SU1343182A1 - Method of burning solid fuel in fluidized bed combustion apparatus - Google Patents

Abstract

The invention makes it possible to increase the combustion efficiency when the firebox is equipped with side slopes by intensive heat transfer from the layer to the flare with particles of the layer. For this, in zones 5 of the gas distribution grid 4 with increased flow rate, the gas velocity is increased with the help of gate 8 so that stable ejections of material from the fluidized bed 1 into the flare zone 2 above layer 1 (flow through layer 1) are organized. Due to the intense heat transfer from the layer 1 to zone 2, with the hot particles of fuel migrating between layer 1 and zone 2, the cost of grinding fuel is reduced and the pyrometric level in the furnace is reduced, which makes it possible to reduce the slagging of the screens and the superheater and Contents of nitrogen oxides, to increase the degree of binding sulfur oxides own calcium oxide in the fuel additive or limestone. 1 il. SL

Description

The invention relates to a method of burning solid fuel in a fluidized bed and can be used in various heat engineering installations.

The purpose of the invention is to increase the combustion efficiency by intensive heat transfer from the layer to the flare with particles of the layer.

The drawing shows a furnace for carrying out the proposed method.

The firebox contains a boiling layer 1, a flare zone 2, fuel feeders 3, gas distribution grid 4 with zones 5 of increased gas or air consumption, path 6 for supplying primary air or recirculation gases for grid 4, path 7 with a gate 8 for supplying and controlling gas flow in zones 5, the slots 9 of the secondary air supply. The firebox is made with ramps 10.

The method is carried out as follows.

Fuel in the form of crushed grain with a grain size of up to 5-10 mm is supplied by the feeders 3 to the boiling layer 1 or over the layer 1. Primary air or recirculation gases along the path 6 are injected under the gas distribution grid 4 and the layer is fluidized. In zones 5 with increased flow rates, the gas velocity is increased with the help of gate 8 so that stable ejections of material from layer 1 to flare zone 2 above layer 1 are organized (flow through layer 1). Combustion in the flare zone 2 is maintained by supplying secondary air to it through the slots 9, which direct the air flow across the movement of fuel from layer 1 to the flare zone 2 Level of layer 1 (the amount of material in layer 1) is maintained by regulating the gas flow to zones 5, t e. intensity of fuel emissions in the torch.

The proposed method of combustion improves the efficiency of work.

Compiled by N. Kolesnikova Editor I. Tupitsa Tehred L. Serdyukova Corrector A. T Sko,

Order 4629/38 Circulation 494Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

unit by reducing the cost of grinding fuel, reduce the pyrometric level in the furnace, for example, by feeding recirculation gases into it without losing stability of the combustion processes. This is achieved as a result of intensive heat transfer from layer 1 to the flare zone 2 with hot fuel particles migrating between layer 1 and zone 2. Reducing the pyrometric level in the furnace reduces or completely eliminates slagging of the screens and the superheater, and reduces the formation of nitrogen oxides during combustion fuel, increase the degree of sulfur oxides bonding with calcium oxide in the fuel or as a lime additive.

The proposed method is suitable for burning various types of solid fuels. At the same time, highly reactive coals and slates do not require additional preparation, and hard coals

and anthracites are first dried and fractionated in size 0-2 and 2-10 mm. The fraction of 0-2 mm domalyvat in mills and served in the furnace through the usual burner device in the flare zone, and the fraction of 2-10 mm burned according to the proposed method.

Claims (1)

Invention Formula The method of burning solid fuel in a fluidized bed furnace by supplying primary air under the grate with at least two streams — central and peripheral — maintaining the last of the fluidized bed conditions, as well as introducing secondary air above the bed, in order to increase combustion efficiency when performing the furnace with side slopes, the speed of the central stream of primary air is chosen from the conditions of the spouting layer.