RU7470U1 - SOLID FUEL COMBUSTION DEVICE - Google Patents

Abstract

1. A device for burning solid fuel, containing a cylindrical combustion chamber, equipped with a tangentially located nozzle, a gas outlet window and an grate, a fuel hopper, a fuel supply device, a blower fan, characterized in that the combustion chamber is equipped with an outer air jacket and an inner one aligned with it a cylindrical screen mounted on the gas outlet, and the fuel supply device is made in the form of an ejector installed between the nozzle and the fuel hopper, and is connected o through an air jacket with a blower. 2. The device according to claim 1, characterized in that the grate is installed in the lower part of the combustion chamber symmetrically with respect to the vertical axis of the combustion chamber. The device according to claims 1 and 2, characterized in that the fuel supply device comprises an opening hatch made in the wall of the combustion chamber at the level of the grate. 4. The device according to claim 1, characterized in that the air jacket is connected by an adjustable hole to a part of the combustion chamber located below the grate.

Description

C F23B1 / 38

SOLID FUEL COMBUSTION DEVICE

The device is designed to generate thermal energy by burning solid fuel, for example, wood waste, which can be used for water in boilers, air in drying heat generators. $ ОЗС ШФ®Рзх

heating of residential and industrial buildings, etc.

A device for burning solid fuel (naT.N 2037097 RU, ШК® F23B1 / 36, 1992) is known, comprising a combustion chamber, a grate installed in the lower part of the combustion chamber, a fuel hopper, a fuel supply device made in the form of a rotary plunger, blasting a fan connected to the combustion chamber through the lower part of the hopper and the grate.

This device provides efficient combustion of solid fuels. However, a solid fuel supply mechanism, including a gear motor, a rotary plunger with bearings, at high temperatures, dust, ash, and gaseous products of thermal decomposition of fuel getting into it cannot be reliable enough in operation. In addition, the combustion of fuel on the grate is not quite intense due to the access of oxygen to a small area of fuel particles.

A device for burning solid fuel (Pat. Y 2015450 RU, Zh1K R23V1 / 38, 1991), containing a cylindrical combustion chamber equipped with a tangential races j

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the put nozzle, the gas outlet window and the grate, located with an angle of inclination varying from 45 to 12 ° to the horizon, the fuel hopper, the fuel supply device, made in the form of a lowering shaft connecting the hopper to the combustion chamber through the grate, a blower connected to the camera combustion through the nozzle and grate.

This device provides complete combustion of bulk solid fuel. The disadvantages of this device, selected by the authors as a prototype, include the following. Cold air is fed into the combustion chamber through the nozzle, which reduces the specific heat output of the device. To supply heated air, a special heat exchanger is required, which complicates the design. In addition, the supply of fuel from the hopper to the combustion chamber under the action of gravitational forces does not ensure uniformity of its receipt, which leads to an incomplete combustion with excess fuel and necessitates the afterburner. In addition, the combustion of fuel on the grate causes slag formation on it, requires the use of heat-resistant materials, which, in combination with the special shape of the grate, complicates the design of the device.

The problem that was solved when creating a utility model was associated with simplifying the design of the device to reduce the cost of its manufacture and operating costs while maintaining or increasing the thermal power of the device.

equipped with an external air jacket coaxially located with it and an internal cylindrical screen mounted on the gas outlet window, and the fuel supply and fuel device is made in the form of an ejector installed between the nozzle and the fuel hopper and is connected through the air jacket to the blower fan.

In addition, the grate is installed in the lower part of the combustion chamber symmetrically with respect to the vertical axis of the combustion chamber.

In addition, the fuel supply device includes an opening hatch made in the wall of the combustion chamber at the level of the grate.

In addition, the air jacket is connected by an adjustable opening to a part of the combustion chamber located below the grate.

The essence of the solution of the problem is explained as follows.

The implementation of the feed device in the form of an ejector and its location between the fuel hopper and the nozzle allows you to evenly feed small amounts of fuel together with air into the combustion chamber, which have time to burn in suspension in a spiral-wound air flow. The movement of fuel particles along a spiral trajectory is facilitated by the installation of a cylindrical screen on the gas outlet window, which increases the path of fuel in the combustion chamber. This constructive solution allows you to abandon the complex designs of grate grates and their interface with the combustion chamber. In order that the thermal power does not decrease, the combustion chamber is equipped with an air jacket. It simultaneously serves as a thermal insulation of the combustion chamber, eliminating large heat losses, and as a heat exchanger for the outside air entering the combustion chamber. Simplification of the design while maintaining the thermal power of the device is the placement in the lowering zone of large particles of fuel entering through the nozzle, a grate of a simple shape. Unburned fuel particles fall on this grate and burn out on it in a stream of air entering through a metered hole from the air jacket under the grate. These design solutions allow not to use a special afterburner, as in known devices.

