JP7785376B2 - Deposit prevention structure for heat exchanger, and heat exchanger having deposit prevention structure - Google Patents

Description

The present invention relates to a deposit-suppressing structure for a heat exchanger and a heat exchanger having a deposit-suppressing structure. In particular, the present invention relates to a structure that suppresses the accumulation of deposits on the surface of heat transfer tubes near the liquid surface in a heat exchanger that is used by immersing it in a liquid tank, and a heat exchanger equipped with said structure.

Immersed-type heat exchangers, made up of corrosion-resistant heat transfer tubes, are used in 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).

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 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, structural steel, 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 through a tank filled with acid solution and cleaned. The acid solution is often heated to approximately 60-110°C, and one or more heat exchangers are installed within 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 on the heat exchanger surface. 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 an 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 oily contaminants (hereinafter referred to as "scale") and prevents deterioration of heat exchange efficiency and deformation.

Furthermore, in immersion-type heat exchangers used in acid baths for pickling, scale buildup 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 buildup 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 areas where the heat transfer tube surface comes into contact with the liquid surface, for example, when a steel plate is immersed in an acid bath, the liquid level fluctuates up and down, causing scale buildup on the heat transfer tube surface. This scale forms when the volatile components of the acid solution that has adhered to the heat transfer tube surface evaporate, leaving behind solid components. The acid solution then repeatedly adheres to these solid components, causing the volatile components to evaporate again, forming large solid masses. This scale hardens and grows into larger masses, which can cause damage to the heat transfer tube and make it difficult to remove.

In response to this problem, Patent Document 2 describes a method for covering heat transfer tubes of heat exchangers used in solutions such as acid solutions used to clean steel plates with fluororesin heat-shrink tubing as a way to prevent scale buildup on the outer surface of heat transfer tubes near the contact point with the liquid surface. Specifically, the method involves positioning the heat-shrink tubing so that it covers the area of the heat transfer tube where scale will buildup, and then heating the heat-shrink tubing in this position to form a protective tube covering the heat transfer tube. This method is said to prevent damage to the heat transfer tube because scale does not buildup directly on the heat transfer tube, but rather on the protective tube.

However, with the technology of Cited Document 2, although scale does not adhere directly to the heat transfer tubes, 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 large clumps of deposits that have integrated 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.

Japanese Patent Application Laid-Open No. 2003-213466 JP 2011-141080 A

The present invention has been made to solve these problems with the prior art, and aims to provide a deposit suppression structure for a heat exchanger and a heat exchanger having such a deposit suppression structure.

As a result of research and development in consideration of the above-mentioned problems, the present invention was arrived at. Specifically, the deposit prevention structure for a heat exchanger according to the present invention is a heat exchanger including 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 including 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 including 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.

Furthermore, the above problem is more preferably solved by providing the tubular member with sealing members at both the first end and the second end.

Furthermore, it is preferable that the tubular member has a contact angle of 90° or more on at least the outer surface.

The cylindrical member preferably has one or more coating layers on its outer surface. The coating layers are preferably at least partially made tearable. The coating layers preferably have a contact angle of 90° or greater on at least the outer surface.

In order to solve the above-mentioned problems, the present invention provides a heat exchanger having a deposit suppression structure, the 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 fitted onto one or more of the heat transfer tubes, the tubular member having a first end and a second end, the tubular member including a seal member on at least one of the first end and the second end, and the tubular member being installed so that one end of the tubular member is positioned above the liquid level in the liquid tank. 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 including 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 including 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.

Furthermore, it is preferable that the heat transfer tube of a heat exchanger having the deposit suppression structure of the present invention has at least the outer surface material made of at least one type of resin selected from fluororesins.

This invention makes it possible to effectively prevent or suppress the formation of deposits on the surface of heat exchanger tubes. This significantly reduces the frequency of maintenance work to remove deposits from heat exchangers, and also makes it easier to remove deposits, minimizing damage to the heat exchanger tubes.

1 is a schematic diagram of a heat exchanger equipped with a deposit suppression structure for a heat exchanger of the present invention. FIG. 1 is a schematic diagram of the structure of a conventional heat exchanger near the liquid surface. A conceptual diagram of deposit formation in a conventional heat exchanger. 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. 1 is a conceptual diagram of deposit formation in a heat exchanger having a deposit suppression structure of the present invention. 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. 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. 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. 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. 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.

The following describes preferred embodiments of the deposit suppression structure for a heat exchanger according to the present invention, and a heat exchanger having the deposit suppression structure, using the drawings. In each drawing, identical elements are designated by the same reference numerals, and where similar explanations are given, duplicate explanations may be omitted.

