WO2006091061A1

WO2006091061A1 - Methods and devices for fuel combustion

Info

Publication number: WO2006091061A1
Application number: PCT/KZ2005/000006
Authority: WO
Inventors: Alexandr Klyuyev; Rafael Khizbullin
Original assignee: Alexandr Klyuyev; Rafael Khizbullin
Priority date: 2005-02-22
Filing date: 2005-08-24
Publication date: 2006-08-31
Also published as: EA200501428A1; EA008046B1

Abstract

This invention relates to fuel combustion and may be used in household appliances, heat power engineering, as well as in industries involved in waste incineration and waste utilization. In the methods of fuel combustion in accordance with the invention fuel and aircare fed via a fuel conduit (9) and air conduit (10) into a mixer (8) with generation of fuel-air mixture, which is fed into a chamber of combustion (1) where it is ignited, and the combustion products are subsequently taken off such to heat the walls of the combustion chamber. According to the invention the air is fed under pressure of 0.1-500 atmospheres and alternatively the airflow is expanded in diffuser section (12) of air conduit with its subsequent compression in confusor section (13) of air conduit (10) to accelerate the flow or the fuel conduit and the air conduit are arranged at the angle relatively to each other.

Description

METHODS AND DEVICES FOR FUEL COMBUSTION

TECHNICAL FIELD

This invention relates to fuel combustion and may be used in household appliances, heat power engineering, as well as for waste incineration and waste utilization.

BACKGROUND ART

There is widely known the method of fuel combustion in which a strongly swirling air flow is created in peripheral area of main combustion chamber in the form of peripheral whirlwind exciting within paraxial area of main combustion chamber a paraxial whirlwind contra-flowing to it and rotating in the same direction, and additionally a strongly swirling air flow is created in primary chamber of combustion where a flow of air-fuel mixture is generated and then ignited and burned in primary chamber, and afterburning and dilution of combustion products from primary chamber of combustion are performed in paraxial whirlwind air flow of main chamber of combustion, the combustion products of paraxial whirlwind exiting and peripheral whirlwind being formed within the same section, which is perpendicular to the axis of peripheral and paraxial whirlwinds, at that, to generate the air-fuel mixture flow in primary chamber of combustion a strongly swirling active flow is created, forming in the plane of its formation, a flow pattern with high radial gradient of static pressure in the capacity of which is used a fuel fed into a central area of created active flow due to formation of a high axial gradient of static pressure by a high radial gradient of static pressure.

The device for embodiment of the above-mentioned method comprises the main chamber of combustion consisting of the flue tube, a secondary air supply mechanism, the swirler and conduit of combustion products taking-off which are arranged in the same section and perpendicularly to the central axis of the chamber of combustion, as well as the primary chamber of combustion comprising the flue tube, facilities of fuel and primary air supply, the swirler and igniter, the primary chamber of combustion being located in the front of the main chamber of combustion and coaxially to the latter, at that, the flue tubes of chambers of combustion are connected, the fuel supply unit and swirler of primary chamber of combustion, performed in the form of swirling nozzle block, are located on its front end face in the section perpendicular to the central axis of the chamber of combustion while the primary air supply facility is performed in form of the nozzle and it is located in swirling nozzle block ( RF patent No.2212003, cl. F23R 3/00, 2003).

The generation of two strongly swirling airflow complicates the implementation of the method of combustion and requires to use a complex device which shall be equipped with swirling mechanism and additional chambers.

There is widely known the method of fuel combustion comprising fuel and air supply via fuel and air conduits into the mixer, at that, the fuel-air mixture is generated and then it is fed into the chamber of combustion and ignited. The air flow is separated into the central and peripheral swirling flows which are mixed with formation of circulating areas and then the fuel is fed into these areas, the whirlwind flow coming out from the area of combustion is accelerated due to the transformation of kinetic energy of rotary motion into a potential energy of pressure, and then it is diluted by additional masses fed at the beginning of the acceleration process, and, concurrently with dilution and acceleration, it is after-burned. The device of fuel combustion comprises a chamber of combustion with igniting element, a fuel feeder, an air feeder and a mixer provided with fuel and air conduits. The fuel feeder is located in the center of the vane swirler (RF patent No. 2215941, Cl. F23R 3/00, 2003).

