GB1584628A

GB1584628A - Sliding gate valve

Info

Publication number: GB1584628A
Application number: GB40175/77A
Authority: GB
Original assignee: USS Engineers and Consultants Inc
Current assignee: USS Engineers and Consultants Inc
Priority date: 1976-10-15
Filing date: 1977-09-27
Publication date: 1981-02-18
Also published as: AU512164B2; ATA737177A; YU242677A; FR2367569B1; SU1087057A3; CH627103A5; AR212108A1; FI773027A; NL7711330A; IN147808B; PL201497A1; SE7711361L; BE859765A; SE433713B; DE2746265A1; RO79167A; CS216909B2; DD133700A5; MX146103A; NL182455C

Abstract

For the adjustable throttling of the casting stream in the case of a casting vessel (1) with exchangeable or displaceable sliding plates (13), a slide valve is provided for carrying out the method. By means of a second moving device (17), which operates independently of a first moving device which brings about the exchange or displacement movement of the sliding plates (13), the axial alignment of the pouring opening of the sliding plate (13) relative to the pouring opening of the casting vessel (1) can be varied in such a way that finely adjusted throttling is achieved. Depending on the properties of the molten material to be cast, it is thus possible to set the pouring cross-section which has been recognised as the optimum and for it to be varied in the course of the casting process. To improve the throttling effect, the pouring opening formed in the sliding plate (13) can have an elongated cross-section. The second moving device comprises a hydraulic throttling cylinder (17), which engages on a holding frame (6) for the sliding plate (13). <IMAGE>

Description

(54) SLIDING GATE VALVE (71) We, USS ENGINEERS AND CONSULTANTS INC., a corporation organised and existing under the laws of the state of Delaware, United States of America of 600 Grant Street, Pittsburgh, State of Pennsylvania 15230, United States of America do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to sliding gate valves for the pouring or teeming of molten fluids such as steel, iron, aluminum, brass, and glass, which are only fluid at temperatures elevated above normal ambient temperatures.

The field of invention is generally described in United States patents Nos. 311,902; 1,507,852; 3,436,023; and 3,454,201. United States patent No. 3,352,465 and its re-issue No.

Re 27,237 discloses sequential refractory valving which is spring loaded against a fixed top plate generally indicative of the environment in which the present invention finds its utility. More recently issued United States patent No. 3,866,806 discloses a method of throttling using a check cylinder to stop a gate short of a full stroke.

Each of the above identified structures suffers from the disadvantage of being unable to adjust the degree of throttling action independent of the emergency shutoff function of the valve. Such action is particularly desirable when aluminum killed steel, in particular, is run through a continuous caster. The aluminum oxide formed as a result of the killing process has an affinity toward the side wall of the teeming opening as well as any associated pour tube. It ultimately can clog both. It is, therefore, necessary with a continuous caster to be able to change the slide valve as well as the tube. This is accomplished, particularly in the construction as disclosed in patent No.

3,352,465 (Re 27,237) by passing an imperforate plate into position, and replacing the other element.

According to the present invention, there is provided a sliding gate valve, for a teeming vessel having a teeming opening in its bottom, comprising a stationary orificed top plate for mounting in a fixed position beneath the vessel with its orifice in communication with the said teeming opening, an orificed slide plate held by biasing means fluid-tightly against the underside of the top plate and in sliding contact therewith, a slide plate frame supporting the slide plate for movement therein, the slide plate frame in turn being movably mounted relative to the top plate and two moving means operable to effect sliding of the slide plate to control metal flow through the valve, the first moving means being coupled to the slide plate alone to move it relative to the slide plate frame and the second moving means being coupled to the slide plate frame to move both it and the slide plate in unison, operation of one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice either to open or to close the valve to metal flow, and operation of the other moving means following opening of the valve by the said one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice so as to adjust the flow rate through the valve.

The invention also provides a method of teeming a molten material through a passage from a vessel such as a ladle or a tundish having a pour opening using a sliding gate valve in which an apertured slide plate is slidably mounted in a support frame beneath said teeming opening, the method comprising moving the slide plate within the slide frame to a normally .open position with respect to said pour opening, and thereafter moving the slide plate and slide frame in unison so as to adjust the rate of teeming through the slide plate aperture.

