WO2010151094A1

WO2010151094A1 - Solid fuel combustion method and device

Info

Publication number: WO2010151094A1
Application number: PCT/KZ2009/000020
Authority: WO
Inventors: Жиргалбек Омуралиевич САРЫМСАКОВ; Талгат Векузакович ТУРСУНОВ
Original assignee: Sarymsakov Jirgalbek Omuralievitch; Tursunov Talgat Bekuzakovitch
Priority date: 2009-06-24
Filing date: 2009-11-19
Publication date: 2010-12-29
Also published as: EA016403B1; UA96798C2; EA200900895A1; CN102997225A; TR201000815A1

Abstract

The solid fuel combustion method and device relate to the field of thermal power engineering, namely to furnace devices with a one-way forced air feed, and can be used for heating buildings and structures, incinerating waste and burning solid combustion materials in thermoelectric power stations, etc. The method for combusting solid fuel involves feeding a fuel and air into a combustion zone, discharging the flue gases into the atmosphere via a heat exchanger and discharging the solid residues into an ash collector. A fire bed is formed in the combustion zone, the fuel and air are fed from top to bottom, an excess pressure is generated in a combustion chamber, the flue gases and solid combustion products are removed from the combustion zone via a fire bar into an ash chamber and the combustion gases are then discharged into the heat exchanger. The device for combusting solid fuel comprises a bin for solid fuel with a device for feeding the fuel and air into a furnace, a furnace consisting of a combustion chamber, a heat exchange chamber that is provided with a heat exchanger and communicates with a flue, and an ash chamber with an ash collector. The combustion chamber comprises channels for feeding the fuel and air into a hearth section and a fire bar in the bottom section, said combustion chamber being accommodated with a circular clearance in the ash chamber, which communicates with the heat exchange chamber. The technical result is an increase in solid fuel combustion efficiency and a reduced ash content and toxicity of the recoverable flue gases.

Description

METHOD FOR BURNING A SOLID FUEL AND A DEVICE FOR ITS IMPLEMENTATION

The invention relates to the field of power engineering, in particular to methods of burning solid fuel and furnace devices with unilateral forced blowing and can find application in heating buildings and structures with solid fuel.

A known method of burning and dry distillation of solid fuel (RF patent Xe 2319065, F23BЗО / OO, publ. March 10, 2008), which includes placing a portion of fuel in a chamber, heating it to a volatile exit temperature, separating vapor and solid phases and burning the latter in the furnace, and before placing the fuel in the chamber, it is heated from the inside above the temperature at which the bulk of the volatile substances is released, and the placement of fuel in the chamber is accompanied by its impact on the chamber walls.

The disadvantage of the described method of burning solid fuel is its complexity due to the multi-operation preparation of fuel for the combustion phase. Closest to the claimed is a method of burning solid fuel and a device for its implementation (RF patent JVa 2294483, F 23B 40/00, F 23C 5/08, publ. 27.02. 2007).

According to this method, before burning, the fuel is sorted into predetermined sizes or granulated. Fuel and air are fed into the combustion zone according to a predetermined algorithm that ensures the power of the furnace and the completeness of fuel combustion. The gas residues of combustion are discharged into the atmosphere through a heat exchanger, and the solid residues are transferred to an ash collector. Fuel is supplied to the combustion zone along with air from the bottom up. Solid residues, slag and ash are automatically removed from the combustion zone by fuel and air supplied to it, which are heated by the upper layers of slag and ash. The time between periods of fuel supply to the furnace is determined from the dependence so that the solid residues formed are replaced in a timely manner with new fuel. A device for implementing this method of burning solid fuel, contains a hopper for solid fuel, a heat exchanger, a furnace, a device for supplying fuel and air to the furnace, an ash collector, a control unit (controller), temperature sensors, electric drives, and a vertical burner made in the form of a truncated cone shell with holes for pumping air and connected by a narrow side with a device for supplying fuel and air, which is a manifold connected to a fan. In this case, the fuel supply device is equipped with a screw conveyor, part of the pipe of which is located in the manifold, equipped with openings for air.

The disadvantages of the described method of burning solid fuel and a device for its implementation are the low efficiency of the combustion process, since the lower supply of fuel to the furnace with air and the direct exit of pyrolysis gases through a chimney made in its ceiling part do not allow creating a constantly burning layer for complete combustion portioned fuel, which entails increased ash and toxicity of utilized flue gases.

The aim of the invention is to increase the efficiency of burning solid fuel, while reducing the ash content and toxicity of utilized flue gases.

The problem is solved due to the fact that in the method of burning solid fuel, fuel and air are supplied to the combustion zone from top to bottom according to a predetermined algorithm that provides optimal furnace power and completeness of fuel combustion, while the burning layer and overpressure are preliminarily created in the combustion zone, and the discharge flue gases are carried out from under the combustion zone, and flue gases before leaving the atmosphere is passed through a heat exchanger, and solid residues under the influence of gravity and excess pressure in the combustion zone enter the ash pan.

