Therefore, even when a part of the gas compressed to high pressure and high temperature by the reciprocation of the piston 2 leaks from the piston seal 3 to the non-compressed side 7 of the cylinder, the leaked gas is not discharged directly to the outside. It is recovered in the suction gas flow path 12 through the non-compressed side 7 of the cylinder and the communication path 14.

    In addition, if the cooler 17 is disposed in the communication passage 14, an increase in temperature due to the leaked gas can be prevented. As a result, an increase in the temperature of the intake gas passage 12 can be suppressed, and a reduction in the suction efficiency of the compressor can be prevented. it can. A water-cooled heat exchanger or an air-cooled heat exchanger is suitable as the cooler, but natural heat dissipation is also possible when the amount of leaked gas is very small.

    The leaked gas from the cylinder 1 may be leaked from the piston rod seal 5 on the non-compressed side 7, but the pressure of the gas on the non-compressed side 7 is substantially the same as the pressure of the suction gas flow path. The differential pressure of the piston rod seal 5 is smaller than that of the piston seal 3, and the pressure difference between the piston 2 and the piston rod 3 is smaller than that of the piston seal 3. The amount of leakage from the piston rod seal 5 is greatly reduced compared to the amount of leakage from the piston seal portion.

    As a result, most of the leaked gas from the piston seal 3 is recovered in the intake gas flow path 12, which greatly increases the economy of the compressor.

It is sectional drawing of the reciprocating compressor concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Piston seal 4 Piston rod 5 Piston rod seal 6 Cylinder compression side 7 Cylinder non-compression side 8 Compression side suction port 9 Compression side discharge port 10 Suction side check valve 11 Discharge side check valve 12 Intake gas Flow path 13 Discharge gas flow path 14 Communication path 15 Driving mechanism 16 Cooling water jacket 17 Cooler

Claims (2)

    In a reciprocating compressor in which the piston reciprocates in the cylinder, a sealing mechanism is provided to seal the gas in the cylinder to the piston rod on the non-compression side of the cylinder, and the non-compression side of the cylinder is a non-return on the compression side gas suction flow path. A reciprocating compressor characterized in that a communication passage that is always in communication with the front side of the valve is provided.     The reciprocating compressor according to claim 1, wherein a cooler is provided in the communication path of claim 1.

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