Claim 1
Independent Claim
79 words
A method as claimed in claim 1, in which said portion (264'''') expanded to said intermediate pressure, resulting from step (g), is partly vaporized (57), prior to the separation step (h), by heat exchange with said portion (114) separated during step (h) from said gaseous fraction (105), in the course of subcooling (59) prior to its expansion (in valve 4'') according to step (j), and with at least one other flow of fluid (201) in the course of cooling.
Claim 2
Dependent Claim
515 words
An auto-refrigerated cascade installation for cooling and condensing a gaseous mixture (1), comprising a frigorific unit for the circulation of a cycle mixture, said frigorific unit comprising: - a compressor (2) having its suction and delivery operating respectively under a low pressure and a high pressure, comprising a final compression stage (2''), the suction and delivery of which operate respectively at a pressure intermediate said high and low pressures and at said high pressure; - a condenser (3'') for cooling and partial condensation under said high pressure of at least said cycle mixture, the input of said condenser (3'') communicating with the delivery of said compressor (2), and comprising circulation means for an external refrigerant to said frigorific unit; - a first separator (3) for the separation of a first condensed fraction (56) from said cycle mixture partially condensed in said condenser, the inlet of said separator (3) communicating with the outlet of said condenser (3''); - first expansion means (104, 103, 4''), comprising one first expansion valve (4'') for the expansion to said low pressure of at least a portion of said first condensed fraction (56), and the upstream side of which is in communication with the liquid outlet of said first separator (3); - at least one heat exchanger (10) for the fractional condensation under said high pressure of at least the remainder (5) of said cycle mixture, separated from said first condensed fraction (56), and comprising: a first passage means (51) for the cycle mixture (5) in the course of fractional condensation, communicating at one extremity with the gaseous outlet of said first separator (3), and at the other extremity with the inlet (5'') of a second separator (13); a second passage means (52) for the portion of said first condensed fraction (4''''), expanded to said low pressure and in course of vaporization and heating, in heat exchange relation with said first passage means (51), communicating with the downstream side of said first expansion valve (4'') and with the suction of said compressor (2); and a third passage means (53) for said gaseous mixture (1) in the course of cooling and condensation, in heat exchange relation with said second passage means (52); - said first expansion means (104, 103, 4'') being in fluid series and comprising an intermediate stage comprising an intermediate expansion valve (104) for the expansion of said portion (56) of the first condensed fraction from said high pressure to a pressure intermediate said high and low pressures; and - an intermediate separator (103) for the separation of a gaseous fraction (105) from said portion (56) expanded to said intermediate pressure, the inlet of which communicates with the downstream side of said intermediate expansion valve (104), the gaseous outlet (105) of which communicates with the suction of the last compression Stage (2'''') of said compressor (2), so as to combine under said intermediate pressure, said vaporized and heated portion and said gaseous fraction (105) and to recompress them to said high pressure, and the liquid outlet (114) of which communicates with the upstream side of said first expansion valve (4'').
Claim 3
Dependent Claim
165 words
An installation as claimed in claim 3, in which said intermediate stage comprises an intermediate heat exchanger (200) for the partial vaporization of the portion (204'''') of said first fraction expanded (104) to the intermediate pressure, and comprising: a first passage means (57), for said expanded portion (204'''') in the course of vaporization, communicating with the downstream side of said intermediate expansion valve (104) and with the inlet of said intermediate separator (103), a second passage means (59) for the portion (114) expanded to said intermediate pressure and separated from the gaseous fraction (105), in the course of subcooling, in heat exchange relation with said first passage means (57), communicating at one extremity with the liquid outlet (114) of said intermediate separator (103), and at the other extremity with the upstream side of said first expansion valve (4''); and at least a further passage means (60) for another flow (201) in the course of cooling, in heat exchange relation with said first passage means (57).