Method for rapid ignition and air blast of coal powder double-chamber kiln

Abstract

The application discloses a kind of coal powder double-chamber kiln quick fire hooking and air blowing method, comprising: before the fuel input of No.1 kiln chamber, the coal powder input of No.2 kiln chamber is increased, and the coal powder input of No.1 kiln chamber is maintained unchanged;No.1 kiln chamber is used as combustion chamber, and the kiln is stopped before entering the reversing time;Start the discharge platform to discharge, and implement heat preservation for No.2 kiln chamber;Replace the spray gun;Fill No.1 kiln chamber with stone, adjust the coal powder input to the initial set value, open the kiln, and store heat for the stone in No.1 kiln chamber;When No.1 kiln chamber enters the combustion period, adjust the coal powder input to 30%-50% of the normal value, and send coal powder fuel into No.1 kiln chamber;Repeat the above steps until the spray gun thermocouple temperature of the kiln chamber reaches 600℃, and then restore the fuel input of No.1 kiln chamber;After the quality of the products in both kiln chambers is normal, implement the same operation for No.2 kiln chamber to replace the spray gun.The application can solve the problem of long replacement period of the spray gun in the existing double-chamber kiln, and reduce the waste of resources.

Description

Technical Field

[0001] This invention relates to the field of steel manufacturing and equipment technology, and in particular to a method for rapid ignition and re-airing operation of a pulverized coal double-chamber kiln. Background Technology

[0002] A typical double-chamber kiln consists of two kilns (kiln chamber 8 and kiln chamber 10) arranged side-by-side and connected by a central passage 9. Each kiln is divided into a preheating zone, a calcination zone, and a cooling zone from top to bottom. The upper part of the preheating zone is equipped with a long, downward-pointing spray gun 5 extending into the kiln via a flange. Above the spray gun 5 is the stone material surface 4. A discharge platform 11 is located at the bottom of the kiln, and a discharge gate is located below the discharge platform 11 at the bottom of the kiln. A natural fan 1 connects to kiln chamber 8 via a combustion air duct. Both kiln chambers 8 and 10 have a reversing valve at the top of their exhaust pipes, which then connect to a flue gas dust collector 2. Figure 1 As shown, the spray gun is a crucial calcination device in a double-chamber kiln, with an average service life of approximately two years. As the spray gun wears down and shortens, the kiln's preheating zone shifts upwards, leading to higher temperatures in the kiln top, furnace shell, and exhaust gas. Insufficient preheating results in suboptimal product quality, and the sealing rings at the kiln's unloading platform become undercooked, causing high ash temperatures and burnt-out rubber rings. To ensure stable product quality and normal equipment operation, the spray gun needs to be replaced regularly.

[0003] Replacing the entire kiln spray lance requires shutting down and purging the entire double-chamber kiln for approximately 20 days, severely impacting stable production. Furthermore, the shutdown, purging, and kiln maintenance incur significant costs related to kiln repair, fuel consumption, and waste material generation. Therefore, the more advanced method for replacing spray lances in double-chamber kilns is "single-chamber ignition replacement," which involves changing the spray lance without completely purging the kiln. The specific procedure is as follows (using the replacement of the No. 1 kiln spray lance as an example): 1) During the kiln reversal process in kiln chamber 8 of kiln 1, cut off the fuel supply to the double-chamber kiln and stop the kiln; 2) Start the unloading platform 11 to discharge the stone material from kiln chamber 1 to the lower part of the spray gun head; 3) Open the gate of the reversing valve 3 of kiln chamber 2 to the horizontal position, close the unloading gate 12, and insulate kiln chamber 2 of kiln 10; 4) Remove the spray gun flange from the outside of the kiln and pull out the spray gun 5 that needs to be replaced in kiln chamber 8 of kiln 1; 5) Install the prepared spray gun 5 and fix the spray gun flange; 6) Because the stone material newly added to the kiln is not in a hot and high-temperature state and does not meet the ignition conditions, fuel cannot be directly sent into the kiln chamber through the spray gun 5; at this time, the kiln chamber needs to be filled with stone material before normal kiln operation, and fuel is input into kiln chamber 2 of kiln 10 to calcine the stone material; the flue gas after combustion enters kiln chamber 10 of kiln 1 through the intermediate channel to preheat the stone material in kiln chamber 1. 7) When entering the combustion period of kiln chamber 8 in kiln 1, do not allow fuel to enter kiln chamber 8 in kiln 1; that is, during the combustion period of kiln chamber 1 (the combustion capacity is set to 400-450 tons / day, each cycle is about 14 minutes, and the regenerator is fed three times during the period), shut down the fuel system; let the interface combustion time continue to run; 8) Repeat this process, that is, when kiln chamber 10 in kiln 2 of the double kiln is burning, open the fuel system; when kiln chamber 8 in kiln 1 is burning, shut down the fuel system; 9) Until the thermocouple temperature of the spray gun in kiln chamber 1 reaches 600℃, resume normal production of fuel input in kiln chamber 8 in kiln 1, that is, normal alternating periodic combustion of the two chambers; 10) After the re-ignition and re-airing operation, it takes about 8-10 hours for the thermocouple temperature of the spray gun in kiln chamber to reach 600℃; 11) After the quality of each kiln is normal, start to implement the same operation on kiln chamber 2, and replace spray gun 5 in kiln chamber 10 in kiln chamber 2.

