CN2581953Y - Detector for mould liquid level - Google Patents
Detector for mould liquid level Download PDFInfo
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- CN2581953Y CN2581953Y CN 02266583 CN02266583U CN2581953Y CN 2581953 Y CN2581953 Y CN 2581953Y CN 02266583 CN02266583 CN 02266583 CN 02266583 U CN02266583 U CN 02266583U CN 2581953 Y CN2581953 Y CN 2581953Y
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- liquid level
- crystallizer
- circuit
- data acquisition
- coil
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Abstract
The utility model relates to a level detector for a crystallizer. The periphery the crystallizer is provided with a group of coils connected with an alternating current power supply. The utility model is characterized in that the utility model also comprises a data acquisition system, a data processing system, a control system and an actuating mechanism which are orderly and electrically connected, wherein, the data acquisition system is connected with the coils; the actuating mechanism is mechanically and electrically connected to a slide plate on a water gap above the crystallizer. The utility model can realize the correct level detection of the crystallizer and the automatic control during the process of electromagnetic continuous casting production of soft contact; consequently, the electromagnetic continuous casting production process of the soft contact can be stabilized, and higher detection precision can be obtained.
Description
Technical field
The utility model relates to a kind of liquid level detection device, specifically, relates to the pick-up unit of molten steel in mold liquid level in a kind of soft-contact electromagnetic continuous casting process.
Background technology
The Detection ﹠ Controling of mould liquid level are one of gordian techniquies of casting process control, and it plays an important role for improving slab quality and steady production process.Liquid level is controlled bad or meniscus fluctuateed, and big city makes crystallizer protecting residue and impurity be involved in molten steel in a large number, not only has a strong impact on the output and the quality of strand, even can cause excessive steel and bleed-out accident in the casting cycle.Therefore, the accurate control of molten steel in mold liquid level is the important step that stabilizing continuous casting is produced.
In modern continuous casting production process, molten steel liquid level is the essential condition that stabilizing continuous casting is produced in the stable crystalline device, and the present method that has come into operation or succeeded in developing mainly contains: float method, emitting isotope method, electromagnetic eddy method and laser method etc.
The float method has two kinds, the one, the float made from fire resistive material places in the crystallizer, be suspended in the molten steel surface, by the buoyancy of molten steel and deadweight lifting and drive the leverage that is connected on the float and promote to control liquid level with liquid fluctuating, though it is simple in structure, be not subject to extraneous magnetic interference, but measuring accuracy is not high, has been not suitable for the requirement of modern continuous cast mold High Accuracy Control; Another kind is to establish electromagnetic sensor in the float made from fire resistive material in placing crystallizer, and when fluctuation took place liquid level, electromagnetic sensor produced signal, driving topworks's implementation liquid level controls automatically, but in this device, electromagnetic sensor is subject to the interference of surrounding magnetic field, and influences measuring accuracy.
The emitting isotope method mainly is that Co60 gamma-ray stream and transmitted intensity detecting device are installed on relative copper plate of crystallizer, the gamma-rays that utilizes ray stream to send is partially absorbed when passing molten steel, the detected gamma intensity of detecting device changes to be judged and controls liquid level, though this method precision is than higher, but, exist radiological protection and problems such as waste disposal and environmental protection owing to being measuring media with the radioelement.
Laser method is that generating laser visible emitting bundle is to the covering slag surface; form bright spot; absorb the image of this bright spot with image sensor, the variation of surperficial bright spot position is converted to and the proportional signal of mold liquid level, realize automatic control by gear train again liquid level in the crystallizer.
