Baffle plate for water heating apparatus

Abstract

A baffle plate inserted into a tube of a water heater for heating water according to the present invention comprises: a body portion formed as a plate extending along the vertical direction and perpendicular to the vertical direction, and inserted into the tube, wherein the direction in which the tube extends is called the vertical direction and a direction perpendicular to the vertical direction is called the front-rear direction; a plurality of through holes penetrating the body portion and arranged along the vertical direction; and a plurality of protruding pieces protruding along the front-rear direction from a portion of the circumference of the plurality of through holes, wherein some of the protruding pieces protruding along the front-rear direction from the upper end of the plurality of through holes are a plurality of first protruding pieces, and other protruding pieces protruding along the front-rear direction from the lower end of the plurality of through holes are second protruding pieces.

Description

Technology Field

[0001] The present invention relates to a baffle plate for a water heater. Background Technology

[0002] Water heaters, which heat water for draining or heating purposes, generally achieve their intended purpose by injecting fuel, burning it, and transferring the resulting heat to the water.

[0003] In order to transfer heat generated from a heat source contained in the water heater to the water, a heat exchanger may be formed in the water heater. Among various types of heat exchangers, a heat exchanger may be used in which combustion gas formed by heating is flowed through a flue, and as the flue is heated by the heat of the combustion gas, heat is transferred to the heating water flowing around the flue.

[0004] Meanwhile, a baffle plate that forms a flow of combustion gas may be placed inside the flue to increase the heat exchange efficiency between the heating water and the combustion gas. The baffle plate may be formed in a shape that obstructs or allows the flow of combustion gas so that the combustion gas flows into every corner of the flue as much as possible to exchange heat with the heating water.

[0005] The baffle plate needs to be designed to minimize the occurrence of flow stagnation zones within the flue where the flow of combustion gases becomes stagnant. If a flow stagnation zone occurs, some combustion gases remain in that area, while high-temperature combustion gases are discharged without sufficiently transferring heat to the heating water, potentially resulting in high-temperature combustion gases being released from the water heater. Therefore, the heat exchange efficiency of the water heater may decrease if a flow stagnation zone occurs. Additionally, the pressure drop of the combustion gases passing through the flue may increase when a flow stagnation zone occurs. The problem to be solved

[0006] The present invention has been devised to solve such problems and provides a baffle plate for a water heater capable of reducing the occurrence of a flow stagnation region. means of solving the problem

[0007] A baffle plate inserted into a tube of a water heater for heating water according to an embodiment of the present invention comprises: a body portion formed as a plate extending along the vertical direction and perpendicular to the vertical direction, and inserted into the tube, wherein the direction in which the tube extends is called the vertical direction and a direction perpendicular to the vertical direction is called the front-rear direction; a plurality of through holes penetrating the body portion and arranged along the vertical direction; and a plurality of protruding pieces protruding along the front-rear direction from a portion of the circumference of the plurality of through holes, wherein some of the protruding pieces protruding along the front-rear direction from the upper end of the plurality of through holes are a plurality of first protruding pieces, and other protruding pieces protruding along the front-rear direction from the lower end of the plurality of through holes are second protruding pieces. Effects of the invention

[0008] Accordingly, the occurrence of fluid stagnation regions within the pipes can be reduced, thereby increasing the heat exchange efficiency of the water heater. Brief explanation of the drawing

[0009] Figure 1 is a conceptual diagram of an exemplary water heater. FIG. 2 is a perspective view of an exemplary baffle plate. FIG. 3 is a drawing showing a linkage and a baffle plate according to one embodiment of the present invention inserted therein. FIG. 4 is a perspective view of a baffle plate according to one embodiment of the present invention. FIG. 5 is a perspective view of a baffle plate according to one embodiment of the present invention, viewed from the rear toward the front. FIG. 6 is a perspective view of a baffle plate according to one embodiment of the present invention, viewed from right to left. FIG. 7 is a bottom view of a baffle plate according to one embodiment of the present invention. FIG. 8 is a plan view of a baffle plate according to one embodiment of the present invention. FIG. 9 is a perspective view showing a baffle plate according to a modified example of an embodiment of the present invention. FIG. 10 is a perspective view showing a baffle plate according to another variation of one embodiment of the present invention. FIG. 11 is an enlarged view of a part of the structure of a baffle plate according to a modified example of an embodiment of the present invention. Figure 12 is a diagram showing the flow velocity profile of combustion gases occurring within a pipe when an exemplary baffle plate is inserted into the pipe. FIG. 13 is a diagram showing the flow velocity profile of combustion gas occurring within a pipe when a baffle plate according to one embodiment of the present invention is inserted into a pipe. Specific details for implementing the invention

