RU2423646C1 - Device to burn lump solid and liquid fuels in pulsating flow - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: device to burn lump solid and liquid fuels in a pulsating flow comprises a shaft with two horizontal fire grates, a pipe, a heating surface, a fuel supply tube, a fuel hopper, an ignition device, besides, the heating surface is arranged away from the combustion zone, the fuel supply pipe is located outside the shaft, its free end is connected to a ring-shaped plate installed at the distance of 1.5-2 of the shaft diameter from its lower cut.

EFFECT: invention helps to increase reliability of furnace operation, especially with low consumption rates of liquid fuel.

2 dwg

Description

The invention relates to a furnace technique and can be used for the simultaneous combustion of solid and liquid fuels in various thermal power plants.

A device is known for burning lumpy solid fuel in a pulsating flow, comprising a vertical shaft with two parallel horizontal grate grids and a layer of fuel placed between them and a pipe mounted above the upper grid inside the shaft, the cross section of which is no more than 4 times smaller than the shaft section. The known device is not adapted for the simultaneous combustion of liquid fuel (AC 673809 from 07.15.79, bull. No. 26).

It is also known a device adopted for the prototype (patent No. 688769, additional to the copyright certificate No. 228216, publ. 09/30/79, bull. No. 36), including a vertical cylindrical shaft with a horizontal grate, placed above the grate heating surface, fuel supply pipe in the form of a flat horizontal spiral with holes, hopper, ash pan, ignition electrodes, holes for supplying additional air.

The main disadvantages of this device include the low reliability of the furnace at low liquid fuel consumption due to the frequent coking of the fuel supply pipe located in the high-temperature zone (above the grate). In addition, the presence of holes for supplying additional air located in the mine above the grate, lead to large acoustic losses.

A device for burning lumpy solid and liquid fuels in a pulsating flow, comprising a shaft with a horizontal grate, a pipe, a heating surface, a fuel supply tube, a fuel hopper, an ignition device, characterized in that the heating surface is removed from the combustion zone, the fuel supply tube is located outside the mine moreover, its free end is connected to an annular plate located at a distance of 1.5-2 diameter of the shaft from its lower cut.

The proposed device can improve the reliability of the furnace, especially at low liquid fuel consumption. This is achieved by eliminating the conditions of coke formation of liquid fuel on the inner walls of the heating surface. In the proposed device, the heating surface is removed from the high temperature region and is located in the upper part of the mine, where the gas temperature is lower than the coking temperature of hydrocarbon combustible liquids. Heated liquid fuel is burned with an open flame from the surface in an annular plate located at the bottom of the shaft. The annular shape of the plate prevents the ash residue from entering the liquid fuel. The ash residue is concentrated in a plate. In the proposed device, the combusted liquid fuel is additionally heated by the heat of the ash residue of the burnt solid fuel transmitted through the walls of the plate. The distance from the lower cut of the shaft to the ring-shaped plate, equal to 1.5-2 diameters of the shaft, provides an acoustic "decoupling" of the shaft with the plate and the entry of liquid fuel combustion products into the shaft due to the self-tightening.

To clarify the invention, figure 1 shows a diagram of a device for burning solid and liquid fuels in a pulsating flow.

The device includes:

an annular plate 1, a solid fuel ignition device 2, a solid fuel layer 3, a hopper with a loading device 4, a pipe 5, a heating surface 6, grate 7, a shaft 8, a fuel supply pipe 9.

The device operates as follows. Lump solid fuel from the hopper with the charging device 4 is fed to the lower grate 7 and is ignited by the ignition device 2. The combustion products rise up the pipe 5 and are discharged into the atmosphere. The air supply to the combustion zone of solid fuel is carried out through the lower and upper section of the shaft 8 due to self-traction. At the initial moment, before the ignition of lumpy solid fuel, the required thermal energy in the device is provided by the operation of the ignition device 2. In the device, longitudinal self-oscillations are excited. After ignition of the solid fuel, the ignition device 2 is turned off, and the self-oscillating process is supported by the thermal energy released during the combustion of the solid fuel. Liquid fuel is preheated in the heating surface 6 and fed through the fuel supply pipe 9 to the annular plate 1. In the annular plate 1, the fuel is ignited and continues to burn from the surface with an open flame. The combustion products are mixed with the surrounding air, after which the gas mixture is sent to the shaft 8 with the pipe 5 by self-traction. In the shaft 8, incomplete combustion products burn out in the high temperature zone. The ash residue falls through the grate 7 and falls into the annular plate 1. The ash residue heats the walls of the annular plate and, through it, liquid fuel.

An example of a specific implementation.

The proposed device is used as a fire unit in a heating system, which consists of: an annular plate 1, a shaft 8, a hopper with a loading device 4, a tubular heat exchanger 12, a pipe 5, a tank for liquid fuel 13, a control valve 14, an oil cooler 15, a fuel supply pipe 9, gear 16, gas cylinder 17 (figure 2).

The device operates as follows. Coal from the hopper with the charging device 4 is fed to the grate and ignited by the ignition device. Combustible gas is supplied to the ignition device from the cylinder 17, the flow rate of which is regulated by the reducer 16. After the combustion of coal, the supply of combustible gas from the cylinder is stopped. In the pipe 5, self-oscillations of the gas flow are established, and its walls are heated. The pipe 5 is made integrally with a tubular heat exchanger 12 filled with heat-resistant oil. The oil from the heated wall of the pipe 5 is heated and due to convective heat flow begins to circulate through the system "tubular heat exchanger - oil cooler". As the coal ignites, liquid fuel, for example, used oil, is supplied to the annular plate 1 from the tank 13. When the fluid moves along the heating surface located in the pipe 5, the waste oil is heated. After filling the plate with flammable liquid, the latter is ignited. Gaseous products of combustion containing unburned components are sent to the shaft 8, where they are mixed with ambient air, pass through the grate. In this case, the unburned gas components are burned, and additional heat is released. During the operation of the device, the ratio of solid and liquid fuels is regulated in a wide range. This ensures the efficient combustion of solid and liquid fuels, including liquid combustible waste. The main advantage of the heating system is its autonomy - no sources of electrical energy are required.

Thus, the proposed device allows you to simultaneously burn liquid and solid fuels with high reliability and completeness of combustion.

The claimed technical solution meets the criterion of "novelty" presented to the invention, because the claimed combination of features is not known from the analyzed prior art.

The claimed technical solution meets the criterion of "inventive step" for inventions, because The claimed combination of features and the achieved technical results are due to the fact that the claimed technical solution ensures the creation of a stable self-oscillating process without the influence of additional devices (for example: draft devices), which is evidence of the compliance of the claimed solution with this criterion.

The claimed technical solution meets the criterion of "industrial applicability" to the invention, because The claimed technical solution is implemented in a pilot sample using conventional materials and known technologies.

Claims (1)

A device for burning lumpy solid and liquid fuels in a pulsating flow, comprising a shaft with two horizontal grate grids, a pipe, a heating surface, a fuel supply pipe, a fuel hopper, an ignition device, characterized in that the heating surface is remote from the combustion zone, the fuel supply pipe is located outside the mine moreover, its free end is connected to an annular plate located at a distance of 1.5-2 diameter of the shaft from its lower cut.

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