Khd Humboldt Wedag Ag

Khd Humboldt Wedag Gmbh

Carsten Eckert

Andreas Hand

Norbert Streit

Hubert Ramesohl

Ralf Filges

Horst Schilling

Matthias Mersmann

Hans-Wilhelm Meyer

Stephan Kuhnke

Heiko Schürmann

Stefan Köllen

Robert Mathai

Stefan K&ouml;llen

Stepan Kuhnke

A cement clinker production line with a calcining stage connected upstream of the rotary tubular kiln including an integrated calcining combustion chamber, with a CO-containing reduction zone whose size and reduction potential can be adapted to different NOcontents contained in the kiln exhaust gas and/or different types of secondary fuels used in the combustion chamber. The combustion chamber has an upper, raw-meal-free reducing zone with a feed for secondary fuels, and first tertiary partial airstream with sub-stoichiometric fuel combustion for gasifying the secondary fuels. The combustion chamber has a lower zone. The inflow for at least one raw meal partial stream and one second tertiary partial airstream are arranged in the junction region of the upper zone and the lower zone. The height (H) of the upper zone in relation to the height (h) of the lower zone has a ratio of approximately 5:1 to approximately 1:1.

Installation for producing cement clinker, and method for operating one such installation

The aim of the invention is to create a bypass system for a cement clinker production line, which is characterized by particularly low investment costs and operating costs, thus being economically favorable. Said aim is achieved by installing the bypass system in such a way that the capacity of pre-existing system filters such as the main exhaust gas filter and/or the cooler exhaust filter can also be used for treating the bypass gas flow.

Cement clinker production comprising partial removal of a flow of rotary kiln exhaust gas containing harmful substances

In order to provide a comparatively simple and cost-effective method for cement clinker production lines where especially raw materials and/or fuel/secondary fuel containing chlorine compounds and a partial gas extraction with an electrostatic dust collector as waste gas dust remover are used, with which the risk of emitting the waste gas pollutants dioxin and/or furan is eliminated, it is proposed in accordance with the invention that the extracted quantity of the partial gas extraction stream, after cooling and electrostatic dust removal, is held lower than the sum of the secondary air drawn through the rotary kiln and the tertiary air drawn past the rotary kiln, and to recirculate the cooled and dedusted partial gas extraction solely into an area of the clinker cooler in which the recuperation air is removed from the clinker cooler, and the dioxins and/or furans of the partial gas extraction are decomposed in the clinker cooler on the hot cement clinker and/or deposited and/or decomposed by the high temperature treatment in the burners of the rotary kiln and the precalcinator.

Method for emission control of dioxin and/or furan waste gas pollutants in a cement clinker production line

A dual-train or multi-train installation for the production of cement clinker from raw meal includes several cyclone suspension heat exchanger trains which provide substantially equal gas and meal loads of the following gas-solid suspensions through use of a vortex homogenization chamber ( ), having an inlet opening ( ) for the gas-solid suspension and having at least two outlets to a pair of pipes ( ) for the discharge of the thoroughly blended homogenized gas-solid suspension substreams. The vortex homogenization chamber ( ) is positioned in a calcination stage ( ), upstream of its branching and splitting between the several heat exchanger trains (A, B).

Multi-train installation for the production of cement clinker from raw meal

In order to provide a cement clinker production line with a calcinator connected to the rotary kiln and including a separate rotary drum-type reactor with the objective to safely burn even coarse secondary fuels in the drum-type reactor and also to evenly and effectively transfer the released heat energy to the cement raw meal, it is proposed in accordance with the invention to introduce into the rotary drum-type reactor on the inlet side for the solids a partial stream line of the tertiary air guided from the clinker cooler to the calcinator, a highly ignitable fuel, the low ignitable or low flammable secondary fuel and a partial stream line for the cement raw meal and to connect the exit side for the material on the rotary drum-type reactor via a line for carrying out the solid residues to the tertiary air channel and/or the rotary kiln exit gas channel of the calcinator and/or to the inlet chamber of the rotary kiln.

System for manufacturing cement clinker

Cement clinker production apparatus having a precalcination stage connected upstream of a rotary kiln, in which precalcination stage a CO-containing reduction zone in the rotary kiln off-gas duct is employed for the purpose of reducing the pollutant NO . In order to make certain that the quantitative ratio of O in the rotary kiln off-gas to fuel admitted by a deNO burner, and thus control the effectiveness of NO reduction, a pivoting throttle valve ( ) is positioned in the precalcination stage to control the quantity of rotary kiln off-gas and thus the O content in the kiln off-gas. The throttle valve ( ) is positioned in the rotary kiln off-gas duct ( ) above the deNO burner ( ), above the raw meal inlet ( ), and before the confluence of the tertiary air substream with the rotary kiln off gas. The throttle valve ( ) is pivotable about an articulation ( ) at the bottom side of the valve so that the flow of the rotary kiln off-gas remains laminar, thus enhancing the reaction length of the CO-containing reduction zone ( ).

Apparatus for thermal processing of raw material in meal form

A system for the manufacture of cement clinker from cement raw meal in which the off-gases of the cement clinker production line not only undergo denitrification but also undergo desulfurization, so that even sulfur-rich raw materials and fuels can be employed without exceeding the prevailing pollutant emission limits. A substream of the oversize material ( ) discharged from the mixing chamber ( ) of the precalcination stage ( ) as solid sorbent may be combined with the off-gas ( ) and/or with a partial gas discharge ( ) of the rotary kiln off-gas in order to convert the sulfur oxides contained in those off-gases to calcium sulfate ( ), which is subsequently separated from the system off-gas.

Method for desulfurization of off-gases of a system for the manufacture of cement clinker

In order to create a process for the economical production of cement clinker in a cement clinker production line with a raw meal preheater, a precalcination stage, a rotary tubular kiln and a clinker cooler, in which the total oxygen excess required for all firing points, i.e., the ratio of total oxygen to total fuel, also designated as &lgr; value, is to lie as low as possible, it is proposed according to the invention, to continuously measure the content of CO and/or (unburned) hydrocarbons and/or other combustion products in the exhaust gas path of the precalcination stage and, in dependence on this measurement value, to perform a regulating intervention on the amount of an oxidation agent and/or catalyst to be injected into the precalcination stage.

Growing community of inventors

Cologne, Germany

Carsten Eckert