[0004] Replacing a spray lance in a kiln and restoring normal fuel supply to that kiln takes approximately 8-10 hours. During this time, the lack of fuel supply to the kiln causes continuous uneven material distribution, affecting calcination and furnace temperature recovery, resulting in significant waste of time, heat, and material resources. Therefore, the entire operation needs further optimization to reduce this time, increase kiln thermal recovery time, and reduce waste generated by the kiln. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a rapid ignition and re-airing method for pulverized coal double-chamber kilns, so as to solve the problems of long spray gun replacement cycle, large amount of waste and large waste of resources in existing double-chamber kilns.

[0006] To solve the above problems, the technical solution of the present invention is: the rapid re-ignition and re-airing method for a pulverized coal double-chamber kiln includes the following steps:

[0007] A. Three to five cycles before stopping the fuel input of kiln No. 1, increase the coal powder input of kiln No. 2 by 10% to 15% above the normal value, while keeping the coal powder input of kiln No. 1 unchanged.

[0008] B. Before the reversal time begins, cut off the pulverized coal input to the double-chamber kiln and shut down the kiln, with kiln No. 1 serving as the combustion chamber.

[0009] C. Start the unloading platform to discharge the material, and discharge the stone material in kiln No. 1 to the lower part of the spray gun head;

[0010] D. Turn off the flue gas dust collector and stop the combustion fan that blows air into the double-chamber kiln; open the gate of the reversing valve of kiln No. 2 to the horizontal position, and at the same time close the unloading gate and the maintenance doors of the unloading platform to keep kiln No. 2 warm.

[0011] E. Pull out the spray gun that needs to be replaced from the kiln chamber No. 1 and put the prepared spray gun into the kiln chamber.

[0012] F. Fill kiln chamber 1 with stone material, covering the position above the spray gun; adjust the coal powder input to the initial set value, where the initial set value is 0-10% less than the normal value; set the kiln capacity to 400-450 tons / day and the cycle to 90-100 cycles / day; start the kiln and input fuel into kiln chamber 2 to calcine the stone material; the flue gas after combustion passes through the middle channel to store heat in the stone material in kiln chamber 1;

[0013] G. When the No. 1 kiln enters the combustion period, adjust the coal powder input to 30% to 50% of the normal value to send coal powder fuel into the No. 1 kiln; repeat this process until the thermocouple temperature of the spray gun in the kiln reaches 600℃, then restore the fuel input to the No. 1 kiln. That is, the coal powder amount of both the No. 1 and No. 2 kilns is set to the normal value during normal production, and the two kilns alternate periodically for combustion; after 50 to 70 minutes, the thermocouple temperature at the bottom of the spray gun head reaches 600℃, and the kiln quickly enters the normal calcination state;

[0014] H. After the finished product quality in kiln chambers 1 and 2 is normal, the same operation is carried out on kiln chamber 2, and the spray gun in kiln chamber 2 is replaced.

[0015] A more specific solution to the above technical solution could be: in step G, the total coal powder input of the combined coal powder input of kiln chamber 1 and kiln chamber 2 is 1.3 to 1.5 times the normal coal powder input value of one kiln chamber.

