Abstract: A method of utilizing the high energy values of fossile fuels in central heating boiler systems. The boiler system comprises a processor which includes an air heat pump (5) which functions to cool the system flue gases by condensation. A first fan (10) generates a first circulation (C.sub.1) of boiler room air, via the air heat pump (5), this circulation of air also passing through a heat exchanger (4) where heat exchange takes place with the flue gases. A second air circulation (C.sub.2) is generated with the aid of a flue-gas fan (7) which removes flue gases from the boiler by suction, thereby generating a subpressure in the boiler room so that fresh air will be drawn in from the ambient surroundings, this air passing through the heat exchanger (4). A lower pressure is maintained on that side of the heat exchanger (4) on which the air/flue gas mixture (C.sub.

Abstract: Method for transferring fibrous materials transportable with a liquid between various treatment stages, preferably from digesting (10-16) to a subsequent treatment (38) by means of circuits of circulating liquid. Material from one or several discontinuous treatment steps (10-16) are supplied to a subsequent continuous treatment step the material being fed into the continuous step (38) by displacement by means of a liquid portion (36) withdrawn from the said step.

Abstract: There is disclosed a process for the transfer of fiber material from one circuit of circulating liquid to another, where the fiber material is transported by circuits positioned at right angles to the axis of rotation of a rotary transfer or feed valve and the circulating, transporting liquids are screened off through self-cleaning screens. The transfer valve contains a pocket and three working positions, a filling circuit, an emptying circuit, and an intermediate position for preheating the fiber material or providing a temperature lock depending upon the rotation of the pocket.

Abstract: A process and apparatus for automatically maintaining the moisture content in a continuously conveyed batch of porous materials is described. The porous material is continuously fed through a treatment tank, wherein it is contacted with a liquid to be absorbed therein. The moisture content of the material is continuously monitored as a direct function of the combined weight of the material and the treatment tank to generate correction signals. The correction signals are utilized to vary the dwell times (up or down) of the porous material in the treatment tank. By varying the dwell times the porous material is contacted by the treating liquid for either larger or shorter periods until the weight of the tank and material therein returns to the weight desired. Thus, the moisture content of the porous material is continuously adjusted to a substantially constant value.