The necessity to generate central and peripheral swirling flows and mix them with formation of circulating areas and additional acceleration of whirlwind flow make the method and device design very sophisticated. To generate the whirlwind it is necessary to provide the device having significant available volume that gives rise to its metal and power intensities leading to reduced efficiency of such device, at that, eventual environment pollution with products of incomplete fuel combustion being not prevented.

DISCLOSURE OF INVENTION

This invention is intended to develop a pollution-free method and device of combustion of gas fuels, fuel oils and particulate solid fuels.

The technical results of this invention consisting in improving device efficiency, easing method and device design, reducing metal and power intensities, are achieved through the effect that in process of fuel combustion under the first alternate embodiment of this invention comprising fuel and air feed via fuel and air conduits into the mixer with generation of fuel and air mixture which is fed into the chamber of combustion where it is ignited, and the combustion products are subsequently taken off, the air is fed under pressure of 0.1 - 500 atmospheres and then the flow is expanded in a diffuser section of air conduit with its subsequent compression in a confusor section of air conduit to accelerate the flow and then it is mixed with fuel at the point of their convergence within one area of mixing duct, and at that the products of combustion taken-off heat the walls of the chamber of combustion. The taken-off combustion products are partially fed into the chamber of combustion where they are after-burned.

The solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously. If necessary, an oxidant is fed into a chamber of combustion.

The device of fuel combustion in accordance with the first alternate embodiment of this invention, comprising a chamber of combustion with igniting element, a fuel feeder, an air feeder, a flue duct with conduits for combustion products taking-off and air feeding, as well as a mixer provided with fuel and air conduits, under this invention, is equipped with a mixing duct, while the air conduit has diffuser and confusor sections, the fuel conduit has a confusor section which is performed on the outside of the confusor section of air conduit, and the confusor sections of air and fuel conduits form air and fuel jets located in the front of mixing duct, and the flue duct is located on the outside of the chamber of combustion.

The holes in the walls of the chamber of combustion are provided to feed combustion products from the flue duct into the chamber of combustion.

The device may be provided with at least one extra fuel feeder, an oxidant feeder and oxidant conduit having a confusor section which is performed on the outside of a confusor section of fuel conduit.

In the process of fuel combustion conforming to the second alternate embodiment of this invention comprising fuel and air feed via fuel and air conduits into a mixer with generation of fuel and air mixture which is fed into a chamber of combustion where it is ignited and the combustion products are subsequently taken off, under this invention, the fuel and air are fed under pressure of 0.1 - 500 atmospheres, and then the air flow is compressed and accelerated within an outlet section of air conduit, at that, the combustion products taken-off heat the walls of the chamber of combustion. The combustion products taken-off are partially fed into the chamber of combustion where they are after-burned.

The solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously. If necessary, an oxidant addition is fed. The device of fuel combustion in accordance with the second alternate embodiment, comprising a chamber of combustion with an igniting element, a fuel feeder, an air feeder, a flue duct with conduits for combustion products taking-off and for air feeding, as well as a mixer provided with fuel and air conduits, under this invention, the fuel conduit in its cross-section is shaped as an annular and the air conduit is- located on the outside of the fuel conduit and coaxially to the latter, the outlet section of air conduit being performed as a confusor and the flue duct being located on the outside of the chamber of combustion.

The device is provided with at least one extra fuel feeder and an oxidant feeder equipped with oxidant conduit connected to the air conduit.

In process of fuel combustion conforming to the third alternate embodiment of this invention comprising fuel and air feed via fuel and air conduits, arranged at the angle relatively each other, into a mixer with generation of fuel and air mixture which is fed into a chamber of combustion where it is ignited, and the combustion products are subsequently taken off, under this invention, the air is fed under pressure of 0.1 - 500 atmospheres, and, at that, the combustion products taken-off, heat the walls of the chamber of combustion.

The combustion products taken-off are partially fed into the chamber of combustion where they are after burned.

The solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously. The device of fuel combustion in accordance with the third alternate embodiment, comprising a chamber of combustion with an igniting element, a fuel feeder, an air feeder, a flue duct with conduits for combustion products taking-off and for air feeding, as well as a mixer provided with fuel and air conduits which are arranged at the angle relatively each other, under this invention, the flue duct is located on the outside of the chamber of combustion.

The device is provided with at least one extra fuel feeder.

