Noise reduction using suction gas to foam oil

Abstract

A first portion of a pitot tube-like device faces into the incoming stream of suction gas which enters the hermetic shell of a low-side reciprocating compressor. A second portion of the device extends downwardly toward the oil sump within the shell. The device terminates in a third portion which defines a plurality of apertures and which is immersed in the oil within the sump. The dynamic pressure or velocity head of the incoming suction gas stream is converted within the device to static pressure as a result of the resistance to flow through the device. The resistance to flow through the device is a function of, among other things, the static head at the immersed aperture locations. The device is configured such that sufficient static pressure is developed internal of it to both drive any oil out of the submerged portion of the device at compressor startup and to maintain a steady, predetermined rate of flow of suction gas through the immersed apertures into the sump oil during steady state compressor operation. Suction gas entering the sump oil at the immersed aperture locations bubbles to the surface of the oil in the sump where the bubbles coalesce to form a noise attenuating blanket of foam around the motorcompressor unit within the shell.

Dependencies are inferred from the claim text.