Dry quenching hoist monitoring system and hoist safety monitoring method

Abstract

This invention relates to a monitoring system for a dry quenching coke elevator. The monitoring system includes a set of current detection elements, two drum scales for measuring the weight of the coke cans during the elevator operation, a rail scale for measuring the weight of the coke can transport vehicle under the elevator derrick, and key limit switches along the elevator's path. The current detection elements are installed at the input end of the elevator motor cables to measure the input current of each elevator motor. The drum scales are installed under the wire rope drums on each side, the rail scale for the transport vehicle is installed directly below the elevator derrick, and the key limit switches are installed in the elevator derrick to detect the elevator's position. This technical solution enables monitoring of the entire operation process of the dry quenching coke elevator, preventing accidents from occurring or escalating.

Description

Technical Field

[0001] This invention relates to a monitoring system and safety monitoring method for a dry quenching coke elevator, belonging to the field of electrical equipment control technology. Background Technology

[0002] The coke oven dry quenching elevator is used to lift coke cans from the coke can transport vehicle to the top of the dry quenching tower, and then transfer the red-hot coke from the cans through the bottom gate into the dry quenching cooling tower. The elevator structure is as follows: Figure 1 As shown. During the hoist's cyclical operation, at the "hook opening limit" position under the hoist derrick, the coke cans loaded with high-temperature coke on the coke can transport vehicle are lifted along the hoist derrick. After a low-speed lift past the "lower acceleration / deceleration limit," high-speed lifting begins, continuing until the "upper acceleration / deceleration limit" of the hoist, at which point low-speed lifting resumes until the "upper limit of the hoisting tower" is reached and the lifting stops. Then, the cans are moved laterally along the upper lateral track from the "hoisting tower centering limit" position, accelerating and decelerating via the "hoisting tower acceleration / deceleration limit" and "cooling tower acceleration / deceleration limit" positions respectively. The cans stop at the "cooling tower centering limit" position, and the coke cans are lowered along the cooling tower derrick from the "upper limit of the hoist" position to the "lower limit of the cooling tower." Under mechanical force, the bottom gate of the coke cans opens, completing the process of releasing red-hot coke into the dry quenching cooling tower. After the coke canister is unloaded, the hoist lifts the empty coke canister from the "lower limit of the cooling tower" position to the "upper limit of the hoist." It then moves laterally along the traverse track from the "centering limit of the cooling tower," accelerating and decelerating via the "acceleration / deceleration limit switches at the cooling tower" and "acceleration / deceleration limit switches at the hoist." It stops at the "centering limit switch" and begins unloading the empty coke canister from the "upper limit of the hoist" position down the hoist derrick. Acceleration and deceleration are controlled via the "upper acceleration / deceleration limit switches" and "lower acceleration / deceleration limit switches," stopping at the "standby limit switch." Once the empty coke canister carrier has reached the unloading position, the hoist continues unloading the empty coke canister down the hoist derrick, passing through the "landing limit switch," "landing deceleration limit switch," and "hook opening limit switch," before returning the empty coke canister to the coke canister carrier. The coke canister carrier then moves again, moving the carrier containing the red-hot coke canister to the hoist derrick for the next lifting operation. The following problems exist during the operation of the hoist:

[0003] 1. During the interaction between the hoist and the coke tank transport vehicle, the hoist system cannot detect the status of the coke tank. Even if the coke tank transport vehicle is misaligned and a coke tank transport vehicle with an empty coke tank is aligned with the hoist derrick or a transport vehicle full of hot coke is aligned with the hoist derrick, the hoist system will still follow the procedure to receive hot coke or release an empty tank, leading to a chain of safety accidents such as a full tank.

[0004] 2. When the load on the hoist changes due to problems such as skew during the coke tank hoisting process, it is impossible to quickly and effectively identify the abnormality in the process, which leads to the escalation of the accident;

[0005] 3. During fully automated operation, some abnormalities may cause shutdowns that cannot be immediately detected by monitoring personnel, leading to prolonged downtime due to accidents;

[0006] Since there is no way to automatically monitor the hoist's abnormal status throughout the entire process, close manual monitoring of the hoist's production process is required, resulting in a heavy workload for workers. Therefore, there is an urgent need for a new solution to address the aforementioned technical problems. Summary of the Invention

[0007] This invention addresses the problems existing in the prior art by providing a monitoring system for a dry quenching coke elevator. This technical solution provides a safety monitoring method to monitor the entire operation process of the dry quenching coke elevator, thereby preventing the occurrence and escalation of accidents.

