EP3992310A1 - Method and device for the pouring of metal melt from a metallurgical container - Google Patents

Abstract

The present invention relates to the field of metallurgical plants, specifically metallurgical vessels for molten metal and liquid slag /or liquid metal comes over the top opening of the metallurgical vessel.The task is solved in that the tilt angle (ϕ) is determined by a function or a look-up table. As an input variable for determining the tilting angle (φ), the function has at least a weight of that melt which is currently in the metallurgical vessel (5). The tilting angle (φ) is displayed to an operator or transferred to a control and/or regulating device of a tilting drive (3).

Description

field of technology

The present invention relates to the field of metallurgical plants, specifically metallurgical vessels for molten metal and liquid slag.
On the one hand, the invention relates to a method for determining a tilting angle during a pouring process of molten metal, in particular molten steel, from a metallurgical vessel that can be rotated about an axis of rotation, in particular a converter, through a tap opening of the metallurgical vessel into a metallurgical target vessel, in particular a ladle.

On the other hand, the invention relates to a device for pouring molten metal, in particular molten steel, from a metallurgical vessel. The metallurgical vessel is rotated with a tilting drive in order to pour the molten metal through a tap opening having the metallurgical vessel.
Furthermore, the invention relates to a computer program for executing the method and a computer-readable medium for storing the computer program.

State of the art

In the production of liquid metal melts - for example in a steelworks - converters are used to produce steel. After a batch has been completed and an iron or nickel dominated premelt has been reduced to steel along with scrap, the molten metal is tapped into a ladle beneath the converter. In order for the steel to flow out of a tap hole, the converter must be rotated. The tapping is current often performed manually, which means that operators in the tapping control room rotate the converter manually using a joystick. Tapping is carried out with constant observation of the converter outflow and ladle. The converter itself as well as a converter lining and the tap hole are subject to slow but constant wear.

This leads to slowly changing geometrical properties, making tapping a new challenge for the operator each time. The operating personnel must therefore monitor several sources of danger at the same time in order to ensure smooth tapping. The disadvantage here is that these operating personnel have to be extensively trained and continuously trained, which makes the automation of this tapping increasingly attractive for plant operators.

Tapping is currently mainly carried out manually. The automation system positions a ladle car with the ladle under the converter. During tapping, the operating personnel manually controls the inclination of the converter by looking at the converter and ladle truck through a viewing window.

If the tapping is carried out automatically, the flow at the tap hole - volume flow from the converter into the ladle - is measured as a possible solution. With the help of a controller, the converter angle is regulated in such a way that the same volume flow always flows into the ladle.

It is particularly critical here that the tap hole is subject to wear and tear, and the outflow thus varies constantly. If there is also caking in the area of the tap hole, this leads to a reduced outflow and thus to a smaller tapping stream. If, in such a case, the tilting angle of the converter is further increased, an unintentional pouring out via an upper opening of the converter - the so-called converter mouth - can occur.

This can lead to a significant safety risk but also damage to the ladle vehicle.

Summary of the Invention

The object of the invention is to provide a simple method which determines a permissible tilting angle of the metallurgical vessel at which there is no outflow of slag and/or liquid metal via the upper opening of the metallurgical vessel.

The task is solved in that the tilt angle is determined by a function or a look-up table, which has at least one weight of the melt m _rest , which is currently in the metallurgical vessel, as an input variable for determining the tilt angle ϕ _converter - as in Equation 1 shown. $${\mathrm{\phi }}_{\mathit{converter}}=f\left(m_{\mathit{rest}}\right)$$

The tilting angle is then displayed to an operator or transferred to a control and/or regulating device of the tilting drive. The operator can set the tilt angle according to the specification, which is displayed on a screen, for example. If the tapping of the converter takes place automatically, the default value is transferred to a corresponding control and/or regulating device of the tilting drive and the default is only determined as a function of the residual weight that is in the converter. A determination of the converter angle independently of time is decisive for this invention. The decisive variable is only the weight of the remaining amount of the melt in the metallurgical vessel. The method described ensures that no unintentional pouring over the upper opening of the metallurgical vessel - the so-called converter mouth - occurs during the pouring process during automatic tapping. The upper metallurgical opening is used, for example, for filling the liquid metal and scrap into the metallurgical vessel. In the case of a tapping performed by the operator, this may change on Orientate the specified tilting angle to avoid an unwanted overpouring over the converter mouth. This process ensures optimized operation of the converter during tapping, regardless of caking around or inside the tap opening. In the look-up table - so-called look-up tables - a tilting angle is entered depending on the residual weight of liquid melt. The differences between the individual residual weight entries can be selected as desired. This depends, among other things, on the size of the metallurgical vessel. It is also conceivable to interpolate between the individual residual weight entries. Execution using lookup tables has the advantage that an easy implementation in industrial control systems is possible.

