Abstract: The invention relates to a regenerative thermal postcombustion plant (24) used for purifying exhaust gas comprising hydrocarbons and nitrogen oxides, particularly for exhaust gas occurring during cement clinker production, by means of which the carbon compound is oxidized and the nitrogen oxides are thermally reduced while feeding in a nitrogen-hydrogen compound at a temperature of greater than 800° C. in the multistage combustion chamber (35).

Abstract: A device for the purification of polluted waste gas by means of regenerative thermal oxidation. The device has at least two heat-accumulator towers having a common combustion chamber and each containing a heat-accumulator material, the upper ends of which face the combustion chamber. The heat-accumulator towers are each connected via a control chamber to a channel for the supply of the raw gas to be purified and a channel for the discharge of clean gas. The two channels are each connectable to the at least two heat-accumulator towers via the control chambers for an alternating supply of raw gas and discharge of clean gas via shut-off devices actuable by actuators. The two channels are arranged laterally adjacent to the heat-accumulator towers and are located adjacent each other and above the respective control chambers and interconnected with the respective control chambers through openings therebetween, with the openings being closable via shut-off devices.

Abstract: The invention relates to a regenerative thermal postcombustion plant (24) used for purifying exhaust gas comprising hydrocarbons and nitrogen oxides, particularly for exhaust gas occurring during cement clinker production, by means of which the carbon compound is oxidized and the nitrogen oxides are thermally reduced while feeding in a nitrogen-hydrogen compound at a temperature of greater than 800° C. in the multistage combustion chamber (35).

Abstract: A device for the purification of polluted waste gas by means of regenerative thermal oxidation. The device has at least two heat-accumulator towers having a common combustion chamber and each containing a heat-accumulator material, the upper ends of which face the combustion chamber. The heat-accumulator towers are each connected via a control chamber to a channel for the supply of the raw gas to be purified and a channel for the discharge of clean gas. The two channels are each connectable to the at least two heat-accumulator towers via the control chambers for an alternating supply of raw gas and discharge of clean gas via shut-off devices actuable by actuators. The two channels are arranged laterally adjacent to the heat-accumulator towers and are provided on the side opposite to the control chambers with said openings being closable via shut-off devices.

Abstract: For treating waste gas flows, a regenerative thermal afterburning system is used, comprising at least four regenerators, filled with ceramic heat accumulator bodies, and connected via a common combustion chamber. The waste gas is alternately admitted in cycles to one regenerator, whose heat accumulation bodies have been preheated, and then burned in the combustion chamber to yield clean gas, the said gas being extracted by a further regenerator, with simultaneous heating of the latter's heat accumulator bodies, while a third regenerator is flushed with flush gas. During the cyclical operation of the three regenerators, the remaining fourth regenerator extracts combustion chamber air from the combustion chamber, for the removal of deposits on the heat accumulator bodies in this regenerator by means of pyrolysis. In turn, a fan then feeds this extracted air to the crude gas.

Abstract: For treating waste gas flows, a regenerative thermal afterburning system (I) is used, comprising at least four regenerators (1, 2 3, 4), filled with ceramic heat accumulator bodies, and connected via a common combustion chamber (5). The waste gas is alternately admitted in cycles to one regenerator (1, 2, 3, 4), whose heat accumulation bodies have been preheated, and then burned in the combustion chamber (5) to yield clean gas, the said gas being extracted by a further regenerator (1, 2, 3, 4), with simultaneous heating of the latter's heat accumulator bodies, while a third regenerator (1, 2, 3, 4) is flushed with flush gas. During the cyclical operation of the three regenerators (1, 2, 3, 4), the remaining fourth regenerator (1, 2, 3, 4) extracts combustion chamber air from the combustion chamber (5), for the removal of deposits on the heat accumulator bodies in this regenerator (1, 2, 3, 4) by means of pyrolysis. In turn, a fan (17) then feeds this extracted air to the crude gas.

Abstract: An apparatus for cleaning pollutant-laden waste gas by regenerative thermal afterburning has two towers (1, 2) each divided into three heat-retaining chambers (14 to 16 and 17 to 19) by vertical partitions (10 to 13). Two opposite heat-retaining chambers (14 to 16 and 17 to 19) of the towers (1, 2) are connected by one switching chamber (26, 27, 28) in each case, said chambers being disposed between a loaded gas supply channel (29) and a clean gas removal channel (23). For alternately supplying loaded gas to two opposite heat-retaining chambers of the towers and removing clean gas from two other opposite heat-retaining chambers of the towers, each switching chamber (26, 27, 28) is adapted to be connected alternatively with the loaded gas supply channel (29) and the clean gas removal channel (23) by shut-off devices (50, 52, 53) operated with a control unit.

Abstract: For cleaning waste air loaded with organic pollutants one uses an adsorptive cleaning plant with a rotating cylindrical body containing an adsorbent through which waste air to be cleaned is passed for adsorption of the pollutants, hot air for desorption of the adsorbed pollutants and cooling air for cooling the desorption zone. Waste air with desorbed pollutants is supplied to an afterburning plant with a firebox. The hot air is formed by mixture of a part of the firebox air heated to 700 to 900.degree. C. produced in the firebox, with the heated cooling air passing out of the cylindrical body. The afterburning plant has two chambers connected via the firebox and filled with a heat-retaining packing, waste air with desorbed pollutants being supplied alternatingly to one of the chambers and clean air removed from the other chamber.

Abstract: The invention relates to a method for the automatic and energy-saving dedusting of organic deposits on heat exchangers of regenerative afterburning systems without secondary emissions. Through a special guiding of the exhaust gas, the partial exhaust-air stream is returned without interruption of the main exhaust gas stream from the tower to be burnt off completely into the crude gas (FIG. 1). With this, the entire system is returned without any additional operations again into the original clean initial state and the burdening of the atmosphere is avoided.

Abstract: A method of recovering or extracting chemicals, such as furfural, formic acid, acetic acid and other organic compounds from acidic hydrolysates of plants or vegetable matter, especially spent sulfite liquors after conversion of the pentosans into pentoses and then into furfural by heating the hydrolysate in an acidic environment. The conversion of the pentosans pentoses into furfural, preferably with acidulation, is accomplished in a counterflow or countercurrent flow heat exchanger and a reactor, preferably a tubular reactor. The hydrolysate which has additionally been heated and converted in the reactor is used as a heating medium or heat carrier for heating up the hydrolysate which is converted in the counterflow heat exchanger, whereupon there is recovered as the distillate furfural in conjunction with the formic acid, acetic acid and the like.