[0016] Furthermore: In step A, the normal value for the amount of pulverized coal input is 110-120 kg / ton of finished lime, and the calorific value of the pulverized coal is 6200-7500 kcal / kg.

[0017] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0018] This rapid ignition and reheating method for a pulverized coal double-chamber kiln increases the normal heat consumption of kiln No. 1 during the 3-5 cycles before changing the spray lance, allowing kiln No. 2 to better achieve its heat storage and insulation function. By injecting an appropriate amount of pulverized coal into kiln No. 1, some pulverized coal can enter kiln No. 2 through the channel, where it is calcined under the action of the high-temperature aggregate in kiln No. 2. Furthermore, some pulverized coal remaining on the surface of the aggregate in kiln No. 1 can serve as an ignition source, accelerating the preheating of the aggregate in kiln No. 1. This method ensures rapid recovery while preventing agglomeration of the aggregate in kiln No. 2. Using this method maximizes the preheating efficiency of the aggregate in kiln No. 1 while preventing kiln caking caused by prolonged calcination in kiln No. 2. The time from changing the spray lance in one kiln to restoring normal fuel supply to that kiln can be reduced to 1 hour, a reduction of approximately 6-8 hours compared to the original method. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a double-chamber kiln according to an embodiment of the present invention;

[0020] The diagram shows: 1. Combustion fan; 2. Flue gas dust collector; 3. Reversing valve; 4. Stone material surface; 5. Spray gun; 6. Spray gun thermocouple; 7. Kiln chamber No. 1; 8. Intermediate passage; 9. Kiln chamber No. 2; 10. Unloading platform; 11. Unloading gate. Detailed Implementation

[0021] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0022] Example 1:

[0023] like Figure 1 The method for rapid re-ignition and re-airing of a pulverized coal double-chamber kiln, as shown, includes the following steps:

[0024] A. Three cycles before stopping the fuel input of kiln 1 chamber 8, increase the coal powder input of kiln 2 chamber 10 by 10% above the normal value, that is, from 120 kg / ton of lime to 132 kg / ton of lime. The calorific value of coal powder is 6500 kcal / kg. The coal powder input of kiln 1 chamber remains unchanged.

[0025] B. Before the reversal time begins, cut off the pulverized coal input to the double-chamber kiln and shut down the kiln, with kiln chamber No. 1 serving as the combustion chamber.

[0026] C. Start the unloading platform 11 and the ash discharge platform to discharge the material, and discharge the stone material surface 4 of kiln chamber 8 to the lower part of the spray gun head.

[0027] D. Turn off the flue gas dust collector 2 and stop the combustion fan 1 that blows air into the double-chamber kiln; open the gate of the reversing valve 3 of kiln chamber 10 to the horizontal position, and at the same time close the unloading gate 12 and the maintenance doors of the unloading platform to keep kiln chamber 10 of kiln chamber 2 warm.

[0028] E. Remove the spray gun flange from the outside of the kiln, pull out the spray gun 5 that needs to be replaced from the kiln chamber 8, install the prepared spray gun into the kiln chamber, and fix the spray gun flange.

[0029] F. Fill kiln 1, chamber 8 with stone material, covering the area above spray gun 5, i.e., covering the top of the spray gun box; set the kiln capacity to 400 tons / day, with 100 cycles / day, and adjust the pulverized coal input to 90% of the normal value, i.e., 110 kg / ton of finished lime (if the kiln capacity is 400 tons, the cycle is set to 100 cycles / day, then the capacity per cycle is 4 tons, and the pulverized coal input per cycle is set to 120 kg / ton of finished lime, then the pulverized coal transported per cycle is 480 kg). Start the kiln, allowing fuel to be input into kiln chamber 2, chamber 10, to calcine the stone material; the flue gas after combustion passes through the intermediate channel 9 to store heat in kiln chamber 1, chamber 8.

