PURPOSE: To uniformly and rapidly cool a large quantity of tubes with a compact tank capacity by supporting the plural tubes in an upright state on a framed truck, charging the tubes into a refrigeration chamber, blowing liquid nitrogen out of the lower part of this refrigeration chamber, sucking up gas from the upper part and circulating the gas to the lower part.
CONSTITUTION: The tubes which are works are supported in the upright state on the truck 3 having a vertical frame 6 and are loaded into a refrigeration device 1. The liquid nitrogen is discharged from nozzles 26 disposed in the lower part of the refrigeration device 1. A blower disposed in the ceiling part of the refrigeration device sucks up the gas from the upper part and circulates the gas to the lower part. The water in the tubes which are the works freezes from below to above or from outside to inside and, therefore, the change of the tubes by bulging does not arise. The works are carried out of the refrigeration device 1 together with the truck and the subjected to bending after completion of the refrigeration.
KARASAWA TAKAO
NAKAYAMA MINEO
SHIMURA HIROSHI
SANKEI GIKEN KOGYO KK
SANYO DENYOSHA KK