Molten metal filtration unit

Abstract

The object of the present invention is to provide a molten metal filtration unit that is easier to arrange at a predetermined position in a filtration chamber compared to conventional molten metal filtration units. The object of the present invention is to provide 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, the pair of side plates including a first side plate having a through hole at a location connected to the filtration tube and a second side plate having a location connected to the filtration tube that is closed, each side plate including at least one leg suspended 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.

Description

[Technical field]

[0001] The present invention relates to a molten metal filtration unit to be disposed in a molten metal filtration apparatus for filtering molten metal such as aluminum, etc. More specifically, the present invention relates to a molten metal filtration unit that facilitates disposing the molten metal filtration unit in a predetermined position in a filtration chamber of a molten metal filtration apparatus. [Background technology]

[0002] Molten metals such as aluminum used in the production of castings usually contain hydrogen and nonmetallic inclusions such as oxides as impurities. For example, hydrogen dissolved in the molten metal forms cavities called porosity in the casting, and oxides and the like can become inclusions in the casting. Both of these cavities and inclusions are undesirable because they can be the starting point for fracture of 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 purpose, a molten metal filtering device is typically used in which a molten metal filtering unit having a plurality of ceramic filtering 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 filtering 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 adopted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-210254 A Summary of the Invention [Problem to be solved by the invention]

[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 or the like. In addition, 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 fine-tune the position of the molten metal filtration unit. Furthermore, in a molten metal filtration device that has been used repeatedly, it is even more difficult to fine-tune the position of the molten metal filtration unit due to friction with the molten metal filtration unit and the influence of distortion of the molten metal filtration device itself caused by repeated expansion and contraction due to the heat of the molten metal.

[0007] Therefore, the problem to be solved by the present invention is to provide a molten metal filtration unit that eliminates the above-mentioned inconveniences, i.e., that is easier to arrange at a predetermined position in a filtration chamber compared to conventional molten metal filtration units. Note that throughout this specification, the "molten metal filtration unit" may also be referred to simply as a "filtration unit." Furthermore, throughout this specification, the "molten metal filtration device" may also be referred to simply as a "filtration device." [Means for solving the problem]

[0008] As a result of intensive research, the inventors have found that the above problem can be solved by improving the legs provided on the bottom surface of the side plate constituting the filtration unit. That is, the inventors have found that by making the lengths of the legs of each side plate different, the operability of moving the filtration unit to a desired position in the filtration chamber and fine-tuning the positioning can be improved due to the weight of the filtration unit itself, that is, due to the imbalance of the weight balance of the filtration unit, and have completed the present invention. In the above description and this specification, the first side plate refers to a side plate having a through hole at the part connected to the filtration tube, and the second side plate refers to a side plate whose part connected to the filtration tube is closed. In this specification, the expression "imbalance of weight balance" of the filtration unit is intended to mean that there is an imbalance in the weight balance in the overall structure or in the weight balance in a partial structure when compared with a filtration unit described later as a typical example.

[0009] A typical embodiment of the present invention is as follows. A pair of side panels; a substantially cylindrical filtration tube connected substantially perpendicularly to each of the pair of side plates; A molten metal filtration unit comprising: The pair of side plates are a first side plate having a through hole at a portion connected to the filtration tube; a second side plate having a portion connected to the filtration tube closed; Each side panel has at least one leg depending from a bottom surface of the side panel; When the longitudinal direction of the filtration tube is substantially horizontal, the lowest position of the leg portion of the second side plate in the vertical direction is lower than the lowest position of the leg portion of the first side plate in the vertical direction. The molten metal filtration unit. Effect of the Invention

[0010] According to the filtration unit of the present invention, when the longitudinal direction of the filtration tube is approximately 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, thereby making it easier to move the filtration unit to a desired position and fine-tune its position within the filtration chamber of the filtration device due to an imbalance in the weight balance, thereby providing an excellent advantage that could not be foreseen from conventional filtration units, which can contribute to improving the efficiency of the entire installation process of the filtration device. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows a typical example of a filtration unit and a filtration device. [Diagram 2] FIG. 2 shows a schematic diagram of a filtration unit according to one embodiment of the present invention. [Diagram 3] FIG. 3 shows a schematic diagram of a first side plate of a filtration unit according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The filtration unit of the present invention is disposed in a filtration chamber of a filtration device for use. In order to facilitate understanding of the characteristics of the filtration unit of the present invention, first, a typical example of the filtration unit and the filtration device will be described with reference to FIG.

