SU1665181A1 - Method for burning powder fuel in vertical furnace with liquid slag removal - Google Patents

Abstract

The invention relates to the furnace technology of boilers, can be used in thermal power plants and allows to reduce the concentrations of ash and nitrogen oxides in the combustion products. This is achieved by the fact that the dust-air flows through the burners 2 and 3 are introduced respectively along the floor 10 and the walls 9 of the combustion chamber 1, where they generate a large amount of heat, which is partially absorbed by the working medium flowing in the pipes of the screens 8, arranged as along the hearth 10, and along the walls 9. The resulting combustion gases are burned out by secondary portions of air introduced into the axial zone of chamber 1, after which they are discharged through window 7 and then the chimney into the atmosphere. The fuel consumption in the flows introduced along the walls 9 of the chamber is equal to B _c = (0.35 ... 0:43) B, and the consumption of air introduced with fuel along the hearth is 10 (V _p ) and along the walls 9 (V _c ) , are equal respectively V _p = (0.4 ... 0.45) V and V _c = (0.35 ... 0.4) V, where B and V are respectively the total consumption of fuel and air supplied to the combustion . 3 il.

Description

The invention relates to the combustion equipment of boilers and can be used in thermal power plants.

The purpose of the invention is to reduce the concentration of ash and nitrogen oxides in the combustion products.

In FIG. 1 shows a variant of the device for implementing this method, a longitudinal section; in FIG. 2 is a section AA in FIG. 1; in FIG. 3 is a section BB in FIG. 1.

The device comprises a combustion chamber 1, a burner 2 for filling the flames of the near-water space, a burner 3 for filling the torch with spaces near the walls, air nozzles 4, a tap hole 5 for removing slag 6, a window 7 for removing combustion products, screens 8, walls 9 and under 10. Air flows are introduced into the axial region 11 of the combustion chamber 1. Burners 2 and 3 form dust torches 12, filling the near-wall and near-wall space of the combustion chamber 1, and with air nozzles 4, an air stream 13 filling the axial region of the combustion chamber 1. ·

The method of burning pulverized fuel is as follows.

Dusty air flows through burners 2 and 3 are introduced respectively along the hearth 10 and walls 9 of the combustion chamber 1. Once in the combustion chamber 1, the fuel-air mixture flows ignite and emit a large amount of heat, which is partially absorbed by the working medium flowing in the tubes of the screens 8 located both along the hearth 10 and along the walls 9. The resulting gaseous products of combustion are burned out by secondary portions of air introduced into the axial zone 11 of the combustion chamber, and then discharged through a window 7 connected to the boiler flues with heating surfaces' (not shown), and then through the chimney to the atmosphere. The ash contained in the fuel particles melts under the influence of high temperatures, turning into liquid slag, which for the most part sticks to the walls 9 and flows down along the hearth 10. The slag melt 6 is removed through a notch 5. Some ash and slag particles that have not passed into melt 6 and do not flow down in letka 5, together with the combustion products, including nitrogen oxides, is removed into the atmosphere. Maintaining the ratio of air and fuel consumption V _n / V = (0.4-0.45), V _c / V = (0.35-0.4), Vs / V = (0.35-0.45) , achieve minimum concentrations of harmful sampling of fly ash and nitrogen oxides into the atmosphere.

The positive effect associated with the improvement of environmental indicators of combustion is accompanied by the intensification of heat transfer in the furnace, which leads to a decrease in the temperature of the combustion products behind the furnace and boiler, a decrease in heat loss with flue gases discharged into the atmosphere, and an increase in boiler efficiency.

Claims (1)

Claim A method of burning pulverized fuel in a vertical furnace with liquid slag removal by introducing dust and air flows along the walls and the hearth, and secondary air into the axial region of the furnace, characterized in that, in order to reduce the concentration of ash and nitrogen oxides in the combustion products, the fuel consumption in the streams introduced along the walls of the furnace, is equal to B _s = (0.35-0.45) V, kg / s, and the flow rates of air introduced with the fuel along the hearth V _n and along the walls Vc are equal to V _n = (0.40, respectively -0.45) V, m ³ / s; Vc = (0.35-0.40) V, where B and V are, respectively, the total consumption of fuel and air supplied to combustion. 5-5 Dust Fig.Z