Note: Descriptions are shown in the official language in which they were submitted.
23843~
The present invention relates to sliding gate valves for
the outlet, in particular the horizontal outlet, of a metall-
urgical vessel and is particularly concerned with such valves for
vessels 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 passedS for instance,
directly into a casting~mould. The refractory valve plates commonly
have round flow opentngs~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 o the pouring gate of a
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casting mould, can cause an undesirable spraying or splashing and
waves on the melt in the pour mg openlng. The formation of oxides
is also promoted~in the melt, which can produce a reduction in
quality of the metal in lts solidified state.
~20 Furthermore, it lS desirable to be able to pour precisely
dosed ~uantities 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.
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lt is an object of the present ;nvention to provide a
sliding gate valve, particularly for the horizontal outlet o a
metallurgical vessel~ which causes the metal melt to 10w 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
o the 10w openings extending parallel to one another and trans- : -
verse to the sliding direction. The 10w openings which are elonga*e
or generally slot-shaped are preferably o substantially rectangular
section and the length of the rectangle may be three or our times
its breadth.
The use of elongate flow openings which extend parallel to
one another produces a flow o the melt:which Is uniormly dist- : ~;
ributed over the~entire cross-section of the flow openings and a
relatively flat flow o small depth. The fact that the sliding
direction~ that is to say the direction ln which the sliding member
or plate moves relative to the fixed member or plate, extends trans-
verse tc the longitudinal~axes of the flow openings means that a
rapid and precise dosing of the melt may be acllieved in a simple
manner. 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
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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 sub-
stantially prevents the flow openings from 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 pre-
ferred that the outlet is substantially horizontal and that the
longitudinal axes of the flow openings extend substantially horizon-
tally also.
Further features ancl details of the invention will be
apparent from the following description of certain exemplary embodi-
ments which is given with reference to the accompanying drawings, in
; which:
Figure 1 is a perspecitve 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
~20 of a sliding gate valve with an outlet sl~eeve;
Figure 3 is a perspective sehematic, partly sectioned 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 slidlng gate~valve 10 illustrated in Figure 1 is
mounted on the side wall 14 of a metallurgical vessel 12. The valve
is of l mear type and comprises substantially a slideT housing 20, a
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linear dr:ive 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 m the vertical directlon by the drive unit 22.
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Not all the features o~ the sliding gate valve 10 are
referred to but onl those which are o signific~nce to
the present invention-
The drive unit 22, which is e.~, a h~draullc piSton/
5. cylinder unit, enables the open:in~ and closing of thevalve by moving the valve plate 25 together with the tapping
- spout 30 to be controlled either manuall~ 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
10. on the other side to the tapping spoUt 30 which thus moves
with it. The inlet sleeve 27 which constitutes a nozzle
brick is in sealing engagement with the fixed PIate 26
and is also firmly built ;in to the wall of~the vessel 12.
An intermediate sleeve 15 enables the sleeve 27 to be
15. secured in position and removed again. In accordance with
the invention both the vaLve pIates 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 spo;ut 30 includes a bed 30' whose~ shape corresponds
20. to that of the~lower portion of the~flow opening 25'.~ The
flow openings~25',26' and 27' are~so~oriented that thelr
longitudlnal~dlrection or~axis A ~extends;~in the~horizontal
direction. ~In the open position of the~sliding gate valve
lO,;illustrated in Figure l, the flow openings are in
5- ~registry with one~another. ~The~flow opening 27~' in the lnlet
sleeve 27 is~coni~cally 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~l6.~
When the sliding gaté~valve 10 is opened, the melt,
30- which may be~aluminium, within~the vessel 12, which may be
constructed~as~a~smelting furnace,flows~into the outlet 16
which is situa-ted;directly~above the Dase~13 of~the vessel 12
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and is distributed uniformly oVer the entiXe breadth of
the flow openings 27', 26' and 25~ and the bed 3Q' of the
tapping spout 30. There is thus a flat, unifonn stream
of the outflowing melt at the outlet point 30" ~f the
S. 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 o~ the flow o~enings,
the flow openings 25' and 26' of the two valve plates 25
10. 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 thé fully open position.
Thus a further advantage of the construction of the present
invention is that a uniform and substantially turbulence-
15. free outflow of the metal melt is produced both in the fullyopen and in the throttled positions of the sliding gate
valve.
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In the sliding gate valve 10 shown~in Figure 2, a
tubular outlet sleeve 24 of~the type which i5 commonly used
20. with sliding gate valves is provlded~instea~d~of ~a tapplng
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~t~he~slider carrier (not shown).
;; The outlet sleeve 24~ is, in accordanCe with the invention,
25. constructed wlth a ~slot-shaped or elongate flow opening 24'
which in the open position of the valve is in registry
with the flow openin~ 25'. ;
The sliding gate~valve 10 of~Figure 3 has neither an
inlet nor an outlet sleeve. In o~rder to~minimise the~heat
30-~ and quality losses of the;outflowing~melt~it is desirable
that the melt flows from the vessel 12 by the most direct
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route possible into, for instance, a not illustrated casting mould
or a fixed collecting gulley ~not shown). This is achievcd 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 in~et 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 th,e valve plates 25 and 26 are shown iJI
the closed position. ~ne can clearly see the slot-shaped construction
io of the flow openings 25' and 26' and that their longitudinal axes
A and A' are parallel ana that these are~ are horiz ntal.
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