A method for feeding raw materials in a high-capacity state of a shaft kiln
By improving the feeding trolley and optimizing the raw material process, the problem of insufficient raw materials under high capacity conditions of the sleeve kiln was solved, achieving high capacity operation and reduced energy consumption.
Patent Information
- Application Number
- CN202510533121.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-11-03
AI Technical Summary
Insufficient raw material feeding during high-capacity operation of the sleeve kiln prevents further capacity increases, causing the material level inside the kiln to drop and high-temperature gas to fill the top of the kiln, increasing equipment risk, necessitating production reduction, and keeping costs high.
By improving the feeding trolley and optimizing the raw material feeding process, including lightweighting the trolley, increasing the frequency of the winch, optimizing the feeding process and quality management, we can ensure that the raw material supply meets the demand for high production capacity.
This enabled high-capacity operation of the sleeve kiln, reduced process energy consumption, avoided equipment risks, and reduced the need for externally purchased metallurgical lime.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to an improvement method, specifically a method for improving raw material feeding in a high-capacity kiln, belonging to the field of alloy lime production control technology. Background Technology
[0002] Currently, the designed capacity of sleeve kilns in the industry is insufficient, with the load generally around 90%, making full-load production impossible. One major factor is that after capacity increases, the high material level is insufficient, the material level inside the kiln decreases, and the raw material consumption for output capacity exceeds the amount of raw material entering the kiln. As the material in the upper part of the kiln decreases, the rising high-temperature gas fills the top of the kiln, increasing the kiln top temperature and equipment risk, forcing a reduction in production. Therefore, the capacity cannot be increased, leading to the purchase of metallurgical lime or the addition of metallurgical lime production lines, resulting in a significant increase in the cost of metallurgical lime. Summary of the Invention
[0003] This invention addresses the technical problems existing in the prior art by providing a method for improving raw material feeding in a sleeve kiln under high production capacity. This solution improves the feeding trolley and optimizes the raw material feeding process, thereby solving the problem that the existing design feeding capacity cannot meet the raw material demand under high production capacity, achieving high production capacity operation of the sleeve kiln and reducing process energy consumption.
[0004] To achieve the above objectives, the technical solution of the present invention is as follows: a method for improving raw material feeding in a high-capacity kiln, the method comprising the following steps:
[0005] Step 1: Calculate the daily production capacity and raw material requirements of the sleeve kiln to obtain the raw material limestone requirement corresponding to the required output. The production capacity of this invention corresponds to 1.1 times the designed capacity. Taking the raw material requirement for increasing from 500TPD to 550TPD as an example: Limestone is the main raw material for producing lime. It is assumed that 1.78-1.85 tons of limestone are needed to produce 1 ton of active lime (the amount of limestone varies due to differences in purity and loss on ignition, and the average value of 1.8 tons / ton of lime is used here as an example).
[0006] If the daily lime production is 500 tons, then the daily limestone consumption is 500 × 1.8 = 900 tons.
[0007] If the daily lime production is 550 tons, then the daily limestone consumption is 550 × 1.8 = 990 tons.
[0008] Step 2: Review the feeding speed and feeding time interval of the raw material trolley, and then determine the minimum feeding amount required for each trolley hopper based on the daily raw material feeding amount;
[0009] Full production operation data (500 TPD) Single bucket feed capacity (t) 2.5 Feeding cycle (min) 4 Winch operating frequency (Hz) 40 Feed rate (TPD) 900
[0010] With a daily lime production of 500 tons, the trolley's loading capacity = raw material demand / 24 hours / loading times per hour = 900 / 24 / 15 = 2.5 tons.
[0011] With a daily lime production capacity of 550 tons, the trolley's loading capacity = raw material demand / 24 hours / loading times per hour = 990 / 24 / 15 = 2.75 tons.
[0012] Step 3: Compare the existing hopper loading capacity with the required feeding capacity. Generally, the existing hopper design capacity is less than the actual demand under 1.1 times the production capacity. Under normal circumstances, taking 500TPD as an example, the trolley feeding capacity is about 2.4 tons, which is less than the demand of 2.75 tons.
