Abstract: A falling film evaporator in which some plate elements have their upper portions surrounded by a hood to prevent feed liquor from contacting hot vapor generated in the evaporator and exchanging heat therewith by direct contact. Other elements are located outside the hood.

Abstract: Heating elements formed by joining a pair of plates around most of their peripheries are provided with an internal partition which separates upper and lower internal spaces within the element so that separate streams of condensate are discharged from the element. A plurality of such plate elements can be used in a falling film condenser.

Abstract: In a falling film exchanger, a screen arrangement for preventing solid particles in the liquid to be heated from plugging liquid distribution outlets of a perforated liquid distributing tray or reaching the heating surface of the heat exchanger.

Abstract: A method and apparatus to prevent water hammer and condensation shock in evaporators by closing a vent line when the condensate level rises in an evaporator, thus causing steam flow to the evaporator to stop. The apparatus prevents continuing entry of steam through a steam inlet and thus prevents damage to the evaporator equipment.

Abstract: A method for the recovery of heat and easily evaporable components from hot gases in which a liquid flowing downwards along heat exchanger surfaces is simultaneously heated indirectly, the hot gases are fed into the lower section of a gas space, blast gas containing evaporable components is removed at the upper section of the gas space, and a condensate derived from the hot gases is removed at the bottom of the gas space, comprising further bringing the blast gases into one or several indirect heat exchange contacts with the liquid, in successive additional gas spaces, recovering condensate accumulated at the bottoms of these additional spaces, and withdrawing the blast gases from the last additional gas space.

Abstract: Excess steam pressure is relieved by displacement of a column of water through a vertical conduit opening a path for escape of steam through a space normally occupied by the water which normally acts as a seal. Under reversed conditions, air enters when the water is moved out of its sealing location by vacuum. The pressure vacuum breaker disclosed replaces flapper valves commonly used for pressure relief in paper making applications and has no moving mechanical parts.

Abstract: Contaminant substances having high biochemical oxygen demand, foul odors, etc., are often carried by vapors to be condensed in industrial processes. Certain of these contaminants are more volatile than the primary constituent of the vapor to be condensed. The invention concerns a process and apparatus for separating most of the more volatile contaminants so that separate streams of condensate are produced, one of which is relatively clean while the other stream, though considerably smaller in volume, carries most of the contaminants. A plate type surface condenser having a barrier on the condensing side which prevents the passage of contaminants into a stream of relatively clean condensate is disclosed. In case several different streams of condensate are to be separated, the condenser apparatus has several sections arranged in series.