[0030] G. When kiln chamber 8 of kiln 1 enters the combustion period, adjust the coal powder input to 50% of the normal value, i.e., 60 kg / ton of finished lime (so that the total coal powder input of the two chambers is 1.4 times the normal coal powder input of one kiln chamber, i.e., 180 kg / ton of lime), so that the coal powder fuel is fed into kiln chamber 8 of kiln 1; repeat this process, i.e., when calcining in kiln chamber 10 of the double-chamber kiln, adjust the coal powder input to 110 kg / ton of finished lime, and calcine the finished product; when calcining in kiln chamber 8 of kiln 1, adjust the coal powder input to 60 kg / ton of finished lime; until the temperature of the thermocouple 6 of the spray gun in that kiln chamber reaches 600℃, then restore the fuel input to kiln chamber 8 of kiln 1, i.e., the normal production coal powder amount of both kilns is set to 120 kg / ton of lime, i.e., the two chambers are normally alternately cyclically burned; within 70 minutes, the temperature of the thermocouple at the bottom of the spray gun 5 head can reach 600℃, so that the kiln can quickly enter the normal calcination state.

[0031] H. After the finished products in kiln chamber 8 of kiln chamber 1 and kiln chamber 10 of kiln chamber 2 are of normal quality, the same operation is carried out on kiln chamber 12 of kiln chamber 2, and the spray gun 5 of kiln chamber 2 is replaced.

[0032] Example 2:

[0033] like Figure 1 The method for rapid re-ignition and re-airing of a pulverized coal double-chamber kiln, as shown, includes the following steps:

[0034] A. Five cycles before stopping the fuel input in kiln 1 chamber 8, increase the pulverized coal input in kiln 2 chamber 10 by 15% above the normal value, that is, from 110 kg / ton of lime to 126 kg / ton of lime. The calorific value of pulverized coal is 7500 kcal / kg. The pulverized coal input in kiln 1 remains unchanged.

[0035] B. Before the reversal time begins, cut off the pulverized coal input to the double-chamber kiln and shut down the kiln, with kiln chamber No. 1 serving as the combustion chamber.

[0036] C. Start the unloading platform 11 and the ash discharge platform to discharge the material, and discharge the stone material surface 4 of kiln chamber 8 to the lower part of the spray gun head.

[0037] D. Turn off the flue gas dust collector 2 and stop the combustion fan 1 that blows air into the double-chamber kiln; open the gate of the reversing valve 3 of kiln chamber 10 to the horizontal position, and at the same time close the unloading gate 12 and the maintenance doors of the unloading platform to keep kiln chamber 10 of kiln chamber 2 warm.

[0038] E. Remove the spray gun flange from the outside of the kiln, pull out the spray gun 5 that needs to be replaced from the kiln chamber 8, install the prepared spray gun into the kiln chamber, and fix the spray gun flange.

[0039] F. Fill kiln 1, chamber 8 with stone material, covering the area above spray gun 5, i.e., covering the top of the spray gun box; set the kiln capacity to 450 tons / day, with 90 cycles / day, and adjust the pulverized coal input to 90% of the normal value, i.e., 120 kg / ton of finished lime (if the kiln capacity is 450 tons, the cycle is set to 90 cycles / day, then the capacity per cycle is 4.05 tons, and the pulverized coal input per cycle is set to 110 kg / ton of finished lime, then the pulverized coal transported per cycle is 445.5 kg). Start the kiln, allowing fuel to be input into kiln chamber 2, chamber 10, to calcine the stone material; the flue gas after combustion passes through the intermediate channel 9 to store heat in the stone material in kiln chamber 1, chamber 8.

[0040] G. When kiln chamber 8 of kiln 1 enters the combustion period, adjust the coal powder input to 30% of the normal value, i.e., 30 kg / ton of finished lime (so that the total coal powder input of the two chambers is 1.3 times the normal coal powder input of one kiln chamber, 130 kg / ton of lime), so that the coal powder fuel is fed into kiln chamber 8 of kiln 1; repeat this process, i.e., when calcining in kiln chamber 10 of the double-chamber kiln, adjust the coal powder input to 120 kg / ton of finished lime, and calcine the finished product; when calcining in kiln chamber 8 of kiln 1, adjust the coal powder input to 30 kg / ton of finished lime; until the temperature of the thermocouple 6 of the spray gun in that kiln chamber reaches 600℃, then restore the fuel input to kiln chamber 8 of kiln 1, i.e., the normal coal powder input of both kilns is set to 110 kg / ton of lime, i.e., the two chambers are normally alternately cyclically burned; within 70 minutes, the temperature of the thermocouple at the bottom of the spray gun 5 head can reach 600℃, so that the kiln can quickly enter the normal calcination state.

