US3000621A

US3000621A - Tiltable crucible or converter for refining crude iron

Info

Publication number: US3000621A
Application number: US797507A
Authority: US
Inventors: Puxkandl Peter
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG; Voest AG
Priority date: 1958-03-12
Filing date: 1959-03-05
Publication date: 1961-09-19
Anticipated expiration: 1978-09-19

Description

p 1961 P. PUXKANDL 3,000,621

TILTABLE CRUCIBLE OR CONVERTER FOR REF INING CRUDE IRON Filed March 5, 1959 H \i k I 5b F/6.1

7b 7a 7 6a 6b INVENTOR.

P ETER PUXKAN DL [0L4 ATTo/eNeYs 3,000,621 v TILTABLE CRUCIBLE OR CONVERTER FOR REFINING CRUDE [RON Peter Puxkandl, Linz, Austria, assignor to Vereinigte Osterreichische Eisenund Stahlwerke Aktieugesellschaft, Linz, Austria, an Austrian company Filed Mar. 5, 1959, Ser. No. 797,507 Claims prio 'ty, application Austria Mar. 12, 1958 4 Claims. (Cl. 266-39) Tiltable crucibles or converters for refining crude iron consist of a cylindrical or pear-shaped vessel which is provided with a refractory lining and the bottom part of which may be integral with or removable from the shell part. The shell of such crucible is surrounded approximately on the level of the center: of gravity by a supporting trunnion ring, which is rigidly connected to two trunnions. By means of electric or hydraulic drive means connected to the trunnions the crucible must be capable of being tilted from an approximately vertical blowing position to an inverted position until it is completely emptied, and of being subsequently re-erected. The trunnion ring has the function of reliably holding the crucible in all positions and of transmitting to the crucible the forces which are exerted by the drive means. The holding and guiding of the crucible must be effected in such a manner that expansion due to heat or refractory pressure is possible from the center of the crucible in four directions, preferably in the axis of the trunnions and at right angles thereto. This requirement can be complied with by the provision of so-called claws, consisting of short angle brackets, one flange of which is rigidly connected to the crucible wall, e.g., by riveting, whereas the other flange protruding from the outside wall of the crucible bears on the trunnion ring. The protruding flange portion has a degree of freedom of movement in a centrifugal direction from the axis of the crucible. For this reason the trunnion ring must surround the Wall of the crucible with a clearance to permit of an expansion. The guides of the claws in the direction of the trunnions have also the function of preventing a slipping of the crucible in any desired tilted position.

Four to eight pairs of claws spaced around the periphery of the crucible have previously been used for holding the crucibles and the supporting trunnion ring was engaged without play by one protruding flange portion of each pair on the top and by the other protruding flange portion on the 'bottom. This arrangement involved difliculties, however, because the support of the crucible in any other than the horizontal position became one to five times statically indeterminate. This prevented an exact determination of the stresses. Because .safety considerations require the dimensions of the trunnion rings to be calculated for the least favorable stress cases, the trunnion rings become very heavy and uneconomical.

It is an object of the present invention to eliminate these difficulties and to provide an improved mounting of the crucibles on the trunnion ring to achieve a substantial reduction in weight and in material and processing costs.

The crucible or converter according to the invention comprises a supporting trunnion ring extending around the shell of the crucible and comprises two trunnions, the ring being mounted between the protruding flanges of pairs of claws spaced around the periphery of the crucible, and is characterized according to the invention in that only three pairs of claws are provided, with which the crucible firmly engages the top and bottom of the trunnion ring, two of said pairs of claws extending diametrically opposite each other in the plane of the trunnion axis of the carrying ring and the third pair of claws Patented Sept. I9, 1961 extending in another direction, preferably at right angles to the trunnion axis.

of the pairs of claws disposed in the trunnion plane. In any tilted position outside the vertical position the crucible rests with the upper claws on three bearing points whereas the lower claws forrn guides. The same conditions exist beyond the horizontal tilted position when those flange portions which were previously the lower guide portions have become carrying bearing portions and the previously carrying upper portions have become guide portions. Thus, a three-point support, which permits of an easy statical analysis, is ensured in any tilted position and the material expenditure required for the trunnion ring is much reduced.

To guide the crucible in the case of heat expansion or deformation, the trunnion ring is provided according to the invention on both sides of each claw with two guide rails, between which each protruding flange is slidable. In a preferred embodiment of the invention a guide is provided not only in the direction of the three pairs of claws but also in a fourth direction, suitably opposite to the third pair of claws, in a plane which extends at right angles to the trunnion plane. In this case a fourth pair of claws with guide rails is arranged at this point and the upper and lower flange portions of this pair of claws are slightly spaced from the trunnion ring to permit of a free upward and downward play thereof. The height of the guide rails exceeds this play so that the fourth pair of claws, while it cannot take up hearing forces, cooperates with the rails to guide the crucible like the other unstressed portions of the three other pairs of claws in the case of heat expansion or deformation.

