Abstract: A carbottom furnace is described as having high velocity or high momentum-type stoichiometric burners, rather than excess air-type burners. Hot exhaust gas, removed from the furnace, is recirculated immediately back to the heat treatment chamber of the furnace, without reheating, in a manner which compliments and reinforces the swirling flow of gas created in the chamber by the high momentum burners. This recirculation of exhaust gas is especially useful during normal turndown of the burners to maintain sufficient volume of heated gas within the chamber to properly heat treat the articles or workpieces which are positioned within the chamber.

Abstract: The present invention is an apparatus and method for cooling heat exchanger tubes at controlled conditions. The apparatus comprises a housing sealingly connected to each heat exchanger tube. There are water and air inlets to the housing. A means to generate mist is located within the housing and directed to spray a jet of mist from the housing into the heat exchanger tube. During operation, air is injected into each heat exchanger tube at controlled conditions. The air is followed by a water mist under controlled flow conditions into each tube. Carrier air accompanies the water mist. A controlled flow of water is injected into each heat exchanger tube after the water mist.

Abstract: The present invention is an improved apparatus and method for directly heat treating articles in a sealed treatment chamber of the heat treatment furnace. A burner means fires into a precombustion chamber which is connected in communication with the treatment chamber. Combustion is completed in the precombustion chamber and the products of combustion are fed into the treatment chamber. Additional treatment gas such as an endothermic gas is fed directly into the furnace treatment chamber.

Abstract: The present invention is an apparatus and method for cooling heat exchanger tubes at controlled conditions. The apparatus comprises a housing sealingly connected to each heat exchanger tube. There are water and air inlets to the housing. A means to generate mist is located within the housing and directed to spray a jet of mist from the housing into the heat exchanger tube. During operation, air is injected into each heat exchanger tube at controlled conditions. The air is followed by a water mist under controlled flow conditions into each tube. Carrier air accompanies the water mist. A controlled flow of water is injected into each heat exchanger tube after the water mist.

Abstract: The present invention is an apparatus and method for cooling heat exchanger tubes at controlled conditions. The apparatus comprises a housing sealingly connected to each heat exchanger tube. There are water and air inlets to the housing. A means to generate mist is located within the housing and directed to spray a jet of mist from the housing into the heat exchanger tube. During operation, air is injected into each heat exchanger tube at controlled conditions. The air is followed by a water mist under controlled flow conditions into each tube. Carrier air accompanies the water mist. A controlled flow of water is injected into each heat exchanger tube after the water mist.

Abstract: The present invention is an apparatus and method for cooling heat exchanger tubes at controlled conditions. The apparatus comprises a housing sealingly connected to each heat exchanger tube. There are water and air inlets to the housing. A means to generate mist is located within the housing and directed to spray a jet of mist from the housing into the heat exchanger tube. During operation, air is injected into each heat exchanger tube at controlled conditions. The air is followed by a water mist under controlled flow conditions into each tube. Carrier air accompanies the water mist. A controlled flow of water is injected into each heat exchanger tube after the water mist.