Method for measuring and calibrating the amount of oil on the surface of a steel strip

Abstract

The application discloses a kind of steel band surface oiling quantity measurement and calibration method, comprising the following steps: S1: make the oiling machine be in offline state, by providing analog operation signal to the oiling machine to start operation;S2: the rust preventive oil output in predetermined time is collected at the oil outlet pipeline of the oiling machine;S3: based on the collected rust preventive oil amount and the parameter related to the analog operation signal, determine the actual output performance parameter of the oiling machine;S4: based on the actual output performance parameter, the control parameter of the oiling machine is corrected.The steel band surface oiling quantity measurement and calibration method of the application does not need to purchase expensive online oil film measuring instrument, only uses the existing downtime of factory, using conventional container and weighing tool can complete high-precision measurement;And directly weighing the outflow rust preventive oil, avoids the huge relative error brought by measuring trace oil film from huge steel band matrix, and the measurement result is accurate and reliable.

Description

Technical Field

[0001] This invention belongs to the field of steel strip surface treatment technology, specifically relating to a method for measuring and calibrating the amount of oil applied to the surface of a steel strip. Background Technology

[0002] In the cold rolling process of steel, to prevent the surface of the steel strip from rusting during storage or transportation, it is usually necessary to apply oil protection to its surface at the exit section of the production line. Currently, electrostatic oiling machines are commonly installed on cold rolling pickling, continuous annealing, and rewinding production lines. These machines spray a uniform and extremely thin layer of anti-rust oil film onto the upper and lower surfaces of the steel strip to achieve short-term rust prevention.

[0003] A typical electrostatic oiling system generally includes an oiling machine body, a metering pump, a blade beam, a high-voltage electrostatic generator, and an oil tank recovery device. The system is configured with a target oiling amount (e.g., 600 mg / m³) based on process requirements or the needs of different products. 2 The oiling machine calculates the required volumetric flow rate of the rust-preventive oil based on the set oiling amount, the real-time operating speed of the production line (unit: m / min), and the effective length of the blade beam (unit: mm), and then converts this into the driving speed of the metering pump. The metering pump typically has a fixed displacement per revolution (e.g., 2000 µl / rev), and the output oil volume is roughly controlled by adjusting its motor speed. The rust-preventive oil is delivered by the metering pump to the oiling blade beam installed above and below the steel strip. The blade beam is connected to a high-voltage electrostatic field, causing the outflowing rust-preventive oil to be fully atomized under the action of the high-voltage electric field and evenly adhered to the surface of the steel strip by electrostatic adsorption. To ensure coverage of the entire strip width, the blade beam length is generally slightly larger than the maximum width of the steel strip (e.g., blade beam length 1600 mm, corresponding to a maximum steel strip width of 1500 mm). Excess oil mist that does not adhere to the steel strip settles at the bottom of the oiling machine, is collected, and pumped back to the oil tank for recycling.

[0004] The system requires a series of interlocking conditions to operate: the oiling machine must be online, and the steel strip must establish stable tension and reach a certain operating speed before the oiling program can be started. However, in practical applications, the control accuracy requirements for the amount of oil applied to the steel strip surface are usually not stringent. Therefore, most existing systems adopt an open-loop control strategy, that is, they only calculate the metering pump speed based on preset parameters and theoretical models, without real-time detection and closed-loop feedback adjustment of the actual output flow of the metering pump or the final amount of oil applied to the steel strip surface.

[0005] The actual amount of oil applied to the steel belt is related to the actual amount of rust-preventive oil output by the metering pump. However, after many years of operation, it is unknown whether the amount of rust-preventive oil output per unit speed of the metering pump can be stabilized at the theoretical value. Furthermore, the flow rate and speed of the metering pump of the oiling machine are not under closed-loop control, but rather under open-loop control. Therefore, it is necessary to measure and calibrate the amount of oil applied.

