RU2446359C1 - Furnace fuel combustion method - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: furnace fuel combustion method is proposed, mainly for domestic furnace containing housing with a door for fuel loading, in which there made are air supply channels to combustion chamber with combustion zone, channels for removal of fuel combustion products from combustion chamber, and stack for removal of combustion products. Method consists in fuel laying in furnace combustion zone with its further ignition, combustion with heat release, obtaining of combustion products themselves with further heat removal from combustion products by means of their warming-up of heating elements of furnace and removal of the above combustion products through stack. The main flow of combustion products is separated at least into two additional intermediate flows by installing on the way of the main flow of shaped wall with openings, mainly in its peripheral zone, and the obtained additional intermediate flows are supplied through the above openings to furnace walls. Each additional intermediate flow is turned and passed along furnace walls in its part located in close proximity to the stack; then, additional intermediate flows are turned, mainly all of them, at least once, towards each other and swirling movement is given to each flow, mainly along spiral; then, additional intermediate swirling flows are mixed between each other and the obtained swirling flow is supplied to stack.

EFFECT: improving fuel combustion completeness and furnace heating capacity and increasing service life of its operation at constant fuel consumption.

4 cl, 4 dwg

Description

The invention relates to methods for providing fuel combustion in furnaces and can be used in the development of furnaces and heating devices for cooking and heating a room.

Known incinerator sectional structure containing a direct closed pipe with holes located along its length, which is designed to supply air to the furnace. The air supply pipe is inserted into the furnace through an opening made in the upper part of the furnace. Air is supplied to the pipe by a fan. Air flows through the openings of the pipe and is involved in the intensive combustion of fuel, in this case debris (patent EP 0636840 A1, IPC: F24B 1/00, 5/00).

This method of supplying and distributing air in the combustion chamber and the combustion device are suitable for safe and intensive burning of garbage, but ineffective for long-term economical combustion of fuel.

Known firebox for burning granular solid fuels and heating indoor air. The furnace consists of a combustion chamber, in its center an inserted air supply pipe and a screw device. Air is supplied to the combustion chamber using a fan from above, and granular fuel is loaded from below from a screw device (US Pat. No. 4,782,765, IPC: F24B 1/00, 5/00).

The design of such a firebox is complex and not suitable for burning wood.

A known method of supplying and distributing air in the combustion chamber, when air is supplied to the combustion chamber from above through the pipe, the pipe ends with an air distributor based on fuel and with the pipe dropping down when the amount of fuel in the combustion chamber decreases, and the air in the combustion chamber distributed as follows: 40-60% are supplied to the combustion center; 10-30% are fed to the edges of the combustion zone; above the combustion site - 20-40%. (Patent EP 005303, Application No. 200301136 of 04.19.01, IPC: F24B 1/00, 5/00).

The disadvantages of this method is that on the pipe supplying air to the combustion zone, it is necessary to install an air distributor and move it during the combustion process. This leads to a complication of the design of the combustion chamber and the deterioration of the conditions of its operation due to the fact that part of the fuel under the distributor is practically not involved in the combustion process. In addition, it is necessary to accurately distribute the air flow, which also leads to a complication of the design of the furnace and more difficult conditions for its maintenance and operation.

A known method of providing fuel combustion in a furnace with a vertically oriented housing, implemented using a solid fuel furnace containing a combustion chamber with a visor in its upper part, which is adjacent to the side and rear walls and divides the combustion chamber into upper and lower parts, a door with a glazed window on the front wall of the combustion chamber for loading fuel, the lower and slit-like upper air supply for blowing the glass of the door window with a flat air stream and forming an afterburning area inside the combustion chamber combustion products and a pipe for the removal of combustion products located in the upper rear of the combustion chamber.

