US3713478A - Method for internal cooling of cast tubes - Google Patents

Method for internal cooling of cast tubes Download PDF

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Publication number
US3713478A
US3713478A US00205105A US3713478DA US3713478A US 3713478 A US3713478 A US 3713478A US 00205105 A US00205105 A US 00205105A US 3713478D A US3713478D A US 3713478DA US 3713478 A US3713478 A US 3713478A
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US
United States
Prior art keywords
mandrel
tube
water
steam
interior
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Expired - Lifetime
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US00205105A
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English (en)
Inventor
M Strohschein
J Glaser
G Vogt
J Kurth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vodafone GmbH
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Mannesmann AG
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Publication date
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    • 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
    • B22D11/006—Continuous casting of metals, i.e. casting in indefinite lengths of tubes

Definitions

  • the present invention relates to a method and equipment for internally cooling tubing produced by continuous casting of steel.
  • the equipment includes, in particular, a cooled mandrel traversed by a steam conduit.
  • German printed patent application DAS 1,099,700 discloses equipment for continuous casting of hollow tubing, wherein a cooled hollow mandrel is centrally suspended in the cavity of the casting mold. Cooling water is both fed and withdrawn from the upper end of the hollow mandrel. For additional cooling of the cast tube a water pipe traverses the hollow mandrel. A noz 'zle in the lower end of this pipe sprays cooling water onto the interior surface of the cast tube. As the water contacts the hot, interior wall of the tube, part of the water vaporizes.
  • a mandrel for cooling cast tubes from the interior, in that cooling water passes through the mandrel and leaves the same through a ring-shaped slot at the bottom, to cool directly the interior surface of the cast tube.
  • a steam pipe is provided in the interior of this mandrel for causing the steam to escape the system along a path other than the cast tube.
  • Still another device has been disclosed in German Pat. 835,326 in accordance with which cooling water leaves the bottom of a mandrel through a slot thereof and is caught in a plate resiliently urged against the surface of the formed tube.
  • the dammed cooling water is then sucked through suitable piping, traversing the mandrel, in up direction. Some air is sucked, likewise, through the gap between the plate and the interior surface of the casttube.
  • the present invention relates to a system, as well as equipment for cooling the interior of a cast steel tube when leaving the mold operating in continuous casting configuration.
  • the cooling device is constructed and proportioned such that even in case a crack develops in the tube, as was outlined above, explosions do not occur.
  • the cross sectional area of the steam escape path running through a hollow mandrel and through conduits communicating therewith is dimensioned so that the available cross sectional area in square millimeters is at least 60 fold the value of the amount of cooling water (in liters per minute) as sprayed onto the interior surface of the cast tube.
  • the figures will differ accordingly as the proportionality factor (here 60) involved in the relation is not dimen sionless, but has the dimension of minute per liter per square millimeter.
  • the size of the cross section area of the hollow part of the mandrel as steam withdrawal path is determined on basis of a particular rate of cooling water flow needed to obtain the desired internal cooling of the cast tube.
  • the rule involved in the invention can also be restated as follows:
  • the cross section of the steam withdrawal path through the mandrel must be such that in case the entire amount of water sprayed onto the interior surface of the cast tube vaporizes, the steam must be susceptible to complete withdrawal at speeds below the speed of sound in steam. in short, the rate of liquid coolant supply must not exceed an outflow rate of the same amount of coolant but in the vaporized state at a subsonic speed.
  • a steam withdrawal rate at a speed which is below the speed of sound in steam was found to be the critical condition for avoiding the development of dangerously excessive pressure in the interior of the mandrel and of the cast tube.
  • a hollow mandrel constructed in accordance with these features can, therefore, be used wherever a relatively large interior space is required. Moreover, a mandrel constructed in this manner provides smooth guidance for the liquid which cools the mandrel very effectively.
  • the steam withdrawal path is under control of a suction device.
  • the suction device maintains preferably a below normal pressure in the interior of steam pipe and mandrel. This way, not only steam is removed effectively, but certain quantities of air are likewise sucked out of the interior of the cast tube, so that the entire amount of vaporized water is withdrawn with certainty. Moreover, the sucking out of air increases the overall cooling as provided by the system.
