A method for measuring the quantity of molten iron in an iron ladle in a ladle-upsetting process

Abstract

The present application relates to a kind of iron ladle in the process of iron ladle turning, the molten iron quantity measuring method in iron ladle, the method includes the following steps: first, laser radar liquid level meter installation and molten iron liquid level calculation, second step: the measurement and calculation of molten iron quantity in iron ladle in the process of iron turning, third step: torpedo tank installation weighing and wireless transmitting device, fourth step; The verification determination of molten iron quantity in iron ladle in the process of "automatic" iron ladle turning.The scheme improves the safety of "automatic" iron turning technology in the process of practical application, eliminates the major production accidents of iron spilling.

Description

TECHNICAL FIELD

[0001] The present application relates to a measuring method, in particular to a molten iron quantity measuring method in a ladle turning process, and belongs to the technical field of molten iron control in metallurgical industry. BACKGROUND

[0002] The molten iron smelted in an iron plant is transported to a ladle turning station by a torpedo car, the torpedo car turns over to pour the molten iron from the torpedo into a ladle in a ladle turning pit of the ladle turning station, the ladle turning station is an important link of ladle distribution, and is a key process of a steelmaking converter smelting. At present, the ladle turning technology of some domestic steel plants has been upgraded from manual iron turning to automatic iron turning. The automatic iron turning technology liberates labor and improves the ladle turning efficiency, but does not improve the safety of the ladle turning process. In the automatic iron turning process, the molten iron weight in the ladle, the molten iron liquid level height in the ladle and the iron flow need to be detected continuously, and the detection and transmission stability of these data directly relates to the safety of the automatic iron turning. The real-time changing molten iron quantity in the ladle in the ladle turning station is an important data for the safety of the automatic iron turning, and at present, the ladle turning station of domestic and international steel plants adopts a weighing method and a liquid level height model calculation method to measure the real-time changing molten iron quantity in the ladle in the ladle turning process. However, these methods are not ideal in actual application, mainly in the following aspects: 1. The impact force of the iron flow on the molten iron in the ladle is not accurately calculated in the ladle turning process, so that the molten iron weight abnormally fluctuates in the measurement process. 2. In the ladle turning process, the smoke in the molten iron is large, so that the radar liquid level meter installed above the ladle cannot accurately detect. The above situations cause the inaccurate measurement of the real-time changing molten iron quantity in the ladle in the ladle turning process, and cause a major production accident of iron spilling or the automatic iron turning process is stopped due to the inaccurate measurement of the molten iron quantity. Therefore, if the accurate measurement of the molten iron quantity in the ladle in the ladle turning process can be solved, the safety of the automatic iron turning technology in actual application can be improved. Therefore, in order to solve the problem of the accurate measurement of the molten iron quantity in the ladle in the ladle turning process and improve the safety of the automatic iron turning technology in actual application, a ladle turning process molten iron quantity measuring and calculating method is provided. SUMMARY

[0003] The present application is exactly aimed at the problems in the prior art, and provides a ladle turning process molten iron quantity measuring method, which improves the safety of the automatic iron turning technology in actual application and eliminates a major production accident of iron spilling.

[0004] In order to achieve the above purpose, the technical scheme of the present application is as follows: a ladle turning process molten iron quantity measuring method, the method comprising the following steps:

[0005] First, the installation of the laser radar liquid level meter and the calculation of the liquid level of molten iron, as follows,

[0006] The laser radar liquid level meter is installed above the inverted pit and below the fish tank pouring hole. The radar liquid level meter installation support is made of angle steel. The installed laser radar liquid level meter can be obliquely shot into the ladle. The laser transmitter emits a laser pulse. The pulse is reflected by the molten iron surface in the ladle and received by the receiver. The distance from the pulse generator to point A in the ladle is calculated,

[0007] The liquid level of molten iron L = H3-H1-H2 Formula One

[0008] The liquid level measured by the liquid level meter H2 = L1*sinθ Formula Two

[0009] According to Formula One and Formula Two, we have:

[0010] The liquid level of molten iron L = H3-H1-L1*sinθ Formula Three

[0011] In the formula: L: actual liquid level of molten iron

[0012] H3: distance from fish tank spout to empty ladle bottom (this distance is a fixed value),

[0013] H1: distance from fish tank spout to laser radar liquid level meter horizontal height (this distance is a fixed value),

