Molten metal filtration unit and molten metal filtration apparatus in which to dispose said filtration unit

Abstract

The present invention addresses the problem of providing a molten metal filtration unit which is more easily disposed in a filtration chamber as compared with conventional molten metal filtration units. The present invention also addresses the problem of providing a molten metal filtration apparatus in which a molten metal filtration unit is easily disposed. Said problems are solved by a molten metal filtration unit that includes a pair of side plates and a substantially cylindrical filtration tube connected to the pair of side plates substantially perpendicularly, wherein the pair of side plates includes a first side plate which is provided with a through hole at the location of connection to the filtration tube and a second side plate in which the location of connection to the filtration tube is blocked, and at least one of the pair of side plates is provided with a bottom part which is formed such that, if the longitudinal direction of the filtration tube is substantially horizontal and the first side plate is positioned on the left side of the filtration tube and the second side plate is positioned on the right side of the filtration tube, one of the left and right bottom sides is positioned vertically higher than the other.

Description

Molten metal filtration unit and molten metal filtration device in which said filtration unit is arranged

[0001] The present invention relates to a molten metal filtration unit and a molten metal filtration device to be installed in a molten metal filtration device that filters molten metal such as aluminum. More specifically, the present invention relates to a molten metal filtration unit and a molten metal filtration device that facilitates the installation of a filtration chamber at a predetermined position when the molten metal filtration unit is installed in the filtration chamber of the molten metal filtration device.

[0002] Molten metals such as aluminum used in the production of castings typically contain impurities such as hydrogen and non-metallic inclusions, such as oxides. For example, dissolved hydrogen in the molten metal can form cavities called porosity in the casting, and oxides and other substances can become inclusions in the casting. These cavities and inclusions are undesirable because they can be the starting point for fracture in the casting. Therefore, filtration devices have been developed to filter the molten metal and remove impurities such as inclusions contained in the molten metal.

[0003] To achieve this goal, a molten metal filtering device is typically used in which a molten metal filtering unit having a plurality of ceramic filter tubes for filtering impurities from the molten metal is placed in a filtering chamber provided with an inlet and an outlet (see Patent Document 1). In such a molten metal filtering device, the molten metal filtering unit needs to be taken in and out of the filtering chamber before and after use. Therefore, the molten metal unit needs to be moved to a predetermined position in the filtering chamber before use.

[0004] As a means for moving the molten metal unit to a predetermined position in the filtering chamber, a method of pressing the molten metal filtering unit with a hydraulic jack or a pantograph jack or the like is employed.

[0005] JP 2014-210254 A

[0006] However, due to its weight, it is difficult to accurately move the molten metal filtration unit to a predetermined position by means of pressing, etc. In particular, in filtration of molten metal, the molten metal filtration unit needs to be in close contact with the outlet side of the filtration chamber, but due to its weight, it is difficult to finely adjust the position of the molten metal filtration unit.

[0007] Therefore, the problem to be solved by the present invention is to provide a molten metal filtration unit that eliminates the above-mentioned disadvantages, i.e., that is easier to place at a predetermined position within a filtration chamber compared to conventional molten metal filtration units. Also, the problem to be solved by the present invention is to provide a molten metal filtration device that facilitates easy placement of the molten metal filtration unit at a predetermined position. Note that throughout this specification, the "molten metal filtration unit" may also be referred to simply as the "filtration unit." Also, throughout this specification, the "molten metal filtration device" may also be referred to simply as the "filtration device."

[0008] After extensive research, the inventors have found that the above-mentioned problems can be solved by improving the shape of the bottoms of the pair of side plates that make up the filtration unit. Specifically, the inventors discovered that by providing a bottom in which at least one of the pair of side plates has a bottom that is vertically higher than the other bottom when the filtration unit is in a specific "horizontal" position, the operability of moving the filtration unit to a desired position within the filtration chamber and fine-tuning its placement can be improved due to the weight of the filtration unit itself, i.e., due to the imbalance in the weight of the filtration unit. In this specification, the expression "imbalance in weight balance" of the filtration unit refers to the imbalance in weight balance of the overall structure or the partial structure when compared to a conventional filtration unit, as described below as a typical example.

[0009] A typical aspect of the present invention is as follows: A molten metal filtering unit comprising: a pair of side plates; and a substantially cylindrical filter tube connected substantially perpendicularly to the pair of side plates, wherein the pair of side plates comprise: a first side plate having a through hole at a location connected to the filter tube; and a second side plate the location connected to the filter tube is closed, and when the longitudinal direction of the filter tube is substantially horizontal and the first side plate is located on the left side of the filter tube and the second side plate is located on the right side of the filter tube, at least one of the pair of side plates comprises a bottom portion formed so that either the left side bottom edge or the right side bottom edge is positioned vertically higher than the other bottom edge.

[0010] According to the filtration unit of the present invention, when the longitudinal direction of the filtration tube is approximately horizontal, the first side plate is located on the left side of the filtration tube, and the second side plate is located on the right side of the filtration tube, at least one of the pair of side plates has a bottom portion formed so that either the left or right bottom edge is located vertically higher than the other bottom edge, thereby providing an excellent advantage that could not be predicted from conventional filtration units, in that the weight imbalance of the filtration unit within the filtration chamber of the filtration device makes it easy to move the filtration unit to a desired position and fine-tune its placement, thereby contributing to the efficiency of the entire installation process of the filtration device.Furthermore, when the filtration unit is placed at a desired position within the filtration chamber of the filtration device, specifically along a wall surface such as a location with a tap outlet, the weight imbalance of the filtration unit presses the filtration unit against the wall surface, thereby providing an additional excellent advantage that the filtration unit can be placed stably in the correct position.