[0013] Fig. 1 shows a filtration device 101, which is equipped with an inlet 102, a filtration chamber 103, a discharge chamber 105, and outlets 106 and 110. The filtration unit 104 is equipped with 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 portion connected to the filtration tube 109 closed.

[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 will be described as being observed from the same direction.

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

[0016] In addition, a refractory material made of SiC aggregate bound with Si3N4 can generally be used as the filtering device 101. The size of the filtering device 101 is not particularly limited as long as the filtering unit 104 can be placed in the filtering chamber 103.

[0017] The filtration unit of the present invention is a filtration unit in which each side plate has at least one leg suspended from the bottom surface of the side plate, and when the longitudinal direction of the filtration tube is approximately 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.

[0018] In this type of filtration unit, for example, when the longitudinal direction of the filtration tube is approximately horizontal, the vertical length of the legs provided on the second leg is greater than the vertical length of the legs provided on the first side plate. Hereinafter, unless otherwise specified, the vertical length of the legs provided on each side plate will also be simply referred to as the "leg length."

[0019] The above-mentioned configuration of the filtration unit of the present invention, when placed in the filtration chamber of the filtration device, makes it easy to move the filtration unit to a desired position and fine-tune the placement due to the imbalance of the weight of the filtration unit. More specifically, when the filtration unit of the present invention is placed in a substantially horizontal filtration chamber, the filtration unit is pressed so as to tilt toward the outlet side wall surface (i.e., the first side plate side). As a result, the first side plate and the outlet side wall surface can be easily brought into close contact with each other.

[0020] When filtration of molten metal is repeated, the filtration chamber repeatedly expands and contracts due to the heat of the high-temperature molten metal. In addition, the footrest portion (also called the "base") of the hearth that contacts the filtration unit becomes worn as the filtration unit is repeatedly installed. As a result, the hearth of the filtration device becomes not approximately horizontal due to deterioration over time, making it difficult to place the filtration unit in the filtration chamber. However, the filtration unit of the present invention can easily adhere to the first side plate and the tapping port side wall surface even when placed in a filtration chamber that has deteriorated over time, because pressure is applied to the tapping port side wall surface.

[0021] In one embodiment of the present invention, when the longitudinal direction of the filtration tube is approximately horizontal, the ratio of the vertical length of the leg of the first side plate to the vertical length of the leg of the second side plate may be 0.20 or more and less than 1.0. The length ratio may be preferably 0.4 or more and 0.8 or less, and more preferably 0.5 or more and 0.7 or less.

[0022] When the length ratio is 0.20 or more, the weight balance of the filtration unit is not excessively unbalanced, and an accident caused by the filtration unit tipping over when not in use can be prevented. Also, when the length ratio is less than 1.0, the length of the legs of the first side plate is shorter than the length of the legs of the second side plate, so that when the filtration unit is placed in the filtration chamber, the weight balance of the filtration unit is not unbalanced, and therefore it is easy to move the filtration unit to a desired position and fine-tune its placement.

[0023] The filtration unit of the present invention is characterized by the legs as described above, but the method of forming the legs is not particularly limited. For example, when the legs are formed together with the side plates using a metal mold or a casting mold, the metal mold or casting mold may be adjusted so that the legs have a desired length. In addition, after forming the filtration unit, the legs of the first side plate may be polished or the like so that the length of the legs of the first side plate is shorter than the length of the legs of the second side plate.

[0024] In one embodiment of the present invention, the total ground contact area of ​​all legs in the molten metal filtration unit may be 0.015 to 0.075 relative to the total bottom area of ​​the pair of side plates, and the ratio of these areas may be preferably 0.020 to 0.060, more preferably 0.025 to 0.050.

