Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/14—Closures
  • B22D41/22—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings
  • B22D41/24—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings characterised by a rectilinearly movable plate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/14—Closures
  • B22D41/22—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings
  • B22D41/28—Plates therefor

Definitions

• the invention relates to a method and a device for regulating a liquid inflow into a vessel, in particular into a flow vessel, slide plates with flow openings being moved relative to one another and the flow rate being regulated in the process.
• slide devices have also proven themselves for regulating the flow of melts, such as glass, metal, etc., in particular in steelworks for casting steel in a continuous casting process.
• the aim of the invention is to improve the setting and the maintenance of a predetermined flow rate, in order to increase the surface quality of cast strands, particularly during continuous casting. At the same time, the service life of slide plates is to be extended by reducing the wear on the flow openings. Another goal is to improve the formation of the pouring stream after it emerges from the slide.
• the method and the device according to the invention make it possible for the first time to achieve a sum of advantages which can be weighted differently depending on the field of application. It is particularly advantageous in continuous casting if fine adjustment over a long casting time is possible in the area of the target flow rate of the slide in order to be able to precisely control or maintain the bath level in the mold. The strand quality can thus be improved.
• the regulation problems during casting such as adapting the casting rate to a desired mold filling speed, are also solved and a compact, non-fluttering pouring jet is achieved.
• the greatest possible freedom of dimensioning, in particular the flow cross-sections chosen for the plates, advantageously reduces wear on the edges of the flow openings and thus extends the period of use with high regulation accuracy.
• the wedge-shaped flow opening further reduces the vortex formation directly in front of and in the flow opening of the slide and thus also the elimination or the addition of aluminum oxide deposits in the slide and in its surroundings.
• the known high-frequency vibration movement of the slide plates during the casting operation can be replaced or supplemented by a low-frequency oscillation movement with a relatively long stroke in accordance with a further method variant while maintaining constant inflow rates.
• the oscillation movement is usually in the same direction as the relative movement.
• centering or a constant position of the central axis of the pouring jet is also desirable while the pouring rate is being changed.
• the first and the second slide plate are moved simultaneously or in succession and the pouring jet is regulated and moved in a centered position or, if desired, shifted.
• the cross-sections of the flow openings of both plates can be designed within the defined teaching.
• the wedge-shaped flow opening can be delimited by straight, convex or concave, wave-shaped, etc. surfaces.
• the converging wedge lines are generally connected by an arc line on at least one side.
• the relative movement in the longitudinal direction of the wedge-shaped flow opening can be straight or, in the case of a rotary slide, curved.
• the flow opening of the second plate can be round, oval, trapezoidal, rectangular or polygonal.
• An adaptation of the flow rate depending on the movement path can be achieved in a wide range before and after the bridging by shaping and dimensioning the flow openings.
• the control rate after the bridging in the desired range of the casting power, is lower than before the bridging, while the speed of movement remains the same.
• the control rate for the same displacement path after the bridging should be approximately 1/3 to 1/2 of the average control rate before the bridging.
• this vortex formation is to be substantially reduced according to one embodiment.
• the longitudinal axis of this elongated hole lies parallel to the longitudinal axis of the wedge-shaped flow opening of the first slide plate, the length to width ratio of the elongated hole can remain the same over the entire height of the inlet cone. According to this teaching, it is possible to guide the flow of the melt before the slide entry without swirls and with a minimum of turbulence. As a result, the degree of purity of the outflowing melt can be further improved.
• turbulence can be additionally reduced.
• the longitudinal axis of the flow cross-sectional area lies parallel to the longitudinal axis of the wedge-shaped flow opening of the first slide plate.
• the dimensioning of the flow cross-sections of the elongated holes can be strengthened for one or the other objective.
• Advantageous results are achieved if the cross-sectional area of the elongated holes has a width to length ratio of 1: 1.5 to 1 s 4.
• the elongated holes can be wedge-shaped, oval, rectangular with correspondingly small grooves in the corners, etc.
• Fig. 4 shows another example of a schematic
• FIG. 5 shows a section through a three-plate slide according to FIG. 4,
• Fig. 6 is a vertical section through a spout of a metallurgical vessel
• FIG. 7 is a plan view of the spout according to FIG. 6.
• the length 1 of the wedge is greater than d.
• the wedge length 1 is preferably 1.25-2.5 d.
• the width d. is measured in direction 5 of the relative movement of the plates.
