Patent ID: 9671163
Date: 2017-06-06
CPC Classifications: B01D,C10L,F16K,F25J

Claim:
1. An expansion device for an at least partially gaseous fluid, comprising: a tubular inlet portion that is arranged to receive said at least partially gaseous fluid at a predetermined inlet pressure, said tubular inlet portion having an inlet port, an inlet surface consisting of the inner surface of said tubular inlet portion, a longitudinal axis, and a decreasing cross-sectional area, starting from said inlet port; a tubular outlet portion for said at least partially gaseous fluid; a tubular throat portion between said tubular inlet portion and said tubular outlet portion, such that said tubular portions form a passageway for said at least partially gaseous fluid; wherein, in said inlet portion, a central element is arranged to direct said at least partially gaseous fluid according to a flow direction that is generally at an angle with respect to said longitudinal axis, in order to reduce the friction of said at least partially gaseous fluid while flowing through said device, in particular through said throat portion, wherein, downstream of said central element, a closing element is provided in said throat portion, said closing element adapted to cause an expansion with a pressure drop down to a predetermined discharge pressure, a cooling and a partial liquefaction of said at least partially gaseous mixture, said closing element adapted to gradually impart to said fluid a substantially swirling direction that is maintained within an inner recess of the closing element and/or within the outlet portion of the expansion device; wherein, between said central element and said tubular throat portion, a plurality of continuous helical channels is arranged extending from said tubular inlet portion up to said closing element, said helical channels are configured to impart a swirling movement to said at least partially gaseous fluid from said tubular inlet portion up to said closing element, wherein said closing element is a substantially cylindrical hollow body coaxially connected to one end of said central element opposite to said inlet port of said inlet portion, said cylindrical hollow body having a plurality of holes between an outer cylindrical surface and an inner cylindrical surface, wherein said helical channels defined by a plurality of baffles that are arranged according to said flow direction along said annular passage, said baffles having an end portion, and wherein said holes of said closing element have corresponding inlet ports that are arranged at said end portions of said baffles, respectively, in such a way that when a stream portion of said at least partially gaseous fluid leaves said channels at said baffle end portions, said stream portion achieves a swirling direction and directly enters a respective hole of said closing element maintaining said swirling direction both in said holes and in an inner recess of said closing element and in said outlet portion of said expansion device.