The air feeding under pressure of 0.1 - 500 atmospheres and air flow expansion with its subsequent compression and acceleration in accordance with the first alternate embodiment of this invention make possible to achieve the required depression degree within the area of air flow coming-out from a confusor section via an air jet that promotes the intensive fuel injection into a confusor section of fuel conduit and further via a fuel jet into a mixing duct.

The arrangement of confusor sections of air and fuel conduits which form air and fuel jets in the front of mixing duct gives rise to increased rates of air and fuel flows due to the potential energy transformation into kinetic energy, each of these flows being injected at a high rate into a mixing duct to generate fuel-air mixture. To obtain a finely dispersed mixture with optima fuel-air ratios the said flows shall converge within one limited area (point). Provided that the condition of output flows convergence within one area of mixing duct is fulfilled, then the generated fuel-air mixture is burned completely without formation of carbon black and carbon oxides. That leads to improving device efficiency.

The feed of fuel and air, in accordance with second alternate embodiment of this invention, into a mixer by coaxial flows and air flow compression and acceleration within an outlet section of air conduit make possible to achieve the required depression degree within an area of air flow coming-out from the confusor section that promotes the intensive fuel injection and finely dispersed mixture production. The air feeding under pressure of 0.1 - 500 atmospheres makes possible to provide necessary conditions to disperse the fuel-air mixture. The heating of the walls of the chamber of combustion in accordance with all alternate embodiments of this invention gives rise to increased operating temperature in the chamber of combustion and effective fuel combustion that leads to reducing power intensity of the device and improving its efficiency. In operations of the said alternate embodiments of this invention it is not required to generate whirlwind flows that allows to significantly reducing its volume and metal intensity.

The pressure under which the air is fed depends on fuel type, its viscosity and temperature. If the gas fuel is used, then the pressure may be minimal - 0.1 atmospheres. The fuel viscosity increases, the air pressure shall increase respectively. If heavy hydrocarbons or solid fuel are used as a fuel for this device, then the air is fed under pressure of 500 atmospheres.

Due to air feeding under pressure and chamber of combustion heating with exhaust flows the operating temperatures in the chamber of combustion reach over 1500⁰C, therefore it is necessary to manufacture it using heat- resistant materials.

Every of the said alternate embodiments of this invention may be provided with stand-alone units of air and fuel heating. Moreover, air and fuel may be heated with gases exhausting from the furnace.

BRIEF DESCRIPTION OF DRAWINGS

This invention is explained with the following drawings, in which Figure

1 is a longitudinal section of the first alternate device embodiment of this invention; Figure 2 is a longitudinal section of the second alternate device embodiment of this invention; Figure 3 is a longitudinal section of the third alternate device embodiment of this invention.

ALTERNATE EMBODIMENTS OF THE INVENTION

The device of fuel combustion in accordance with the first alternate embodiment of this invention comprises a chamber of combustion 1 with an igniting element 2, a fuel feeder 3, an air feeder 4, a flue duct 5 with conduits for products of combustion taking-off 6 and conduits for air feeding 7, as well as a mixer 8 provided with a fuel conduit 9 and an air conduit 10, and a mixing duct 11. The air conduit 10 has a diffuser section 12 and a confusor section 13 and the fuel conduit has a confusor section 14 which is performed on the outside of the confusor section of air conduit, while the confusor sections 13 and 14 of air and fuel conduits form air and fuel jets located in the front of mixing duct 11, and the flue duct 5 is located on the outside of the chamber of combustion 1.

The holes 15 in the walls of the chamber of combustion 1 are provided to feed combustion products from the flue duct 5 into the chamber of combustion 1.

The device may be provided with at least one extra fuel feeder 16. The conduits 6 for combustion products taking-off are communicating with a heat exchanger (not shown). For subsidiary air supply into the chamber of combustion additional conduits (not shown) may be provided. The device may be equipped with an oxidant feeder 17 and oxidant conduit having a confusor section 18, which is performed on the outside of a confusor section of fuel conduit 9. The device of fuel combustion in accordance with the second alternate embodiment of this invention comprises a chamber of combustion 1 with an igniting element 2, a fuel feeder 3, an air feeder 4, a flue duct 5 with conduits 6 for products of combustion taking-off and conduits 7 for air feeding, as well as a mixer 8 provided with a fuel conduit 9 and an air conduit 10. The fuel conduit 9 in its cross-section is shaped as an annular and an air conduit 10 is located on the outside of fuel conduit 9 and coaxially to the latter, the outlet section 11 of air conduit 10 being performed as a confusor and the flue duct 5 being located on the outside of the chamber of combustion 1. The holes 12 in the walls of the chamber of combustion 1 are provided to feed combustion products from the flue duct 5 into the chamber of combustion 1.

