Deposit prevention structure for heat exchanger, and heat exchanger having deposit prevention structure

Abstract

The purpose of the present invention is to provide a deposit suppression structure for a heat exchanger to be used in a state of being immersed in a liquid, and a heat exchanger having the deposit suppression structure. The present invention addresses the problem by providing: a deposit suppression structure for a heat exchanger that is characterized by comprising a cylindrical member fitted on the outside of, among a plurality of heat transfer pipes, at least one of the heat transfer pipes, and that is characterized in that the cylindrical member has inner and outer surfaces and first and second ends, and the cylindrical member is provided with a seal member at the first end and / or the second end; and a heat exchanger having the deposit suppression structure.

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger structure for suppressing deposits, and a heat exchanger having the structure. In particular, the present invention relates to a structure for suppressing deposits on the surface of heat transfer tubes near the liquid level in a heat exchanger that is used by being immersed in a liquid tank, and a heat exchanger having the structure. [Background technology]

[0002] Immersed-type heat exchangers, which are made up of heat transfer tubes with excellent corrosion resistance, are used as heat exchangers for applications such as chemical cleaning, plating solution temperature control, chemical solution temperature control, and hot spring heat utilization. Immersed-type heat exchangers are made up of one or more heat transfer tubes, and are used by immersing almost the entire heat transfer tube in a liquid tank, with part of the heat transfer tube, i.e., the part that connects to the heat transfer medium or refrigerant piping, outside the liquid (above the liquid surface).

[0003] Chemical cleaning is a method of chemically removing impurities and dirt from the surface of an object using acids, alkalis, solvents, etc. for purposes such as degreasing, derusting, and rust prevention. This method is often performed by immersing the object in a tank containing the chemicals. A heat exchanger is used to heat or cool the chemicals in the tank. Among chemical cleaning methods, pickling is used in fields that handle metal products such as steel plates, wire rods, shaped steel rods, pipes, stainless steel, and titanium plates. It is a cleaning process performed to remove impurities from the surface of metal products, such as oxide films formed during rolling, heat treatment, and welding. Acid solutions such as hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid are used for cleaning. For example, when continuously processing plate materials or wire rods, the plate materials or wire rods are continuously transported and cleaned in a tank filled with acid solution. The acid solution is often heated to approximately 60–110°C, and one or more heat exchangers are installed in the tank. The acid solution in the solution tank contains oxides (scale particles) detached from the steel surface and oily contaminants. When scale particles containing oil adhere to the surface of a heat exchanger, they aggregate and accumulate. The adhesion and accumulation of scale particles on the heat exchanger not only reduces the heat exchange efficiency of the heat exchanger, but also causes the heat exchanger to be crushed by the weight of the scale particles, potentially resulting in damage to the heat exchanger. Furthermore, removing the scale particles from the heat exchanger poses safety issues, as they can come into contact with the acid solution and pose a risk to the respiratory system. To address these issues, Patent Document 1 discloses an invention that sprays compressed air or acid solution in the tank onto the corners of the heat exchanger where scale particles are likely to accumulate and grow, thereby washing away the scale particles and other particles adhering to the corners. This protects the heat exchanger from the aggregation and accumulation of scale particles and oil (hereinafter referred to as "scale") and prevents a decrease in heat exchange efficiency and deformation.

[0004] Furthermore, in a throw-in heat exchanger used in an acid bath for pickling, scale deposition on the heat transfer tube surface near the liquid surface has been a problem. While the technology described in Patent Document 1 is effective in preventing scale deposition on the heat exchanger in the portion completely immersed in the liquid in the bath, it is difficult to achieve this effect near the liquid surface, including the upper portion. In the vicinity of the contact point between the heat transfer tube surface and the liquid surface, for example, when a steel plate is immersed in the acid bath, the liquid level fluctuates up and down, causing scale deposition on the heat transfer tube surface. This scale is formed when the volatile components of the acid deposited on the heat transfer tube surface evaporate, leaving solid components. The acid repeatedly deposits on these solid components, causing the volatile components to evaporate again, forming large solid masses. Such scale hardens and grows into larger masses, which can cause damage to the heat transfer tube and make it difficult to remove.

