DE1098971B - Device for vacuum degassing of molten metals, in particular steel - Google Patents

Description

It is known for the vacuum degassing of molten metals, in particular steel, to use the melt continuously by means of a gas from a container into a vacuum space above the level of the Melt is to be transferred, degassed there and then fed back into a container. The degassing space is here with the container in which the melt is located, through pipes tied together. During operation, the melt is carried up through one pipe and flows to the Degassing through another pipe back into the container.

This arrangement, which has proven itself very well, leaves something to be desired, however, as the Melt in the degassing space with large dimensions of the degassing space cools down and there slightly solidified. The degassing room could mostly only be uniform with considerable expenditure of heating energy are heated to the temperatures that avoid these disturbances, so that the in itself extraordinarily high advanced process was challenged by unfavorable conditions.

The present invention is based on the object of eliminating these disadvantages and the method to improve the continuous vacuum degassing to a large extent. A surprisingly simple one The solution to this problem was found in the degassing space above the melt small, and indeed to be made much smaller in volume than the volume of the molten metal to be degassed matters. It has been shown here that the vacuum degassing is then decisively improved can be if the volume of the degassing space is less than a fifth of the volume of the Container of the melt.

The particular advantage of the device for vacuum degassing of molten metals according to the invention is based on the fact that the degassing itself is in no way impaired by the much smaller degassing space, but that on the other Considerable technical advances have been made.

The degassing space, which is much smaller than in the known arrangements, becomes considerable warmed up faster and more evenly to the required temperatures. This guarantees that at the beginning of the degassing the melt, which is in a quickly and evenly heated degassing space occurs, is cooled only very insignificantly. It can therefore not partially solidify come and get stuck on the wall of the degassing space, as is the case with large degassing spaces could be observed frequently. This is also the case with the previously customary arrangements for vacuum degassing

molten metals,

especially steel

Applicant:

W. C. Heraeus

Company with limited liability,

Hanau / M., Heraeusstr. 12/14,
and Ruhrstahl Aktiengesellschaft, Witten

Dr. Albert Lorenz, Hanau / M.,
has been named as the inventor

Observed retention of material ("bears") is largely eliminated, so that after the degassing process has ended, the degassing space remains practically completely clean and without any residue of the degassed melt; because due to the faster and more uniform heating of the small degassing space, the radiation equilibrium is already reached at the first start of degassing, after 10 to 30 seconds, and this temperature is maintained until the end of degassing without significant cooling of the melt. The advantages of the proposal made are therefore manifold and contribute to a large extent to the operational reliability of the degassing process. Small degassing space, on the other hand, does not limit the amount of steel to be degassed. As an example, it should be mentioned that an amount of steel of around 801, i.e. around 10 m ³ volume, is degassed in 10 to 12 minutes by means of a degassing space of less than 1 m ^{s volume.} On the one hand, such a period of time is definitely available for degassing, but on the other hand it is surprisingly short in relation to the volume and the increase in quality of the degassed steel.

An embodiment of the device according to the invention is shown in section in the drawing. In the container 1 is the melt, which via the supply line 3 by means of a supplied gas in the small devel- opment in relation to the melt container

109 509/402

gassing chamber 2 and passed back into the container 1 via the discharge line 4 after degassing will.

It is quite surprising that a small degassing space according to the invention is sufficient, although one supplied gas is used as a conveyor. The gas bubbles formed during the introduction tear the liquid Metal when ascending into the evacuated degassing chamber 2, burst there and affect the The pressure prevailing there, which is chosen to be quite low for extensive degassing. That makes a difference the device according to the invention also from an already known one in which the metal is in its container is under vacuum and circulated by an additional electromagnetic device will.

Claims (1)

Claim: Device for vacuum degassing of molten metals, especially steel, in which the Melt continuously by an introduced gas from a container in a special, higher promoted than the melt level lying degassing space and after the degassing on another Way is guided back into a container, characterized in that the volume of the degassing space (2) is less than one fifth of the volume of the melt container (1). Considered publications:
British Patent Nos. 312 063, 339 579;
U.S. Patent No. 1,921,060. 1 sheet of drawings © 109 509/402 1.61