[0006] To calibrate or verify the amount of oil applied, several measurement methods exist in the prior art, but all have significant limitations. One approach is to use a professional oil film thickness measuring instrument for online or offline detection. While this instrument can directly or indirectly reflect the amount of oil applied, its high purchase cost makes it inconvenient for widespread deployment and frequent use in production lines. Another alternative method is offline sampling detection: a sample of oiled steel strip is cut from the production line, its total weight is measured, the surface oil film is thoroughly removed with a cleaning solution, and after rinsing and drying, its net weight is measured again. By calculating the weight difference between the two weighings and combining it with the area of ​​the steel strip, the actual amount of oil applied per unit area of ​​that steel strip can be deduced. However, this method is cumbersome, time-consuming, and labor-intensive, and cannot achieve rapid and continuous monitoring. More importantly, because the anti-rust oil film is extremely thin, its weight accounts for a very small proportion of the weight of the steel strip substrate itself. During the weighing process, it is easily affected by environmental interference, instrument errors, and operational fluctuations, resulting in a large measurement error in the final calculation result, and insufficient reliability and practicality. Summary of the Invention

[0007] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for measuring and calibrating the amount of oil applied to the surface of a steel strip, with the goal of achieving the measurement of the amount of oil applied to the surface of the steel strip in a low-cost manner while ensuring measurement accuracy.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a method for measuring and calibrating the amount of oil applied to the surface of steel strip, comprising the following steps: S1: Put the oiling machine offline and start it up by providing a simulated operation signal; S2: Collect the rust-preventive oil output within a predetermined time at the oil outlet line of the oiling machine; S3: Based on the collected amount of rust-preventive oil and the parameters related to the simulated operation signal, determine the actual output performance parameters of the oiling machine; S4: Based on the actual output performance parameters, the control parameters of the oiling machine are corrected.

[0009] In step S1, the simulated operation signals include simulated oiling machine online signals, simulated steel belt tension establishment signals, and simulated steel belt running speed signals.

[0010] In step S3, determining the actual output performance parameters of the oiling machine specifically includes: Based on the collected amount of rust-preventive oil, the simulated running speed of the steel strip, the collection time, and the length of the oiling blade beam, the actual amount of oil applied per unit area on the surface of the steel strip is calculated.

[0011] In step S4, the correction of the control parameters of the oiling machine specifically includes: Calculate the ratio K of the actual amount of oil applied per unit area to a set amount of oil applied; The oil application amount setting value sent to the oiling machine is corrected based on the ratio K, or the theoretical unit speed output flow rate value of the metering pump in the oiling machine control program is multiplied by the ratio K.

[0012] In step S1, the step of starting the oiling machine by providing a simulated operation signal specifically involves providing a forced speed command signal to the metering pump of the oiling machine to start the metering pump.

[0013] In step S3, determining the actual output performance parameters of the oiling machine specifically includes: Based on the amount of rust-preventive oil collected, the rotational speed value corresponding to the forced rotational speed command signal, and the collection time, the actual unit rotational speed output flow rate of the metering pump is calculated.

[0014] In step S4, the correction of the control parameters of the oiling machine specifically involves: Replace the theoretical unit speed output flow rate of the metering pump used in the oiling machine control program with the calculated actual unit speed output flow rate.

[0015] In step S2, the output pipes of the metering pumps on the upper and lower surfaces of the oiling machine are disconnected, and containers are set below the output pipes to collect the output rust-preventive oil.

[0016] The actual amount of oil applied per unit area Ga is calculated using the following formula: Ga = G × 1000 ÷ (n × t × L ÷ 1000) Where G is the weight of the collected rust-preventive oil in grams; n is the simulated speed of the steel belt in meters per minute; t is the collection time in minutes; and L is the length of the oiling blade beam in millimeters.

[0017] The actual output flow rate La per unit speed is calculated using the following formula: La = L × 1000 ÷ (n × t) Where L is the volume of rust-preventive oil collected, in milliliters; n is the rotational speed value corresponding to the forced rotational speed command signal, in revolutions per minute; and t is the collection time, in minutes.