[0005] In response to this problem, Patent Document 2 describes a method for preventing scale buildup on the outer peripheral surface of a heat transfer tube near the area where the heat transfer tube comes into contact with the liquid surface, in which the heat transfer tube of a heat exchanger used in a solution such as an acid solution used to clean steel plates is covered with a heat-shrinkable tube made of a fluororesin. Specifically, the heat-shrinkable tube is positioned so that the shrunk heat-shrinkable tube covers the area of ​​the heat transfer tube where scale will buildup, and the heat-shrinkable tube is heated in this position to form a protective tube that covers the heat transfer tube. It is said that this method prevents damage to the heat transfer tube because scale does not buildup directly on the heat transfer tube but instead builds up on the protective tube.

[0006] However, with the technology of Patent Document 2, scale does not adhere directly to the heat transfer tubes, but it does adhere to the protective tubes that cover the heat transfer tubes. As a result, if the deposits are not removed frequently, they form large clumps. Furthermore, if the deposits between the heat transfer tubes wrap around the heat transfer tubes and become integrated, removing the deposits becomes even more difficult. The deposits that have formed into large clumps not only reduce the thermal conductivity of the area, but also cause serious problems such as damaging the heat transfer tubes when removing them or causing them to bend. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-213466 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-141080 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve these problems of the conventional technology, and aims to provide a deposit suppression structure for a heat exchanger and a heat exchanger having the deposit suppression structure. [Means for solving the problem]

[0009] As a result of studies in consideration of the above-mentioned problems, the present invention has been arrived at. Specifically, the deposit suppression structure for a heat exchanger according to the present invention is a heat exchanger including one or more heat transfer tubes, the heat exchanger being a heat exchanger in which a liquid comes into contact with the outer surfaces of the heat transfer tubes to perform heat exchange, the heat exchanger including a tubular member inserted around one or more of the heat transfer tubes, and the tubular member teeth The cylindrical member has a first end and a second end, and is provided with a seal member at at least one of the first end and the second end. The tubular member may also have an inner surface and an outer surface.

[0010] Furthermore, the above problem is more preferably solved by providing the cylindrical member with a sealing member at both the first end and the second end.

[0011] It is also preferable that the cylindrical member has a contact angle of 90° or more on at least the outer surface.

[0012] The tubular member has an outer surface on which Layers and above Preferably, the coating layer has a structure comprising the above coating layer. More preferably, the coating layer is a layer having easy tearing properties at least in part. Furthermore, the coating layer preferably has a contact angle of 90° or more on at least the outer surface.

[0013] In order to solve the above-mentioned problems, a heat exchanger having an adhesion suppression structure of the present invention is a heat exchanger including one or more heat transfer tubes, the heat exchanger being disposed in a liquid tank and performing heat exchange by bringing a liquid into contact with the outer surfaces of the heat transfer tubes, the heat exchanger including a tubular member inserted around one or more of the heat transfer tubes, and the tubular member teeth The present invention is characterized in that the tubular member has a first end and a second end, and the tubular member is provided with a seal member on at least one of the first end and the second end, and is installed so that one end of the tubular member is located above the liquid level in the liquid tank. As a result of research in consideration of the above-mentioned problems, the present invention was arrived at. Specifically, the deposit suppression structure for a heat exchanger according to the present invention is a heat exchanger having one or more heat transfer tubes, the heat exchanger performing heat exchange by bringing a liquid into contact with the outer surfaces of the heat transfer tubes, the heat exchanger comprising a tubular member fitted onto one or more of the heat transfer tubes, the tubular member having a first end and a second end, and the tubular member being provided with a seal member on at least one of the first end and the second end. The tubular member may also have an inner surface and an outer surface.