[0008] To achieve the above objectives, the following technical solution is proposed: a monitoring system for a dry quenching coke hoist, comprising a set of current detection elements for collecting the current of each hoist motor, two drum scales for measuring the weight of the coke cans during hoisting, a rail scale for measuring the weight of the coke can transport vehicle under the hoist derrick, and key limit switches along the hoist's path during operation, including hook opening limit, standby position limit, upper limit of the hoisting tower, lower limit of the cooling tower, hoisting tower alignment limit, and cooling tower alignment limit. The signals from these detection elements are all connected to the hoist monitoring and control system. The current detection elements are installed at the input end of the hoist motor cable to measure the input current of each hoist motor. Let the mass of the coke tanker car be M1, the weight of the empty coke tank be M2, and the weight of the coke be M3. Then, the total weight of the coke tanker car filled with red coke, weighed by the rail scale under the hoist derrick, is M = M1 + M2 + M3. The total weight of the coke tanker car after delivering the red coke is M = M1. The total weight of the coke tanker car after receiving the empty coke tank is M = M1 + M2. The roller scales are installed under the wire rope rollers on each side. During the hoisting or lowering of coke cans, the two roller scales of the hoist convert the supporting force provided by the rollers to the coke cans into a weighing value and transmit it to the hoisting monitoring system. Ma and Mb are the net weight values ​​of the coke cans on both sides calculated by each roller scale after deducting the weight of the rollers and the lifting gear themselves. Under balanced hoisting load, the weight values ​​measured by each roller scale during the uniform lifting of a full coke can satisfy Ma = Mb = (M2 + M3) / 2, and the weight measured by each roller scale during the uniform lifting or lowering of an empty coke can is Ma = Mb = (M2) / 2. The transport vehicle rail scale is installed directly below the hoisting derrick. It has specific length requirements and can be used as an auxiliary tool to indirectly determine the alignment of the transport vehicle. Its rail length is equal to the maximum allowable movement length of the front and rear wheels when the transport vehicle is aligned under the derrick, i.e., L1 = L ± ΔL, where L1 is the length of the rail scale, L is the front and rear wheel distance of the transport vehicle, and ΔL is the allowable alignment error of the transport vehicle under the hoisting derrick. During the process of the coke can carrier arriving at the hoist derrick to receive and transport coke cans, the carrier's rail scale transmits the total weight M of the carrier to the monitoring system. The purpose of setting the rail scale length is to transmit three indicative weight values—empty, full, and empty—to the monitoring system when the coke can carrier is fully aligned. By comparing these values ​​with the weighing values ​​under normal production conditions, the monitoring system can indirectly determine whether the carrier is properly aligned and whether there are any abnormalities in its status. Key limit switches are installed in the hoist derrick to detect the hoist's position. When the coke cans are running on the hoist derrick and the traverse rail, the "hook open," "standby position," "lifting tower upper limit," and "cooling tower centering" limits are triggered according to the process. The monitoring system collects the timing of these limit triggers. Using the standard over-the-kilometer mark of each section under normal operating conditions as the x-axis, the displacement value S of the lifting device as the y-axis, and the moment the hoist leaves the hook open limit as the zero point, the following graph is obtained: Figure 3 The regional standard shown is based on the time curve.

[0009] A safety monitoring method for a dry quenching coke elevator, the method comprising the following steps:

[0010] Step 1: Safety monitoring of the handover process between the dry quenching elevator and the transport vehicle;

[0011] Step 2: Safety monitoring of the hoist during the "initial stage" of the hoist;

[0012] Step 3: Safety monitoring of the hoist during the "lifting" and "lateral movement" phases;

[0013] Step 4: Monitor the residual coke in the coke pot;

[0014] Step 5: Monitor the load of the hoist throughout the entire process.

[0015] This method utilizes the characteristics of dry quenching coke cycle production, dividing the entire process of the hoist into several stages: coke receiving preparation, initial hoisting, stable hoisting, traveling to the cooling tower, coke discharge from the cooling tower, empty tank lifting from the cooling tower, traveling to the hoisting tower, lowering to the standby position, and lowering to the hook open position. The hoist monitoring system collects various parameters during the hoist's operation and monitors the equipment's actions at each stage. Through logical operation methods, it aims to detect anomalies in a timely manner, thus monitoring the entire hoist operation process.

[0016] The specific method for achieving full-process inspection is as follows:

[0017] Step 1. Implement safety monitoring of the handover process between the dry quenching coke elevator and the transport vehicle. During the cyclic production process, under normal operating conditions and with the transport vehicle properly aligned, since the entire weight of the transport vehicle is pressed onto the rail scale through the front and rear wheels (rail scale length L1 = L ± ΔL), the weight values ​​measured at each stage of the cycle for the empty coke can transport vehicle, the transport vehicle with the empty coke can, and the transport vehicle with the red-hot coke can should be the same. Before the elevator starts receiving the coke can filled with red-hot coke, the dry quenching coke elevator monitoring system determines whether the coke receiving conditions are met based on the received rail scale value M. If M = M1 + M2 + M3 ± ΔM, where ΔM is the allowable error in the kilogram range, it means that the transport vehicle loaded with red-hot coke has arrived at the elevator derrick and the lifting operation can proceed. If M = M1 + M2 ± ΔM, it can be determined that the transport vehicle is misaligned, and the transport vehicle with the empty coke can has been aligned to the lifting position. In this case, the lifting operation cannot proceed to avoid accidents involving the delivery of empty coke cans. Before emptying the coke canisters, the receiving rail scale value (M) is used to determine if the coke loading conditions are met. If M = M1 ± ΔM, it indicates that there are no coke canisters on the coke canister transport car under the hoist derrick, and the coke canister emptying operation can proceed. If M = M1 + M2 + M3 ± ΔM, it indicates that the transport car is misaligned, with the transport car containing the red-hot coke canisters positioned at the hoisting position. In this case, the coke canister emptying operation cannot be performed to avoid a heavy canister accident. If a weighing value outside these three ranges occurs, it indicates that the transport car is still moving on the track or that the wheels are outside the rail scale range due to misalignment. In this case, the hoist, whether in the standby position or with the hook open, cannot perform coke canister emptying or coke canister loading operations to avoid collisions between the moving lifting equipment and the transport car not in the hoist derrick position.

[0018] Step 2. Implement safety monitoring of the hoist during the "initial hoisting" phase. This phase involves significant movement of the lifting equipment's mechanical structure, making it a high-risk period for malfunctions, especially during the initial hoisting stage of receiving and delivering coke cans. Problems such as hoisting track jamming and mechanical deformation can occur. The hoisting monitoring system calculates the combined value M+Ma+Mb of the track scale and drum scale during the coke can receiving and delivering process to determine if mechanical jamming is occurring. Under normal hoisting conditions, M+Ma+Mb is constant, equal to the sum of the mass of the transport vehicle, coke can, and coke. However, due to jamming and mechanical impacts, the value of M+Ma+Mb will be greater than the set value M1+M2+M3±ΔM, serving as the basis for judging mechanical malfunctions during the initial hoisting phase. Similarly, during the "lowering to the hook open position" phase, abnormalities such as hoisting track jamming and mechanical deformation will cause the value of M+Ma+Mb to be less than the set value M1+M2±ΔM, serving as the basis for judging mechanical malfunctions during this phase.

[0019] Step 3. Implement safety monitoring of the hoist during the "lifting" and "lateral movement" phases. During the hoist's cycle operation, the following processes will be performed sequentially: coke tank lifting, lateral movement to the cooling tower, coke discharge from the cooling tower, empty tank return to the hoist's upper limit, lateral movement back to the hoisting tower, and empty tank return to the standby position. Limits will be sequentially activated via hook opening, hoisting tower upper limit, and cooling tower alignment. Under the same working conditions, the time taken to traverse these sequentially arranged limit sections should be equal in different cycles. Using the standard passage mark of each section under normal working conditions as the x-axis and the displacement value S of the lifting device as the y-axis, we will obtain... Figure 3 The displacement of the hoist's lifting device corresponds to a two-dimensional coordinate system. Let the moment the hoist leaves the hook and opens the limit switch be zero, the moment it reaches the standby limit switch be T1, and the moment it reaches the upper limit of the lifting tower be T2. In different cyclical operation processes, the time Ta = T2 - T1 taken for the hoist to pass through the two limit switch intervals should be constant. Similarly, the times Tb, Tc, Td, Te, and Tf taken in the stages of "moving towards the cooling tower," "discharging coke from the cooling tower," "lifting empty cans from the cooling tower," "moving towards the lifting tower," and "lowering to the standby position" are also constant in different cyclical operation processes. Comparing the actual time taken to pass through these key limit switch intervals during production with the standard time, such as... Figure 4 As shown, if the difference exceeds the set error time threshold ΔT, the abnormal speed of the hoist in these stages can be quickly identified, and an abnormal state or shutdown alarm can be triggered. Figure 4 In the example, it can be seen that the time for lifting full and empty coke cans in the lifting tower area is significantly longer than the standard time. The reason for this is that the resistance is greater, which is caused by the friction between the lifting equipment and the derrick or the accumulation of a large amount of residual coke in the coke can.

[0020] Step 4. Monitor residual coke in the coke canisters. The coke canisters cycle through receiving hot coke and emptying them. Ideally, the weighing values ​​of the same coke canister transport vehicle with hot coke or empty coke canisters would be M1+M2+M3±ΔM or M1+M2±ΔM, respectively. However, due to the presence of residual coke in the coke canisters, the mass of coke released into the dry quenching process is less than M3. The accumulation of residual coke not only reduces the efficiency of dry quenching but also causes hot coke to overflow from the coke canisters, leading to safety accidents. Therefore, the hoist monitoring system records and calculates the weighing value M1+M2+M3±ΔM before lifting hot coke and the weighing value M1'+M2'±ΔM after lowering the empty coke canister. It calculates the difference between the weighing values ​​of the coke canister transport vehicle with hot coke and empty coke canisters. If (M1+M2+M3-M1'-M2') exceeds the tonnage-level allowable error compared to the standard value M3, an alarm for "residual coke in the coke canister" is generated.