[0025] When the area ratio is 0.015 or more, the filtration unit can be placed more stably on the legs. When the area ratio is 0.075 or less, the contact area between the filtration unit and the hearth due to the legs is reduced, so that the filtration unit and the hearth can be prevented from sticking to each other.

[0026] The ground contact area of ​​the legs may be calculated from the dimensions of the bottom surfaces of the legs. The ground contact area of ​​the legs may also be measured by applying ink to the legs and measuring ink marks, or by placing the filtration unit on pressure-sensitive paper and measuring marks left behind. The bottom area of ​​the side panels may be calculated from the dimensions of the bottom surfaces of the side panels.

[0027] As described above, in the filtration unit of the present invention, each side plate has at least one leg suspended from the bottom surface of the side plate. The shape, position and number of the leg on the side plate are not particularly limited.

[0028] In one aspect of the present invention, the filtration unit may have at least two legs on the first side plate and one leg on the second side plate. By providing the legs in this manner, even if the filtration unit is placed in a filtration chamber that has deteriorated over time, the filtration unit can be supported at at least three points, allowing the filtration unit to be stably placed.

[0029] In this embodiment, the filtration unit may preferably have at least two legs near both longitudinal ends of the bottom surface of the first side plate and one leg at approximately the longitudinal center of the bottom surface of the second side plate. By providing the legs in this manner, the filtration unit can be more stably disposed.

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment shown in the drawings.

[0031] FIG. 2 shows a filtration unit according to an embodiment of the present invention. However, in order to explain the present invention, FIG. 2 may differ from the actual dimensional ratio and the number of filtration tubes. The filtration unit 104 of the present invention is provided with a leg 201 on the bottom surface of the first side plate 107, and a leg 202 on the bottom surface of the second side plate 108. FIG. 2 illustrates a filtration unit in which the longitudinal direction of the filtration tube is approximately horizontal. In this case, the vertical length H1 of the leg 201 and the vertical length H2 of the leg 202 are different, and the length H2 of the leg 202 is greater than the length H1 of the leg 201. Therefore, the lowest position of the leg 202 is lower than the lowest position of the leg 201. In FIG. 2, the legs 201 and 202 are shown to have a shape inclined toward the first side plate side (the left side of FIG. 2), but the shape of the leg is not particularly limited.

[0032] Therefore, when the filtration unit of the present invention is placed on a substantially horizontal hearth, it tilts toward the first side plate 107. As a result, a pressure is applied to the wall surface on the tap hole side so that the filtration unit tilts toward the first side plate 107, which makes it easier to come into close contact with the wall surface on the tap hole side. The filtration unit of the present invention may also include a packing 203 made of ceramic fiber on the first side plate 107. The pressure applied to the wall surface on the tap hole side causes the packing 203 to come into close contact with the wall surface, which prevents leakage of the molten metal.

[0033] FIG. 3 shows the filtration unit 104 observed from the first side plate 107 side. The filtration unit of the present invention can be easily moved to a desired position and finely adjusted in position, and can be closely attached to the outlet side wall surface. That is, when the filtration unit 104 is placed in the filtration chamber, it can be placed so that pressure is evenly applied to the four corners of the packing 203 (points a, b, c, and d in FIG. 3), so that leakage of the molten metal can be prevented. Whether the pressure is evenly applied to the packing 203 can be judged by measuring the thickness of the packing after compression at four points a, b, c, and d of the packing 203 when the filtration unit 104 is placed in the filtration chamber. The stronger the pressure applied, the more the packing shrinks. Therefore, when pressure is evenly applied to the packing 203, the thickness of the packing after compression at the four points a, b, c, and d will be approximately the same. In the present invention, it is possible to judge whether the pressure applied to the packing is uniform or not from the difference between the point where the thickness of the packing after compression is maximum and the point where the thickness is minimum among the four points a, b, c, and d.

