Combustion technology, boiler technology and flue gas cleaning for Energy from Waste plants

Air or water-cooled pusher type grate firing with ram feeders up to 130 MWth.

Thermally and mechanically highly resilient combustion systems with an intelligent combustion control. The fuel is metered via a ram feeder. Each grate zone is individually controllable including multi-stage primary air distribution. Secondary air injection is via rows of nozzles in the front and rear walls of the combustion chamber.

Fluidised bed combustion up to 100 MWth

The fuel is fed into the fluidised bed through openings in the side walls of the combustion chamber. The combustion air and the recirculated flue gas are added in the nozzle floor and in several secondary air or tertiary air levels.

Steam capacities up to 150 t/h - Steam parameters up to 500 °C / 100 bar.

Steam generator in natural circulation design with two or three vertically arranged radiation passes and a subsequent horizontal convection pass. Depending on the application, the first and second or third boiler passes are designed as empty passes and are divided into combustion chamber and radiation chambers. The horizontal boiler path accommodates the superheater, evaporator and economiser convection heating surfaces. All convection heating surfaces can be cleaned during operation with a rapping device. Depending on the user profile, however, a vertical boiler design with three or four boiler passes can also be used. The superheated steam temperature is controlled by means of a multi-stage injection cooler between the superheater bundles.

Safe compliance with the statutory emission limits is ensured by a downstream flue gas cleaning system. Semi-dry or dry process variants are used. Calcium hydroxide Ca(OH)₂, calcium oxide CaO or sodium bicarbonate NaHCO₃ are introduced into the flue gas as additives to absorb the acidic gas components. Alternatively, wet processes can also be used.

Heavy metals and organic substances such as dioxins and furans are separated by adsorption on mill-activated lignite coke or activated carbon. Fabric filters, electrostatic precipitators or cyclones provide the necessary particle separation. The fabric filter in particular, which is preferably used, guarantees minimum dust emissions as well as, the lowest pollutant concentrations in the clean gas through intensive separation and adsorption processes in the filter cake. The flue gases are optionally denitrified by means of an SNCR process (Selective Non Catalytic Reduction) or an SCR process (Selective Catalytic Reduction).