Abstract: The present invention produces a cold gas stream having a constant temperature and pressure. The gas stream is obtained from two initial streams, one being a liquefied gas and the other being a gas at ambient temperature. The liquefied gas stream is combined with the warm gas stream, causing the liquid to vaporize. The two streams are combined in proportions that yield a cold gas mixture having a desired temperature. The resulting cold gas mixture is directed into an insulated container having a volume significantly larger than the volume of the conduits through which the streams flow. The container therefore acts as a buffer to reduce pressure fluctuations in the stream. A temperature equalization coil is located in the interior of the container. The coil has one open end which communicates with the interior region of the container, the other end of the coil being connected to an outlet line.

Abstract: A vacuum furnace is cooled in a two-step process. In the first step, a noble gas is injected into the furnace to break the vacuum, and to provide initial cooling. In the second step, a non-noble, but relatively inert, gas is injected into the furnace to complete the cooling. The flow of the noble gas is cut off when the temperature in the furnace falls below the point at which the contents of the furnace will no longer react with the second gas. The invention also discloses apparatus for cooling the furnace. Temperature controllers monitor the temperature, and rate of temperature change, in the furnace, and direct controlled amounts of noble or non-noble gas into the furnace. At no time is a liquefied gas allowed to enter the furnace. The process allows the furnace to be cooled rapidly but safely, minimizing the danger of thermal shock to the internal furnace components.

Abstract: A vacuum furnace is cooled in a two-step process. In the first step, a noble gas is injected into the furnace to break the vacuum, and to provide initial cooling. In the second step, a non-noble, but relatively inert, gas is injected into the furnace to complete the cooling. The flow of the noble gas is cut off when the temperature in the furnace falls below the point at which the contents of the furnace will no longer react with the second gas. The invention also discloses apparatus for cooling the furnace. Temperature controllers monitor the temperature, and rate of temperature change, in the furnace, and direct controlled amounts of noble or non-noble gas into the furnace. At no time is a liquefied gas allowed to enter the furnace. The process allows the furnace to be cooled rapidly but safely, minimizing the danger of thermal shock to the internal furnace components.