FI120577B - Casting tray for pouring metal into a mold - Google Patents

Description

CASTING DISH FOR MOLDING METAL

The invention relates to a method and apparatus for pouring molten material such as molten metal into a mold. More particularly, the invention relates to a method and apparatus for casting anodes used in electrolytic purification.

Controlled pouring and precise metering of molten metal into the casting mold is essential, for example, when casting metal anodes. In the production of metals 10, the process step following the casting of the metal anodes is electrolytic purification, whereby the prerequisite for achieving a high cathode quality and efficiency is e.g. homogeneity of the anodes in both shape and weight. In most known methods, the anode is molded into an open mold.

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In the casting of anodes, such as copper anodes, the molten material is led from the anode furnace, for example, through a chute to an intermediate trough of the casting apparatus, from where the molten metal is further poured into the trough. The volume of the intermediate trough is considerably larger than that of the actual trough and also acts as a smoothing intermediate storage between the anode furnace 20 and the trough. The amount of metal at the beginning of the pour in the pouring pit is somewhat higher than the amount of metal to be dispensed into the casting mold at once. Usually about twice the amount of metal is poured into the casting pan relative to the amount poured into the casting mold. From the pouring tray, the molten metal is meticulously metered into an open casting mold. The drip tray is not dispensed 25 empty; copper base. Modern anode casting is automated in the so-called casting tables, where the casting molds are moved on a round casting table in front of the casting pan. When pouring from a trough, the dosing is controlled by monitoring the movement and speed of the trough and the weight of the trough. Typically, the amount of 30 molten pours poured into a copper anode mold is dispensed with an accuracy of 3 percent. The weight of the anode is usually between 300 and 600 kilograms.

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To accurately control the dosing of the amount of molten to be poured, the drip tray is equipped with weight sensors. The pouring is automatically controlled and starts when the pouring tray is filled with molten, the initial weight of the tray is measured, and the mold is placed in front of the pouring tray. When pouring, the pouring tray is tilted so that 5 molten metal flows over the pouring tray pouring spout into the casting mold. The tipping is directed to stop when the weight of the casting trough has been reduced by the target weight of the anode to be cast. The pouring pan is then returned to its original position for refilling.

10 During a single anode casting process, several hundred anodes are usually cast successively. At the end of the casting process, the cast pan is typically left full of metal and the metal is allowed to solidify in the cast pan. Necessary maintenance is carried out on the ladle, which often involves the renewal of the entire lining of the ladle. The present invention enables the cast pan to be completely emptied of metal, thus requiring less maintenance.

The anodes used for the electrolytic cleaning of metals are in the form of thick plates, about 30 to 100 millimeters thick. The anodes have a height of about 20,900 to 1,500 millimeters and a width of about 700 to 1,200 millimeters. In an electrolysis pool, the electrode plates hang vertically from the projections formed at the top of the plate, the so-called ears, resting on the sides of the pool. The anode ears are often formed of the anode metal during casting. Thus, the mold for the anode comprises a flat recess, or well, which is in the form of a cross-section of the anode and somewhat deeper than the thickness of the anode.

There are several requirements and problems associated with pouring molten metal into an anode mold. The molten metal must not spill onto the outside of the pit, or spill or move, so that the molten substance rises to the edges of the pit and solidifies into a game. Thus, the surface of molten metal poured into the mold must remain calm in order for the casting to solidify to its desired shape. On the other hand, the time spent on felling 3 should be as short as possible to keep production capacity at a profitable level.

The flow of molten metal has a lot of kinetic energy, which is applied to the bottom of the molding mold and to the molten material already in the mold during pouring 5, causing spillage and splashing. Therefore, it is essential that the height of the molten pour is as low as possible. On the other hand, the motion energy of the molten also disturbs the weighing of the casting pan. In order to minimize weighing errors, spillage and splashing, the aim is to have as smooth a fall as possible.