[0010] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0011] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms. Where it is stated that a component is "connected," "combined," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but that another component may also be "connected," "combined," or "connected" between each component.

[0012] FIG. 1 is a conceptual diagram of an exemplary water heater (100). FIG. 2 is a perspective view of an exemplary baffle plate (1).

[0013] Referring to FIGS. 1 and 2, an exemplary water heater (100) is a device that generates heat from a heat source and then heats heating water through heat exchange between the combustion gas generated therefrom and the heating water. The water heater (100) may include a case (101) containing other components, a burner (102), a flue (103), and a baffle plate (104). A combustion chamber (106) may be provided inside the case (101), and a burner (102) may be placed in the combustion chamber (106) to generate heat and combustion gas through a combustion reaction. The combustion chamber (106) may be connected to one end of the flue (103), and a hollow (105) through which heating water flows may be formed around the combustion chamber (106) and the connection. While the combustion gas generated in the combustion chamber (106) is discharged through the flue (103) to the other end of the flue (103), the heating water flowing in the hollow (105) around the flue (103) and the combustion chamber (106) can be heated and discharged by receiving heat from the combustion gas.

[0014] The flue (103) may be extended along the vertical direction of FIG. 1, and water may flow through it. An exemplary baffle plate (104) may be placed inside the flue (103). By placing the baffle plate (104), a path for the combustion gas flowing within the flue (103) may be determined.

[0015] The flue (103) is a component configured to allow combustion gas to flow inside, and as illustrated, a plurality of flues may be arranged in the water heater (100). A baffle plate (104) is inserted into the flue (103). One end of the flue (103) may be connected to the combustion chamber (106). The flue (103) may be arranged across the hollow (105) so that the other end of the flue (103) discharges combustion gas to the outside. One end of the flue (103) may be a lower end located on the lower side, and the other end may be an upper end located on the upper side.

[0016] A burner (102) is configured to cause a combustion reaction between air and fuel. Accordingly, the burner (102) may include a fuel nozzle that sprays fuel and a blower that pumps air. The ends of the fuel nozzle and the blower are located in a combustion chamber (106) so that a combustion reaction can occur in the combustion chamber (106).

[0017] An exemplary baffle plate (104) may include a plurality of through holes (1042) formed by penetrating a body portion (1041) as illustrated, and a plurality of protruding pieces (1043) of the same shape protruding around the plurality of through holes (1042). However, the direction in which the protruding pieces (1043) protrude may be two: one direction and the opposite direction. However, the protruding pieces (1043) protruding around one through hole (1042) may protrude in the same direction.

[0018] FIG. 3 is a drawing showing a linkage (103) and a baffle plate (1) according to an embodiment of the present invention inserted therein. FIG. 4 is a perspective view of a baffle plate (1) according to an embodiment of the present invention. FIG. 5 is a perspective view of a baffle plate (1) according to an embodiment of the present invention viewed from the rear toward the front. FIG. 6 is a perspective view of a baffle plate (1) according to an embodiment of the present invention viewed from the right toward the left. FIG. 7 is a bottom view of a baffle plate (1) according to an embodiment of the present invention. FIG. 8 is a top view of a baffle plate (1) according to an embodiment of the present invention.

[0019] According to one embodiment of the present invention, a baffle plate (1) provided to be inserted into a tube (103) includes a body portion (11), a through hole (12), and a protruding piece (13). In the specification of the present invention, the direction in which the tube (103) extends is called the up-down direction, a direction orthogonal to the up-down direction is called the front-back direction, and a direction orthogonal to both the up-down direction and the front-back direction is called the left-right direction. These definitions of directions are used exemplarily to describe a water heater (100) and a baffle plate (1) located inside it, and may change depending on the arrangement of the water heater (100) or the baffle plate (1). A baffle plate (1) according to one embodiment of the present invention may be used in an exemplary water heater (100) to form a water heater according to one embodiment of the present invention.