[0011] Fig. 1 shows a typical example of a conventional filtration unit and filtration device. Fig. 2 shows an enlarged view of a first side plate when a conventional filtration unit is installed in a filtration device. Fig. 3 shows a schematic view of a first side plate of a filtration unit according to one embodiment of the present invention. Fig. 4 shows a schematic view of a first side plate of a filtration unit according to one embodiment of the present invention. Fig. 5 shows a schematic view of a first side plate of a filtration unit according to one embodiment of the present invention. Fig. 6 shows an enlarged view of the first side plate of a filtration unit according to one embodiment of the present invention and the hearth of the filtration device.

[0012] The filtration unit of the present invention is disposed in a filtration chamber of a filtration device. To facilitate understanding of the features of the filtration unit of the present invention, a typical example of a conventional filtration unit and filtration device will first be described with reference to FIG.

[0013] 1 shows a filtration device 101, which includes an inlet 102, a filtration chamber 103, a tapping chamber 105, and tapping outlets 106 and 110. The filtration unit 104 includes a first side plate 107, a second side plate 108, and a substantially cylindrical filtration tube 109 connected substantially perpendicularly to the side plates. Although not shown in FIG. 1, the first side plate 107 has a through-hole at the location connected to the filtration tube 109, and the second side plate 108 has a closed location connected to the filtration tube 109.

[0014] Furthermore, FIG. 1 is a schematic diagram of the entire filtration device observed from a direction in which the longitudinal direction of the filtration tube is approximately horizontal, the first side plate is located on the left side of the filtration tube, and the second side plate is located on the right side of the filtration tube. However, in this specification, unless otherwise specified, the filtration unit and the filtration device will be described as being observed from the same direction.

[0015] In molten metal filtering, a filtration unit 104 is disposed in a filtration chamber 103, and molten metal, such as aluminum or an aluminum alloy, is supplied to the inlet 102. The molten metal supplied from the inlet 102 passes through a filtration tube 109 provided in the filtration unit 104 disposed in the filtration chamber 103, thereby removing impurities such as oxides contained in the molten metal. The filtered molten metal flows from the filtration tube 109 through a through-hole provided in the first side plate 107, into the tapping chamber 105 from the tapping outlet 110, and then passes through the tapping chamber 105 before being discharged from the tapping outlet 106. The discharged molten metal is sent to a molten metal storage device, a metal processing device (neither of which are shown) that processes the molten metal, or the like.

[0016] Fig. 2 is an enlarged view of the bottom of the first side plate 107 of the filtration unit 104 in Fig. 1. In the side plates 107 and 108 of the conventional filtration unit 104, as shown in Fig. 2, the bottoms of the side plates are formed so that the entire bottoms of the side plates come into contact with the hearth 201 of the filtration chamber 103. That is, in Fig. 2, the bottom of the first side plate 107 is arranged so as to be perpendicular to the side surface on the tap port side (left side in the figure) and the side surface on the filtration tube side (right side in the figure). Note that while only the first side plate 107 has been described, the second side plate 108 also has a similar bottom.

[0017] In the filtration unit of the present invention, at least one of the pair of side plates has a bottom portion formed so that either the left or right bottom edge is positioned vertically higher than the other bottom edge.

[0018] For example, as shown in FIG. 3 , the left side bottom edge 301 of the first side plate 107 can be formed so as to be positioned vertically higher than the right side bottom edge 302 of the first side plate 107. In this case, the other side plate (i.e., the second side plate) of the pair of side plates may be formed so that the left side bottom edge is positioned vertically higher than the right side bottom edge, as with the first side plate, or so that the right side bottom edge is positioned vertically higher than the left side bottom edge, or so that the left and right bottom edges are positioned at approximately the same height in the vertical direction. Furthermore, the shape of the bottom portion of the first side plate, which is formed so that the left side bottom edge is positioned vertically higher than the right side bottom edge of the first side plate, is not particularly limited. The shape of the bottom portion may be such that a portion of the bottom is inclined, as shown in FIG. 3 , or the entire bottom portion may be inclined. Furthermore, the shape of the bottom portion may be such that a portion of the bottom portion has a step portion so that the left side bottom edge of the first side plate is positioned vertically higher than the right side bottom edge of the first side plate.

[0019] The right-side bottom edge of the first side panel may be formed so as to be vertically higher than the left-side bottom edge of the first side panel. In this case, the other side panel (i.e., the second side panel) of the pair of side panels may be formed so as to have the right-side bottom edge vertically higher than the left-side bottom edge, as with the first side panel, or so as to have the left-side bottom edge vertically higher than the right-side bottom edge, or so as to have the left-side bottom edge and the right-side bottom edge at approximately the same vertical height. The shape of the bottom portion of the first side panel formed so that the right-side bottom edge is vertically higher than the left-side bottom edge of the first side panel is not particularly limited. The shape of the bottom portion may be such that a portion of the bottom portion is inclined, the entire bottom portion is inclined, or a portion of the bottom portion may have a step portion so that the right-side bottom edge of the first side panel is vertically higher than the left-side bottom edge of the first side panel.

[0020] Regardless of the shape of the bottom of the first side panel, the left or right bottom edge of the second side panel can be formed so that it is positioned vertically higher than the other bottom edge. That is, the second side panel may be formed so that the right bottom edge is positioned vertically higher than the left bottom edge, or so that the left bottom edge is positioned vertically higher than the right bottom edge. The shape of the bottom of the second side panel formed so that the left or right bottom edge is positioned vertically higher than the other bottom edge is not particularly limited. The shape of the bottom may be such that a portion of the bottom is inclined, or a portion of the bottom may have a step, as in the case where the right bottom edge of the first side panel is positioned vertically higher than the left bottom edge of the first side panel.