A device for implementing the proposed method for burning solid fuel, contains a hopper for solid fuel with a device for supplying fuel and air to the furnace, a heat exchange chamber with a heat exchanger and connected to the chimney, a furnace consisting of a combustion chamber with a fuel and air supply channel in the hearth and a grate in the bottom, ash chamber with an ash pan, a control unit for supplying fuel and air, and the combustion chamber is placed with an annular gap between its outer surface and the housing of the device in the ash chamber Leray, whereby the ash chamber communicates with the heat exchange chamber.

The supply to the combustion zone of fuel with air from top to bottom on a previously created burning layer creates conditions for the intensive formation of pyrolysis gases, which, passing through the burning layer under excessive pressure and mixed with air oxygen, form a combustible gas under the grates, during the combustion of which heat is generated, providing maintaining a stable state of the burning layer and the complete combustion of all volatile substances, which entails a marked reduction in ash and harmful emissions. Thus, the emission of flue gases from under the combustion zone contributes to intensive heat transfer in the heat exchanger and reduces the toxicity of the exhaust gases. A device for burning solid fuel is illustrated in FIG. 1, where a schematic overview of a device is shown.

A device for burning solid fuel contains a hopper 1 (manual loading is possible) for solid fuel, a device 2 for supplying fuel and air to the furnace, a heat exchange chamber 3 with a heat exchanger 4, communicating with the chimney 5. The furnace consists of a combustion chamber 6, channels 8 and 9 in the hearth for supplying fuel and air, respectively (Fig. 1 shows variant with combined channels 8 and 9), and a grate 10 is installed in its bottom part. Combustion chamber 6 is placed with an annular gap in the ash chamber 11 with an ash pan in the lower part. The ash chamber 11 communicates with the heat exchange chamber 3 through an annular gap between the outer wall of the furnace and the housing. The combustion chamber can be equipped with a sealed door 7, providing access to the combustion chamber to accommodate the initial portion of the fuel and fuel, as well as for maintenance of the furnace.

The device 2 for supplying fuel and air to the furnace can be equipped with a control unit of any known design, for controlling the supply of air and fuel. The method of burning solid fuel is implemented as follows. In the combustion chamber 6 on the grate 10, a burning layer is preliminarily created, for example from burning dry firewood, to which atmospheric air is forcibly supplied through channel 9, and solid fuel is fed portionwise through channel 8 from bunker 1. In the combustion chamber 6 creates excessive pressure at which solid fuel ignites from the high temperature of the burning layer and releases pyrolysis gases. Pyrolysis gases under pressure pass through the burning layer and the grate 10 is connected in the ash chamber 11 with atmospheric oxygen that has not reacted, and form combustible gases. Combustible gases during combustion under the grate emit a large amount of heat, which maintains a stable state of the burning layer, ensures the combustion of toxic volatile products and the combustion of solid fuel particles. At the same time, solid combustion products and unburned fuel residues passing through the grate 10 are deposited in the ash pan. The flue gases from the ash chamber 11 enter the heat exchange chamber 3, giving off heat to the heat exchanger 4, are cooled and emitted through the chimney 5 into the atmosphere. The process of firing up the initial portion of the fuel (especially in the case of using fuel requiring a high ignition temperature) can be carried out by loading this portion as directly from the hopper 1 through channel 8, and through a special door 7.

The use of the control unit allows you to automate and optimally configure the process of supplying air and fuel, depending on the selected type of combustible material.

The invention allows to create an environmentally friendly, almost smokeless method of burning solid fuel while increasing its combustion with a high coefficient of heat generation and heat transfer, and also simplifies the design of the furnace and increasing its efficiency with increasing degree of thermal decomposition of fuel, which reduces the amount of harmful emissions into the atmosphere.

The proposed invention can find the widest application, since it does not require preliminary preparation of fuel, it provides efficient combustion of almost any kind of combustible materials and their mixtures, including household waste.

Claims

CLAIM

1. A method of burning solid fuel, in which fuel and air are fed into the combustion zone, the gas residues of the combustion are discharged into the atmosphere through a heat exchanger, and the solid residues are collected in an ash collector, such as in the zone Combustion preliminarily creates a burning layer, fuel with air is supplied from top to bottom, overpressure is created in the combustion chamber, gaseous and solid combustion products are removed from the combustion zone through the grate to an ash chamber, then the gaseous combustion products are removed to the heat exchanger.

2. The device for implementing the method according to claim 1, containing a hopper for solid fuel with a device for supplying fuel and air to the furnace, a furnace consisting of a combustion chamber, a heat exchange chamber with a heat exchanger in communication with a chimney, an ash chamber with an ash collector, about l Moreover, in that the combustion chamber contains fuel and air supply channels in the hearth and the grate in the bottom, the combustion chamber is placed with an annular gap in the ash chamber in communication with the heat exchange chamber.