[0014] H2: liquid level meter measurement and calculation distance,

[0015] L1: actual measurement distance of laser radar liquid level meter,

[0016] θ: angle between laser radar ray and horizontal line;

[0017] Second step: measurement and calculation of the amount of molten iron in the ladle during the iron turning process, as follows,

[0018] The load sensor installed on the molten iron cross car is subjected to the combined action of the ladle, the amount of molten iron in the ladle, and the impact force of the iron flow, resulting in,

[0019] The amount of molten iron in the ladle: T = T1-T2-F Formula Four

[0020] Iron flow impact force: F = ρ*S*H4*g Formula Five

[0021] Iron flow height: H4 = H3-L Formula Six

[0022] According to Formula Three, Formula Four, Formula Five, and Formula Six, we have:

[0023] The amount of molten iron in the ladle: T = T1-T2-[p*S*(H1+L1*sinθ)]*g Formula seven

[0024] In the formula: T: the amount of molten iron in the ladle during the turning process,

[0025] T1: the display value of the weighing transmitter during the turning process,

[0026] T2: the weight of the ladle,

[0027] p: the density of molten iron,

[0028] S: the cross-sectional area of the iron flow,

[0029] H1: the horizontal distance from the torpedo tank mouth to the laser radar liquid level meter (this distance is a fixed value),

[0030] L1: the measured distance of the laser radar liquid level meter,

[0031] theta: the angle between the laser radar ray and the horizontal line,

[0032] g: the acceleration of gravity,

[0033] Step three: install the weighing and wireless transmission device on the torpedo tank, as follows,

[0034] The torpedo tank truck axle is improved, and a weighing sensor is added. The weighing sensor is installed below the rotating shaft at both ends of the torpedo tank. Three 90-ton weighing sensors are installed on each side of the axle, and the three weighing sensors are arranged horizontally. The weighing transmitter and wireless transmission device are installed on the torpedo tank truck. When the torpedo tank runs to the pouring position, the wireless transmission device sends the real-time weight T3 of the torpedo tank to the PLC system of the pouring station.

[0035] The fourth step is to check and determine the quantity of molten iron in the ladle during the automatic pouring process, and the specific method is as follows: when the operator starts the automatic pouring process, the pouring PLC starts to record the initial weight T3 of the torpedo ladle. During the automatic pouring process, the wireless sending device sends the real-time weight T3 to the pouring PLC, and the pouring PLC automatically calculates the decreasing value as At, which is one of the reference values of the quantity of molten iron in the ladle during the automatic pouring process. The quantity of molten iron T in the ladle calculated by formula seven in step two is another reference value. The radar liquid level meter installed on the inclined side of the pouring pit measures and calculates the real-time height of the liquid level of the molten iron in the ladle, and the liquid level height value is input to the PLC. According to the control logic, the quantity of molten iron T in the ladle is calculated by formula seven. At and T are mutually corrected and judged in the PLC program, and one of the effective values is taken as the feedback of the real-time quantity of molten iron in the ladle during the automatic pouring process of the torpedo ladle. During the automatic pouring process, when the effective value taken by the mutual correction and judgment in the PLC program and the real value of the quantity of molten iron in the ladle reach the pouring value set by the operator on the HMI screen or the liquid level height reaches the maximum value limited by the PLC control logic, it is determined that the automatic pouring process is completed, the torpedo ladle is returned to zero, and the automatic pouring process is completed.

[0036] Compared with the prior art, the present application has the following advantages: first, the method can accurately measure the impact force of the iron flow on the molten iron in the ladle during the pouring and iron turning process, and eliminate the influence of the impact force on the weighing of the molten iron during the weighing process; second, the installation position of the laser radar avoids the smoke generated during the pouring process, and eliminates the abnormal fluctuation of the liquid level detection data; third, the comparison and judgment of the two groups of weight data make the measurement of the real-time changing quantity of molten iron in the ladle during the iron turning process accurate, eliminate the major production accidents caused by iron spilling, improve the safety of the automatic iron turning technology in actual application, and also eliminate the abnormal alarm caused by inaccurate detection data and the abnormal zero return of the torpedo ladle, thereby improving the iron turning efficiency. The present application solves the problem of accurate measurement of the quantity of molten iron in the ladle during the pouring and iron turning process, and improves the safety of the automatic iron turning technology in actual application. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The figure is a schematic diagram of the installation position of the laser radar range finder;

[0038] Figure 2 The figure is a schematic diagram of the detection of the laser radar range finder installed in the pouring station.

