Coal-saving and efficiency-improving type kiln tail coal injection device

Abstract

The utility model discloses a coal-saving and efficiency-improving type kiln tail coal injection device which comprises coal injection pipes arranged on the upper side and the lower side of a tertiary air pipe of a decomposing furnace in the horizontal direction, the ventilation area of each coal injection pipe is not smaller than half of the area of a main coal conveying pipeline, and a spray head is welded to the end, located in the decomposing furnace, of each coal injection pipe. The utility model relates to the technical field of coal saving of a burner of a decomposing furnace, the nozzle assembly at the tail part of the coal injection pipe extends to the center of the decomposing furnace, and pulverized coal is dispersed from the nozzle at 360 degrees without dead angles and is injected into the decomposing furnace, so that the burn-off rate of the pulverized coal is improved, and the after-combustion phenomenon of the pulverized coal is avoided; meanwhile, the two coal injection ducts are arranged up and down to form an oxygen-deficient combustion area and an oxygen-enriched combustion area, so that the generation of oxynitride is reduced and the consumption of ammonia water is also reduced by virtue of the reduction characteristic of carbon monoxide.

Description

Technical Field

[0001] The utility model relates to the technical field of coal saving of preheater decomposition furnace burners in cement manufacturing industry, in particular to a coal saving and efficiency improving type kiln tail coal injection device. Background Art

[0002] At present, most of the new dry process cement production lines with a daily output of 5,000 tons of clinker are designed by Nanjing Cement Industry Design Institute or Tianjin Cement Industry Design Institute Co., Ltd. The coal injection device of the preheater decomposition furnace is a double-channel coal injection pipe for decomposition furnace, with a coal burning capacity of 21-25t / h (total coal supply of four pipes). The coal injection pipe has a simple structure and is easy to maintain, but it is insufficient in process layout and use effect. In the process layout, the four coal injection pipes are placed horizontally on the upper part of the tertiary air duct, which does not achieve the effect of graded combustion. The concentration of nitrogen oxides produced is very high, which increases the cost of denitrification; the other four burners are all facing the center to spray coal powder, and are close to the outlet spreading plate of the raw material entering the decomposition furnace. The mixing degree of coal powder and materials is greatly affected, and the dispersion of coal powder is not enough, which directly causes incomplete combustion of coal powder and increased coal consumption. In view of this, in-depth research on the above problems has led to the creation of this case. Utility Model Content

[0003] In view of the deficiencies of the prior art, the utility model provides a coal-saving and efficiency-enhancing kiln tail coal injection device, which solves the problems raised in the background technology.

[0004] To achieve the above objectives, the utility model is implemented through the following technical solutions: a coal-saving and efficiency-improving kiln tail coal injection device, comprising coal injection pipes arranged horizontally on the upper and lower sides of the tertiary air duct of the decomposition furnace, the ventilation area of ​​a single coal injection pipe is not less than half the area of ​​the main coal delivery pipeline, a nozzle is welded to one end of the coal injection pipe located in the decomposition furnace, the center of the nozzle and the center of the decomposition furnace are located on the same axis, the side wall of the nozzle is staggered with double-layer coal injection holes, nozzles are welded at the position of the coal injection holes, and the sum of the total inner diameter areas of the nozzles should not be less than the inner diameter area of ​​the nozzle.

[0005] The coal injection pipe is welded from 16 mm 316 stainless steel plates or pipes, and the inner diameter of the coal injection pipe is 220-250 mm.

[0006] The above-mentioned nozzle is a 316 stainless steel pipe with a diameter of 200*10mm, the coal injection holes are evenly arranged along the circular array, and the nozzle is a 316 stainless steel pipe with a diameter of 40*10mm.

[0007] The above-mentioned coal injection pipes are arranged up and down, and the distance between the upper coal injection pipe and the lower coal injection pipe is 5-6 meters.

[0008] The above-mentioned coal injection pipes are arranged up and down, the nozzle of the lower coal injection pipe is installed 500mm above the smoke chamber contraction, and the upper coal injection pipe is installed above the tertiary air inlet and the nozzle position of the upper coal injection pipe is not lower than the center line of the tertiary air duct.

[0009] A valve and an electric actuator are installed at one end of the coal injection pipe.

[0010] The utility model provides a coal-saving and efficiency-enhancing kiln tail coal injection device. It has the following beneficial effects: the coal-saving and efficiency-enhancing kiln tail coal injection device has a nozzle assembly at the tail of the coal injection pipe extending to the center of the decomposition furnace, and the coal powder is sprayed into the decomposition furnace from the nozzle at 360 degrees without dead angles, so that the burnout rate of the coal powder is improved, and the afterburning phenomenon of the coal powder is avoided. At the same time, the two coal injection pipes are arranged up and down to form an oxygen-poor combustion zone and an oxygen-rich combustion zone. Relying on its carbon monoxide reduction characteristics, the generation of nitrogen oxides is reduced, and the consumption of ammonia water is also reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the main structure of the coal-saving and efficiency-improving kiln tail coal injection device described in the utility model.

[0012] Figure 2 This is a schematic diagram of the main structure of the coal injection pipe of the utility model.

[0013] Figure 3 For this utility model Figure 2 Schematic diagram of the structure viewed from above.