[0034] Although the molten metal filtration unit according to the present invention has been described above with reference to specific embodiments, it is not intended to be limited to these embodiments. In particular, it should be noted that the molten metal filtration unit according to the present invention can be applied to any molten metal filtration unit as long as it has a feature of legs suspended from the bottom of at least a pair of side plates. For example, the filtration unit according to the present invention is not limited by the shape, length, number, etc. of the filtration tubes. The filtration unit according to the present invention is not limited to the filtration unit illustrated in the specific embodiments described above. The scope of the subject matter that can be included in the present invention should be determined by the appended claims.

[0035] <Additional embodiment regarding the structure of the filtration tube> The structure of the filter tube of 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 a specific relationship regarding the inventive shape or dimensions as exemplified in the following items [1] or [2].

[0036] [1].Additional embodiment 1 of the filtration tube of the molten metal filtration unit An additional example of a molten metal filtration unit includes a filtration tube identified as follows: A molten metal filtration unit, comprising: The filter includes a plurality of cylindrical ceramic filter tubes arranged substantially in parallel, 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 ends in the longitudinal direction of the plurality of ceramic filter tubes, The plurality of ceramic filter tubes have a first end on a side from which the molten metal is dispensed and a second end on the other side, At least a portion of the plurality of ceramic filtration tubes are When the longitudinal length of the part of the outer surface of the filter tube exposed to the molten metal is L1, the outer diameter of the filter tube is D1, the longitudinal length of the part of the inner surface of the filter tube exposed to the molten metal is L2, and the inner diameter of the filter tube is D2, the following two relational expressions are satisfied: (1) L1 / D1≧8.5 (2) L2 / D2≦21 A molten metal filtration unit that meets all of the above requirements.

[0037] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting features. (i) At least a portion of the plurality of ceramic filtration tubes have an inner diameter at the first end that is greater than the inner diameter at the second end. (ii) In at least some of the plurality of ceramic filtration tubes, the inner diameter at the first end is not less than 100.5% and not more than 120% of the inner diameter at the second end. (iii) In at least a portion of the plurality of ceramic filter tubes, the opening shape of the first end includes, when viewed in the longitudinal direction, the opening shape of the filter tube-mounted end of a substantially circular through hole provided in the side plate on the hot water outlet side of the pair of side plates. (iv) In the above (iii), the inside diameter of the end of the through hole in the side plate on the molten metal discharge side is smaller than the inside diameter of the end of the through hole on the molten metal discharge side. (v) In the above (iv), the inside diameter of the end of the through hole in the side plate on the discharge side is 80% to 99.5% of the inside diameter of the end of the side where the filtration tube is disposed. (vi) At least some of the plurality of ceramic filter tubes are fixed at their respective longitudinal ends by being fitted into recesses formed in the side plates via packings having a shape that fits into the recesses. (vii) At least a portion of the ceramic filtration tubes is formed from a porous material having a porosity of 25% or more and 50% or less.

[0038] [2].Additional embodiment 2 of the filtration tube of the molten metal filtration unit An additional example of a molten metal filtration unit includes a filtration tube identified as follows: A molten metal filtration unit, comprising: The filter includes a plurality of cylindrical ceramic filter tubes arranged substantially in parallel, 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 ends in the longitudinal direction of the plurality of ceramic filter tubes, The plurality of ceramic filter tubes have a first end on a side from which the molten metal is dispensed and a second end on the other side, At least a portion of the plurality of ceramic filtration tubes are When the longitudinal length of the part of the outer surface of the filter tube exposed to the molten metal is L1, the outer diameter of the filter tube is D1, the longitudinal length of the part of the inner surface of the filter tube exposed to the molten metal is L2, and the inner diameter of the filter tube is D2, the following two relational expressions are satisfied: (1) L1 / D1≧8.5 (2) L2 / D2 ≧ 22 A molten metal filtration unit that meets all of the above requirements.