The invention is explained more in detail in the drawing. FIG. 1 is a top plan view and FIG. 2 a side view showing the trunnion ring and the claws. FIG. 3 is a diagrammatic representation of the degrees of freedom of a crucible which is provided with the mounting according to the invention.

The trunnion ring 2 surrounding the crucible shell 1 is rigidly connected to the two trunnions 3. The converter wall carries the pairs of

claws

4 and 5 in the plane of the trunnions and the pairs of

claws

6 and 7 in a plane which extends at right angles thereto. Each pair of claws consists of upper and lower angle brackets. One flange of each bracket (4a, 5a, 6a, 7a) is firmly connected to the crucible wall, e.g., by riveting, and the other flange of each bracket (4b, 5b, 6b, 7b) protrudes at right angles from the crucible wall. The trunnion ring is mounted between the protruding flanges of the pairs of

claws

4, 5, 6 so that these flanges firmly engage the top and bottom of the trunnion ring. On the other hand, a clearance 8 is provided between'the protruding flanges 7b of the fourth pair of claws and the top and bottom of the trunnion ring so that the trunnion ring cannot take up bearing forces at this point. The support of the crucible is provided by means of the other three pairs of

claws

4, 5, 6. In the vertical position only the

upper claws

4b and 5b and in any tilted position as far as to the horizontal position only the

upper claws

4b, 5b and 6b carry load. This ensures a statically favourable three-point support in any position.

On both sides of each protruding flange (4b, Sb, 6!; and 7b) the trunnion ring is provided with guide rails 10, between which each protruding flange is slidable. As is apparent from FIG. 2, such guide rails are also provided for the unstressed fourth pair of claws 7; the clearance 8 is less than the height of the rails 10 so that this pair of claws has approximately the same effect with respect to the guidance of the crucible in the case of heat expansion as the load-carrying other pairs of claws.

FIG. 3 shows the degrees of freedom of the statically determined three-point support of the'crucible according to the invention. At

points

4, 5, 6 corresponding to the pairs of

claws

4, 5, 6 the crucible has only one degree of freedom of movement, in the trunnion plane and at" right angles thereto, so that it is capable of free 'eXpan sion. In point 7 of the unstressed pair of claws a de' gree of freedom of movement in the direction of the crucible axis exists in addition to the degree of freedom of expansion at right angles to the trunnion plane so that tilting forces will not be transmitted at this point.

What I claim is:

1. A tiltable crucible for refining crude iron compri's ing a crucible shell of substantially circular cross-section, a ring surrounding said shell, diametrically spaced trunnions extending outwardly from said ring, three pairs of angularly spaced-apart claws on said shell slidably receiving said ring and supporting said shell on said ring, two pairs of said claws being arranged diametrically opposite each other on a diameter substantially coinciding with the axis of said trunnions and the third pair of claws being interposed between said two pairs of claws to pro vide for three point support of said shell on said ring.

2. The tiltable crucible set forth in claim 1 in which the said third pair of claws extends at substantially a Iright angle to the trunnion axis.

3. A tiltable crucible for refining crude iron comprising a crucible shell of substantially circular cross-section, three pairs of flanges extending outwardly from and spaced around the periphery of the said shell, a ring ex tending around "said shell having upper and lower sur faces slidably engaging said pairs of flanges, diametri' cally spaced, coaxial trunnions extending outwardly from said ring, two pairs of said flanges being arranged dia' metrically opposite each other on a diameter substantially coinciding with the axis of said trunnions and the third pair of flanges extending at about a right angle to the trunnion axis to provide three point support for said shell, pairs of guide rails extending from said ring on opposite sides of at least one flange of each pair of flanges and in slidable engagement therewith to position said shell in said ring.

4. The tiltable crucible set forth in claim 3 comprising a fourth pair of flanges opposite said third pair of flanges on said shell in right angular relation to the trunnion axis, said fourth pair of flanges being spaced from the upper and lower surfaces of said ring so that they do not support said shell and guide rails on said shell 'slidably engaging the sides of said fourth pair'of flanges.

References Cited in the file of this patent UNITED STATES PATENTS 986,534 Woods Mar. 14, 1911 1,126,687 Beebe Feb. 2, 1915 2,301,880 Johnston Nov. 10, 1942 2,823,028 MacGregor et a1 Feb. 11, 1958