SU232512A1 - TELEVISION METHOD OF MEASURING THE VOLUME OF MOLTEN METAL IN VESSEL - Google Patents

Description

The invention relates to methods for measuring volumes of molten metal in vessels, to dosing when pouring metal into molds, and can be applied in other areas of the measurement technique.

Various methods are known for measuring the volume of molten metal in a vessel, but all of them, to varying degrees, are contact ones, associated with many complications in the manufacture of appropriate apparatus. In addition, sensors that are sensitive to changes in temperature introduce errors in the measurement results that require additional devices to compensate for them.

The proposed method allows to increase the measurement accuracy.

For this, the optical axis of the television tube is directed to the middle of the surface of the molten metal, this surface is projected onto the photocathode of the television tube and, according to the duration of the pulses taken from it, the images of the projected surface of the molten metal are judged on its volume in the vessel.

FIG. 1 shows the location of the transmitting television tube relative to the vessel with molten metal; in fig. 2 is a block diagram of an apparatus for carrying out the foregoing method.

The volume of a parallelepiped-shaped vessel can be expressed by the equation

V K.y.z, (1)

where X, y, Z are the edges of the parallelepiped.

When L const, the const expression will take the form

V l (z). (2)

If the optical axis of the transmitting television tube is positioned at an angle to the surface of the molten metal on a smallpox O - O (Fig. 1), then we can assume that the visible part of the surface can be described by the equation

AC ozig, (3)

where oz is the height of the molten metal.

Since the optical axis of the transmitting tube is located at an angle a to the metal surface, only a projection of the visible part of the surface is projected onto its photocathode, called the “base”

LV LS.51pa. (4)

Substituting equation (3) into expression (4),

Substituting the value of oz AB in expression (2), we obtain a new relation

1 / f (LV). (6)

Therefore, the task of determining the volume of liquid metal or weight in a vessel can be reduced to determining the value of the linear size of the base AB with the help of a transmission television tube.

Ratio. (6) it is not difficult to calculate for any geometry of the vessel, which is necessary when drawing up a program introduced into the counting device. Angle and also choose depending on the geometry of the vessel.

The volume of molten metal in the vessel is determined as follows.

The optical axis of the television tube / (see Fig. 1), operating in single-line scanning mode together with the optic and optical filter, is centered on the surface 2 of the molten metal, projecting the surface onto the photocathode of the television tube and using the pulses from the image of the projection of this surface molten metal is judged on its volume in vessel 3.

The video signal of the image is fed to the block 4 {see. FIG. 2) electronic signal processing, which amplifies and forms a pulse, the duration of which is ir proportional to the value of the base AB.

Block 5 of the generator of calibration imulses contains a stable crystal oscillator and a shaper of square calibrated pulses. These pulses, simultaneously with imyv of the electronic processing unit, are iodine to pulse-type

scheme 6 matches. From this circuit, during the sweep period, the computing device 7 removes pulses, the sum of which is directly proportional to the value of the base AB. Device 7 also includes data on vessel geometry and molten metal parameters.

The computing device calculates the volume (weight) of the molten metal, taking into account the constant displacement caused by the presence of the meniscus, generates control pulses of the electronic scaling unit 8, as well as a signal to the digital indicator device 9 and the automation unit 10.

With a small base value, the surface of the tube photocathode is poorly used. A stepwise decrease in the span of the single-swept sawtooth pimuls allows one to increase the duration of the video pulse and, consequently, the measurement accuracy. Block

Electronic scale control controls the extraction device.

Subject invention

A television method for measuring the volume of molten metal in a vessel using a transmission television tube, operating in a single-line scan mode, characterized in that, in order to improve measurement accuracy, the optical axis of the television tube is directed to the middle of the surface of the molten metal, projecting this surface onto the photocathode of the television tube and by the duration of being removed from it

the pulses of the image of the projection of the specified surface of the molten metal are judged on its volume in the vessel.

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