RU2319894C1 - Method and device for burning high-damp loose wood waste - Google Patents

Abstract

FIELD: incineration of wood waste.

SUBSTANCE: method comprises charging the tower formed by brick walls and clamping grates with wood waste, moving the wood waste down to the sloping fire grate mounted on the bottom of the tower, supplying air under the sloping fire grate by the first fan, igniting the fuel at the sloping fire grate, moving the burning fuel over the sloping fire grate to the furnace chamber to the rotatable fire grate, supplying air to the furnace chamber to the layer of burning fuel through pipes, directing the gas-air mixture formed in the furnace chamber to the tower through the first clamping grate, and igniting the fuel that flows down with the gas-air mixture, by-passing the gas-air mixture through the second clamping grate to the first afterburning chamber, supplying air to the first afterburning chamber by the second fan, directing the gas-air mixture produced to the second afterburning chamber through a port made in the baffle, and directing the mixture to the heat exchanger of the boiler.

EFFECT: enhanced efficiency of combustion.

4 cl, 1 dwg

Description

The present invention relates to the field of heat engineering, in particular to heat-producing plants, and in particular to methods of burning high-moisture wood bulk waste, mainly crushed wood bark, wood chips and sawdust (humidity over 60%), loaded by a mine method, and to devices for their implementation.

Fire chambers with top feed of bulk fuel are known (see Levin R.E. "Heat Engineering", M., State Scientific and Technical Publishing House of Literature on Ferrous and Non-Ferrous Metallurgy, 1951, p. 48-50; 85-87, Schegolev M .M., Gusev Yu.L., Ivanova MS “Boiler units”, M., Publishing house of building literature, 1972, p.96-100, Rabinovich OM “Boiler units”, M. , L., State Scientific and Technical Publishing House of Engineering Literature, 1963, p.114-127).

However, similar devices are characterized for several reasons by low efficiency and low heat transfer coefficient.

The closest in technical essence to the proposed method is a method of burning wood fuel, which consists in the fact that the fuel is loaded into a shaft formed by brick walls and clamping grids and moved down to an angled inclined grate installed on the bottom of the shaft, small wood waste is loaded into a hopper and burned, the resulting air-gas mixture is sent through the first clamping grate to the shaft, dried and ignited in it with the gas-air mixture moving down the fuel, provide burning fuel on an inclined grate, transfer burning fuel along an inclined grate to the combustion chamber to a rotary grate, transfer the air-gas mixture through a second clamping grate to the combustion chamber, from which the mixture is sent to the boiler heat exchanger (see USSR author's certificate No. 91767, IPC F23B 1/04, 1959).

The closest in technical essence to the proposed device is a device for burning wood fuel, known from the same source, containing a shaft formed by brick walls and clamping grids, a combustion chamber connected to the shaft and heat exchanger of the boiler, equipped with a rotary grate and adjacent to the second clamping grid mine, an angled inclined grate installed on the bottom of the mine, covering it at both angles and made with a working surface facing the furnace top oh chamber, and a hopper adjacent to the first clamping grid of the mine.

However, the known method and device do not allow the creation of turbulence in the flows of the gas-air mixture, which prevents the production of high temperature in the combustion chamber. In addition, the known method and device are characterized by increased ash formation and increased toxicity of exhaust gases due to incomplete combustion of fuel, which reduces the efficiency.

The problem to which the present invention is directed, is to increase efficiency.

The technical result provided by the present invention is to improve the combustion process of a highly moist tree bark due to the formation of its circular swirl by directed air supply, increase the completeness of combustion of fuel, and also reduce ash formation.

The specified problem in terms of the method is solved due to the fact that the method of burning high-moisture wood bulk waste consists in loading wood waste into a shaft formed by brick walls and clamping grids and moving it down to an angled inclined grate installed on at the bottom of the mine, air is supplied under the inclined grate with the first blower fan, ignite the fuel on the inclined grate, move the burning fuel along an inclined grate, to the combustion chamber, to the rotary grate, the air is fed into the combustion chamber to the burning fuel layer through pipes, the gas-air mixture formed in the combustion chamber is sent through the first clamping grate to the shaft, the fuel moving downward is dried and ignited in it, the fuel is transferred down the air-gas mixture through the second clamping grill in the first afterburner, air is supplied to the first afterburner by the second blower fan, I pass the resulting gas-air mixture t through a window in the partition into the second afterburner, from which the mixture is sent to the boiler heat exchanger.

The specified problem in terms of the method is also solved due to the fact that the technical result is ensured by the fact that the ash formed on the rotary grate is unloaded onto an ash collector, which removes it from the combustion chamber.

This problem in terms of the device is solved due to the fact that the technical result is that the device for burning high-moisture wood bulk waste contains a shaft formed by brick walls and clamping grids, a combustion chamber in communication with the shaft, equipped with a rotary grate and air supply pipes and adjacent to the first clamping grid of the shaft, an angled inclined grate installed on the bottom of the shaft, closing it at angles and made with an arc transverse profile the surface facing toward the combustion chamber, the first afterburner adjacent to the second clamping grid of the mine and bounded by a partition with a window, the second afterburner connected to the first afterburner through a window in the partition and communicated with the boiler heat exchanger, the first blower connected to inclined grate, and a second blower connected to the first afterburner.

