Abstract: An arrangement for utilizing the heat contained in the exhaust gas from a coal-fired boiler for preheating feed water for the boiler and for preheating primary air. The arrangement includes a rotating heat transfer unit and lines for conducting exhaust gas and preheated combustion air to the heat transfer unit. A heat shifting unit is connected in parallel to the heat transfer unit. A line conducts primary air to the heat shifting unit and another line conducts cooled exhaust gas from the heat transfer unit to the heat shifting unit. The exhaust gas line and the cooled exhaust gas line connecting the heat transfer unit and the heat shifting unit are connected through a bypass which bridges the heat transfer unit. The bypass includes a heat exchanger and/or steam generator, wherein the boiler feed water flows through the heat exchanger and/or steam generator.

Abstract: A method and an apparatus for the denitrification and desulfurization of hot waste gases, particularly from furnaces. A crude gas flow is initially conducted through a denitrification plant and through the endothermic part of a heat-utilizing plant. Subsequently, the flow is conducted into a desulfurization plant. The purified gas flow discharged from the desulfurization plant is conducted through the exothermic part of the heat-utilizing plant and is subsequently transferred to ambient. By means of a cooling trap, a portion of the heat contained in the crude gas flow before the contact with the heat-utilizing plant is removed while precipitating sulfuric acid in the form of vapor, and this heat is then added to the purified gas flow before the contact thereof with the heat-utilizing plant.

Abstract: An arrangement for the catalytic oxidation of the harmful components in a cooled carrier gas from a technical process. The arrangement includes two parallel gas ducts which are connected at one end through a bend and whose other ends are connected to gas lines for the carrier gas and for purified gas. The gas ducts are connected to each other through a three-stage thermal energy return unit. The exchanger stage of the thermal energy return units are arranged spaced from each other and are composed of individual heat tubes whose number increases from exchanger stage to exchanger stage. The size ratio of the heat-exchanging surfaces of heating part to cooling part of each exchanger stage decreases in flow direction of the carrier gas from exchanger stage to exchanger stage. The catalyst is integrated in the gas duct for the carrier gas immediately downstream of the heating part of the last exchanger stage.

Abstract: Essentially triangular turbulators 3 extending at an angle .alpha. to the tube longitudinal plane RLE running through the tube axis RA as well as parallel to the fluid flow direction FSR are arranged on the flat lateral ribs 2 of a heat exchanger tube 1. The turbulators 3 are stamped out of the rib plane and are then bent off at an angle of approximately 90.degree.. They have flash or parting lines 4 rising in the fluid flow direction FSR as well as in the direction of the heat exchanger tube 1. This allows generation of longitudinal vortices 5 downstream of the turbulators 3 which roll over the boundary layers in this location and improve the heat transfer.

Abstract: In an air-cooled surface condensor including a plurality of elongated finned heat exchanger tubes arranged in a single row, each tube has a continually increasing cross-sectional area from a front end to a rear end of the tube in the direction of flowing of cooling air. A separating wall provided with perforations is mounted within each tube.

Abstract: In finned tube arrangements for cooling a medium which flows in the finned tubes by a second medium which flows outside of the finned tubes and transversely thereof, flow guide elements are positioned at the inflow side and/or at the outflow side of the finned tube arrangement to reduce the pressure loss and, possibly, increase the heat transfer coefficient.

Abstract: In a wet type or wet/dry type cooling tower, water discharged from water distributing means after its passage cooling air heat exchanger is intercepted by an array of parallel water guiding plates. Each guiding plate has a sloping upper part which covers the gap between opposite plates and an upright lower part defining a substantially horizontal transition region with the upper part. A plurality of inclined channel like embossments is formed in the upright lower part. The embossments extend one above the other between a lateral edge of the upright lower part and the transition region. At least one water collecting channel extends in transverse direction along the lateral edges of the upright lower part to collect water discharged from the inclined embossments and transfer the collected water to a recirculation device.

Abstract: In order to obtain the requisite chimney temperature of cleaned gas discharged from a desulfurizing installation, and in order to avoid problems resulting at temperatures below the dew point of sulfuric acid in heat exchangers made of steel, the invention provides the following measures: the heat exchange between the crude gas stream and the cleaned gas stream is made in a first stage including conventional heat exchangers made of steel. An additional stage of heat exchangers between the crude and cleaned gas streams is constructed of corrosion-resistant and adhesion inhibiting plastic material and operating in a lower temperature range. Transfer conduits of corrosion-resistant material connect the lower temperature heat exchangers to forcibly transfer a heat carrying fluid.