[0014] Furthermore, it is preferable that at least the outer surface of the heat transfer tube of the heat exchanger having the deposit-preventing structure of the present invention is made of at least one type of resin selected from fluororesins. [Effects of the Invention]

[0015] According to the present invention, it is possible to effectively prevent or suppress the formation of deposits on the surfaces of the heat transfer tubes of a heat exchanger. This can significantly reduce the frequency of maintenance work to remove deposits from the heat exchanger, and also makes it easier to remove the deposits, thereby suppressing damage to the heat transfer tubes. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a heat exchanger equipped with a deposit suppression structure for a heat exchanger of the present invention. [Figure 2] FIG. 1 is a schematic diagram of the structure of a conventional heat exchanger near the liquid surface. [Figure 3] A conceptual diagram of deposit formation in a conventional heat exchanger. [Figure 4] 1 is a schematic diagram of the structure near the liquid surface of a heat exchanger having the deposit suppression structure of the present invention. [Figure 5] 1 is a conceptual diagram of deposit formation in a heat exchanger having a deposit suppression structure of the present invention. [Figure 6] 10 is a schematic structural diagram of another example of a heat exchanger having a deposit suppression structure of the present invention, in the vicinity of the liquid surface. [Figure 7] 10A and 10B show examples of the shape of a cylindrical member of the deposit suppression structure of a heat exchanger of the present invention. [Figure 8] 3 is a schematic diagram of an example of a sealing member to be placed on a cylindrical member of the deposit suppression structure of the heat exchanger of the present invention. FIG. [Figure 9] 1 is a schematic diagram of another example of a heat exchanger having a deposit suppression structure for a heat exchanger of the present invention. [Figure 10] 1 is a schematic diagram of another example of a heat exchanger having a deposit suppression structure for a heat exchanger of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention relates to a heat exchanger having a heat exchanger structure for preventing deposits, a heat exchanger having a heat exchanger structure for preventing deposits, and a heat exchanger having the heat exchanger structure.

[0018] Fig. 1 is a schematic diagram of an example of a heat exchanger having a deposit-suppressing structure for a heat exchanger of the present invention. As shown in Fig. 1, a heat exchanger 100 disposed in a liquid tank A includes a heat transfer tube 110, a connector 120 connected to a heat source pipe (not shown), and a cylindrical member 130 that constitutes the deposit-suppressing structure of the present invention.

[0019] The heat exchanger 100, which is generally called the throw-in type, is used with the heat transfer tubes almost entirely immersed in the liquid in the liquid tank A. The heat transfer tube 110 is composed of one or more tubes, and is arranged in a loop shape of a size that is convenient for insertion into the liquid tank A. The end of the heat transfer tube 110 is positioned higher than the liquid level B. The end of the heat transfer tube 110 positioned above the liquid level is connected to a heat source (for example, a steam supply port, not shown) pipe, and a heat medium (or refrigerant) is supplied from there into the heat transfer tube 110.

[0020] A cylindrical member 130, which serves as the deposit-preventing structure of the present invention, is positioned near the liquid surface B of the heat transfer tube 110. For example, during the pickling process for steel plates, steel wires, and other materials, the acid level in the acid bath fluctuates within a certain range due to operations such as immersing the object to be cleaned in the acid bath, adjusting the temperature, and stirring the liquid in the bath. Furthermore, when objects to be cleaned, such as steel plates or steel wires, are continuously transported through the acid bath at high speed, droplets are generated on the acid surface. When this occurs, the acid adheres to the surface of the heat transfer tube above the liquid surface, and its volatiles evaporate, resulting in the deposition of solids on the heat transfer tube surface. Repeated cycles of this process result in the deposition of large deposits. The cylindrical member 130 suppresses the fluctuation of the liquid surface within the cylindrical member and also prevents droplets generated on the liquid surface from adhering to the heat transfer tube. Furthermore, when a sealing member is positioned at the upper end of the cylindrical member, it is expected to be effective in suppressing the evaporation of volatiles from the acid within the cylindrical member. In this way, the tubular member 130 prevents or suppresses the formation of deposits on the outer surface of the heat transfer tube 110 inside the tubular member, and even if deposits form on the outer surface of the tubular member 130, the surface of the tubular member 130 has a simple shape, making it very easy to remove the deposits.

