Molten metal filter unit

Abstract

The present invention addresses the problem of providing a molten metal filtration unit that is stably disposed in a filtration chamber. This problem is solved by a molten metal filtration unit provided with a pair of side plates and a substantially cylindrical filtration tube that is substantially vertically connected to each of the pair of side plates, the pair of side plates includes a first side plate having a through hole at a portion connected to the filter tube and a second side plate closed at a portion connected to the filter tube, each side plate includes a leg portion vertically disposed from a bottom surface of the side plate, and the number of the leg portions of the first side plate is at least one greater than the number of the leg portions of the second side plate.

Description

Technical Field

[0001] This invention relates to a molten metal filtering unit disposed in a molten metal filtering apparatus for filtering molten metals such as aluminum. More specifically, it relates to a molten metal filtering unit that is easily disposed at a predetermined position within the filter chamber of the molten metal filtering apparatus. Background Technology

[0002] In molten metals such as aluminum used to manufacture castings, non-metallic inclusions such as hydrogen and oxides are commonly found as impurities. For example, dissolved hydrogen in the molten metal can form casting pores, known as gas pores, in the casting. Additionally, oxides and other inclusions can become inclusions in the casting. These casting pores and inclusions can become the starting point for casting failure and are therefore undesirable. Therefore, a filtration device has been developed for filtering molten metal to remove impurities such as inclusions contained within it.

[0003] To achieve this objective, a typical molten metal filtration device is used, wherein a molten metal filtration unit is placed within a filtration chamber, the molten metal filtration unit having multiple ceramic filter tubes for filtering impurities from the molten metal, and the filtration chamber having an inlet and an outlet (see Patent Document 1). In such a molten metal filtration device, when the molten metal filtration unit is placed within the filtration chamber, it is necessary to ensure that the molten metal filtration unit is in close contact with the outlet side of the filtration chamber to prevent leakage of molten metal.

[0004] Therefore, the position and height of the molten metal filter unit can be adjusted as needed by using a block or similar object for adjusting the height of the molten metal filter unit on the furnace bed of the filter chamber.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-210254 Utility Model Content

[0008] The problem to be solved by the utility model

[0009] In a repeatedly used molten metal filtration device, the filter chamber will repeatedly expand and contract due to the heat of the molten metal. Furthermore, the support portion (base portion) in the furnace bed that contacts the filter unit will wear down due to repeated placement of the filter unit. As a result, the furnace bed of the filtration device will become less level over time due to deterioration, making it difficult to stably place the filter unit within the filter chamber.

[0010] Therefore, the problem to be solved by this invention is to provide a molten metal filter unit that eliminates the aforementioned adverse conditions, namely, a molten metal filter unit with stable configuration within the filter chamber. Furthermore, throughout this specification, "molten metal filter unit" is sometimes simply referred to as "filter unit." Additionally, throughout this specification, "molten metal filter device" is sometimes simply referred to as "filter device."

[0011] Methods for solving problems

[0012] The inventors conducted in-depth research and discovered that by improving the legs on the bottom surface of the side plate constituting the filter unit, the aforementioned problems could be solved, thus completing this utility model. Furthermore, in the above description and this specification, the first side plate refers to a side plate with a through hole at the connection point with the filter tube, and the second side plate refers to a side plate whose connection point with the filter tube is closed.

[0013] A typical embodiment of this utility model is described below.

[0014] A molten metal filtration unit, comprising:

[0015] A pair of side panels; and

[0016] A generally cylindrical filter tube that is connected approximately perpendicularly to the pair of side plates;

[0017] The pair of side plates have:

[0018] The first side plate has a through hole at the connection point with the filter tube; and

[0019] The second side plate, at the part where it connects to the filter tube, is sealed;

[0020] Each side panel has legs that hang vertically from the bottom surface of the side panel.

[0021] The first side plate has at least one more leg than the second side plate.

[0022] Effects of the utility model

[0023] According to the filter unit of this invention, by having the first side plate have at least one more leg than the second side plate, a stable configuration of the filter unit can be achieved even in a filter chamber that has deteriorated over the years, through contact between the legs and the furnace bed. Furthermore, because this filter unit allows heat to circulate between the legs, it also provides the added advantage of improved preheating efficiency of the filter device. Attached Figure Description

[0024] Figure 1 This represents a typical example of a filtration unit and filtration device.

