SU1744370A1 - Fuel combustion method - Google Patents

Abstract

Invention m. used in fuel burners for various purposes. The aim of the invention is to improve the completeness of the combustion of fuel. When implementing the method, it is possible to organize the extraction of large burnt fuel particles from the surface of layer 3. So from the area near the gas distribution grid 2. When implementing the method, air is supplied through the gas distribution grid 2 and coarse fuel through the feeder 5 into the fluidized bed 3 of material whose density exceeds the density of large particles of fuel, and the ratio of the densities of the material of layer 3 and large particles of fuel is maintained in the range of 1.9-2.6. carry out the continuous removal of material of layer 3, the separation of small burnt particles (ash) and the return of material to layer 3. Before the output of burnt-out large fuel particles, the indicated density ratio is changed depending on the output zone. After the conclusion of the withdrawal, the ratio of the densities of the material of the layer 3 and the coarse particles of the fuel is restored to its original value. The change in the ratio of densities is provided by changing the amount of ash and the material of the layer itself (magnesia, sand), as well as the ratio of fuel particles of different fractions in the combustion chamber 1. 1 Cp f-ly. 2 Il. / W WITH with

Description

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The invention relates to energy and can be used in fuel-burning devices for various purposes.

The purpose of the invention is to increase the completeness of the combustion of fuel.

FIG. Figure 1 shows a scheme that implements the method in which, the particulates are removed from the region near the gas distribution grid; in fig. 2 - the same, particulates are removed from the surface of the layer.

The scheme for implementing the method of burning fuel comprises a combustion chamber 1 with a gas distribution grid 2 and a fluidized bed 3, a fuel tank 4 with a feeder 5, a drain pipe 6 connected to a magnetic separator 7, a feeder 8 of inert material, ash bin 9, a sieve 10 connected 11 large particles of fuel, bunker 12 of layer material, drain valve 13 and ash feeder 14 to the bunker.

The method of burning fuel is implemented as follows.

The air through the gas distribution grid 2 enters the combustion chamber 1 and liquefies the material of layer 3. As the material of layer 3, a mixture of expected particles of ash and magnetite with a density of 5000 kg / m is used when implementing the method of FIG. 1 or sand with a density of 2700 kg / m3 when implementing the method of FIG. 2. The mass fractions of the components of the mixture are selected in such a way as to ensure that the density of the material of the layer 3 and the large particles of coal in the range of 1.9-2.6. At the same time, from the conditions of optimality of the process, the maximum velocity of the gases in chamber 1 should not exceed 3.0 m / s. Coarse fuel with a density of 1300 kg / m and a size from 0 to 100 mm from the hopper 4 enters the feeder 5 and then to the surface of layer 3. At a maximum gas velocity of 3.0 m / s, coal particles less than 10 -15 mm.

During operation, the material of layer 3 is continuously removed from the discharge pipe 6 and sent to the magnetic separator 7, where it is separated from the small burnt particles (ash) and returned to the combustion chamber 1. Ash from the separator 7 with a density of 900 kg / m sent to hopper 9 or to discharge. The fuel consumption and the rate of selection of the material of the layer 3 from the nozzle 6 are selected in such a way as to maintain the specified density ratio. In this case, the large particles of fuel are distributed evenly over the volume of the fluidized bed 3 and are vigorously stirred. When accumulating in the volume of layer 3 a significant amount of burnt-out large particles proceed to the preparation and removal of the latter from chamber 1. The fuel from bunker 4 begins

enter the sieve 10, from where only fine particles of coal are fed to the feeder 5 and then to the combustion chamber 1, and large particles to the bunker 11. At the same time, the ratio of the densities of the material of the layer and large

0 particles of fuel in the combustion chamber 1 to 3.3-4.0 when removing large burnt particles from the surface of the layer or 1.7-1.6 when removing particles near the gas distribution grid 2. To do this, in the first case, feed 8 is additionally served magnetite from the hopper 12. In the combustion chamber 1, due to the increase in density of layer 3, the burnt out large particles float to the surface of layer 3 and are concentrated at the discharge device 13. During this time, the bulk of the fuel particles have time to burn out. Burnt coarse particles are removed. At the end of the drain valve drain device 13 is closed. In the second case

5 (decreasing the density ratio to 1.7-1.6) reduces the density of the material of the fluidized bed 3 to 1500 kg / m3 by adding 1 burnt particles (ash) from the bunker 9 to the combustion chamber. In addition, from the separator 7, small burnt out particles (ash)

also enter the combustion chamber 1, and

 sand - in the bunker 12. At the same time it has to be

A ratio of ash to

sand 2 1. Upon reaching it, all the burnt out large particles are concentrated near the gas distribution grid 2. After the particles are located in this area, the drain devices 13 are opened and the particles are removed from the combustion chamber 1. After the end of the drain, the valve on the drain device 13 is closed and brought the ratio of the density of the material of the layer and large particles of fuel to the initial one when the supply of coarse-grained fuel is resumed. In this case, when it is necessary to reduce this ratio, the magnetite from the separator 7 enters the hopper 12, and the feeder 8 is turned off. Ash from the hopper 9 is fed to the feeder 14 and further to the furnace

0 chamber 1. When the ratio of densities 1.9-2.6 is reached, the ash supply from the bunker 9 to the feeder 14 is stopped and the magnetite from the separator 7 to the feeder 8 is resumed.

5 large particles of fuel from the bunker 11. If necessary, increase the ratio of the densities turn off the ash supply from the bunker 9 to the combustion chamber 1, resume the flow of sand from the separator 7 and the bunker 12. Upon reaching the density of the material

2700 kg / m3 (actually pure sand) transfer to the mode of burning coarsely crushed fuel.

Claims (2)

Claim 1. The method of burning fuel consists in supplying air to the layer formed by boiling inert material, small and large particles of coarsely crushed fuel, and the ratio of the density of the layer and large particles of fuel exceeds one, as well as collecting and unloading large burnt particles their accumulation from the boundary of the layer, characterized in that, in order to increase the completeness of combustion, the feeding and unloading of correspondingly large fuel particles and large burnt particles is carried out periodically with alternation between fight, and during the filing period About Large burned-out particles Large particles of thickness / weld coarse particles of fuel additionally organize continuous removal of material layer with small burnt particles separation of the latter from the material of the layer and returning the latter to the combustion zone while maintaining the density ratio of the layer and coarse fuel particles in the range of 1.9-2.6. and in the period of unloading of large burnt particles, small burnt particles or material are fed into the layer while maintaining the ratios of layer densities and large fuel particles in the ranges 1.7-1.6 or 3.3-4.0, respectively. 2. Capable of claim 1, which is different In that, between the unloading and feeding periods, small burnt particles or material are fed into the layer when the ratio of densities changes to the specified range of 1.9-2.6 for the specified feeding period. Air 0U.2 Sbrk