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US 5967219 describes a method for pouring molten metal into a casting mold so that weighing errors are reduced and the pouring is quiet. The invention disclosed in the publication is based on the design of the base of the casting pan and the controlled movement path of the pouring movement which conforms to the shape of the base of the casting pan 15. In order to achieve the desired result, the movement of the described trough must be calm and slow. However, such slow pouring results in the casting stage becoming a bottleneck in the overall process.

The object of the present invention is to eliminate the problems associated with the prior art and to provide a new type of casting tray and method for pouring molten metal into a low and flat casting mold. It is an object of the invention to provide the molten metal as quickly as possible with the molten metal so that the molten metal does not rise above the mold and that the molten metal applied to the mold remains as calm as possible.

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The present invention is based on the basic idea that the direction and amount of molten kinetic energy to be poured from a pouring trough is influenced by the shape of the trough. Thus, casting the metal into the mold is accomplished at as low a pour height as possible so that the metal does not receive high potential energy to rise beyond the edges of the mold. Casting is also accomplished such that the flow of molten metal receives a high horizontal flow rate relative to the vertical flow rate.

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The rapid pouring according to the invention is based on high mass flow in the initial stage of pouring. The gravity casting according to the invention is achieved by slowing down the mass flow in the final stage of pouring. The throttling is performed in accordance with the 5 most advantageous embodiments of the invention by a throttle body, such as a throttle block, which is positioned and shaped such that the uncharged molten metal flow at the beginning of the pour and the throttled flow at the final stage allow accurate metering. The throttle body allows for rapid tilt of the casting trough 10 without the flow of molten metal becoming uncontrolled.

In the invention, the flow profile of the molten metal discharged from the pouring pan is applied to substantially the entire width of the anode mold. The flow is directed substantially horizontally toward the wall opposite the casting tray, the back wall of the casting mold. The horizontal motion energy of the flow is initially quenched when the molt hits the bottom of the die and then collides with the pressure wall formed by the molten metal already in the die. The spreading of the flow profile is accomplished by the design of a pouring spout, for example a spout.

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The invention provides considerable advantages. The invention enables a faster casting process, which results in an increase in the capacity of the casting machine and the casting table. The solution of the invention substantially reduces the fluttering of the molten metal during the filling of the casting trough and thus increases the usable casting volume. The invention also reduces the corrugation of molten metal in the casting pan. The acceleration of the casting process is also based on the fact that the initial and final weighing of the casting tray can be done faster without waiting for the molten metal to swing, and that casting can be started at the maximum pouring rate without harmful splashing and splashing. By means of the invention, the casting mold is less worn out and the need for coating agent to be applied to the mold is reduced.

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The pouring tray according to the invention has a bottom, a spout, side walls adjacent to the bottom of the spout and a back wall opposite to the spout, and the spout is provided with a tilting mechanism fitted with at least one weight sensor to monitor the weight of the spout. The edge of the pouring spout 5 is substantially wide of the mold cavity, and the spout comprises substantially flush sidewalls adjacent to the bottom of the spout and an arcuate downwardly sloping spout with a throttle bar to slow the mass flow of metal

The frame of the pouring trough according to the invention may be, for example, made of steel, the lining of the trough being of refractory masonry or the like.

In accordance with a preferred embodiment of the invention, the throttle choke is shaped such that, when fitted between the side walls of the chute, the throttle opening, regardless of the skill of the installer, leaves a desired throttle opening. The throttle body is arranged such that, in the case of casting, the throttle opening is completely below the surface 20 of the molten metal. The throttle body may be a throttle block and preferably is a tile structure that is perpendicular to the flow direction of the molten metal! and a position substantially vertical to the bottom of the pouring pan. The throttle body is preferably toothed at its lower edge, whereby the throttle opening is delimited by the teeth of the throttle body and the bottom of the casting trough 25. The teeth projections may extend to the bottom of the pouring pan. The throttle brick may be formed by casting it firmly into the pouring tray by means of a suitable mold, by masonry or by attaching a suitable piece to the pouring tray. For example, steel wedges can be used as fastening elements.