[0021] FIG. 2 is a structural schematic diagram of an example of a conventional heat exchanger near the liquid surface, and FIG. 3 is a conceptual diagram of deposit formation in the conventional heat exchanger. FIG. 4 is a structural schematic diagram of an example of a heat exchanger equipped with a deposit-suppressing structure of the present invention near the liquid surface. FIG. 4 shows an example in which a sealing member 131 is disposed at the lower end of a cylindrical member 130. FIG. 5 is a conceptual diagram of deposit formation in an example of a heat exchanger equipped with a deposit-suppressing structure of the present invention. In the conventional heat exchanger of FIG. 2, the heat transfer tubes 110 are exposed to the liquid with their outer surfaces exposed to the liquid or with the surfaces of the heat transfer tubes 110 individually coated. As shown in FIG. 3, the region C1 where deposits form near the liquid surface of the heat exchanger is located on the outer surfaces of each of the heat transfer tubes 110, and the work of removing the formed deposits must be performed on each heat transfer tube individually. Furthermore, if deposits on the surfaces of the heat transfer tubes 110 are not frequently removed, the deposits on the surfaces of the heat transfer tubes 110 will coalesce and form clumps that wrap around the heat transfer tubes, making them difficult to remove, and other problems have been encountered. In contrast, in the example of a heat exchanger equipped with the deposit suppression structure of the present invention shown in Figure 4, a cylindrical member 130 is arranged to surround the bundle of heat transfer tubes 110. As shown in Figure 5, region C2 where deposits form near the liquid surface is located on the outer surface of the cylindrical member 130, so that even if deposits form, they can be easily removed and there is no risk of damaging the heat transfer tubes during the process of removing the deposits.

[0022] The tubular member is preferably positioned such that its first end is above the liquid level and its second end is below the liquid level. Here, "below the liquid level" refers to a position lower than the range of liquid level fluctuations, and the second end of the tubular member is preferably always immersed in the liquid in the liquid tank, even when the liquid level fluctuates. "Above the liquid level" refers to a position higher than the range of liquid level fluctuations, preferably a position that can cover the heat transfer tube to a position that is out of reach of droplets generated on the liquid level. In a heat exchanger in which a support plate or top plate is disposed between the liquid level in the liquid tank and the connection between the heat transfer tube and the heat source piping, the tubular member is preferably connected to the support plate or top plate or fixed by penetrating them. A tubular member positioned in this manner can block droplets generated on the liquid level from the heat transfer tube.

[0023] Fig. 6 is a structural schematic diagram of another example of a heat exchanger equipped with the deposit suppression structure of the present invention, near the liquid surface. The tubular member may be one that is fitted over all of the heat transfer tubes of the heat exchanger as a whole, as shown in Fig. 4, or one that is fitted over divided heat transfer tubes as shown in Fig. 6(a), or one that is fitted over some of the heat transfer tubes as shown in Fig. 6(b). The arrangement of the tubular member can be determined appropriately depending on the arrangement of the heat exchanger, the occurrence of splashes on the liquid surface, maintenance conditions, etc.

[0024] The cross-sectional shape of the cylindrical member 130 is not limited as long as it has an inner surface, an outer surface, and a first end and a second end. For example, the cross-sectional shape is not limited to a circular shape as shown in FIG. 7(a), but may be a square shape as shown in FIG. 7(b) or a polygonal shape as shown in FIG. 7(c) (the example in FIG. 7(c) is a hexagon). The cross-sectional shape may also be irregular, as shown in FIG. 7(d) or (e), to match the arrangement of the heat transfer tubes. The shape of the cylindrical member can be determined appropriately depending on the arrangement and maintenance conditions of the heat exchanger. The cross-sectional shapes and cross-sectional areas of the first and second ends do not need to be the same. For example, as shown in FIG. 7(f), the cross-sectional area of ​​the first end above the liquid surface may be larger and the cross-sectional area of ​​the second end below the liquid surface may be smaller. In the case of a shape such as that shown in Figure 7(f), the wall of the cylindrical member is inclined, which has the advantage that droplets adhering to the surface of the cylindrical member tend to fall off easily, and even if deposits grow, the grown deposits tend to fall off under their own weight.

[0025] The cylindrical member may have any shape as described above after being placed in the heat exchanger; the shape before being placed in the heat exchanger is not limited. For example, the cylindrical member may be a single plate material rolled into a cylindrical shape and fixed so as to surround the heat transfer tube when attached to the heat exchanger. Alternatively, the cylindrical member may be a plurality of plate materials bonded together to form a cylindrical shape around the heat transfer tube. The wall of the cylindrical member is preferably gap-free, but may also be formed into a mesh or slits, as long as it is effective in suppressing the swaying of the liquid surface inside the cylindrical member and preventing droplets from adhering to the heat transfer tube. In this case, the outer surface of the cylindrical member is preferably a surface that is resistant to deposits and from which any deposits that do form can be easily removed.