[0021] Body part (11)

[0022] The body portion (11) is a part formed as a plate that extends along the vertical direction and is orthogonal to the front and rear directions. The body portion (11) can be inserted into the coupling member (103). On the upper end (111) of the body portion (11), a protrusion (14) can be formed protruding along the left and right directions so that when the baffle plate (1) is inserted into the coupling member (103), it catches on the upper end of the coupling member (103) to prevent the baffle plate (1) from falling downward. The catch portion can be formed by partially cutting the upper end (111) of the body portion (11) to form an opening (15) and bending it along the left and right directions, but the method of formation is not limited thereto. The catch portion can be composed of two parts protruding to the left and right respectively as illustrated, but the number is not limited thereto.

[0024] through hole (12)

[0025] The through hole (12) is an opening formed to allow combustion gas to enter and exit through the body part (11), and may be formed in multiple numbers and arranged one by one at predetermined intervals along the vertical direction. The through hole (12) may have a rectangular shape as shown in the illustration, but its shape is not limited thereto.

[0026] The upper (121) and lower ends of the through hole (12) may be extended along the left-right direction. The left and right ends of the through hole (12) may be extended along the up-down direction. These left and right ends of the upper and lower ends may be connected to the left and right ends of the through hole (12) to form the rectangular perimeter of the through hole (12).

[0028] Protruding piece (13)

[0029] The protruding part (13) refers to a portion that protrudes along the front-rear direction from a part of the circumference of the through hole (12). The protruding part (13) may be composed of multiple parts. The protruding part (13) may protrude from the top (121) and bottom of the through hole (12).

[0030] Let some of the protruding pieces (13) that protrude along the front-rear direction from the upper end (121) of the through hole (12) be called the first protruding piece (131). Also, let other protruding pieces (13) that protrude along the front-rear direction from the lower end (122) of the through hole (12) be called the second protruding piece (132).

[0031] The first protruding piece (131) and the second protruding piece (132) may each have a shape corresponding to at least a part of the first part and at least a part of the second part when the shape corresponding to the shape of the through hole (12) is divided into two parts including the first part and the second part. That is, the sum of the area of ​​the first protruding piece (131) and the area of ​​the second protruding piece (132) may be less than or equal to the area of ​​the through hole (12).

[0032] The first protruding piece (131) may have a shape corresponding to the first part, and the second protruding piece (132) may have a shape corresponding to the second part. In this case, the sum of the area of ​​the first protruding piece (131) and the area of ​​the second protruding piece (132) may be equal to the area of ​​the through hole (12). In this case, when the first protruding piece (131) and the second protruding piece (132) are separated from the body part (11) and combined, a shape similar to the through hole (12) can be formed.

[0033] Based on the front-rear direction, the outer end of the first protruding piece (131) and the outer end of the second protruding piece (132) can be formed in shapes corresponding to each other. If the first protruding piece (131) and the second protruding piece (132) each have shapes corresponding to the first part and the second part, respectively, then the first protruding piece (131) and the second protruding piece (132) can be separated from the body part (11) and combined to form a shape such as a through hole (12). In this case, since there is no need to divide the first part and the second part and perform additional cutting to form each protruding piece (131, 132), each protruding piece (131, 132) can be formed with the initial cutting, thus reducing material waste during the manufacturing process and simplifying the manufacturing process.

[0034] The first protruding piece (131) and the second protruding piece (132) may have different shapes. Based on the front-rear direction, the outer end of the first protruding piece (131) may have a shape that protrudes outwardly in a convex manner. The outer end of the second protruding piece (132) may have a shape that is concavely sunken inward.

