This class relates to heating liquids, generating vapors fromliquids, treating the vapors generated for use, such as superheatingor cooling them, and conserving the heat remaining in the liquidor vapor after a part of the heat energy has been made use of forany purpose. To bring a liquid heater into this class, the chamber,receptacle or conduit in which the liquid is heated must be fluidtight.
This class includes combinations of steam superheaters, feed-waterheaters, steam separators, condensers, traps, manhole-closures,safety devices, cleaners, and feeders with a boiler when the structureof necessity must form a part of the boiler structure combination,also parts of boilers unless they are of general application.
This class includes water-cooled grates whether or not inconnection with a boiler for heating the boiler water. It alsoincludes the boiler and furnace in combination or the boiler alonewith the furnace alone.
The liquid containers classified in this class may be heatedby solid or fluid fuel burned in any type of furnace or burner,by friction, or by chemical action other than combustion, or byelectricity. The heat may be applied directly to the walls of thefluid containing chamber or indirectly by the interposition of afluid in a distinct and separate chamber, which fluid being heated mayimpart its heat to the fluid to be finally heated. When the fluidis heated by the interposition of another fluid the heat generatormust be a part of the unitary structure of the fluid heater, withone exception--to wit: devices for generating a vapor having a vaporseparator within the fluid chamber may be heated indirectly by a fluid,the furnace for heating which does not form part of the unitarystructure. The fluid may be heated also by a heat radiating bodyin either a liquid, or solid state, which body may be either onthe inside or on the outside of the fluid chamber; but if said heatingbody be inside the fluid chamber its nature must be such that itwill not mix with the fluid to be heated.