Design and Construction of Nitrogen Liquefier

Abstract

The design and construction of nitrogen liquefier begins with the process design of the cycle. The simulation of the cycles has been done using the software Aspen HYSYS. The compressor unit is available in the laboratory. Two number of high effectiveness, vacuum brazed aluminum plate fin heat exchangers are designed and fabricated. Turboexpander is designed and all of its components are fabricated. A suitable modification has been done with a precession needle valve to operate as a long stem JT valve. For separating the liquid, a phase separator is designed and fabricated. All the components are assembled inside a double walled cold box with pipes as per the process need. The necessary pressure, temperatureand other measuring instruments, valves and safety devices are mounted on the liquefier. After successful running of the liquefier, for the mass flow rate of 296 kg/hr for gaseous nitrogen, it is expected to deliver 17.44 lit/hr of liquid nitrogen.