[0013] Cart loading capacity = Raw material demand / 24 hours / Loading times per hour = 990 / 24 / 15 = 2.75 tons
[0014] Step 4: Modify the feeding trolley, implementing lightweight and high-strength treatment to reduce its weight by more than 15%. Simultaneously, compare the weight reduction of the trolley with the increased capacity of the single bucket of limestone. If the weight reduction is greater than the increased capacity, the requirements are met; if it is less than the increased capacity of the single bucket of limestone, a redesign is necessary. The modification of the trolley's hopper is a crucial step, requiring design considerations such as material selection, impact resistance, and structure. For example, with the original trolley weight of 1.4 tons, a weight reduction of approximately 0.2 tons can be achieved.
[0015] Step 5: Re-calculate the feeding track and wire rope of the feeding trolley to determine whether they meet the mechanical requirements. From the current design of the sleeve kiln, the conditions are basically met.
[0016] Step 6: Optimize the trolley loading process and hopper preparation to reduce loading interval time. The original loading process design logic is as follows: when the trolley descends below the limestone hopper, a stop signal is issued. The limestone in the raw material bin is conveyed to the hopper via a belt conveyor by a vibrating feeder. The hopper is loaded with the set amount of raw limestone. Once the set requirements are met, the vibrating feeder stops, the belt stops, the hopper gate opens, and the limestone is placed into the trolley. After the material is discharged, the gate closes, and the trolley moves upward. The whole process takes about 30 seconds. This process time seriously affects the increase in production capacity. The improvement is that after the trolley starts lifting, the hopper is loaded immediately, reducing the waiting time of the trolley. When the trolley descends directly below the hopper, a stop signal is issued, and the hopper immediately issues a discharge command, placing the raw limestone into the trolley. The whole process optimization saves 30 seconds.
[0017] Step 7: Increase the operating frequency of the winch from 40-50Hz to 35-45Hz, shorten the feeding cycle from 4′10″-4′ to 3′40″-3′50″, and the daily feeding capacity can reach 975t;
[0018] Step 8: Track the high material level in the sleeve kiln. Based on the signals from the material level probe inside the kiln, including high and low material level signals, adjust the amount of raw material fed into the hopper. After the basic production capacity is set, if the material level is normal after 40 hours of operation, it can be basically determined that the amount of raw material fed meets the corresponding set production capacity requirements. If there is no high material level, it means that the amount of material fed is too small, so increase the amount of material fed by the trolley.
[0019] Step 9: Strengthen the quality management of raw materials, reduce the mud and sand content and the amount of crushed stone in the raw limestone, and the particle size should be controlled between 40-80. The mud and sand ratio should be less than 3%. The raw material vibrating screen should be a bar screen to ensure smooth flow of raw limestone in the raw material silo, reduce downtime, and reduce impact on high production.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: First, it does not require modification of the feeding steel structure and wire rope, saving a lot of modification costs; second, the lightweight modification of the trolley uses high-strength steel, and at the same time the structure is optimized, so that the overall weight does not increase with the increase in volume. Detailed Implementation
[0021] To enhance understanding of the present invention, detailed descriptions are provided below in conjunction with embodiments.
[0022] Example: A method for improving raw material feeding in a high-capacity kiln, the method comprising the following steps:
[0023] Example: A steel plant's demand for lime production capacity increased, and the existing capacity could not meet the requirements, so it was forced to invest in a new lime kiln with a capacity of 300 tons / day.
[0024] Another steel plant, also facing insufficient capacity, expanded its 500-ton / day lime kiln to a 600-ton / day lime kiln.
[0025] Step 1: Calculate the daily production capacity and raw material requirements of the sleeve kiln to obtain the raw material limestone requirement corresponding to the required output. The production capacity of this invention corresponds to 1.1 times the designed capacity. Taking the raw material requirement for increasing from 500TPD to 550TPD as an example: Limestone is the main raw material for producing lime. It is assumed that 1.78-1.85 tons of limestone are needed to produce 1 ton of active lime (the amount of limestone varies due to differences in purity and loss on ignition, and the average value of 1.8 tons / ton of lime is used here as an example).
[0026] If the daily lime production is 500 tons, then the daily limestone consumption is 500 × 1.8 = 900 tons.
[0027] If the daily lime production is 550 tons, then the daily limestone consumption is 550 × 1.8 = 990 tons.
[0028] Step 2: Review the feeding speed and feeding time interval of the raw material trolley, and then determine the minimum feeding amount required for each trolley hopper based on the daily raw material feeding amount;
[0029] Full production operation data (500 TPD) Single bucket feed capacity (t) 2.5 Feeding cycle (min) 4 Winch operating frequency (Hz) 40 Feed rate (TPD) 900
[0030] With a daily lime production of 500 tons, the trolley's loading capacity = raw material demand / 24 hours / loading times per hour = 900 / 24 / 15 = 2.5 tons.