[0026] At least the outer surface of the tubular member is preferably smooth and has a contact angle of 90° or more. For example, the condition of the outer surface can be adjusted by polishing the outer surface of the tubular member to adjust the surface shape, or by providing the outer surface of the tubular member with a coating made of a material with a large contact angle. By making the outer surface of the tubular member have a contact angle of 90° or more, the tubular member is less likely to develop deposits on its outer surface, and any deposits that do develop can be easily removed. In the case of a structure in which a coating layer is provided on the outer surface of the tubular member, as described below, the outer surface of the coating layer is preferably smooth and has a contact angle of 90° or more.

[0027] The tubular member has a 1 on its outer surface. Layers and above It is preferable that the coating layer is a structure having the coating layer. layerWhen provided with a coating layer, it is preferable that the coating layer has a structure that allows it to be peeled off layer by layer. A structure in which a coating layer is provided on the surface of a tubular member can be highly effective again by peeling off the coating layer to create a new surface when the surface of the tubular member becomes dirty or when repeated removal of deposits from the surface of the tubular member makes it difficult to remove the deposits. Furthermore, in a structure in which multiple coating layers are provided, the outermost coating layer can be peeled off layer by layer, along with the deposits, allowing for easy and repeated removal of a new surface. Furthermore, the coating layer of the tubular member may have a structure in which a film-shaped material is wrapped around the outer surface of the tubular member and fixed to the tubular shape. In this case, the film can be peeled off and removed by undoing the cylindrical fixation of the coating layer. Furthermore, at least a portion of the coating layer may be made easily tearable. The coating layer can be made easy to tear by methods such as making cuts or scratches on the surface of the coating layer to make it easier to tear along the cuts, thinning the thickness of part of the coating layer to make it easier to tear, or using a tube or film with easy tearing properties made from a material that is a mixture of multiple resins as the coating layer. When a coating layer with easy tearing properties is used, no special tools are required to peel off the coating layer, making it easier to work with.

[0028] The material constituting at least the outer surface of the cylindrical member is preferably one that is not easily destroyed by the liquid in the liquid tank or the ambient temperature of the cylindrical member. The material is preferably a metal, resin, or other material that will not be destroyed even when subjected to slight stress or impact. For example, when using a corrosive liquid, the cylindrical member may be made of a metal with excellent corrosion resistance, such as gold, platinum, tantalum, Hastelloy, or a nickel alloy, or a resin. For resin, for example, polypropylene (PP), glass fiber-reinforced PP, polyvinyl chloride (PVC), fluororesin, or fiber-reinforced plastic (FRP) can be used. Among these, fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), polychlorotrifluoroethylene (PCTFE), and polyvinylidene fluoride (PVDF) have a wide range of applications due to their excellent chemical resistance, heat resistance, and peelability.

