Downdraft gasification coal-fired boiler

Abstract

The invention relates to a downdraft gasification coal-fired boiler which comprises a boiler body, a base, a grate arranged at the lower end of the boiler body, a smoke exhaust pipe arranged on the top of the boiler body, a vertical clapboard that is arranged at the lower part of the boiler body and divides the boiler body into a gasification chamber and a combustion chamber, a coal throwing gate positioned in front of the gasification chamber and an ash door that is arranged on the base under a fixing grate. The gasification coal-fired boiler is characterized in that the vertical clapboard is arranged on the inner wall of the boiler body, and the lower end of the vertical clapboard is positioned above the grate; the grate is a combined grate and comprises the inclined fixing grate positioned under the gasification chamber and a horizontal moving grate positioned under the combustion chamber; a slag pin hole is positioned on the boiler body above the fixing grate, is inclined and has the angle of inclination being consistent with that of the fixing grate 7. The invention has the advantages of needing not to stop the boiler when in coal throwing or slag removing, no secondary ignition, convenient operation, stable combustion condition, good discharge effect, coal conservation and no special requirement for coal quality.

Description

technical field [0001] The invention relates to a coal-fired boiler, in particular to a downdraft coal-fired gasification boiler. Background technique [0002] The small coal-fired boilers that are common in the market today mainly include ordinary hand-fired boilers, hand-fired boilers with secondary air burnout technology, reverse-fired semi-gas boilers, and positive pressure coal-fired gasification boilers. The gasification boiler is the most advanced and can meet the requirements of the current environmental standards. It is the application of coal-to-gas technology in boiler combustion. [0003] The so-called positive pressure refers to the method of blasting at the bottom of the furnace, using air or water vapor as a gasification agent, and pyrolyzing coal to generate combustible gas. However, the positive pressure coal-fired gasification boilers currently used generally have the following problems: [0004] 1. When the boiler is running, the furnace door cannot be o...

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Problems solved by technology

When the coal quality is improper or the gas purity is not enough, there will be misfires, and the boiler operation is inconvenient

[0006] 3. Low material layer operation, coal drying, dry distillation and gasification are all carried out in a very thin material layer (600mm-1000mm). High-temperature radiation of 500°C-700°C can easily cause thermal explosion of coal and produce coal powder, which is discharged with flue gas, making the emission effect unstable

[0007] 4. It is necessary to open the lower furnace door of the gasification chamber to remove slag. Since the boundary between the slag layer and the oxide layer is not very clear, semi-coke and coal are pressed on the slag layer, so there will be raw coal and ungas when the lower furnace door is opened. The completely liquefied coke is discharged with the slag, resulting in waste of coal burning

[0008] 5. When the furnace type is slightly larger, there is a dead angle for manual slag removal. Moreover, the temperature is higher after the furnace door is opened, and manual slag removal is more difficult. The requirements for coal quality are higher, and the larger slag blocks will be difficult to remove.

[0009] 6. Complicated operation

[0011] 2) When the boiler is running, it is necessary to observe the flame situation frequently to adjust the primary and secondary air. When the gas output or purity is unstable, there will be fire failure or black smoke

[0012] 7. Coal is fed into the gasification chamber at one time, and the air is blown continuously, and coal cannot be added. The gas output and purity have a weak-strong-weak process, so the combustion condition of the boiler is unstable

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