The specified problem in terms of the device is also solved due to the fact that the technical result is ensured by the fact that it is equipped with an ash collector made by a screw and located under the rotary grate.

The drawing shows the proposed device (shaft furnace) for implementing the described method.

The proposed device consists of a shaft 1 for loading fuel (high-moisture wood bulk waste), a combustion chamber 2, a first clamping grill 3, a second clamping grill 4, a first afterburner 5, a rotary grate 6 (a traditional grate with a triangular cross-sectional profile, fixed on the rotary axis 15 and serving for periodically dumping the remains of ash on the auger ash collector 8 by manually turning the axis counterclockwise), the inclined grate 7 (angular fixed an alosnikovy lattice with an arc transverse profile of the working surface, which facilitates the slower movement of fuel descending through the mine 1 with the purpose of preliminary drying it), auger ash collector 8 (it is a small auger conveyor with an electric drive located outside the furnace and serves to periodically remove ash from the furnace), the second afterburner chamber 10, the first blower fan 11 (for supplying air through the inclined grate 7) and the second blower fan 12 (for supplying air to the afterburning chamber 5), pipes 13 (for supplying air to the burning fuel layer in the combustion chamber 2), partitions 14 with a lower window 17 between the first 5 and second 10 afterburners, five viewing windows 16 (for observing the combustion process), four of which are installed on the rear wall of the furnace, and one on the furnace door 18 (for access during preventive maintenance), a smoke exhaust fan 19 (serves to create forced draft) and a frame of a welded structure 20 made of a steel channel and serving as the base of the shaft furnace. The layer of fuel flowing through the shaft 1 is indicated by 9. The air supply directions are indicated by wavy arrows, and flue gas movements are indicated by straight arrows.

The described method is as follows. Fuel 9 is loaded into the shaft 1. Moving down between the two clamping grids 3 and 4 along the shaft, it falls onto the inclined grate 7 under pressure of the blower fan 11. On the inclined grate 7 there is a primary “combustion mirror” (surface of the burning fuel layer) ) The resulting flue gases enter the combustion chamber 2, into which air is supplied through the pipes 13 to the burning fuel layer 9. The air, mixed with the flue gases, forms a gas-air mixture, which passes through the first clamping grid 3, penetrates the fuel layer 9, descending along the shaft 1 , dries and ignites it, forming a secondary “combustion mirror”, and through the windows of the second clamping lattice 4 enters the first afterburner 5. When passing through the clamping lattices 3 and 4, the gas-air mixture heats the brick walls of the shaft 1, by accelerating the pyrolysis process and eliminating the hang of fuel 9. For complete chemical oxidation and combustion of small particles of fuel 9 passing through the windows of the second clamping lattice 4 into the first afterburner 5, air is directed into it by the blower fan 12. Final afterburning and purification of flue gases occurs in the second afterburner 10, from where the heat flow is directed to the boiler heat exchanger (not shown in the drawing), to which this shaft furnace serves as a source of thermal energy (pre-furnace). The ash, shifted by a burnt-out layer of fuel and blown through the slots of the inclined grate 7, is carried out to the rotary grate 6, which, turning around its axis 15, unloads it on the screw ash collector 8. The latter removes the ash from the furnace beyond its limits.

The power of the shaft furnace is controlled by dosing the fuel supply. The rate of fuel combustion is regulated by the supplied air.

This ensures maximum combustion of fuel with minimal ash formation and elimination of slagging in the hearth and corners of the shaft 1, since they are closed by an inclined grate 7, which is under constant pressure of the air blown by the blower fan 11 (both of these factors are problematic when operating existing heating systems, fuel in which high-moisture wood bulk waste is used).

Claims (4)

1. The method of burning high-moisture wood bulk waste, which consists in the fact that the wood waste is loaded into a shaft formed by brick walls and clamping grids and moved down to the angled inclined grate installed on the bottom of the mine, air is supplied under the inclined grate by the first blower, ignition of fuel on the inclined grate, move the burning fuel along the inclined grate to the combustion chamber on the rotary grate, served in the flask to the burning fuel layer, the air through the pipes formed in the combustion chamber, the air-gas mixture is sent through the first clamping grate to the shaft, the fuel moving downwards is dried and ignited therein, the air-gas mixture is passed through the second clamping grate to the first afterburner, the air is fed into the first afterburner with the second blast fan, the resulting gas-air mixture is passed through a window in the partition into the second afterburner, from which the mixture is sent to the heat exchanger la. 2. The method according to claim 1, characterized in that the ash formed on the rotary grate is unloaded onto an ash collector, by which it is removed from the combustion chamber. 3. A device for burning high-moisture wood bulk waste containing a shaft formed by brick walls and clamping grids, a combustion chamber in communication with the shaft, equipped with a rotary grate and air supply pipes and adjacent to the first clamping grate of the shaft, an angled inclined grate installed at the bottom of the shaft, covering it at both angles and made with an arc transverse profile of the working surface facing the combustion chamber, the first afterburning chamber adjacent to the second a mine clamping grid and bounded by a partition with a window, a second afterburner connected to the first afterburner through a window in the partition and communicated with the boiler heat exchanger, a first blower connected to the inclined grate, and a second blower connected to the first afterburner. 4. The device according to claim 3, characterized in that it is equipped with an ash collector, made auger and located under the rotary grate.