[0029] The cylindrical member preferably has a seal member at at least one of the first end and the second end. It is more preferable that the seal member be disposed at the lower end (below the liquid surface) of the cylindrical member, and even more preferable that seal members be disposed at both the upper and lower ends of the cylindrical member. The seal member has a structure through which the heat transfer tube is inserted and which prevents liquid from passing through the cylindrical member. Furthermore, the seal member preferably has a structure which prevents air from passing through the cylindrical member, and even more preferably has a structure which can close the cylindrical member. FIG. 8 is a schematic diagram of an example of a seal plate 800 used as a seal member disposed in the cylindrical member of the deposit-preventing structure for a heat exchanger of the present invention. The seal plate 800 has a through-hole 810 through which the heat transfer tube is inserted. The seal plate is preferably made of a material that is not easily damaged by the liquid in the liquid tank and the ambient temperature of the cylindrical member. The material may be metal, resin, or any other material that can withstand slight stress and impact, and is not particularly limited. For example, when a corrosive liquid is used, metals with excellent corrosion resistance, such as gold, platinum, tantalum, Hastelloy, and nickel alloys, can be used. Alternatively, polypropylene (PP), glass fiber reinforced PP, polyvinyl chloride (PVC), fiber-reinforced plastic (FRP), the aforementioned fluororesin, fluororubber, perfluoroelastomer, and silicone rubber can be used. The diameter of the through-hole 810 is preferably set to be the same as or slightly larger than the outer diameter of the heat transfer tube, taking into account the outer diameter of the heat transfer tube. A filler material can be placed in the through-hole 810 of the seal plate 800 to reduce the gap between the through-hole 810 and the heat transfer tube. To achieve a structure in which the cylindrical member is closed by a sealing member, a filler material, such as an O-ring, can be placed in the through-hole 810 of the seal plate 800 to fill the gap between the through-hole 810 and the heat transfer tube. Alternatively, the seal plate may be made of a flexible material such as fluororubber, and the diameter of through hole 810 may be the same as or slightly smaller than the outer diameter of the heat transfer tube, thereby enabling the cylindrical member to be closed when the heat transfer tube is inserted. Alternatively, for example, two seal plates may be prepared, and a sheet made of an elastic material such as rubber may be sandwiched and fixed between the seal plates.In this case, it is advisable to provide a hole in the sheet made of elastic material at a position that fits the through-hole in the seal plate, with the diameter being the same as or slightly smaller than the outer diameter of the heat transfer tube. The two seal plates can also be configured to be fixed using fixing holes 820. The sheet made of elastic material placed between the two seal plates fills the gap between the through-hole 810 and the heat transfer tube, closing off the tubular member.

[0030] The sealing member may be prepared by forming it into a shape as shown in the example of Figure 8 before inserting the heat transfer tube, and then inserting the heat transfer tube into the through hole 810 and fixing it to the tubular member, or it may be formed by filling the space between the tubular member and the heat transfer tube with the material of the sealing member so that the shape as shown in the example of Figure 8 is obtained after arranging the heat transfer tube and the tubular member.

[0031] It is more preferable that the cylindrical member or the sealing member has a structure that can be separated, which allows the cylindrical member to be removed from the heat exchanger without removing heat exchanger parts such as the heat transfer tube and connector, and allows replacement of the cylindrical member alone.

[0032] A cylindrical member equipped with a sealing member can supply gas or liquid through a gap between the sealing member and the heat transfer tube, creating a pressure difference between the inside and outside of the cylindrical member, thereby creating a slight positive pressure inside the cylindrical member. Creating a slight positive pressure can prevent the liquid in the liquid phase from penetrating into the cylindrical member through the gap between the sealing member and the heat transfer tube. The liquid supplied to the cylindrical member may be water, but it is more preferable for concentration control that the liquid be the same type as the liquid in the liquid phase. Furthermore, if the liquid supplied to the cylindrical member is an acid solution, a self-cleaning effect against scale buildup can be expected.

[0033] In addition to the connector 120 that connects the heat transfer tube 110 to the heat source piping and the cylindrical member 130, the heat exchanger 100 may also include a spacer 140 that maintains the position of the heat transfer tube 110 in the liquid tank A, a fixing member 150 that connects the spacers together to maintain their shape, and a rod 160 that prevents the heat transfer tube 110 from floating up (see Figure 1).

[0034] FIG. 9 is a schematic diagram of another example of a heat exchanger provided with a deposit suppression structure for a heat exchanger of the present invention. A plurality of heat transfer tubes 110 fixed in a loop shape are arranged in parallel, and the end of each heat transfer tube 110 is connected to a connector (not shown) that connects to the heat source piping. Near the joints of the heat transfer tubes, the heat transfer tubes are gathered in one place on both the inlet and outlet sides of the heat medium, and a cylindrical member 130 is arranged to cover the portion of the gathered heat transfer tubes 110 that is near the liquid surface. The upper end of the cylindrical member (above the liquid surface) is connected to a top plate 160 that functions as a lid for the liquid tank, and the heat transfer tubes above the liquid surface are structured to be insulated from the fluctuation of the liquid surface and splashes generated on the liquid surface.

