WO2010110634A2

WO2010110634A2 - Device and method for burning solid fuel

Info

Publication number: WO2010110634A2
Application number: PCT/LV2010/000003
Authority: WO
Inventors: Айгарс МУЙЖНИЕКС
Original assignee: Muiznieks Aigars
Priority date: 2009-03-27
Filing date: 2010-03-26
Publication date: 2010-09-30
Also published as: LV13994B; WO2010110634A3; LV13994A

Abstract

The invention relates to a burner running on solid organic fuel, and to a method for setting such fuel on fire. The invention can be used in boiler rooms and in other technological equipment for producing heat, and also for generating carbon monoxide. The proposed burner has a body (1) which is arranged in an upper part at the beginning of the burner, wherein lower air injectors (2) and a lower air entry (3) are arranged in the lower part of the burner at the exit thereof. Upper air injectors (8) are arranged in the upper part of the body (1) behind the lower air injectors (2). The proposed burner ensures optimum re-burning, owing to which the efficiency is increased and operational wastes are reduced. The proposed method is characterized in that the fuel (17) loaded into the body (1) of the burner is heated under the action of heat radiation from a flame in a fire tube (7) and the flame is moved to the end of the burner where air from the lower air injectors (2) is blown through an incandescent layer of fuel (17) and incomplete combustion takes place, wherein the gases which form are mixed with the air from the upper air injectors (8) where burning with a flame takes place.

Description

DEVICE AND METHOD FOR BURNING FUEL FUEL

The invention relates to a burner for solid fuel and a method of burning fuel, which is applicable in thermal installations of boilers, technological 5 devices or installations for generating carbon monoxide.

Three types of burners with automatic fuel supply are known, which are characterized by combustion with a flame in a fluidized bed or on the surface of the fuel.

The types of these burners are described in detail in the publication Wood Resolutions in Finland - Technology, Natural Market, Alakapg. E., Raju P. (Jūvakula VTT Solutions,

10 2002).

In the burners of the first type, fuel is poured on top of the grate, made in the form of plates. It is used in fireplaces. Resin problems are inherent in structures of this type and require frequent cleaning, since unheated granules quickly enter the combustion zone, which reduces the combustion temperature and 15 leads to the formation of resin.

In the burners of the second type, fuel is supplied from below, and a fuel slide is formed on which air is blown. Here the flaws are manifested when the combustion stops. In standby mode, tar is released, which, under the influence of the temperature of the coal from the lower layer of fuel, evaporates unburned and condenses on the heat exchange surfaces of the boiler. The flow of air from the burner sometimes blows particles of coal, and further operation of the burner does not ensure the burning of tar and coal deposited on the surfaces, so frequent maintenance is required.

In burners of the third type, horizontal fuel supply to

! 5 grates made in the form of an inclined floor, where air is supplied from below along the entire length of the burner. Upon reaching a temperature of 300 ^° C, volatile substances begin to burn when air is supplied to the surface, forming hardly combustible or non-combustible substances (products of complete combustion): carbon dioxide, water vapor and tar, thereby preventing useful secondary combustion in gases.

0 Burners of this type are described in patent applications EP2032896 (F23B40 / 06), “A burnet burner "and EP1950272 (C10JЗ / 30)," Method app daviso forrothermal оff resell оr wood chippings ".

In the above-mentioned devices, fuel is burned on the surface, they try to burn unburned products in the form of gases and vapors with the help of additional air and an elongated flame, however, in this combustible mixture there are many products of complete combustion or difficult to burn substances, for example, resins, therefore, combustion is often incomplete, and boiler room equipment must be cleaned of tarry deposits and soot.

