(under the class definition) Apparatus including means to conserve heat from gases or vapors exhausted from the apparatus as by heat exchangers, means to use exhaust gases or vapors for heating purposes or the use of exhaust or treating gases or vapors to drive engines.
(1) Note. Mere recirculation of gases or passing gases from chamber to chamber is excluded, being placed with the type of apparatus; see (1) Note to subclass 219 of this class.
SEE OR SEARCH THIS CLASS, SUBCLASS:
62+, for means using gases drawn through a cooler or cooling section
68, for means using exhaust gas in two types of driers.
73+, for means for condensing vapors,
79, for means for burning waste products carried in gases or vapors. 427, and 513+.
SEE OR SEARCH CLASS
60, Power Plants, appropriate subclasses.
165, Heat Exchange,
66, for a combined heating and cooling device that includes a means for exchanging heat between supply and exhaust lines.
201, Distillation: Processes, Thermolytic,
13+, for a carbonizing process including the recovery of heat by indirect heat exchange.
203, Distillation: Processes, Separatory,
21+, for a process of distilling a liquid and recovering heat by indirect heat exchange.
220, Receptacles, and 234, for apparatus wherein the heater causes a gas circulation.
432, Heating, 78+, for a combustion type heater in which combustion air recovers heat from exiting work; subclass 82 for a heater in which entering work recovers heat from exiting work; and subclasses 135+ for a heating chamber in which combustion feed materials recover heat from the chamber exhaust.
