Automatic control system of annular lump ore dryer

Abstract

The invention relates to an automatic control system of an annular lump ore dryer. The control system comprises a lump ore feeding surge bin, an adjustable hydraulic baffle used for adjusting the opening degree of a gate of the feeding surge bin, a plurality of belt conveyors, a belt conveyor electronic scale, a high-temperature flue gas air pipe, an electromagnetic valve used for controlling the flow of high-temperature flue gas, and a front thermometer used for measuring the temperature of flue gas at a high-temperature flue gas inlet of the dryer. The flow monitor is used for measuring the flue gas flow at a high-temperature flue gas inlet of the dryer; the thermometer is used for measuring the internal temperature of the ring type dryer; the scanner is used for measuring the thickness of a lump mineral aggregate layer; the rear thermometer is used for measuring the flue gas temperature at the high-temperature flue gas outlet of the dryer; the heating effect and the drying quality uniformity are improved by controlling the thickness of the lump mineral aggregate layer, the automation degree is high, multiple links are automatically controlled, and manual intervention and errors are reduced.

Description

Technical Field

[0001] This invention relates to a control system, specifically an automatic control system for a ring-shaped lump ore dryer, belonging to the technical field of ironmaking control systems. Background Technology

[0002] Lump ore is one of the main raw materials for blast furnace ironmaking, and the lower its powder content, the better it is for blast furnace production. To improve the screening effect of lump ore and reduce the proportion of powder in the lump ore after screening, many domestic steel companies dry and heat the lump ore before screening to reduce its moisture content and improve the screening effect. Because the lump ore is conveyed to the dryer by belt conveyor, its uneven distribution on the dryer trolley affects the drying effect. If a leveling mechanism is used to level the lump ore, it is prone to jamming and wears out quickly, requiring a lot of manpower for maintenance. Increasing the flue gas temperature or flow rate to improve the drying effect may result in energy waste and excessively high flue gas temperature, which could ignite the dust collector bags. Therefore, a new solution is urgently needed to solve this technical problem. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing an automatic control system for a ring-shaped lump ore dryer. In a ring-shaped lump ore dryer, the drying effect of the lump ore is affected by multiple factors, including the moisture content of the lump ore before drying, the flow rate and temperature of the high-temperature flue gas, the thickness of the lump ore layer, and the ambient temperature. This invention uses a PLC system to automatically adjust multiple parameters such as the material layer thickness, the rotation speed of the ring dryer trolley, the flue gas temperature, and the opening of the buffer hopper, ensuring that the temperature difference of the high-temperature flue gas before and after drying is stabilized within the range required by the process, thereby achieving the goal of easy screening of the dried lump ore.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: an automatic control system for a ring-shaped lump ore dryer, characterized in that the control system includes a lump ore feeding buffer bin, an adjustable hydraulic baffle for adjusting the opening of the feeding buffer bin gate, several belt conveyors, a belt conveyor electronic scale, a high-temperature flue gas duct and a solenoid valve for controlling the flow rate of the high-temperature flue gas, a pre-thermometer for measuring the flue gas temperature at the inlet of the dryer, a flow monitor for measuring the flow rate of the flue gas at the inlet of the dryer, a ring dryer, a thermometer for measuring the internal temperature of the ring dryer, a scanner for measuring the thickness of the lump ore layer, and a system for... The system includes a rear thermometer for measuring the flue gas temperature at the high-temperature flue gas outlet of the dryer, a high-temperature flue gas outlet, and a PLC control system; an adjustable hydraulic baffle is installed at the opening of the lump ore feed buffer bin to adjust the gate opening; after the gate opens, the material in the bin falls onto the belt conveyor, which transports the material to the dryer; an electronic scale for the belt conveyor is installed at the belt head pulley; a front thermometer is installed at the high-temperature flue gas inlet of the dryer; a rear thermometer is installed at the high-temperature flue gas outlet; a scanner for measuring the thickness of the lump ore layer is installed on the top cover of the dryer after the material surface has stabilized; and a solenoid valve for controlling the flow rate of the high-temperature flue gas is installed on the pipe used to input the high-temperature flue gas.