The electromagnetic eddy method is a kind of method relatively more commonly used at present, is made up of two groups of coils, is suspended in the crystallizer top.When applying the HF voltage (driving source of certain frequency for first group of coil, about 50kHz, power is about 0.1～1kW) time, produce the electromagnetic field of a sensing crystallizer, the nearly superficial layer of molten steel in the crystallizer induces vortex flow, vortex flow produces second magnetic field thus, in second group of coil (magnetic test coil), produce induced electromotive force again (owing to the HF voltage that applies in first group of coil is changeless, influence to second group of coil also just is a constant, can be revised by multiple authentication), its size depends on vortex flow, and the size of vortex flow depends on the actual distance of first group of coil with liquid steel level.Therefore, the induced electromotive force of second group of coil also depends on this distance, so, can record molten steel liquid level according to the size of the induced voltage of second group of coil, and signal is passed to action actuating mechanism, carry out the automatic control of molten steel liquid level.This method measuring accuracy height also be crystallizer liquid level control system technology relatively more commonly used in the present casting process, but this technology must guarantee not have outside crystallizer under other prerequisite that adds AC magnetic field, can correctly detect and control liquid level.
Soft-contact electromagnetic continuous casting is in recent years in order to improve surface quality of continuously cast slab, realizes continuous casting-tandem rolling abbreviated system and a new technology developing.So-called soft contact is that the split body continuous cast mold is applied high frequency magnetic field (frequency: 50-100kHz; Power: more than the 100kW); produce an electromagnetic pressure that points to strand inside in the initial solidification district; this electromagnetic pressure partial offset the static pressure of molten steel; make motlten metal meniscus projection; be contactless state between the motlten metal at meniscus place and the crystallizer, the covering slag flow channel broadens, the even Channel Group of covering slag; thereby alleviated owing to mold oscillation, covering slag flows into, flows out the dynamic pressure variation that is caused and the casting billet surface oscillation mark that causes.Through a large amount of simulated experiments, verified under the effect of high frequency magnetic field, continuous casting billet surface oscillation mark alleviates, and surface quality is improved.
Though the soft-contact electromagnetic continuous casting crystallizer has entered the commerical test stage at present, Level Detection and control are difficult points always.Above-mentioned float method has been not suitable for the requirement of modern continuous cast mold High Accuracy Control because measuring accuracy is not high.And the emitting isotope method also is difficult to apply in view of problems such as the protection in manipulating, waste disposal and environmental protection.Detect though laser method is applied at present test, invest higherly, required installing space is big; On the other hand, if covering slag changes greatly, be the top of the slag owing to what measure, have certain difference with true liquid level, measuring accuracy is difficult to control.
The magnetic float method is added precision problem own owing to can be subjected to the high power high-intensity magnetic field interference that inductive coil produces in the soft-contact electromagnetic continuous casting crystallizer, has been difficult to correctly detect and apply; Still, there is magnetic field in the changes of magnetic field that the liquid level eddy current is produced for the outside, during particularly with high power magnetic field, can be subjected to serious interference, precise decreasing, even be difficult to use.In order to overcome these difficult points, China Intellectual Property Office once disclosed a continuous casting electromagnetic metal liquid level pick-up unit patent (number of patent application that is used for aluminium continuous casting electromagnetic (no crystallizer) field; 91217006.9), its principle is that a magnetic test coil is set above inductor, in electromagnetic casting process, utilizes the variation of the induced potential that the eddy current of liquid aluminum produces to control metal liquid level.The difference of this method and eddy-current method is directly to have utilized electromagnetic casting to detect with magnetic field, and revises the influence of inductor current variation to the magnetic test coil induced potential by aided detection method is set, thereby improves accuracy of detection.But soft-contact electromagnetic continuous casting for steel, because the eddy current in the crystallizer split body is to the interference of magnetic test coil induced potential, the casting speed that adds steel is fast, and power greatly and often with factors such as batch (-type) frequency outputs, this method also is difficult to be applied to the soft-contact electromagnetic continuous casting of steel.
Summary of the invention
The purpose of this utility model provides a kind of mould liquid level pick-up unit, and it can realize the correct detection of mould liquid level in the soft-contact electromagnetic continuous casting production run and control automatically, thereby stablizes the soft-contact electromagnetic continuous casting production technology, reaches the higher detection precision.
The technical scheme that the utility model provides is, the mould liquid level pick-up unit is provided, one group of coil is set around crystallizer, this coil and an AC power are joined, and characteristics are, also comprise the data acquisition system (DAS) that connects of circuit in turn, data handling system, control system and topworks, described data acquisition system (DAS) and described coil join, the described topworks of the Skateboard exercising apparatus at the mouth of a river, described crystallizer top-be electrically connected.