A preferred embodiment provides that a further input variable is a number of pouring processes that have already taken place. A brick lining located in the converter is also subject to wear, which leads to a change in the geometry within the converter. This change leads to a change in the tilt angle. This wear can be quantified by a number of melts produced. The melts produced can be recorded by the number of pouring processes n _tap - as shown in Equation 2. $${\mathrm{\phi }}_{\mathit{converter}}=f\left(m_{\mathit{rest}},n_{\mathit{racking}}\right)$$

It has been shown that in many cases an adjustment of the function or the look-up table for the tilting angle after a predefined number of pouring processes, for example 500, ensures an optimized and reliable pouring process.

An expedient embodiment provides that the function is a polynomial with at least the third order, a logarithmic function, an exponential function or their combinations is. The functions used are selected in such a way that theoretical or applied casting processes are simulated congruently.

Brief description of the drawings

1 and 2 show a schematic representation of a tapping process.

Description of the embodiments

In 1 a metallurgical vessel 5 is shown with a lining 5a. Molten metal 8 and liquid slag 7 are contained in this metallurgical vessel 5 . The liquid metal 8 is poured out through a tap opening 9 . The pouring stream 10 emerges from the tap opening 9 and is poured into a metallurgical target vessel 11 . The tilting angle is determined by a computer unit 1 on the basis of the weight of the residual amount of melt currently in the metallurgical vessel. An example of determining the tilt angle is shown in Equation 3. $${\mathrm{\phi }}_{\mathit{converter}}=a_6\ast m_{\mathit{<figure-callout\; id="6"\; label="rest"\; filenames="imgf0001.png"\; state="\{\{state\}\}">rest</figure-callout>}}^6+a_5\ast m_{\mathit{<figure-callout\; id="5"\; label="rest"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">rest</figure-callout>}}^5+a_4\ast m_{\mathit{rest}}^4+a_3\ast m_{\mathit{<figure-callout\; id="3"\; label="rest"\; filenames="imgf0002.png"\; state="\{\{state\}\}">rest</figure-callout>}}^3+a_2\ast m_{\mathit{<figure-callout\; id="2"\; label="rest"\; filenames="imgf0001.png"\; state="\{\{state\}\}">rest</figure-callout>}}^2+a_1{m}_{\mathit{rest}}$$

This result is either transmitted directly to a tilting drive (not shown) by the computer unit 1 or it is displayed to the operator of the system on a display unit 2--for example a screen. The weight of the remainder is determined, for example, by considering the weight of materials supplied when loading the metallurgical vessel and molten metal removed. The discharged molten metal is determined by weighing the target vessel 11 during the pouring process. However, it is also conceivable to determine the weight based on the fill level with a known target vessel geometry. There are also other direct or indirect methods that Determination of the weight of the residual amount of melt in the metallurgical vessel, conceivable.

In 2 the tilting drive 3 is shown, with which the metallurgical vessel is tilted by an angle φ. In this embodiment variant, the pouring process is controlled or regulated directly by the computer unit—using the method described. The tilting drive 3 receives corresponding control or regulation signals from the computer unit 1 . A weight of the molten metal already discharged from the metallurgical vessel 5 is transmitted to the computer unit 1 by a weighing unit 13 , which is located on a ladle car 12 . The computer unit 1 is also sent information from a memory 1a about the charge materials supplied to the metallurgical vessel 5 . From this, the computer unit 1 can determine the weight of melt that is currently in the metallurgical vessel.

Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Reference List

1

computing unit

1a

Storage

2

display unit

3

tilt drive

5

metallurgical vessel

7

liquid slag

8th

molten metal

9

tapping hole

10

pouring stream

11

target vessel

12

pan wagon

13

weighing unit

ϕ

tilt angle

Claims (6)

Method for determining a tilt angle (φ) during a pouring process of molten metal, in particular molten steel, from a metallurgical vessel (5) that can be rotated about an axis of rotation, in particular a converter, through a tap opening of the metallurgical vessel (5) into a metallurgical target vessel (11) , in particular a ladle, characterized in that the tilting angle (ϕ) is determined by a function or a look-up table, the function as an input variable for determining the tilting angle (ϕ) containing at least one weight of that melt which is currently in the metallurgical vessel (5th ) is located, with the tilting angle (φ) being displayed to an operator or being transferred to a control and/or regulating device of a tilting drive (3). Method for determining a tilt angle (ϕ) during a melt pouring process according to Claim 1, characterized in that a further input variable is a number of pouring processes that have already taken place. Method for determining a tilt angle (φ) during a melt pouring process according to Claim 1 or 2, characterized in that the function is a polynomial of at least third order, a logarithmic function, an exponential function or combinations thereof. Device for pouring molten metal (8), in particular molten steel, from a metallurgical vessel (5), the metallurgical vessel (5) being rotated with a tilting drive (3) in order to pour the molten metal (8) over a metallurgical vessel (5 ) pour having, tapping opening (9), thereby characterized in that a computer unit (1) carries out the method according to one of Claims 1-3. A computer program comprising instructions that cause the method of claims 1-3 to be carried out. A computer-readable medium storing the computer program of claim 5.

Images