Circulation-type liquid helium reliquefaction apparatus with contaminant discharge function, method of discharging contaminant from the apparatus, and refiner and transfer tube both of which are used for the apparatus

A contaminant-purging method for the circulation type liquid helium recondensation device that is employed in the liquid helium recondensation procedure comprising the operating steps of pumping helium gas evaporating from a liquid helium storage tank using a circulating pump, refining the pumped helium gas in a refiner, liquefying the gas, and returning the liquefied helium to the liquid helium storage tank for recycling, in which said refiner is heated to vaporize contaminants deposited on the refiner, and the vaporized contaminants are discharged to the atmosphere.

A contaminant-purging method for the circulation type liquid helium recondensation device that is employed in the liquid helium recondensation procedure comprising the operating steps of pumping helium gas evaporating from a liquid helium storage tank using a circulating pump, refining the pumped helium gas in a refiner, liquefying the gas, storing the liquefied helium in a condensing pot, and transferring the liquid helium from said condensing pot to the liquid helium storage tank for recycling, in which at least either of said condensing pot or said refiner is heated to vaporize the contaminants deposited on the refiner, and the vaporized contaminants are discharged to the atmosphere.

A refiner for the circulation type liquid helium recondensation device with a contaminant-purging function designed to pump helium gas evaporating from a liquid helium storage tank using a circulating pump, refine the pumped helium gas in the refiner, liquefy the gas, and return the liquefied helium to the liquid helium storage tank for recycling, in which said refiner is made up of a thermally conductive housing, with contaminant solidification unit installed on the housing, an infeed means to transfer helium gas to said housing, and a heating means to vaporize the contaminants attached to said solidification unit, and in which the contaminants vaporizing in the refiner are discharged from the refiner to the atmosphere via said infeed means.

A transfer tube for a circulation type liquid helium recondensation device designed to pump helium gas evaporating from a liquid helium storage tank using a circulating pump, refine the pumped helium gas in a refiner, liquefy the gas, and return the liquefied helium to the liquid helium storage tank for recycling, in which said transfer tube comprises a central tube for flowing liquid helium at about 4K (near-4KL) at the center, a second tube for flowing liquid helium gas at about 4K (near-4KG) coaxially arrayed outside the central tube, and a third tube for flowing liquid helium gas at about 40K coaxially arrayed outside the second tube, and in which a vacuum insulation layer is formed between adjacent tubes and outside the third tube.