Flsmidth A/s

Kent Thomsen

Lars Skaarup Jensen

Alexander Helm

Described is a method as well as an apparatus for incineration of combustible waste during the manufacture of cement clinker by which method the waste is introduced via a waste inlet () and supported on a supporting surface () incorporated in a separate compartment (), where the waste being actively transported, while simultaneously subjected to incineration, through the compartment to its outlet (), where the hot exhaust gases produced in connection with the incineration of the waste being vented to the preheater system for heating the cement raw meal, and where the slag generated during the waste incineration process being extracted from the compartment (). The method and the apparatus are peculiar in that exhaust gases containing NOx are introduced to the compartment ().

Method and apparatus for incineration of combustible waste

Described is a plant for manufacturing cement clinker comprising a preheater () which comprises at least one last cyclone () and at least one next-to-last cyclone () which is connected in series via a gas duct () to and fed with a gas from the last cyclone (), a calciner () which comprises at least one inlet opening () for introducing preheated raw meal from the last cyclone (), and which is connected to a subsequent separating cyclone (), a gas duct () which connects the separating cyclone () to the last cyclone (), and which comprises at least one inlet opening () for introducing preheated raw meal from the next-to-last cyclone (). The plant is peculiar in that the inlet opening () for introducing preheated raw meal from the next-to-last cyclone () into the gas duct () which connects the separating cyclone () to the last cyclone () in a vertical plane is located under at least one inlet opening () for introducing preheated raw meal from the last cyclone () into the calciner. Hence, without affecting the installation height of the preheater, it will be possible to locate the last cyclone () of the preheater () at an arbitrary height relative to the calciner (), and preheated raw meal from the last cyclone () can therefore be introduced at any point into the calciner () without any use of lifting equipment.

Plant for manufacturing cement clinker

A description is given of a method as well as a plant for manufacturing cement clinker by which method cement raw meal is preheated in a preheater ( ), calcined in a calciner ( ) comprising an upper end ( ) and a lower end ( ), burned into clinker in a kiln ( ) and cooled in a subsequent clinker cooler ( ). The invention is peculiar in that exhaust gases from the kiln ( ) are introduced into the upper end ( ) of the calciner, in that fuel is likewise introduced into the upper end ( ) of the calciner, in that the exhaust gas/fuel suspension is directed down through the calciner ( ), in that preheated air from the clinker cooler ( ) and preheated raw meal from the preheater ( ) in combination or separately are fed into the calciner ( ) at a location under the zone where exhaust gases from the kiln and fuel are introduced, in that the preheated air is directed down through the calciner ( ), being gradually mixed with the exhaust gas/fuel suspension, in that the raw meal under the action of gravity is directed down through the calciner ( ) along its wall, being suspended in the exhaust gases at the lower end ( ) of the calciner, and in that the exhaust gas/raw meal suspension is extracted from the lower end ( ) of the calciner and conveyed to a separating means ( ) for separating the raw meal which is subsequently directed to the kiln ( ). Hereby is obtained a significant reduction of the NOx which is led to the calciner together with the kiln exhaust gases, a high degree of fuel burn out even when using fuels with a low content of volatile constituents, and a low degree of conversion into NOx of the nitrogen which is led to the calciner together with the fuel.

Growing community of inventors

Roskilde, Denmark

Kent Thomsen