[0021] In the filtration unit of the present invention, at least one of the pair of side plates has a bottom portion formed so that either the left or right bottom edge is positioned vertically higher than the other bottom edge. This allows the filtration unit to be easily moved to a desired position and fine-tuned within the filtration chamber of the filtration device by balancing its weight. This contributes to improving the efficiency of the entire installation process of the filtration device. Furthermore, when the filtration unit is positioned at a desired position within the filtration chamber of the filtration device, specifically along a wall surface such as a location where the tap is located, the filtration unit's weight balance causes it to press against the wall surface, thereby achieving a stable positioning in an accurate position. This effect is particularly pronounced in an embodiment in which the left bottom edge (the bottom edge on the tap side) of the first side plate is positioned vertically higher than the right bottom edge.

[0022] In one embodiment of the present invention, in the filtration unit, if the first side plate has a bottom formed such that the left bottom edge is positioned vertically higher than the right bottom edge, the second side plate may have a bottom formed such that the left bottom edge is positioned vertically higher than the right bottom edge. Alternatively, in the filtration unit, if the first side plate has a bottom formed such that the right bottom edge is positioned vertically higher than the left bottom edge, the second side plate may have a bottom formed such that the right bottom edge is positioned vertically higher than the left bottom edge.

[0023] 3, when the left-side bottom edge 301 of the first side plate 107 is formed to be vertically higher than the right-side bottom edge 302 of the first side plate 107, the other of the pair of side plates (i.e., the second side plate) is also formed to have its left-side bottom edge positioned vertically higher than its right-side bottom edge, similar to the first side plate. Also, when the right-side bottom edge of the first side plate is formed to be vertically higher than the left-side bottom edge of the first side plate, the other of the pair of side plates (i.e., the second side plate) is also formed to have its right-side bottom edge positioned vertically higher than the left-side bottom edge, similar to the first side plate.

[0024] By forming the bottoms of both side plates so that either the left or right bottom edge is positioned vertically higher, the weight balance of the filtration unit can be shifted to either the left or right side within the filtration chamber of the filtration device, making it easier to move the filtration unit to a desired position and fine-tune its placement. This further improves the efficiency of the installation process of the filtration device. Furthermore, when the filtration unit is placed in a desired position within the filtration chamber of the filtration device, specifically, along a wall surface such as a location where the tap outlet is located, the weight balance of the filtration unit can be shifted to either the left or right side, causing it to press against the wall surface due to its own weight, thereby achieving a stable placement in an accurate position. This effect is particularly pronounced in embodiments in which the left bottom edge (the bottom edge on the tap side) of both the first side plate and the second side plate is positioned vertically higher than the right bottom edge.

[0025] In this embodiment, the bottoms of the pair of side panels are not particularly limited as long as either the left or right bottom edge is positioned vertically higher. The shape of the bottoms may be such that a portion of the bottoms is inclined, the entire bottoms are inclined, or a portion of the bottoms includes a step, so that the left bottom edge of the pair of side panels is positioned vertically higher than the right bottom edge. Furthermore, the shape of the bottoms may be such that a portion of the bottoms is inclined, the entire bottoms are inclined, or a portion of the bottoms includes a step, so that the right bottom edge of the pair of side panels is positioned vertically higher than the left bottom edge.

[0026] In one embodiment of the present invention, the filtration unit may have a step portion formed in at least one of a pair of side plates such that either the left or right bottom edge is positioned vertically higher than the other bottom edge.

[0027] For example, as shown in Fig. 4, the filtration unit may include a first side plate 107 having a stepped portion formed such that the left bottom edge is positioned vertically higher than the right bottom edge. In this case, the other side plate (i.e., the second side plate) of the pair of side plates may be formed such that the left bottom edge is positioned vertically higher than the right bottom edge, as with the first side plate, or such that the right bottom edge is positioned vertically higher than the left bottom edge, or such that the left and right bottom edges are positioned at approximately the same height vertically. Furthermore, in this embodiment, the shape of the bottom of the second side plate is not particularly limited.

[0028] In this embodiment, the filtration unit may include a first side plate having a step portion formed so that the right bottom edge is positioned vertically higher than the left bottom edge. In this case, the other side plate of the pair of side plates (i.e., the second side plate) may be formed so that the right bottom edge is positioned vertically higher than the left bottom edge, as with the first side plate, or so that the left bottom edge is positioned vertically higher than the right bottom edge, or so that the left and right bottom edges are positioned at approximately the same height in the vertical direction. Furthermore, in this embodiment, the shape of the bottom of the second side plate is not particularly limited.

[0029] The filtration unit has a step in at least one of the pair of side plates, where either the left or right bottom edge is positioned vertically higher than the other bottom edge. This allows the filtration unit to be easily moved to a desired position and fine-tuned within the filtration chamber of the filtration device, due to the weight imbalance, as in the case of an inclined shape. This contributes to improving the efficiency of the entire installation process of the filtration device. Furthermore, when the filtration unit is positioned at a desired position within the filtration chamber of the filtration device, specifically, along a wall surface such as a location where the tapping port is located, the weight imbalance of the filtration unit presses against the wall surface, thereby achieving a stable positioning in the correct position. This effect is particularly pronounced in an embodiment in which the step is provided so that the left bottom edge (the bottom edge on the tapping side) of the first side plate is positioned vertically higher than the right bottom edge.

[0030] In this embodiment, the filtration unit preferably has a pair of side plates each having a stepped portion formed so that the left bottom edge is positioned vertically higher than the right bottom edge. That is, as shown in Fig. 4, in the filtration unit, the first side plate has a stepped portion formed so that the left bottom edge is positioned vertically higher than the right bottom edge, and the second side plate has a stepped portion formed so that the left bottom edge is positioned vertically higher than the right bottom edge, similar to the first side plate.