The air for primary combustion of solid fuel is supplied to the combustion chamber both from the side of the rear wall of the furnace and from the side of the lower part of the front wall of the combustion chamber using dampers controlled from the front of the furnace. The afterburning (secondary combustion) of unburned fuel particles is carried out by supplying two air streams to the combustion chamber, one of which (cold) is controlled by a damper, and the second uncontrollable warm one after blowing the glass of the door enters the front of the combustion chamber into the afterburning area of unburned solid fuel products. The walls of the combustion chamber are lined with brickwork and placed inside a metal casing. Between the walls of the combustion chamber and the casing there is a space through which air is drawn from the lower part of the heated room to cool the furnace casing (US patent 4766876 A, F24B 5/02, 08/30/1988 - prototype).

The disadvantage of the prototype is that when changing the composition of solid fuels, high furnace efficiency is not ensured. This is explained by the fact that not all chemical energy of solid fuels (of various compositions) can completely turn into thermal energy without regulating the necessary amount of hot air to burn after burning unburned particles of this type of solid fuel. Fully unburned solid fuel residues, flying out of the furnace pipe, reduce its efficiency and worsen the ecology of the environment. In addition, another disadvantage of the prototype is the brick lining of the walls of the furnace, which reduces its mobility for heating summer and temporary buildings.

The objective of the invention is to remedy these disadvantages and create a method of burning fuel, the use of which will significantly increase the completeness of fuel combustion, heat transfer and increase the operating time of the furnace at a constant fuel consumption.

The solution to this problem is achieved by the fact that in the proposed method of burning fuel in a furnace, mainly a domestic one, containing a housing with a door for loading fuel, in which channels for supplying air to the combustion chamber with a combustion zone, channels for removing products of fuel combustion from the combustion chamber, a chimney for removal of combustion products, which consists in laying fuel in the combustion zone of the furnace with subsequent ignition of the fuel, burning it with heat, obtaining directly the combustion products themselves, followed by selection According to the invention, the main stream of products of combustion is divided into at least two additional intermediate streams by installing a profiled screen with windows in the path of the main stream, mainly in the furnace, by heating the heating elements of the furnace and removing said combustion products through a chimney peripheral zone, and direct the obtained additional intermediate flows through the said windows to the walls of the furnace, after which, preferably, each additional intermediate The primary flow is expanded and passed along the walls of the furnace in its part located in the immediate vicinity of the pipe, then additional intermediate flows are deployed, mainly all, at least once, towards each other and give each flow a rotational movement, mainly in a spiral, then mix additional intermediate rotating streams with each other and direct the resulting main rotating stream into the chimney.

To optimize the mixing conditions of the flows and increase their path, the mixing zone and imparting rotational motion to the flows are separated from the channels for additional intermediate flows.

To optimize the design of the furnace, the profiled screen is installed at a distance equal to 0.1-0.5 of the height of the furnace from the top cover of the furnace.

The lower value of the specified ratio is selected based on the fact that with a further decrease in it, there is a significant deterioration in the operating conditions of the furnace associated with a deterioration in the conditions of swirling flows and, accordingly, the efficiency of the furnace.

The upper value of this ratio is chosen on the basis that, with its further increase, there is a significant deterioration in the overall dimensions of the furnace without a significant improvement in the conditions of heat transfer from the combustion products to the heating elements of the furnace.

The invention is illustrated by drawings, in which Fig. 1 shows a front view of a furnace for implementing this method, Fig. 2 is a longitudinal section of a furnace, Fig. 3 is a top view of a furnace, and Fig. 4 is a perspective view of the distribution of combustion products over the furnace body; .

The furnace for implementing the indicated method 1 comprises a housing 2 with walls 3 and an upper cover 4. In the housing 2, a combustion chamber 5 with a combustion zone is located and channels 6 for supplying air to the combustion zone of the combustion chamber 5 and channels 7 for exhausting combustion products from the combustion chamber 5 are made. The channels 7 are connected to the exhaust pipe 8. On the housing 2 is mounted rotatably in the frame of the door 9 with a lock. In the upper part of the furnace 1, between the combustion chamber 5 and the exhaust pipe 8, a profiled screen 10 is installed with the formation of a cavity 11 bounded by an upper cover 4, walls 3, and a profiled screen 10. In the profiled screen 10 there are made windows 12 in the form of grooves, mainly in its peripheral zone 13, connecting the cavity of the combustion chamber 5 with the cavity 11 using horizontally oriented channels 14. The horizontally oriented channels 14 open into the cavity 11 towards each other, and between the output parts 15 of these channels 14 install flax swirler 16.