  • FIG. 1 illustrates somewhat schematically a cross sectional view of equipment used for continuous casting of a tube
  • FIG. 2 illustrates on an enlarged scale a section through a hollow mandrel employed in the equipment shown in FIG. 1 and constructed in accordance with the preferred embodiment of this invention
  • FIG. 3 illustrates a cross sectional view, A, B in FIG. 2;
  • FIG. 4 illustrates the development of the tubular interior of the hollow mandrel.
  • FIG. 1 illustrates continuous casting equipment which includes a water cooled casting mold 1 having a cylindrical cavity. Liquid steel is fed continuously into the mold cavity in a manner known, per se. This part of the continuous casting process is conventional and needs no further description.
  • a hollow mandrel 2 is suspended in and projects centrally into the mold cavity. The mandrel is likewise water cooled.
  • a tube 3 results from the continuous casting process and is formed by cooperation of mold l and mandrel 2. Tube 3 leaves the cavity of mold l at the open bottom thereof while being only partially solidified. Essentially, there is a liquidous core 3a and inner and outer solidified regions 3b of tube 3.
  • the outer solidified region forms adjacent the cooled mold, the inner solidified portion forms adjacent the cooled mandrel. Both solidified regions increase in size in radial direction toward each other and the size of the liquidous core decreases accordingly with distance of the tube from mold and mandrel. At a certain distance from the equipment tube 3 is solidified throughout its extension.
  • the solidification is enhanced considerably by spraying the tubes surface with water.
  • the equipment may thus include conventional means for spraying the outer surface of tube 3 with water in a manner known, per se; also, there may be rolls for moving the continuously cast tube away from the mold.
  • a pipe 4 for traversing the interior of the hollow mandrel and reaching into the space circumscribed by tube 3.
  • Pipe 4 is provided with nozzles 5. Water is fed into pipe 4 and sprayed by the nozzles 5 toward the inner surface of tube 3, thereby cooling the tube 3 directly from the interior.
  • FIGS. 2 through 4 illustrate hollow mandrel 2 in greater detail.
  • the mandrel has an outer wall 9 from which the tube 3 is drawn.
  • the mandrel has an inner wall 10 and the ring space between walls 9 and 10 is subdivided by ridges 13 to form channels 11 and 12. Cooling water runs through the channels 11 and 12.
  • the individual channels 11 and 12 are grouped in pairs as represented by the designation.
  • a channel 11 is associated with an adjacent channel 12, in that they are joined in the bottom region of the mandrel to form a closed system.
  • Channel 11 of each pair is connected on the upper end of the mandrel to a water feeder line 15, while the cooling water leaves the respective channels 12 through piping 14 to which all channels 12 are connected.
  • Passing cooling water through the hollow mandrel constructed in accordance with the invention offers the advantage that the cooling system occupies little space, and there remains a rather large region 6 with a large cross sectional area through which can pass the steam which resulted from vaporization of the water sprayed through nozzles 5 onto the hot inner surface of tube 3.
  • This open region 6 serves generally as an escape and steam removal path and should be dimensioned such that even in case the entire amount of spray water turns into steam, that steam can still flow up at a speed below the speed of sound in steam so that excess pressure is never developed inside of the solidifying tube 3.
  • the cross section of flow region 6 must have dimension so that the vapor equivalent of 75 liters can flow through, in one minute's time and at a speed below the speed of sound in steam.
  • One liter of water when vaporized produces 1,700 liter steam reduced to normal conditions of zero degrees centigrade and 760 mm mercury pressure. Under the same normalized conditions the speed of sound in steam is about 440 meters per second.
  • the relationship F 2 60.Q is obtained, with Q being the amount of water actually expanded and in liters per minute, and F being the cross section of space 6 in square millimeters.
  • the cross section F must be at least equal to 4,500 mm
  • the pipe 4 is comparatively small and its dimensions can, in fact, be neglected, i.e., the space occupied by pipe 4 provides only negligible constriction of the flow path of steam through region 6. It follows then, that the mandrel must have these dimensions. As it was assumed that the tube to be cast had to have an inner diameter of 140 mm, the mandrel must have an outer diameter of 140 mm accordingly.
  • a hollow mandrel having an internal crosssection which is, in square millimeters, at least sixty times the numerical value (in liters per minute) of the flow rate of the water, the rate being sufficient to cool the tube as the tube is drawn from the hollow mandrel in a manner exposing the interior surface of the tube below the bottom of the mandrel,