In a pouring trough according to one embodiment of the invention, the throttle body is preferably disposed between the pouring spout and the rear wall so that 40 to 90% of the amount of metal to be molded can be charged in the space between the 6 throttling pieces and the pouring spout.

The weight of the trough according to the invention is measured by means of one or more weight sensors fitted in connection with the tipping mechanism of the trough 5. According to one embodiment of the invention, the tilt of the pouring trough can be implemented by the mechanism disclosed in US 5967219. According to another embodiment of the invention, the tilt of the casting can be implemented by a mechanism in which the front of the casting pan 10 is supported by a fixed support, with respect to which the casting pan can pivot when tilted and the rear of the casting pan is raised by a lifting mechanism such as a hydraulic cylinder. The inclination of the casting can may also be effected by any other suitable mechanism.

In the solution according to the invention, the flow of molten metal filing from a casting trough to a casting mold is shaped as desired by a pouring spout. The spout comprises a curved pouring surface from the bottom of the spout. The pouring surface is bounded by the pouring edge of the pouring spout and the bottom of the spout or the portion of the spout parallel to the bottom of the spout. The advantageous design of the spout 20 according to the invention is accomplished by all those spout shapes that project from the bottom portion of the spout and distribute the flow of molten metal evenly over the width of the spout. Viewed from above, the pouring spout has a curved, parabolic or variable radius. The top edge, particularly viewed from above, is preferably 25 parts of the circumference of the circle. The tipping surface widens towards the tipping edge. The pouring surface is defined by substantially straight lines drawn from the pouring edge to the bottom of the pouring pan. The angle of the pouring surface relative to the bottom of the pouring pan may vary from 12 to 55 degrees. Preferably, the pouring surface is a cutting cone. The width of the pouring edge is proportional to the width of the mold cavity so that the width of the pouring edge 30 is close to the width of the mold cavity.

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According to a preferred embodiment of the invention, the pouring spout is a separately manufactured spout. The beaker according to the invention can be made, for example, by casting into a mold. The material is fire-resistant material such as masonry or cast iron.

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The beaker shaped in accordance with the invention can be fitted to casting trays of various shapes to provide the desired advantageous design, flow rate and flow direction of the molten metal into the mold.

In the method of the invention, the molten metal of the metal anodes is poured into a flat casting pan, the metal is poured from the casting pan into the casting mold, controlling the mass flow rate of the molten metal from the casting to the casting The molten metal mass flow rate from the casting tray to the casting mold is higher at the initial stage of pouring, whereby at least 40%, preferably 70-80% of the casting metal is poured into the casting mold. The mass flow rate of the molten metal from the casting tray to the casting mold at the final stage of pouring is controlled by a throttle body fitted to 20 casting troughs. According to one embodiment of the invention, in the initial stage of the pour, the mass flow rate is controlled by means of the movement path of the casting pan. According to another embodiment of the invention, at the final stage of the pouring, the mass flow rate is controlled by both the movement path of the casting pan and the throttle 25 of the casting pan.

Figures 1a and 1b show pouring trays according to some embodiments of the invention.

Figure 2a shows a side view of a pouring tray and a casting mold according to an embodiment of the invention, viewed from the direction of the casting mold.

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Figure 2b is a top view of the pouring pan and the casting mold of Figure 2a.

Figures 3a and 3b show a sectional view A-A of the drip tray and mold according to Fig. 2a. Figures 3a and 3b also show the placement of the molten metal in the drip tray 5 and the pouring into the mold.

Figure 4a shows a top view of a spout brick according to an embodiment of the invention. Fig. 4b shows a side view of Fig. 4a beaker.

Figures 5a and 5b show a throttling brick according to a preferred embodiment of the invention.