In an embodiment, the horizontally oriented channels 14 are formed by lateral elements of the furnace body, mainly by the walls 3 of the furnace 1, and vertically arranged partitions 17 on the profiled screen 10.

The proposed method is implemented as follows.

Fuel is placed in the combustion chamber 5 of the furnace 1 through the door 9 and set on fire. The air is supplied through the air supply channels 6 to the combustion zone of the combustion chamber 5, the exhaust products are removed through the channels 7. When the fuel is burned, heat is generated with the formation of the main stream of combustion products having a high temperature. The resulting main stream of combustion products is divided into at least two additional intermediate streams due to the installation of a profiled screen 10 with windows 12 in its path, mainly in its peripheral zone 13. The resulting additional intermediate streams through the windows 12 are directed to the walls 3 of the furnace 1. Then each additional intermediate stream is deployed and directed along the walls 3 of the furnace 1 in its part located in close proximity to the exhaust pipe 8, after which additional intermediate streams of they are turned at least once towards each other and fed into the cavity 11 through the outlet parts 15 of the channels 14. From the outlet parts 15 of the channels 14, additional intermediate flows are fed to the swirler 16 installed in the cavity 11. Passing through the swirl 16, each additional intermediate flow acquires a rotational movement, mainly in a spiral, which leads to the intensification of heat transfer of these flows between themselves and the heating elements of the furnace. Then additional intermediate rotating streams are mixed with each other and sent to the exhaust pipe 8.

The tests carried out by the author and applicant of a full-sized furnace sample for the implementation of the proposed method showed that the temperature of the exhaust furnace gases decreased by approximately 200-300 ° C with a simultaneous increase in the furnace operating time with constant fuel consumption, which significantly increased the efficiency of the furnace.

The use of the proposed technical solution will make it possible to intensify the heat exchange between the hot furnace gases and the heating elements of the furnace, while ultimately increasing the length of the channel from the combustion chamber to the exhaust pipe, allowing the hot furnace gases to rotate, which will ultimately increase the efficiency of the working process and the efficiency of the furnace .

Claims (4)

1. The method of burning fuel in a furnace, mainly a domestic one, comprising a housing with a door for loading fuel, in which channels for supplying air to the combustion chamber with a combustion zone, channels for removing the products of combustion of fuel from the combustion chamber, a chimney for removing combustion products, are made in laying fuel in the combustion zone of the furnace with subsequent ignition of the fuel, its combustion with the release of heat, obtaining directly the combustion products themselves, followed by taking heat from the combustion products by heating them with a heater elements of the furnace and the removal of the aforementioned combustion products through the chimney, characterized in that the main stream of combustion products is divided into at least two additional intermediate flows by installing a profiled screen with windows in the path of the main stream, mainly in its peripheral zone, and direct the obtained additional intermediate flows through the said windows to the walls of the furnace, after which, preferably, each additional intermediate stream is deployed and passed along the walls of the furnace in its part, located in close proximity to the pipe, then additional intermediate flows are deployed, mainly all at least once, towards each other and give each flow a rotational movement, mainly in a spiral, then the additional intermediate rotating flows are mixed together and direct the resulting main rotating stream into the chimney. 2. The combustion method according to claim 1, characterized in that the zone of mixing and imparting rotational motion to the flows is separated from the channels for passing additional intermediate flows. 3. The method according to claim 1, characterized in that the profiled screen is installed at a distance equal to 0.1-0.5 of the height of the furnace. 4. The method according to claim 1, characterized in that the profiling of the screen is performed in the form of the letter "V" with the location of the formed rib approximately along the axial vertical line of the furnace.

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