US3588274A - Metallurgical manipulator - Google Patents

Abstract

THIS INVENTION RELATES TO A METALLURGICAL MANIPULATOR FOR ACHIEVING MOTION IN MOLTEN METALS AND/OR SLAG. THE MANIPULATOR PREFERRABLY CONSISTS OF TWO SHAFTS INSULATED AGAINST HEAT BY A CERAMIC COATING, THE SHAFTS BEING DRIVEN AT ONE END BY A HYDRAULIC MOTOR AND AT THE OTHER END BEING PROVIDED WITH CERAMIC BLADES COORDINATED PROPELLER-SHAPED OR PARALLEL WITH THE SHAFT, ROTATING TOWARDS EACH OTHER.

Description

United States Patent [72] Inventor Sven Erik Malte Norlindh Smedjebacken, Sweden [2]] Appl. No. 787,467 [22] Filed Dec. 27, 1968 [45] Patented June 28, 1971 [73] Assignee AB Inva Smedjebacken, Sweden [32] Priority Dec. 29, 1967 [3 3 Sweden 18018/67 [54] METALLURGICAL MANIPULATOR 2 Claims, 7 Drawing Figs.

[52] US. Cl. 416/63, 259/lO4,4l6/l2l, 416/241 [51] lnt.Cl FOld 5/28 [50] Field of Search 416/241,

[56] References Cited UNITED STATES PATENTS 2,8ll,339 10/1957 Osborne etal 4l6/24i(X) FOREIGN PATENTS 251,513 5/l926 Great Britain 416/63 Primary Examiner- Everette A. Powell, Jr. Attorney-Pierce, Scheffler and Parker ABSTRACT: This invention relates to a metallurgical manipulator for achieving motion in molten metals and/or slag. The manipulator preferrably consists of two shafts insulated against heat by a ceramic coating, the shafts being driven at one end by a hydraulic motor and at the other end being provided with ceramic blades coordinated propeller-shaped or parallel with the shaft, rotating towards each other.

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MM. k 17- 1/ METALLURGICAL MANIPULATOR In metallurgical processes it has until now been difficult to make sufficiently simple and effective devices to achieve desirable movements within and between the different components.

The main object of this invention is to produce a simple and effective device to achieve motion in molten metals and/or slag. A further object is to produce a device, by which a mo.- tion is achieved in molten metals and/or slag in furnaces or ladles of different types. It can thus be introduced into the furnace or the ladle from the top or the side and be adapted to the majority of the anticipated needs.

The metallurgical manipulator according to the present invention is characterized in that it consists of at least one shaft insulated against heat by means of a ceramic coating, the shaft at one end being driven by, for example, a hydraulic motor and at the other end being provided with ceramic blades either propeller-shaped or parallel with the shaft. The shaft is mounted at its driven end in a bearing housing connected to a lever arm and a hydraulic cylinder, hence the manipulator is adjustable to different angles of elevation. In accordance with a preferred embodiment the manipulator consists of two shafts, motors and blades arranged side by side. At least one of the bearing housings is made to swivel in relation to the other by means of a hydraulic cylinder, whereby the distance between the blades and the angle between the shafts may be varied. Immersed in molten metal these combined manipulations produce circulation within the metallurgical container or, if the blades are only immersed in the slag, the slag is discharged from the metallurgical container or, if the blades are immersed in some intermediate position, they produce a mixture of slag and/or added slag formers and/or alloying elements and the molten metal, while at the same time the components are made to circulate within the metallurgical container.

It is suitable to attach a manipulator unit to a fork lift truck, the manipulator unit consisting of two manipulator shafts with blades, driving devices and adjustment devices for placing one of the manipulator shafts at a side angle in relation to the other and a quick-coupling device for attaching the manipulator unit to the fork lift truck, the fork lift truck transporting, supporting and adjusting the height, angle of elevation and side angle of the manipulator shafts.

The present invention is illustrated in greater detail in the following, reference being made to the attached drawings, where:

FIG. 1 is a cross section along line I-I in FIG. 2 through part of an open hearth furnace with the metallurgical manipulator immersed in the slag layer for slag removal.

FIG. 2 shows an angular horizontal section along line II-II in FIG. 1;

FIG. 3 shows a longitudinal section through a manipulator rod with propeller-shaped blades.

FIG. 4 shows a side view of a four-blade propeller.

FIG. 5 shows a view from the bottom of the propeller in accordance with line V-V in FIG. 3.

FIG. 6 shows a side view of the lower part of themanipulator rod with 2 blades parallel with the manipulator shaft.

FIG. 7 shows a view in accordance with line VII-VII in FIG. 6.

In FIG. 1, 1 indicates the molten metal and 2 a slag layer in open hearth furnace II with vault l2. Manipulator rods 3 have been introduced through hole IS in furnace door 14 through opening I3 into slag layer 2.

The manipulator rods 3 are mounted in bearing housing 16 and driven by variable-speed hydraulic motors 17 with a reversible motion and may be set to the desired angle of elevation by means of pivot bearing I9, pivot arm 18 and cylinder 20. The manipulator with its drive and setting equipment is mounted on plate 21, suitably quick-coupled to a fork lift truck 22.

