Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0637—Accessories therefor
  • B22D11/064—Accessories therefor for supplying molten metal

Definitions

• Belt casting machine consisting of at least one moving cooling surface, in particular a casting wheel with an upstream casting nozzle or tundish
• the invention relates to a strip casting machine, consisting of at least one moving cooling surface, in particular a casting wheel, with an upstream casting nozzle or an upstream tundish and a melt feed, which has a pressurized melt container with a riser pipe leading to the tundish or to the casting nozzle.
• a strip casting machine for the casting of thin strips, a strip casting machine is known, in which the melt is introduced from above from a pan through a pipe into a tundish, from which the melt flows in the desired bandwidth onto a cooled casting wheel (EP 0 463 225 A2).
• a prerequisite for high quality tapes, especially thin tapes, is that the flow rate of the melt in Tundish is as uniform as possible across the entire bandwidth. Since the melt flowing into the tundish from above through the tube has a relatively high flow rate due to the metallostatic height of the melt vessel. The extreme relationship between the pipe and tundish cross-sections leads to strong turbulence due to this high flow velocity and thus to unfavorable flow conditions in the tundish.
• melt When casting film using a nozzle, it is known to supply the melt from a heated pressurized melt container.
• the turbulence described does not occur with this solution because the melt introduced into the tundish or fed to the casting nozzle is not exposed to the metallostatic pressure of the melts located in a melt container above the tundish or the casting nozzle.
• the melt is conveyed in a controlled manner, preferably via a riser pipe, from below into the tundish or to the casting nozzle by pressurizing the melt container.
• Turbulence as the melt 'enters the tundish and changing levels of the Melt in the tundish can be greatly reduced in this way, so that the main causes for a melt flow rate that varies over the range do not exist.
• a disadvantage of this melt supply is that the refilling of the melt into the melt container is only possible discontinuously. In order to be able to pressurize the melt container, it is necessary to shut off its refill device.
• the invention has for its object to provide a strip casting machine with which the melt can be controlled for the purpose of a flow rate of the melt in the tundish or in the pouring nozzle that is as uniform as possible over the bandwidth and continuously fed to the tundish or the pouring nozzle.
• the need to refill the melt into the casting vessel should not adversely affect the conditions for conveying the melt to the tundish or the pouring nozzle.
• melt container has at least two chambers which are connected to one another in the manner of a communicating tube and can be subjected to pressures, from the first chamber of which the riser pipe leading to the tundish or to the pouring nozzle emanates and the latter for refilling second chamber set up by melt is connected in the manner of a communicating tube to a riser, which extends to above the level of the tundish or the pouring nozzle, the pressures in the two chambers being adjustable such that melt from the first chamber is continuous via the associated one Riser pipe is fed to the tundish or the pouring nozzle.
• the rate of delivery of the melt to the tundish or to the pouring nozzle can be controlled via the pressurization of the melt in the two chambers, so that the conditions in the tundish or on the pouring nozzle remain the same throughout the casting process. Since the melt container is divided into two chambers and the refill of the melt takes place in the second chamber, which is not directly upstream of the tundish or the pouring nozzle, the metallostatic pressure of the melt flowing into the melt container from a reservoir cannot determine the flow rate in the tundish or influence on the pouring nozzle. In addition, the metallostatic pressure during the refilling of the melt into the melt container can be taken into account when setting the pressures that are decisive for the conveyance.
• the riser Since the riser reaches at least to the level of the tundish or the pouring nozzle, it can be kept open for refilling the melt during the entire casting process, so that the melt can be refilled at any time.
• the pressurization of the two chambers has the further advantage that when starting the casting process, the melt can be pumped up and out of the tundish or the pouring nozzle several times, whereby the riser pipe is heated and premature solidification of the melt in the riser pipe leading to the tundish can be avoided.
• a filling tube for the melt opening into the second chamber forms at least partially the riser.
• the ascending vessel is formed exclusively by the filling pipe.
• a relatively long filling tube, practically reaching to the bottom of the second chamber, is required.