[0031] By forming the bottom of the filtration unit in this way, when it is placed at a desired position in the filtration chamber of the filtration device, specifically, along the wall of the area where the tapping outlet is located, the weight of the filtration unit is biased in one direction, causing it to press against the wall (to the left in Figure 4) due to its own weight, thereby achieving a stable placement state in an accurate position. As a result, it becomes easy to place the filtration unit so that it is in accurate contact with the wall on the tapping outlet side.

[0032] 4 , when the filtration unit has a step portion at the bottom of the side plate, the lowest portion is referred to as a first bottom portion 401. Furthermore, a bottom portion formed so as to be positioned vertically higher than the first bottom portion is referred to as a second bottom portion 402. Although not shown, the side plate of the filtration unit may further have one or more step portions between the first bottom portion 401 and the second bottom portion 402. The shapes of the first bottom portion 401 and the second bottom portion 402 are not particularly limited, but it is preferable that the first bottom portion 401 and the second bottom portion 402 be approximately horizontal when the longitudinal direction of the filtration tube is approximately horizontal.

[0033] As shown in FIG. 4 , the horizontal length of the first bottom portion 401 is defined as W1. The horizontal length of the second bottom portion 402 is defined as W2. W1 and W2 are lengths parallel to the longitudinal direction of the filtration tube. Although not shown, if the side plates of the filtration unit further include a step between the first bottom portion 401 and the second bottom portion 402, the length W1 of the first bottom portion 401, which is the lowest portion, may be defined, and the horizontal length of the remaining side plates may be defined as W2. In other words, the sum of W1 and W2 is equal to the horizontal length (thickness) of the side plates.

[0034] 4, the vertical length from the first bottom 401 to the second bottom 402 is defined as H2. Although not shown, if the side plate of the filtration unit further includes a step between the first bottom 401 and the second bottom 402 or if the second bottom is not parallel to the longitudinal direction of the filtration tube, the vertical length H2 from the first bottom to the second bottom may be determined based on the left end of the second bottom.

[0035] In one embodiment of the present invention, the ratio (W1 / W2) of the horizontal length W1 of the first bottom portion to the horizontal length W2 of the second bottom portion may be 0.1 or more and 6.0 or less. W1 / W2 may preferably be 0.5 or more and 5.0 or less, and more preferably 0.8 or more and 2.0 or less. When W1 / W2 is 0.1 or more, the weight imbalance of the filtration unit is maintained within an appropriate range, allowing the filtration unit to be stably placed in the filtration chamber of the filtration device. When W1 / W2 is 6.0 or less, the weight imbalance of the filtration unit is increased, allowing the filtration unit to exert a greater pressing force against the wall surface.

[0036] In one embodiment of the present invention, the ratio (W1 / H2) of the horizontal length W1 of the first bottom to the vertical length H2 from the first bottom to the second bottom may be 0.1 or more and 11 or less. W1 / H2 may preferably be 0.2 or more and 10 or less, and more preferably 0.3 or more and 8.0 or less. When W1 / H2 is 0.1 or more, the weight imbalance of the filtration unit is maintained within an appropriate range, allowing the filtration unit to be stably placed in the filtration chamber of the filtration device. When W1 / H2 is 11 or less, the weight imbalance of the filtration unit is increased, allowing the filtration unit to exert a greater pressing force against the wall surface in the filtration chamber of the filtration device.

[0037] In one embodiment of the present invention, the filtration unit can have a bottom portion in which at least one of a pair of side plates is formed so that either the left or right bottom edge is positioned vertically higher than the other bottom edge, and which has a first bottom portion that is the lowest part and a sloped portion connecting the first bottom portion to the bottom edge that is positioned vertically higher.

[0038] 5, when the filtration unit has an inclined portion 502 at the bottom of the side plate, the lowest portion 501 is referred to as a first bottom portion. Also, the first bottom portion, which is the lowest portion, and the bottom portion 502 connecting the first bottom portion to the bottom edge positioned higher in the vertical direction are referred to as an inclined portion.

[0039] In this embodiment, as shown in FIG. 5 , the filtration unit may include a first side plate 107 having a bottom portion with a left bottom edge positioned vertically higher than a right bottom edge, the first bottom edge 501 being the lowest portion, and an inclined portion 502 connecting the first bottom edge 501 to the vertically higher bottom edge. In this case, the other side plate (i.e., the second side plate) of the pair of side plates may be formed such that the left bottom edge is positioned vertically higher than the right bottom edge, as with the first side plate, or such that the right bottom edge is positioned vertically higher than the left bottom edge, or such that the left and right bottom edges are positioned at approximately the same vertical height. The shape of the bottom of the second side plate is not particularly limited, and when one bottom edge is positioned vertically higher than the other bottom edge, it may include a stepped portion or an inclined portion.

[0040] In this embodiment, the filtration unit may include a first side plate having a right bottom edge positioned vertically higher than a left bottom edge, and a bottom edge having a first bottom edge as the lowest portion and a sloped portion connecting the first bottom edge to the vertically higher bottom edge. In this case, the other side plate (i.e., the second side plate) of the pair of side plates may be formed such that the right bottom edge is positioned vertically higher than the left bottom edge, similar to the first side plate, or such that the left bottom edge is positioned vertically higher than the right bottom edge, or such that the left and right bottom edges are positioned at approximately the same vertical height. The shape of the bottom of the second side plate is not particularly limited, and when one bottom edge is positioned vertically higher than the other bottom edge, it may include a stepped portion or a sloped portion.

