SU1418545A2 - Cyclone furnace for burning up wooden dust - Google Patents

Abstract

The invention relates to the incineration of finely dispersed waste in enterprises of the woodworking industry, namely to the incineration of wood dust, which is obtained by grinding chipboard. The purpose of the invention is to increase the reliability of the afterburning chamber. The interwell area 10 of the afterburner chamber 7 is filled with metal, for example aluminum, and provided in its upper part with an annular manifold 11 with vertical pipes 12 for feeding through their open ends into the lower part of the afterburner of inert gas, an example of nitrogen. The open ends of the vertical pipes are made with a bevel towards the inner wall of the afterburning chamber. 1 hp f-ly, 3 ill.

Description

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The invention relates to the field of burning fine wood waste in enterprises of the woodworking industry, namely the burning of wood dust containing burning substances, which is obtained by grinding chipboard, and is an improvement of the known furnace according to the main author. St. No. 1193367.

The purpose of the invention is to increase the reliability of the afterburning chamber.

FIG. 1 shows a cyclone furnace for burning wood flu; in fig. 2 shows section A-A in FIG. one; in fig. 3 7 section BB in FIG. one.

The cyclone burner for wood burning contains a combustion chamber 1 with a double-walled casing made of two shells 2 and 3, forming a closed interwall space 4 and equipped with a wood dust inlet 5 with air tangential nozzles 6 connected to the afterburning chamber 7 by means of clamping 8. The interwall space 4 of the housing of the combustion chamber 1 is filled with metal with a melting point 300-400 o higher than the self-ignition temperature of dust,

WITH.

The afterburning chamber 7 is provided with tangential air supply nozzles 9, and its in-wall space 10 is filled with metal, for example aluminum, and provided with an annular collector 11 with vertical pipes 12, the open ends of which are made with a bevel towards the inside wall of the afterburning chamber 7. The collector 11 is connected to a cooling system comprising a gas blower 13, a heat exchanger 14, pipelines forming a closed circulation loop 15 filled with an inert gas, for example nitrogen. Combustion and afterburning chambers are equipped with ducts 16 and 17 with inlets 18 and 19. The combustion chamber 1 is covered with thermal insulation 20 and provided with a pilot 21. The walls of the nozzles 6 are covered with thermal insulation 22.

The furnace works as follows

The gas blower 13 is turned on. For ignition, a mixture of natural gas and air is fed through the pipe 18, which, passing through the tangential nozzles 6, enters the combustion chamber 1 and ignites therein from the igniter 21. Pr

burning natural gas in the combustion chamber heats its walls, and hence the shell 2, through which the metal in the interwall space 4 is heated. After heating the metal to the melting temperature (for aluminum, it is equal), which is controlled by temperature (not shown) Wood dust is fed through the nozzle 5, it is picked up by a vortex gas-air flow supplied through the tangential nozzles 6, gasified, ignited and partially burned. The combustion products through the clamp 8 and the afterburning chamber 7 are removed from the furnace. After a stable burning of the wood flume has been reached, the supply of natural gas is stopped, primary air is supplied through pipe 1B, and secondary air is supplied through pipe 19. The primary air through the nozzles 6 is fed at a speed of 30-50 m / s, the secondary air through the nozzles 9 at a speed of 110-120 m / s. The combustion process in the combustion chamber is carried out at 700-800 ° C with an air flow rate less than one. The incompletely burnt wood and the gases released at the same time, through the clamp 8, enter the afterburning chamber 7, where their complete combustion takes place in the tangential flow of secondary air, the discharge coefficient of which is higher than one unit.

The afterburning process is carried out at a temperature above 1300 ° C, since at this temperature, the burning of poisonous gases occurs, which is obtained during thermal decomposition into burning substances found in a wood vodka. Moreover, at such temperatures due to the interaction of wood ash and plunger press-. The dacha stone, which falls into the wood pitch when grinding particle boards, produces liquid slag, since its melting point is equal. Slag flows from; afterburners, and the flue gases are sent for technological needs, for example for drying the ground wood from which chipboard is made.

Due to the fact that the temperature of the dm gases in the chamber / afterburning is 1300 ° C, the metal in the interwall space 10 melts. Therefore, the inert gas by the gas blower 13 begins to be pumped in a closed way.

cooling system contour. It is fed to a collector 11, then enters a vertical pipe 12, through which the downward flow is directed to the bottom of the afterburner. Due to the fact that the open ends of the vertical pipes 12 are made with a bevel towards the inner wall of the afterburner chamber, inert gas splashes in close proximity to this wall, which causes intense mixing of the metal in the near-wall region, which destroys the boundary layer on the wall, which in turn , sharply intensifies heat transfer from this wall to the metal.

Heat is absorbed from the metal by an inert gas. The temperature of the metal is maintained at its melting point by changing the speed of movement of the inert gas, i.e. changes in the flow of the blower 13. If aluminum is used, the melting point of which is equal, the temperature of the wall in contact with the flue gases does not exceed 670 ° C. At the same time, it is the same at all points of the surface, since during melting the temperature of the metal is the same at all points. kah its volume. Due to the uniformity of the temperature fields, the thermal stresses in the walls of the afterburning chamber will be minimal, which increases the reliability of this chamber. The heated inert gas enters the heat exchanger 14, where it gives off its heat to the secondary air. The heated secondary air enters through the nozzle 19 into the duct 17, from which it flows through the nozzles 9 at a speed of 110-120 m / s into the afterburning chamber. The inert gas cooled in the heat exchanger 14 by the blower 13 na5

correct for heat transfer to the afterburner. When the thermal performance of the cyclone

The furnace changes the temperature of the flue gases in the afterburner. Despite this, due to the heat of the phase transition and the ability to vary the flow rate of the inert gas bubbling through

liquid metal in the interwall space 10, the temperature of the metal remains constant and equal to its melting point.

The proposed design provides an increase in the reliability of ka i afterburning due to high-intensity heat removal from its inner wall at a constant temperature, which minimizes thermal stresses due to the uniformity of temperature fields in the afterburning chamber, as well as the impossibility of increasing the temperature of this wall beyond the allowable temperature

Claims (2)

1. Cyclone furnace for burning wood dr. St. No. 1193367, characterized in that, in order to increase the reliability of the afterburning chamber, the afterburning space of the afterburner chamber is filled with metal and is provided in its upper part with an annular collector with vertical pipes made with open ends in the lower part of the burning chamber. 2. The furnace according to claim 1, differs from the fact that the open ends vertical pipes are made with a bevel towards the inner wall of the combustion chamber. / I A AT 5 2 Fig.Z