• the wedge height h .. on the narrow wedge side is smaller than the width ⁇ , which is measured transversely to the direction of movement 5.
• H_. is smaller than the dimension h_, that of the K ⁇ il cramp on the thick Wedge side corresponds.
• the flow openings 3 and 4 thus have defined different geometrical configurations. Instead of the round or square flow opening 4,4 ', oval, trapezoidal, rectangular or polygonal etc. openings could be selected.
• FIG. 2 the wedge-shaped flow opening is shifted further to the right compared to FIG. 1.
• the throughflow opening 3 bridges the round opening 4.
• a further shift after the bridging of the opening 4 into a position 6 is shown in broken lines.
• the displacement path can be recognized by arrow 7 or by the dimension line X.
• the open slide cross-sectional area which determines the flow rate has increased only by the hatched areas 9, 9 '.
• the control range after bridging the flow opening 4 by the wedge-shaped flow opening 3 represents a fine adjustment range
• the change in the casting rate or the change in the open slide cross-sectional area Delta A from the conicity or angle alpha of the wedge-shaped flow opening, the average bridging length S before and after the displacement and from the displacement path X during the relative movement can be calculated using the following formula:
• a first curve branch between 0 and 14 shows an approximately proportional increase in the Pouring rate or increase in the open slide cross-sectional area. The bridging is completed at curve point 14 and the increase in the pouring rate is smaller compared to the curve branch 0-14.
• the curve branch 14-15 represents the fine adjustment area.
• the increase in the pouring rate in the fine adjustment area (14th to 15) is about 1/2 to 1/3 of the increase in the control range before the bridging (0 to 14) with the same displacement path.
• FIGS. 4 and 5 show an example with a slide which consists of 3 plates 30-32 arranged one above the other.
• An attached pouring tube 34 is indicated.
• the plate 31 with a wedge-shaped flow opening 35 is moved in the direction of the arrow 36 when it is opened.
• the plate 32 can be moved with a round flow opening 37 in the direction of the arrow 38.
• a e.g. Round opening 39 of the plate 30 remains.
• the pouring jet can be centered.
• Dash-dotted lines indicate a displacement of the plate 32 together with the pouring tube 34.
• a vibration movement known from the prior art can be applied to one or both plates 31, 32 in the case of two-plate or three-plate slides.
• this slide in particular in the fine adjustment range, can have a relatively slow oscillation frequency, e.g. a frequency that is less than 1 stroke / sec and a relatively large stroke length between 1 mm and 5 mm, preferably between 2 mm and 4 mm, are applied because there are no negative effects on changes in the casting rate to be feared. This reduces wear on the slide plates.
• FIG. 6 and 7 schematically show 60 a first slide plate with a wedge-shaped flow opening 61 and 62 a second slide plate with an essentially rectangular flow opening 63.
• a refractory inlet cone 65 of a casting vessel is arranged above the slide plate 60.
• the amount of this Inlet cone 65 is generally matched to the thickness of the lining of the bottom of the casting vessel.
• the angle of the converging side surfaces is designed to meet practical needs, in particular to prevent freezing and vortex formation of the melt in the inlet onus.
• the side of the inlet cone facing the slide plate 61 has a slide inlet opening 66 with a flow cross-sectional area which is matched to the flow opening of the slide plate 61.
• This flow cross-sectional area has the shape of an essentially wedge-shaped or rectangular elongated hole, the longitudinal axis of which lies parallel to the longitudinal axis 70 of the wedge-shaped flow opening at the first slide plate 60.
• 7 shows a wedge-shaped flow cross-sectional area 71 in the upper half of the drawing and a rectangular flow cross-sectional area 72 in the lower half.
• the width-to-length ratio of the square flow cross-section opening 71, 72 remains constant on the higher-lying flow cross-sectional areas 64 within the inlet cone.
• the length A of the cross section can also be adapted to the needs of suppressing the vortex formation, ie it can be chosen, for example, to be greater than the length of the wedge-shaped flow opening 61.
• a protective tube 67 is arranged on the melt outlet side of the slide, which has a flow cross-sectional area in the form of an elongated hole.
• the longitudinal axis of the cross-sectional area runs parallel to the longitudinal axis of the wedge-shaped flow opening.
• the protective tube 67 has a rectangular cross-sectional area.
• the length of the cross-sectional area is generally adapted to the length of the flow opening of the second slide plate 62. It can also be longer.
• the width B 2 is matched to the height h_ of the thick wedge side.
• the elongated hole of the inlet cone at the slide inlet opening 66 and / or the elongated hole 69 of the protective tube 67 can be dependent on each other with a width to length ratio of preferably 1: 1.5 to 1: 4.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
• Sliding Valves (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4261545

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (4)

• 1988
  • 1988-09-15 WO PCT/CH1988/000160 patent/WO1989002801A1/de unknown
  • 1988-09-15 AU AU23183/88A patent/AU2318388A/en not_active Abandoned
  • 1988-09-23 ES ES888803269A patent/ES2011174A6/es not_active Expired

Patent Citations (4)

Non-Patent Citations (1)

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