GB2109940A - Method and apparatus for controlling the liquid metal level in a continuous casting mould - Google Patents
Method and apparatus for controlling the liquid metal level in a continuous casting mould Download PDFInfo
- Publication number
- GB2109940A GB2109940A GB08230944A GB8230944A GB2109940A GB 2109940 A GB2109940 A GB 2109940A GB 08230944 A GB08230944 A GB 08230944A GB 8230944 A GB8230944 A GB 8230944A GB 2109940 A GB2109940 A GB 2109940A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rods
- liquid metal
- melt
- continuous casting
- controlling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/18—Controlling or regulating processes or operations for pouring
- B22D11/181—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level
- B22D11/186—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level by using electric, magnetic, sonic or ultrasonic means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Continuous Casting (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Abstract
A method of controlling a liquid metal level in a continuous casting mould (1) employs a pair of electrically conducting rods (4) which dip into the melt (2) and the electrical resistance of which is variable in dependence upon the depth of the melt, the resistance being measured for example by bridge 6. The rods are formed of a material which is resistant to the melt and signals from the probe are applied to processing circuitry (7,8) for controlling a slide valve (5) which is used to open and close an output port of a tundish (10) acting as a reservoir for the mould. The rods may be of high resistivity and connected at their lower end to form a U configured probe. <IMAGE>
Description
SPECIFICATION
Method and apparatus for controlling the liquid metal level in a continuous casting mould
The invention relates to a method and apparatus for controlling the liquid metal level in a continuous casting mould.
Because of the special environmental conditions (heat, dust, covering agents, metal splashes etc), an apparatus for controlling the liquid metal level mounted on a casting unit, must itself be robust and simple, both constructionally and with regard to handling. Additionally, it is required that the apparatus can be employed for all types of mould, and for all sizes of mould, as well as in the case of every alloy which has to be cast.
A known apparatus and method is disclosed in
U.K. Patent Application No. 8039889 in which the level of the liquid metal surface is measured by an eddy-current technique utilising a loop located either above or in the melt. Using such a technique, it is necessary to use direct current.
The present invention seeks to provide a method and apparatus for controlling the liquid level in continuous casting moulds which is able to use either direct current or alternating current.
According to one aspect of this invention there is provided a method for controlling a liquid metal level in a continuous casting mould including the steps of detecting a change in the liquid metal level resulting from the change in the electrical resistance of two electrically conducting rods which dip into the melt but which are made of a material resistance to the melt and producing a measurement signal therefrom in a measuring system.
In a preferred embodiment of the invention, the change in resistance is measured by a direct-current resistant measuring bridge, or by an alternatingcurrent resistance measuring brdige, or is determined from a current/voltage measurement.
It is preferable to zero-balance the measuring system when the liquid metal surface is at the required level, and to use the measurement-signal, arising when the liquid metal surface departs from the required level, in order to effect control.
After further processing, the measurement-signal advantageously actuates, a stopper-valve or slidevalve in a tundish of the continuous casting mould.
According to a further aspect of this invention there is provided an apparatus for controlling a liquid metal level in a continuous casting mould including a probe formed by two electrically conducting rods which are arranged to dip into the melt in the continuous casting mould but which are made of a material resistant to the melt and a measurement system connected to the rods arranged to detect a change in the electrical resistance of said rods in dependence upon the level of melt in the mould.
The rods preferably possess a high resistivity, in order to measure as large a change in resistance as possible whenever a change in the liquid metal level occurs. These requirements are met, in particular, by rods manufactured from chromium-steel, graphite, or a cermet, it being possible for these rods, in addition, to be composed of material of any desired shape and size.
In one embodiment of the invention, the rods are connected, at the lower end, in a manner permitting conduction, so that the probe is designed in the shape of a "U". So as to hold the rods, and to reduce the resistance of the supply leads, it is convenient to fasten the rods to busbars, which may be manufactured from any desired, electrically conducting material such as copper, but if the intention is that the temperature-coefficient of the electrical resistance should be as low as possible, constantan or manganin may be used.