[0041] The filtration unit has at least one of a pair of side plates formed so that either the left or right bottom edge is positioned vertically higher than the other bottom edge, and includes a bottom edge having a first bottom edge, which is the lowest part, and a sloped portion connecting the first bottom edge to the higher bottom edge. This allows the filtration unit to be easily moved to a desired position and fine-tuned for placement within the filtration chamber of the filtration device, due to the weight imbalance, as in the case of a stepped portion. This contributes to improving the efficiency of the overall installation process of the filtration device. Furthermore, when the filtration unit is placed at a desired position within the filtration chamber of the filtration device, specifically, along a wall surface such as a location where the tapping port is located, the weight imbalance of the filtration unit presses against the wall surface, thereby achieving a stable placement in the correct position. This effect is particularly pronounced in embodiments in which the left bottom edge (the bottom edge on the tapping side) of the first side plate is sloped so that it is positioned vertically higher than the right bottom edge.

[0042] 5, the horizontal length of the first bottom portion 501 is defined as W1'. The horizontal length of the inclined portion 502 is defined as W2'. W1' and W2' are lengths parallel to the longitudinal direction of the filtration tube.

[0043] 5, the vertical length from the end of the inclined portion 502 that contacts the first bottom portion 501 to the other end of the inclined portion 502 is defined as H2'.

[0044] Furthermore, as shown in FIG. 5, the angle formed by the inclined portion 502 and the vertical direction is set to θ1.

[0045] In one embodiment of the present invention, the ratio (W1' / W2') of the horizontal length W1' of the first bottom portion to the horizontal length W2' of the inclined portion may be 0 or more and 6.0 or less. W1' / W2' may preferably be 0.1 or more and 5.5 or less, and more preferably 0.5 or more and 2.0 or less. When W1' / W2' is 0 or more, the weight imbalance of the filtration unit is maintained within an appropriate range, allowing the filtration unit to be stably placed in the filtration chamber of the filtration device. When W1' / W2' is 6.0 or less, the weight imbalance of the filtration unit is increased, allowing the filtration unit to exert a greater pressing force against the wall surface.

[0046] In one embodiment of the present invention, the ratio (W1' / H2') of the horizontal length W1' of the first bottom to the vertical length H2' from the end of the inclined portion that contacts the first bottom to the other end of the inclined portion may be 0 or greater and 320 or less. W1' / H2' may preferably be 0.1 or greater and 160 or less, and more preferably 1.5 or greater and 100 or less. When W1' / H2' is 0 or greater, the weight imbalance of the filtration unit is maintained within an appropriate range, allowing the filtration unit to be stably placed in the filtration chamber of the filtration device. When W1' / H2' is 320 or less, the weight imbalance of the filtration unit is increased, allowing the filtration unit to exert a greater pressing force against the wall surface.

[0047] In one embodiment of the present invention, the angle θ1 between the inclined portion and the vertical direction may be 60° or more and 89° or less. θ1 may preferably be 75° or more and 89° or less, more preferably 85° or more and 89° or less. When θ1 is within the above range, the filtration unit can be easily moved to a desired position and fine-tuned for placement due to weight imbalance within the filtration chamber of the filtration device. Furthermore, the filtration unit itself is stabilized when placed alone. Furthermore, the filtration unit can be more appropriately positioned in the molten metal filtration device described below. This contributes to improving the efficiency of the entire installation process of the filtration device. When the filtration unit is positioned at a desired position within the filtration chamber of the filtration device, specifically, along a wall surface such as a location where the tapping port is located, the weight imbalance of the filtration unit causes pressure due to its own weight against the wall surface, thereby achieving a stable placement state in an accurate position. This effect is particularly pronounced in an embodiment in which the inclination is arranged so that the left bottom edge (bottom edge on the tapping side) of the first side plate is positioned vertically higher than the right bottom edge.

[0048] In one embodiment of the present invention, the filtration unit can have a pair of side plates, each of which is formed so that the left bottom edge is positioned vertically higher than the right bottom edge, and which has a first bottom edge that is the lowest part and a bottom edge that has a sloped part connecting the first bottom edge to the left bottom edge.

[0049] By forming the bottom of the filtration unit in this way, when it is placed at a desired position within the filtration chamber of the filtration device, specifically, along the wall of the location where the tapping outlet is located, the weight of the filtration unit is pressed against the wall of the filtration device on the tapping outlet side due to the imbalance in the weight balance of the filtration unit in one direction, thereby achieving a stable placement state in an accurate position. As a result, it becomes particularly easy to place the filtration unit so that it is in accurate contact with the wall on the tapping outlet side.

[0050] In one aspect of the present invention, the filtration unit can have a pair of side plates, each of which is formed so that the right-side bottom edge is positioned vertically higher than the left-side bottom edge, and which has a first bottom edge that is the lowest part and a bottom edge that has a sloped part connecting the first bottom edge to the right-side bottom edge.

[0051] By forming the bottom of the filtration unit in this manner, it becomes easier to arrange it so that it comes into accurate contact with the wall surface of the tap opening side in the filtration device described below.

[0052] The side plate of the filtration unit of the present invention has a characteristic bottom shape as described above, but the method for forming the bottom shape is not particularly limited. For example, the side plate may be integrally formed using a metal mold or a casting mold. Alternatively, the bottom of the side plate of a conventional filtration unit may be polished to form an inclined portion or a stepped portion.

[0053] The side plates of the filtration unit of the present invention are not particularly limited as long as they have the bottom shape as described above. Preferably, the side plates have a flat shape. The side plates may have a counterbore or a through-hole for inserting a filtration tube, or may have a hole for lifting and moving the filtration unit.

[0054] The side plates of the filtration unit of the present invention may have legs on their bottom surfaces. In this case, the legs refer to protruding portions extending downward from the bottom surface. The bottom of the side plates of the filtration unit of the present invention contacts the hearth of the filtration device, and the shape of the legs can match the shape of the bottom described above.