[0035] Additionally, the lengths of the first protrusion (131) and the second protrusion (132) along the front-rear direction may differ from each other. Specifically, the length of the first protrusion (131) along the front-rear direction may be greater than the length of the second protrusion (132) along the front-rear direction. Therefore, the gap between the outer end of the second protrusion (132) and the inner surface of the tube (103) may be greater than the gap between the outer end of the first protrusion (131) and the inner surface of the tube (103) with respect to the front-rear direction, and the passage through which combustion gas flows may be formed in the space between the second protrusion (132) and the inner surface of the tube (103).

[0036] When forming a through hole (12), it can be formed through the following process. At the location where the through hole (12) is to be formed, a cutting process can be performed on the body part (11) by punching or the like along a part of the profile forming the perimeter of the first part and the second part. At this time, the upper (121) and lower parts of the through hole (12) may not be cut. After the cutting is performed, the part corresponding to the first part can be bent along the part that will become the upper (121) of the through hole (12) to form a first protruding piece (131). Additionally, the part corresponding to the second part can be bent along the part that will become the lower (122) of the through hole (12) to form a second protruding piece (132). As the first protruding piece (131) and the second protruding piece (132) are formed by bending, the through hole (12) can be formed between the first protruding piece (131) and the second protruding piece (132). Since the through hole (12) can be formed in this way, the process of producing the baffle plate (1) can be simplified and productivity can be improved.

[0037] Among the multiple protruding pieces (13), the protruding pieces protruding from the same through hole (12) may protrude in the same direction. Among the multiple through holes (12), the directions in which the protruding pieces protrude from adjacent through holes (12) may be opposite to each other. That is, as moving along the vertical direction, if the protruding pieces (13) protrude forward from one through hole (12), the protruding pieces (13) protrude backward from the next through hole (12), and the protruding pieces (13) protrude forward from the subsequent through hole (12). Since the protruding pieces (13) have such directions of protrusion, the first protruding piece (131) and the second protruding piece (132) of adjacent through holes (12) have the effect of forming a single wall, and this wall can have the effect of alternating directions as it moves along the vertical direction. Therefore, when the combustion gas flows from the bottom to the top within the flue (103), it flows through every corner while drawing a zigzag path in the front-rear direction and stays within the flue (103) for a long time, thereby reducing the occurrence of flow stagnation areas and achieving high thermal efficiency.

[0038] The left and right ends of the first protruding piece (131) and the second protruding piece (132) may have a straight shape extending along the front-rear direction as illustrated.

[0039] Among the upper protrusions (133, 134) protruding from the circumference of the through hole (12) located adjacent to the top of the body part (11), the upper protrusion corresponding to the first protrusion (131) may be the first upper protrusion (133), and the upper protrusion corresponding to the second protrusion (132) may be the second upper protrusion (134). The length of the first upper protrusion (133) along the front-rear direction may be greater than the length of the first protrusion (131) along the front-rear direction. On the other hand, the length of the second upper protrusion (134) along the front-rear direction may be smaller than the length of the second protrusion (132) along the front-rear direction. The sum of the areas of the first upper protrusion (133) and the second upper protrusion (134) may also be equal to the area of ​​the through hole (12). As illustrated, two first upper protrusions (133) may be arranged at the uppermost part of the body portion (11), and two second upper protrusions (134) may be arranged at the uppermost part of the body portion (11), but the number is not limited thereto. By forming the size of the upper protrusions (13) differently from the size of the protrusions (13) located in other parts as described above, the combustion gas that has already been sufficiently cooled at the top of the tube (103) can stay for a longer period along a relatively longer path inside the tube (103) than at the bottom of the tube (103), and in some cases, recirculation can occur inside, thereby improving the heat exchange efficiency.

[0041] Variant example

[0042] FIG. 9 is a perspective view showing a baffle plate (1b) according to one variation of one embodiment of the present invention. FIG. 10 is a perspective view showing a baffle plate (1b) according to another variation of one embodiment of the present invention. FIG. 11 is an enlarged view showing a part of the structure of a baffle plate according to one variation of one embodiment of the present invention.

