GB2160803A

GB2160803A - Sliding gate valve for the outlet of a metallurgical vessel

Info

Publication number: GB2160803A
Application number: GB08515554A
Authority: GB
Inventors: Karl-Otto Hornung
Original assignee: Stopinc AG
Current assignee: Stopinc AG
Priority date: 1984-06-20
Filing date: 1985-06-19
Publication date: 1986-01-02
Also published as: CA1255898A; JPS63196352U; CH663368A5; JPS6114071A; GB8515554D0; GB2160803B; DE3426107A1; FR2566302A1; FR2566302B1; DE3426107C2

Abstract

A sliding gate valve 10 for the horizontal outlet of a metallurgical vessel 12 includes two valve members 25, 26 which are relatively slidable in a sliding direction L whilst substantially maintaining a seal between them. Each valve member has a substantially rectangular, elongate flow opening 25', 26' respectively whose longitudinal axes extend parallel to one another but transverse to the sliding direction. <IMAGE>

Description

SPECIFICATION Sliding Gate Valve for the Outlet of a Metallurgical Vessel The invention relates to sliding gate valves for the outlet, in particular horizontal outlet, of metallurgical vessels and is particularly concerned with such valvesforvessels having a horizontal outlet.

The provision of metallurgical vessels, e.g.

pouring furnaces or pouring distributors, with a horizontal or at least approaching horizontal outlet which is controlled by a sliding gate valve mounted on the side wall of the furnace has proved to be very satisfactory, particularly in the nonferrous metal casting industry. When the sliding gate valve is open the melt flows out in a horizontal direction and is subsequently passed, for instance, directly into a casting mould. The refractory valve plates commonly have round flow openings which produce a tight stream of melt which is strongly turbulent at the outlet of the sliding gate valve and which on impingement, e.g. with the side of the pouring gate of a casting mould, can cause an undesirable spraying or splashing and waves on the melt in the pouring opening.The formation of oxides is also promoted in the melt which can produce a reduction in quality of the metal in its solidified state.

Furthermore, it is desirable to be able to pour precisely dosed quantities of melt in rapid sequence with such sliding gate valves. However, if the valve plates have round flow openings a relatively large distance must be travelled by the sliding plate in order to close the valve. Delays in the interruption of the outflow of the melt thus occur which render the precise dosing of the melt more difficult.

It is an object of the present invention to provide a sliding gate valve particularly for the horizontal outlet of a metallurgical vessel which causes the metal melt to flow out uniformly and substantially in a laminar manner from the sliding gate valve and which enables the melt to be rapidly and precisely dosed.

According to the present invention a sliding gate valve for the outlet of a metallurgical vessel includes at least two valve members which are relatively slidable in a sliding direction whilst substantially maintaining a seal between them, each valve member having at least one elongate flow opening, the longitudinal axes of the flow openings extending parallel to one another and transverse to the sliding direction. The flow openings which are elongate or generaliy slot-shaped are preferably of substantially rectangular section and the length of the rectangle may be three of four times its breadth.

The use of elongate flow openings which extend parallel to one another produces a flow of the melt which is uniformly distributed over the entire cross section of the flow openings and a relatively flat flow of small depth. By virtue of the fact that the sliding direction, that is to say the direction in which the sliding member or plate moves relative to the fixed member or plate, extends transverse to the longitudinal axes of the flow openings a rapid and precise dosing of the melt may be achieved in a simple mamner. The valve may include an inlet sleeve and/or an outlet sleeve situated adjacent a respective valve member and in this event the inlet and/or outlet sleeve preferably has an elongate flow opening in it whose longitudinal axis is in registry with that of the flow opening in the respective valve member.It is preferred that the corners of the flow openings are rounded since this not only substantially prevents the flow openings becoming clogged at the corners but also substantially reduces the danger of cracks forming in the valve members and in the inlet and outlet sleeves.

The invention also embraces a metallurgical vessel whose outlet is controlled by such a valve and in this event it is preferred that the outlet is substantially horizontal and that the longitudinal axes of the flow openings extend substantially horizontally also.

Further features and details of the invention will be apparent from the following description of certain exemplary embodiments which is given with reference to the accompanying drawings, in which: Figure 1 is a perspective schematic view of a sliding gate valve in accordance with the invention in situ in a metallurgical vessel; Figure 2 is a perspective schematic partly sectioned view of a sliding gate valve with an outlet sleeve; Figure 3 is a perspective schematic partly sectional view of a sliding gate valve without an outlet sleeve; and Figure 4 is a schematic elevation of the valve plates of a sliding gate valve.

The sliding gate valve 10 illustrated in Figure 1 is mounted on the side wall 14 of a metallurgical vessel 12. The valve is of linear type and comprises substantially a slider housing 20, a linear drive unit 22, a protective hood 28, sliding and fixed refractory valve plates 25 and 26 respectively, a refractory inlet sleeve 27 and a refractory tapping spout 30. The sliding plate 25 is connected to a slider carrier (not shown) which is connected to be moved in the vertical direction by the drive unit 22. Not all the features of the sliding gate valve 10 are referred to but only those which are of significance to the present invention.

