SU1312075A1 - Method for fuel gasification and gas generator for effecting same - Google Patents

Abstract

The invention relates to the field of chemical engineering and can be used to produce low-calorie gas from solid fuels, which allows for greater gasification efficiency. The primary blowing is carried out through the lance 3 along the axis of the reaction chamber 1 of the gas generator, and the secondary blowing through the tuyeres 4 radially and tangentially to its axis to increase the contact time of the vapor-air blowing with ash-carbon residue and better quality mixing of the fuel. This leads to the creation of a uniformly fluidized bed and the complete reaction of the oxygen of the mixture with the carbon of the ash-carbon residue, 2 sec. f-ly, 1 ill. o (l

Description

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The invention relates to chemical engineering and can be used to produce low-calorie gas from solid fuels of any ash content.

The purpose of the invention is to increase the efficiency of gasification.

The drawing shows a gas generator with the formation of gasification zones: A is the reaction zone, B is the afterburning zone, C is the ash cooling zone, npo is a longitudinal section,

The gas generator contains a reaction chamber 1, a conical blowing device 2 with a tuyere 3 for supplying primary blowing and tuyeres 4 for supplying secondary blowing, nozzle 5 - fuel supply nozzle 6 for steam supply, nozzle 7 for supplying steam / air mixture to secondary blowing and ash pipe 8.

The method is carried out as follows.

The fuel is supplied through the fuel supply pipe 5 and the reaction chamber 1 of the gas generator is filled with 50% of the working volume with the fractional composition of the coal, after which the fuel is heated with hot gas or air to the autoignition temperature. When the fuel temperature reaches 900 C, the vapor-air mixture is supplied. The gasification process begins. For the stationary mode of gasification, the following operations are performed simultaneously; steam air blow through lance 3 primary blow is supplied; EI in the amount of 65-75% of the total blow for gasification, and then steam air blow is fed through secondary tuyeres 4 in the amount of 25-35% of the total blow for gasification The secondary vapor-air blowing is carried out tangentially radially to increase the contact time of the vapor-air blowing with the ash-carbon residue for better quality fuel mixing and to reduce the linear velocities along the axis of the gas generator. All this is necessary to create a uniformly fluidized bed in the afterburning zone in order to create conditions for the oxygen to fully react with the carbon of the sol-carbon residue, as well as to minimize the ash of the carbon-ash residue in the reaction zone A.

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ABOUT

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The gasification of boiling solid fuel is carried out at 900-1050 s, with the coefficient of excess air in the reaction zone being 0.4-0.5. To maintain the temperature in the gas generator within the prescribed limits, steam is added to the air in an amount of 25-35% depending on the properties of the coal and the design of the gas generator.

During coal gasification, porous particles are formed, the density of which is less than the density of the original coal.

To remove the ashes, it is necessary that the ash particles agglomerate and their porosity decreases. In the particles of ash remains. Carbon, which with the coefficients of excess air

0.4-0.5 cannot be used. 0 I

To agglomerate the ash, remove from

her carbon creates the afterburning zone B. Into the afterburning zone, a vapor-air mixture of the same composition is supplied as

5 on the primary blast. Its mass flow rate is 25-35% of the total gasification flow. Ash particles that fall into the afterburning zone B contain carbon 30-50% - from the original

Q is the carbon content of the fuel, and since zone B receives 25-35% of the total mass flow rate of vapor-air blowing, the excess air ratio in this zone is 0.7-1.0. This raises the temperature of the ash until softened, carbon is removed and agglomeration of collisional particles occurs. The porosity of the agglomerated particles will decrease, and the specific weight will increase due to the formation of a monolithic particle. The force of the frontal pressure on the particle becomes less than the force of its gravity, the decarbon-degraded particle falls and, falling into

The ash cooling zone B is cooled by the incoming steam. A portion of the heat energy is transferred to the steam, which later participates in the gasification process. The agglomerated ash particles are removed from the gas generator through the ash removal pipe 8 continuously. Fresh solid fuel is continuously supplied during gasification through the fuel supply pipe 5, depending on the performance of the gas generator. For a given performance of the gas generator, the fluidized bed level is maintained constant due to the constant fuel supply.

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for example, a predetermined speed of rotation of the feed screw through the pipe 5, and accordingly a certain steam-air mixture feed by adjusting the steam-air steam supply blow through the tuyere 3 to the pipes 6 and 7.

Claims (1)

1. A method of gasification of a fuel in a fluidized bed, including the supply of a vapor-air mixture for primary and secondary blowing, characterized in that, in order to increase the efficiency of gasification, an vapor-air mixture for primary blowing is supplied along the axis of the gas generator, for the secondary - radially and tangentially axis , while the flow rate of the primary vapor-air mixture is 65-75% of the total consumption for gasification. 2, A gas generator containing a reaction chamber and a conical blowing device with tuyeres for supplying a blow, characterized in that the tuyere for the primary blowing is located along the axis of the gas generator, and the tuyeres for the secondary blowing are arranged radially and tangentially in height by means of a cone of the blowing device, the ratio of the internal diameter of the tuyere for the primary blowing to the internal diameter of the gas generator is 0, t-0.2.