[0025] Figure 2 This is a schematic diagram showing a filter unit according to one embodiment of the present invention.

[0026] Figure 3 This is a front view of the first side plate of the filter unit according to one embodiment of the present invention.

[0027] Figure 4 This is a front view of the second side plate of the filter unit according to one embodiment of the present invention.

[0028] Figure 5 This is a graph showing the change of the control temperature of the heater in the preheating evaluation over time, and the change of the temperature of the filter unit in Example 1 and Comparative Example 1 over time. Detailed Implementation

[0029] The filter unit of this invention is configured in the filter chamber of a filter device for use. To facilitate understanding of the features of the filter unit of this invention, firstly, refer to... Figure 1 Typical filtration units and filtration devices are described.

[0030] Figure 1 It is a filter device 101, which includes an inlet 102, a filter chamber 103, an outlet chamber 105, and outlets 106 and 110. The filter unit 104 includes a first side plate 107, a second side plate 108, and a generally cylindrical filter tube 109 connected substantially perpendicularly to the side plates. Furthermore, although in Figure 1 Although not shown in the figure, the first side plate 107 has a through hole at the part where it connects with the filter tube 109, while the part of the second side plate 108 that connects with the filter tube 109 is closed.

[0031] Figure 1 This is a schematic diagram showing the entire filtration device viewed from a direction where the length of the filter tube is set approximately horizontally, with the first side plate located to the left of the filter tube and the second side plate located to the right of the filter tube. In this specification, unless otherwise specified, the filtration unit and filtration device will be described by viewing them from the same direction.

[0032] In molten metal filtration, a filter unit 104 is arranged in a filter chamber 103, and molten metal obtained by melting metals such as aluminum and aluminum alloys is supplied to the inlet 102. The molten metal supplied from the inlet 102 passes through the filter tube 109 of the filter unit 104 arranged in the filter chamber 103, thereby removing impurities such as oxides contained in the molten metal. The filtered molten metal flows from the filter tube 109 through the through hole of the first side plate 107 and flows into the outlet chamber 105 through the outlet 110, and is discharged from the outlet 106 through the outlet chamber 105. The discharged molten metal is sent to a storage device or a metal processing device (not shown) for processing using molten metal.

[0033] Furthermore, the filter device 101 can generally be a filter device made of refractory material made of SiC aggregate bonded with Si3N4. The size of the filter device 101 is not particularly limited as long as it can accommodate the filter unit 104 within the filter chamber 103.

[0034] In the filter unit of this utility model, each side plate has legs hanging from the bottom surface of the side plate, and the number of legs of the first side plate is at least one more than the number of legs of the second side plate.

[0035] As such a filtering unit, examples include: when the second side panel has one leg, the first side panel has two or more legs. Alternatively, examples include: when the second side panel has two legs, the first side panel has three or more legs. Further examples include: when the second side panel has three legs, the first side panel has four or more legs.

[0036] Furthermore, when multiple legs are provided on any one or two side plates, the multiple legs on each side plate are preferably positioned symmetrically with respect to approximately the center point in the length direction of the bottom surface of the side plate. When multiple legs are provided on any one or two side plates, the height (vertical dimension) of the multiple legs on each side plate is preferably approximately the same.

[0037] With respect to the filter unit of this utility model, the above-described structure ensures that even if the furnace bed deforms, the legs of the filter unit can fully contact (or substantially contact) the furnace bed, thus enabling the filter unit to be stably configured within the filter chamber.

[0038] Furthermore, the filtration device needs to be preheated after the filtration unit is installed and before molten metal is added. With the aforementioned structure, the filtration unit of this invention allows heat to circulate between the legs, thus reducing the time to reach the target temperature compared to conventional filtration units and improving preheating efficiency.