1a has a curved bottom 16, side walls 14 and a rear wall 13. The throttle bracket 12 is disposed between the pouring spout, here the rear wall 13 of the spout 15 and 15. The throttle bracket 12 divides the space between the bottom and the walls into the front part 11 of the trough and the rear part 10 of the trough and the bottom 16 of the throttle 12 delimits the slots 19 through which molten metal flows from the rear 10 to the front 11. The height of the throttle 20 at least on the molten surface with the pouring tray in its filling position. When molten metal charging is carried out, the metal is divided into front 11 and rear 10 of the drip tray. Preferably, the molten metal is dispensed into space 10. The spout 15 has vertical side walls 17 and a pouring surface 9. The pouring surface 9 is curved downward and widens. The edge of the pouring spout 25 18 is curved from above and the pouring surface 9 is a cut from the cone. The volume of the rear part 10 of the pouring tray according to the embodiment of the invention shown in Figure 1 is larger than that of the front part 11 because the pouring tray widens at the throttle bracket 12 towards the rear wall 13. This solution allows a significantly larger amount of molten metal to be charged behind the throttle bracket 30 in space 10 than in space 11.

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Figure 1b shows a pouring tray according to a preferred embodiment of the invention having a curved bottom 16, side walls 14 and a rear wall 13. The spout 15 has vertical side walls 17 and a pouring surface 9. The pouring surface 9 is curved downwards and widens towards the edge 18 of the pouring spout. The edge of the pouring spout 5 18 is curved from above and the pouring surface 9 is a cut from the cone.

1a and 1b, the lining is made of refractory masonry and the frame is made of steel.

Figures 2a and 2b show a casting tray 30 and a copper anode casting mold 24 positioned therein. The casting mold 24 has an anode-shaped casting pit 31. In the embodiment of Figure 2, the sidewalls 27 extend parallel to and straight from the rear wall 23 to the cam 15 shaped. The throttle bracket 22 is disposed perpendicular to the side walls 27 and extends from the side wall to the side wall. At the bottom of the throttle bracket 22 there are two notches defining slots between the bottom 26 and the throttle bracket 22, from which molten metal flows from space 20 to space 21. Three pairs of upwardly supporting beams 39 are provided against side walls 27 . The position of the throttle bracket can be changed as needed at three points determined by three pairs of support beams. The throttle bracket 22 is supported in place by two wedges 61 and fastening members 62. Arrows 28 indicate the flow direction and flow swirls of the molten metal as the metal flows out of the pouring tray 30 and settles 25 into the hole 31 of the casting mold 24.

Figures 3a, 3b and 3c show section A-A of an embodiment of the invention shown in Figures 2a and 2b. In Fig. 3a, the cast pan 30 is in the filling position and filled with molten metal 32. In Fig. 3b, the cast pan 30 is inclined for pouring and the molten metal 32 flows from the casting pan 30 to the casting mold 24. In Fig. 3c, the cast pan 30 is returned to the filling position. The bottom 26 of the trough is curved so that the height hm of the molten metal 10 is small relative to the length of the trough measured from the rear wall 23 to the cam brick 25.

The spout brick 40 of Figure 4 is fitted to the pouring pan. The beaker 5 can be made separately, for example, by casting a refractory material. The cam brick comprises a pouring surface 49 and a bottom portion 41 which is arranged parallel to the bottom of the pouring pan. The cam brick has substantially vertical side walls 42, 43. At the pouring surface, the side walls 43 are lowered 10 towards the edge of the pouring surface 45. The radius of rounding between the surfaces 41 and 49 is preferably 0.5 to 800 mm.

