GB2033863A

GB2033863A - Lifting and swivelling device for the cover of a furnace

Info

Publication number: GB2033863A
Application number: GB7934119A
Authority: GB
Original assignee: BBC Brown Boveri AG Switzerland; BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Switzerland; BBC Brown Boveri France SA
Priority date: 1978-10-04
Filing date: 1979-10-02
Publication date: 1980-05-29
Also published as: JPS5551284A; IT7925788A0; HU178186B; DE2845142A1; IT1123204B; GB2033863B; CH634645A5

Abstract

A lifting and swivelling device for the cover of a furnace, more particularly of an arc furnace, comprises a lifting and revolving column (1,1') supported in a guide arrangement (2,4) to be movable vertically and rotatable and provided with a swivelling mechanism (12) arranged tangentially, and further includes a bar (6) attached with parallel axis to the revolving column (1) and a fixed plate (7) extending at least in the swivelling area of the bar (6) and containing a bore (8) capable of receiving the bar (6). The swivelling mechanism may be connected to the bar (6) and preferably includes an hydraulic cylinder. The bore (8) permits the lowering of the revolving column (1), and thus of the superstructure, only in the position of the column for working of the furnace. <IMAGE>

Description

SPECIFICATION Lifting and swivelling device for the cover of a furnace The invention relates to a lifting and swivelling device for the cover of a furnace, and more particularly of an arc furnace, comprising a lifting and revolving column supported in a guide arrangement to be movable vertically and rotatable and provided with a swivelling mechanism arranged tangentially.

During the charging of a furnace all parts of the furnace located above the shell, namely the cover and the superstructure of the furnace, must be positioned to one side temporarily. This object can be achieved with different types of structures. One of these consists in the superstructure of the furnace with the furnace cover being swivelled around a round revolving column standing next to the shell of the furnace. The revolving column is simultaneously used for lifting the superstructure. The lifting of the superstructure is done almost exclusively by hydraulic means. The revolving column can be constructed either as a hydraulic piston, or a separate hydraulic cylinder can be installed underneath it.For the revolving movement e.g. either a toothed segment located on the revolving column can be used, or a double-acting hydraulic cylinder which, on the one hand, engages the stationary stand of the lifting and swivelling device for the cover and, on the other hand, is connected tangentially via a lever to the revolving column. In this structural solution the lifting and swivelling device for the cover is resting firmly on the foundation of the furnace and, accordingly must be capable of being engaged by the superstructure which during pouring off and slagging tilts along with the shell of the furnace, for swivelling and lifting and disengaged for tilting. For this purpose the upper end of the revolving column has a conical shape which matches the negatively conical shape in the receiving part of the superstructure and into which the revolving column can be moved.The easily produced conical shape guarantees that the revolving column will move safely into the receiving bore of the superstructure even with some slight eccentricity. This connection between the revolving column and the superstructure, however, could be of disadvantage if the raised superstructure or the furnace cover hanging on it were to come to rest on some body, accidentially located within its area, while being lowered in its swung-out position. This would endanger either the stability of the superstructure or bad jamming could occur in the guide mechanism for the column. It is also conceivable that the superstructure could be lowered unscheduled; this can be caused, for example, by inattentiveness or by a loss of pressure.

In accordance with this invention, there is provided a lifting and swivelling device for the cover of a furnace, comprising a lifting and revolving column supported in a guide arrangement to be movably vertically and rotatable and provided with a swivelling mechanism arranged tangentially, wherein at the revolving column a downward pointing bar is mounted with parallel axis, and a fixed structure is provided at least in the swivelling area of the bar and has, at the position of the location of the bar in the position of the column for working of the furnace, a bore or other recess for receiving the bar, said fixed structure preventing lowering of the column in other positions thereof. Any unintentional lowering of the superstructure of the furnace in its swung-out position is thus prevented.The bar is supported in the swung-out position on the fixed structure, preferably a plate, and the revolving column with the superstructure is thus held in the upper position. The bar can enter the bore in the fixed plate only in the working position and the superstructure can then sink down.

The structure is simplified if the swivelling mechanism is connected to the bar. For the bar, the already-present driving pin of the swivelling mechanism can be used, which is thus only extending by the length of the upstroke of the revolving column. Advantageously, the swivelling mechanism includes a swivelling drive cylinder. The swivelling mechanism may be arranged on the fixed structure so that no additional support parts need to be used for mounting the swivelling mechanism. Preferably, a stop is provided to secure the position of the swivelling mechanism in the vertical direction, because otherwise it could be carried along by friction from its correct, that is mostly horizontal, position during the vertical movement of the bar.This inclined position could cause an undesired rotation ofthe revolving column and ofthe superstructure.