[0021] Step 5. Achieve full-process monitoring of the hoist load. Given the cyclical nature of the hoist's operation, under the same working conditions, the torque output of the hoist's drive system at the same moment or position within any working cycle should be the same. Since the motor current and the hoist's drive system torque output are directly proportional, abnormalities during hoist operation can be detected by comparing the actual current value of the hoist's drive system with the standard recorded value. By sampling the hoist motor current and using the hoist operating time or coke tank displacement as the X-axis, the following can be obtained: Figure 5 The two-dimensional graph showing the current variation curves of the hoist at each stage is shown. Taking the moment when the hoist leaves the hook limit switch after the coke tank is fully loaded as the zero point, the hoist monitoring system compares the current values ​​measured at each moment with the standard current value for that section. If the current deviation exceeds the alarm threshold, an alarm or shutdown protection signal is generated. The comparison graph is shown below. Figure 6 As shown, the actual current is higher than the standard current during the entire descent of the empty tank. The reason for this can be analyzed as the coke tank containing a large amount of residual coke that was not introduced into the cooling tower, which causes the current of the hoist in this section to be greater than the standard value.

[0022] Compared with the prior art, the present invention has the following advantages: By monitoring the handover process, initial stage, throughput time, residual coke and load in the entire production process of the hoist, this technical solution can comprehensively and automatically detect alignment process errors, mechanical jamming, process abnormalities, off-center load, overload, residual coke and load abnormalities in the operation of the hoist in a relatively rapid and quick manner. It can quickly and accurately send alarm and interlock protection signals to the next-level control system and monitoring personnel, reduce the workload of operators and prevent the escalation of accidents. Attached Figure Description

[0023] Figure 1 Schematic diagram of the dry quenching coke elevator;

[0024] Figure 2 Hoist monitoring system structure diagram (side view and top view);

[0025] Figure 3 Regional standard pass-through time curve;

[0026] Figure 4 Comparison chart of actual transit time and standard transit time in the area;

[0027] Figure 5 Improve the standard current curve of the motor current;

[0028] Figure 6 A comparison chart of the real-time current (solid line) and standard current (dashed line) of the boosted motor.

[0029] 1- Hoisting drum; 2- Wire rope; 3- Drum support; 4- Power supply line for hoisting motor; 5- Hoisting motor; 6- Current detection element; 7- Drum scale; 8- Transport vehicle track scale. Detailed Implementation

[0030] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0031] Example 1: See Figure 2A monitoring system for a dry quenching coke hoist includes a set of current detection elements 6 for collecting the current of each hoist motor, two drum scales 7 for measuring the weight of the coke cans during hoisting, a rail scale 8 for measuring the weight of the coke can transport vehicle under the hoist derrick, and key limit switches along the hoist's route, including hook opening limit, standby position limit, upper limit of the hoisting tower, lower limit of the cooling tower, hoisting tower alignment limit, and cooling tower alignment limit. The signals from these detection elements are all connected to the hoist monitoring and control system. The current detection elements 6 are installed at the input end of the hoist motor cable to measure the input current of each hoist motor. Let the mass of the coke tanker car be M1, the weight of the empty coke tank be M2, and the weight of the coke be M3. Then, the total weight of the coke tanker car filled with red coke, weighed by the transport vehicle rail scale 8 after being aligned under the hoist derrick, is M = M1 + M2 + M3. The total weight of the transport vehicle rail scale after delivering the red coke is M = M1. The total weight of the transport vehicle rail scale after receiving the empty coke tank is M = M1 + M2. The roller scales 7 are installed under the wire rope drums on each side. During the hoisting or lowering of coke cans, the two roller scales 7 of the hoist convert the supporting force provided by the drums to the coke cans into a weighing value and transmit it to the hoisting monitoring system. Ma and Mb are the net weights of the coke cans on both sides calculated by each roller scale after deducting the weight of the drums and the lifting gear themselves. Under balanced hoisting load, the weight values ​​measured by each roller scale during the uniform lifting of a full coke can satisfy Ma = Mb = (M2 + M3) / 2, and the weights measured by each roller scale during the uniform lifting or lowering of an empty coke can are Ma = Mb = (M2) / 2. The transport vehicle rail scale 8 is installed directly below the hoisting derrick. It has specific length requirements and can be used as an auxiliary tool to indirectly determine the alignment of the transport vehicle. Its rail length is equal to the maximum allowable movement length of the front and rear wheels when the transport vehicle is aligned under the derrick, i.e., L1 = L ± ΔL, where L1 is the length of the rail scale, L is the front and rear wheel track of the transport vehicle, and ΔL is the allowable alignment error of the transport vehicle under the hoisting derrick. During the process of the coke tank carrier arriving at the hoist derrick to receive and transport coke tanks, the carrier's rail scale 8 transmits the total weight M of the carrier to the monitoring system. The purpose of setting the rail scale length is to transmit three indicative weight values—empty, full, and empty—to the monitoring system when the coke tank carrier is fully aligned. By comparing these values ​​with the weighing values ​​under normal production conditions, the monitoring system can indirectly determine whether the carrier is properly aligned and whether there are any abnormalities in its status. Key limit switches are installed in the hoist derrick to detect the position of the hoist. When the coke tanks are running on the hoist derrick and the traverse rail, the "hook open," "standby position," "lifting tower upper limit," and "cooling tower centering" limits are triggered according to the process. The monitoring system collects the timing of these limit triggers. Using the standard over-the-kilometer mark of each section under normal operating conditions as the x-axis, the displacement value S of the lifting device as the y-axis, and the moment the hoist leaves the hook open limit as the zero point, the following graph is obtained: Figure 3The regional standard shown is based on the time curve.