The aim of the invention is the development of a burner that provides a complete process of secondary or final combustion without the formation of deposits, such as resins

SUMMARY OF THE INVENTION

The purpose of the invention is achieved by creating a burner for burning solid fuel (see the description of the design options of the burner in paragraphs 1-5 of the claims), which contains a housing and a loading hatch made in its upper part, with air in the upper part of the housing nozzles located above the fuel, and air nozzles located under the fuel are located in the lower part of the body or in the floor to form separate air flows above the fuel and under the fuel. The burner is characterized in that the air nozzles containing the air inlet located in the lower part of the housing are located at the end of the outlet. In addition, the floor located in the lower part of the housing is inclined, and this floor can be movable, further improving the progress of the fuel in the burner. In addition, in the upper part of the housing, behind the air nozzles located in the upper part of the housing, nozzles of oxidation air or upper air can be placed, this solution reduces the temperature in the zone of the nozzles. You can also use the loading hatch as the upper nozzle. This makes it possible to transport fuel together with the upper air, the supply of which is ensured by means of a pneumatic transport device equipped with an air duct, a dispenser, a fan and a tank. In addition to this, to achieve the objective of the invention, a method is developed (see the description of the process options in claims 6-10 of the claims) for burning solid fuel, characterized in that the fuel loaded into the burner body is heated by radiation of the heat of combustion of the flame, resulting in pyrolysis . The newly charged fuel moves the previously loaded heated fuel to the nozzles located in the lower part of the burner, from which the glowing layer of fuel is blown out, resulting in incomplete combustion. Gaseous substances and vapors formed as a result of incomplete combustion are mixed with the upper air, which was previously supplied from a loading hatch or nozzles, providing further combustion with a flame. In addition, when placing the upper nozzles closer to the end of the burner, the flame moves away from the fuel behind the lower nozzles. Moreover, if the fuel supply rate significantly exceeds the ability of the burner to burn all fuel, hot (heated) coals are emitted from the burner. In addition, the flame is led down through the coal bed, generating carbon monoxide and hydrogen. In addition, in order to generate “water gas” or “synthesis gas”, water vapor or water vapor together with oxygen is supplied to the acceptable level of stable combustion during the combustion process. Further, the invention is explained in more detail with reference to the accompanying drawings, in which: FIG. 1 - The first version of the burner.

FIG. 2 - The second version of the burner with an inclined floor and remote combustion. FIG. 3 - The third option of the burner is a gas generator.

FIG. 4 - The structure of the lower air nozzle.

FIG. 5 - Fuel supply mechanisms: a) directly to the burner, c) pneumatic transport;

1- burner body, 2- lower air nozzle, 3- lower air inlet, 4- fuel loading hatch, 5- burner floor, 6- ash, 7- heat pipe, 8- nozzles top air, 9- bunker, 10- screw conveyor, 11- air lock, 12- fan, 13- pneumatic transport pipeline, 14- vertical shaft, 15- grates, 16- exhaust gas exhaust pipe, 17- fuel, 18- coals . The burner (Fig. 1) contains a horizontal housing 1 with a flat floor 5 and a vault above it. In the initial part of the burner, a hatch 4 for loading granules is made from above, which is also used as input 8 of the upper air. In the floor at the end of the burner outlet nozzles are made for introducing lower air. The flame tube 7 from which the flame exits corresponds to the structural dimensions of the boiler equipment. The nozzles of the lower air 2 are made of ceramics and are connected by a metal pipe forming the input of the lower air 3.

The burner of this option works as follows: the supplied fuel enters the burner through the loading hatch 4, which also serves as an input 8 of the upper air, on the floor 5, the fuel 17 first receives heat from radiation from the combustion flame, and pyrolysis occurs; the newly loaded fuel through the loading hatch 4 moves the previously loaded heated fuel to the end of the burner, where the air nozzles 2 are located; the air stream provides combustion, and with an excess of fuel, gases and vapors mix with the upper air; at the flame tube 7, combustion begins with flame. This burner design has similarities with the third type of burners previously described, but there is a difference in the method of supplying lower air, which completely changes the design and results of combustion.

