GB2128520A - A slag-scraping apparatus - Google Patents

Abstract

The apparatus includes a stationary scraper blade (8) and a movable blade (4) which moves by transmission of an arm (5) driven by drive rolls (6). The above-mentioned blades are articulated by means of an intermediate arm (10) to an arm (13) attached to the frame (25), and the intermediate arm (10) for its part is articulated by means of an arm (14), a crank arm (18) and a drive cylinder (15) to the turning arm (24) driven by a turning device (22). The blades can be lowered into a casting mold (1), and the movable blade (4) can be brought all the way up to the stationary blade (8) in order to collect slag from the molten metal surface. Thereafter the blades can be raised by joint operation of the cylinder (15) and the turning arm (24). Thereafter the movable blade (4) can be moved away from the stationary blade (8), at which time the slag between the blades falls into a container. <IMAGE>

Description

SPECIFICATION A slag-scraping apparatus The present invention relates to a slag-scraping apparatus which is of the type stated in the preamble of Claim 1. The invention relates in particular to an apparatus which functions fully automatically and thus makes possible operation in which human labor is required only for control tasks.

The slag-scraping apparatus used in the field are of many types. One extreme is a scraping apparatus which is operated solely by manpower, the device consisting of a scraping board operated by a person, and the other extreme consists of systems which operate more or less automatically and remove the slag from the surface of molten metal by means of various tools.

The latter-mentioned apparatus also include those in which the slag is scraped by means of two scrapers, one stationary and the other movable. One apparatus of this type is disclosed in SU Inventor's Certificate 472 753, in which two scraping blades pick up between them the slag from the surface of molten metal and are transferred by means of a bogie system moving on rails to another place, where they dump their load.

The said invention has a disadvantage in, for example, the fact that the structure is very complicated and heavy. Thus, one electric motor drive is required for moving the entire system, another one for moving the scrapers, and a third drive moves the bogie, moving on rails, which transfers the slag from one place to another. An additional disadvantage to be mentioned among those of the invention described in the publication is that electric-motor drives usually produce very sharp movements, for which reason spattering of molten metal and slag is common.

There are further known several different apparatus for removing slag as an overflow over the edge of the mold, in which case the scrapers are of a sweeping and linearly moving or, for example, rotating type. Problems associated with the spattering of the slag and molten metal and their transfer are typical of such apparatus, and for that reason they are not considered very practicable.

The object of.the present invention is to provide an apparatus by means of which slag can be removed from the surface of molten metal by using two scrapers, one of which is stationary and the other movable, an apparatus in which the removal of slag from between the scrapers occurs by controlled, even movements and along a path of movement suitable for the purpose. All of this is achieved using an apparatus the characteristics of which are given in the accompanying claims.

The invention is described below in greater detail with reference to the accompanying patent drawings, in which Figure 1 depicts a simplified side view of an apparatus according to the invention, before the scrapers are lowered into the slag layer in the mold, Figure 2 depicts a side view, similar to the previous one, of the apparatus at a time when the scrapers have been lowered to their scraping position, Figure 3 depicts further a similar side view of the same apparatus, with the scrapers raised to their dumping position, Figure 4 depicts the embodiment of the apparatus according to the invention as seen from a direction turned 900 in relation to Figures 1-3, and Figure 5 depicts the apparatus according to the invention as seen directly from above.

Figure 1 shows a casting mold 1 on the bottom of which there is molten metal 2 and on the surface of the metal a slag layer 3. In the figure in question the apparatus according to the invention is ready to be lowered into the mold, the lowering being carried out by means of a drive cylinder 1 5 in such a way that the distance between the cylinder attachment lugs 1 6 and 1 7 shortens. The scrapers are indicated by reference numerals 7, and the stationary one is attached to the apparatus by means of an arm 8 and a moving arm 4. The moving blade 7 is movable in such a way that, for example, a round arm 5 moves between rolls 6, driving power being introduced to the rolls 6 by means of, for example, pneumatic pressure.The system consisting of the scrapers and the drive device is articulated to an intermediate arm 10 by means of an articulation 9, in addition to which the system consisting of parts 4-8 is stabilized in a horizontal position by means of a parallelogram device, which is not shown in greater detail in the figure. The intermediate arm 10 is articulated to an arm 13 by means of an articulation 12, the arm 13 being attached to the frame structures of the apparatus.

As indicated above, the arm 14, by transmission of its articulations 11 and 1 9 and the arm 18, and driven by the drive cylinder 15, operates to lower and raise the scrapers into the mold and respectively out of the mold. Shortening of the drive cylinder means lowering of the system and lengthening of the drive cylinder respectively the raising of the system.

Another essential part of the drive mechanism of the scrapers consists of articulations 20 and 21, a turning arm 24 and a turning device 22, which is attached to a beam 23, which for its part is attached to the frame. Figure 1 shows, in addition, a frame beam 25, which is vertical, and transverse beams 26 and 27, which connect the frame beam 25 to another similar frame beam. Around the beam 26 there is a movable slide 28, and around the beam 27 a corresponding part 29. The operation of these devices is described in greater detail in connection with Figures 4 and 5.

Figure 2 depicts a representation similar to Figure 1 of the apparatus according to the invention, now lowered to its scraping position, the starting position of the moving scraper 7 being indicated by solid lines and its final position by dotted lines. The step illustrated by this figure is this simple, since in addition to the lowering into the mold there is only the transfer of the movable scraper substantially all the way to the stationary scraper.

Figure 3 shows a representation similar to those in Figures 1 and 2 of the apparatus according to the invention, but here with the scrapers in the dumping position. The move to the dumping position takes place as follows. First the cylinder 1 5 carries out the lengthening, whereby the arm 10 and the parts from it towards the scrapers rise somewhat from the mold 1, and thereafter the arm 24 makes an about 1 800 turn, at which time the arm 10 further rises more than 900 from its initial position, whereby the scrapers 7 move into the empty space between the arms 10 and 13, where the movable scraper is pushed apart from the stationary scraper, at which time the slag load held by them falls at a suitable place into a cart or similar device below.When the cart is full, the slag can be easily removed and exploited, or transported to a suitable place for storage or destruction.

Figure 4 shows the apparatus according to the invention as seen directly from the side of the apparatus. The overall structure of the apparatus is illustrated in this figure. Thus, the operating part of the apparatus is attached to two beams 26 and 27, which are between two vertical beams 25 and 30. The beams 26 and 27 are in an oblique position, their position corresponding to the position of the row formed by the casting molds, which can be seen at the lower edge of Figure 4.

In the apparatus according to the invention, the casting is carried out as continuous casting, in which case the mold row travels from the casting place to the slag-scraping place and from there on to a place where the hardened metal is removed from the mold. The direction of travel in Figure 4 is from the right to the left, i.e. the row of molds moves upwards. The operating part of the system, i.e. the actual slag-scraping apparatus, is attached to a so-called slide, which consists of a lower part 28 of the slide placed on top of the beam 26, and of guide parts 29 placed on top of beam 27; the latter could be called the small slide, for example.

The whole slide can be moved in the desired direction by means of the drive cylinder 33, which is articulated to the slide and the frame structures 34 of the device.

One essential part of the scraping apparatus according to the invention is a monitoring arm 32, which rests on top of the molds and falls from the edge of one mold onto another mold when the row of molds moves upwards. Such a monitoring arm 32 is used for giving the starting impulse to the scraping apparatus in such a way that the starting signal is given at every second fall, which is due to the fact that two molds at a time are scraped by means of the apparatus. For the sake of simplicity, the figure shows only the scraper blades 7, and the other structures of the scraper are not shown. Reference numeral 35 depicts a shaft about which the arm 24 depicted in Figures 1-3 turns, and reference numeral 37 depicts a handwheel by means of which the immersion depth of the scraper blades 7 into the slag in the molds and possibly molten metal can be regulated.

Figure 5 depicts the apparatus according to the invention as seen directly from above, those parts of the apparatus which have been described in connection with previous figures being indicated by the same reference numerals. The only addition to the reference numeral list is the parallelogram arm 36, which can be seen on the right-hand side of Figure 5 and by means of which the scraper blades with their arms 4, 8 and 5 are kept in substantially the same position throughout the duration of the raising.

The operation of the apparatus, according to the invention is as follows. As mentioned above, the starting signal is given by the monitoring lever 32 falling from the edge of one mold onto another.