[0032] Reference Figure 2 A hoist detection device is added to the hoist control system. The monitoring system collects signals from several key limit positions during the operation of the hoist, such as the hook opening limit, standby position limit, upper limit of the hoist tower, lower limit of the cooling tower, centering limit of the hoist tower, and centering limit of the cooling tower. It also includes a current detection element to collect the current of each hoist motor, a roller scale to measure the weight of the coke tank on both sides during the hoisting process, and a rail scale to measure the weight of the coke tank transport vehicle under the hoist derrick.

[0033] Let the mass of the coke tanker car be M1 = 100 tons, the weight of the empty coke tank be M2 = 80 tons, and the weight of the coke be M3 = 30 tons. Then, under ideal conditions, the total weight of the coke tanker car filled with red coke, after being aligned under the hoist derrick and weighed by the car's rail scale, is M = M1 + M2 + M3 = 210 tons. After delivering the red coke, the total weight of the car weighed by the rail scale is M1 = 100 tons. After receiving the empty coke tank, the total weight of the car weighed by the rail scale is M1 + M2 = 180 tons. Assuming the wheelbase L1 of the transport vehicle is 13 meters and the allowable alignment error ΔL under the hoist derrick is 0.1 meters, the length L1 of the transport vehicle's rail scale is equal to the maximum allowable movement length of the front and rear wheels when the transport vehicle is properly aligned under the derrick, i.e., L1 = L ± ΔL = 13.1 meters. During the process of the coke tank transport vehicle arriving at the hoist derrick to receive and deliver coke tanks, the transport vehicle's rail scale will transmit the total weight M of the current transport vehicle to the monitoring system. The purpose of setting the length of the rail scale is to transmit three indicative values ​​of the coke tank transport vehicle—empty, full, and empty—to the monitoring system when the coke tank transport vehicle is fully aligned. By comparing these values ​​with the set standard values ​​of 100 tons, 180 tons, and 210 tons, the monitoring system can indirectly determine whether the transport vehicle is properly aligned and whether its status is abnormal.

[0034] During the process of lifting or lowering coke cans by the hoist, the two roller scales 7 of the hoist transmit the weighing values ​​Ma and Mb on both sides of the coke can to the monitoring system. Under the condition of balanced load of the hoist, the weight measured by each roller scale during the uniform lifting of a full coke can is Ma = Mb = (M2 + M3) / 2 = (80 + 30) / 2 = 55 tons, and the weight measured by each roller scale during the uniform lifting or lowering of an empty coke can is Ma = Mb = (M2) / 2 = 40 tons.

[0035] When the coke canister is running on the hoist derrick and traverse track, the following procedures will trigger limit switches: "hook open," "standby position," "lifting tower upper limit," and "cooling tower centering." The monitoring system collects the timing of each limit switch trigger. Using a standard pass scale for each section under normal operating conditions as the x-axis and the displacement value S of the lifting device as the y-axis, the following data is obtained: Figure 3The regional standard shown is based on the time curve.

[0036] Example 2: The method for safety monitoring of the hoist utilizes the characteristics of dry quenching coke cycle production. The entire workflow of the hoist is divided into several stages: coke receiving preparation, initial hoisting, stable hoisting, travel to the cooling tower, coke discharge from the cooling tower, empty can being lifted from the cooling tower, travel to the hoisting tower, descent to the standby position, and descent to the hook open position. The hoist monitoring system collects various parameters during the hoist's operation and monitors the equipment's actions at each stage. Logical calculations are used to promptly detect anomalies, allowing for monitoring of the entire hoist operation process. A specific example of achieving full-process monitoring is as follows:

[0037] Step 1. Implement safety monitoring of the handover process between the dry quenching elevator and the transport vehicle. Compare the real-time value measured by the rail scale with the standard weight values ​​measured at each stage during the transport vehicle's cyclical operation. Set the error range to 2%. Then, before the elevator begins receiving coke cans filled with red-hot coke, the dry quenching elevator monitoring system will monitor the weight based on the received rail scale value.