Figure 1 is a schematic diagram of an example of a heat exchanger having a deposit suppression structure for a heat exchanger of the present invention. As shown in Figure 1, the heat exchanger 100 disposed in the 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 suppression structure of the present invention.

Heat exchanger 100, commonly known as the throw-in type, is used with the heat transfer tubes almost entirely immersed in the liquid in liquid tank A. Heat transfer tube 110 consists of one or more tubes, arranged in a loop shape of a size that is convenient for insertion into liquid tank A. The ends of heat transfer tube 110 are positioned higher than liquid level B. The ends of heat transfer tube 110 positioned above the liquid level are connected to a heat source (e.g., a steam supply port, not shown) pipe, from which a heat transfer medium (or refrigerant) is supplied into the heat transfer tube 110.

A cylindrical member 130, used as the deposit-suppressing structure of the present invention, is positioned near the liquid surface B of the heat transfer tube 110. For example, in the pickling process for steel plates, steel wire rods, etc., the acid liquid level in the liquid tank fluctuates within a certain range due to operations such as immersing the object to be cleaned in the acid tank, adjusting the temperature, and stirring the liquid in the tank. Furthermore, when objects to be cleaned, such as steel plates or steel wire rods, are continuously transported through the acid tank at high speed, droplets are generated on the acid liquid surface. When this occurs, the acid liquid adheres to the surface of the heat transfer tube above the liquid surface, and its volatile components evaporate, resulting in the deposition of solids on the heat transfer tube surface. Repeated cycles of this process result in deposits growing larger. The cylindrical member 130 suppresses the liquid surface oscillation 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 placed at the upper end of the cylindrical member, the effect of suppressing evaporation of volatile components of the acid solution inside the cylindrical member can be expected. In this way, the cylindrical member 130 prevents or suppresses the formation of deposits on the outer surface of the heat transfer tube 110 inside the cylindrical member. Even if deposits do form on the outer surface of the cylindrical member 130, the surface of the cylindrical member 130 has a simple shape, making it very easy to remove the deposits.

Figure 2 is a schematic diagram of the structure near the liquid surface of an example of a conventional heat exchanger, and Figure 3 is a conceptual diagram of deposit formation in a conventional heat exchanger. Figure 4 is a schematic diagram of the structure near the liquid surface of an example of a heat exchanger equipped with the deposit prevention structure of the present invention. Figure 4 shows an example in which a seal member 131 is disposed at the lower end of a cylindrical member 130. Figure 5 is a conceptual diagram of deposit formation in an example of a heat exchanger equipped with the deposit prevention structure of the present invention. In the conventional heat exchanger of Figure 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 Figure 3, 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. 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.

The tubular member is preferably positioned so that its first end is above the liquid surface and its second end is below the liquid surface. Here, "below the liquid surface" refers to a position lower than the range of liquid surface fluctuations, and it is preferable that the second end of the tubular member is always immersed in the liquid in the liquid tank, even when the liquid surface fluctuates. "Above the liquid surface" refers to a position higher than the range of liquid surface 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 surface. In a heat exchanger in which a support plate or top plate is disposed between the liquid surface in the liquid tank and the connection between the heat transfer tube and the heat source piping, it is more preferable that the tubular member be connected to or penetrate the support plate or top plate. A tubular member positioned in this manner can block droplets generated on the liquid surface from the heat transfer tube.

Figure 6 is a structural schematic diagram of the vicinity of the liquid surface of another example of a heat exchanger equipped with the deposit suppression structure of the present invention. The tubular member may be fitted over all of the heat transfer tubes of the heat exchanger as a whole, as in Figure 4, or may be fitted over divided heat transfer tubes as in Figure 6(a), or may be fitted over only a portion of the heat transfer tubes as in Figure 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.

The cross-sectional shape of the tubular 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). It may also 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 tubular member can be determined appropriately depending on the arrangement and maintenance conditions of the heat exchanger. Furthermore, the cross-sectional shapes and cross-sectional areas of the first and second ends do not need to be the same. For example, 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, as shown in FIG. 7(f). 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.

The cylindrical member may have any shape as described above after being placed in the heat exchanger; its 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 that it surrounds the heat transfer tube when attached to the heat exchanger. Alternatively, the cylindrical member may be a plurality of plates bonded together to form a cylindrical shape around the heat transfer tube. While the wall of the cylindrical member is preferably gap-free, it may also be constructed with a mesh or slits, as long as it suppresses the sloshing of the liquid surface inside the cylindrical member and prevents droplets from adhering to the heat transfer tube. In this case, the outer surface of the cylindrical member is preferably one that is resistant to deposits and allows any deposits that do form to be easily removed.