[0031] With a daily lime production capacity of 550 tons, the trolley's loading capacity = raw material demand / 24 hours / loading times per hour = 990 / 24 / 15 = 2.75 tons.
[0032] Step 3: Compare the existing hopper loading capacity with the required feeding capacity. Generally, the existing hopper design capacity is less than the actual demand under 1.1 times the production capacity. Under normal circumstances, taking 500TPD as an example, the trolley feeding capacity is about 2.4 tons, which is less than the demand of 2.75 tons.
[0033] Cart loading capacity = Raw material demand / 24 hours / Loading times per hour = 990 / 24 / 15 = 2.75 tons
[0034] Step 4: Modify the feeding trolley, implementing lightweight and high-strength treatment to reduce its weight by more than 15%. Simultaneously, compare the weight reduction of the trolley with the increased capacity of the single bucket of limestone. If the weight reduction is greater than the increased capacity, the requirements are met; if it is less than the increased capacity of the single bucket of limestone, a redesign is necessary. The modification of the trolley's hopper is a crucial step, requiring design considerations such as material selection, impact resistance, and structure. For example, with the original trolley weight of 1.4 tons, a weight reduction of approximately 0.2 tons can be achieved.
[0035] Step 5: Re-calculate the feeding track and wire rope of the feeding trolley to determine whether they meet the mechanical requirements. From the current design of the sleeve kiln, the conditions are basically met.
[0036] Step 6: Optimize the trolley loading process and hopper preparation to reduce loading interval time. The original loading process design logic is as follows: when the trolley descends below the limestone hopper, a stop signal is issued. The limestone in the raw material bin is conveyed to the hopper via a belt conveyor by a vibrating feeder. The hopper is loaded with the set amount of raw limestone. Once the set requirements are met, the vibrating feeder stops, the belt stops, the hopper gate opens, and the limestone is placed into the trolley. After the material is discharged, the gate closes, and the trolley moves upward. The whole process takes about 30 seconds. This process time seriously affects the increase in production capacity. The improvement is that after the trolley starts lifting, the hopper is loaded immediately, reducing the waiting time of the trolley. When the trolley descends directly below the hopper, a stop signal is issued, and the hopper immediately issues a discharge command, placing the raw limestone into the trolley. The whole process optimization saves 30 seconds.
[0037] Step 7: Increase the operating frequency of the winch from 40-50Hz to 35-45Hz, shorten the feeding cycle from 4′10″-4′ to 3′40″-3′50″, and the daily feeding capacity can reach 950-975t;
[0038] Step 8: Track the high material level in the sleeve kiln. Based on the signals from the material level probe inside the kiln, including high and low material level signals, adjust the amount of raw material fed into the hopper. After the basic production capacity is set, if the material level is normal after 40 hours of operation, it can be basically determined that the amount of raw material fed meets the corresponding set production capacity requirements. If there is no high material level, it means that the amount of material fed is too small, so increase the amount of material fed by the trolley.
[0039] Step 9: Strengthen the quality management of raw materials, reduce the mud and sand content and the amount of crushed stone in the raw limestone, and the particle size should be controlled between 40-80. The mud and sand ratio should be less than 3%. The raw material vibrating screen should be a bar screen to ensure smooth flow of raw limestone in the raw material silo and reduce downtime.
[0040] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.