[0055] According to one aspect of the present invention, there is provided a molten metal filtering device having an outlet for molten metal, wherein a pair of side plates are arranged so that the longitudinal direction of the filter tube is approximately horizontal, and when the first side plate is located on the left side of the filter tube and the second side plate is located on the right side of the filter tube, the molten metal filtering unit has an inclined portion formed so that the right side bottom edge is positioned vertically higher than the left side bottom edge, the first side plate is arranged so that the first side plate is in contact with the outlet, and the filtering device has a wedge-shaped protrusion on the hearth that has an angle θ2 between the surface that contacts the molten metal filtering unit and the horizontal plane, and the sum of θ1 and θ2 satisfies the range of 61° to 114°.

[0056] Fig. 6 shows an enlarged view of the first side plate of the filtration device and filtration unit of this embodiment. The first side plate 107 is placed on the hearth 201 of the filtration device. The hearth 201 has a wedge-shaped protrusion 601. As shown in Fig. 6, the filtration unit of this embodiment has an inclined portion formed so that the right bottom edge of the first side plate is positioned higher than the left bottom edge. The angle formed by the inclined portion and the vertical direction is defined as θ1.

[0057] The filtration device of this embodiment includes a tap port for molten metal and a wedge-shaped protrusion on the hearth. When the filtration unit is placed in the filtration chamber of the filtration device, the protrusion contacts the bottom of the side plate of the filtration unit. In this case, as shown in FIG. 6 , the angle between the surface contacting the filtration unit and the horizontal plane is θ2, and the sum of θ1 and θ2 can be 61° or more and 114° or less. That is, θ2 may be 1° or more and 54° or less. The sum of θ1 and θ2 may preferably be 75° or more and 110° or less, more preferably 80° or more and 105° or less. When the sum of θ1 and θ2 is within the above range, the filtration unit can be easily positioned so that the first side plate of the filtration unit properly contacts the wall surface of the filtration device on the tap port side when placed in the filtration chamber of the filtration device. Furthermore, untreated molten metal can be prevented from flowing into the tap chamber.

[0058] Although the molten metal filtration unit and filtration device according to the present invention have been described above using specific embodiments, the present invention is not intended to be limited to these embodiments. In particular, it should be noted that the molten metal filtration unit of the present invention can be applied to any molten metal filtration unit as long as it has at least a characteristic bottom shape of the side plate. For example, the filtration unit of the present invention is not limited by the shape, length, number, etc., of the filtration tubes. The filtration unit of the present invention is not limited to the filtration units illustrated in the specific embodiments described above. The scope of the subject matter that can be encompassed by the present invention should be defined by the appended claims.

[0059] <Additional Embodiments Regarding the Structure of the Filter Tube> The structure of the filter tube included in the molten metal filtering unit according to the present invention is not particularly limited except as defined in the appended claims. The filter tube may satisfy specific relationships regarding the inventive shape or dimensions as exemplified in the following items [1] or [2].

[0060] [1] Additional embodiment 1 of filter tubes of molten metal filtration unit An additional example of a molten metal filtration unit includes a filter tube specified as follows: A molten metal filtration unit including: a plurality of cylindrical ceramic filter tubes arranged substantially parallel to each other, each having a substantially circular cross section perpendicular to the longitudinal direction on its outer surface and inner surface, and a pair of side plates disposed at both longitudinal ends of the plurality of ceramic filter tubes, the plurality of ceramic filter tubes having a first end on the side from which the molten metal is discharged and a second end on the other side, and at least some of the plurality of ceramic filter tubes having a longitudinal length L of a portion of the outer surface of the filter tube exposed to the molten metal １ The outer diameter of the filtration tube is D １ The longitudinal length of the part of the inner surface of the filtration tube exposed to the molten metal is L ２ The inner diameter of the filtration tube is D ２ Then, the following two relations are satisfied: (1) L １ / D １ ≧8.5 (2) L ２ / D ２ A molten metal filtration unit that satisfies all of the following requirements:

[0061] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting configurations: (i) In at least some of the plurality of ceramic filter tubes, the inner diameter at the first end is larger than the inner diameter at the second end. (ii) In at least some of the plurality of ceramic filter tubes, the inner diameter at the first end is 100.5% or more and 120% or less of the inner diameter at the second end. (iii) In at least some of the plurality of ceramic filter tubes, the opening shape of the first end encompasses the opening shape of the filter tube-side end of a substantially circular through-hole provided in the side plate on the discharge side of the pair of side plates when viewed in the longitudinal direction. (iv) In the above (iii), the inner diameter of the through-hole in the side plate on the discharge side is smaller than the inner diameter of the filter tube-side end. (v) In the above (iv), the inner diameter of the end of the through hole in the side plate on the melt discharge side is 80% to 99.5% of the inner diameter of the end of the filter tube installation side. (vi) At least some of the plurality of ceramic filter tubes are fitted and fixed at each longitudinal end in a recess formed in the side plate via a packing having a shape that fits the recess. (vii) At least some of the plurality of ceramic filter tubes are formed of a porous material having a porosity of 25% to 50%.

[0062] [2] Additional embodiment 2 of filter tubes of molten metal filtration unit An additional example of a molten metal filtration unit includes a filter tube specified as follows: A molten metal filtration unit including a plurality of cylindrical ceramic filter tubes arranged substantially parallel to each other, each having a substantially circular cross section perpendicular to the longitudinal direction on its outer surface and inner surface, and a pair of side plates arranged at both longitudinal ends of the plurality of ceramic filter tubes, wherein the plurality of ceramic filter tubes have a first end on the side from which the molten metal is discharged and a second end on the other side, and at least some of the plurality of ceramic filter tubes have a longitudinal length L of a portion of the outer surface of the filter tube exposed to the molten metal. １The outer diameter of the filtration tube is D １ The longitudinal length of the part of the inner surface of the filtration tube exposed to the molten metal is L ２ The inner diameter of the filtration tube is D ２ Then, the following two relations are satisfied: (1) L １ / D １ ≧8.5 (2) L ２ / D ２ A molten metal filtration unit that satisfies all of the above requirements.