[0041] H. After the finished products in kiln chamber 8 of kiln chamber 1 and kiln chamber 10 of kiln chamber 2 are of normal quality, the same operation is carried out on kiln chamber 12 of kiln chamber 2, and the spray gun 5 of kiln chamber 2 is replaced.

[0042] This rapid ignition and reheating method for a pulverized coal double-chamber kiln increases the normal heat consumption of kiln No. 1 during the 3-5 cycles before changing the spray lance, allowing kiln No. 2 to better achieve its heat storage and insulation function. By injecting an appropriate amount of pulverized coal into kiln No. 1, some pulverized coal can enter kiln No. 2 through the channel, where it is calcined under the action of the high-temperature aggregate in kiln No. 2. Furthermore, some pulverized coal remaining on the surface of the aggregate in kiln No. 1 can serve as an ignition source, accelerating the preheating of the aggregate in kiln No. 1. This method ensures rapid recovery while preventing agglomeration of the aggregate in kiln No. 2. Using this method maximizes the preheating efficiency of the aggregate in kiln No. 1 while preventing kiln caking caused by prolonged calcination in kiln No. 2. The time from changing the spray lance in one kiln to restoring normal fuel supply to that kiln can be reduced to 1 hour, a reduction of approximately 6-8 hours compared to the original method.

Claims

1. A method for rapid re-ignition and re-airing in a pulverized coal double-chamber kiln, characterized in that... Includes the following steps: A. Three to five cycles before stopping the fuel input of kiln No. 1, increase the coal powder input of kiln No. 2 by 10% to 15% above the normal value, while keeping the coal powder input of kiln No. 1 unchanged. B. Before the reversal time begins, cut off the pulverized coal input to the double-chamber kiln and shut down the kiln, with kiln No. 1 serving as the combustion chamber. C. Start the unloading platform to discharge the material, and discharge the stone material in kiln No. 1 to the lower part of the spray gun head; D. Turn off the flue gas dust collector and stop the combustion fan that blows air into the double-chamber kiln; open the gate of the reversing valve of kiln No. 2 to the horizontal position, and at the same time close the unloading gate and the maintenance doors of the unloading platform to keep kiln No. 2 warm. E. Pull out the spray gun that needs to be replaced from the kiln chamber No. 1 and put the prepared spray gun into the kiln chamber. F. Fill kiln chamber 1 with stone material, covering the position above the spray gun; adjust the coal powder input to the initial set value, where the initial set value is 0-10% less than the normal value; set the kiln capacity to 400-450 tons / day and the cycle to 90-100 cycles / day; start the kiln and input fuel into kiln chamber 2 to calcine the stone material; the flue gas after combustion passes through the middle channel to store heat in the stone material in kiln chamber 1; G. When the No. 1 kiln enters the combustion period, adjust the coal powder input to 30% to 50% of the normal value to send coal powder fuel into the No. 1 kiln; repeat this process until the thermocouple temperature of the spray gun in the kiln reaches 600℃, then restore the fuel input to the No. 1 kiln. That is, the coal powder amount of both the No. 1 and No. 2 kilns is set to the normal value during normal production, and the two kilns alternate periodically for combustion; after 50 to 70 minutes, the thermocouple temperature at the bottom of the spray gun head reaches 600℃, and the kiln quickly enters the normal calcination state; H. After the finished product quality in kiln chambers 1 and 2 is normal, the same operation is carried out on kiln chamber 2, and the spray gun in kiln chamber 2 is replaced.

2. The rapid re-ignition and re-airing method for a pulverized coal double-chamber kiln according to claim 1, characterized in that: In step G, the total coal powder input of kiln chamber 1 and kiln chamber 2 is 1.3 to 1.5 times the normal coal powder input value of one kiln chamber.

3. The rapid re-ignition and re-airing method for a pulverized coal double-chamber kiln according to claim 2, characterized in that: In step A, the normal value for the amount of pulverized coal input is 110-120 kg / ton of finished lime, and the calorific value of the pulverized coal is 6200-7500 kcal / kg.

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