Patent ID: 9441877
Filing Date: 2016-09-13
CPC Classification: F25J

Claim Text:
1. A system for cooling a gas with a mixed refrigerant including: a) a heat exchanger including a warm end and a cold end, the warm end having a feed gas inlet adapted to receive a feed of the gas and the cold end having a product outlet through which product exits said heat exchanger, said heat exchanger also including a cooling passage in communication with the feed gas inlet and the product outlet, a pre-cool liquid passage, a pre-cool refrigeration passage, a high pressure passage and a primary refrigeration passage, said pre-cool refrigeration passage passing solely through the warm end of the heat exchanger and said primary refrigeration passage passing through both the cold end and the warm end of the heat exchanger; b) a suction separation device having a vapor outlet and a liquid outlet; c) a first stage compressor having a suction inlet in fluid communication with the vapor outlet of the suction separation device and an outlet; d) a first stage after-cooler having an inlet in fluid communication with the outlet of the first stage compressor and an outlet; e) an interstage separation device having an inlet in fluid communication with the outlet of the first stage after-cooler and having a vapor outlet exclusively in fluid communication with the primary refrigeration passage of the heat exchanger so that the primary refrigeration passage of the heat exchanger receives fluid solely from the vapor outlet of the interstage separation device and a liquid outlet exclusively in fluid communication with the pre-cool liquid passage of the heat exchanger so that the pre-cool refrigeration passage of the heat exchanger receives fluid solely from the liquid outlet of the interstage separation device; f) a first expansion device having an inlet in fluid communication with the pre-cool liquid passage of the heat exchanger and an outlet in communication with the pre-cool refrigeration passage of the heat exchanger; g) a second expansion device having an inlet in fluid communication with the high pressure passage of the heat exchanger and an outlet in communication with the primary refrigeration passage of the heat exchanger; h) said pre-cool refrigeration passage adapted to produce a mixed phase outlet stream that exits the pre-cool refrigeration passage through a pre-cool refrigeration passage outlet and said primary refrigeration passage adapted to produce a superheated vapor outlet stream that exits the primary refrigeration passage through a primary refrigeration passage outlet; and i) a return fluid handling circuit including a junction in communication with the pre-cool refrigeration passage outlet and the primary refrigeration passage outlet, said junction configured to combine the mixed phase outlet stream and the superheated vapor outlet stream prior to the suction inlet of the first stage compressor; j) said suction separation device also in fluid communication with an outlet of the primary refrigeration passage of the heat exchanger so as to receive the superheated vapor stream directly without passing through a compressor; and k) a pump having an inlet in fluid communication with the liquid outlet of the suction separation device and an outlet in fluid communication with the interstage separation device.