Some embodiments of the invention are described in detail by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a section through a part of a bottom pour vessel, here illustrated as a tundish, on which is mounted a sliding gate valve constructed in accordance with the invention, Figure 2 is a section on a larger scale on the line 2-2 of Figure 1 showing a slide plate and pouring tube of the valve offset, Figure 3 is a section similar to Figure 2, through a modified valve showing only the slide plate offset, Figure 4 is a section similar to Figure 1 through a part of a bottom pour vessel, here illustrated as a ladle on which is mounted a reciprocating ladle valve constructed in accordance with the invention Figure 5 is a section on a larger scale on the line 5--5 of Figure 4, Figure 6 is a section through a further embodiment of the invention shown mounted on a tundish, Figure 7 is a plan view of an opening through a slide plate of the embodiment of Figure 6, Figure 8 is a section on the line 8-8 of Figure 7, and Figure.9 is a top plan view, on a reduced scale, of the embodiment of Figure 6, shown disassembled from the tundish.

Figures 1 and 2 illustrate a tundish 1 with its refractory lining 2. Mounted on the bottom of the tundish is a fixed mounting plate 3 which holds a refractory top plate 4 in a fixed position relative to the mounting plate 3.

Support rods 5 are attached to the mounting plate 3 and slidably support a slide gate support frame 6 which carries slide gate support rails 7 shown in greater detail in Figure 2. A gate change cylinder 8 is connected to the slide gate support frame 6. Slide gate plates are inserted from position 11 to position 12, then the cylinder 8 pushes them to operating position 13 at the same time pushing a used plate from position 13 to position 14. The slide plates may be imperforate blanks for shutoff as shown at 12 or may have teeming openings as shown at 13 and 14. As shown in Figure 1, the unit is equipped with a submerged pour tube 16 although it may be operated without a submerged pour tube. The submerged pour tube 16 depends from a holder 15 which is supported by support rails 10 shown in greater detail in Figure 2 carried by a submerged pour tube support frame 9 suspended beneath the slide gate support frame 6.

As is clear from Figure 2, the support rails 7 and 10 are pivotally mounted on their respect.

ive frames 6 and 9 and are spring-loaded so as resiliently to urge the slide plate 13 against the top plate 4 and the pour tube holder 15 against the slide plate 13.

Figure 2 illustrates how throttling is accomplished. The slide gate support frame 6 is offset to the right thus causing misalignment between the orifice in top plate 4 and the orifice in the slide gate plate 13, and thus throttling the stream. The slide gate support frame 6 slides on the support rods 5 and in this instance is moved by a hydraulic throttling cylinder 17 although it could be moved by levers or screws either manually or electrically operated. In the embodiment of Figure 2 the submerged pour tube support frame 9 is rigidly connected to the slide gate support frame 6 so that the submerged pour tube holder 15 and submerged pour tube 16 are offset with the slide gate plate 13 and remain aligned with it.

In the modification shown in Figure 3, the submerged pour tube support flame 9 is fastened rigidly to the fixed mounting plate 3 so that when the hydraulic cylinder 17 offsets the slide gate support frame 6 and slide gate plate 13 as shown, the submerged pour tube support frame 9, submerged pour tube holder 15, and submerged pour tube 16 remain in alignment with the refractory top plate 4.

Figure 4 illustrates a ladle 18 with its refractory lining 19. Mounted on the bottom of the ladle is a fixed mounting plate 20 which holds a refractory top plate 21 in a fixed position relative to the mounting plate 20 and also supports a slide gate support frame 27 by means of flanged gibs 28 which are illustrated in Figure 5. A slide gate carrier 24 carrying a slide gate 25 is slidably mounted in the support frame 27.

At the position shown in Figure 4, an operating linkage 23 actuated by a cylinder 22 has pulled the slide gate carrier 24 and slide gate 25 to the right until it is against a stop built into the slide gate support frame 27. This would be its normal full open position but, as shown, a throttling cylinder 26 connected between the body of the ladle 18 and the slide gate support frame 27 has shifted the entire slide gate support frame 27 to the right a distance equal to about one-third of the width of the orifice in the plate 21 thus throttling flow through the orifice. Throttling could equally be accomplished by shifting the slide gate support frame 27 to the left. The choice as to which of these modes of operation depends on whether it is desirable to throttle on the front or back side of the slide gate orifice. The valve may be quickly shut off by extending the operating cylinder 22 without the need to operate the throttling cylinder 26.

Referring to Figure 5, the flanged gibs 28 are screwed to the mounting plate 20 by means of cap screws 29. The flange portion of the gibs 28 engage flange portions of the sliding gate support frame 27 supporting it in a fixed vertical position whilst allowing the necessary sliding motion. Stops may be affixed to the gibs 28 to limit the travel of the sliding gate support frame 27.