• a shorter filling pipe is sufficient if the second chamber is made up of a flow chamber and a Refill chamber for the melt is divided, wherein the flow chamber is designed as the pressurizable part and is connected to both the first chamber and the refill chamber forming the riser in the manner of a communicating tube.
• 1 is a band casting machine with tundish and two casting wheels
• Fig. 2 shows a band casting machine with tundish and two casting wheels in a different embodiment to Fig. 1, and
• Fig. 3 shows a part of a strip casting machine with a casting nozzle and a casting wheel.
• the belt casting machine shown in Fig. 1 consists essentially of a preferably heated melt container 1, a tundish 2 and cooled casting wheels 3 » 4 of different sizes, of which 4 thin strip is cast onto the larger casting wheel.
• the melt container 1 can be filled with melt from a melt container 6 arranged above it via an outlet pipe 9 and a fill pipe 10 which can be shut off with a stopper 7 and a slide closure 8.
• the melt container 1 is subdivided into a first chamber 11 and a second chamber, the second chamber being subdivided once more into a feed chamber 12a and a refill chamber 12b.
• Partition walls 13, 14 are provided between the individual chambers 11, 12a, 12b, which have passages 13a »14a at the bottom of the container 1, so that the adjacent chambers 11 / 12a and 12a / 12b are connected to one another in the manner of communicating tubes.
• the height of the refill chamber 12b reaches at least the level of the tundish 2.
• the refill tube 10 is open at the top and is designed as a funnel, so that melt can be introduced into the refill chamber 12b at any time via the refill tube.
• Both the first chamber 11 and the flow chamber 12a are otherwise closed. They are connected to pressure lines 15a, 15b of a control device 15 in order to be able to pressurize them.
• a peculiarity of the tundish 2 is that its bottom has a bulge in the central area, the purpose of which is to compensate for the impairment of the flow rate of the melt due to friction on the side walls.
• the melt vessel 1 is filled with melt from the reservoir 6.
• load cells are used under the melt vessel 1.
• the chambers 11, 12a can be pressurized via the pressure lines 16a, 16b.
• the Flow chamber 12a With a higher pressure ensures that the level of the melt does not rise in the flow chamber 12a and in the chamber 11 and the refill chamber 12b.
• the melt can be pumped up to the tundish 12. If the pressure in the chamber 11 is subsequently reduced, the melt flows from the tundish back into the chamber 11.
• the riser pipe 15 is heated up and prevents melt in the riser pipe 15 from being extracted by this heating is, remains.
• the two chambers 11, 12a are pressurized such that the melt reaches the level shown in FIG. 1 in the tundish 2 in order to be able to cast the strip 5.
• the refill vessel 12b which is also designed as a rising vessel, has the same level of melt as in the tundish 2. From the flow chamber 12a, the melt can be applied to the tundish 2 via the first chamber 11 and the riser pipe 15 by appropriate pressure are conveyed until the openings 13a, 14a at the bottom of the melt container are almost reached, without the melt having to be filled from the reservoir 6 into the refill chamber 6b during this time.
• the necessary control of the pressures in the two chambers 11, 12a is carried out by the control device 16 as a function of the monitored level of the melt in the tundish 2.
• control device 16 adjusts the pressurization of the chambers 11, 12a in such a way that the level of the melt in Tundish 2 remains constant.
• the embodiment of the band casting machine according to FIG. 2 differs from the embodiment of FIG. 1 essentially only in that the second chamber 112 is not divided into two chambers, one chamber of which forms the riser.
• the ascending vessel is formed by the filling tube 110, in which the melt level corresponds to the melt level in the tundish 102.
• the riser pipe 115 leading to the tundish 102 is not vertical, but inclined and is equipped with a heating device 115a. Since the structure and function of this casting machine coincides with that of the exemplary embodiment in FIG. 1, there is no need to go into this in greater detail.
• the corresponding parts have reference numerals raised by the number 100.
• FIG. 3 differs from that of FIG. 1 only in that instead of the tundish 2, a casting nozzle 20 and only one casting wheel 24 are provided.
• the corresponding parts here have reference numerals raised by the number 20. It goes without saying that in this embodiment an inclined riser pipe and / or a further subdivision of the second chamber is alternatively possible.
• the pressure in the casting nozzle 20 is monitored in the case of a casting nozzle.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6470202

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (1)

Citations (5)

• 1992
  • 1992-10-10 DE DE19924234259 patent/DE4234259C1/de not_active Expired - Fee Related
• 1993
  • 1993-09-30 WO PCT/EP1993/002655 patent/WO1994008742A1/de active Application Filing
  • 1993-10-08 CN CN 93118891 patent/CN1088861A/zh active Pending
  • 1993-10-09 TW TW82108393A patent/TW247283B/zh active

Patent Citations (5)

Also Published As

Similar Documents

Legal Events