[0018] The method for measuring and calibrating the amount of oil applied to the surface of steel strips in this invention eliminates the need to purchase expensive online oil film measuring instruments. It utilizes existing factory downtime and conventional containers and weighing tools to complete high-precision measurements. Furthermore, by directly weighing the flowing rust-preventive oil, it avoids the huge relative errors caused by measuring a small amount of oil film from a large steel strip substrate, ensuring accurate and reliable measurement results. This method achieves the measurement of the amount of oil applied to the surface of steel strips in a low-cost manner while ensuring measurement accuracy. Detailed Implementation

[0019] The following description of the embodiments further illustrates the specific implementation of the present invention in detail, with the aim of helping those skilled in the art to have a more complete, accurate, and in-depth understanding of the concept and technical solution of the present invention, and facilitating its implementation. Example

[0020] This invention provides a method for measuring and calibrating the amount of oil applied to the surface of a steel strip, comprising the following steps: S1: Put the oiling machine offline and start it up by providing a simulated operation signal; S2: Collect the rust-preventive oil output within a predetermined time at the oil outlet line of the oiling machine; S3: Based on the collected amount of rust-preventive oil and parameters related to the simulated operation signal, determine the actual output performance parameters of the oiling machine; S4: Based on the actual output performance parameters, the control parameters of the oiling machine are corrected.

[0021] Specifically, in this embodiment of the invention, based on offline simulated production conditions, the actual amount of oil applied by the system is inferred by directly measuring the output oil volume, thereby correcting the control commands or parameters.

[0022] In step S1 above, the simulated operating signals include the simulated online signal of the oiling machine, the simulated steel strip tension establishment signal, and the simulated steel strip running speed signal. During the planned downtime of the production line, the oiling machine is removed from the production line, placing it in an offline, standby state.

[0023] By using external debugging tools or modifying the control logic, simulated production line operation signals are sent to the oiling machine control system. Specifically, this includes: forcing the oiling machine into an online state, simulating the sending of a "steel belt tension established" signal, and providing a constant simulated steel belt running speed (e.g., set to 100 meters / minute) and a target oil application amount setpoint (e.g., set to 600 milligrams / square meter). At this point, the oiling machine control system logically determines that all operating conditions are met and enters a standby state.

[0024] In step S2 above, a start command is sent to the oiling machine, which simulates normal production operation. The output pipes of the metering pumps on the upper and lower surfaces of the oiling machine are disconnected, and containers are placed below the output pipes to collect the output rust-preventive oil. At the same time, a timer is started to keep the oiling machine running in a stable simulated state for a preset time (e.g., 10 minutes). Then, the oiling machine is stopped and the oil collection ends. This achieves the collection of rust-preventive oil output within a predetermined time at the oil outlet of the oiling machine.

[0025] In step S3 above, the actual output performance parameters of the oiling machine are determined, specifically including: Based on the collected amount of rust-preventive oil, the simulated steel strip running speed, the collection time, and the length of the oiling blade beam, the actual oil coating amount per unit area on the steel strip surface is calculated. The actual oil coating amount Ga per unit area is calculated using the following formula: Ga = G × 1000 ÷ (n × t × L ÷ 1000) Where G is the weight of the collected rust-preventive oil in grams; n is the simulated speed of the steel belt in meters per minute; t is the collection time in minutes; and L is the length of the oiling blade beam in millimeters.

[0026] In step S4 above, the control parameters of the oiling machine are corrected, specifically including: Calculate the ratio K of the actual amount of oil applied per unit area Ga to a set amount of oil applied Gs, i.e., K = Ga / Gs; The oil application amount setting value sent to the oiler is corrected based on the ratio K, or the theoretical unit speed output flow value of the metering pump in the oiler control program is multiplied by the ratio K.

[0027] In step S4 above, two methods can be used to perform system correction: The first method is external instruction correction: In the main control system of the production line, the target oiling amount setting value to be sent to the oiling machine is corrected to the original setting value divided by K (i.e., Gs / K). At the same time, the display value fed back from the oiling machine is multiplied by the coefficient K to maintain the consistency of the human-machine interface display.