Figures 4a and 4b show the spout brick of Fig. 4 positioned in front of and above the mold 44 in the operating position. The pouring surface 49 of the cam brick widens towards the 15 cutting edge 45. The radius of curvature r of the pouring edge is proportional to the width A of the mold, and the length of the radius of curvature r is preferably 0.2 to 6 times the dimension of A. The length B of the pouring surface depends on the selected brick height E relative to the casting mold and the angle of the conical surface with respect to the direction 41 of the bottom portion 41 of the epsilon (ε). The angle epsilon (ε) is preferably between 12 and 55 degrees. Preferably, the width C of the cam brick is 0.3-0.95 times the width A of the die mold, particularly preferably 0.5-0.8 times the width A. The dimension D of the cam face 41 is selected so that the cam brick is suitably integrated with other mold design. Advantageously, the operation of the cam brick is affected by minimizing the pitch F. The felling height can be, for example, between 70 and 400 mm, preferably between 130 and 200 mm. The width K of the pouring edge 45 is preferably 0.5 to 0.98 times the width A of the die mold, more preferably 0.6 to 0.7 times the width A of the die mold.

The throttle block 50 shown in Figures 5a and 5b has a tooth formed by three notches 51, 52, 53. The height of the throttle block extends at least from the bottom of the pouring pan to the top of the side walls. The height hi of the notches in the copper casting is preferably 10 to 100 millimeters. The total area of the notches 11 is preferably between 1500 and 17000 square millimeters. In practical work, the total surface area of the notches can easily be enlarged simply by slitting the teeth of the brick. Thus, in order to find a suitable notch surface, it is preferable to start casting with a throttle having several teeth. The height and total surface area of the notch or slots of the throttle are essential for the pouring of the 5 castings according to the invention. The sum of the notches' widths 11 + 12 + 13 is preferably 0.05-0.9 times the brick width It. The brick thickness dt may be less than 5 millimeters or more than 100 millimeters, preferably between 5 and 100 millimeters.

It will be apparent to one skilled in the art that various embodiments of the invention are not limited to the foregoing, but may vary within the scope of the appended claims.

Claims (30)