[0039] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting features. (i) At least a portion of the plurality of ceramic filtration tubes have an inner diameter at the first end that is greater than the inner diameter at the second end. (ii) In the above (i), in at least some of the plurality of ceramic filtration tubes, the inner diameter at the first end is not less than 100.5% and not more than 150% of the inner diameter at the second end. (iii) In at least a portion of the plurality of ceramic filter tubes, the opening shape of the first end includes, when viewed in the longitudinal direction, the opening shape of the filter tube-mounted end of a substantially circular through hole provided in the side plate on the hot water outlet side of the pair of side plates. (iv) In the above (iii), the inside diameter of the end of the through hole in the side plate on the molten metal discharge side is smaller than the inside diameter of the end of the through hole on the molten metal discharge side. (v) In the above (iv), the inside diameter of the end of the through hole in the side plate on the discharge side is 70% or more and 99.5% or less of the inside diameter of the end of the side where the filtration tube is disposed. (vi) At least some of the plurality of ceramic filter tubes are fixed at their respective longitudinal ends by being fitted into recesses formed in the side plates via packings having a shape that fits into the recesses. (vii) At least a portion of the ceramic filtration tubes is formed from a porous material having a porosity of 25% or more and 50% or less.

[0040] <Additional embodiment regarding the structure of the side plate> The structure of the pair of side plates of 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 outer shape, that is, a substantially rectangular parallelepiped plate shape, and may also satisfy a specific relationship regarding the inventive shape or dimensions as exemplified in the following items [1] or [2].

[0041] [1].Additional embodiment 1 of the side plate of the molten metal filtration unit An additional example of a molten metal filtration unit includes a pair of side plates identified as follows: A pair of side panels a substantially cylindrical filtration tube connected substantially perpendicularly to the pair of side plates; A molten metal filtration unit comprising: The pair of side plates are a first side plate having a through hole at a portion connected to the filtration tube; a second side plate having a portion connected to the filtration tube closed; 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 such that either one of a left side bottom edge or a right side bottom edge is positioned vertically higher than the other bottom edge. The molten metal filtration unit.

[0042] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting features. (i) 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, the first side plate has a bottom portion formed such that one of a left side bottom edge and a right side bottom edge is positioned vertically higher than the other bottom edge, When the first side plate has a bottom portion formed such that the left side bottom edge is positioned vertically higher than the right side bottom edge, the second side plate has a bottom portion formed such that the left side bottom edge is positioned vertically higher than the right side bottom edge, or When the first side panel has a bottom portion formed so that the right side bottom edge is positioned vertically higher than the left side bottom edge, the second side panel has a bottom portion formed so that the right side bottom edge is positioned vertically higher than the left side bottom edge. (ii) 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 step portion formed so that either the left side base or the right side base is positioned vertically higher than the other base. (iii) In the above (ii), 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, The pair of side plates have a step portion formed so that the left side base is positioned vertically higher than the right side base. (iv) In the above (ii), 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, the step portion includes a first bottom portion which is the lowest portion and a second bottom portion which is formed so as to be positioned vertically higher than the first bottom portion, The ratio (W1 / W2) of the horizontal length W1 of the first bottom to the horizontal length W2 of the second bottom is 0.1 or more and 6.0 or less, where W1 and W2 are lengths parallel to the longitudinal direction of the filtration tube. (v) In the above (ii), 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, the step portion includes a first bottom portion which is the lowest portion and a second bottom portion which is formed so as to be positioned vertically higher than the first bottom portion, The ratio (W1 / H) of the horizontal length W1 of the first bottom to the vertical length H from the first bottom to the second bottom is 0.1 or more and 11 or less, where W1 is the length in a direction parallel to the longitudinal direction of the filtration tube. (vi) 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 panels is formed so that either the left or right base edge is positioned vertically higher than the other base edge, and is provided with a bottom having a first bottom edge which is the lowest part, and a sloping portion connecting the first bottom edge to the base edge which is positioned vertically higher. (vii) In the above (vi), 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, 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, where W1' and W2' are lengths parallel to the longitudinal direction of the filtration tube. (viii) In the above (vi), 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, The ratio (W1' / H') of the horizontal length W1' of the first bottom to the vertical length H' from the end of the inclined portion that contacts the first bottom to the other end of the inclined portion is greater than or equal to 0 and less than 320, where W1' is the length in a direction parallel to the longitudinal direction of the filtration tube. (ix) In the above (viii), 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, The angle θ1 between the inclined portion and the vertical direction is equal to or greater than 60° and equal to or less than 89°. (x) In the above (vi), 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, The pair of side plates are formed so that the left side base is positioned vertically higher than the right side base, and each side has a bottom having a first bottom portion which is the lowest portion and a sloping portion connecting the first bottom portion to the left side base. (xi) In the above (vi), 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, The pair of side plates are formed so that the right side base is positioned vertically higher than the left side base, and each have a bottom having a first bottom portion which is the lowest part, and a sloping portion connecting the first bottom portion to the right side base. (xii) A molten metal filtering device having a molten metal outlet, The molten metal filtration unit according to the above (ix), in which the pair of side plates are provided with an inclined portion formed such that, 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 right side base is positioned higher in the vertical direction than the left side base, is disposed so that the first side plate is in contact with the tapping port, The filtration device is provided with a wedge-shaped protrusion having an angle θ2 between a surface in contact with the molten metal filtration unit and a horizontal plane on the hearth, and the sum of θ1 and θ2 is 61° or more and 114° or less. The filtration device.

