Cryogenic processes liquid level

Cryogenic processes using turboexpanders facilitate high levels of ethylene recovery from refinery gas while producing byproducts of hydrogen- and methane-rich gas. In a cryogenic process, most of the ethylene and almost all of the heavier components are liquified and ethylene is separated from this liquid. 

Modern cryogenics plants are well-instrumented to indicate process temperatures and pressures, flow rates, liquid levels, and contaminant concentrations. These instruments are used for measurement, control, and safety if a particular variable (temperature, pressure, flow rate) falls outside the control range, a corrective action is initiated automatically and, if necessary, an alarm may also be actuated. Complete alarm systems are now available commercially for use with all the common safety devices. Further, many are designed on the failsafe principle and sound an alarm in the event a power failure occurs. 

The most important level detection tasks in the renewable energy processes include cryogenic (H2) and boiling applications, where vapor bubbles are present in the liquid (steam boilers). About two dozen different types of... 

In modern DHS instrumentation the two-stage thermal desorption process consists of tube desorption onto a Peltier-cooled trap, followed by trap desorption of the heated trap. Peltier-cooled focusing traps concentrate volatile organics without liquid cryogen. Rapid thermal desorption of the focusing trap (40°C/s) produces component bands about 1 s wide for uncompromised narrow-bore CGC. Flexible split-ratio selection facilitates a wide range of applications from trace level to percent levels of... 

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