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
US00205105A 1968-05-22 1971-12-06 Method for internal cooling of cast tubes Expired - Lifetime US3713478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1758393 1968-05-22

Publications (1)

Publication Number Publication Date
US3713478A true US3713478A (en) 1973-01-30

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ID=5695009

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US00205105A Expired - Lifetime US3713478A (en) 1968-05-22 1971-12-06 Method for internal cooling of cast tubes

Country Status (6)

Country Link
US (1) US3713478A (xx)
AT (1) AT286521B (xx)
BE (1) BE731799A (xx)
FR (1) FR2009059B1 (xx)
GB (1) GB1243579A (xx)
SE (1) SE348128B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886996A (en) * 1973-03-13 1975-06-03 Aron Yakovlevich Tseitlin Device for producing internal cylindrical space in ingots
US4257472A (en) * 1979-07-30 1981-03-24 Concast Incorporated Continuous casting of hollow shapes
US4729422A (en) * 1982-01-13 1988-03-08 Vallourec Process and apparatus for the production of hollow bodies by continuously casting in a magnetic field

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE835326C (de) * 1942-02-19 1952-03-31 Wieland Werke Ag Dorn zum stetigen Giessen von Rohren und Hohlbloecken
DE1099700B (de) * 1953-12-03 1961-02-16 Ver Deutsche Metallwerke Ag Kuehleinrichtung unter Verwendung eines an seinem Ende geschlossenen Dornes und eines Kuehlmittelzuflussrohres innerhalb des Dornes zum Giessen von Hohlbloecken, insbesondere Rohren, in kontinuierlichen Giessverfahren

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE693644C (de) * 1937-01-01 1940-07-16 Hackethal Draht Und Kabel Werk Verfahren zur Herbeifuehrung eines gleichmaessigennsbesondere von Kabelmaenteln

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE835326C (de) * 1942-02-19 1952-03-31 Wieland Werke Ag Dorn zum stetigen Giessen von Rohren und Hohlbloecken
DE1099700B (de) * 1953-12-03 1961-02-16 Ver Deutsche Metallwerke Ag Kuehleinrichtung unter Verwendung eines an seinem Ende geschlossenen Dornes und eines Kuehlmittelzuflussrohres innerhalb des Dornes zum Giessen von Hohlbloecken, insbesondere Rohren, in kontinuierlichen Giessverfahren

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886996A (en) * 1973-03-13 1975-06-03 Aron Yakovlevich Tseitlin Device for producing internal cylindrical space in ingots
US4257472A (en) * 1979-07-30 1981-03-24 Concast Incorporated Continuous casting of hollow shapes
US4729422A (en) * 1982-01-13 1988-03-08 Vallourec Process and apparatus for the production of hollow bodies by continuously casting in a magnetic field
US4974660A (en) * 1982-01-13 1990-12-04 Vallourec Process and apparatus for the production of hollow bodies by continuously casting in a magnetic field

Also Published As

Publication number Publication date
FR2009059B1 (xx) 1973-12-21
FR2009059A1 (xx) 1970-01-30
GB1243579A (en) 1971-08-18
BE731799A (xx) 1969-10-01
AT286521B (de) 1970-12-10
SE348128B (xx) 1972-08-28

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