The invention will now be explained by way of example with reference to the accompanying drawings, in which:
Figure 1(a) shows a vertical cross-section of a mould with a probe in accordance with the invention;
Figure l fbJ shows a plan view of the mould shown in Figure 1(a); and
Figure 2 shows a block circuit diagram of the measuring and control system.
In the Figures, like reference numerals denote like parts.
Figures 1 and 2 represent, diagrammatically, a continuous casting mould 1, containing a melt 2 having a liquid metal surface 2', into which two rods 4 dip. The rods 4 form a probe and are manufactured from an electrically conducting material having high resistivity which is resistant to the melt 2. The length, shape and cross-sectional area of the rods 4 can be selected to suit the requirements of the mould and material being cast, but in one embodiment the rods are connected at their lower end to form a U-shape.
The rods may be chromium steel, graphite or cermet. Copper busbars 3 hold the rods 4, and help to reduce the resistance of the supply leads. The rods 4 are connected, by other busbars 3, to a self-balancing direct-current resistance measuring bridge 6, (or alternatively to a seif-balancing alternating-current resistance measuring bridge 6). Following start-up ofthe casting unit, the bridge 6 automa ticallyzero-balances as soon as the level of the liquid metal surface 2' has reached the required height.
A change in the liquid metal level produces a measurement signal at the output terminal of the bridge 6 which is amplified in an evaluating unit 7 and, if alternating current is being used, is demodulated and filtered. The measurement signal, thus further processed, passes to a controller 8 which, with the aid of a motor 9, actuates a stopper-valve or a slide-valve 5 and thereby regulates the feeding of the metal 2, from a tundish 10, into the continuous casting mould 1 to thereby maintain a required melt level.
Round graphite bars, having a diameter of 10 mm and a length of 150 mm, can, for example, be used as the rods 4, while copper busbars, having a rectangu larcross-section, 20 mm by 15 mm and a length of 90 cm, can be used as the current busbars 3.
The resistance of the copper busbars 3 is only 0.1 mQ, while, in contrast, that of the graphite rods 3 is 31 mQ the change in resistance, of 2 mQ per cm change in liquid metal level, being readily measurable by means of a commercially available resistance measuring bridge 6.
Claims (13)
1. A method for controlling a liquid metal level in a continuous casting mould includes the steps of detecting a change in the liquid metal level resulting from the change in the electrical resistance of two electrically conducting rods which dip into the melt but which are made of a material resistant to the melt and producing a measurement signal therefrom in a measuring system.
2. A method as claimed in Claim 1, wherein the change in resistance of the rods is measured by a direct-current resistance measuring bridge, or by an alternating-current resistant measuring bridge.
3. A method as claimed in Claim 1, wherein the change in resistance is determined from a currents voltage measurement.
4. A method as claimed in Claim 2 or 3, wherein the measuring system is zero-balanced when the liquid metal surface is at the required level and the measurement signal arising when the liquid metal surface departs from the required level is used to effect control.
5. A method as claimed in Claim 4, wherein after further processing, the measurement signal actuates a stopper-valve or a slide-valve in a tundish to thereby supply the mould.
6. An apparatus for controlling a liquid metal level in a continuous casting mould includes a probe formed by two electrically conducting rods which are arranged to dip into the melt in the continuous casting mould but which are made of a material resistant to the melt and a measurement system connected to the rods arranged to detect a change in the electrical resistance of said rods in dependence upon the level of melt in the mould.
7. An apparatus as claimed in Claim 6, wherein the rods possess a high resistivity.
8. An apparatus as claimed in Claim 6 or 7, wherein the rods are composed of chromium-steel, graphite, or a cermet.
9. An apparatus as claimed in any of Claims 6 to 8, wherein the rods are connected at their lower ends, in manner permitting conduction.
