Molten metal surface level detection system

• US 4,202,398 A
• Filed: 11/13/1978
• Issued: 05/13/1980
• Est. Priority Date: 11/13/1978
• Status: Expired due to Term

• Current Assignee: Furukawa Metals Company Limited
• Original Assignee: Furukawa Metals Company Limited
• Inventors: Osugi, Kozo
• Primary Examiner(s): Baldwin, Robert D.
• Assistant Examiner(s): Lin, K. Y.
• Application Number:
  US05/959,643
• Time in Patent Office: 547 Days
• Field of Search: 164/4, 164/150, 164/154, 164/449, 164/155, 358/100, 73/293
• US Class Current: 164/151.3
• CPC Class Codes: B22D 11/185 by using optical means

Abstract

In a molten metal surface level detection system, the use of conventional detector means is eliminated and, instead, an ITV camera is provided at an appropriate place where it is neither thermally affected by the molten metal surface portion nor obstructs the site jobs and the molten metal surface portion is photographed by said ITV camera along a direction permitting the surveillance of the level of the molten metal surface and, then, the thus photographed image of the molten metal surface portion is processed in a suitable manner for accurately and reliably detecting the surface level thereof.

Claims

1. An apparatus for detecting the level of poured molten metal in the liquid phase to eliminate false signals caused by flames and other signal-noise producing factors, comprising in combintion:

(a) an ITV camera which can be placed at some distance from the liquid level to be detected so as to photograph the level of said liquid metal surface including signal circuit means (13) for supplying an input signal;

(b) a reference frequency oscillator with first and second output sides;

(c) a signal generator (18) coupled to said first side of the reference frequency oscillator (17), said signal generator (18) being connected to the camera (12) for generating horizontal and vertical synchronizing signals (19) supplied to said camera (12);

(d) an image screen (16'"'"') connected to a picture element divider circuit (20), said picture element divider circuit (20) being coupled to said second output side, and serving to divide said screen (16'"'"') into a plurality of rectangular picture elements each being a defined zone along a first and a second axis normal to each other, said screen (16'"'"') having an input end receiving said input signal (13) from said signal circuit means;

(e) an amplifier clamping circuit (27) connected to said input signal end (13), a comparator circuit (28) including reference supply means connected to said clamping circuit (27), a discriminator (29) for supplying gate pulses connected to said comparator circuit (28) so that a gate pulse is supplied each time that an element correction to the aforementioned picture elements is scanned so that a plurality of scanning elements are sampled and the level of each element is compared with a reference provided by said reference supply means to provide an output either less than said reference or equal or more than said reference;

(f) a memory (30) connected to said discriminator (29) to temporarily store the output of the discriminator (29);

(g) a dynamic controller (31) coupled to said memory (30) said dynamic controller (31) generating and providing a sampling pulse to the memory (30) so that the output of the discriminator (29) is fed only at predetermined time periods to said memory (30); and

,

(h) an output level control circuit (32) connected to said memory for controlling the level of the molten liquid when the number of scanned elements having a value equal to or more than said reference exceeds a predetermined number so as to eliminate random signals caused by flame and other noise making materials causing only a random output equal or greater than said reference.