[0039] Furthermore, when using a filtration device to filter molten metal, the filter unit of this invention has less friction with the furnace bed compared to conventional filter units, thus making it less likely to hinder the thermal expansion of the filter unit itself. Therefore, it can prevent leakage of molten material caused by cracking of the filter unit due to thermal expansion, and provide high-quality molten metal.

[0040] In one embodiment of this utility model, the filter unit may have two legs on the first side plate and one leg on the second side plate.

[0041] By constructing the filter unit in this way, the filter unit has three legs. Therefore, the bottoms (lowest points in the vertical direction) of the three legs are on the same plane, and even in the filter chamber where the furnace bed has deformed due to years of deterioration, the bottoms of all legs are in contact with the supporting part (base) of the furnace bed. As a result, the filter unit can be stably positioned within the filter chamber.

[0042] In one embodiment of this utility model, the molten metal filtering unit may have two legs near both ends of the bottom surface of the first side plate in the length direction, and one leg approximately at the center of the bottom surface of the second side plate in the length direction.

[0043] By constructing the filter unit in this way, the filter unit can be configured more stably within the filter chamber.

[0044] In one aspect of this utility model, when the molten metal filter unit is placed on a horizontal plane and viewed from above vertically, the area of ​​the molten metal filter unit, which is represented by the product of the length of the molten metal filter unit in the length direction of the filter tube and the length of the side plate, is set as S1, and the total area of ​​the grounding area of ​​all the legs of the molten metal filter unit is set as S2. The area ratio S2 / S1 can be 0.0020 or more and 0.015 or less.

[0045] S1 can be equivalent to the base area when the filter unit is considered as a cuboid. S2 can also be calculated based on the dimensions of the bottom surface of the leg when the bottom of the leg is flat. In addition, the ground contact area of ​​the leg can be measured by applying ink to the leg and measuring the ink stains, or by placing the filter unit on pressure-sensitive paper and measuring the residual marks.

[0046] The area ratio S2 / S1 can be 0.0020 or more and 0.015 or less, preferably 0.0020 or more and 0.0133 or less, and more preferably 0.0020 or more and 0.0093 or less. By keeping the area ratio S2 / S1 within the above range, heat can circulate between each leg, thus reducing the time required to reach the target temperature and improving preheating efficiency.

[0047] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiment shown in the drawings.

[0048] Figure 2 This describes a filter unit according to one embodiment of the present invention. However, Figure 2 Sometimes, for the purpose of illustrating this utility model, the ratio of dimensions and the number of filter tubes may differ from the actual dimensions. The filter unit 104 of this utility model has legs 201 on the bottom surface of the first side plate 107 and legs 202 on the bottom surface of the second side plate 108. Figure 3 This refers to the first side plate of the filter unit according to one embodiment of the present invention. That is, Figure 3 Indicates in Figure 2 The filter unit is observed from the left side of the diagram. Figure 4 This refers to the second side plate of the filter unit according to one embodiment of the present invention. That is, Figure 4 Indicates in Figure 2 The filter unit is observed from the right side of the diagram.

[0049] Therefore, in one aspect of this utility model, it can be as follows: Figure 3 As shown, the first side plate has two legs 201, as Figure 4 As shown, a leg 202 is provided on the second side plate. As previously described, with such a structure, even if the furnace bed is deformed, the legs 201 and 202 of the filter unit can still contact the furnace bed, thus enabling the filter unit 104 to be stably positioned in the filter chamber.

[0050] Furthermore, in this method, heat can be transferred from... Figure 3 Between the two legs 201 and Figure 4 The circulation is on both sides of the leg 202, so compared with the conventional filter unit, the time to reach the target temperature during preheating is shorter, which can improve the preheating efficiency.

[0051] Moreover, in this method, it is possible to... Figure 3 As shown, the first side plate has two legs 201 near both ends along its length on the bottom surface of the first side plate. Figure 4 As shown, a leg 202 is provided approximately at the center of the bottom surface of the second side plate in the longitudinal direction.