The bottom end of the bar may be provided with a support piece of greater cross-section than that of the bar, to secure the correct position of the swivelling mechanism also during swivelling movement and in the swung-out position. Since the horizontal cross-section of the support piece is greater than that of the bar, the bar is protected from mechanical damage during its movement in the bore or other recess in the fixed plate or other structure.

The surface of the bar remains smooth and the mutual movement of the bar and of the pivot head of the swivelling mechanism is thus facilitated. The fixed plate may comprise at least one guide element, preferably two guide plates arranged radially of the column, to ensure guidance of the support piece also underneath the fixed plate so that the smooth surface of the bar does not touch the wall of the bore in the fixed plate and cannot be damaged.

An embodiment ofthis invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a front view in partial section of an illustrative embodiment of a lifting and swivelling device for a cover according to the invention, Figure 2 shows the plan view of the device according to Figure 1 and Figure 3 shows the section Ill-Ill from Figure 1.

According to Figure 1, a revolving column 1 is provided with a conical end 1'. A cylinder 2 is connected to a base plate 3 and contains guides 4 of the revolving column 1. To the revolving column 1 a bar 6 with parallel axis and equipped with a head 6' is connected by means of mounting plates 5. Afixed plate 7, arranged horizontally, with a bore 8 is attached to the cylinder 2. The lower end of the bar 6 is provided with a support piece 15. The fixed plate 7 is supported by two guide plates 16.

In Figures 2 and 3, identical parts are given the same reference numbers as in Figure 1. According to Figure 2, a swivelling cylinder 9 is attached to the fixed plate 7 by means of a support 10. A piston rod 11 of the swivelling cylinder 9 is provided with a pivot head 12 which encompasses the bar 6 with play (see also Figure 1). A stop 13 for securing the height position of the pivot head 12 is only shown simplified. In the lower part of the cylinder 2 there is a space 14forthe lifting drive of the revolving column 1.

Figure 3 shows the section Ill-Ill from Figure 1. Two guide plates 16 are mounted in vertical planes radially with respect to the cylinder 2. Their surfaces are tangent to the bore 8 so that they can serve as guide surfaces for the support piece 15.

All structural features which are not directly necessary for understanding the invention such as the superstructure of the furnace and the lifting drive, have been left out of the drawing.

The revolving column 1 is shown in its upper position so that the bar 6 is located above the fixed plate 7 and is not blocked in the bore 8. The arc-shaped arrow drawn in Figure 2 shows the movement of the bar 6 with its head 6' from the operating position represented into the swung-out position. In Figure 2 the bore 8 is located underneath the head 6' of the bar 6.

Claims

1. A lifting and swivelling device for the cover of a furnace, comprising a lifting and revolving column supported in a guide arrangement to be movable vertically and rotatable and provided with a swivelling mechanism arranged tangentially, wherein at the revolving column a downward pointing bar is mounted with parallel axis, and a fixed structure is provided at least in the swivelling area of the bar and has, at the position of the location of the bar in the position of the column for working of the furnace, a bore or other recess for receiving the bar, said fixed structure preventing lowering of the column in other positions thereof.

2. A device according to claim 1, wherein the bar is connected to the swivelling mechanism.

3. A device according to claim 1 or 2, wherein the swivelling mechanism includes a swivelling drive cylinder.

4. A device according to claim 1,2 or 3, wherein the swiveiling mechanism is arranged on the fixed structure.

5. A device according to any preceding claim, further comprising a stop for securing the position of the swivelling mechanism in the vertical direction.

6. A device according to any preceding claim, wherein the bottom end of the bar is provided with a support piece the horizontal cross-section of which is greater than that of the bar.

7. A device according to claim 6, wherein the fixed structure comprises a fixed plate below which at least one guide element is mounted for the guidance of the support piece.

8. A device according to claim 7, wherein two guide plates are provided to guide the support piece, said guide plates being arranged radially with respect to the column.

9. A device according to any one of claims 1 to 6, wherein the fixed structure comprises a fixed plate.

10. A lifting and swivelling device for the cover of a furnace, substantially as herein described with reference to the accompanying drawings.

11. A furnace comprising a lifting and swivelling device for its cover, which device is as claimed in any preceding claim.