The drive unit 22, which is e.g. a hydraulic piston/cylinder unit, enables the opening and closing of the valve by moving the valve plate 25 together with the tapping spout 30 to be controlled either manually or automatically. The sliding valve plate 25 is in sealing and sliding contact on one side with the fixed valve plate 26 and is connected on the other side to the tapping spout 30 which thus moves with it. The inlet sleeve 27 which constitutes a nozzle brock is in sealing engagement with the fixed plate 26 and is also firmly built in to the wall of the vessel 12. An intermediate sleeve 15 enables the sleeve 27 to be secured in position and removed again.In accordance with the invention both the valve plates 25 and 26 and also the inlet sleeve 27 are each provided with an elongate or slot-shaped flow opening 25', 26' and 27' respectively and the tapping spout 30 includes a bed 30' whose shape corresponds to that of the lower portion of the flow opening 25'. The flow openings 25', 26' and 27' are so oriented that their longitudinal direction or axis A extends in the horizontal direction. In the open position of the sliding gate valve 10, illustrated in Figure 1, the flow openings are in registry with one another. The flow opening 27' in the inlet sleeve 27 is conically flared at 27" towards the interior of the vessel 12 at its upstream end which provides a smooth flow of the melt into the outlet 16.

When the sliding gate valve 10 is opened, the melt, which may be aluminium, within the vessel 12, which may be constructed as a smelting furnace, flows into the outlet 16 which is situated directly above the base 13 of the vessel 12 and is distributed uniformly over the entire breadth of the flow openings 27', 26' and 25' and the bed 30' of the tapping spout 30. There is thus a flat, uniform stream of the outflowing melt at the outlet point 30" of the sliding gate valve which is distributed over the entire breadth of the tapping spout 30.

Due to the fact that the valve plate 25 is movable transverse to the longitudinal axis of the flow openings, the flow openings 25' and 26' of the two valve plates 25 and 26 define a flow cross-section which produces a stream of melt when they are in the throttled position with a geometrical shape similar to that in the fully open position. Thus a further advantage of the construction of the present invention is that a uniform and substantially turbulence-free outflow of the metal melt is produced both in the fully open and in the throttled positions of the sliding gate valve.

In the sliding gate valve 10 shown in Figure 2, a tubular outlet sleeve 24 of the type which is commonly used with sliding gate valves is provided instead of a tapping spout The outlet sleeve 24 is, in this case, maintained in sealing abutment with the valve plate 25 by means of a mechanical connection with the slider carrier (not shown). The outlet sleeve 24 is, in accordance with the invention, constructed with a slot-shaped or elongate flow opening 24' which in the open position of the valve is in registry with the flow opening 25'.

The sliding gate valve 10 of Figure 3 has neither an inlet nor an outlet sleeve. In orderto minimise the heat and quality losses of the outflowing melt it is desirable that the melt flows from the vessel 12 by the most direct route possible into, for instance, a not illustrated casting mould or a fixed collecting gulley (not shown). This is achieved in the construction of Figure 3 in which a sleeve 34 is provided on the inlet side with a significantly larger flow opening 34' than that of the inlet sleeve 27 of Figure 1. On the outlet side no sleeve or spout is provided and the melt flows directly into e.g. the casting mould after leaving the flow opening 25'.

In Figure 4 the valve plates 25 and 26 are shown ii the closed position. One can clearly see that the slot-shaped construction of the flow openings 25' and 26' and that their longitudinal axes A and A' arf parallel and that these axes are horizontal.

Claims

1. A sliding gate valve for the outlet of a metallurgical vessel including at least two valve members which are relatively slidable in a sliding direction whilst substantially maintaining a seal between them, each valve member having at least one elongate flow opening, the longitudinal axes ol the flow openings extending parallel to one anothe and transverse to the sliding direction.

2. A valve as claimed in claim 1, including an inlel sleeve and/or an outlet sleeve which is situated adjacent a respective valve member and has an elongate flow opening in it whose longitudinal axis is in registry with that of the flow opening in the respective valve member.

3. Avalve as claimed in claim 1 including a tapping spout on the outlet side having a bed defining a flow passage whose shape and size are substantially the same as those of part of the flow opening in the adjoining valve member.

4. A valve as claimed in any one of the preceding claims in which the flow openings are of substantially rectangular shape with rounded corners.

5. A sliding gate valve for the outlet of a metallurgical vessel substantially as specifically herein described with reference to any one of Figures 1 to 3 of the accompanying drawings.

6. A inetallurgical vessel having a horizontal outl controlled by a valve as claimed in any one of the preceding claims in which the longitudinal axes of the flow openings extend substantially horizontally