Khd Humboldt Wedag Ag

Andreas Hand

Stephan Kuhnke

Hubert Ramesohl

Carsten Eckert

Michael Brachth&auml;user

Norbert Streit

Robert Mathai

Stepan Kuhnke

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

In order to create, for cement clinker production lines, a calcinator that is connected upstream from the rotary tubular kiln and is equipped with two firings, which enables on the one hand a high-grade calcinated raw meal and on the other hand an exhaust gas with very low NO emissions, as well as a burning that is as complete as possible of remaining CO-containing NO reduction zones, it is provided that a combustion point with sub-stoichiometric fuel combustion be arranged both in the rotary kiln exhaust gas ascending line and also in the cooler outgoing air line which form a first and section portion, respectively, of the calcinator and that downstream in a flow direction of the suspension, additional combustion air discharges into the calcinator which combustion air is branched off from the tertiary air line coming from the clinker cooler via at least one branch line.

Method and apparatus for thermal treatment of mealy raw materials

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.

Process for the thermal treatment of meal-form raw materials

In order to create a calcinator preceding the rotary tubular kiln and equipped with secondary firings in which inert fuels that are difficult to ignite or, respectively, difficult to burn (secondary fuels) can be beneficially disposed of by burning for the purpose of calcination of the cement raw meal and a complete burn-out of CO gas strands and other fuel constituents, as well as an exhaust gas with low No,, are nonetheless assured for cement clinker production lines, the tertiary air channel in the region of the calcination unit is fashioned as a combustion chamber that expands the channel cross-section and through which the suspension flows from bottom to top. Tertiary air having a torsion component as well as an easily ignitable fuel is centrally introduced at the lower end of the combustion chamber, whereby a high-temperature zone that extends centrally from bottom to top and has a hot core flame proceeds from this burning location. An inert fuel that is difficult to ignite or, respectively, difficult to burn (secondary fuel) is introduced into the high-temperature zone and is burned and, thus, is usefully disposed of for the purpose of calcining the raw meal.

System for the thermal treatment of meal-like raw materials

In order to create, for cement clinker production lines, a calcinator that is connected upstream from the rotary tubular kiln and is equipped with two firings, which enables on the one hand a high-grade calcinated raw meal and on the other hand an exhaust gas with very low NO,emissions, as well as a burning that is as complete as possible of remaining CO-containing NO,reduction zones, it is provided that a combustion point with sub-stoichiometric fuel combustion be arranged both in the rotary kiln exhaust gas ascending line and also in the cooler outgoing air line which form a first and section portion, respectively, of the calcinator and that downstream in a flow direction of the suspension, additional combustion air discharges into the calcinator which combustion air is branched off from the tertiary air line coming from the clinker cooler via at least one branch line.

Growing community of inventors

Kö'ln, Germany

Andreas Hand