In Figures 6 to 9, parts which are comparable with parts shown in Figures 1 and 2 will be designated with a prime such as tundish 1', which is the vessel employed. The refractory 2' lines the interior of the tundish 1', and therebeneath a mounting plate 3' is positioned. The top plate 4' is immediately beneath the teeming opening of the tundish 1'. The frame 6' surrounds the top plate 4', and interiorly thereof are mounted slide gate support rails 7' along which the slide gates are moved by means of the drive cylinder 8' (shown on Figure 9).

A tube support frame 9' is positioned beneath the slide gate support frame 6' and has support rails generally designated 10' on which is mounted the tube holder 15'. The tube holder 15' is encased in metal as are the top plate 4' and the slide plates. The pour tube 16 extends downwardly from the tube holder 15'.

The throttling cylinder 17' drives a cross link 30 which is pivotally attached to crank arms 31 fixed to crank shafts 32. Shorter crank arms 33 are also fixed to the shafts 32 and pivotally engage yokes 34 which are provided with opposed push rods 35 which act against the slide gate support rails 7' to shift the rails 7' laterally for throttling.

Spring loaded push rods 37 activated by springs 36' bear against rocker arms 38 mounted on pivots 39' to urge the tube holder 15' against the slide plate 13' and the slide plate 13' against the top plate 4'.

As may be seen in Figures 7 and 8, the orifice in the slide plate 13' is elongate along the axis of throttling. This configuration is highly desirable to maximize the opening at the termination of pouring, prior to total clogging; and conversely to permit a relatively small total opening when the pour begins prior to any clogging. The elongate orifice shown in Figure 7 has an obround or oval configuration.

Alternatively, other configurations such as elliptical may be employed. In the total throttled condition, the plan view of the overall pour opening is preferably essentially circular, but as throttling is reduced, the overall opening becomes more closely that shown in Figure 7, obscured only by the extent to which clogging has occurred.

In this manner, maximum throttling can be achieved while maintaining a compact stream.

Further, it is contemplated that perforate plates having different short axis orifices will be used while all will have the same long axis. As the length of the long axis will be a function of the total stroke of the throttling mechanism, the maximum per cent of throttle available will be the same for each different size orifice used. In the embodiment shown in Figures 6 to 9, the stroke of the throttling mechanism is one half the long axis length of the orifice. The elongate opening allows the use of plates of various opening areas in a mechanism of fixed throttle travel while avoiding over-throttling which disrupts the stream flow and results in high erosion in the area below the point of throttle.

WHAT WE CLAIM IS: 1. A sliding gate valve, for a teeming vessel having a teeming opening in its bottom, comprising a stationary orificed top plate for mounting in a fixed position beneath the vessel with its orifice in communication with the said teeming opening, an orifice slide plate held by biasing means fluid-tightly against the underside of the top plate and in sliding contact therewith, a slide plate frame supporting the slide plate for movement therein, the slide plate frame in turn being movably mounted relative to the top plate, and two moving means operable to effect sliding of the slide plate to control metal flow through the valve, the first moving means being coupled to the slide plate alone to move it relative to the slide plate frame and the second moving means being coupled to the slide plate frame to move both it and the slide plate in unison, operation of one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice either to open or to close the valve to metal flow, and operation of the other moving means following opening of the valve by the said one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice so as to adjust the flow rate through the valve.

2. A valve as claimed in claim 1, in which the direction of movement of the slide plate in the slide plate frame is at right angles to the direction of movement of the slide plate frame.

3. A valve as claimed in claim 1 or claim 2 in which the orifice in the slide plate is elongated along an axis parallel with the direction in which the slide plate is shifted to adjust the flow rate.

4. A valve as claimed in any one of claims 1 to 3 in which said biasing means are yieldable means.

5. A valve as claimed in any one of claims 1 to 4 in which said second moving means comprises a fluid cylinder operatively connected to said slide plate frame and arranged to move said frame and said slide plate.in unison laterally with respect to the direction of movement of said slide plate imparted by said first moving means.

6. A valve as claimed in any one of claims 1 to 4 in which said second moving means comprises a fluid cylinder operatively connected to said slide plate frame and arranged to move said frame and said slide plate in unison in a direction parallel to that imparted to said slide plate by said first moving means.