[0038] If M = M1 + M2 + M3 ± ΔM = 210 ± 4.4 tons, it indicates that the transport car loaded with red coke has arrived at the hoist derrick and hoisting operations can begin. If M = M1 + M2 ± ΔM = 180 ± 3.6 tons, it can be determined that the transport car is misaligned; the transport car with the empty coke can has been positioned at the hoisting position, and hoisting operations cannot proceed to avoid accidents involving empty coke cans. Before the hoist empties the coke can, the received M value from the rail scale is used to determine whether the coke receiving conditions are met. If M = M1...

[0039] If ±ΔM = 100 ± 2 tons, it can be determined that there are no coke cans on the coke can carrier under the hoist derrick, and the coke can be emptied. If M = M1 + M2 + M3 ± ΔM = 210 ± 4.4 tons, it can be determined that the carrier is misaligned, and the carrier containing the coke cans is aligned with the hoisting position. In this case, the coke cans cannot be emptied to avoid a heavy load accident. If the weighing value is outside these three weighing ranges, it is determined that the carrier is still moving on the track or that the wheels are outside the range of the track scale due to misalignment. In this case, the hoist, which is in the standby position or the hook is open, cannot perform the coke can emptying or filling operation to avoid a collision between the moving hoist and the carrier that is not in the hoist derrick position.

[0040] Step 2. Implement safety monitoring of the hoist during the "initial hoisting" stage. Under normal hoisting conditions without mechanical obstruction or collision, M + Ma + Mb equals the sum of the mass of the transport vehicle, coke can, and coke, i.e., the sum of the three is constant at 210 tons. However, due to obstruction and mechanical impact, the value of M + Ma + Mb will be greater than the normal value. Since there is variable speed movement during the "initial hoisting" stage, assuming an allowable error of 5%, M + Ma + Mb > 210 + 210 * 5% = 220 tons. This is used as the basis for judging whether a mechanical failure has occurred during the initial hoisting stage. Similarly, during the "lowering to the hook open position" stage, due to abnormalities such as hoist track obstruction and mechanical deformation, the value of M + Ma + Mb will be < 180 + 180 * 5% = 189 tons. This is used as the basis for judging whether a mechanical failure has occurred during the lowering to the hook open position stage.

[0041] Step 3. Implement safety monitoring of the hoist during the "lifting" and "lateral movement" phases. Using the standard crossing marks of each section under normal operating conditions as the x-axis and the displacement value S of the hoisting device as the y-axis, the following results will be obtained: Figure 3 The displacement of the hoist's lifting device corresponds to a two-dimensional coordinate system. Let the moment the hoist leaves the hook and opens the limit switch be zero, the moment it reaches the standby limit switch be T1 = 0 minutes 30 seconds, and the moment it reaches the upper limit of the lifting tower be T2 = 3 minutes 5 seconds. In different cyclical operation processes, the time taken for the hoist to pass through the two limit switch intervals, Ta = T2 - T1 = 155 seconds, should be constant. Similarly, the times taken for the stages "moving towards the cooling tower," "discharging coke from the cooling tower," "lifting empty cans from the cooling tower," "moving towards the lifting tower," and "lowering to the standby position," are Tb = 50 seconds, Tc = 35 seconds, Td = 65 seconds, Te = 45 seconds, and Tf = 150 seconds, respectively. Comparing the actual time taken to pass through these key limit switch intervals during production with the standard time, such as... Figure 4 As shown, if the difference exceeds the set threshold, the abnormal speed of the hoist in these stages can be quickly identified, and an abnormal status or shutdown alarm can be triggered. Figure 4 In the example, it can be seen that the time for lifting a full coke tank (Ta = T2 - T1 = 180 seconds) and emptying the coke tank (Tf = 170 seconds) in the lifting tower area is significantly higher than the standard time of 155 seconds and 150 seconds, respectively. Both exceed the allowable error time threshold ΔT = ±5 seconds. The reason for this is that the resistance increases due to the friction between the lifting device and the derrick or the accumulation of a large amount of residual coke in the coke tank.