10. An apparatus as claimed in any of Claims 6 to 9, wherein the rods at their ends remote from the melt are fastened to busbars which are composed of electrically conducting material.
11. An apparatus as claimed in Claim 10, wherein the busbars are composed of copper, constantan, or manganin.
12. A method for controlling a liquid metal level in a continuous casting mould substantially as herein described with reference to and as illustrated in the accompanying drawings.
13. An apparatus for controlling a liquid metal level in a continuous casting mould substantially as herein described with reference to and as illustrated in the accompanying drawings.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19813146360 DE3146360C2 (en) | 1981-11-23 | 1981-11-23 | Device for level control of the bath level in a continuous casting mold |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2109940A true GB2109940A (en) | 1983-06-08 |
Family
ID=6146993
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08230944A Withdrawn GB2109940A (en) | 1981-11-23 | 1982-10-29 | Method and apparatus for controlling the liquid metal level in a continuous casting mould |
Country Status (3)
Country | Link |
---|---|
DE (1) | DE3146360C2 (en) |
FR (1) | FR2516822B1 (en) |
GB (1) | GB2109940A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0380774A2 (en) * | 1989-02-02 | 1990-08-08 | Krupp Stahl Aktiengesellschaft | Method of and installation for regulating a liquid metal level in the pouring basin of continuous casting plants for strips |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105057609B (en) * | 2015-09-22 | 2017-11-14 | 武汉钢铁有限公司 | The control method of Baogang's water level in continuous casting |
CN106670440B (en) * | 2016-12-30 | 2017-11-24 | 北京航空航天大学 | The traveling probe speed-measuring method and device of a kind of vacuum speed governing casting process |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1105568B (en) * | 1956-03-07 | 1961-04-27 | Ver Leichtmetallwerke Gmbh | Process for the automatic control of the metal supply during continuous casting of metals |
DE1184905B (en) * | 1962-04-19 | 1965-01-07 | Boehler & Co Ag Geb | Device for controlling the melt flow when pouring into a mold in continuous casting plants |
FR1463902A (en) * | 1965-10-05 | 1966-07-22 | Siderurgie Fse Inst Rech | Adjustment of a flow rate of liquid metal flowing through an orifice |
ES448358A1 (en) * | 1975-07-17 | 1977-07-16 | Gerdts Gustav F Kg | Probe for measuring liquid levels |
JPS5376926A (en) * | 1976-12-21 | 1978-07-07 | Nippon Kokan Kk | Molten metal level monitor controller of continuous casting machine that use eddy flow system range finder for measurement of molten metal level |
DE2747479C2 (en) * | 1977-10-22 | 1983-12-15 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Device for electrically measuring the height of electrically conductive liquids |
DE2951097C2 (en) * | 1979-12-19 | 1982-07-22 | Wieland-Werke Ag, 7900 Ulm | Method and device for controlling the mold level in continuous casting molds |
-
1981
- 1981-11-23 DE DE19813146360 patent/DE3146360C2/en not_active Expired
-
1982
- 1982-10-29 GB GB08230944A patent/GB2109940A/en not_active Withdrawn
- 1982-11-19 FR FR8219460A patent/FR2516822B1/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0380774A2 (en) * | 1989-02-02 | 1990-08-08 | Krupp Stahl Aktiengesellschaft | Method of and installation for regulating a liquid metal level in the pouring basin of continuous casting plants for strips |
EP0380774A3 (en) * | 1989-02-02 | 1992-01-29 | Krupp Stahl Aktiengesellschaft | Method of and installation for regulating a liquid metal level in the pouring basin of continuous casting plants for strips |
Also Published As
Publication number | Publication date |
---|---|
DE3146360C2 (en) | 1983-10-27 |
DE3146360A1 (en) | 1983-06-01 |
FR2516822B1 (en) | 1986-12-19 |
FR2516822A1 (en) | 1983-05-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |