FR2513924A1 - DECALAMINATION DEVICE FOR METALLURGICAL PRODUCTS - Google Patents

Abstract

SCALAMINATION DEVICE FOR METALLURGIC PRODUCTS IN SCREENING. THE DEVICE IS CHARACTERIZED IN THAT IT CONTAINS: -A METAL BOX 1 DIVIDED INTO THREE IN A WAY TO BE DEFINED, IN THE DIRECTION OF MOVING OF THE PRODUCT 2, A FIRST SUCTION CHAMBER 3, A SANDING CHAMBER 4 AND A SECOND CHAMBER SUCTION 5, WALLS 6, 6, 7 AND 7 OF SAID CHAMBERS WITH OPENINGS 8, 9, 10 AND 11 WHICH ARE IN RELATION TO ONE OF THE OTHERS SO AS TO PROVIDE A PASSAGE FOR THE PRODUCT 2; TWO SAND INJECTION NOZZLES 12 AND 13 BY A GAS, FOR EXAMPLE COMPRESSED AIR, LOCATED AT THE UPPER AND LOWER PART OF THE SANDBLASTING CHAMBER 4 AND ORIENTED RESPECTIVELY TOWARDS THE UPPER SIDE AND THE LOWER SIDE OF THE PRODUCT 2; -OF SUCTION DUCTS 17, 18, 19 AND 20 CONNECTED TO SUCTION CHAMBERS 3 AND 5; -A CONTAINER 16 COMMUNICATING WITH THE LOWER PART OF THE SANDING CHAMBER 4, THIS CONTAINER IS INTENDED FOR THE RECOVERY OF SAND AND CALAMINE, AND -MEANS TO PREVENT THE SAND FROM PASSING FROM THE SUCTION CHAMBERS 3 AND 5 TO L 'EXTERIOR OF THE HOUSING 1.

Description

DECALAMINATION DEVICE FOR METALLURGICAL PRODUCTS

  The present invention relates to a device for descaling scroll metallurgical products, intended more particularly for the descaling of products at high temperature, just before or during

their rolling.

  It is known that, in order to manufacture steel sheets, steel slabs are subjected to rolling after having previously heated them to a temperature of about 12 000 ° C. During the reheating operation, there is formation of steel slabs. a layer of calamine on the slabs which causes surface defects in the sheets subsequently obtained.

  therefore obliged to decalcify the slabs just before rolling.

  Currently, this operation is carried out by hydraulic descaling

  by watering the slabs by jets of water at high pressure.

  This hydraulic descaling has the disadvantage of causing a decrease in the average temperature of the slabs of about 200 C, a decrease that is offset by heating the slabs at the start.

  more importantly Hydraulic descaling is therefore not very

  from the point of view of heat balance.

  This drop in temperature is all the more important as the

  rolling speed is low And in this case, the hydraulic descaling

lique is no longer usable.

  The object of the invention is precisely to solve the problems

peeled above.

  For this purpose, the subject of the invention is a device for descaling

  metallurgical products in scrolling which comprises: a metal box divided in three so as to define, in the direction of movement of the product, a first suction chamber, a blast chamber and a second suction chamber, the walls of said chambers having openings facing each other so as to provide a passage for the product, two sand injection nozzles by a gas, for example compressed air, placed at the top and the part lower of the blast chamber and oriented respectively towards the upper face and the lower face of the product, suction ducts connected to the suction chambers,

  a container communicating with the lower part of the chamber

  sandblaster, said container being intended for the recovery of sand 39 and calamine, and

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  means for preventing sand from passing vacuum chambers

outside the case.

  According to one embodiment, the means for preventing the sand from

  to pass suction chambers outside the casing are

  killed by two pairs of metal brushes attached to the outer wall.

  have suction chambers, the brushes of each pair being

  in order to be in contact respectively with the upper surface

and the underside of the product.

  The device according to the invention may further comprise means for preventing the sand from passing from the blast chamber to the second suction chamber. These means may be, for example, constituted by two metal brushes fixed on the inner wall.

  the second suction chamber and placed so as to be in contact with

  tact respectively with the upper face and the lower face of the

product.

  The device according to the invention may also comprise, in the

  inside the sandblasting chamber, means to prevent the sand from

  These means can be constituted

  killed by two pairs of metal plates, the plates of each pair being disposed near the walls of the blast chamber and on either side of the product, said plates being arranged so as to

  be in contact, by one of their side, respectively with the upper face

  upper and lower side of the product.

  According to an alternative embodiment, each of the injection nozzles is mounted on a reciprocating mechanism perpendicular to the direction of

  scrolling of the product so that the sand jet sweeps

  the top and bottom of the product.

  Other features and advantages of the invention will be better

  understood by reading the following description, made with reference to

  In the attached figures in which: Figure 1 shows a sectional view of an embodiment of the descaling device, Figures 2-A and 2-B respectively show a sectional view and a side section of the chamber of sandblasting, in the case where the device comprises a system for scanning the product by the sand jet. As can be seen in FIG. 1, the descaling device comprises a metal casing 1 which is successively divided into three chambers with respect to the direction of travel (represented by an arrow) of the metal product 2, namely, a first chamber suction 3,

  a blast chamber 4 and a second suction chamber 5

  Kings, external 6 and 6 'and internal 7 and 7', have openings 8, 9, 10 and 11 facing each other so as to provide a passage of the product 2 through the casing 1.

  Two sand injection nozzles 12 and 13 are arranged at the

  upper and lower part of the blast chamber 4 and oriented respectively to the upper face and the lower face

of the product 2.

  The injection nozzles 12 and 13 are connected to ducts 14 and 15 which are in turn connected to sources of sand and air

  compressed (not shown in Figure 1).

  The sanding chamber 4 is in communication at its lower part.

  with a container 16 for the recovery of sand and

calamine detached from product 2.

  As shown in FIG. 1, the suction chambers 3 and 5

  connected to their upper and lower parts to con-

  suction ducts 17, 18, 19 and 20 The ducts 17, 18, 19, and 20 are connected in turn to a suction system (not shown in FIG.

figure 1).

  The external walls 6 and 6 'of the suction chambers comprise metal brushes 21, 21' and 22, 22 '. The density of these brushes

  metal is such that sand can not pass outside the bowl.

  Tier 1, but that compressed air is likely to pass

  in a small quantity so as to create a pressure loss of the

  pressure in the suction chambers 3 and 5.

  According to a preferred embodiment of the invention, a pair of metal brushes 23 and 23 'is fixed to the inner wall 7' of the second suction chamber 5 Each of the brushes 23 and 23 'is in contact respectively with the face upper and lower face of the

product 2.

  Two pairs of metal plates or flaps 24, 24 'and 25, 25' are arranged in the blast chamber 4 The flaps 24, 24 'and 25' are arranged so as to touch respectively the upper and lower faces of the product 2 and therefore to be able to prevent the sand

  to pass in the suction chambers 3 and 5.

  Figures 2-A and 2-B show a system according to which the jet

  sand sweeps the entire width of the product.

  As can be seen in FIG. 2-A, the injection nozzle 12 is mounted on a support 26 which comprises at one of its ends a screw 27 and at the other end a hole 28. two cylinders 29 and 31 are arranged parallel to each other, through the chamber of

  sandblasting 4, above and perpendicular to the passage of the product 2.

  The cylinder 29 is rested on bearings 31 and 31 'which are arranged respectively in the side walls 32 and 32' of the chamber

  The cylinder 29 is connected to a motor 33 by means of

  The motor 33 is rotated alternately.

  As can be seen in FIG. 2-A, the central portion 35 of the cylinder 29

  is threaded; the screw 27 of the support is engaged on this part 35.

  The cylinder 3 L is fixed at its ends to the side walls 32 and 32 'of the blast chamber The support 26 of the injection nozzle

  is slidably mounted on the cylinder 30, through the hole 28.

  As can be seen in FIG. 2-B, the injection nozzle 12 is connected to the suction duct 14 via a duct

  flexible 36 which allows the movement of its support 26.

  The operation of the device according to the invention is as follows.

  The metal product passes through the openings 8, 9, 10 and 11 through the chambers 3, 4, and 5. In the sanding chamber 4, the sand

  is injected by compressed air by means of the injection nozzles 12 and 13.

  Thanks to the mechanical shock thus caused, the calamine cracks and

stain the sides of the product 2.

  The flaps 24, 24 ', and 25, 25' prevent injected sand and moisture.

  detached laminate of the product 2 to pass into the suction chambers 3

  and 5; sand and calamine torgbent by gravity in the container 16.

  The suction chambers 3 and 5 are emptied by suction, which

  avoids any pollution of the environment by sand and dust.

  The metal brushes 21, 21 'and 22, 22', closing off the interstices between the openings 8 and 11 and the product 2, create the pressure drop in the suction chambers 3 and 5, which facilitates the suction of sand and dust Metal brushes 22 and

  22 'also have the function of cleaning the faces of the product 2.

  The metallic brushes 23 and 23 'function on the one hand to prevent the sand from passing into the second suction chamber 5, on the other hand to scrape the pieces of calamine stuck on the faces of the

  product 2 and to keep it clean.

  When the running speed of the product 2 is very low, it is possible to use the system according to which the sand jet sweeps the width

39 of the product 2.

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  In the scanning system shown in FIGS. 2-A and 2-B, the alternating rotation of the motor 33 is transmitted through the gearbox 34 to the cylinder 29. This alternating rotation of the cylinder 29 is transformed into a linear movement of sliding back and forth on the cylinder 30 It is possible to adjust the speed of the back and forth movement of the support 26 so as to be able to scan the entire width of the

  face of the product by the sandblast.

  In this example, the sand jet scanning system is explained only for the upper part of the blast chamber 4 It would of course be possible to have a second identical system in the lower part of the blast chamber 4, to perform the

  sweeping the underside of the product 2.

  It goes without saying that the description given above has no

  limiting and that various modifications could be made

  without departing from the scope of the invention defined in the claims

attached.

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Claims (1)

  ) Device for descaling metallurgical products in   characterized in that it comprises: a metal housing (1) divided into three so as to define,   in the direction of movement of the product (2), a first vacuum chamber   ration (3), a blast chamber (4) and a second vacuum chamber   (5), the walls (6), (6 '), (7) and (7') of said chambers having openings (8), (9), (10) and (11) which are facing each other. others so as to provide a passage for the product (2), two sand injection nozzles (12) and (13) with a gas, for example compressed air, placed at the top and the part lower part of the sanding chamber (4) and oriented respectively towards the upper face and the lower face of the product (2), suction ducts (17), (18), (19) and (20) connected to the chambers of suction (3) and (5), a container (16) communicating with the lower part of the sanding chamber (4), said container being intended for the recovery of sand and calamine, and   means for preventing sand from passing vacuum chambers   ration (3) and (5) outside the housing (1).   ) Device according to claim 1, characterized in that the means for preventing sand from passing suction chambers (3) and (5) outside the housing (1) consist of two pairs of metal brushes (21). ), (21 ') and (22), (22') fixed on the walls   (6) and (6 ') of the suction chambers, the brushes of each   that pair being placed so as to be in contact respectively with   the upper face and the lower face of the product (2).   Device according to one of claims 1 or 2, characterized   in that it includes means to prevent the sand from passing from the   blast chamber (4) at the second suction chamber (5).   Device according to claim 3, characterized in that the means for preventing the sand from passing from the blast chamber (4) to the second suction chamber (5) consist of two metal brushes (23) and (23 ' ) fixed on the inner wall (7 ') of the second suction chamber (5) and placed so as to contact respectively the upper face and the lower face of the product (2).   Device according to one of Claims 1 to 4, characterized   in that it comprises, inside the blast chamber (4), means for preventing the sand from passing into the suction chambers (3) and (5).   Device according to claim 5, characterized in that the means for preventing the sand from passing from the blast chamber (4) into the suction chambers (3) and (5) consist of two pairs of metal plates (24). ), (24 ') and (25), (25'), the plates of each pair being arranged near the walls (7) and (7 ') of the   blast chamber and on both sides of the product (2), said   being arranged so as to be in contact, by one of their side, respectively with the upper face and the lower face of the product (2).   Device according to one of Claims 1 to 6, characterized   in that each of the injection nozzles (12) and (13) is mounted on a   mechanism back and forth perpendicular to the direction of scrolling the pro-   duit (2) so that the sand jet sweeps the face respectively   upper and lower side of the product (2).