LN2 Refrigeration Plant
 LHe Refrigeration Plant Helium Recycling System and Helium Purifier Photo Gallery

Liquid Nitrogen Refrigeration Plant

 
Liquid Nitrogen Plant of 5000 W refrigeration capacity at 77 K supplies LN2 to the LHe plant as precoolant and it also cools the thermal shields of the cryostats and the distribution line.The Plant runs either in open loop mode with 50 L/hr production capacity or in close loop mode with enhanced production capacity of 110L/hr by using the cold return gas from the shield through the counter flow heat exchanger.To have sufficient buffer of LN2, there is an external tank of 5000L capacity in addition to the 5000L storage capacity of the plant. Another 20000L of LN2 storage tank is yet to be installed in the yea 2004. All these storage tanks are integrated with the cryostats by vacuum jacketed and super-insulated transfer lines of 140m length.

 
 
Liquid Helium Refrigeration Plant

 
Helium Refrigeration Plant of 600W refrigeration capacity at 4.2K is based on the modified Claude Cycle.It's main components are two screw compressors of 28gm/sec throughput each, LN2 Heat exchanger, two reciprocating expansion engines operating at 60K and 20K respectively and JT valve.The liquefaction capacity is 150L/hr. The plant is integrated with the cryostats of supreconducting Linac by LHe distribution network.

 
 
 
 
Helium Recycling System and Helium Purifier

 
The Helium recycling sytem consists of three pure gas storage tank of water capacity 140M3,two impure gas bag of total 100M3 capacity, two recovery compressors of throughput 20M3/hr each and helium purifier.
A PLC controlled fully automatic Helium Purifier has been designed in-house and integrated with the helium recycling system. The purifier works on the principle of
adsorption by charcoal at 78K. It has the capacity to purify 180M3 helium gas with
1% air inlet impurity.

 
 
 
 
Photo Gallery
1. Air Compressor and the Booster Compressors of LN2 Plant
2. Cryogenerators of the LN2 Plant
3. Cold Box of the LHe plant
4.  Helium Purifier