[0042] Step 4. Monitor residual coke in the coke cans. Ideally, the weighing values ​​of the same coke can transport vehicle, whether it has red-hot coke cans or empty coke cans, are M1+M2+M3±ΔM=210±210*2% tons or M1+M2±ΔM=180±180*2%. However, due to the presence of residual coke in the coke cans, the mass of coke released into the dry quenching process is less than M3=30 tons. The accumulation of residual coke not only reduces the efficiency of dry quenching but also causes red-hot coke to overflow from the coke cans, leading to safety accidents. Therefore, the hoist monitoring system records and calculates the weighing value M1+M2+M3±ΔM before lifting the red-hot coke and the weighing value M1'+M2'±ΔM after lowering the empty coke can. It then calculates the difference in weighing value between the coke can carrying the red-hot coke and the empty coke can. If M1+M2+M3-M1'-M2'=25 tons is greater than the standard value M3=30 tons (30-25=5 tons), exceeding the tonnage allowable error (ΔM=210*2%=4.2 tons), an alarm for "residual coke in the coke can" is generated.

[0043] Step 5. Achieve full-process monitoring of the hoist load. By sampling the hoist motor current, and using the hoist running time or coke tank displacement as the X-axis, the following can be obtained: Figure 5 The two-dimensional graph showing the current variation curves of the hoist at each stage is shown. Taking the moment when the hoist leaves the hook limit switch after the coke tank is fully loaded as the zero point, the hoist monitoring system compares the current values ​​measured at each moment with the standard current value for that section. If the current deviation exceeds the alarm threshold, an alarm or shutdown protection signal is generated. The comparison graph is shown below. Figure 6 As shown, the actual current of 360A during the entire descent of the empty canister is 9% higher than the standard current of 330A. This exceeds the set threshold of 5%. The reason for this can be analyzed as the presence of a large amount of residual coke in the canister that was not introduced into the cooling tower, causing the hoist current to exceed the standard value in this section. This embodiment illustrates the application of comparing actual and standard values ​​during hoist operation. Alarm values ​​and thresholds can vary depending on different operating conditions. Any method that compares measured values ​​with standard values ​​at various stages of hoist operation to generate alarms and protection is within the scope of patent protection described in this technology.

Claims

1. A method for safety monitoring of a dry quenching hoist, characterized in that, A dry quenching coke hoist monitoring system is adopted. The monitoring system includes a set of current detection elements, two drum scales to measure the weight of the coke cans during hoisting, a rail scale to measure the weight of the coke can transport vehicle under the hoist derrick, and key limit switches along the hoist's route. The current detection elements are installed at the input end of the hoist motor cables to measure the input current of each hoist motor. The drum scales are installed under the wire rope drums on each side, and the rail scale for the transport vehicle is installed directly below the hoist derrick. The key limit switches are installed in the hoist derrick to detect the position of the hoist. The key limit switches include hook opening limit, standby position limit, upper limit of the hoisting tower, lower limit of the cooling tower, hoisting tower centering limit, and cooling tower centering limit. The signals from these detection elements are all connected to the hoist monitoring and control system. The method includes the following steps: Step 1: Safety monitoring of the handover process between the dry quenching elevator and the transport vehicle; Step 2: Safety monitoring of the hoist during the "initial stage" of the hoist; Step 3: Safety monitoring of the hoist during the "lifting" and "lateral movement" phases; Step 4: Monitor the residual coke in the coke pot; Step 5: Monitor the load of the hoist throughout the entire process; Step 1, safety monitoring of the handover process between the dry quenching elevator and the transport vehicle, is as follows: During the cyclic production process, under normal operating conditions and with the transport vehicle properly aligned, all the weight of the transport vehicle rests on the rail scale via the front and rear wheels. The length of the rail scale is L1 = L ± ΔL. L1 is the length of the rail scale, L is the front and rear wheel track of the transport vehicle, and ΔL is the allowable alignment error of the transport vehicle under the hoist derrick. Before the hoist begins receiving coke cans filled with red-hot coke, the dry quenching hoist monitoring system determines whether the receiving conditions are met based on the received value M from the rail scale. If M = M1 + M2 + M3 ± ΔM, where ΔM is the allowable error in the kilogram range, M is the total weight weighed by the rail scale of the transport vehicle, M1 is the mass of the coke can transport vehicle, M2 is the weight of the empty coke can, and M3 is the weight of the coke, then the transport vehicle loaded with red-hot coke has arrived at the hoist derrick and the hoisting operation can proceed. If M = M1 + M2 ± ΔM, it is determined that the transport vehicle is misaligned, with the transport vehicle carrying the empty coke can being aligned with the hoisting position, and the hoisting operation cannot proceed to avoid accidents involving empty coke cans. Similarly, before the hoist empties the coke can, the system also determines whether the receiving conditions are met based on the received value M. The M value of the track scale is used to determine whether the coke loading conditions are met. If M = M1 ± ΔM, it means there are no coke cans on the coke can transport car under the hoist derrick, and the coke cans can be emptied. If M = M1 + M2 + M3 ± ΔM, it means the transport car is misaligned, and the transport car containing the coke cans is aligned with the hoisting position. In this case, the coke cans cannot be emptied to avoid a heavy load accident. If the weighing value is outside these three weighing ranges, it means the transport car is still moving on the track or the wheels are outside the range of the track scale due to misalignment. In this case, the hoist, which is in the standby position or the hook is open, cannot empty or fill the coke cans to avoid a collision between the moving hoist and the transport car that is not in the hoisting derrick position.

