RU2417341C2 - Procedure facilitating combustion of fuel - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: procedure facilitating combustion of fuel, mainly, wood, in furnace with vertically directed case whereat channels supply air into combustion zone, consists in stacking fuel in combustion zone of furnace, in successive supply of air and in igniting. Fuel is stacked in the furnace, and an upper part of formed volume of fuel is ignited. Channels supplying air into the combustion zone ensure supply of air into an upper area of the combustion zone. One, main, part of channels is maintained continuously open, while another, additional one is opened as soon, as fuel has been combusted and as zone of combustion travels downward. At initial and successive moments air is supplied into the combustion zone via the main channels, while closer to termination of combustion process air is supplied through main and additional channels.

EFFECT: increased completeness of fuel combustion, of heat emission and increased duration of furnace operation at invariable consumption of fuel.

3 cl, 2 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, garbage (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 are not effective for long-term economic burning 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 patent 4782765, 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 zone - 20-40% (patent EP 005303, application No. 200301136 dated 04/19/01, IPC F24B 1/00, 5/00).

The disadvantage 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 body, 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 is uncontrollable warm, after blowing the glass of the door, it 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 for providing fuel combustion, mainly firewood, in a furnace with a vertically oriented housing, in which the air supply channels to the combustion zone are made, which consists in laying fuel in the combustion zone of the furnace with subsequent air supply and ignition, according to According to the invention, the fuel is placed in a furnace, the upper part of the formed volume of fuel is ignited, the air supply channels to the combustion zone are made in such a way that air is supplied to the upper region of the combustion zone, one, the main, part of the channels is kept constantly open, the other, additional, open as the fuel burns and the combustion zone moves downward, while air is supplied to the combustion zone through the main channels at the initial and subsequent times, and closer to the end of the combustion process through primary and secondary.

To optimize the combustion process, the channels are opened automatically, for example, with fuel, as the fuel burns out below a predetermined height.

To optimize the design of the furnace, the area of the passage section of the additional channels is (0.1 ... 0.75) of the area of the passage section of the main channels.

The lower value of the specified ratio is selected on the basis that with a further decrease in it, there is a sharp deterioration in the combustion conditions of the lower part of the fuel column, associated with a small consumption of air for combustion.

The upper value of the specified ratio is selected based on the fact that with its further increase, the mass-dimensional characteristics of the furnace deteriorate.

The invention is illustrated by drawings, where figure 1 shows a longitudinal section of a furnace used to implement this method, the position of the fuel and the direction of air flow at the initial time, figure 2 is a longitudinal section of the furnace, the position of the fuel and the direction of air flow at the final moment time.

The specified method is implemented as follows.

Through the door 8 in a vertically oriented housing 1 of the furnace, in the combustion zone 2, lay fuel 9, for example firewood. Through the outlet parts 5 of the channels 3, air is supplied to the combustion zone 2. Channels 4 at this time are closed using the device 6. The upper part of the formed column of fuel 9 is set on fire. Fuel 9 begins to burn in its upper part, and the combustion process itself continues for a rather long time, since not all fuel is ignited and burns at once, and its upper part, limited by the walls of combustion zone 2. The combustion products are removed through the pipe 10. As the upper burns out parts of the fuel column 9, if necessary, add new portions of fuel through the door 8, which are then burned. Most of the previously laid fuel column 9 remains in its original state.

When the fuel column 9 burns below a predetermined level, for example, below half the column, the air entering through the channels 3 is not fully involved in the combustion process, which leads to a deterioration in the conditions of mixture formation, and the fuel starts to burn with less efficiency. In this case, using the device 6, open the channels 4, and air is supplied to the combustion zone through their outlet parts 7, which contributes to the continuation of the combustion process with a given efficiency. The combustion products are also discharged through the pipe 10.

To optimize the design of the furnace, the area of the passage section of the additional channels is (0.1 ... 0.75) of the area of the passage section of the main channels.

The tests carried out by the authors and the applicant of a full-sized sample of the proposed furnace, in which this method of providing fuel combustion is implemented, confirmed the correctness of the design and technological solutions.

Using the proposed technical solution will improve the efficiency of the furnace and increase its time with constant fuel consumption.

Claims (3)

1. The method of ensuring the combustion of fuel, mainly wood, in a furnace with a vertically oriented body, in which the air supply channels to the combustion zone are made, which consists in laying fuel in the combustion zone of the furnace with subsequent air supply and ignition, characterized in that the fuel is placed in the furnace , set fire to the upper part of the resulting fuel volume, while the air supply channels to the combustion zone are such that air is supplied to the upper region of the combustion zone, and one main part of the channels is constantly kept open ytymi, other additional open as the combustion and the combustion zone downward movement, the air in the combustion zone in the initial and subsequent times fed through the main channels, and near the end of the combustion process - through the primary and secondary. 2. The method of providing fuel combustion according to claim 1, characterized in that the channels are opened with fuel as the fuel burns out below a predetermined height. 3. The method of providing fuel combustion according to claim 1, characterized in that the additional channels are performed with a passage area of 0.1 ... 0.75 of the passage area of the main channels.

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