[0014] In the figure: 1. decomposition furnace; 2. tertiary air duct; 3. coal injection pipe; 4. nozzle; 5. nozzle; 6. smoke chamber; 7. valve. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] Embodiment: In conjunction with the specification Figure 1-3It can be seen that the present application specifically designs a coal-saving and efficiency-enhancing kiln tail coal injection device, including coal injection pipes 3 arranged horizontally on the upper and lower sides of the tertiary air duct 2 of the decomposition furnace 1, the connection part of the coal injection pipe 3 and the decomposition furnace 1 is constructed of high-strength explosion-proof mullite casting material, and an expansion joint is set at the contact position, the ventilation area of ​​a single coal injection pipe 3 is not less than half of the area of ​​the main coal delivery pipeline, and a nozzle 4 is welded at one end of the coal injection pipe 3 located in the decomposition furnace 1, the center of the nozzle 4 and the center of the decomposition furnace 1 are located on the same axis, and the side wall of the nozzle 4 is staggered with Double-layer coal injection holes, with nozzles 5 welded at the positions of the coal injection holes, the sum of the total inner diameter areas of the nozzles 5 should not be less than the inner diameter area of ​​the nozzle head 4, the nozzle 5 assembly at the tail end of the coal injection pipe 3 extends to the center of the decomposition furnace 1, and the coal powder is sprayed into the decomposition furnace 1 from the nozzle 5 at 360° without dead angles, the burnout rate of the coal powder is improved, and the afterburning of the coal powder is avoided. At the same time, the two coal injection pipes 3 are arranged up and down to form an oxygen-poor combustion zone and an oxygen-rich combustion zone. Relying on its carbon monoxide reduction characteristics, the production of nitrogen oxides is reduced, and the consumption of ammonia water is also reduced.

[0017] In the specific implementation process, as a preferred setting, the coal injection pipe 3 is welded with 16mm 316 stainless steel plate or pipe, and the inner diameter of the coal injection pipe 3 is 220-250mm; the nozzle 4 is a 316 stainless steel pipe with a diameter of 200*10mm, and the coal injection holes are evenly arranged along the circular array, and the nozzle 5 is a 316 stainless steel pipe with a diameter of 40*10mm.

[0018] In the specific implementation process, the coal injection pipe 3 is arranged up and down, the nozzle 4 of the lower coal injection pipe 3 is installed 500mm above the constriction of the smoke chamber 6, the upper coal injection pipe 3 is installed above the tertiary air inlet and the nozzle 4 of the upper coal injection pipe 3 is not lower than the center line of the tertiary air duct 2, and the coal powder is sprayed into the decomposition furnace 1 from the nozzle 5 at 360° without dead angle. Two coal injection pipes 3 are used, arranged in the upper and lower layers, the lower one is installed above the constriction of the smoke chamber 6, and the upper one is installed on the upper part of the tertiary air inlet, and the two layers are about 5-6 meters apart. After being sprayed out from the 360° coal injection pipe 3, the coal powder is evenly dispersed, the burnout rate of the coal powder is improved, the afterburning phenomenon of the coal powder is avoided, and the ammonia consumption is also reduced.

[0019] In the specific implementation process, a valve 7 and an electric actuator are installed at one end of the coal injection pipe 3. Through the electric actuator, the coal distribution ratio of the upper and lower coal injection pipes 3 is adjusted at any time according to the combustion effect to achieve the most ideal combustion state.

[0020] In summary, the center of the nozzle 4 of the coal injection device coincides with the center of the decomposition furnace 1, and the coal powder is sprayed into the decomposition furnace 1 from the nozzle 5 in a 360° spread without dead angle. The coal powder is evenly spread after being sprayed out, and the combustion is more concentrated. The burnout rate of the coal powder is improved, and the afterburning of the coal powder is avoided; the two coal injection pipes 3 are arranged up and down, and an oxygen-poor combustion area is formed in the middle position, and a carbon monoxide reduction area is formed above the upper coal injection pipe 3, which reduces the nitrogen oxides generated in the rotary kiln, reduces the concentration of nitrogen oxides, reduces the amount of ammonia water injected, and saves the denitrification cost.

[0021] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coal-saving and efficiency-enhancing kiln tail coal injection device, characterized in that: It includes coal injection pipes arranged horizontally on the upper and lower sides of the tertiary air duct of the decomposition furnace, the ventilation area of ​​a single coal injection pipe is not less than half the area of ​​the main coal delivery pipeline, a nozzle is welded to one end of the coal injection pipe located in the decomposition furnace, the center of the nozzle and the center of the decomposition furnace are located on the same axis, double-layer coal injection holes are staggered on the side wall of the nozzle, nozzles are welded at the positions of the coal injection holes, and the sum of the total inner diameter areas of the nozzles should not be less than the inner diameter area of ​​the nozzle.

2. The coal-saving and efficiency-enhancing kiln tail coal injection device according to claim 1 is characterized in that: The coal injection pipe is welded with 16mm 316 stainless steel plates or pipes, and the inner diameter of the coal injection pipe is 220-250mm.

3. The coal-saving and efficiency-enhancing kiln tail coal injection device according to claim 1 is characterized in that: The spray head is a 316 stainless steel pipe with a diameter of 200*10 mm, the coal spray holes are evenly arranged along a circular array, and the nozzle is a 316 stainless steel pipe with a diameter of 40*10 mm.

4. The coal-saving and efficiency-enhancing kiln tail coal injection device according to claim 1 is characterized in that: The coal injection pipes are arranged up and down, and the distance between the upper coal injection pipe and the lower coal injection pipe is 5-6 meters.

5. The coal-saving and efficiency-enhancing kiln tail coal injection device according to claim 1 is characterized in that: The coal injection pipes are arranged up and down, the nozzle of the lower coal injection pipe is installed 500mm above the smoke chamber shrinkage, and the upper coal injection pipe is installed above the tertiary air inlet and the nozzle position of the upper coal injection pipe is not lower than the center line of the tertiary air duct.

6. The coal-saving and efficiency-enhancing kiln tail coal injection device according to claim 1 is characterized in that: A valve and an electric actuator are installed at one end of the coal injection pipe.

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