A pouring trough (30) for pouring metal into a casting mold (24) having a bottom (16), a pouring spout (15, 25), side walls (14) adjacent to the bottom of the pouring trough bottom and a rear wall (13) opposite to the pouring spout the pouring trough (30) being provided with a pouring mechanism fitted with at least one weight sensor for accurately dispensing metal to the casting mold (24), characterized in that the pouring spout comprises a pouring surface (9) extending towards the pouring edge (18) of the pouring spout (15). in the direction of the bottom of the pouring trough (30), and the sidewalls (14) adjacent to the bottom of the pouring trough (30) substantially parallel to the bottom of the pouring trough, wherein the bottom (16) and the rear wall (13) a throttle body (12, 22) for slowing down the mass flow of molten metal from the space 15 between the rear wall and the throttle body (12, 22). Casting trough (30) according to claim 1, characterized in that the throttle body (12, 22) is disposed between the pouring trough spout (15, 25) and the rear wall (13, 23) so that the throttling part (12, 22) and the pouring spout (12). 15, 25), 40 to 90% of the amount of metal to be poured into the casting mold can be charged. A drain pan (30) according to claim 1, characterized in that the throttle body (12, 22) is arranged such that in the casting case one or more throttle openings (19, 51, 52, 53) delimited by the throttle body (12, 22) below the metal surface. Casting trough (30) according to claim 1, characterized in that the throttle body (12, 22) is a plate-like structure which is arranged perpendicular to the flow direction of the molten metal and substantially vertical to the bottom of the casting trough (16, 26). Drain tray (30) according to claim 1, characterized in that the throttle body (12, 22) is toothed at its lower edge, the throttle opening being delimited by the teeth of the throttle body and the bottom of the trough. 5 Drain tray (30) according to claim 5, characterized in that the notches (19, 51, 52, 53) of the throttle body have a height of 10 to 100 millimeters. A pouring trough (30) according to claim 5, characterized in that the notches (19, 51, 52, 53) of the throttle body have a total area of between 1500 and 17000 square millimeters. A drain pan (30) according to claim 5, characterized in that the sum of the widths of the notches (19, 51, 52, 53) of the throttle is 0.05 to 0.9 times the width of the throttle. A pouring tray (30) according to claim 1, characterized in that the height of the throttle (12, 22) is selected so as to extend from the bottom of the pouring tray (30) to at least the molten surface with the pouring tray 20 in its filling position. Casting trough (30) according to claim 1, characterized in that the top (18, 45) of the pouring spout is curved, parabolic or variable in radius, preferably part of the circumference of the circle. 25 A pouring tray (30) according to claim 1, characterized in that the angle of the pouring surface relative to the bottom of the pouring tray varies between 12 and 55 degrees. A pouring tray (30) according to claim 1, characterized in that the pouring surface is a conical section. Casting tray (30) according to claim 1, characterized in that the width (K) of the pouring edge 45 is preferably 0.5-0.98 times the width (A) of the pouring pit, more preferably 0.6-0.7 times the width (A) of the pouring pit. . A manhole (30) according to claim 1, characterized in that the manhole is formed by a spout (40) which can be separately manufactured and fitted to the manifold. Casting tray (30) according to claim 14, characterized in that the spout (40) is made of a refractory material, such as masonry or cast iron, by casting into a mold. A pouring trough (30) according to claim 14, characterized in that the cam brick (40) has a bottom part 15 (41) which is arranged parallel to the bottom of the trough, a pouring surface (49) which curves downward from the bottom part (41) and widens towards the pouring edge (45). (41) with substantially vertical side walls (42, 43). Casting tray (30) according to claim 16, characterized in that the pouring edge (45) has a radius of curvature (r) proportional to the width (A) of the casting pit, wherein the radius of curvature (r) is preferably 0.2 to 6 times the width (A). ). Casting tray (30) according to claim 16, characterized in that the inclination (epsilon) of the pouring surface (49) is 12 to 55 degrees with respect to the bottom part (41) of the spout. Casting tray (30) according to Claim 16, characterized in that the narrowest width (C) of the spout (40) is 0.3 to 0.8 times the width (A) of the casting pit 30. Casting tray (30) according to claims 14-16, characterized in that the cam brick (40) has a pouring surface (49) which curves downwardly from the bottom part of the casting mold and widens towards the pouring edge (45) and substantially vertical side walls (42, 43). 5 Casting tray (30) according to claim 20, characterized in that the pouring edge (45) has a radius of curvature (r) proportional to the width (A) of the casting pit, wherein the radius of curvature (r) is preferably 0.2 to 6 times the width (A). . 10 Drain tray (30) according to Claim 20, characterized in that the inclination (epsilon) of the pouring surface (49) is 12 to 55 degrees with respect to the bottom part (41) of the spout. Drain tray (30) according to claim 20, characterized in that the narrowest width (C) of the spout (40) is 0.3 to 0.95 times the width (A) of the duct mold. A pouring trough (30) according to claim 20, characterized in that the edge (18, 45) of the pouring spout 20 is curved from above, preferably of parabolic or variable radius. A pouring spout (30) according to claim 24, characterized in that the edge (18, 45) of the spout is viewed from above as part of the circumference of the circle. 25 A pouring tray (30) according to claim 20, characterized in that the angle of the pouring surface relative to the bottom of the pouring tray varies between 12 and 55 degrees. Casting tray (30) according to Claim 20, characterized in that the pouring surface (9, 29, 49) of the pouring spout is a conical section. Casting tray (30) according to claim 20, characterized in that the pouring spout is formed by a spout (40) which can be separately manufactured and adapted to the pouring tray (30). Casting tray (30) according to claim 20, characterized in that the spout (40) is made of a refractory material, such as masonry or cast iron, by casting into a mold. Casting tray (30) according to claim 20, characterized in that the width (K) of the pouring edge (45) is preferably 0.5-0.98 times the width (A) of the pouring pit, more preferably 0.6-0.7 times the width of the pouring pit. (A).