[0043] [2].Additional embodiment 2 of the side plate of the molten metal filtration unit An additional example of a molten metal filtration unit includes a pair of side plates identified as follows: A pair of side panels; a substantially cylindrical filtration tube connected substantially perpendicularly to each of the pair of side plates; A molten metal filtration unit comprising: The pair of side plates are a first side plate having a through hole at a portion connected to the filtration tube; a second side plate having a portion connected to the filtration tube closed; Each side panel has a leg extending downward from the bottom surface of the side panel, The number of legs provided on the first side panel is at least one more than the number of legs provided on the second side panel. The molten metal filtration unit.

[0044] The molten metal filtration unit according to this additional embodiment may further include the following non-limiting features. (i) The first side panel has two legs and the second side panel has one leg. (ii) The first side plate has two legs near both ends in the longitudinal direction of the bottom surface, and the second side plate has one leg approximately in the center in the longitudinal direction of the bottom surface. (iii) When the molten metal filtration unit is placed on a horizontal surface and observed from above, the area of ​​the molten metal filtration unit is represented by 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, and is defined as S1'. The total ground contact area of ​​all the legs of the molten metal filtration unit is S2'. The area ratio S2' / S1' is equal to or greater than 0.0020 and equal to or less than 0.015. EXAMPLES

[0045] The embodiments of the present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

[0046] Filtration units of Examples 1 to 6 and Comparative Example were prepared with the dimensions shown in Table 1. The bottom surface of the side plate of the filtration unit had a long side of 720 mm and a short side of 60 mm (therefore, the total bottom area of ​​the pair of side plates was 86,400 mm). 2In the table, leg heights H1 and H2 are as shown in FIG. 2, where "leg height H1" refers to the vertical length of the leg provided on the bottom surface of the first side panel, and "leg height H2" refers to the vertical length of the leg provided on the bottom surface of the second side panel. The filtration device has a filtration chamber volume of 1.39 m 3 The hearth of the filtration chamber of the filtration device was equipped with a pedestal for the filtration unit, so that the filtration tube was approximately horizontal when the filtration unit was placed. The filtration device used was made of refractory material made of SiC aggregate bonded with Si3N4.