[0052] Furthermore, in this method, as mentioned above, the area ratio S2 / S1 can be greater than or equal to 0.0020 and less than or equal to 0.015. Here, when the area S1 of the molten metal filter unit is represented by the product of the length of the molten metal filter unit in the length direction of the filter tube and the length of the side plate, as viewed from above when the molten metal filter unit is placed on a horizontal plane, S1 is... Figure 2 The total length L of the filter unit 104 in the middle is... Figure 3 (or Figure 4 The product of the widths W of the side plates in the figure. When the total area of ​​the grounding area of ​​the legs 201 and 202 is set as S2, S2 can be calculated based on the dimensions of the bottom surfaces of the legs 201 and 202, or the actual grounding area can be measured using ink or pressure-sensitive paper.

[0053] The molten metal filtering unit of this invention has now been described through specific embodiments, but it is not intended to be limited to these embodiments. It is particularly important to note that the molten metal filtering unit of this invention is applicable to any molten metal filtering unit as long as it is characterized at least in the number of legs on the side plates. For example, the filtering unit of this invention is not limited to the shape, length, or number of filter tubes. The shape of the legs is not particularly limited; for example, the bottom surface of the legs can be inclined, or a stepped portion can be provided on the bottom surface of the legs. The filtering unit of this invention is not limited to the filtering unit exemplified in the specific embodiments described above. The scope of the subject matter encompassed by this invention should be determined by the appended claims.

[0054] <Additional implementation methods related to the construction of the filter tube>

[0055] The construction of the filter tube in the molten metal filtering unit of this invention is not particularly limited except as specified in the appended claims. The filter tube can satisfy a carefully designed specific relationship related to shape or size as illustrated in the following items [1] or [2].

[0056] [1] Additional embodiment 1 of filter tube for molten metal filter unit

[0057] As an additional example of a molten metal filtration unit, a molten metal filtration unit having a filter tube defined as follows can be listed.

[0058] A molten metal filtration unit, wherein,

[0059] The molten metal filtration unit comprises multiple cylindrical ceramic filter tubes and a pair of side plates. The multiple ceramic filter tubes are arranged in approximately parallel directions, and the cross-sectional shapes of their outer and inner surfaces perpendicular to the length direction are approximately circular. The pair of side plates are disposed at both ends of the multiple ceramic filter tubes along their length direction.

[0060] The plurality of ceramic filter tubes have a first end on one side for molten metal to flow out and a second end on the other side.

[0061] With regard to at least a portion of the plurality of ceramic filter tubes,

[0062] When the length of the portion of the filter tube's outer surface exposed to the molten metal is defined as L1, the outer diameter of the filter tube as D1, the length of the portion of the filter tube's inner surface exposed to the molten metal as L2, and the inner diameter of the filter tube as D2,

[0063] The following two relations must be satisfied:

[0064] (1) L1 / D1 ≥ 8.5

[0065] (2) L2 / D2≤21.

[0066] The molten metal filtering unit of this additional embodiment may also include the following non-limiting structures.

[0067] (i)

[0068] In at least a portion of the plurality of ceramic filter tubes, the inner diameter at the first end is larger than the inner diameter at the second end.

[0069] (ii)

[0070] In at least a portion of the plurality of ceramic filter tubes, the inner diameter at the first end is more than 100.5% and less than 120% of the inner diameter at the second end.

[0071] (iii)

[0072] In at least a portion of the plurality of ceramic filter tubes, the opening shape of the first end, when viewed from the longitudinal direction, covers the opening shape of the filter tube end with a generally circular through hole on the liquid outlet side of the pair of side plates.

[0073] (iv)

[0074] In (iii) above, the inner diameter of the end of the side plate on the liquid outlet side is smaller than the inner diameter of the end of the side plate on the filter tube side.

[0075] (v)

[0076] In (iv) above, the inner diameter of the liquid outlet end of the through hole in the side plate on the liquid outlet side is more than 80% and less than 99.5% of the inner diameter of the end of the filter tube.

[0077] (vi)

[0078] At least a portion of the plurality of ceramic filter tubes are fitted and fixed to the recesses in the side plate at their respective ends along the length direction via pads having a shape that matches the recesses.

[0079] (vii)

[0080] At least a portion of the plurality of ceramic filter tubes are formed of a porous material having a porosity of more than 25% and less than 50%.