Described data acquisition system (DAS) comprises the signal input circuit that becomes circuit to connect successively, signal is amplified and control circuit, frequency tester, the display circuit as a result of demonstration output signal, the output circuit of shaping;
Described data handling system is a logic comparison and a subtractor circuit, establish a preset value in this data handling system, this data handling system receives the signal of described data acquisition system (DAS), and compares with this preset value, do and ask difference to calculate, and produce a comparative result;
Said control system is used to receive the comparative result of described data handling system, and controls described topworks according to this comparative result;
The slide plate aperture at the described topworks described mouth of a river of may command, and then the liquid level of regulating described crystallizer.
The utility model, owing to utilized supply frequency signal data acquisition system and data handling system, can be continuously, the liquid level of molten steel in the crystallization control device quickly and accurately, and simplified measurement mechanism, both reduced cost and installation difficulty, can obtain higher liquid level control accuracy again, guarantee the quality of strand, improve the throughput rate and the economic benefit of operating conditions and raising casting machine.Mould liquid level pick-up unit of the present utility model is to realize key equipment technology safe, efficient, the robotization of zero defect continuous casting equipment.The utility model is simple in structure, effect is obvious, is applicable to soft-contact electromagnetic continuous casting crystallizers such as round base, square billet, slab.
Description of drawings
Fig. 1 is a structural representation of the present utility model.
Fig. 2 is a topworks of the present utility model structural representation.
Embodiment
Following according to Fig. 1, Fig. 2, a better embodiment of the present utility model is described.
As shown in Figure 1, one group of coil 2 is set around crystallizer 3, above this crystallizer, be the mouth of a river 9 and tundish 8, a described coil 2 and an AC power 1 are joined, and a data acquisition system (DAS) 4 that becomes circuit to connect is successively arranged, data handling system 5, control system 6, topworks 7, data acquisition system (DAS) 4 becomes circuit to be connected with coil; As shown in Figure 2, topworks 7 comprises a position transducer and a hydraulic pressure (or motor) driver, and it is arranged at the slide plate 91 at 9 places, the mouth of a river and the aperture of scalable slide plate with machine-electric connection mode.
Because the inductance L in the inductive coil outside the crystallizer changes with the variation of molten steel in mold liquid level h, it is big that h becomes, and then L also becomes big; H diminishes, and then L also diminishes.The power supply resonant frequency equation can be represented by the formula:
If it is big that f becomes, then L diminishes, and draws h and diminishes; Otherwise also set up.
Require benchmark molten steel liquid level height in the crystallizer is made as h according to continuous casting process
0, corresponding inductive coil inductance and power supply resonance frequency are made as L respectively
0, f
0, and with this preset value f
0Be stored in the data handling system 5, according to (1) Shi Kede,
If f＞f
0, L＜L then
0, draw h＜h
0, promptly liquid level is lower than reference value, can suitably increase liquid level;
Otherwise, if f＜f
0, L＞L then
0, draw h＞h
0, promptly liquid level is higher than reference value, can suitably reduce liquid level, wherein:
L
0: h
0Corresponding inductive coil inductance
f
0: h
0Corresponding power supply resonance frequency is as the data handling system preset value
L: inductive coil inductance
H: the molten steel liquid level height of actual measurement
F: the power supply resonance frequency of actual measurement
C: electric capacity
Data acquisition system (DAS) 4 is mainly by input circuit, control circuit, frequency tester, display circuit, output circuit are formed as a result, accept measured signal by input circuit, control circuit amplifies and shaping it, detect by frequency tester again, send the result to display circuit and output circuit; Data handling system 5 is a logic comparison and subtractor circuit, and it receives the signal f of data acquisition system (DAS) 4 outputs
0, and with its in the preset value f that establishes
0, draw a comparative result by comparing and asking poor, and send the result to control system 6; Control system 6 is sent corresponding execution command and is given topworks 7, complete operation.
