DE102008008033A1 - Device for slag-free tapping or for transferring a melt - Google Patents

Abstract

The invention relates to a device for slag-free tapping or for transferring a melt from a metallurgical vessel (1, 2, 3) in another metallurgical vessel with a siphon-like, inverted U-shaped configuration, wherein the siphon (4) has an inlet channel (5). , a connecting channel (6) and an outlet channel (7), and the inlet channel (5) and the outlet channel (7) are plungable into the dispensing or the receiving vessel. Such a device should be created with good maintainability and high availability, while at the same time interrupting the operation of a worn tapping system should be avoided. To achieve this, the siphon (4) is designed as a separate, mobile unit.

Description

Facility for slag-free tapping or transfer a melt from a metallurgical vessel in another metallurgical vessel, in particular from a tiltable or fixed arc furnace, in siphon-like Training with the features specified in the preamble of claim 1.

In order to stave off slag-free, simple siphon punctures have been known for some time, but have largely been displaced by bottom taps for reasons of gas uptake of the melt during tapping and lower tilting requirements. In order to combine the advantages of both systems, siphon taps were designed which result in a bottom tapping ( DE 102 23 906 A1 ).

There, a bay is specially designed or designed a separately attached bay, which adjoins a connecting wall of the lower vessel of the arc furnace and is connected via a tapping channel with this. In the DE 102 23 906 A1 can be controlled at pressure and vacuum-tight cover of this bay window, by controlling the gas pressure in the bay, the tapping speed of the melt or the tapping can be started or interrupted.

Also from the EP 1 181 491 B1 a metallurgical vessel is known in which a siphon is an integral part of the lower part of the vessel.

To the transfer of melt from a fixed metallurgical vessel in a subsequent vessel for the next metallurgical process is funded by the University of Missouri Rolla a cascading arrangement of vessels executed, the solid siphon-like vessel structures have to be operated continuously.

at The listed concepts are accessibility the channels of the siphon for maintenance work difficult to realize. It can not be ruled out that Freezing or washout in the aforementioned systems to functional impairments and long stoppages. The integration of siphon systems (Missouri Rolla) affects the Metallurgically optimal design of the vessels between smelting unit and distributor. Generally, by the Integration of siphon systems in or on the metallurgical vessels The freedom of design for process-optimized design the metallurgical vessels restricted.

Of the Invention is therefore based on the object, a device of initially mentioned type for slag-free melt transfer with good maintainability and high availability, with the continued business interruption for the exchange avoid a worn tapping system. allows should also be the use of a fixed arc furnace.

These Task is inventively in a generic Device solved by the fact that the siphon as a separate, mobile unit is formed.

Of the The essence of the invention is thus that the siphon for slag-free Do not transfer the melt into the vessel Smelting or firmly integrated for metallurgical work is, therefore, not firmly attached to this construction, but as an independent, independently movable or movable system formed is.

Of the Melt flow can be introduced by means of a negative pressure in the channel and maintained and interrupted by releasing the negative pressure again become. To control the melt flow and the melt level in the field of refractory channel ends is, according to a preferred Embodiment suggested that at least one vessel in the height is movable. The proposal is intended to allow be that with the help of the siphon concept a slag-free tapping and / or a fixed arc furnace and generally a slag-free transfer of melt between metallurgical vessels reliable. Continue to be the concept especially in a relatively simple way of electric arc furnaces, Steel pans, etc. can be realized and in a simple way maintenance and in particular allow a quick replacement of the siphon. The system should also have controllability of the melt flow between the vessels, in particular Beginning and end of the melt flow.

The Invention will become more apparent hereinafter with reference to the drawings explained.

there the figures show schematically different variants of the invention Facility.

After 1 the transfer of a melt from an electric arc furnace takes place 1 into a first metallurgical vessel 2 and from there into a second metallurgical vessel 3 ,

The siphon is in this and in all other figures with 4 denotes and consists of an inlet channel 5 a connecting channel 6 and an exit channel 7 ,

In this case, a siphon 4 with refractory lined channels over the two vessels positioned so that the two ends of the inlet and outlet channel 5 . 7 protrude into the respective melt. Between the vessel to be emptied and the one to be filled 1 . 2 there is a difference in altitude. To initiate the melt flow is at the upper end of the outlet channel 7 built up a negative pressure. The corresponding connection is with 8th quantified. The melt flow is essentially due to the height difference between the melts in both vessels 1 . 2 and the channel cross-sections and can be varied to some extent by relative height change of the vessels.

The 2 shows the melt flow between two metallurgical vessels, in which the vessel to be filled is initially empty and is filled from the arc furnace.

To generate a negative pressure in the outlet channel 7 In order to initiate the melt flow between the vessels, the channel end is temporarily sealed gas-tight in the vessel to be filled. The closure 10 can be realized for example by sheets or plates at the channel end, which are provided with sealing compounds. Release of the melt flow can be achieved by actively removing or opening the closure 10 be realized by timely melting of the shutter or exceeding a threshold value of the metallostatic pressure on the closure. It should be noted that the possibly necessary residual evacuation of the melt channel takes place more quickly than the gas volume in the channel rises again by the start of the melt outlet.