[0028] The second method is internal parameter correction: directly modify the "theoretical unit displacement of metering pump" parameter stored inside the oiling machine controller, multiplying its original value by a coefficient K. The controller will then perform all subsequent control calculations based on the corrected displacement parameter.

[0029] In this way, when the oiling machine is put into operation on the production line, the oiling amount set on the production line basically matches the actual oiling amount. The measurement and calibration of the oiling amount are completed without knowing the unit speed and flow rate of the metering pump and the density of the anti-rust oil.

[0030] The method in this embodiment achieves closed-loop calibration of the entire oiling machine system. Its advantage lies in completely bypassing dependence on the internal wear state of the metering pump and the density of the anti-rust oil, directly using the final coating effect (oil volume per unit area) as the calibration target. Through an innovative offline simulation, measurement collection, and back-calculation correction process, the complex problem of online oil film measurement is transformed into a simple offline weighing calculation problem, significantly reducing calibration costs and operational difficulty while ensuring calibration accuracy. This fundamentally solves the accuracy drift problem of open-loop control systems after long-term operation. Example

[0031] This invention provides a method for measuring and calibrating the amount of oil applied to the surface of a steel strip, comprising the following steps: S1: Put the oiling machine offline and start it up by providing a simulated operation signal; S2: Collect the rust-preventive oil output within a predetermined time at the oil outlet line of the oiling machine; S3: Based on the collected amount of rust-preventive oil and parameters related to the simulated operation signal, determine the actual output performance parameters of the oiling machine; S4: Based on the actual output performance parameters, the control parameters of the oiling machine are corrected.

[0032] Specifically, in this embodiment of the invention, a more direct calibration method is provided. The prerequisite for this method is that the amount of oil applied is calculated using the default theoretical unit speed output flow of the metering pump and matches the amount of oil applied on the production line. However, the default theoretical unit speed output flow of the metering pump may have changed, so it needs to be recalculated and calibrated.

[0033] In step S1 above, the oiling machine is taken offline and started by providing a simulated operation signal to the oiling machine. Specifically, a forced speed command signal is provided to the metering pump of the oiling machine to start the metering pump.

[0034] In step S2 above, the oiling machine simulates normal production operation. The output pipes of the metering pumps on the upper and lower surfaces of the oiling machine are disconnected, and containers are placed below the output pipes to collect the output rust-preventive oil. A constant speed command (e.g., 500 rpm) is directly applied to the metering pump that needs to be calibrated, and a timer is started simultaneously to keep the metering pump running at a fixed speed for a predetermined time (e.g., 10 minutes), collecting all the output rust-preventive oil in the containers. This achieves the collection of rust-preventive oil output within a predetermined time at the oil outlet of the oiling machine.

[0035] In step S3 above, the actual output performance parameters of the oiling machine are determined, specifically including: Based on the collected amount of rust-preventive oil, the rotational speed value corresponding to the forced rotational speed command signal, and the collection time, the actual unit speed output flow rate La (unit: μL / rpm) of the metering pump is calculated. The actual unit speed output flow rate La is calculated using the following formula: La = L × 1000 ÷ (n × t) Where L is the volume of rust-preventive oil collected, in milliliters; n is the rotational speed value corresponding to the forced rotational speed command signal, in revolutions per minute; and t is the collection time, in minutes.

[0036] In step S4 above, the control parameters of the oiling machine are corrected, specifically as follows: Replace the theoretical unit speed output flow rate of the metering pump used in the oiling machine control program with the calculated actual unit speed output flow rate.

[0037] By entering the oiling machine control program, the parameter "theoretical unit speed output flow of metering pump" used for control calculation is located, and the original theoretical default value is replaced with the La value obtained from this actual measurement calculation.

[0038] When the oiling machine is put into operation on the production line, the oiling machine control program will calculate and output a new metering pump speed setting value based on the new actual metering pump unit speed output flow value, so that the oiling amount set on the production line basically matches the actual oiling amount.

[0039] The measurement method in this embodiment has the advantage of being faster to operate, requiring only testing the pump unit without simulating the complete working logic of the oiling machine. By directly measuring and updating the performance parameters of the metering pump, it is possible to compensate for performance degradation caused by pump wear, changes in internal clearances, etc., restoring the accuracy of the control model. It eliminates the need for expensive, dedicated steel belt surface oil coating measurement instruments, and the accuracy meets process requirements.

[0040] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method of measuring and calibrating the amount of oil applied to the surface of a steel strip, characterized in that, Including the following steps: S1: Put the oiling machine offline and start it up by providing a simulated operation signal; S2: Collect the rust-preventive oil output within a predetermined time at the oil outlet line of the oiling machine; S3: Based on the collected amount of rust-preventive oil and the parameters related to the simulated operation signal, determine the actual output performance parameters of the oiling machine; S4: Based on the actual output performance parameters, the control parameters of the oiling machine are corrected.

2. The method of measuring and calibrating the oiling amount of a steel strip surface according to claim 1, characterized in that, In step S1, the simulated operation signals include simulated oiling machine online signals, simulated steel belt tension establishment signals, and simulated steel belt running speed signals.

3. The method of measuring and calibrating the amount of oil applied to the surface of a steel strip according to claim 2, wherein In step S3, determining the actual output performance parameters of the oiling machine specifically includes: Based on the collected amount of rust-preventive oil, the simulated running speed of the steel strip, the collection time, and the length of the oiling blade beam, the actual amount of oil applied per unit area on the surface of the steel strip is calculated.

4. The method of measuring and calibrating the oiling amount of a steel strip surface according to claim 3, characterized by, In step S4, the correction of the control parameters of the oiling machine specifically includes: Calculate the ratio K of the actual amount of oil applied per unit area to a set amount of oil applied; The oil application amount setting value sent to the oiling machine is corrected based on the ratio K, or the theoretical unit speed output flow rate value of the metering pump in the oiling machine control program is multiplied by the ratio K.

5. The method of measuring and calibrating the amount of oil applied to the surface of a steel strip according to claim 1, wherein In step S1, the step of starting the oiling machine by providing a simulated operation signal specifically involves providing a forced speed command signal to the metering pump of the oiling machine to start the metering pump.

6. The method for measuring and calibrating the amount of oil applied to the surface of steel strip according to claim 5, characterized in that, In step S3, determining the actual output performance parameters of the oiling machine specifically includes: Based on the amount of rust-preventive oil collected, the rotational speed value corresponding to the forced rotational speed command signal, and the collection time, the actual unit rotational speed output flow rate of the metering pump is calculated.

7. The method for measuring and calibrating the amount of oil applied to the surface of a steel strip according to claim 6, characterized in that, In step S4, the correction of the control parameters of the oiling machine specifically involves: Replace the theoretical unit speed output flow rate of the metering pump used in the oiling machine control program with the calculated actual unit speed output flow rate.

8. The method for measuring and calibrating the amount of oil applied to the surface of a steel strip according to any one of claims 1 to 7, characterized in that, In step S2, the output pipes of the metering pumps on the upper and lower surfaces of the oiling machine are disconnected, and containers are set below the output pipes to collect the output rust-preventive oil.

9. The method for measuring and calibrating the amount of oil applied to the surface of a steel strip according to claim 3 or 4, characterized in that, The actual amount of oil applied per unit area Ga is calculated using the following formula: Ga = G × 1000 ÷ (n × t × L ÷ 1000) Where G is the weight of the collected rust-preventive oil in grams; n is the simulated speed of the steel belt in meters per minute; t is the collection time in minutes; and L is the length of the oiling blade beam in millimeters.

10. The method for measuring and calibrating the amount of oil applied to the surface of a steel strip according to claim 6 or 7, characterized in that, The actual output flow rate La per unit speed is calculated using the following formula: La = L × 1000 ÷ (n × t) Where L is the volume of rust-preventive oil collected, in milliliters; n is the rotational speed value corresponding to the forced rotational speed command signal, in revolutions per minute; and t is the collection time, in minutes.