[0063] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting configurations: (i) In at least some of the plurality of ceramic filter tubes, the inner diameter at the first end is larger than the inner diameter at the second end. (ii) In (i) above, in at least some of the plurality of ceramic filter tubes, the inner diameter at the first end is 100.5% or more and 150% or less of the inner diameter at the second end. (iii) In at least some of the plurality of ceramic filter tubes, the opening shape of the first end encompasses the opening shape of the filter tube-side end of a substantially circular through-hole provided in the side plate on the discharge side of the pair of side plates when viewed in the longitudinal direction. (iv) In (iii) above, in the through-hole in the side plate on the discharge side, the inner diameter at the discharge side end is smaller than the inner diameter at the filter tube-side end. (v) In the above (iv), the inner diameter of the end of the through hole in the side plate on the melt discharge side is 70% to 99.5% of the inner diameter of the end of the filter tube installation side. (vi) At least some of the plurality of ceramic filter tubes are fitted and fixed at each longitudinal end in a recess formed in the side plate via a packing having a shape that fits the recess. (vii) At least some of the plurality of ceramic filter tubes are formed of a porous material having a porosity of 25% to 50%.

[0064] <Additional Embodiments Related to Side Plate Structure> The structure of the pair of side plates included in the molten metal filtration unit according to the present invention is not particularly limited except as defined in the appended claims. These two side plates may have substantially the same external shape, being approximately rectangular parallelepiped plates, or may satisfy specific relationships related to inventive shapes or dimensions, as exemplified in items [1] or [2] below. Furthermore, the shape of the bottom of the side plate of the molten metal filtration unit according to the present invention may also be applied to the legs in the following embodiments.

[0065] [1] Additional embodiment 1 of side plates of molten metal filtration unit An additional example of a molten metal filtration unit includes a pair of side plates specified as follows: A molten metal filtration unit including a pair of side plates and a substantially cylindrical filtration tube connected substantially perpendicularly to each of the pair of side plates, wherein the pair of side plates include a first side plate having a through hole at a location connected to the filtration tube and a second side plate the location connected to the filtration tube is closed, each side plate has at least one leg hanging down from a bottom surface of the side plate, and when the longitudinal direction of the filtration tube is substantially horizontal, the lowest vertical position of the leg of the second side plate is lower than the lowest vertical position of the leg of the first side plate.

[0066] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting configurations: (i) When the longitudinal direction of the filtration tube is approximately horizontal, the ratio of the vertical length of the legs of the first side plate to the vertical length of the legs of the second side plate is 0.20 or more and less than 1.0. (ii) The total ground contact area of ​​all legs in the molten metal filtration unit is 0.015 or more and 0.075 or less relative to the total bottom area of ​​the pair of side plates. (iii) In (ii) above, the total ground contact area of ​​all legs in the molten metal filtration unit is 0.020 or more and 0.060 or less relative to the total bottom area of ​​the pair of side plates. (iv) At least two legs are provided on the first side plate and one leg is provided on the second side plate. (v) In the above (iv), at least two legs are provided near both longitudinal ends of the bottom surface of the first side plate, and one leg is provided at approximately the longitudinal center of the bottom surface of the second side plate.

[0067] [2] Additional embodiment 2 of side plates of molten metal filtration unit An additional example of a molten metal filtration unit includes a pair of side plates specified as follows: A molten metal filtration unit including a pair of side plates and a substantially cylindrical filtration tube connected substantially perpendicularly to each of the pair of side plates, wherein the pair of side plates includes: a first side plate having a through hole at a location connected to the filtration tube, and a second side plate the location connected to the filtration tube is closed, each side plate has a leg extending downward from a bottom surface of the side plate, and the number of legs provided on the first side plate is at least one more than the number of legs provided on the second side plate.

[0068] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting configurations: (i) the first side plate includes two legs and the second side plate includes one leg; (ii) two legs are provided near both longitudinal ends of the bottom surface of the first side plate and one leg is provided approximately in the longitudinal center of the bottom surface of the second side plate; (iii) when the molten metal filtration unit is placed on a horizontal surface and observed vertically from above, the area of ​​the molten metal filtration unit is expressed as the product of the length of the molten metal filtration unit in the longitudinal direction of the filtration tube and the longitudinal length of the side plate, S1 is the area of ​​the molten metal filtration unit, and S2 is the total area of ​​the contact areas of all the legs of the molten metal filtration unit, and the area ratio S2 / S1 is 0.0020 or more and 0.015 or less.

[0069] The filtration unit of the present invention can be easily moved to a predetermined position within the filtration chamber due to the bottom shape of the side plates that make up the filtration unit. Therefore, the filtration unit of the present invention can easily prepare for filtration of molten metal and improves the efficiency of filtering impurities from molten metal such as aluminum, and can be used in various industries that require such filtering work, such as the metal industry and the steel industry.