Claims
1. A method for improving raw material feeding in a high-capacity kiln, characterized in that, The method includes the following steps: Step 1: Calculate the daily production capacity and raw material requirements of the sleeve kiln to determine the required limestone demand corresponding to the required output. Step 2: Review the feeding speed and feeding time interval of the raw material trolley, and then determine the minimum feeding amount required for each trolley hopper based on the daily raw material feeding amount; Step 3: Compare the existing hopper loading capacity with the required loading capacity. Under normal circumstances, the trolley loading capacity is about 2.4 tons, which is less than the required 2.75 tons. The trolley's loading capacity = raw material demand / 24 hours / number of loading times per hour = 990 / 24 / 15 = 2.75 tons. Step 4: Modify the feeding trolley, making it lightweight and high-strength, so that the weight of the trolley is reduced by more than 15%. At the same time, compare the weight reduction of the trolley with the increase in the single bucket of limestone after the increase in production capacity. If it is greater than the increase in weight, the requirements are met. If it is less than the increase in the single bucket of limestone, it must be redesigned. Step 5: Re-calculate and verify the loading track and wire rope of the loading trolley to determine whether the wire rope and loading track meet the upper limit of the load-bearing capacity after the weight of the trolley plus the added material is increased. Step 6: Optimize the trolley loading process, prepare materials in the hopper, and reduce loading interval time. Step 7: Increase the operating frequency of the winch. Step 8: Track the high material level in the sleeve kiln. Step 9: Strengthen the quality management of raw materials. The main aspects of quality management are to reduce the content of mud and sand, reduce the proportion of small-diameter limestone, increase the permeability of the kiln, and meet the requirements of rapid material flow in the kiln, so as to create raw material conditions for increased production.
2. The method for improving raw material feeding in a high-capacity kiln as described in claim 1, characterized in that, Step 1: Calculate the daily production capacity and raw material requirements of the sleeve kiln to determine the required limestone demand corresponding to the desired output. The production capacity is 1.1 times the designed capacity. Limestone is the main raw material for lime production. Assume that 1.78-1.85 tons of limestone are needed to produce 1 ton of quicklime. If the daily lime production is 500 tons, then the daily limestone consumption = 500 × 1.8 = 900 tons. If the daily lime production is 550 tons, then the daily limestone consumption is 550 × 1.8 = 990 tons.
3. The method for improving raw material feeding in a high-capacity kiln as described in claim 1, characterized in that, Step 2: Review the feeding speed and feeding time interval of the raw material trolley, and then determine the minimum feeding amount required for each trolley hopper based on the daily raw material feeding amount; For a daily lime production of 500 tons, the trolley loading capacity = raw material demand / 24 hours / loading times per hour = 900 / 24 / 15 = 2.5 tons. For a daily lime production of 550 tons, the trolley loading capacity = raw material demand / 24 hours / loading times per hour = 990 / 24 / 15 = 2.75 tons.
4. The method for improving raw material feeding in a high-capacity kiln as described in claim 1, characterized in that, Step 6: Optimize the trolley loading process and hopper preparation to reduce loading interval time. The original loading process design logic was as follows: when the trolley descends below the limestone hopper, a stop signal is issued. The limestone in the raw material silo is conveyed to the hopper via a belt conveyor by a vibrating feeder. The hopper is loaded with the set amount of raw limestone. Once the set requirements are met, the vibrating feeder stops, the belt stops, the hopper gate opens, and the limestone is placed into the trolley. After the material is discharged, the gate closes, and the trolley moves upward. The entire process takes about 30 seconds. This process time seriously affects the increase in production capacity. The improvement is that after the trolley starts lifting, the hopper is immediately loaded, reducing the waiting time of the trolley. When the trolley descends directly below the hopper, a stop signal is issued, and the hopper immediately issues a discharge command, placing the raw limestone into the trolley. The entire process optimization saves 30 seconds.
5. The method for improving raw material feeding in a high-capacity kiln as described in claim 1, characterized in that, Step 7: Increase the operating frequency of the winch from 35-45Hz to 40-50Hz, shorten the feeding cycle from 4′10″-4′ to 3′40″-3′50″, and the daily feeding capacity can reach 950-975t.
6. The method for improving raw material feeding and lifting in a high-capacity kiln as described in claim 1, characterized in that, Step 8: Track the high material level in the sleeve kiln. Based on the signals from the material level probe inside the kiln, including high and low material level signals, adjust the amount of raw material fed into the hopper. After the basic production capacity is set, if the material level is normal after 40 hours of operation, it can be basically determined that the amount of raw material fed meets the corresponding set production capacity requirements. If there is no high material level, it means that the amount of material fed is too small, so increase the amount of material fed by the trolley.
7. The method for improving raw material feeding in a high-capacity kiln as described in claim 1, characterized in that, Step 9: Strengthen the quality management of raw materials, reduce the mud and sand content and the amount of crushed stone in the raw limestone, and the particle size should be controlled between 40-80 mm. The mud and sand ratio should be less than 3%. The raw material vibrating screen should be a bar screen to ensure good screening quality of raw limestone, remove mud and sand, and ensure that the limestone particles entering the lime kiln are uniform in size, so that the flow inside the kiln is smooth and the output is improved.