The second version of the burner for fuel with a high ash content (Fig. 2) comprises a horizontal housing 1 with an inclined floor 5 and its own above it. In the initial part of the burner, a hatch 4 for loading fuel is made from above, nozzles 2 for introducing lower air are made in the floor at the end of the burner outlet, from which air exits in the horizontal direction. The input pipe 8 of the upper air or oxidation air is connected to the flame tube 7. During combustion, the inclination of the floor 5 promotes the movement of fuel, the placement of the lower air nozzles 2 distributes the temperature concentration, at this leaves room for ash under the nozzles. The flame zone is removed by introducing the upper air through a separate inlet 8 of the upper air into the flame tube 7. This ensures the lowest possible temperature in the furnace and reduces the sintering of ash and slag in case of using low-quality fuel.

To the third variant of the burner - gas generator (Fig. 3) is attached a vertical shaft 14 with grates 15 for collecting coal 18 and an exhaust pipe 16 of the generator gases. The gas generator burner is characterized by the feed rate of granular fuel, which causes unburned, but already charred pellets to spill from the burner into the vertical shaft to the grate. The flame in the burner passes through a layer of coal and generates combustible gases.

The fuel loading into the furnace depending on the burner power and the amount of fuel is carried out using gravity, mechanical feed, or combining both of these feed options. Mechanical feeding is possible using a screw conveyor by introducing fuel through the loading door 4 or directly into the burner (fig. B), using a movable shutter through the loading door or directly into the burner, or using a pneumatic conveyor (fig. Δc), which is from the hopper ( 9) with the help of a screw conveyor and a rotary shut-off valve 11 doses the number of granules. The fan 12 transports the granules together with the upper air of the burner through the air duct 13 to the loading hatch.

Claims

CLAIM

1. A burner for burning solid fuel, comprising a housing (1) and a loading door (4), moreover, air nozzles (8) located above the fuel are placed in the upper part of the housing (1), and air nozzles are located in the lower part of the housing or in the floor (2) located under the fuel, for the formation of separate air flows above the fuel and under the fuel, characterized in that the air nozzles (2) located in the lower part of the housing containing the air inlet (3) are located at the end of the outlet.

2. The burner according to claim 1, characterized in that the floor (5) located in the lower part of the housing (1) is sloped, and the floor (5) can be movable.

3. A burner according to any one of claims 1 or 2, characterized in that the nozzles (8) of the upper air are located behind the air nozzles (2) located in the lower part of the housing (1).

4. Burner according to any one of paragraphs 1-3, characterized in that the air nozzles (8) located in the upper part are combined with a loading hatch (4).

5. The burner according to claim 4, characterized in that the fuel loading and the inflow of upper air are provided using a pneumatic air duct transport device, which is equipped with a container and a dispenser.

6. A method of burning solid fuel in a burner according to any one of claims 1 to 5, characterized in that the fuel (17) loaded into the burner body (1) is heated by radiation of the heat of combustion of the flame in the flame tube (7), moving the flame to the end of the burner, where, from the nozzles (2) located in the lower part, air is blown through the incandescent fuel layer (17) and incomplete combustion occurs, the gases formed are mixed with the air coming from the nozzles (8) located in the upper part, where there is combustion with the flame.

7. The method according to claim 6, characterized in that the nozzles (8) of the upper part are located behind the lower nozzles (2).

8. The method according to any one of claims 6 or 7, characterized in that the fuel feed rate significantly exceeds the ability of the burner to burn all fuel (17), and the flame of the flame tube (7) produces hot coals from the burner (18).

9. The method according to claim 8, characterized in that the flame of the flame tube (7) is taken down through a layer of coal (18), generating carbon monoxide and hydrogen.

10. The method according to claim 8, characterized in that during the combustion process, water vapor or water vapor and oxygen are brought to an acceptable level of stable combustion in order to generate a “water gas” or “synthesis gas”.