[0070] 101: Filtration device 102: Inlet port 103: Filtration chamber 104: Filtration unit 105: Tap chamber 106, 110: Tap port 107: First side plate 108: Second side plate 109: Filtration tube 201: Hearth 301: Left side base 302: Right side base 401: First bottom 402: Second bottom 501: First bottom 502: Inclined portion 601: Projection W1: Horizontal length of first bottom W2: Horizontal length of second bottom H2: Vertical length from first bottom to second bottom W1': Horizontal length of first bottom W2': Horizontal length of inclined portion H2': Vertical length from the end of inclined portion in contact with the first bottom to the other end of the inclined portion θ1: Angle between the inclined portion and the vertical direction θ2: Angle between the surface in contact with the molten metal filtration unit and the horizontal plane

Claims

1. A molten metal filtration unit comprising a pair of side plates and a substantially cylindrical filtration tube connected to the pair of side plates substantially perpendicularly, wherein the pair of side plates comprises a first side plate having a through-hole at a location connected to the filtration tube and a second side plate having a closed location connected to the filtration tube, with the longitudinal direction of the filtration tube being substantially horizontal, the first side plate being located on the left side of the filtration tube, and the second side plate being located on the right side of the filtration tube, at least one of the pair of side plates being provided with a bottom portion formed such that either the left bottom side or the right bottom side is positioned higher in the vertical direction than the other bottom side, the molten metal filtration unit.

2. When the longitudinal direction of the filtration tube is substantially horizontal, the first side plate is located on the left side of the filtration tube, and the second side plate is located on the right side of the filtration tube, the first side plate is provided with a bottom portion formed such that either the left bottom side or the right bottom side is positioned higher in the vertical direction than the other bottom side. When the first side plate is provided with a bottom portion formed such that the left bottom side is positioned higher in the vertical direction than the right bottom side, the second side plate is provided with a bottom portion formed such that the left bottom side is positioned higher in the vertical direction than the right bottom side, or when the first side plate is provided with a bottom portion formed such that the right bottom side is positioned higher in the vertical direction than the left bottom side, the second side plate is provided with a bottom portion formed such that the right bottom side is positioned higher in the vertical direction than the left bottom side, the molten metal filtration unit according to claim 1.

3. When the longitudinal direction of the filtration tube is substantially horizontal, the first side plate is located on the left side of the filtration tube, and the second side plate is located on the right side of the filtration tube, at least one of the pair of side plates is provided with a stepped portion formed such that either the left bottom side or the right bottom side is positioned higher in the vertical direction than the other bottom side, the molten metal filtration unit according to claim 1.

4. When the longitudinal direction of the filtration tube is substantially horizontal, the first side plate is located on the left side of the filtration tube, and the second side plate is located on the right side of the filtration tube, the pair of side plates is provided with a stepped portion formed such that the left bottom side is positioned higher in the vertical direction than the right bottom side, the molten metal filtration unit according to claim 3.

5. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the step portion is composed of a first bottom portion which is the lowest portion and a second bottom portion formed to be located higher in the vertical direction than the first bottom portion, and the ratio (W1 / W2) of the horizontal length W1 of the first bottom portion to the horizontal length W2 of the second bottom portion is 0.1 or more and 6.0 or less. However, W1 and W2 are lengths in a direction parallel to the longitudinal direction of the filtering tube. The molten metal filtering unit according to claim 3.

6. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the step portion is composed of a first bottom portion which is the lowest portion and a second bottom portion formed to be located higher in the vertical direction than the first bottom portion, and the ratio (W1 / H2) of the horizontal length W1 of the first bottom portion to the vertical length H2 from the first bottom portion to the second bottom portion is 0.1 or more and 11 or less. However, W1 is a length in a direction parallel to the longitudinal direction of the filtering tube. The molten metal filtering unit according to claim 3.

7. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, at least one of the pair of side plates is formed such that either the left bottom side or the right bottom side is located higher in the vertical direction than the other bottom side, and includes a bottom portion having an inclined portion connecting the first bottom portion which is the lowest portion and the bottom side located higher in the vertical direction than the first bottom portion. The molten metal filtering unit according to claim 1.

8. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the ratio (W1' / W2') of the horizontal length W1' of the first bottom portion to the horizontal length W2' of the inclined portion is 0 or more and 6.0 or less. However, W1' and W2' are lengths in a direction parallel to the longitudinal direction of the filtering tube. The molten metal filtering unit according to claim 7.

9. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the ratio (W1' / H2') of the horizontal length W1' of the first bottom portion to the vertical length H2' from the end portion of the inclined portion in contact with the first bottom portion to the other end portion of the inclined portion is 0 or more and 320 or less, provided that W1' is the length in the direction parallel to the longitudinal direction of the filtering tube. The molten metal filtering unit according to claim 7.

10. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the angle θ1 formed by the inclined portion and the vertical direction is 60° or more and 89° or less. The molten metal filtering unit according to claim 9.

11. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the pair of side plates are formed such that the left bottom side is located higher in the vertical direction than the right bottom side, and includes a bottom portion having a first bottom portion which is the lowest portion and an inclined portion connecting the first bottom portion to the left bottom side. The molten metal filtering unit according to claim 7.

12. When the longitudinal direction of the filtering tube is substantially horizontal, the first side plate is located on the left side of the filtering tube, and the second side plate is located on the right side of the filtering tube, the pair of side plates are formed such that the right bottom side is located higher in the vertical direction than the left bottom side, and includes a bottom portion having a first bottom portion which is the lowest portion and an inclined portion connecting the first bottom portion to the right bottom side. The molten metal filtering unit according to claim 7.

13. A molten metal filtering device having a molten metal outlet, wherein when the pair of side plates has the longitudinal direction of the filter tube substantially horizontal, the first side plate is located on the left side of the filter tube, and the second side plate is located on the right side of the filter tube, the molten metal filtering unit according to claim 10, comprising an inclined portion formed such that the right bottom side is positioned higher in the vertical direction than the left bottom side, the first side plate is arranged to be in contact with the molten metal outlet, the filtering device includes a wedge-shaped protrusion having an angle θ2 formed between a surface in contact with the molten metal filtering unit on the furnace floor and a horizontal plane, and θ2 satisfies that the sum of θ1 and θ2 is 61° or more and 114° or less, the filtering device.

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