[0043] Referring to the drawings, the baffle plate (1b, 1c) according to variations of one embodiment of the present invention may further include at least one intermediate protrusion (16b, 16c). The intermediate protrusion (16b, 16c) is a component that protrudes from the body portion between a plurality of through holes (12b) and has the same shape as an adjacent protrusion among the plurality of protrusions (13b) and protrudes in the same direction. Accordingly, the first intermediate protrusion (161b, 161c) has the same shape as the adjacent first protrusion (131b) and protrudes from the body portion along the same direction. Additionally, the second intermediate protrusion (162b, 162c) has the same shape as the adjacent second protrusion (132b) and protrudes from the body portion along the same direction. As intermediate protrusions (16b, 16c) are formed, the path through which combustion gas flows can have a larger area adjacent to the inner surface of the tube (103) than when only the first protrusion (131b) and the second protrusion (132b) are located, thereby increasing the heat exchange efficiency.

[0044] In the baffle plate (1b) according to one variation of FIG. 9, intermediate protrusions (16b) are shown formed in the area (A1) adjacent to the bottom (112). Also, in the baffle plate (1c) according to another variation of FIG. 10, intermediate protrusions (16c) are shown formed in the middle area (A2) of the baffle plate (1c) with respect to the vertical direction.

[0045] In addition, according to one variant, a projection (17b) protruding downward or upward from a portion of the upper or lower end of the through hole (12b) may be further formed. Referring to FIG. 11, this projection (17b) may be formed by cutting a portion of the protrusion and passing it through another protrusion. A baffle plate (1b) according to one variant may be formed by further combining a protrusion addition unit (19b) with a baffle plate (1) according to one embodiment. The protrusion addition unit (19b) may have a first protrusion (131b) and a second intermediate protrusion (162b), and may have a slit (182b) in the first protrusion (131b). The first intermediate protrusion (161b) and the second protrusion (132b) may be formed in the body portion. A cut may be made in the shape of the aforementioned projection (17b) at the center of the first intermediate protrusion (161b) formed in the body portion, and by bending it in the vertical direction, an intermediate opening (181b) in the shape of the projection (17b) may be formed on the projection (17b) and the first intermediate protrusion (161b). However, a slit may be formed in the protrusion formed in the body portion, and a projection may be formed on the protrusion portion unit to form a connection.

[0046] By inserting a projection (17b) into the slit (182b), a protruding part addition unit (19b) can be attached to the body part. At this time, since the protruding part addition unit (19b) covers a part of the through hole (12b), the size of the through hole (12b) where the protruding part addition unit (19b) is placed may be smaller than the size of the through hole where it is not placed. As the size of the through hole (12b) is reduced, the flow velocity of the combustion gas passing through the through hole (12b) may be increased. One protruding part addition unit (19b) may be placed in each through hole (12b).

[0047] FIG. 12 is a diagram showing the flow velocity profile of combustion gas occurring within the flue (103) when an exemplary baffle plate (104) is inserted into the flue (103). FIG. 13 is a diagram showing the flow velocity profile of combustion gas occurring within the flue (103) when a baffle plate (1) according to an embodiment of the present invention is inserted into the flue (103). In the diagram, the darker the shading, the faster the flow velocity of the combustion gas.

[0048] Referring to the drawing, it can be seen that the area of ​​the dark shaded region occurring in the area adjacent to the bottom of the exemplary baffle plate (104) is smaller than the area of ​​the dark shaded region occurring in the area adjacent to the bottom of the baffle plate (1) according to one embodiment of the present invention. It can also be confirmed that the dark shaded regions that occur thereafter appear larger in the area adjacent to the baffle plate (1) according to one embodiment of the present invention. Therefore, when using the baffle plate (1) according to one embodiment of the present invention, the flow velocity of the combustion gas increases, and the flow adjacent to the inner surface of the flue (103) increases, thereby reducing the occurrence of a flow stagnation region. As a result, compared to using the exemplary baffle plate (104), when using the baffle plate (1) according to one embodiment of the present invention, the heat exchange efficiency is increased, the temperature of the combustion gas at the outlet of the flue (103) is lowered, and the magnitude of the pressure drop can be reduced.

[0049] In the foregoing, although all components constituting the embodiments of the present invention have been described as being combined or operating together, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all such components may be selectively combined and operated in one or more ways. Furthermore, terms such as "include," "constitute," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the present invention.