[0039] In the figure, 1 is a torpedo ladle, 2 is a tapping hole, 3 is a laser radar range finder installation platform, 4 is a laser radar range finder, 5 is a ladle, and 6 is a weighing sensor.

[0040] L: the liquid level of the molten iron in the ladle;

[0041] Molten iron liquid level 1: molten iron liquid level in automatic back pouring process

[0042] Molten iron liquid level 2: molten iron liquid level in automatic back pouring process

[0043] Laser radar ranging sensor: laser radar ranging instrument installed at the back pouring station position in the present application;

[0044] θ: laser emission angle. DETAILED DESCRIPTION

[0045] In order to deepen the understanding of the present application, the present embodiment will be described in detail below in conjunction with the accompanying drawings.

[0046] Embodiment 1: A method for measuring the amount of molten iron in the ladle during the back pouring process, the method comprising the following steps:

[0047] First step, laser radar liquid level meter installation and molten iron liquid level calculation,

[0048] The laser radar liquid level meter is installed above the back pouring pit slope and located below the torpedo ladle iron pouring opening slope. An angle steel is used to make a radar liquid level meter installation support. The installed laser radar liquid level meter can be obliquely shot into the ladle at the installed position. The laser emitter emits a laser pulse. The pulse is reflected by the molten iron liquid surface in the ladle and received by the receiver. The distance from the pulse generator to point A in the ladle is calculated (such as Figure 1 ).

[0049] Molten iron liquid level L = H3-H1-H2 Formula One

[0050] Liquid level H2 measured by liquid level meter = L1*sinθ Formula Two

[0051] According to Formula One and Formula Two, we can get:

[0052] Molten iron liquid level L = H3-H1-L1*sinθ Formula Three

[0053] In the formula: L: actual molten iron liquid level

[0054] H3: distance from torpedo ladle spout to empty ladle bottom (this distance is a fixed value)

[0055] H1: distance from torpedo ladle spout to laser radar liquid level meter horizontal height (this distance is a fixed value)

[0056] H2: liquid level meter measurement and calculation distance

[0057] L1: actual measurement distance of laser radar liquid level meter

[0058] θ: laser radar ray and horizontal line angle

[0059] Second step: measurement and calculation of the amount of molten iron in the ladle during the iron pouring process,

[0060] The load sensor installed on the molten iron overpass car is affected by the iron ladle, the amount of molten iron in the iron ladle, and the impact force of the iron flow, and the following formula is obtained:

[0061] The amount of molten iron in the iron ladle: T = T1-T2-F Formula Four

[0062] Iron flow impact force: F = ρ * S * H4 * g Formula Five

[0063] Iron flow height: H4 = H3-L Formula Six

[0064] According to Formula Three, Formula Four, Formula Five, and Formula Six, we can get:

[0065] The amount of molten iron in the iron ladle: T = T1-T2-[ρ * S * (H1+L1 * sinθ)] * g Formula Seven

[0066] In the formula: T: the amount of molten iron in the iron ladle during the iron turning process

[0067] T1: the display value of the weighing transmitter during the iron turning process

[0068] T2: the weight of the iron ladle

[0069] ρ: the density of molten iron

[0070] S: the cross-sectional area of the iron flow

[0071] H1: the horizontal distance from the torpedo tank mouth to the laser radar liquid level meter (this distance is a fixed value)

[0072] L1: the measured distance of the laser radar liquid level meter

[0073] θ: the angle between the laser radar ray and the horizontal line

[0074] g: the acceleration of gravity

[0075] Step 3: Install the weighing and wireless transmission device on the torpedo tank,

[0076] Improve the torpedo car axle, add a weighing sensor, install the weighing sensor below the rotating shaft at both ends of the torpedo tank, install 3 sets of 90-ton weighing sensors on each side of the axle, and arrange the 3 sets of weighing sensors horizontally. Install the weighing transmitter and wireless transmission device on the torpedo car, and when the torpedo tank runs to the ladle position, the wireless transmission device sends the real-time weight T3 of the torpedo tank to the ladle station PLC system.