Power supply resonance frequency f when the liquid level that collects molten steel in mold 10 when data acquisition system (DAS) 4 is h after showing and sending data handling system 5 to, carries out data processing by data handling system 5.Here data handling system 5 will be followed f from the f that data acquisition system (DAS) 4 transmits
0Carry out (preset value) relatively, obtain h＞h
0Or h＜h
0, f is followed f
0Difference (f-f
0) input control system 6,6 pairs of signals from data handling system 5 of control system carry out the control corresponding operation, and indicate topworks 7 to carry out the slide plate aperture adjustment work at the mouth of a river 9, finish the adjustment of molten steel 10 liquid level h in the crystallizer 3.Promptly as f＞f
0The time, h＜h
0, can increase the slide plate aperture, with this liquid level is increased; As f＜f
0The time, h＞h
0, can reduce the slide plate aperture, liquid level is descended; Adjusted liquid level h shows by data acquisition system (DAS) 4 again, data handling system 5, control system 6, topworks 7 carry out sequence of operations thus again, so going round and beginning again forms a closed loop, constantly adjusts, and h remains on optimum condition with liquid level.Its control accuracy and response speed depend primarily on the performance of frequency tester, logic comparison and subtractor circuit and control system 6.
Claims (3)
1. a mould liquid level pick-up unit is included in the one group of coil that is provided with around the crystallizer, and this coil and an AC power are joined; The crystallizer top is the water delivering orifice of tundish, establishes a slide plate on the water delivering orifice; It is characterized in that also having the data acquisition system (DAS) that connects with circuit in turn, data handling system, control system and topworks, described data acquisition system (DAS) and described coil join, the described topworks of described Skateboard exercising apparatus-be electrically connected.
2. mould liquid level pick-up unit as claimed in claim 1, it is characterized in that described data acquisition system (DAS) comprises the signal input circuit that becomes circuit to connect successively, signal is amplified and control circuit, frequency tester, the display circuit as a result of demonstration output signal, the output circuit of shaping.
3. mould liquid level pick-up unit as claimed in claim 1 is characterized in that, described data handling system is a logic comparison and a subtractor circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02266583 CN2581953Y (en) | 2002-08-26 | 2002-08-26 | Detector for mould liquid level |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02266583 CN2581953Y (en) | 2002-08-26 | 2002-08-26 | Detector for mould liquid level |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2581953Y true CN2581953Y (en) | 2003-10-22 |
Family
ID=33732362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02266583 Expired - Lifetime CN2581953Y (en) | 2002-08-26 | 2002-08-26 | Detector for mould liquid level |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2581953Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103048242A (en) * | 2013-01-21 | 2013-04-17 | 中冶赛迪电气技术有限公司 | Method and device for detecting solid fraction and final stage of solidification of continuously cast slab |
| CN104950929A (en) * | 2011-12-13 | 2015-09-30 | 江西稀有稀土金属钨业集团有限公司 | Vision-based automatic cast wheel liquid level control system and vision-based automatic cast wheel liquid level control method |
| CN105665675A (en) * | 2016-04-07 | 2016-06-15 | 江苏永钢集团有限公司 | Automatic control and alarming system of molten steel liquid level in crystallizer of continuous casting machine |
-
2002
- 2002-08-26 CN CN 02266583 patent/CN2581953Y/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104950929A (en) * | 2011-12-13 | 2015-09-30 | 江西稀有稀土金属钨业集团有限公司 | Vision-based automatic cast wheel liquid level control system and vision-based automatic cast wheel liquid level control method |
| CN103048242A (en) * | 2013-01-21 | 2013-04-17 | 中冶赛迪电气技术有限公司 | Method and device for detecting solid fraction and final stage of solidification of continuously cast slab |
| CN105665675A (en) * | 2016-04-07 | 2016-06-15 | 江苏永钢集团有限公司 | Automatic control and alarming system of molten steel liquid level in crystallizer of continuous casting machine |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CX01 | Expiry of patent term |
Expiration termination date: 20120826 Granted publication date: 20031022 |