[0081] [2] Additional embodiment 2 of the filter tube of the molten metal filter unit

[0082] As an additional example of a molten metal filtration unit, a molten metal filtration unit having a filter tube defined as follows can be listed.

[0083] A molten metal filtration unit, wherein,

[0084] The molten metal filtration unit comprises multiple cylindrical ceramic filter tubes and a pair of side plates. The multiple ceramic filter tubes are arranged in approximately parallel directions, and the cross-sectional shapes of their outer and inner surfaces perpendicular to the length direction are approximately circular. The pair of side plates are disposed at both ends of the multiple ceramic filter tubes along their length direction.

[0085] The plurality of ceramic filter tubes have a first end on one side for molten metal to flow out and a second end on the other side.

[0086] With regard to at least a portion of the plurality of ceramic filter tubes,

[0087] When the length of the portion of the filter tube's outer surface exposed to the molten metal is defined as L1, the outer diameter of the filter tube as D1, the length of the portion of the filter tube's inner surface exposed to the molten metal as L2, and the inner diameter of the filter tube as D2,

[0088] The following two relations must be satisfied:

[0089] (1) L1 / D1 ≥ 8.5

[0090] (2) L2 / D2≥22.

[0091] The molten metal filtering unit of this additional embodiment may further have the following non-limiting structure.

[0092] (i)

[0093] In at least a portion of the plurality of ceramic filter tubes, the inner diameter at the first end is larger than the inner diameter at the second end.

[0094] (ii)

[0095] In (i) above, in at least a portion of the plurality of ceramic filter tubes, the inner diameter at the first end is more than 100.5% and less than 150% of the inner diameter at the second end.

[0096] (iii)

[0097] In at least a portion of the plurality of ceramic filter tubes, the opening shape of the first end, when viewed from the longitudinal direction, covers the opening shape of the filter tube end with a generally circular through hole on the liquid outlet side of the pair of side plates.

[0098] (iv)

[0099] In (iii) above, the inner diameter of the end of the side plate on the liquid outlet side is smaller than the inner diameter of the end of the side plate on the filter tube side.

[0100] (v)

[0101] In (iv) above, the inner diameter of the liquid outlet end of the through hole in the side plate on the liquid outlet side is more than 70% and less than 99.5% of the inner diameter of the end of the filter tube.

[0102] (vi)

[0103] At least a portion of the plurality of ceramic filter tubes are fitted and fixed to the recesses in the side plate at their respective ends along the length direction via pads having a shape that matches the recesses.

[0104] (vii)

[0105] At least a portion of the plurality of ceramic filter tubes are formed of a porous material having a porosity of more than 25% and less than 50%.

[0106] <Additional implementation methods related to the construction of the side panels>

[0107] The construction of the pair of side plates in the molten metal filtering unit of this invention is not particularly limited except as specified in the appended claims. In addition to having substantially the same shape, each side plate being generally rectangular, the two side plates may also satisfy a carefully designed specific relationship related to shape or size as illustrated in the following items [1] or [2].

[0108] [1] Additional embodiment 1 of the side plate of the molten metal filter unit

[0109] As an example of an additional molten metal filtering unit, a molten metal filtering unit having a pair of side plates defined as follows can be listed.

[0110] A molten metal filtration unit, comprising:

[0111] A pair of side panels; and

[0112] A generally cylindrical filter tube connected substantially perpendicularly to the pair of side plates;

[0113] The pair of side plates include:

[0114] The first side plate has a through hole at the connection point with the filter tube; and

[0115] The second side plate, at the part where it connects to the filter tube, is closed;

[0116] With the length of the filter tube set to approximately horizontal, and the first side plate positioned to the left of the filter tube and the second side plate positioned to the right of the filter tube,

[0117] At least one of the pair of side panels has a bottom formed in such a way that either the left or right bottom edge is set higher in the vertical direction than the bottom edge of the other side.

[0118] The molten metal filtering unit of this additional embodiment may further have the following non-limiting structure.

[0119] (i)

[0120] With the length of the filter tube set to approximately horizontal, and the first side plate positioned to the left of the filter tube and the second side plate positioned to the right of the filter tube,

[0121] The first side panel has a bottom formed in such a way that either the left or right bottom edge is set higher in the vertical direction than the other bottom edge.

