초록 ▼

An apparatus and method for regulating the temperature in a cryogenic test chamber. Liquid helium is drawn into a test chamber located in a cryogenic vessel through a capillary tube which is spaced apart from the test chamber. The capillary tube is thermally insulated from the liquid helium. In a hi

An apparatus and method for regulating the temperature in a cryogenic test chamber. Liquid helium is drawn into a test chamber located in a cryogenic vessel through a capillary tube which is spaced apart from the test chamber. The capillary tube is thermally insulated from the liquid helium. In a high temperature mode, a heater element heats the capillary tube to a temperature just high enough to boil the liquid helium as the helium is drawn through the capillary tube into the test chamber, thereby insuring that only gaseous helium enters the test chamber and preventing any tendency of the temperature in the test chamber to oscillate when the test chamber is warmed to temperature only slightly higher than the temperature of the liquid helium. In a low temperature mode the heater element heats the capillary tube sufficiently to substantially prevent any helium from flowing into the test chamber, thereby facilitating cooling of the test chamber to temperature below the temperature of the liquid helium by evacuating the test chamber until the liquid therein boils at the desired temperature.

대표청구항 ▼

Temperature regulation apparatus comprising: a cryogenic vessel adapted to contain a fluid in a liquid phase at a cryogenic temperature; a capillary tube located in the cryogenic vessel; capillary heater means in thermal communication with the capillary tube; means defining a test chamber in the cry

Temperature regulation apparatus comprising: a cryogenic vessel adapted to contain a fluid in a liquid phase at a cryogenic temperature; a capillary tube located in the cryogenic vessel; capillary heater means in thermal communication with the capillary tube; means defining a test chamber in the cryogenic vessel in spaced-apart relation to the capillary tube; fluid flow means defining a fluid flow path between the capillary tube and the test chamber; test chamber heater means in thermal communication with the test chamber; and evacuation means operative to partially evacuate the test chamber to draw fluid from the cryogenic vessel through the capillary tube and the fluid flow means into the test chamber, the apparatus being operative to regulate the temperature in the test chamber by maintaining the fluid therein at a desired temperature and operable in a high temperature mode wherein the capillary heater means is operative to warm the capillary tube sufficiently to boil any liquid flowing therein and thereby to change the phase of the fluid from liquid to gas as the fluid is drawn through the capillary tube into the test chamber and wherein the test chamber heater means is operative to warm any gas in the test chamber to a desired temperature and thereafter to maintain the gas at said temperature, operable in a medium temperature mode wherein the fluid remains in its liquid phase without undergoing any net change in temperature as it is drawn through the capillary tube into the test chamber and is thereby maintained at the cryogenic temperature in the test chamber, and operable in a low temperature mode wherein the fluid remains in its liquid phase as it is drawn through the capillary tube into the test chamber until a reservoir of liquid has accumulated in the test chamber, the capillary heater means thereupon being operative to warm the capillary tube sufficiently to substantially prevent the flow of any more fluid through the capillary tube, and the evacuation means thereupon being operative to reduce the pressure in the test chamber sufficiently to lower the boiling temperature of the liquid in the chamber to a desired temperature and thereafter to evacuate any gas produced as the liquid boils and thereby to maintain the liquid at said temperature.