In order to transfer the melt only a small part of the outlet channel 7 immersed in the melt, the vessel to be filled is movable in height and is lowered during the tapping process according to the melt flow steadily down. In principle, the outlet end of the melt or outlet channel 7 but also outside the melt of the vessel to be filled.

To the degree of filling of the melt channel 7 to capture (as in 3 shown), for example, on a channel 11 at the upper end of the connection channel 6 , which is also used for evacuation, by means of a sensor 15 recorded the level of the melt in the channel system. The recorded ride height can be from a control unit 12 be linked to the vacuum generation.

In support of the melt flow in the channel can in the inlet channel 5 the melt, similar to an RH plant, inert gas 13 be introduced ( 3 ). This accelerates the flow rate and increases the metallurgical purity.

To detect running slag can after 4 preferably in the inlet channel 5 a slag detection system 14 be installed (for example, an induction coil around the channel). In the case of slag detection, the slag transfer can be reduced or avoided to a minimum by rapid gas filling of the melt channel. With conventional slag detection on the EAF, efficient intervention is significantly less favorable.

A Another possibility for detecting trailing slag when emptying a vessel is the detection the course of the negative pressure in the evacuation channel. Becomes slag sucked in, this shows in a discontinuity of the pressure curve.

To the Preheating the melt channel in unsteady use, the channel be preheated with hot burner gases or for example be brought into a preheating furnace.

In order to minimize the temperature drop of the melt during the transfer of the melt or to introduce additional heat into the melt, can around the melt channel, such as the connecting channel 6 , around an induction heating 9 be installed, which can be carried out very effectively due to the constant channel cross-section.

The ends of the channels 5 . 7 which dip into the melts, should preferably be carried out quickly interchangeable, as can form over time slag approaches and the edges of the inlet opening are subject to wear.

at an adapted embodiment of the above-described Tapping this can also for the slagging, z. B. a fixed arc furnace used. To recognize the For example, boundary layer between slag and melt can the tapping system are subjected to a gas pressure, wherein on reaching the boundary layer the gas pressure due to the higher Density of the melt increases. When addressing this signal can then the system slightly withdrawn, the Vacuum for the suction of the slag generated and thus to detoxify the vessel.

The advantages that can be achieved with the device according to the invention can be summarized as follows:
Reliable siphon operation in the slag-free tapping of an electric arc furnace or generally the melt transfer between metallurgical vessels, the siphon well to maintain and gege if necessary, it is quickly exchangeable.

The transfer the melt does not require a tilting movement.

When transferring the melt, the melt comes in no significant contact with the ambient air, so that the gas absorption decreases or prevents becomes.

It There are no restrictions on metallurgical vessels in the use of conventional vessels and also the arc furnace are only minor modifications necessary.

By the negative pressure and an optional injection of inert gas can the tapping or the transfer of Melt used to improve the metallurgical purity of the Melt.

Of the Height difference between melt channel inlet and outlet can be made larger than the metallostatic ones Height in the vessel to be emptied, so that with the same outlet cross-section a larger one Mass flow can be achieved.

The Melt can be purified with a customized system.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10223906 A1 [0002, 0003]
• - EP 1181491 B1 [0004]

Claims (10)

Apparatus for slag-free tapping or for transferring a melt from a metallurgical vessel ( 1 . 2 . 3 ) in another metallurgical vessel with a siphon-like, inverted U-shaped configuration, wherein the siphon ( 4 ) an entrance channel ( 5 ), a connection channel ( 6 ) and an exit channel ( 7 ), and the inlet channel ( 5 ) and the exit channel ( 7 ) can be immersed in the dispensing or receiving vessel, characterized in that the siphon ( 4 ) is designed as an independent, mobile unit. Device according to claim 1, characterized in that with the outlet channel ( 7 ) an adjustable device ( 12 ) is provided for generating a negative pressure in this channel, so that the melt flow in the channel initiated, maintained and can be interrupted by lifting the negative pressure again. Device according to claim 1 or 2, characterized in that at least one vessel ( 1 . 2 ) can be moved in height around the metallostatic height in the vessel to be emptied, so that a larger mass flow can be achieved with the same outlet cross section. Device according to one of claims 1 to 3, characterized in that for detecting the degree of filling of the melt, the channel system, a sensor ( 15 ) assigned. Device according to one of claims 1 to 4, characterized in that the detected ride height control technology can be linked to the vacuum generation is. Device according to one of claims 1 to 5, characterized in that to support the melt flow in the inlet channel ( 5 ) Inert gas ( 13 ) can be introduced. Device according to one of claims 1 to 6, characterized in that for the detection of entrained slag in the inlet channel ( 5 ) a slag detection system ( 14 ) is installed. Device according to claim 7, characterized in that for slag detection an induction coil around the inlet channel ( 5 ) or connection channel ( 6 ) is arranged around. Device according to one of claims 1 to 8, characterized in that to minimize the temperature drop of the melt during transfer or for introducing additional heat into the melt around at least one of the channels an induction heater ( 9 ) is installed. Device according to one of claims 1 to 9, characterized in that the ends of the inlet channel ( 5 ) and the exit channel ( 7 ) are formed exchangeable.