The device is provided with at least one extra fuel feeder (not shown) and an oxidant feeder 13 with oxidant conduit 14, which is connected to the air conduit 10.

The device of fuel combustion in accordance with the third alternate embodiment of this invention, comprising a chamber of combustion 1 with igniting element 2, a fuel feeder 3, an air feeder 4, a flue duct 5 with conduits 6 for combustion products taking-off and conduits 7 for air feeding, as well as a mixer 8 provided with fuel conduit 9 and air conduit 10 which are arranged at the angle relatively each other. The flue duct 5 is located on the outside of the chamber of combustion 1.

The holes 11 in the walls of the chamber of combustion 1 are provided to feed combustion products from the flue duct 5 into the chamber of combustion 1.

The device is provided with at least one extra fuel feeder (not shown) and one extra air conduit (not shown). Every of the said alternate embodiments of this invention may be provided with stand-alone units of air and fuel heating (not shown). Moreover, the air and fuel may be heated with gases exhausting from the furnace.

The first alternate embodiment of the method and device operation in accordance with this invention are implemented as follows:

The gas fuel is fed by a fuel feeder 3 and the air is fed by an air feeder 4, for example by a compressor, via a fuel conduit 9 and an air conduit 10, respectively, into a mixer 8 with generation of a fuel-air mixture which is fed into a chamber of combustion 1 and then it is ignited with an igniting element 2, for example, with electric-arc igniter. The air is fed under pressure of 0.1 atmospheres and then the airflow is expanded within a diffusion section 12 of air conduit and compressed within a confusor section 13 of air conduit to accelerate the airflow. The required depression degree is achieved within the area of air flow coming-out from the confusor section 13 forming an air jet at the outlet end that promotes the intensive fuel injection into the confusor section 14 of fuel conduit and further through a calibrated orifice at the end of section 14, which forms a fuel jet, into a mixing duct 11.

The fuel and air mixing is proceeded at provided convergence of coming out fuel and airflows within one area of mixing duct 11. The fuel consumption is regulated with flow control valve (not shown) in the manner that the optimal fuel-air ratios are achieved. It is determined visually from the flame color, which shall be blue. If so, the under-burning is reduced and high device efficiency is achieved. The control of fuel consumption may be performed in automatic mode with a regulator device (not shown), which is connected to a gas-analyzer located on the exhaust outlet for combustion products.

The combustion products are taken-off via a flue duct 5 which is located on the outside of the chamber of combustion, at that, the hot exhaust gases heat the walls of the chamber of combustion. It gives rise to increased operating temperatures in the chamber of combustion and allows improving the device efficiency.

The taken-off combustion products may be partially fed via the orifices

15 into the chamber of combustion where they are after-burned. A supplementary air is supplied via the air tubes 7 to improve efficiency of fuel- air mixture afterburning.

The combustion products from the flue duct are fed via the tubes 7 into the heat exchanger (not shown).

The air fed to the conduit 10 may be heated to any required temperature, for example to over 100° C, and, if so, when additional fuel oils are fed, they evaporate, and the generated fuel-air mixture, being in gaseous state, enters into the chamber of combustion that improves the completeness of fuel combustion and device efficiency. For these purposes an extra fuel feeder 16 is provided. The longitudinal partitions (not shown) may be provided in a fuel conduit 9 that makes possible to transport the fuel flow from each device 3 and

16 via a respective sector to the point of its mixing in a mixer 11. This improves the device flexibility and does not require its re-equipment in cases of changes-over from one fuel to another. In process of heavy-hydrocarbon fuels combustion an oxidant is added with a feeder 17 via a conduit having a confusor section 18. Oxygen, ozone or other components are used as oxidants.

