RU95122436A

RU95122436A - METHOD AND DEVICE FOR REGULATING A LIQUID METAL IN A CRYSTALIZER FOR INSTALLING CONTINUOUS METAL FILLING

Info

Publication number: RU95122436A
Application number: RU95122436/02A
Authority: RU
Inventors: Банни Тьерри; Друо Жоэль; Мартан Жан-Франсуа; Надиф Мишель; Беклер Дидье; Дюссе Эрве; Мушет Алан; Томардель Одиль
Original assignee: Соллак
Priority date: 1993-03-30
Filing date: 1994-03-17
Publication date: 1998-01-10

Claims

1. A method of controlling the level of the location of the meniscus of the liquid metal in the mold of a continuous metal casting plant, according to which electrical signals are emitted by at least one pair of sensors located directly above the meniscus, the electrical signals of these sensors being a function of the corresponding distances (h ₁ and h ₂ ) between the sensors and the meniscus, a combination of these two signals is carried out so as to obtain a single signal representing the conditional level of the menis ka, and the only signal thus obtained is fed to the control means of the device for controlling the flow of liquid metal entering the given mold, so that the control means actuates the control device so as to bring the conditional meniscus level to some predetermined value h, characterized in that that normalize each signal from the sensors, accompanied by the exclusion of oscillations having simultaneously a frequency exceeding a certain threshold value F, and amplitudes dy smaller some other threshold value D.

2. The method according to claim 1, characterized in that in the process of combining the above-mentioned signals generated by the sensors, the following operations are carried out: the value is calculated

and its absolute value or modulus

; the absolute value is compared

with two predefined diff _min and diff. _max provided that diff _min <diff _max ; if the value

diff _min , then the conditional meniscus level is taken equal to

if the value

≥ diff _max , then the fictitious or conditional level is taken equal to the value (Δh _max ), which is the largest absolute value of the values of h ₁ - h and h ₂ and h; if the ratio is observed

then the fictitious or conditional level takes equal

, where α is a parameter equal to

3. The method according to claim 1, characterized in that the signals generated by the said sensors are converted or digitized, and the normalization and combination operations are performed with the digital signals transformed in this way.

4. The method according to one of paragraphs. 1 to 3, characterized in that the threshold value F = 0.02 Hz.

5. The method according to one of paragraphs. 1 to 4, characterized in that the threshold value D = 3 mm

6. A device for controlling the level of the meniscus (13) of liquid metal in the mold (5) of the continuous casting metal installation, containing at least one pair of sensors located directly above the meniscus (13), each of these sensors (17, 18) giving a signal, which is representative with respect to the corresponding distance h ₁ and h _{2 of the} sensor from the meniscus (13), means (23) designed to combine these signals and produce a single signal that is representative of the relative level of the meniscus, in control means (24.15) of the device (14) for regulating the flow of liquid metal entering the mold, characterized in that the device also contains means (21, 22) for normalizing the sensor signals before combining them in such a way as to remove oscillations from these signals, having at the same time a frequency exceeding a certain threshold value F, and an amplitude below a certain threshold value D.

7. The device of claim 6, characterized in that it contains means (19, 20) intended for digitalization of signals issued by sensors (17, 18), as well as means (21, 22, 23) intended for normalization and combining said sensor signals are digital processing means.

8. The device according to claim 6 or 7, characterized in that the sensors (17, 18) are sensors that measure the Foucault currents.