[0077] Step 4: Verification and determination of the amount of molten iron in the iron ladle during the "automatic" ladle turning process

[0078] When the "automatic iron pouring" is started by the operator of the pouring station, the pouring PLC starts to record the starting weight T3 of the torpedo tank. As the "automatic iron pouring" process proceeds, the wireless sending device sends the real-time weight T3 of the torpedo tank to the pouring PLC, which is decreasing. The pouring PLC automatically calculates the decreasing value as At, which is one of the reference values of the amount of molten iron in the ladle during the automatic pouring process. The amount of molten iron T in the ladle calculated by formula seven in step two is another reference value. The radar liquid level meter installed above the inclined pouring pit measures and calculates the real-time height of the molten iron level in the ladle. The height value of the molten iron level is given to the PLC, which calculates the amount of molten iron T in the ladle according to formula seven and the control calculation logic. At and T are mutually corrected and judged in the PLC program, and the effective value taken is real-time judged according to the control logic, which is used as the feedback of the real-time amount of molten iron in the ladle during the automatic pouring process of the torpedo tank. During the automatic pouring process, when the effective value taken by the mutual correction and judgment in the PLC program and the true value of the amount of molten iron in the ladle reach the pouring value set by the operator on the HMI screen or the liquid level height reaches the maximum value defined by the PLC control logic, it is determined that the automatic pouring is completed, the torpedo car is returned to zero, and the automatic pouring is completed.

[0079] Specific use method:

[0080] First step: select a large installation position for the laser radar liquid level meter above the inclined pouring pit. The installation position of the laser radar liquid level meter must be installed above the inclined pouring pit and below the inclined position of the torpedo tank tapping hole. The laser beam cannot be blocked by the iron flow and must be in the path with the least amount of smoke. After selecting the position, use angle steel and steel pipe to make a liquid level meter installation support, and fix the liquid level meter at an angle of θ with the horizontal direction. Use a ruler to measure the vertical distance H1 between the emission point of the laser radar liquid level meter and the torpedo tank tapping hole. The distance H3 from the torpedo tank tapping hole to the bottom of the empty ladle.

[0081] Second step: improve the torpedo car trunnion, add a weighing sensor, and install the weighing sensor below the rotating shaft at both ends of the torpedo tank. Install three 90-ton weighing sensors on each side of the trunnion, and arrange the three weighing sensors horizontally. Install a weighing transmitter and a wireless sending device on the torpedo car. When the torpedo tank runs to the pouring position, the wireless sending device sends the real-time weight T3 of the torpedo tank to the pouring station PLC system.

[0082] Third step: according to formula three: L = H3 - H1 - L1 * sinθ, program the molten iron level calculation logic program in the pouring station PLC. According to formula seven: T = T1 - T2 - [ρ * S * (H1 + L1 * sinθ)] * g, program the molten iron amount calculation logic program in the pouring station PLC.

[0083] Data processing method of correction process:

[0084] When the "automatic iron pouring" is started by the operator of the pouring station, the pouring PLC starts recording the initial weight T3 of the torpedo tank. As the "automatic iron pouring" process proceeds, the wireless sending device sends the real-time weight T3 to the pouring PLC, which is decreasing. The pouring PLC automatically calculates the decreasing value as Δt, which is one of the reference values of the molten iron quantity in the iron ladle during the automatic pouring process. The PLC calculates the molten iron quantity T in the iron ladle as another reference value. The radar liquid level meter installed above the inclined side of the pouring pit calculates the real-time height of the molten iron liquid level in the iron ladle, and the value of the molten iron liquid level height is given to the PLC, which calculates the molten iron quantity T in the iron ladle according to formula seven. The PLC reads a weighing data every second, compares the current data with the calculated value T, calculates the absolute value difference, and puts the difference into the intermediate variable storage of the difference. Δt and T are mutually corrected and discriminated in the PLC program, and one effective value is determined in real time according to the control logic, which is used as the feedback of the real-time molten iron quantity in the iron ladle during the automatic pouring process of the torpedo tank. During the automatic pouring process, when the effective value determined by the mutual correction and discrimination in the PLC program and the real value of the molten iron quantity in the iron ladle reach the pouring value set by the operator on the HMI screen or the liquid level height reaches the maximum value defined by the PLC control logic, it is determined that the automatic pouring is completed, the torpedo car is returned to zero, and the automatic pouring is completed.

[0085] It should be noted that the above embodiments are not intended to limit the scope of protection of the present application, and any equivalent transformation or substitution made on the basis of the above technical solutions falls within the scope of protection of the claims of the present application.

