RU82304U1 - SHAFT FURNACE BURNER FOR Limestone Firing (OPTIONS) - Google Patents

Abstract

1. Beam burner shaft furnace for calcining limestone, containing a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made pipe in the pipe with a gap for the passage of cooling water, the burner is installed at the ends of the beam, having an exit window at the bottom, equipped with a flame arrester installed inside the beam. ! 2. A beam burner of a shaft kiln for calcining limestone, comprising a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made in a pipe in the pipe with a clearance for the passage of cooling water, the burners are installed at the ends of the beam, having an exit window at the bottom, bounded inside the beam by two fire barriers installed in its cross section. ! 3. Beam burner shaft furnace for calcining limestone, containing a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made pipe in the pipe with a gap for the passage of cooling water, the burner is installed at the ends of the beam, having in the upper part an exit window with a fire arrester, made in the form of separate holes, over which a visor is installed with a gap for the exit of the gas-air mixture from the beam.

Description

The utility model relates to industrial power engineering and can be used for gas heating of large-scale calcareous kilns.

Known beam multi-nozzle burner shaft furnace containing a water-cooled casing, located in the casing of air and gas manifolds with nozzles for separate supply of gas and air to the furnace. (Aut. Certificate. USSR, No. 894300, IPC F27B 1/00, 1981)

The disadvantage is the high uneven distribution of combustion products over the mine section, incomplete combustion of fuel due to the lack of preliminary mixing of air and gas, low intensity of heat and mass transfer of combustion products with limestone.

The closest in technical essence is a beam burner of a shaft furnace containing a water-cooled housing with nozzles for supplying and discharging water, in which air and gas collectors with nozzles for separate supply of air and gas to the furnace are located. (Utility Model Patent No. 42098 MPK7 F27B 1/00, 2004).

The disadvantage of this device is the large (up to 10%) losses with unburned fuel, due to incomplete combustion of gas and losses for cooling the beam and the lack of a uniform distribution of combustion products over the cross section of the furnace.

The technical result achieved by the claimed utility model is to increase the efficiency of the use of gaseous fuels, to more evenly distribute the combustion products over the cross section of the furnace to produce higher quality lime, and to increase the overhaul period of the furnace.

The technical result is achieved by the fact that the lined water-cooled beam for supplying gas and air to the furnace, with nozzles for supplying and discharging water, a pipe is made in the pipe with a gap for the passage of cooling water, has burners at the ends and an exit window made in the lower part and provided flame arrester installed inside the beam. The exit window may be limited inside the beam by two fire barriers installed in its cross section. The exit window can be made in the upper part of the beam in the form of separate holes, over which a visor is installed with a gap for the exit of the gas-air mixture from the beam.

Figure 1 shows the proposed beam burner, figure 2, figure 3, - embodiments of the proposed beam burner.

The beam burner of a shaft limestone kiln consists of a lined water-cooled beam 1, a pipe made in a pipe with a gap 2 for the passage of cooling water, and a pipe for supplying water 3 located near its ends, a pipe for draining water 4. At the ends of the lined water-cooled beam 1 there are end gas burners 5. In the lower part, the lined water-cooled beam 1 has

output window 6, for the options in figure 1 and figure 2. For the embodiment of FIG. 1, the exit window 6 is provided with a fire arrester 7 mounted inside the beam. For the embodiment of FIG. 2, the exit window 6 is limited by two flame arrester 7 mounted inside the beam in its cross section. For the variant of figure 3, the exit window 6 for the exit of the gas-air mixture from the beam, is located in its upper part, made in the form of a gap between the beam and the visor 8. The flame arrester 7 is made in the form of separate holes.

Beam burner shaft furnace for calcining limestone works as follows. Fuel gas and air enter the burners 5, installed at the ends of the lined water-cooled beam 1. If necessary, adjust the combustion temperature of the mixture in the burner 5 serves recirculating combustion products. From the burners 5, the mixture enters the lined water-cooled beam 1. Cooling water enters the gap 2 between the beam pipes through the inlet pipe 3, is heated from the outer pipe, gives off heat to the inner pipe and is removed through the outlet pipe 4. This reduces the heat loss of the fuel with cooling water . Further, for the embodiment of FIG. 1, from a lined water-cooled beam, through the outlet window 6 with a flame arrester 7, the combustible mixture enters the furnace volume. High speed, low temperature of the mixture inside the beam 1 and the flame arrester 7 do not allow ignition of the mixture inside the beam 1. The placement of the flame arrester 7 inside the beam 1 in the low-temperature flow of the gas-air mixture ensures its reliable cooling. The flame arrester 7 eliminates the "slip" of the flame into the beam 1. Into the layer

lump of limestone in the furnace comes prepared for combustion gas-air mixture. This eliminates the underburning of fuel in the inter-limestone space.

The effectiveness of the proposed design of the beam burner with respect to heat and mass - exchange processes of the interaction of the flame with limestone can be increased if the burner allows you to create a pulsating flow of gas combustion products. To this end, as shown in Fig. 2, two fire arresters 7 are mounted towards each other, inside the beam 1, in its cross section on both sides of the output window 6. With this embodiment of the structural solution of the beam burner, there are flame pulsations in the output window of the beam, which contribute to equalizing the temperature of the gases in the cross section of the furnace and intensifies heat and mass transfer processes of fuel combustion and calcination of limestone. In the space between the fire arresters 7 and the exit window 6, the speed of the non-flammable gas-air mixture is less than the speed of flame propagation. This provides a "slip" of the flame from the furnace into the space of the beam 1 between the flame arrester 7. But as soon as this happens, the flow rate between the flame arrester 7 inside the beam increases sharply due to an increase in the temperature of the flow inside the beam, becomes higher than the speed of flame propagation, and the combustion of the mixture is transferred into the furnace, outside the exit window 6. Thus, a pulsating stream of combustion products enters the layer of lump limestone in the furnace from the beam 1, which

helps to equalize the temperature of the gases in the cross section of the furnace, intensifies the processes of fuel combustion and calcination of limestone.

For the embodiment of FIG. 3, the burner works in the same way as in the embodiment of FIG. 1, with the difference that the maximum temperature of the torch exiting from the exit window 6 (FIG. 3) is above the beam 1, the heating of which from the flame in this the case is less intense due to its partial screening by a visor 8, cooled by the gas-air mixture leaving the beam. The cooling of the visor occurs due to the gas-air mixture under the visor. Since the proposed beam is made of seamless pipes, it is less likely to be damaged in comparison with welded structures.

Thus, the proposed beam burner of a shaft kiln for calcining limestone provides a more uniform distribution of combustion products over the cross section of the kiln to produce lime of higher quality, more economical use of gaseous fuels and an increase in the overhaul period of the kiln.

Claims (3)

1. Beam burner shaft furnace for calcining limestone, containing a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made pipe in the pipe with a gap for the passage of cooling water, the burner is installed at the ends of the beam, having an exit window at the bottom, equipped with a flame arrester installed inside the beam. 2. A beam burner of a shaft kiln for calcining limestone, comprising a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made in a pipe in the pipe with a clearance for the passage of cooling water, the burners are installed at the ends of the beam, having an exit window at the bottom, bounded inside the beam by two fire barriers installed in its cross section. 3. Beam burner shaft furnace for calcining limestone, containing a water-cooled beam for supplying gas and air to the furnace with nozzles for supplying and discharging water, characterized in that the beam is made pipe in the pipe with a gap for the passage of cooling water, the burner is installed at the ends of the beam, having in the upper part an exit window with a fire arrester made in the form of separate holes, over which a visor is installed with a gap for the exit of the gas-air mixture from the beam.