[0122] When the first side panel has a bottom formed in such a way that the left bottom edge is higher than the right bottom edge in the vertical direction, the second side panel also has a bottom formed in such a way that the left bottom edge is higher than the right bottom edge in the vertical direction, or...

[0123] When the first side panel has a bottom formed in such a way that the right bottom edge is set higher than the left bottom edge in the vertical direction, the second side panel has a bottom formed in such a way that the right bottom edge is set higher than the left bottom edge in the vertical direction.

[0124] (ii)

[0125] With the length of the filter tube set to approximately horizontal, and the first side plate positioned to the left of the filter tube and the second side plate positioned to the right of the filter tube,

[0126] At least one of the pair of side panels has a stepped portion formed in such a way that either the left or right bottom edge is set higher in the vertical direction than the bottom edge of the other side.

[0127] (iii)

[0128] In the above (ii), when the length direction of the filter tube is set to be approximately 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,

[0129] The pair of side plates have a stepped portion formed in such a way that the left bottom edge is set higher than the right bottom edge in the vertical direction.

[0130] (iv)

[0131] In the above (ii), when the length direction of the filter tube is set to be approximately 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,

[0132] The stepped portion is composed of a first bottom portion as the lowest point and a second bottom portion formed in a manner that is higher than the first bottom portion in the vertical direction.

[0133] 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, wherein W1 and W2 are lengths in directions parallel to the length direction of the filter tube.

[0134] (v)

[0135] In the above (ii), when the length direction of the filter tube is set to be approximately 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,

[0136] The stepped portion is composed of a first bottom portion as the lowest point and a second bottom portion formed in a manner that is higher than the first bottom portion in the vertical direction.

[0137] 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 is 0.1 or more and 11 or less, wherein W1 is the length in the direction parallel to the length direction of the filter tube.

[0138] (vi)

[0139] With the length of the filter tube set to approximately horizontal, and the first side plate positioned to the left of the filter tube and the second side plate positioned to the right of the filter tube,

[0140] At least one of the pair of side plates has a bottom, which is formed such that either the left bottom edge or the right bottom edge is set higher in the vertical direction than the bottom edge of the other side, and has a first bottom as the lowest part and an inclined part connecting the first bottom to the bottom edge set higher in the vertical direction.

[0141] (vii)

[0142] In the above (vi), when the length direction of the filter tube is set to be approximately 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,

[0143] The ratio (W1' / W2') of the horizontal length W1' of the first bottom to the horizontal length W2' of the inclined portion is 0 or more and 6.0 or less, wherein W1' and W2' are lengths in directions parallel to the length direction of the filter tube.

[0144] (viii)

[0145] In the above (vi), when the length direction of the filter tube is set to be approximately 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,

[0146] 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 is 0 or more and 320 or less, wherein W1' is the length in the direction parallel to the length direction of the filter tube.

[0147] (ix)

[0148] In the above (viii), when the length direction of the filter tube is set to be approximately 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,

[0149] The angle θ1 formed by the inclined portion and the vertical direction is 60° or more and 89° or less.

[0150] (x)

[0151] In the above (vi), when the length direction of the filter tube is set to be approximately 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,

[0152] The pair of side plates have a bottom, which is formed such that the left bottom edge is set higher in the vertical direction than the right bottom edge, and has a first bottom as the lowest part and an inclined part connecting the first bottom to the left bottom edge.

[0153] (xi)

[0154] In the above (vi), when the length direction of the filter tube is set to be approximately 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,

[0155] The pair of side plates have a bottom, which is formed such that the right bottom edge is set higher in the vertical direction than the left bottom edge, and has a first bottom as the lowest part and an inclined part connecting the first bottom to the right bottom edge.

[0156] (xii)

[0157] A molten metal filtration device includes a molten metal outlet, wherein...

[0158] Regarding the molten metal filtration unit described above (ix), in which the pair of side plates are arranged such that the length direction of the filter tube is approximately 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, and the right bottom edge is set higher than the left bottom edge in the vertical direction, the first side plate is arranged in contact with the liquid outlet.

