Khd Humboldt Wedag Gmbh

Heiko Schuermann

Marc Feiss

Florian Nassenstein

Rolf Gussmann

Andreas Hand

A method and a corresponding plant for denitrifying bypass exhaust gases in a cement clinker production plant. Raw meal is sintered in a rotary kiln and deacidified in a calciner. A rotary kiln inlet chamber is connected to the calciner directly or by a riser duct. Bypass exhaust gas is drawn off near the inlet chamber. This exhaust gas is guided into a first mixing chamber, in which the exhaust gas is cooled to between 800 and 950 degrees C., then the exhaust gas is guided through a reaction pipeline segment, wherein the dwell time is between 0.5 and 3 seconds and ammonia, aqueous ammonia solution, or ammonia-releasing substances are injected for denitrification. Then the exhaust gas is guided into a second mixing chamber, in which the exhaust gas is cooled to between 150 250 degrees C. Then the exhaust gas is guided to a filter for dust removal.

Method and plant for denitrifying bypass gases in a multi-stage system of mixing chambers in a plant for producing cement clinker

A plant for producing cement clinker, comprising as viewed in the direction of materials flow, a heat exchanger to preheat raw meal, a downstream calciner to calcine the raw meal, a rotary kiln to sinter the calcined raw meal, and a clinker cooler to cool the sintered cement clinker. A combustion device which carbonizes, pyrolysis or burns difficult fuels, is embodied as a pot reactor or gooseneck reactor in an inverted U-shape, and is positioned upstream of the calciner on the flow path of the exhaust gases from the rotary kiln to the calciner, and has a gas outlet that opens out above a tertiary-air line of the clinker cooler into the calciner. As a result, it becomes possible to burn fuel which is lumpy and/or has poor ignitability, and the gases from incomplete combustion in the reactor are available in the calciner in gaseous form for further combustion.

Plant for producing cement clinker with gasification reactor for difficult fuels

Denitrifying bypass exhaust gases in a cement clinker producing plant. The plant comprises a rotary kiln connected to a calciner for the deacidification of raw material or to a rotary kiln riser shaft via a rotary kiln inlet chamber, and the bypass exhaust gas being drawn off in the region of the rotary kiln inlet chamber. The method comprises: cooling the bypass gas to between 260 C and 400 C in a cooling device, injecting an ammonia-, urea-, and/or ammonium-containing substance into the cooled bypass gas, introducing the cooled and mixed bypass gas into a ceramic filter system to filter out any halide and sulfate of the alkali metals and alkaline-earth metals precipitated during cooling the gas, and any nitrogen not reacted by the injected substances is chemically selectively reduced over a catalytic converter which is located in or directly downstream of the ceramic filter system.

Method for denitrification of bypass exhaust gases in a plant for producing cement clinker

A method for using waste heat from a cement producing plant, wherein heat of a process gas is used through a heat exchanger, which comprises a sequence of cyclones, for heating raw mix. A cement producing plant having at least one calcinator and at least one heat exchanger, which comprises a series of cyclones for heating raw mix. The process gas is removed at the outlet of the calcinator and/or at the gas-side outlet of the first cyclone in the heat exchanger in the direction of gas flow and, once the heat has been removed in a steam vessel, the cooled process gas is fed back into the second cyclone or third cyclone in the heat exchanger in the direction of gas flow. The heat taken from the process can be used for the further heating of unrecovered heat which can thereby be more efficiently converted into electrical energy.

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Leverkusen, Germany

Heiko Schuermann