SU1613804A1 - Method of preparing and combusting solid fuel - Google Patents

Abstract

The invention relates to fuel combustion and reduces nitrogen oxide emissions. This is achieved in that the waste air is divided in the dust collector 8 into low-dust and concentrated flows. Additional fuel (gas or fuel oil) is introduced into the latter and introduced into the furnace 12 below the lightly-polluted stream. Combustion of a concentrated stream produces products of incomplete combustion, which, by reacting with oxides of nitrogen, reduce them to molecular nitrogen. 1 il.

Description

The invention relates to the combustion of fuel and can be used in thermal power plants.

The purpose of the invention is to reduce emissions of nitrogen oxides by reducing them with products of incomplete combustion.

The drawing shows a boiler plant in which the method of preparation and burning of solid fuel is carried out.

The boiler installation comprises a hopper 1 with a feeder 2, a mill 2, a cyclone 4 with a finished dust hopper 5, equipped with a metering feeder 6, a fan 7, a dust concentrator 8 with pipes 9 and 10 of the outlet of the concentrated stream and slightly dusty stream, a boiler 11 with a furnace 12 and an air heater 13 The furnace 12 is equipped with a burner 14 connected by a dust pipe 15 to the feeder 6 of the hopper 5. The air heater 13 is connected by air ducts 16, 17 and 18 to the mill 3 and the burner 14. The pipes 9 and 10 of the dust concentrator 8 are connected to the furnace 12. The pipe 9 of the concentrated flow outlet located below the nozzle 10 of the discharge of slightly dusty stream and it is located gas-oil burner 19.

The method is as follows.

The coal from the hopper 1 is fed by a feeder 2 to the mill 3. Then the coal dust is transported by air to the cyclone 4, in which the main part of the dust (90%) is separated from the exhaust air. Dust enters the dust bin 5, is dosed by the feeder 6 and transported to the burner 14 with hot air from the air heater 13.

The exhaust air with the part of the dust remaining in it (10%) enters the dust concentrator 8, where it is divided into low-soundings. . concentrated and concentrated streams. A slightly dusty stream is introduced into the furnace 12 through the pipe 10, and a concentrated stream through the pipe 9. Into the concentrated stream of exhaust air through a gas-oil burner 19, gas or fuel oil is introduced in an amount that provides an air-fuel ratio (dust, gas and fuel oil) less than stoichiometric.

The dust entering the furnace 12 through the burner 14 burns out with the formation of flue gases containing nitrogen oxides. Flue gases, rising to the top of the furnace, meet the torch of a concentrated stream of exhaust air, in which, when fuel is burned due to lack of air _1B , products of incomplete combustion are formed, for example, carbon monoxide and hydrogen. Products of incomplete combustion, in contact with nitrogen oxides, restore the latter to molecular nitrogen. Residues of unreacted products of incomplete combustion 20 are burned in the upper part of the furnace in a stream of slightly dusty exhaust air.

Claims (1)

Claim The method of preparing and burning solid fuel by drying it with hot air, separating the air mixture into dust and exhaust air, followed by separating the waste air into concentrated and slightly dusty streams and supplying dust and 20 flows of waste air into burning it, characterized in that, with In order to reduce emissions of nitrogen oxides by reducing them with products of incomplete combustion, a slightly dusty stream of exhaust air is fed into the furnace above the concentrated stream, and an additional high-calorific value is introduced into the furnace. ynoe fuel in an amount to provide in the air flow ratio - the fuel is less than stoichiometric.