The operation of second alternate device embodiment in accordance with this invention is implemented as follows:

The gas fuel, fuel oil or particulate solid fuel is fed by a fuel feeder 3 and the air is fed by an air feeder 4, for example by a compressor, via a fuel conduit 9 and an air conduit 10, respectively, into a mixer 8. The fuel and air are fed into a mixer 8 in form of coaxial flows, the air being fed under pressure of 20 atmospheres, and then the airflow is compressed and accelerated within an outlet section 11 of air conduit 10. At airflow coming-out via a jet, provided at the outlet of section 11, the fuel coming out from the fuel jet provided at the outlet of conduit 9, is injected at high rate, and fuel and air are mixed with generation of finely dispersed mixture. If necessary, the air is heated to the temperatures varying from 50 ° C to 1000 ° C. The gases generated in result of fuel-air mixture combustion are taken-off to a flue duct 5, at that heating the walls of the chamber of combustion 1, and then the combustion products are fed into a heat exchanger (not shown) via a gas-analyzer (not shown).

The taken-off combustion products are partially fed via the orifices 12 into the chamber of combustion where they are after-burned.

The solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels may be supplied simultaneously. For these purposes a supplementary fuel feeder (not shown) is provided. The fuel consumption is regulated visually from the flame color or in automatic mode, depending on the exhaust gases composition.

If the device is equipped with an oxidant feeder 13, then the oxygen, ozone or other oxidants are fed via a conduit 14 into an air conduit 10 to improve the efficiency of fuel combustion.

The third alternate embodiment of the method and device operation in accordance with this invention are implemented as follows: The solid and viscous fuel oil is fed by a feeder 3 and air is fed under pressure of 500 atmospheres by a feeder 4 via a fuel conduit 9 and air conduit 10 arranged at the angle relatively each other and via a fuel jet and an air jet provided on the outlet ends of conduits 9 and 10 and then into a mixer 8 with generation of fuel-air mixture which is fed into the chamber of combustion 1 where it is ignited. A glover filament or electrodes between which an electric arc is initiated may be used as an igniting element 2, also, the said element 2 may be an electric-spark element. To control the process of fuel-air mixture combustion an air augmented feed is supplied via tubes 7. The gas combustion products are taken off via a flue duct 5, at that, they heat the walls of chamber of combustion 1 giving rises to increased operation temperature in the chamber of combustion.

If necessary, the taken-off combustion products are partially fed into the chamber of combustion 1 through the orifices 11 for their afterburning and the air is heated to 500⁰C.

An augmented feed of fuel oils or gas oils may be supplied. For these purposes a supplementary fuel feeder (not shown) is provided. The fuel consumption is regulated visually from the flame color or in automatic mode, depending on the exhaust gases composition passed through a gas-analyzer.

INDUSTRIAL APPLICABILITY

The proposed alternate device embodiments may be used in processes of fuel combustion and to generate heat energy and electricity by the power plants, in industries of waste incineration and utilization, as well as in facilities where the energy of compressed gas is transformed in a shaft-mechanical work of gas turbine, at that the energy of gas combustion products being partially consumed to compressing air in the compressor and remaining energy may be transmitted to the driving unit of gas turbine engine. The proposed devices may be used in domestic stoves for room heating and hot water supply.

High temperatures over 1500 ⁰C achieved at fuel combustion make possible to use the proposed devices in metallurgy, petrochemistry and construction materials production. In process of the proposed devices operation a complete fuel afterburning is achieved without formation of toxic components. Moreover, the toxic substances fed are completely neutralized. So that, the proposed devices allow to processing toxic and poisonous substances which are transformed in absolutely neutral components in result of thermal treatment. The proposed devices are manufactured of heat-resistant materials, for example, of heat-resistant steel or iron. The highly heat-stressed parts are manufactured of bronze or fluoroplastic.

Claims

1. A method of fuel combustion comprising a feed of fuel and air via a fuel conduit (9) and an air conduit (10) into a mixer (8) with generation of fuel-air mixture, which is fed into a chamber of combustion (1), and then it is ignited, the combustion products being subsequently taken off, characterized in that the air is fed under pressure of 0.1 - 500 atmospheres and then the airflow is expanded within a diffusion (12) section of air conduit and then it is compressed within a confusor (13) section of air conduit to accelerate the said airflow with its subsequent mixing with a fuel within an area of convergence of coming-out fuel and air flows in the mixing tube, at that the combustion product being taken off heat the walls of a chamber of combustion (1).

2. The method of claim 1, characterized in that the combustion products taken off are partially fed into a chamber of combustion (1) for their afterburning.

3. The method of claim 1 or claim 2, characterized in that the solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously.

