Multi-stage gas compressing apparatus

Abstract

A compressed gas compressed by the first gas compressor is further compressed by the second gas compressor. The compressed gas from the first gas compressor is sent to a crank case of the second gas compressor in which the gas is further compressed. The gas is sent to a cylinder of the second gas compressor and compressed by a piston in the cylinder.

1 . A multi-stage gas compressing apparatus comprising:
 a first gas compressor comprising a first driving shaft, a first crank case, a first introducing conduit through which a compressed gas is introduced into the first crank case, a first driving shaft extending through the first crank case, a first crankshaft coupled to the first driving shaft to rotate with the first driving shaft, a first connecting rod rotatably mounted at one end to the first crankshaft, a first cylinder on the first crankcase, a first piston coupled at the other end to the first connecting rod in the first cylinder to move up and down with rotation of the first crankshaft, a first sucking chamber communicating with the first cylinder, a first connecting conduit connecting the first crankcase to the first sucking chamber, the compressed gas being introduced from the first crank case to the first sucking chamber through the first connecting conduit so that the compressed gas is compressed by the first piston in the first cylinder communicating with the first sucking chamber; and a first discharge chamber communicating with the first cylinder to allow the compressed gas to be discharged from the cylinder through the first discharge chamber; and   a second gas compressor comprising a second driving shaft, a second crank case, a second introducing conduit through which the compressed gas is introduced from the first discharge chamber of the first gas compressor into the second crank case, a second driving shaft extending through the second crank case, a second crankshaft coupled to the second driving shaft to rotate with the second driving shaft, a second connecting rod rotatably mounted at one end to the second crankshaft, a second cylinder on the second crankcase, a second piston coupled at the other end to the second connecting rod in the second cylinder to move up and down with rotation of the second crankshaft, a second sucking chamber communicating with the second cylinder, a second connecting conduit connecting the second crankcase to the second sucking chamber; the compressed gas being introduced from the second crank case to the second sucking chamber through the second connecting conduit so that the compressed gas is further compressed by the second piston in the second cylinder communicating with the second sucking chamber, and a second discharge chamber communicating with the second cylinder to allow the compressed gas to be discharged from the second cylinder through the second discharge chamber.   
   
   
       2 . The multi-stage gas compressing apparatus of  claim 1  wherein the first and second gas compressors comprise a booster compressor. 
   
   
       3 . The multi-stage gas compressing apparatus of  claim 1 , further comprising an oilless gas compressor for sending a compressed gas to the first gas compressor. 
   
   
       4 . The multi-stage gas compressing apparatus of  claim 3  further comprising an aftercooler between the first compressor and the second compressor. 
   
   
       5 . The multi-stage gas compressing apparatus of  claim 4  further comprising a drier between the oilless gas compressor and the first booster compressor. 
   
   
       6 . The multi-stage gas compressing apparatus of  claim 5  wherein a compressed gas is taken out of the drier, a compressed gas being taken out of the aftercooler, a compressed gas being taken out of the second gas compressor. 
   
   
       7 . The multi-stage gas compressing apparatus of  claim 6  wherein a compressed gas of less than 1.4 MPa is taken out of the drier, a compressed gas of 1.5 to 2.8 MPa being taken out of the aftercooler, a compressed gas of 2.9 to 3.8 MPa being taken out of the second gas compressor.