[0047] Molten metal filtering using a filtering unit The following steps (a) to (e) were counted as one filtration operation, and filtration of the molten metal was carried out using the filtration units of Examples 1 to 6 and the Comparative Example. (a) Installation of a filtration unit The filtration unit was placed in the filtration chamber so that the legs of the filtration unit rested on the base in the filtration chamber. The filtration unit was pressed using a pressing jack so that the first side plate of the filtration unit was in close contact with the wall surface of the tap hole side. The filtration unit was fixed by driving a wedge between the second side plate and the wall surface of the filtration device. (b) Preheating the filtration device The filtration device was heated at 80° C. / hour using a temperature-controlled heater installed in the filtration chamber. After the controlled temperature of the temperature-controlled heater reached 800° C., heating by the temperature-controlled heater was continued so as to maintain the controlled temperature at 800° C. Heating by the temperature-controlled heater was continued for 150 hours. (c) Filtration of molten metal 1,000 tons of molten metal at 680℃ to 750℃ was poured into a filtering device and filtered over a period of 14 days. (d) Cooling down of the filtration device The filtration apparatus was allowed to stand until the filtration unit reached room temperature. (e) Removal of the filtration unit The wedge between the second side plate and the wall of the filtration apparatus was removed and the filtration unit was removed from the filtration apparatus.

[0048] Evaluating the ease of placement of filtration units Six workers fixed the filtration unit in the filtration chamber so that the first side plate of the filtration unit was in close contact with the tap-side wall of the filtration chamber, as in step (a) of the above filtration operation. After the filtration unit was fixed, the thickness of the packing was measured at four points a, b, c, and d in Figure 3. The difference between the maximum and minimum thicknesses measured was recorded, and the average value of the six workers was calculated. The average value was used to evaluate the results as follows: A: 1.0mm or less B: 1.0mm or more and 1.5mm or less C: 1.5mm or more and 2.0mm or less D: Greater than 2.0mm

[0049] The ease of placement of the filtration unit was evaluated by the same six workers after the filtration unit was installed in the filtration chamber for the first time (i.e., after step (a) of the first filtration operation) and after the 15th molten metal filtration operation (i.e., after step (a) of the 16th filtration operation).

[0050] The dimensions of the filtration unit and the evaluation results are shown in Table 1. [Table 1] [Industrial Applicability]

[0051] According to the filtration unit of the present invention, the legs provided at the bottom of the side plate constituting the filtration unit allow the filtration unit to be easily moved to a predetermined position within the filtration chamber. Therefore, the filtration unit of the present invention can facilitate preparation for filtration of molten metal, improves the efficiency of filtering impurities from molten metal such as aluminum, and can be used in various industries such as the metal industry and the steel industry where such filtering is required. [Explanation of symbols]

[0052] 101:Filtration device 102: Entrance 103:Filtration chamber 104: Filtration unit 105:Tap Room 106, 110: Tap hole 107:First side plate 108:Second side plate 109: Filtration tube 201: Leg of first side panel 202: Leg of second side panel 203: Packing

Claims

1. A pair of side panels; a substantially cylindrical filtration tube connected substantially perpendicularly to each of the pair of side plates; A molten metal filtration unit comprising: The pair of side plates are a first side plate having a through hole at a portion connected to the filtration tube; a second side plate having a portion connected to the filtration tube closed; Each side panel has at least one leg depending from a bottom surface of the side panel, the leg being integrally formed with the side panel; When the longitudinal direction of the filtration tube is substantially horizontal, the lowest position of the leg portion of the second side plate in the vertical direction is lower than the lowest position of the leg portion of the first side plate in the vertical direction. The molten metal filtration unit.

2. When the longitudinal direction of the filtration tube is approximately horizontal, a ratio of a vertical length of the leg portion of the first side plate to a vertical length of the leg portion of the second side plate is 0.20 or more and less than 1.

0. The molten metal filtration unit according to claim 1.

3. The molten metal filtration unit according to claim 1 , wherein a total ground contact area of ​​all legs in the molten metal filtration unit is 0.015 to 0.075 relative to a total bottom area of ​​the pair of side plates.

4. The molten metal filtration unit according to claim 3 , wherein a 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 a total bottom area of ​​the pair of side plates.

5. At least, the first side panel has two legs and the second side panel has one leg. The molten metal filtration unit according to claim 1.

6. At least two legs are provided near both ends of the bottom surface of the first side plate in the longitudinal direction, and one leg is provided at approximately the center of the bottom surface of the second side plate in the longitudinal direction. The molten metal filtration unit according to claim 5.