JT Sorption Type Cryocooler Operation of a sorption

JT Sorption Type Cryocooler Operation of a sorption compressor is based on the principle that large amounts of gas can be adsorbed on certain solids such as highly porous carbon. The amount of gas adsorbed is a function of temperature and pressure.

JT Sorption Type Cryocooler Physical and Chemical effects on surface Absorption is a Chemical phenomenon or a process in which atoms, molecules, or ions enter some bulk phase. Adsorption is the adhesion of molecules of gas, liquid, or dissolved solids to a surface. This is physical effect. Adsorption

JT Sorption Type Cryocooler Typical gas - sorber combinations for sorption cryocoolers

JT Sorption Type Cryocooler Working of Sorption Type Cryocooler • By nature, a sorption compressor element is an intermittent system in which the sorbent bed alternates between gas generation and adsorption. • By combining at least two sorbent beds in a single compressor and sequencing these sorbent beds out of phase, it is possible to produce a constant flow of gas through the cold stage and thus achieve continuous refrigeration.

JT Sorption Type Cryocooler

JT Sorption Type Cryocooler Working of Sorption Type Cryocooler • • a) b) c) d) The compressor unit contains four sorption cells and two check valves fitted to each cell for controlling control the gas flows. Sorption compressor type J-T cryocooler essentially consists of Sorption type compressor After cooler Return gas heat exchanger J-T expansion device

JT Sorption Type Cryocooler Working of Sorption Type Cryocooler • Usually, heating occurs with an electrical heater and cooling is done by circulating water in a coil around the sorption cell

JT Sorption Type Cryocooler Valve position in JT cryocooler

JT Sorption Type Cryocooler Working of Sorption Type Cryocooler • • The working fluid is initially heated in the Cell A for ¼ cycle. Inlet Valve of A and Outlet Valve of C are opened. The hot working fluid is cooled to room temperature in the after cooler. The high pressure working fluid at room temperature enters the recuperative heat exchanger, where, it is cooled by the return gas. The working fluid is then expanded Isenthalpically by passing through a J-T Valve. Resulting in reduction of temperature. The low temperature working substance evaporates as it takes the heating load and produces refrigeration. The working substance then enters the return gas heat exchange before getting adsorbed into the Cell C A B C D

JT Sorption Type Cryocooler • The type of compression employed in sorption compressor cell is – Reciprocating type – Rotary Compressor – Adsorption type – None of the above

JT Sorption Type Cryocooler • Pressure is developed due to – Adsorption – Absorption – Desorption – Sorption

JT Sorption Type Cryocooler • Heat exchanger prior to JT valve is used to – Reduce the temperature before expansion – To increase the cop – To remove gaseous heat – For refrigeration effect

JT Sorption Type Cryocooler • Adsorption is a ____? – Physical effect – Chemical effect – mostly physical , but in certain cases it is chemical – Neither physical nor chemical process

JT Sorption Type Cryocooler • Desorption in a cell comprises of ____? – Compression – Expansion – Combined compression and expansion – Refrigeration

JT Sorption Type Cryocooler Cryogenic Engineering By R Barrons http: //www. cryomech. com/ http: //www. che. cemr. wvu. edu/publications/projects /large_proj/air. PDF