Simplification of the shape of the combustion chamber and the indicated location of the grate allows to obtain an additional technical result. It is provided by the execution in the wall of the combustion chamber of an opening hatch located at the level of the grate. This hatch allows you to burn in combination with the main fuel a large-sized fuel, for example, forest waste (croaker, waste, etc.), loaded through the hatch to the grate. Through the hatch, it is also possible to clean the grate and the space under it from ash and slag not carried away by the air stream, or from sand that has fallen into the combustion chamber with fuel.

In the study of novelty, no well-known technical solutions were found that were discouraged by a similar set of distinctive features aimed, together with well-known features, to solve the task, which allows us to conclude that the proposed technical solution meets the criterion of novelty.

The essence of a specific implementation of the device is illustrated by drawings. Figure 1 shows a side view, figure 2 is a top view, i

The device comprises a cylindrical combustion chamber 1 having a bottom 2, a cover 3 with a gas outlet 4 and a cylindrical screen 5. On the outside of the chamber, a shell b of an air jacket 7 is fixed coaxially with it on the bottom 2 and the wing 3; a grate is located in the lower part of the combustion chamber 9. The air jacket has a flange 10 for connecting a blower fan. An opening 11 of an adjustable size is made in the wall of the combustion chamber below the grate. On the side of the combustion chamber is a fuel hopper 12 connected to the nozzle 8 through an ejector 13, which is connected by air ducts 14 and 15 to the air jacket. The duct 15 has a nozzle 16 at the end. The fuel hopper has a neck 17 for receiving fuel from a storage or storage tank. In the side wall of the combustion chamber and the side of the air jacket are made doors 18 of the hatch 19.

The device operates as follows.

The fuel from the hopper 12 is blown by a stream of hot air supplied by the blower fan through the air jacket 7, the air duct 15 and the nozzle 16 into the ejector 13. The draft in the ejector is created due to the high-pressure head of the air stream coming from the air duct 15 and discharges created at the outlet of the ejector with air, supplied to the ejector through the duct 14, and in the combustion chamber by removing hot gases from it. The mixture of fuel and air is supplied from the ejector to the nozzle 8 and is blown into the combustion chamber. Placing the nozzle tangentially to the combustion chamber ensures the formation of a vortex in the combustion zone. This is facilitated by the presence of a cylindrical screen 5 at the gas outlet window, which prevents the creation of a thrust of an air stream in the gas outlet window until the fuel particles fall below the screen. Unburnt large particles of fuel are lowered onto the grate 9, where they burn out in a stream of air coming from the bottom of the air jacket through the hole 11. Gases, which are a mixture of combustion products and flame, enter the heat exchanger connected to this device through the gas outlet window. Depending on the layout of this device and the heat exchanger, it may have a vertical or horizontal or intermediate design. The authors tested the full-scale sample of the device in combination with an air heat exchanger mounted vertically above the gas outlet window. Wood fuel and natural moisture shavings (40-60%) were used as fuel. The maximum thermal power with a combustion chamber diameter of 800 mm was about 1 MW. Fuel consumption - 1.2. The air temperature in the heat exchanger was: at the inlet - 15 ° C, at the outlet - 90 ° C. The device was connected to a drying chamber for drying lumber. Drying time of 12 m of boards from 60% humidity to 12% humidity was 48 hours. The average sawdust consumption was 0.8 m per 1 m of sawn timber. This device is economically feasible to use where there are large amounts of waste wood processing or small solid fuel (coal, peat).

Claims (4)

1. A device for burning solid fuel, containing a cylindrical combustion chamber, equipped with a tangentially located nozzle, a gas outlet window and an grate, a fuel hopper, a fuel supply device, a blower fan, characterized in that the combustion chamber is equipped with an outer air jacket and an inner one aligned with it a cylindrical screen mounted on the gas outlet, and the fuel supply device is made in the form of an ejector installed between the nozzle and the fuel hopper, and is connected o through an air jacket with a blower fan.  2. The device according to claim 1, characterized in that the grate is installed in the lower part of the combustion chamber symmetrically with respect to the vertical axis of the combustion chamber.  3. The device according to claims 1 and 2, characterized in that the fuel supply device comprises an opening hatch made in the wall of the combustion chamber at the level of the grate. 4. The device according to claim 1, characterized in that the air jacket is connected by an adjustable hole to a part of the combustion chamber located below the grate.