SU1027472A1 - Boiler fire-box - Google Patents

Abstract

BOILER FIRING, containing a prismatic shielded combustion chamber with burners located on the front wall and exit window and flat screens located between them, characterized in that, in order to improve efficiency by reducing underburning when burning coarse fuel, the screens are installed perpendicular to the side walls chambers, combustion, at an acute angle to the axis of the burners and with overlapping adjacent screens in the horizontal plane.

Description

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ka The invention relates to devices for burning fuel and can be used in thermal power plants. The boiler furnaces are known, containing shafted screened combustion chambers, with burners located on the front wall and an exit window and flat flares located in the combustion chamber or against the burners. The disadvantages of these furnaces are low profitability due to underburning. This is due to the result of the removal of fine fuel from the combustion chamber, and the separation of coarse fuel into the lower part of the chamber. The boiler furnace is also known; it contains a prismatic screened combustion chamber with burners located on the front wall and an exit window and flat screens 2J located between them. . The aim of the invention is to improve the economy by reducing underburning when burning coarse sand. persistent fuel. This goal is achieved by the fact that in a boiler furnace containing a prismatic screened combustion chamber with burners located on the front wall and an exit window and flat screens located between them, the latter are set perpendicular to the side walls of the combustion chamber at an acute angle to the axis of the burners and with overlapping adjacent screens in the horizontal plane. FIG. 1 shows a furnace with an upper position of the exit window; a longitudinal section (variant 1); FIG. 2 - the same (variant 2}; Fig. 3 - boiler furnace with a lower position of the exit window, longitudinal section; Fig. 4 - section A-A in Fig. 1. The boiler furnace contains a prismatic screened combustion chamber 1 with burners 2 placed on the front wall 3 and the exit window 4. In the combustion chamber 1 there are burners 2 and the exit window 4 there are flat screens 5, installed perpendicular to the side walls 6, at an acute angle about the axes of the burners 2 and with overlapping adjacent horizontal screen 5. At the mouth of a hopper from the funnel 7 can be installed secondary blowing nozzles 8. The furnace operates as follows. Coarse fuel of a wide fractional composition, for example, containing 1.05 ° -20%, R, oooo 2%, 0.5%, is fed into the combustion chamber 1. through the burners, where it ignites, forming A torch that goes along the back wall to iimpma 5. The 5 torch, which consists of a mixture of flue gases and unburned fuel fractions, reaches the screens and turns along them at an angle of 90 + oh and after a second turn at an angle of A.ieo at the leading edges the screen 5 is guided through the gaps between them towards the output window 4. Pr the first spread flow of flue gases at the most 5 screens large fraction of 8 fuel 1000 microns by gravity forces of inertia are discarded in this stream while continuing to burn out therein. Moreover, repeatedly and consistently hit the screen on the screen 5 ,. large fractions of fuel move along the trajectory from the rear wall 3 to the front or to the burners 2 (Figures 1 and 2), or to the secondary blowing nozzle 8 (Fig. 3), i.e. in the zone with a high content of oxygen and with an adequate temperature, which contributes to their complete burnout. The average fraction of fuel size O 1000 - 600 microns after hitting the screen 5; due to the low inertia, they cannot return to the flow of flue gases and therefore fall into the vortex circulation zones formed during the flow around the curtain 5. In these vortex zones h; the middle fractions of fuel burn to the size at which they, through the gaps between shirmalsh 5, enter the space between exit window 4 and screen 5. At the second turn of the flow of flue gases at the front edges of the screen 5 at an angle of 90 + o, the middle fractions failed to burn out by this moment fuels from the negro are separated for the second time into the okolorelelochny region with a high oxygen content or into vortex zones, under the screen 5.s. Installation in the active combustion zone with a cross in the horizontal plane, perpendicular to the side walls m 6 screens 5, made in the form of louvers, inclined at an acute angle to the axes of the burners 2, made it possible to completely block the combustion chamber 1 with the screens 5 along the direction of the continuous torch while ensuring an optimal cross section for the passage of the flue gases to the window 4 and with repeated turning flow of flue gases at an angle greater than 90. This provided almost a full return of unburned fractions of fuel for afterburning to oxygen-rich torch zones. Reducing the loss of fuel from its mechanical loss associated with the entrainment of fuel gaeels increased the combustion efficiency of coarsely dispersed fuel.

The angle of inclination of the screens 5 to the axis of the burners 2 enhances the separation of unburned large and medium fractions of fuel into a torch and prevents the fuel from depositing on these surfaces.

In addition, in this furnace, multistage combustion of fuel is achieved, which makes it possible to lower the temperature level in the combustion chamber 1, leads to a decrease in the formation of nitrogen oxides and increases the reliability of the furnace.

The economic efficiency of the invention lies in the use of fuel coarse grinding, in the absence of a dust preparation system, in reducing the size of the boiler.

G77 / 7 / 7U777 / 7 ///// 7/7 /// 7 77 / /// UL

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Claims (1)

A BOILER BOILER containing a prismatic shielded combustion chamber with burners located on the front wall and an outlet. the window and flat screens located between them, characterized in that, in order to increase efficiency by reducing underburning when burning coarse fuel, the screens are installed perpendicular to the side walls of the combustion chamber, at an acute angle to the axes of the burners and with overlapping adjacent screens in the horizontal plane. yu m fie · "