Liquid-gas separator

Claim 1

Apparatus for separating oil from the mixture of oil and compressed refrigerant gas discharged by an oil-injected compressor in a refrigeration circuit comprising: sealed housing means having a discharge opening and defining an oil sump, said housing means for receiving a mixture of compressed gas into which oil has been injected; a cylindrical, permeable separator shell having an inlet end and an outlet end, said shell being mounted interior of said sealed housing means so that said mixture of oil and gas received by said sealed housing means is communicated directly into the inlet end of said shell and said shell being mounted at a height above said oil sump which precludes contact of said shell with oil in said sump, the permeability of said shell being selected to maintain a predetermined pressure differential between the interior of said shell and the interior of said sealed housing means to facilitate the driving of oil through said permeable shell; means, disposed interior of said shell and including a column coaxial with said shell, for defining a single uninterrupted helical passage having a single helical orientation interior of said separator shell between said inlet end and said outlet end, said column extending less than the entire length of said shell and cooperating with said shell to define an unobstructed discharge area at said outlet end of said shell, said discharge area being in flow communication with said discharge opening of said sealed housing means, whereby in operation a mixture entering said shell is imparted a swirling motion in a single helical direction so that the gas in the mixture travels through said shell in a single swirl and in a single flow direction to minimize the pressure drop in the gas while sufficient centrifugal force is imparted the oil to cause the migration of oil droplets of a size greter than a predetermined size radially outward to and through the permeable wall of said shell within the length of said shell.