[0035] 10 is a schematic diagram of another example of a heat exchanger equipped with a deposit suppression structure for a heat exchanger of the present invention. A plurality of heat transfer tubes 110 are bundled and arranged in a U-shape, and the ends of the heat transfer tubes 110 are connected to a connector 120 that leads to a heat source pipe. The bundle of heat transfer tubes is arranged so that the inlet end and outlet end of the heat medium are adjacent to each other, and the portions of the heat transfer tubes 110 near the liquid surface are collectively inserted into a cylindrical member 130. The heat exchanger may be one in which the heat transfer tubes 110 are arranged in a loop shape, or, as in the example of FIG. 10, They may be arranged in a U-shape.

[0036] In the heat exchanger having the deposit suppression structure of the present invention, the heat transfer tube preferably has at least one outer surface made of a material selected from fluororesins. Any material is sufficient as long as it is not easily damaged by the liquid in the liquid tank or the ambient temperature of the tubular member. While the material may be metal, a resin that can be freely shaped to fit the shape of the liquid tank is preferable. For resin, examples that can be used include polypropylene (PP), glass fiber reinforced PP, polyvinyl chloride (PVC), fluororesin, and fiber-reinforced plastic (FRP). Among these, at least one fluororesin selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), polychlorotrifluoroethylene (PCTFE), and polyvinylidene fluoride (PVDF) is more preferable, as these resins have excellent chemical resistance, heat resistance, and peelability. The fluororesin may contain a filler to impart or improve thermal conductivity, electrical conductivity, barrier properties, or mechanical strength. Examples of the filler contained in the fluororesin include amorphous carbon particles, graphite particles, and glass fibers. [Industrial Applicability]

[0037] According to the present invention, it is possible to effectively prevent or suppress the formation of deposits on the surfaces of the heat transfer tubes of a heat exchanger, and to significantly reduce the frequency of the harsh maintenance work of removing scale particles that have adhered to and accumulated on the heat transfer tubes, which poses the risk of respiratory harm and contact with acidic solutions. In addition, because the deposits are easily removed and the work of removing the deposits does not damage the heat transfer tubes, the heat exchanger can be used while maintaining high performance. [Explanation of symbols]

[0038] A: Liquid tank, B: Liquid surface, C: Area where deposits form 100 heat exchanger, 110 heat transfer tube, 120 connector, 130 tubular member, 131 seal member, 140 spacer, 150 fixing member, 160 rod Seal plate 800, through hole 810, fixing hole 820

Claims

1. A heat exchanger having a plurality of heat transfer tubes, The heat exchanger is a heat exchanger in which a liquid comes into contact with an outer surface of the heat transfer tube to exchange heat, the heat exchanger includes a cylindrical member that is fitted onto the heat transfer tubes; the tubular member has a first end and a second end; the tubular member is provided with a seal member at at least one of the first end and the second end; Heat exchanger structure to prevent deposits.

2. the tubular member includes a sealing member at both the first end and the second end; The deposit suppression structure for a heat exchanger according to claim 1.

3. The cylindrical member has a contact angle of 90° or more on at least the outer surface.

3. The deposit suppression structure for a heat exchanger according to claim 1 or 2.

4. The tubular member has one or more coating layers on an exterior surface thereof.

3. The deposit suppression structure for a heat exchanger according to claim 1 or 2.

5. The coating layer of the tubular member is a layer having easy-tear properties imparted to at least a portion thereof. The deposit suppression structure for a heat exchanger according to claim 4.

6. The coating layer of the cylindrical member has a contact angle of 90° or more at least on the outer surface. The deposit suppression structure for a heat exchanger according to claim 4.

7. A heat exchanger having a plurality of heat transfer tubes, The heat exchanger is a heat exchanger that is placed in a liquid tank and performs heat exchange by bringing liquid into contact with the outer surfaces of the heat transfer tubes, the heat exchanger includes a cylindrical member that is fitted onto the heat transfer tubes; the tubular member has a first end and a second end; the cylindrical member includes a seal member at at least one of the first end and the second end; The cylindrical member is installed so that one end thereof is located above the liquid surface of the liquid tank. A heat exchanger with a structure that suppresses deposits.

8. 8. The heat exchanger according to claim 7, wherein at least the outer surface of the heat transfer tube is made of at least one type of resin selected from fluororesins.

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