Exhaust vent for cooling rigs transported on vehicles

Claim 1

In an exhaust vent for cooling rigs transported on vehicles, the interior of which is cooled by the introduction of a low boiling liquified gas, the improvement being a plurality of inserts mounted at the exhaust vent to comprise means which force the outflowing gas to be deflected several times, said inserts comprising parallel sheet metal plates between which the gas flows in a meandering fashion, at least some of said parallel plates being perforated, said perforations in said plates being staggered to force the gas exhausting therethrough to flow in a labyrynth path, said parallel plates including an intermediate plate which is perforated, said vent having a peripheral inner wall, said perforated intermediate plate extending to said peripheral inner wall of said vent whereby all exhaust gas must flow through its perforation, said plates further including a plate on one side of said intermediate plate which is not perforated and is spaced from said inner wall of said vent whereby the gas flows therearound, and said plates including a plate on the other side of said intermediate plate which is perforated and is spaced from said inner wall of said vent whereby the gas flows therearound and therethrough.