7. A valve as claimed in any one of claims 1 to 5 in which said second moving means comprises a fluid cylinder coupled by means of a crank to a crank shaft, a yoke coupled by means of a crank to said crank shaft, and opposed push rods coupled to said yoke for moving said frame and said slide plate in unison laterally with respect to the direction of movement of said slide plate imparted by said first moving means.

8. A valve as claimed in any one of claims 1 to 7 in which said first moving means comprises a fluid cylinder operatively connected to said slide plate.

9. A method of teeming a molten material through a passage from a vessel such as a ladle or a tundish having a pour opening using a sliding gate valve in which an apertured slide plate is slidably mounted in a support frame beneath said teeming opening, the method comprising moving the slide plate within the slide frame to a normally open position with respect to said pour opening, and thereafter moving the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. top plate 4' and the slide plates. The pour tube 16 extends downwardly from the tube holder 15'. The throttling cylinder 17' drives a cross link 30 which is pivotally attached to crank arms 31 fixed to crank shafts 32. Shorter crank arms 33 are also fixed to the shafts 32 and pivotally engage yokes 34 which are provided with opposed push rods 35 which act against the slide gate support rails 7' to shift the rails 7' laterally for throttling. Spring loaded push rods 37 activated by springs 36' bear against rocker arms 38 mounted on pivots 39' to urge the tube holder 15' against the slide plate 13' and the slide plate 13' against the top plate 4'. As may be seen in Figures 7 and 8, the orifice in the slide plate 13' is elongate along the axis of throttling. This configuration is highly desirable to maximize the opening at the termination of pouring, prior to total clogging; and conversely to permit a relatively small total opening when the pour begins prior to any clogging. The elongate orifice shown in Figure 7 has an obround or oval configuration. Alternatively, other configurations such as elliptical may be employed. In the total throttled condition, the plan view of the overall pour opening is preferably essentially circular, but as throttling is reduced, the overall opening becomes more closely that shown in Figure 7, obscured only by the extent to which clogging has occurred. In this manner, maximum throttling can be achieved while maintaining a compact stream. Further, it is contemplated that perforate plates having different short axis orifices will be used while all will have the same long axis. As the length of the long axis will be a function of the total stroke of the throttling mechanism, the maximum per cent of throttle available will be the same for each different size orifice used. In the embodiment shown in Figures 6 to 9, the stroke of the throttling mechanism is one half the long axis length of the orifice. The elongate opening allows the use of plates of various opening areas in a mechanism of fixed throttle travel while avoiding over-throttling which disrupts the stream flow and results in high erosion in the area below the point of throttle. WHAT WE CLAIM IS:

1. A sliding gate valve, for a teeming vessel having a teeming opening in its bottom, comprising a stationary orificed top plate for mounting in a fixed position beneath the vessel with its orifice in communication with the said teeming opening, an orifice slide plate held by biasing means fluid-tightly against the underside of the top plate and in sliding contact therewith, a slide plate frame supporting the slide plate for movement therein, the slide plate frame in turn being movably mounted relative to the top plate, and two moving means operable to effect sliding of the slide plate to control metal flow through the valve, the first moving means being coupled to the slide plate alone to move it relative to the slide plate frame and the second moving means being coupled to the slide plate frame to move both it and the slide plate in unison, operation of one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice either to open or to close the valve to metal flow, and operation of the other moving means following opening of the valve by the said one moving means being arranged to shift the slide plate and its orifice relative to the top plate orifice so as to adjust the flow rate through the valve.

the slide plate and slide frame in unison so as to adjust the rate of teeming through the slide plate aperture.

10. A method as recited in claim 9 in which said normally open position is the fully throttled position of the valve and in which teeming is adjusted by simultaneously moving the side plate and slide frame to progressively increase the teeming flow to compensate for increased obstruction in the teeming flow passage.

11. A method as recited in claim 9 in which said normally open position is the fully open position of the valve and in which teeming is adjusted by simultaneously moving the slide plate and slide frame to progressively decrease the teeming flow to compensate for erosion of the teeming flow passage.

12. A method as recited in claim 9 in which said normally open position is intermediate the fully throttled and the fully open positions of the valve and in which teeming is adjusted by simultaneously moving the slide plate and slide frame to alter the degree of opening of the passage to adjust the rate of teeming from the vessel.

13. A sliding gate valve for a teeming vessel, constructed and adapted to operate substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2, or Figure 3 or Figures 4 and 5, or Figures 6 to 9 of the accompanying drawings.

14. A method of teeming molten material from a vessel such as a ladle or tundish, substantially as hereinbefore described with reference to the accompanying drawings.