FIG. 2 shows a top view of the manipulator with pivot point 23 and cylinder 24 for setting the distance between the manipulator blades and adjusting the lateral position. The

pivot cylinder is not shown in FIG. I. In addition the dotted lines in FIG 2 shows a groove or pipe for the supply of slag formers and/or alloying elements which may be feed in pneumatically or by means of a vibrator.

FIG. 3 shows a section through the manipulator rod, where propeller boss 32 and propeller blades 31 of ceramic material are fixed with screws 36 and a head 34 with spline 35 to the center rod 37 protected against the heat by ceramic coating 38 and bottom plug 33. Center rod 37 as well as splined head 34 and screws 36 may slidably be made of high-temperature alloy since one is unwilling to resort to water cooling. Of course, the propeller boss may be made with some other type of fixing, for example, a taper thread at the end of center rod 37.

The center rod is made for quick-coupling with supported shaft 39, for example, with a taper pin 40.

The 4- blade propeller 31, 32 is shown in greater detail in FIGS. 4 and 5. The manipulator blades may even by shaped in some other suitable way, for example as in FIGS. 6 and 7, which may be suitable if the manipulator is to be immersed approximately perpendicularly in a ladle or a highor low frequency furnace or through an opening in the vault of a metallurgical furnace.

In FIG. 1 the manipulator has been shown immersed only in slag layer 2 in a rotational direction 27, slag 2 being discharged over the door threshold according to arrow 28. The propeller pitch, direction of rotation and rightor lefthanded propeller must be chosen so as to suit the characteristics of the slag.

The dotted position of the manipulator shown in FIG. l with the propeller rotating in slag layer 2 as well as in molten metal 1, produces circulation in slag layer 2 as well as in molten metal 1 in accordance with arrows 30 in FIG. 2, while at the same time slag layer 2 is whipped into the molten metal 1 rendering the metallurgical reactions less difficult. If the manipulator is immersed still deeper the slag is only slightly affected and one gets approximately the same effect produced by an inductive mixer.

If the old slag 2 is removed in accordance with FIG. I new slag and/or alloying elements may be introduced according to arrow 26 via vibration pipe 25, whipped into molten metal I and circulated and dispersed all through the metal bath. Thereafter the slag removal process may be repeated. The vibration pipe need only be pushed in for a short time and is then cooled from the inside by the additions.

With this device desulfurization may be carried out in a small container, through which the pig iron is passing from the tap hole of a blast furnace, Desulfurization at the pig iron stage may even be carried out in a ladle or a pig iron mixer.

Desulfurization, dephosphorization, alloying and deoxidation may be carried out at the steel stage in an open furnace and in a ladle thanks to the thorough mixing of the steel and slag by means of a manipulator.

In an open hearth furnace one may besides produce circulation in the slag and metal bath and in an electric arc furnace the manipulator can replace the electric induction coils.

Since the manipulator allows for the intensive mixing of the slag and the metal bath while at the same time the components are being circulated, the time for finishing the melt is shortened. Thanks to the simple and effective removal of the slag it may be changed several times and a product having a higher quality may be achieved.

By choosing the best direction of rotation and suitable number of revolutions of the manipulator the most effective conditions for the different work moments may be achieved.

One may even quickly hook a second manipulator onto the fork lift truck. The movements required for the manipulator are an adjustment of the height, angle of inclination and distance between the blades of the manipulator rods and the lateral adjustment. These adjustments may be made by the fork lift truck or some. other control device and by the manipulator unit itself. If the fork lift truck has a sufficient tilting motion, tilting cylinder 20 and pivot point 19 will not be required. Furthermore one of the tilting cylinders 24 may be discharged since normal fork lift trucks have good lateral adjustment possibilities.

When removing slag from the furnace it is very important that the manipulator should be equipped with two cooperating rods with blades which rotate in opposite directions in order to force the slag to pass between the blades of both rods and discharge the slag in a defined direction through the furnace door. The principle implying two cooperating manipulator rods and blades is also of value when additions and slag formers are added, in that these are forced in between the blades of both rods and down into the metal bath so that the reactions occur quickly and the additions are effectively exploited for the desired reactions. The conditions are the same when the slag bath is circulated and thus forced to pass between the blades of both manipulator rods for renewed reaction.

I claim:

1. A metallurgical stirring device for achieving motion in molten metal or slag, which consists essentially in the following combination;

a mobile support means;

a pair of ehocks mounted on said support means, one of said ehocks being directable in different direction than the other;

a bearing member in each of said chocks,

each said bearing housing a shaft;

each bearing having connected to one end thereof an electric motor driving means;

each shaft being coated, over that portion thereof remote from said driving means, with a protective coating of ceramic material thereabout;

each shaft carrying, at that end thereof remote from said driving means, a ceramic blade, the blades rotating toward each other and coordinated; and

means including a hydraulic cylinder for varying the distance between the blades as well as the angle between the shafts,

2. A metallurgical stirring device according to claim 1, in which the chocks are controlled by means ofa pivot arm and a cylinder, in such a way that the shafts of the stirring device are adjustable to various angles of deviation,

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