SU1451456A1 - Method of burning up fuel in fluidized bed - Google Patents

Abstract

The invention relates to energy and can be used for burning sour solid fuel in boiler furnaces. The invention allows to increase the efficiency of the boilers. Solid fuels are fluidized with an oxidizing stream. The prepared suspension, for example liquid waste, scrubber water or technical water mixed with oils, solid particles with added sulfur-trapping additives, is fed to the upper part of the fluidized bed. The concentration of additives in the suspension is 10-30% by weight. 1 il.

Description

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The invention is energy related and can be used for burning high-sulfur solid fuel in boiler furnaces.

The aim of the invention is to improve the economy.

The drawing shows a diagram of the device, using which the proposed method can be implemented.

The device comprises a fuel supply unit I and a combustion chamber 2 with a gas distribution grid 3, an overflow unit 4 for removing excess ash and light particles of the bed material, a discharge pipe 5 for continuously unloading large or heavy particles. In order to feed the suspension into the fluidized bed 6, an assembly is installed, including an inclined pipe 7, an automatic dispenser 8, a container 9 and a line 10 for supplying the suspension. For supplying approx. 1, the sub grate and in the discharge pipe are fans (not shown).

During operation of the device, solid fuel is fed through node I into chamber 2. An oxidizer is supplied through the gas distribution grid 3 from the bottom of the apparatus - air (during ignition, the products of combustion from the mobile heat generator are flushed through the grid), while the ash is discharged through overflow 4, the dip is removed through the discharge pipe 5, and the products of combustion are fed to the heat using device (boiler, dryer, etc.). To prevent the discharge of coal particles from the fluidized bed 6, an increased amount of air is supplied to the discharge pipe. The prepared suspension, for example, liquid flotation waste, scrubber water or technical water mixed with oils, solid parts г г сер сер сер сер сер сер сер сер сер, is fed into the fluidized bed through an inclined pipe 7, the amount of which is controlled by an automatic metering device 8 by a signal from a temperature sensor (not shown) ). The suspension is supplied from the tank 10 to the zone of the fluidized bed adjacent to its upper boundary. The concentration of additives in the suspension is 10-30 wt.%, Determined by the initial sulfur content of the combustible fuel and viscosity.

The slurry stream enters the fluidized bed, is crushed by particles and. by the flow of gases to large droplets, from the surface of which the liquid phase evaporates, stabilize the temperature of the layer, the droplet volume decreases, and extremely dense packing of particles is formed in it. The outer surface of the droplet is heated and a granule is formed from small particles.

In parallel with the start of the granule formation process, the liquid evaporates from its internal parts, which forms the porosity of the dry granule that is favorable for absorbing sulfur oxides. Thanks

Contact R boils a layer of dry granules with a stream of watered slurry and drops of dry granules that contain unreacted calcium oxide, undergo a hydration reaction — wetted with water, which allows them to absorb additional sulfur dioxide. This is due to the fact that the porosity and pore diameter of the sorbent increase with each subsequent hydration cycle due to the fact that the molar

10 the volume formed with Ca (OH) 2 is approximately twice the molar volume of calcium oxide. An increase in porosity increases the gas permeability of the granule and continues the reaction with the formation of calcium sulfate in its inner layers. This allows the degree of utilization of the calcium additive to be increased to a maximum value.

Example. In the combustion device, which provides an adjustable height of the fluidized bed, adjustable fuel consumption, continuous unloading of light particles from the top through the overflow, and heavy particles from the bottom through the discharge pipe, burn the mixture of industrial products and the enrichment rock of the TsOF “Chumkovskoy PO” Donetsk coal preparation - class 0 - 13 mm kcal / kg; A., 73%; . After the fluidized bed is fired, when the temperature of the layer reaches 950–980 ° C, an aqueous suspension of limestone is supplied to the surface of the layer with a concentration of 23.3 wt.% At a flow rate of 1050 through a metal tube. The steady-state fuel consumption was 3810, the average air velocity over the 2-column gas distribution grid was 2.1 m / s, and the height of the fluidized bed was 1.05 m.

The granules obtained in the fluidized bed, G, had a density of less than 1300 kg / m. The unloading of the granules was carried out through an overflow, the outlet of which was located on the upper boundary of the layer. The excess air ratio was 1.18.

The size class of the obtained granules is 0.5–13 mm, of which 93.2 wt.% Were granules with a size of 1–: 10 mm. The degree of sulfation of the additive was 60%.

The method of fuel bed combustion makes it possible to increase the economics of the process by increasing the degree of use of additives as sulfur dioxide sorbents and reducing harmful emissions into the atmosphere, increasing the specific productivity of the fluidized bed due to effective cooling of the layer and operation of the layer at low values of the excess factor. air spill, the possibility of using finely ground limestone, liquid floattails, etc. — waste from various industries.

Claims (1)

Claims of Invention A method of burning fuel in boiling water by supplying fuel, its fluidization by an oxidant stream and entering into a goal of increasing economic efficiency, is preliminarily supplied with additives of suspension at a concentration of 10-30 wt.%, And for example , „„ „/ D. -lh, | 7СД1ЭП / П I (ИИС. / П, And Hdlll Well burning water, characterized in that, then with a layer of fuel in, a jet in order to increase efficiency, additives are pre-fed into the water with the formation of a suspension at an additive concentration of 10-30 wt.%, and directed / d -lh, | 7СД1ЭП / П I (ИИС. / П, And Hdlll then on a layer of fuel in the form of a jet X /and