Method and device for the continuous detection of the slag level in electroslag remelting installations with short slidable molds

Abstract

A method and an installation for the continuous checking and regulation of the level of the surface of a slag bath in an ESR installation with short slidable molds. For the continuous measurement of the position of the surface of the slag bath, the method employs a radar beam emitted by a radar measuring probe and directed approximately vertically onto the surface.

1 . A method for electroslag remelting in a short slidable mold, wherein a level of a surface of a slag bath in an electroslag remelting installation is monitored, the method comprising the steps of:
 measuring the level of the surface of the slag bath with a radar measuring probe; directing a radar beam generated by the radar measuring probe so that the beam strikes the surface of the slag bath; and at least one of displaying the ascertained level of the surface by way of an evaluation device and using the ascertained level as an input signal for a control device for an ingot withdrawal from the slidable mold, so that the level of the surface of the slag bath is either kept constant or fluctuates periodically in a targeted manner within specific limits during the operation of the electroslag remelting installation.   
     
     
         2 . The method according to  claim 1 , wherein the radar measuring probe is disposed in a mold cover or a protective gas hood of the remelting installation. 
     
     
         3 . The method according to  claim 1 , including continuously measuring the level of the surface of the slag bath. 
     
     
         4 . The method according to  claim 1 , wherein the radar beam strikes the surface of the slag bath substantially vertically. 
     
     
         5 . The method according to  claim 1 , further including triggering an alarm in the event of abrupt, distinct changes in the level of the surface of the slag bath or when specific established limits of the level of the surface of the slag bath are exceeded or fallen below. 
     
     
         6 . An electroslag remelting installation for carrying out the method according to  claim 1 , comprising:
 a mold cover or a protective gas hood for covering a slag bath; and a radar measuring probe disposed on the mold cover or the protective gas hood for detecting a level of a surface of the slag bath, the probe generating a radar beam that strikes the surface of the slag bath.   
     
     
         7 . The electroslag remelting installation according to  claim 6 , and further comprising a measuring tube attached to the radar measuring probe so as to deflect the radar beam so that the radar beam strikes the surface of the slag bath substantially vertically. 
     
     
         8 . The electroslag remelting installation according to  claim 6 , and further comprising an evaluation device that displays or represents the level of the surface of the slag bath. 
     
     
         9 . The electroslag remelting installation according to  claim 6 , and further comprising a control device arranged to receive a signal from the radar measuring probe, the control device being operative to use the signal as an input signal for ingot withdrawal from the slidable mold. 
     
     
         10 . The electroslag remelting installation according to  claim 9 , and further comprising an alarm device in communication with the control device, wherein the control device is operative to activate the alarm device in the event of abrupt and distinct changes in the level of the surface or in the event of specific preset limits of the level of the surface are exceeded or fallen below.