A Liquid Helium (LHe) Dewar is a critical component of any helium liquefaction system. LHe Dewar is a double walled vessel & LHe is stored in the inner vessel. A Liquid Helium (LHe) Dewar of 1000 L nominal capacity having a net evaporation rate (NER) of ≈ 1% per day. Because of very low latent heat of LHe, control of heat in-leak into LHe is very critical, in 1000L LHe Dewar allowable heat in-leak to LHe by all mean (Conduction, Convection and Radiation) is just 0.3 watts. High leak tight and special arrangements are required for long term vacuum retention of the Dewar. Liquid Helium (LHe) Dewar is used in various helium liquefaction systems for storage and distribution of LHe.

 SPECIFICATIONS

A Liquid Helium (LHe) Dewar is a critical component of any helium liquefaction system. LHe Dewar is a double walled vessel & LHe is stored in the inner vessel. A Liquid Helium (LHe) Dewar of 1000 L nominal capacity having a net evaporation rate (NER) of ≈ 1% per day. Because of very low latent heat of LHe, control of heat in-leak into LHe is very critical, in 1000L LHe Dewar allowable heat in-leak to LHe by all mean (Conduction, Convection and Radiation) is just 0.3 watts. High leak tight and special arrangements are required for long term vacuum retention of the Dewar.

APPLICATIONS

• Liquid Helium (LHe) Dewar is used in various helium liquefaction systems for storage and distribution of LHe. LHe is required to cool superconducting magnets, super conducting RF cavities, etc.

ADVANTAGES

• Liquid Helium (LHe) Dewar having low net evaporation rate (NER) ≈ 1% per day.

WORKING PRINCIPLE

A liquid helium (LHe) receiver vessel is a double walled vessel. LHe is stored in the inner vessel. Annular space between the outer and inner vessels is maintained under high vacuum due to initial evacuation and cryo-pumping at cold conditions. Multilayer super insulation and thermal shields are used between the inner and outer vessels. It is used in helium liquefaction systems for storage and distribution of LHe.

SPECIFICATIONS

INFRASTRUCTURE REQUIRED

• SS pressure vessel manufacturing facilities with high bay area and overhead crane.
• TIG welding and SS-Cu brazing facilities.
• MSLD facility.
• Super-insulation wrapping facility inside a moisture free clean room, expertise of manufacturing cryogenic pressure vessels/ pipings.
• 1000 square feet space is required for assembly, testing & installation of the LHe Dewar.

MATERIAL AVAILABILITY

• Most of the components are available within the country and some components need to be imported through local agents.

MANPOWER

• A mechanical engineer & 2 trained technicians will be required for the development of this Liquid Helium (LHe) Dewar.