Claims

1. A method for measuring the quantity of molten iron in an iron ladle during a ladle reversal and iron transfer process, characterized by, The method Comprise the following steps: First, the installation of laser radar liquid level meter and molten iron liquid level calculation, Second step: measurement and calculation of the amount of molten iron in the ladle during the turning process, Third step: torpedo tank installation weighing and wireless transmission device, Fourth step: verification and determination of the amount of molten iron in the ladle during the automatic pouring process; Among them, the first step, the installation of laser radar liquid level meter and molten iron liquid level calculation, is as follows: the laser radar liquid level meter is installed above the pouring pit and below the torpedo tank pouring opening, an angle steel is used to make a radar liquid level meter installation bracket, the installed laser radar liquid level meter can be obliquely shot into the ladle, the laser transmitter emits a laser pulse, the pulse is reflected by the molten iron liquid surface in the ladle and received by the receiver, and the distance from the pulse generator to point A in the ladle is calculated, Molten iron liquid level L = H3-H1-H2 formula one; Liquid level H2 measured by liquid level meter = L1*sinθ formula two; According to formula one and formula two, we can get: Molten iron liquid level L = H3-H1-L1*sinθ formula three In the formula: L: actual molten iron liquid level, H3: the distance from the torpedo tank mouth to the empty ladle bottom, which is a fixed value, H1: the distance from the torpedo tank mouth to the horizontal height of the laser radar liquid level meter, which is a fixed value, H2: the measured distance of the liquid level meter, L1: the measured distance of the laser radar liquid level meter, θ: the angle between the laser radar ray and the horizontal line; The second step: measurement and calculation of the amount of molten iron in the ladle during the turning process, is as follows: the load sensor installed on the molten iron cross car is subjected to the combined action of the ladle, the amount of molten iron in the ladle, and the impact force of the iron flow, and the amount of molten iron in the ladle is obtained, Molten iron in the ladle: T = T1-T2-F formula four Iron flow impact force: F = ρ*S*H4*g formula five Iron flow height: H4 = H3-L formula six According to formula three, formula four, formula five and formula six, we can get: Molten iron in the ladle: T = T1-T2-[ρ*S*(H1+L1*sinθ)]*g formula seven In the formula: T: the amount of molten iron in the ladle during the turning process, T1: the display value of the weighing transmitter during the turning process, T2: the weight of the ladle, ρ: the density of molten iron, S: the cross-sectional area of the iron flow, H1: the distance from the torpedo tank mouth to the horizontal height of the laser radar liquid level meter, L1: the measured distance of the laser radar liquid level meter, θ: the angle between the laser radar ray and the horizontal line, g: the acceleration of gravity; The fourth step is to check and determine the amount of molten iron in the ladle during the automatic pouring process. When the operator starts the automatic pouring process, the pouring PLC records the initial weight T3 of the torpedo ladle. During the automatic pouring process, the wireless sending device sends the real-time weight T3 to the pouring PLC, which automatically calculates the decrease Δt. Δt is one of the reference values for the amount of molten iron in the ladle, and the amount of molten iron T calculated by formula seven in the second step is another reference value. The radar level meter installed on the inclined side of the pouring pit measures the real-time height of the molten iron level in the ladle. The height value of the molten iron level is sent to the PLC, which calculates the amount of molten iron T in the ladle according to formula seven. Δt and T are mutually corrected and judged in the PLC program, and one of the effective values is taken as the feedback of the real-time amount of molten iron in the ladle during the automatic pouring process of the torpedo ladle. During the automatic pouring process, the effective value taken by mutual correction and judgment in the PLC program and the true value of the amount of molten iron in the ladle reach the pouring value set by the operator on the HMI screen or the maximum value limited by the PLC control logic, and the automatic pouring process is completed. The torpedo ladle truck returns to zero, and the automatic pouring process is completed.

2. The method as claimed in claim 1, wherein, The third step is to install the weighing and wireless sending device on the torpedo ladle. The details are as follows: The torpedo ladle truck's trunnion is improved by adding a weighing sensor. The weighing sensor is installed below the rotating shaft at both ends of the torpedo ladle. Three 90-ton weighing sensors are installed on each side of the trunnion, and the three weighing sensors are arranged horizontally. A weighing transmitter and a wireless sending device are installed on the torpedo ladle truck. When the torpedo ladle runs to the pouring position, the wireless sending device sends the real-time weight T3 of the torpedo ladle to the pouring station PLC system.

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