[0005] An automatic control system for a ring-shaped lump ore dryer, the control method is as follows:

[0006] Step 1: Process startup, belt conveyor start-up, and ring dryer trolley start-up.

[0007] Step 2: Introduce high-temperature flue gas at a certain flow rate and fixed temperature, and the annular dryer begins preheating.

[0008] Step 3: After a delay, the thermometer measuring the internal temperature of the ring dryer returns the internal temperature T1 until this temperature reaches the discharge process requirements.

[0009] Step 4: The adjustable hydraulic baffle at the outlet of the lump ore buffer bin opens to a certain degree, and the lump ore begins to be discharged into the ring dryer. Step 5: After a delay, two thermometers used to measure the temperature difference ΔT at the inlet and outlet of the high-temperature flue gas in the dryer are used to monitor the temperature. The PLC automatically determines whether ΔT is within acceptable limits based on the previously input ΔT standard range. If it is within acceptable limits, return to Step 4; otherwise, proceed to the next step.

[0010] Step 6: The flow monitoring instrument used to measure the flow rate of the high-temperature flue gas at the inlet of the dryer provides feedback on the input flow rate of the high-temperature flue gas. The PLC system determines whether the inlet flue gas flow rate is within the acceptable range based on the pre-input flow rate. If it is acceptable, proceed to the next step; if it is unacceptable, increase the opening L1 of the solenoid valve controlling the flow rate of the high-temperature flue gas, and return to Step 6 again.

[0011] Step 7: The scanner used to measure the thickness of the lump ore layer sends feedback of the lump ore layer thickness to the PLC system. It then determines whether the layer thickness H is acceptable. If acceptable, the rotation speed r of the ring dryer is increased to reduce the layer thickness, thereby improving the heating effect of the lump ore, and the process returns to step 5. If unacceptable, proceed to step 8.

[0012] Step 8: The scanner used to measure the thickness of the lump ore layer provides feedback on the lump ore layer thickness H. The PLC automatically determines whether H is within the standard range based on the previously input thickness value H. If it is within the acceptable range, the dryer trolley speed r is increased to reduce the thickness of the material layer, thereby improving the heating effect of the lump ore, and the process returns to Step 5. If it is not within the acceptable range, the buffer chamber gate opening L is adjusted, and after a delay, the process returns to Step 5.

[0013] Step 9: After the operation is completed, stop feeding material and turn off the machine.

[0014] Compared to existing technologies, this invention has the following advantages: 1. Regarding improved drying effect, the preheating of the ring dryer creates a suitable temperature environment for drying lump ore. Monitoring the temperature difference ΔT between the inlet and outlet of the high-temperature flue gas in the dryer ensures full utilization of heat; 2. By controlling the thickness of the lump ore layer, the heating effect and the uniformity of drying quality are improved; 3. In terms of ease of control, the high degree of automation, with automatic control of multiple stages, reduces manual intervention and errors. Key parameters are fed back in real time, and the PLC system adjusts accordingly, such as adjusting the opening of the solenoid valve, the opening of the buffer chamber gate, and the dryer speed. The operation process is clear and easy for operators to master, ensuring operational accuracy and consistency, reducing operational difficulty and error rate, and keeping the drying process in optimal operating condition at all times. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall control process of the present invention. Detailed Implementation

[0016] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0017] Example 1: See Figure 1 An automatic control system for a ring-shaped lump ore dryer includes a lump ore feed buffer bin, an adjustable hydraulic baffle for adjusting the opening of the feed buffer bin gate, several belt conveyors, belt conveyor electronic scales, a high-temperature flue gas duct and a solenoid valve for controlling the flow rate of the high-temperature flue gas, a front thermometer for measuring the flue gas temperature at the inlet of the dryer, a flow monitor for measuring the flow rate of the flue gas at the inlet of the dryer, a ring dryer, a thermometer for measuring the internal temperature of the ring dryer, a scanner for measuring the thickness of the lump ore layer, a rear thermometer for measuring the flue gas temperature at the outlet of the dryer, a high-temperature flue gas outlet, and a PLC control system.