[0159] The filtering device has a wedge-shaped protrusion on the furnace bed, the wedge-shaped protrusion having an angle θ2 between the surface of the surface that contacts the molten metal filtering unit and the horizontal plane, θ2 satisfying that the sum of θ1 and θ2 is more than 61° and less than 114°.

[0160] [2] Additional Embodiment 2 of Molten Metal Filtering Unit

[0161] As an example of an additional molten metal filtering unit, a molten metal filtering unit having a pair of side plates defined as follows can be listed.

[0162] A molten metal filtration unit, comprising:

[0163] A pair of side panels; and

[0164] A generally cylindrical filter tube that is connected approximately perpendicularly to the pair of side plates;

[0165] The pair of side plates include:

[0166] The first side plate has a through hole at the connection point with the filter tube; and

[0167] The second side plate, at the part where it connects to the filter tube, is closed;

[0168] Each side panel has at least one leg that hangs vertically from the bottom surface of the side panel.

[0169] With the length direction of the filter tube 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.

[0170] The molten metal filtering unit of this additional embodiment may further have the following non-limiting structure.

[0171] (i)

[0172] With the length direction of the filter tube 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 is 0.20 or more and less than 1.0.

[0173] (ii)

[0174] The sum of the grounding areas of all the legs in the molten metal filter unit is greater than 0.015 and less than 0.075 relative to the sum of the bottom areas of the pair of side plates.

[0175] (iii)

[0176] In (ii) above, the sum of the grounding areas of all the legs in the molten metal filter unit is greater than 0.020 and less than 0.060 relative to the sum of the bottom areas of the pair of side plates.

[0177] (iv)

[0178] It has at least two legs on the first side plate and one leg on the second side plate.

[0179] (v)

[0180] In (iv) above, 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.

[0181]

Example

[0182] 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.

[0183] The filter units of Examples 1-5 and Comparative Examples 1-5 were manufactured according to the dimensions and the number of legs and filter tubes shown in Table 1. Furthermore, the total length of the filter unit varies depending on the length of the filter tubes constituting the filter unit; the total length L of the filter unit is... Figure 2 The L in the figure corresponds to the side panel width W and Figure 3 or Figure 4The W in the figure corresponds to this. In Examples 1-5, the number of legs was used to indicate that the first side plate has two legs and the second side plate has one leg. In Comparative Examples 1-5, the number of legs was used to indicate that the first side plate has two legs and the second side plate has two legs.

[0184] The filtration device uses a filter chamber with a volume of 1.39m³. 3 The filter device has a base corresponding to the number of legs of the filter unit installed on the furnace bed in the filter chamber. The filter device uses a refractory made of SiC aggregate bonded with Si3N4.

[0185] Molten metal filtration operation of the filtration unit

[0186] The following steps (a) to (e) were performed as a single filtration operation, and the filtration units of Examples 1 to 5 and Comparative Examples 1 to 5 were used to filter molten metal.

[0187] (a) Setting of the filter unit

[0188] The filter unit is positioned within the filter chamber with its legs resting on a base. A jack is used to press the filter unit firmly against the outlet side wall. The filter unit is then secured by inserting wedges between the second side plate and the filter unit wall.

[0189] (b) Preheating of the filtration unit

[0190] The filter unit was heated at 80°C / hour using a temperature-controlled heater located within the filter chamber. After the temperature-controlled heater reached 800°C, heating continued to maintain the controlled temperature at 800°C. Heating continued until the temperature sensor located on the bottommost filter tube in the filter unit reached 700°C.

[0191] (c) Filtration of molten metal

[0192] 1000t of molten metal at 680℃~750℃ was fed into the filtration device and filtered for 14 days.

[0193] (d) Cooling of the filtration device

[0194] The temperature sensor on the bottom filter tube of the filter unit is placed to reach room temperature.

[0195] (e) Removal of the filter unit

[0196] The wedge between the second side plate and the wall of the filter device was removed, and the filter unit was removed from the filter device.

