Cooling structure for a metallurgical furnace

Abstract

A metallurgical vessel includes a cylindrical portion which is supported on a ring carrying a tilting spindle which is mounted for pivotal tilting movement of the vessel. The vessel includes a frustoconical mouth portion at its upper end which terminates in a mouth ring of reinforced construction. The construction includes a cooling arrangement for the mouth portion which comprises a plurality of groups of coils which are wound around the mouth portion and which are advantageously wound in the form of a multistart screw thread. Each group of coils includes an inlet and an outlet which is connected to a distributor through suitable valves. This distributor in turn is connected through a main distribution pipe which extends through an opening in the tilting ring and the tilting spindle and is connected to a source of fluid cooling medium through a rotary seal at the outer end of the tilting spindle.

Description

SUMMARY OF THE INVENTION

This invention relates, in general, to the construction of a metallurgical vessel, and in particular, to a new and useful steel mill converter having a wall which is partly hollow or which includes a plurality of cooling tubes therein which are connected to a common cooling fluid medium distributor.

Metallurgical vessels are subjected to natural stresses by the heat of their molten liquid content. The heat will flow through the masonry lining and reach a particular magnitude in some smelting processes. In the oxygen blast method the carbon oxide gas stemming from the refining operation leads to an after burning of the waste gases particularly inside the vessel due to an excess in the supply of oxygen. The melting of the lining and the costs of operation in which many changes occur permits a considerable amount of heat to enter the shell of the vessel so that the latter is stressed in some zones to a permanent deformation. The more the lining is worn, the more the temperature in the vessel shell will rise particularly during the period of the shocklike heat generation which takes place during the blasting period. Since the support for the lining of the vessel depends on the rigidity of the vessel shell, a cooled wall results in less stress and less tendency to warping.

Various measures for effecting the cooling of the vessel walls are known. First of all the vessel can be equipped with a double wall at least in the area of the mouth whereby the coolant is conducted through the tilting spindle itself. Double walls are not only hard to manufacture, they are very expensive. If despite the cooling, a conversion of the coolant into steam takes place due to local heating of the inside wall (referred to by a steel worker as a `red cheek`), the cooling effect will of groups of the cooling coils 8 are arranged in a group in special circuit form around the mouth cap 3. The inlets 10 emanate from a distributor 9 and the outlets (not shown) are connected to a similar distributor. Depending on the size of the vessel 5 each of the cooling coils 8 has about from 3 to 4 windings 11. Each circuit is laid out so that it has a winding of another circuit directly on each side thereof and this arrangement is achieved, for example, by laying the tubular conduits in a manner of a multistart screw thread. The distance 12 indicated in FIG. 2, between two adjacent winding 11 may be reduced by the interposition of additional cooling coils 8 to thereby increase the number of starts and the cooling output.

A feature of the construction is the formulation of the cooling coils which, in the embodiment illustrated, comprises a half tubular portion 13 which is closed by a shell portion 14 of the wall or shell 14 of the mouth cap 3. The half tubular portion may be joined by external welding seams to the wall 14 or by the use of special process by which a press fit is established continuously by electric induction heating which may be carried out in a protective atmosphere.

The distributor 9 is connected by a main supply line 15 which leads through an opening 16 in the carrying ring 6 and extends through the hollow tilting spindle 7 to a fixed coolant removal station (not shown). The main line 15 communicates with the fixed coolant station through a rotary seal (not shown) so that it does not interfere with the tilting movement of the vessel and its supporting spindle 7.

The distributor 9 is fastened to the reinforcing rings 18 and 19 which are carried on the cylindrical portion 4 of the vessel 5. Heat expansion between the carrying ring 6 and the vessel 5 are bridged by heat expansion compensator 17 which interconnects the portions of the main conduit 15 at this bridging location. Shutoff valves 20 are provided for each cooling coil circuit which consists of several windings 11. Accordingly, the implementation which is shown includes eight independent cooling coil circuits and a corresponding number of shutoff valves 20.

The principal principle of the use of independent cooling coils 8 arranged in groups or circuits can be applied to a multiplicity of designs. For a greater number of coils 11 with a higher number of starts of the screw threads, the main line 15 can be equipped, for instance, with additional distributors 9 all around the carrying ring 6. The invention is also applicable to other types of furnaces or vessels which have no round cross section. In addition, it is not necessary to maintain a helical-type circuit but, for example, the cooling coils 8 may take the course approximately in the direction of the longitudinal centerline of the vessel to provide, for example, curve-simulating garlands.