When the monitoring lever falls from the edge of the mold, the movement of the slide is started by the drive cylinder 33, and the speeds of the slide and the mold row very soon even out to the same value. When the speeds have been synchronized, which is observed preferably by means of a sensor at the end of the monitoring lever 32, the blades 7 lower, in the open position, as shown in Figures 1 and 2, immerse somewhat into the molten metal in the mold, and thereafter they carry out the movement which is illustrated in Figure 2, i.e. the outer blade is moved by the rolls 6 all the way to the inner blade, at the same time scraping the slag which is on the surface of the molten metal to between the scraper blades.Thereafter, the raising mechanism is started, and the blades rise to the position depicted in Figure 3, at which time the separation of the blades from each other, starting somewhat before the extreme position, effects the dumping of the slag from between the blades into a cart or something similar below. The return movement begins immediately thereafter, and the sequence of events depicted in Figures 1-3 is repeated in the rhythm determined by the monitoring lever 32, the slide, driven by the drive cylinder 33, having to return backwards to be again synchronized with the travel speed of the next two molds in order to scrape off their slag by means of the apparatus according to the invention.

The apparatus according to the invention is operated preferably by means of compressed air, even though hydraulic operation is under certain conditions also fully usable and suitable. As mentioned before, the apparatus operates fully automatically and thus sets its own independent working rhythm, in which case manpower is required only for control tasks. In principle the apparatus according to the invention can be applied to any metal casting in which metal is cast into molds, as is done in the apparatus according to the invention, but one highly suitable metal for the purpose is zinc.

The drawings presented in order to illustrate the apparatus according to the invention show only the principle and not the detailed structure of the apparatus; the latter would tend only to confuse the description. Thus the apparatus, of course, includes various control means, safety means for cases of failure, means for dampening the movements of the slide at its extreme positions, various fasteners and support members for pipes and hoses, etc.

It is probably self-evident that the invention in question has been described in the form of only one preferred embodiment, any other embodiments within the protective scope of the claims also being usable. Thus the operation of the apparatus is not limited to use with a rising row of molds, but the apparatus works equally well when the molds move along a horizontal path, in which case the slide would also move on horizontal rails.

Likewise, it is clear that the operation of the apparatus is fully equal at any speed used for the mold row. Different casting conditions may require acceleration or deceleration of the casting process, in which case the scrapers also change their speed synchronically with the speed of the row of molds.

Claims (12)

1. An apparatus for scraping slag from the surface of molten metal in a mold by means of two scraper blades, of which one is stationary and the other movable, by lowering the blades into the mold and by bringing the blades together in order to collect the slag between them, the apparatus additionally having devices for raising/lowering the blades and for moving them to the dumping place, characterized in that the device for raising/lowering the blades is a drive cylinder and the device for moving the blades to the dumping place is a turning arm connected to the operation of the drive cylinder, the turning arm being intended to be operated by means of a turning device.

2. An apparatus according to Claim 1, characterized in that one end of the drive cylinder is connected by means of an articulation to an arm connected to the raising arm, and its other end is connected to a turning arm, which for its part is connected to the turning arm.

3. An apparatus according to Claim 2, characterized in that the arm is connected to the turning arm at a point between the cylinder attachment point and the turning-arm attachment point.

4. An apparatus according to Claim 1, characterized in that, in order to dump the slag from between the blades, the drive cylinder is designed to carry out the initial raising from the mold, whereafter, and possibly in part simultaneously, the turning arm is designed to carry out the combined raising and lateral transfer movement by turning about its shaft sufficiently far, usually up to 1800.

5. An apparatus according to any of the above claims, characterized in that the keeping of the blades in a horizontal position regardless of the movements and position of the arm is ensured by means of a parallelogram lever set.

6. An apparatus according to any of the above claims, characterized in that there are two pairs of blades, their purpose being to remove slag simultaneously from two molds.

7. An apparatus according to any of the above claims, characterized in that the purpose is to remove the slag from a moving row of molds, the apparatus following the movement of the molds during the work phase and returning to its initial position for the purpose of the movement of the next slag-removal phase, synchronically with the movement of the molds.

8. An apparatus according to any of the above claims, characterized in that the apparatus is installed so as to be supported by a slide fitted movably around the beams, in order to move, driven by the drive cylinder, in reciprocatingly in the longitudinal direction of the beams.

9. An apparatus according to any of the above claims, characterized in that the drive cylinders and the turning device, as well as the rolls which move the arm, are operated by compressed air.

10. An apparatus according to any of the above claims, characterized by a monitoring lever designed to give the apparatus an operating signal to start when the lever falls from the edge of one mold to the edge of another mold, and a scraping signal when the speed of the apparatus has reached the speed of travel of the molds.

11. An apparatus according to Claims 6 and 10, characterized in that the purpose of the monitoring lever is to give a starting signal at every second fall from the edge of one mold to the edge of another mold.

12. An apparatus for scraping slag substantially as hereinbefore described with reference to and as shown in the accompanying drawings.