SU1574987A1 - Method of burning in fluidized bed and device for effecting same - Google Patents

Abstract

The invention relates to energy and can be used in the combustion of high ash coals in a fluidized bed. The goal is to increase efficiency by more complete combustion of high-ash fuel. When solid fuel in the fluidized bed is burned in the furnace 2, a solid residue entrained in the flow of the flue gases is precipitated in precipitator 6 and trap 7, then in collection hopper 8, which functions as a pneumatic classifier. When part of the total air flow entering the furnace 2 for incineration is liquefied, the solid residue in the bunker 8 is returned to the furnace 9 to the afterburner through the pipe 9 and the ash and waste fraction is removed through the pipe 9 in the ash dump. This increases the degree of burnout of fuel and fuel, decreases the rate of circulation of entrainment and increases thermal efficiency. 2 sec. f-ly, 1 ill.

Description

I The invention relates to energy and can be used in the combustion of high-ash coal and coal preparation waste with the subsequent use of the heat of combustion products in boilers and other heat-consumption.

The purpose of the invention is to increase efficiency by more complete combustion and heat recovery when burning high-ash fuel.

The drawing shows a device for implementing a fluidized bed combustion method.

I The device for burning in the fluidized bed contains a furnace 2 supplied with pipe 1 for supplying fuel, in the lower part of which there is a gas distribution grill 3 connected to air source 4, and in the upper part of the furnace 2 a window 5 is made through which the furnace 2 is connected successively to the precipitator (6 and the solid residue catcher 7, connected to the collecting bin 8, in turn, via a recycling pipe 9 and a flow divider 10, respectively, with the furnace 2 and the air source 4. The nozzle 11 is connected to the bunker 8 water ash. Large particles of solid residue are retained in the precipitator 6 by gravitational forces, and the trap 7 can be made of a centrifugal type (battery cyclone). As an air flow divider 10, an adjustable valve installed on the bypass pipe 12 or a three-way valve ( not shown), by means of which the air source 4 (fan) is connected by pipelines (not shown) to the gas distribution grid 3 and the collecting bin 8 "The collecting bin 8 performs the functions of a pneumo-classifier,

The method of burning in a fluidized bed is carried out in the installation as follows:

A part of the air flow from the blower fan is fluidized by a layer of ash 9 preheated to 800-850 ° C and left in the furnace 2 or specially brought into it from the heap. For heating, they use liquid fuel injected into furnace 2 or low-ash lump fuel, for example, wood waste. Then in

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the furnace 2 through the pipe 1 serves fresh fuel. A solid residue carried away by the flow of flue gases, which is a mixture of unburned fuel particles and ash, is precipitated in precipitator 6 and trap 7, of which the residue flows by gravity into the pneumatic classifier. In it, the part of the total air flow coming from the blower fan through the flow divider 10, the captured solid residue is classified into a fraction with a high content of combustible and Aracution, containing mainly ash with waste rock. The first fraction is returned in the air stream to the furnace 2 for afterburning, and the ash and waste rock are periodically removed through the outlet 11 to the ash dump.

The amount of air supplied to the pneumoclassification of unburned solid combustion products is regulated depending on the fractional composition of the fuel, indirectly controlled by the load on the pneumoclassifier. The total air flow rate is kept constant in an amount determined by the concentration of combustible in the initial fuel, the thermal performance of the boiler unit and the required hydrodynamic parameters of the furnace volume.

The fraction of solid particles with a high content of combustible (compared to ash) is returned to afterburning in the superlayer space at a temperature higher than the bed temperature by 40 ° on average. This leads to an expansion of the zone of active combustion of solid fuel, an increase in the degree of burnout of combustible space, reduction of mechanical incompleteness of fuel combustion, reduction in the rate of circulation of ash and increase in the efficiency of the furnace 2.

Claims (2)

Invention Formula 1 "A method of combustion in a boiled bed, consisting in feeding solid fuel and air into the latter, removing combustion products and separating solid residue from the latter, feeding it into the accumulation zone and further returning unburned fuel to the fluidized bed by means of a portion of the total air, pod5 for combustion, characterized in that, in order to increase efficiency by more complete combustion and heat recovery when burning high-ash fuel, before returning unburned fuel to the layer in the accumulation zone, the said part of air also classifies the solid residue into ash and unburned fuel, the first of which is derived from the accumulation zone, 2. A device for combustion in a fluidized bed, containing a furnace supplied with a fuel supply nozzle, in the lower part of which a gas-fired gas is installed. 74987 a distribution grid connected to an air source, and a window in the upper part of the furnace is made through which the furnace is connected to a solid residue catcher connected to a collecting bin, in turn, through a recirculation pipeline and a divider of current to the furnace and an air source , characterized in that, in order to increase efficiency by more complete combustion and heat recovery during the combustion of high-ash fuel, it additionally contains a ash outlet connected to the collecting bin „ Editor M0 Pandora Compiled by N. Bel Kova Tehred M. Khodanich Proofreader L. Beskid Order 1775 Circulation 455 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and Publishing Combine Patent, g, Uzhgorod, st. Gagarin, 101 Subscription