[0018] The ring dryer trolley is driven by a variable frequency motor, allowing adjustment of the rotational speed (r) to control the material layer thickness. The trolley consists of five parts: a frame, baffles, rollers, grate bars, and a movable sliding plate (upper sliding plate). High-temperature flue gas can heat the lump ore through the gaps on the trolley surface. A front thermometer 1 is installed at the high-temperature flue gas inlet to monitor the inlet temperature, and a rear thermometer 2 is installed at the high-temperature flue gas outlet to monitor the outlet temperature. Ideally, the difference between the two thermometers should be within the range of 170-185℃ to achieve the desired drying effect for the lump ore. The flue gas generated during the drying process is treated by a bag filter and then returned to the recovery bin.

[0019] The automatic control system for a ring-shaped lump ore dryer, as described above, includes the following steps:

[0020] 1. Process start-up: belt conveyor starts, and ring dryer trolley starts.

[0021] 2. A preferred method is to introduce high-temperature flue gas at a certain flow rate and fixed temperature, with the flue gas temperature being 260℃ and the initial flow rate being 50,000 m³ / h. 3 / min, the ring dryer begins preheating.

[0022] 3. After a delay, the thermometer measuring the internal temperature of the ring dryer returns the internal temperature T1 until the temperature reaches the discharge process requirements. As a preferred option, the internal temperature T1 of the ring dryer is 120-130℃, which meets the process requirements.

[0023] 4. The adjustable hydraulic baffle at the outlet of the lump ore buffer bin opens to a certain degree, and the lump ore begins to be discharged into the ring dryer. As a preferred option, the outlet opening of the lump ore buffer bin is adjusted to 220mm.

[0024] 5. After a delay, two thermometers used to measure the temperature difference ΔT at the inlet and outlet of the high-temperature flue gas in the dryer are used to monitor the temperature. The PLC automatically determines whether ΔT is within acceptable limits based on the previously input ΔT standard range. If it is within acceptable limits, return to step 4; otherwise, proceed to the next step. As a preferred option, the temperature difference ΔT is set to 170-185℃.

[0025] 6. A flow monitor for measuring the flow rate of high-temperature flue gas at the inlet of the dryer provides feedback on the input flow rate of the high-temperature flue gas. The PLC system determines whether the inlet flue gas flow rate is within acceptable limits based on the pre-input flow rate range. If it is acceptable, proceed to the next step; if it is unacceptable, increase the opening L1 of the solenoid valve controlling the flow rate of the high-temperature flue gas and return to step 6. As a preferred option, the high-temperature flue gas flow rate is set to 100,000 m³ / h. 3 / min-110000m 3 / min.

[0026] 7. The scanner used to measure the thickness of the lump ore layer feeds back the lump ore layer thickness to the PLC system to determine whether the layer thickness H is qualified. If qualified, the rotation speed r of the ring dryer is increased to reduce the layer thickness, thereby improving the heating effect of the lump ore, and the process returns to step 5; if unqualified, the process proceeds to the next step. As a preferred option, the layer thickness H is set to 120mm-150mm.

[0027] 8. The belt conveyor electronic scale used to measure the lump ore flow rate provides feedback on the lump ore flow rate Q. The PLC automatically determines whether Q is within the standard range input earlier. If it is within the acceptable range, the dryer trolley speed r is increased to reduce the material layer thickness, thereby improving the heating effect of the lump ore, and the process returns to step 5. If it is not within the acceptable range, the buffer bin gate opening L is adjusted, and the process returns to step 5 after a delay. Preferably, the lump ore flow rate Q is set within the range of 400t / h-500t / h, the trolley speed r is set within the range of 18° / min-22° / min, and the buffer bin gate opening L is set within the range of 180mm-220mm.

[0028] 9. After the operation is completed, stop feeding material. After the remaining material has been discharged, close the high-temperature flue gas solenoid valve and shut down the system.

