MUFFLER AND SCREW COMPRESSOR WITH THE SAME

PROBLEM TO BE SOLVED: To standardize components and to perform muffling or noise reduction with one standardized muffler, with respect to a noise source caused by pulsation over a wide frequency range.SOLUTION: A muffler connected to a compressor outlet interposes in a flow passage in which gas flows, and comprises resonant muffling means and expansive muffling means which are disposed continuously. The resonant muffling means has a double pipe structure and includes a tubular porous inner pipe in which a plurality of through holes are formed in the outer circumference thereof, and an outer pipe forming a resonance space between the outer pipe and the porous inner pipe. The expansive muffling means includes large-diameter piping which forms an expansion space and small-diameter piping which forms a reduction space. At a downstream side of the large-diameter piping, the small-diameter piping is disposed.