The pivot pin 7 is supported on a pivot bearing 21, which is mounted on a foundation 31. The pivot pin 7 is hollow, as indicated in the drawings and it carries a rotary packing 22 at its outer end. The rotary packing 22 comprises a tube 23, which is connected with the pivot pin 7 and which terminates in a flanged ring 24. The flanged ring 24 bears against a nonrotating flanged ring 25 of about the same size. A packing ring 26 is inserted between the two flanged rings 24 and rotatably mounted in the housing 28 and these two parts form the rotary packing. The connecting tube for the outflow of liquid is secured to the housing 28 and it opens into the main line 30, which is fed from lines in the interior of the foundations 31.

Claims

1. A metallurgical vessel construction, comprising a vessel having an exterior wall which is subjected to high temperatures, a plurality of groups of individual discrete coolant conduits positioned at a plurality of locations over said wall each defining a discrete fluid flow path for coolant extending to cover at least a widely distributed portion of a defined area of said wall for cooling said wall, a separate coolant supply means for each conduit, each of said groups including a plurality of separate coolant conduits and each conduit being connected respectively to a respective one of said coolant supply means, and said conduits of each of said groups being located alongside each other in each location so that there is always one of said separate discrete coolant conduits located adjacent each other so to that both cover and adjacent area areas of said wall, whereby at least one of said conduits will be effective in each groups even though another and valve means for enabling said coolant conduits to be individually shut off to terminate fluid flow therethrough, said conduits being arranged so that if any of said conduits is ruptured or disconnected from its coolant supply, any one of the other of said conduits through which fluid flow is maintained will provide a cooling effect which is widely distributed through the area of said wall to be cooled to compensate for the loss of conduits through which fluid flow is terminated.

2. A metallurgical vessel, according to claim 1, including a distributor for connecting said groups of said conduits to said fluid coolant supply, each of said groups of conduits being connected to said distributor.

3. A metallurgical vessel, according to claim 1, wherein said groups conduits are formed as continuous windings of with at least two separate conduits extending around said wall.

4. A metallurgical vessel, according to claim 2, wherein said groups of conduits comprise at least three separate conduits wound continuously around said wall, said wall being tubular and said conduits being in closely spaced side-by-side relationship.

5. A metallurgical vessel construction, comprising a vessel having an exterior wall, a plurality of groups of conduits defined over said wall with at least one of the conduits of one group being adjacent at least one of the conduits of another group, means for connecting said groups of conduits to a fluid coolant, said conduits comprising comprise a partial tubular wall portion located over said vessel, said vessel wall closing completing said partial tubular conduit.

6. A metallurgical vessel construction, comprising a vessel having an exterior wall, a plurality of groups of conduits defined over said wall with at least one of the conduits of one group being adjacent at least one of the conduits of another group, means for connecting said groups of conduits to a fluid coolant, said vessel including comprise a cylindrical wall portion and a frustoconical mouth cap portion, said groups of said conduits comprising coils distributed over said mouth cap portion.

7. A metallurgical vessel, comprising vessel construction according to claim 1, further comprising a cylindrical wall portion and an upper mouth cap portion, a supporting ring extending around said cylindrical portion and having a hollow tilt spindle adapted to be pivotally mounted for tilting said vessel with said support supporting ring a plurality of loops of conduits defined over said mouth cap portion wall with at least one of the conduits of one group being adjacent at least one of the conduits of another group, and means on said vessel for connecting said groups of said conduits to said fluid coolant.

8. A metallurgical vessel according to claim 6, 7, wherein said means for connecting said groups of conduits to a fluid coolant coolant supply comprises a conduit extending through said hollow tilt spindle.

9. A metallurgical vessel, according to claim 8, including a distributor carried on said vessel, each of said groups of conduits being separately connected to said distributor, a main conduit connected to said distributor, said valve means being connected between said distributor and each of said groups of conduits.

10. A metallurgical vessel, according to claim 9, wherein said main conduit extends through said hollow spindle and is adapted to be connected to a station fluid coolant supply said main conduit having an expansion portion therein located between said supporting ring and said vessel.

11. A metallurgical vessel, according to claim 10, including a rotary seal adjacent said hollow tilt spindle for connecting said main conduit to a fluid coolant.