[0050] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0051] 1, 1b, 1c: Buffle plate 11 : Body part 12, 12b : Through hole 13, 13b: protruding piece 14 : Protrusion 15 : Incision 16b, 16c: Middle protrusion 17b : protrusion 19b : Protruding piece additional unit 100 : Water heater 101 : Case 102 : Burner 103 : Association 104: Exemplary buffalo plate 105 : Communist China 106: Combustion chamber 111 : Top of the body 112: Bottom of the body 121: Top of the through hole 122 : Bottom of the penetration hole 131, 131b: First protrusion 132, 132b: Second protruding piece 133 : First upper protruding piece 134 : Second upper protruding piece 161b, 161c: First intermediate protrusion 162b, 162c: Second intermediate protrusion 181b : middle opening 182b : slit 1041 : Exemplary body part 1042 : Exemplary penetration hole 1043 : Exemplary protrusion

Claims

Claim 1 A baffle plate inserted into a tube of a water heater for heating water, wherein the direction in which the tube extends is called the vertical direction and a direction perpendicular to the vertical direction is called the front-rear direction, and the plate is formed in a plate shape extending along the vertical direction and perpendicular to the front-rear direction and inserted into the tube; a plurality of through holes penetrating the body and arranged along the vertical direction; A baffle plate comprising a plurality of protruding pieces protruding along the front-rear direction from a portion of the circumference of the plurality of through holes, wherein some of the protruding pieces protruding along the front-rear direction from the upper end of the plurality of through holes are a plurality of first protruding pieces, and other protruding pieces protruding along the front-rear direction from the lower end of the plurality of through holes are a plurality of second protruding pieces, wherein the plurality of first protruding pieces includes a first upper protruding piece located adjacent to the upper end of the body part, and the plurality of second protruding pieces include a second upper protruding piece located adjacent to the upper end of the body part, wherein the length of the first upper protruding piece along the front-rear direction is greater than the length of the remaining first protruding pieces excluding the first upper protruding piece among the plurality of first protruding pieces along the front-rear direction, and the length of the second upper protruding piece along the front-rear direction is smaller than the length of the remaining second protruding pieces excluding the second upper protruding piece among the plurality of second protruding pieces along the front-rear direction. Claim 2 A baffle plate according to claim 1, wherein the first and second protrusions each have a shape corresponding to at least a part of the first part and at least a part of the second part when the shape corresponding to the shape of the through hole is divided into two parts including the first and second parts. Claim 3 In paragraph 2, the first and second protruding pieces each have a shape corresponding to the first and second parts, respectively, a baffle plate. Claim 4 A baffle plate according to claim 1, wherein the outer end of the first protruding piece and the outer end of the second protruding piece are formed in a shape corresponding to each other based on the front-rear direction. Claim 5 A baffle plate according to claim 1, wherein the first protruding piece and the second protruding piece have different shapes from each other. Claim 6 A baffle plate according to claim 1, wherein the outer end of the first protruding piece, based on the front-rear direction, has a shape that protrudes outwardly in a convex manner. Claim 7 A baffle plate according to claim 1, wherein the outer end of the second protruding piece is concavely sunken inward with respect to the front and rear directions. Claim 8 A baffle plate according to claim 1, wherein the lengths of the first and second protruding pieces along the front-rear direction are different from each other. Claim 9 A baffle plate according to claim 8, wherein the length of the first protruding piece along the front-rear direction is greater than the length of the second protruding piece along the front-rear direction. Claim 10 A baffle plate in claim 1, wherein the protruding pieces among the plurality of protruding pieces protruding from the same through hole protrude in the same direction, and the directions in which the protruding pieces protrude from adjacent through holes among the plurality of through holes protrude are opposite to each other. Claim 11 A baffle plate according to claim 1, wherein the direction orthogonal to both the up-down direction and the front-back direction is called the left-right direction, the upper and lower ends of the plurality of through holes extend along the left-right direction, and the plurality of through holes further have left and right ends extended along the up-down direction to have a rectangular perimeter. Claim 12 A baffle plate according to claim 1, further comprising at least one intermediate protruding piece that protrudes from the body portion between the plurality of through holes and has the same shape as an adjacent protruding piece among the plurality of protruding pieces and protrudes in the same direction.

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