[0029] 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. An automatic control system for a ring-shaped lump ore dryer, characterized in that, The control system includes a lump ore feed buffer bin, an adjustable hydraulic baffle for adjusting the opening of the feed buffer bin gate, several belt conveyors, belt conveyor electronic scales, high-temperature flue gas ducts and solenoid valves for controlling the flow rate of high-temperature flue gas, a front thermometer for measuring the flue gas temperature at the inlet of the dryer, a flow monitor for measuring the flow rate of flue gas at the inlet of the dryer, a ring dryer, a thermometer for measuring the internal temperature of the ring dryer, a scanner for measuring the thickness of the lump ore layer, a rear thermometer for measuring the flue gas temperature at the outlet of the dryer, a high-temperature flue gas outlet, and a PLC control system. An adjustable hydraulic baffle is installed at the opening of the lump ore feed buffer bin to adjust the gate opening. After the gate is opened, the material in the bin falls onto the belt conveyor and is transported to the dryer. The belt conveyor electronic scale is installed at the belt head pulley. The front thermometer is installed at the high-temperature flue gas inlet of the dryer, and the rear thermometer is installed at the high-temperature flue gas outlet. A scanner for measuring the thickness of the lump ore layer is installed on the top cover of the dryer after the material surface is stable. A solenoid valve for controlling the flow rate of high-temperature flue gas is installed on the pipeline for inputting high-temperature flue gas.

2. The automatic control system for the annular lump ore dryer according to claim 1, characterized in that, The control method is as follows: Step 1: Process startup, belt conveyor start-up, and ring dryer trolley start-up. Step 2: Introduce high-temperature flue gas at a certain flow rate and fixed temperature, and the annular dryer begins preheating. Step 3: After a delay, the thermometer measuring the internal temperature of the ring dryer returns the internal temperature T1 until this temperature reaches the discharge process requirements. Step 4: The adjustable hydraulic baffle at the outlet of the lump ore buffer bin opens to a certain degree, and the lump ore begins to be discharged into the ring dryer. Step 5: After a delay, two thermometers used to measure the temperature difference ΔT at the inlet and outlet of the high-temperature flue gas in the dryer are used to monitor the temperature. The PLC automatically determines whether ΔT is within acceptable limits based on the previously input ΔT standard range. If it is within acceptable limits, return to Step 4; otherwise, proceed to the next step. Step 6: The flow monitoring instrument used to measure the flow rate of the high-temperature flue gas at the inlet of the dryer provides feedback on the input flow rate of the high-temperature flue gas. The PLC system determines whether the inlet flue gas flow rate is within the acceptable range based on the pre-input flow rate. If it is acceptable, proceed to the next step; if it is unacceptable, increase the opening L1 of the solenoid valve controlling the flow rate of the high-temperature flue gas, and return to Step 6 again. Step 7: The scanner used to measure the thickness of the lump ore layer sends feedback of the lump ore layer thickness to the PLC system. It then determines whether the layer thickness H is acceptable. If acceptable, the rotation speed r of the ring dryer is increased to reduce the layer thickness, thereby improving the heating effect on the lump ore, and the process returns to Step 5. If unacceptable, proceed to the next step. Step 8: The scanner used to measure the thickness of the lump ore layer provides feedback on the lump ore layer thickness H. The PLC automatically determines whether H is within the standard range based on the previously input thickness value H. If it is within the acceptable range, the dryer trolley speed r is increased to reduce the thickness of the material layer, thereby improving the heating effect of the lump ore, and the process returns to Step 5. If it is not within the acceptable range, the buffer chamber gate opening L is adjusted, and after a delay, the process returns to Step 5. Step 9: After the operation is completed, stop feeding material and turn off the machine.

3. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 2, the temperature of the high-temperature flue gas is 260℃, and the initial flow rate of the flue gas is 50,000 m³ / h. 3 / min, the ring dryer begins preheating.

4. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 3, the internal temperature T1 of the ring dryer is 120-130℃, which meets the process requirements.

5. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 4, the outlet opening of the block ore buffer bin is adjusted to 220mm.

6. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 5, the difference ΔT between the two is set to 170-185℃.

7. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 6, the high-temperature flue gas flow rate is set to 100,000 m³ / h. 3 / min-110000m 3 / min.

8. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 7, the material layer thickness H is set to 120mm-150mm.

9. The automatic control system for the annular lump ore dryer according to claim 2, characterized in that, In step 8, the set range of the block ore flow rate Q is 400t / h-500t / h, the set range of the trolley speed r is 18° / min-22° / min, and the set range of the buffer chamber gate opening L is 180mm-220mm.

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