2. The dry quenching hoist safety monitoring method according to claim 1, characterized in that, Step 2: Safety monitoring of the hoist during the "initial hoisting" phase is as follows: The hoisting monitoring system determines mechanical obstruction issues by calculating the sum of the values ​​M+Ma+Mb of the rail scale and drum scale during the hoist's connection and delivery of coke cans. Here, Ma and Mb are the net weight values ​​of both sides of the coke can after deducting the weight of the drums and lifting gear from the weights of the drums and lifting gear, respectively. M is the total weight measured by the rail scale of the transport vehicle. Under normal hoisting conditions, M+Ma+Mb is constant, equal to the sum of the mass of the transport vehicle, the coke can, and the coke. However, due to obstruction and mechanical impact issues, the value of M+Ma+Mb will exceed the set value M1+M2+M3±ΔM (normal value). This serves as the basis for judging whether a mechanical failure has occurred during the initial lifting stage of the hoist. Similarly, during the "lowering to the hook open position" stage, due to the hoist track jamming and abnormal mechanical deformation, the value of M+Ma+Mb will be less than the set value M1+M2±ΔM. This serves as the basis for judging whether a mechanical failure has occurred during the hoist lowering to the hook open position stage.

3. The dry quenching hoist safety monitoring method according to claim 2, characterized in that, Step 3: Safety monitoring of the hoist during the "lifting" and "lateral movement" phases, as detailed below: During the cycle operation of the hoist, the following processes will be performed sequentially: hoisting the coke can, lateral movement to the cooling tower, coke discharge from the cooling tower, returning the empty can to the upper limit of the hoist, lateral movement back to the hoisting tower, and emptying the can to the standby position. This will be achieved by sequentially opening the limit switch on the hook, moving it to the upper limit of the hoisting tower, and then aligning it to the centering limit switch on the cooling tower. Under the same working conditions, the time taken to pass through these sequentially arranged limit switch intervals should be equal in different cycles. Using the standard passage time of each section under normal working conditions as the x-axis and the displacement value S of the hoisting device as the y-axis, a two-dimensional coordinate system corresponding to the hoisting device displacement and time will be obtained. Let the time when the hoist leaves the hook and opens the limit switch be zero, the time when it reaches the standby limit switch be T1, and the time when it reaches the empty can return to the upper limit switch be T2. The moment when the upper limit of the tower is reached is T2. In different cycle operation processes, the time Ta = T2 - T1 taken by the hoist to pass through these two limit intervals should be constant. Similarly, the times Tb, Tc, Td, Te, and Tf taken in the stages of "moving towards the cooling tower", "discharging coke from the cooling tower", "lifting empty can from the cooling tower", "moving towards the hoisting tower" and "lowering to the standby position" are also constant in different cycle operation processes. By comparing the actual time of passing through these key limit intervals in the production process with the standard time, if the difference exceeds the set error time threshold ΔT, the speed abnormality of the hoist in these stages can be quickly determined, and an abnormal status or shutdown alarm can be triggered.

4. The dry quenching hoist safety monitoring method according to claim 3, characterized in that, Step 4: Monitoring of residual coke in the coke cans, specifically as follows: The coke cans cycle through receiving hot coke and emptying them. Ideally, the weighing values ​​of the same coke can transport vehicle with hot coke or empty coke cans are M1+M2+M3±ΔM or M1+M2±ΔM, respectively. The hoist monitoring system records and calculates the weighing value M1+M2+M3±ΔM before hoisting the hot coke and the weighing value M1'+M2'±ΔM after releasing the empty coke can. It calculates the difference between the weighing values ​​of the coke can transport vehicle with hot coke and with only empty coke cans. If (M1+M2+M3-M1'-M2') exceeds the tonnage-level allowable error compared to the standard value M3, an alarm "residual coke in the coke can" is generated.

5. The safety monitoring method for a dry quenching coke elevator according to claim 4, characterized in that, in step 5, the full-process monitoring of the elevator load is as follows: by sampling the current of the elevator motor, with the elevator running time or coke tank displacement as the X-axis, a two-dimensional graph of the current change curve of the elevator at each stage can be obtained. Taking the moment when the elevator leaves the hook limit switch after the full coke tank is lifted as the zero point, the elevator monitoring system compares the current value measured at each moment with the standard current value of the section. If the current deviation exceeds the alarm threshold, an alarm or shutdown protection signal is generated.

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