A nonpressurized insulated container that has a vacuum space between the outer shell and inner vessel is known as what?

A nonpressurized insulated container that has a vacuum space between the outer shell and inner vessel is known as what?

• A. Dewar flask
• B. Carboy
• C. Cylinder
• D. Tank

Answer: (A)

A Dewar flask is a double-walled, vacuum-insulated container used to store cryogenic liquids. The vacuum space between the outer shell and the inner vessel minimizes heat transfer by eliminating convection and significantly reducing conduction, while reflective inner surfaces minimize radiant heat gain. This design keeps the contents extremely cold with very little boil-off and is intended to be nonpressurized. In contrast, a carboy is just a basic bottle without insulation, and cylinders or tanks are typically pressure vessels rather than vacuum-insulated storage.

A Dewar flask is a double-walled, vacuum-insulated container used to store cryogenic liquids. The vacuum space between the outer shell and the inner vessel minimizes heat transfer by eliminating convection and significantly reducing conduction, while reflective inner surfaces minimize radiant heat gain. This design keeps the contents extremely cold with very little boil-off and is intended to be nonpressurized. In contrast, a carboy is just a basic bottle without insulation, and cylinders or tanks are typically pressure vessels rather than vacuum-insulated storage.