[0197] Evaluation of the configuration stability of the filter unit

[0198] The stability of the filter unit configuration was evaluated by inserting feeler gauges between the legs of the filter unit and the base. Feeler gauges were inserted between each leg and the base of the filter chamber in the aforementioned filtration operation, after step (a) and before step (b). The stability of the filter unit configuration was evaluated based on the value of the feeler gauge indicating the maximum gap between each leg and the base of the filter chamber, as follows.

[0199] A: Less than 0.5mm (a 0.5mm feeler gauge was not inserted into any of the legs).

[0200] B: 0.5mm or more and less than 2.0mm (a 0.5mm feeler gauge was inserted into one or more legs, but not a 2.0mm feeler gauge).

[0201] C: 2.0mm or more (a 2.0mm feeler gauge was inserted into one or more legs).

[0202] The evaluation of the configuration stability of the filter unit was carried out after the filter unit was initially installed in the filter chamber (i.e., after step (a) of the first filtration operation), after the 15th filtration operation (i.e., after step (a) of the 16th filtration operation), and after the 30th filtration operation (i.e., after step (a) of the 31st filtration operation).

[0203] Evaluation of the preheating performance of the filter device

[0204] To eliminate the effects of years of deterioration in the filtration unit, the preheating performance of the filtration unit was evaluated by measuring the temperature change of the filtration unit over time in step (b) of the first filtration operation. Specifically, in step (b) of the first filtration operation, the time it took for the temperature sensor installed on the bottommost filter tube of the filtration unit to reach 500°C was measured. Figure 5 The changes in the control temperature of the temperature-controlled heater over time and the changes in the temperature of the filter unit in Example 1 and Comparative Example 1 over time are shown. For the filter units in Examples 1-5 and Comparative Examples 1-5, the preheating performance of the filter device was evaluated based on the temperature changes over time as follows.

[0205] A: The time required to reach 500℃ is less than 80 hours.

[0206] B: The time required to reach 500℃ is more than 80 hours but less than 85 hours.

[0207] C: The time required to reach 500℃ is more than 85 hours.

[0208] The dimensions and evaluation results of the filter unit are shown in Table 1.

[0209] Table 1

[0210]

[0211] Industrial applicability

[0212] According to the filter unit of this invention, by optimizing the relationship between the number of legs provided on the two side plates, a stable configuration within the filter chamber that has deteriorated over the years and an improvement in the preheating efficiency of the filter device can be achieved. Therefore, the filter unit of this invention can easily prepare for molten metal filtration, thereby improving operational efficiency when filtering impurities from molten metals such as aluminum. Thus, it can be used in various industries such as the metal industry and the steel industry where such filtration operations are required.

[0213] Explanation of reference numerals in the attached figures

[0214] 101: Filtration device

[0215] 102: Liquid Inlet

[0216] 103: Filter Chamber

[0217] 104: Filter Unit

[0218] 105: Discharge Chamber

[0219] 106, 110: liquid outlet

[0220] 107: First side panel

[0221] 108: Second side panel

[0222] 109: Filter tube

[0223] 201: Legs of the first side plate

[0224] 202: Legs of the second side panel

Claims

1. A molten metal filtering unit, comprising: A pair of side panels; and A generally cylindrical filter tube that is connected approximately perpendicularly to the pair of side plates; Its features are, The pair of side plates include: The first side plate has a through hole at the connection point with the filter tube; and The second side plate, at the part where it connects to the filter tube, is sealed; Each side panel has legs that hang vertically from the bottom surface of the side panel. The first side plate has at least one more leg than the second side plate. When the molten metal filter unit is placed on a horizontal plane and viewed from above vertically, the area of ​​the molten metal filter unit, represented by the product of the length of the molten metal filter unit in the length direction of the filter tube and the length of the side plate, is defined as S1. Let the total grounding area of ​​all legs of the molten metal filter unit be S2. The area ratio S2 / S1 is above 0.0020 and below 0.

015.

2. The molten metal filtering unit according to claim 1, characterized in that, The first side panel has two legs, and the second side panel has one leg.

3. The molten metal filtering unit according to claim 1, characterized in that, Two legs are provided near the two 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.

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