4. The method of claim 1, claim 2 or claim 3, characterized in that an oxidant is additionally fed into a mixer (8).

5. A device of fuel combustion comprising a chamber of combustion (1) equipped with an igniting element (2), a fuel feeder (3), an air feeder (4), a flue duct (5) provided with conduits to take-off combustion products (6), a mixer (8), having a fuel conduit (9) and an air conduit

(10), characterized in that the said device is equipped with a mixing tube (11), an air conduit (10) has diffusion (12) and confusor (13) sections, a fuel conduit has a confusor section (14), provided on the outside of a confusor section of air conduit, while confusor sections (13) and (14) of air conduit and fuel conduit form fuel and air jets, located in the front of the mixing tube (11), and a flue duct (5) is located on the outside of a chamber of combustion (1).

6. The device of claim 5 characterized in that the orifices (15) are performed in the walls of the chamber of combustion (1) to feed combustion products from the flue duct (5) into the chamber of combustion (1).

7. The device of claim 5 or claim 6, characterized in that it is equipped with at least one extra fuel feeder (16).

8. The device of claim 5, 6 or claim 7, characterized in that it is equipped with an oxidant feeder (17) and an oxidant conduit having a confusor section (18), provided on the outside of the confusor section of fuel conduit (9).

9. A method of fuel combustion comprising a feed of fuel and air via a fuel conduit (9) and air conduit (10) into a mixer (8) with generation of fuel-air mixture, which is fed into a chamber of combustion (1), and then it is ignited, the combustion products being subsequently taken off, characterized in that the fuel and air are fed into a mixer (5) in a form of coaxial flows, the airflow being fed under pressure of 0.1 - 500 atmospheres, and then the airflow is expanded and accelerated at the outlet section of air conduit, while the combustion products taken off heat the walls of a chamber of combustion (1).

10. The method of claim 9, characterized in that the combustion products taken-off are partially fed into the chamber of combustion to afterburning.

11. The method of claim 9 or claim 10, characterized in that the solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously.

12. The method of claim 9, claim 10 or claim 11, characterized in that an oxidant addition is fed into a mixer.

13. A device of fuel combustion comprising a chamber of combustion (1) equipped with an igniting element (2), a fuel feeder (3), an air feeder (4), a flue duct (5) provided with conduits (6) to take-off combustion products, a mixer (8), having a fuel conduit (9) and an air conduit (10), characterized in that the fuel conduit (9) in its cross-section is shaped as an annular, and air conduit (10) is located on the outside of fuel conduit (9) coaxially to it, the outlet section (11) of air conduit (10) is performed as a confusor and a flue duct (5) is located on the outside of a chamber of combustion (1).

14. The device of claim 13, characterized in that the orifices (12) are performed in the walls of the chamber of combustion (1) to feed combustion products from the flue duct (5) into a chamber of combustion (1).

15. The device of claims 13 or 14, characterized in that it is provided with at least one extra fuel feeder.

16. The device of claims 13, 14 or 15, characterized in that it is provided with an oxidant feeder (13) equipped with oxidant conduit (14) connected to the air conduit (10).

17. A method of fuel combustion comprising a feed of fuel and air via a fuel conduit (9) and air conduit (10) arranged at the angle relatively each other, into the mixer (8) with generation of fuel and air mixture which is fed into the chamber of combustion (1) where it is ignited and the products of combustion are subsequently taken off, characterized in that the air is fed under pressure of 0.1 - 500 atmospheres, and at that, the combustion products taken off heat the walls of a chamber of combustion (1).

18. The method of claim 17, characterized in that the combustion products taken off are partially fed into a chamber of combustion (1) for their afterburning.

19. The method of claim 17 or claim 18, characterized in that the solid fuels and fuel oils or solid fuels and gas fuels, or fuel oils and gas fuels are supplied simultaneously.

20. A device of fuel combustion comprising a chamber of combustion (1) equipped with an igniting element (2), a fuel feeder (3), an air feeder

(4), a flue duct (5) provided with conduits (6) to take-off combustion products, a mixer (8), having a fuel conduit (9) and an air conduit (10), arranged at the angle relatively each other, characterized in that a flue duct (5) is located on the outside of a chamber of combustion.

21. The device of claim 20, characterized in that the orifices (11) are performed in the walls of the chamber of combustion (1) to feed combustion products from the flue duct (5) into the chamber of combustion (1).

22. The device of claim 20 or claim 21, characterized in that it is equipped with at least one extra fuel feeder.