It is preferable that at least the outer surface of the tubular member is 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 applying a coating made of a material with a large contact angle to the outer surface of the tubular member. 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 form 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, it is preferable that the outer surface of the coating layer be smooth and have a contact angle of 90° or more.

The tubular member preferably has a structure including one or more coating layers on its outer surface. When multiple coating layers are provided, the coating layers are preferably structured to be peelable one by one. A structure including a coating layer 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 including multiple coating layers, the outer coating layer can be peeled off one by one along with the deposits, allowing for easy and repeated removal of a new surface. The coating layer of the tubular member may also be structured by wrapping a film-shaped material around the outer surface of the tubular member and fixing it to a cylindrical 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.

The material constituting at least the outer surface of the tubular member is preferably one that is not easily destroyed by the liquid in the liquid tank or the ambient temperature of the tubular member. The material is preferably a metal, resin, or other material that can withstand slight stress or impact. For example, when using a corrosive liquid, the tubular member may be made of a corrosion-resistant metal such as gold, platinum, tantalum, Hastelloy, or nickel alloy, or a resin. Resin materials include polypropylene (PP), glass-reinforced PP, polyvinyl chloride (PVC), fluororesin, and fiber-reinforced plastic (FRP). 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.

The tubular member preferably has a seal member at at least one of the first and second ends. It is more preferable that the seal member be located at the lower end (below the liquid level) of the tubular member, and even more preferable that seal members be located at both the upper and lower ends of the tubular member. The seal member has a structure through which the heat transfer tube is inserted and prevents liquid from passing through the tubular member. It is also more preferable that the seal member has a structure that prevents airflow into the tubular member, and even more preferable that it has a structure that can close the tubular member. Figure 8 is a schematic diagram of an example of a seal plate 800 used as a seal member placed on the tubular member of the deposit-prevention structure for a heat exchanger of the present invention. The seal plate 800 has a through-hole 810 through which the heat transfer tube passes. It is preferable that the material of the seal plate is resistant to destruction by the liquid in the liquid tank and the ambient temperature of the tubular 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 using a corrosive liquid, metals with excellent corrosion resistance such as gold, platinum, tantalum, Hastelloy, and nickel alloys may be used. Alternatively, polypropylene (PP), GF-reinforced PP, polyvinyl chloride (PVC), fiber-reinforced plastic (FRP), the aforementioned fluororesin, fluororubber, perfluoroelastomer, and silicone rubber may be used. The diameter of the through-hole 810 may be 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 may 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. If a structure is desired in which the tubular member is blocked by a sealing member, a filler material such as an O-ring may 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 can be made of a flexible material such as fluororubber, and the diameter of the through hole 810 can be set to the same as or slightly smaller than the outer diameter of the heat transfer tube, thereby blocking the tubular member when the heat transfer tube is inserted. Alternatively, for example, two seal plates can be prepared, and a sheet made of an elastic material such as rubber can be sandwiched and fixed between the seal plates. In this case, the sheet made of elastic material can be provided with holes in positions that fit the through holes of the seal plate, with a diameter that is the same as or slightly smaller than the outer diameter of the heat transfer tube. The two seal plates can also 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, blocking the tubular member.

The sealing member may be prepared by forming it into a shape like the example in 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 sealing member material after arranging the heat transfer tube and tubular member so that it has a shape like the example in Figure 8.

It is more preferable that the tubular member or sealing member has a structure that can be separated. This allows the tubular member to be removed from the heat exchanger without removing heat exchanger parts such as heat transfer tubes and connectors, making it possible to replace just the tubular member.

A cylindrical member equipped with a sealing member can supply gas or liquid through the gap between the sealing member and the heat transfer tube, creating a pressure difference between the inside and outside of the cylindrical member and creating a slight positive pressure inside the cylindrical member. Creating a slight positive pressure can prevent the liquid in the liquid phase from entering the cylindrical member through the gap between the sealing member and the heat transfer tube. The liquid supplied to the cylindrical member can 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.

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).

FIG. 9 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 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 location 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, so that the heat transfer tubes above the liquid surface are shielded from fluctuations in the liquid surface and splashes generated on the liquid surface.

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,
It may be arranged in a U-shape.

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 easily shaped to fit the shape of the liquid tank is preferable. For resin, examples that can be used include polypropylene (PP), GF-reinforced PP, polyvinyl chloride (PVC), fluororesin, and fiber-reinforced plastic (FRP). Among these, resins with excellent chemical resistance, heat resistance, and peelability are preferably made of at least one selected from fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), polychlorotrifluoroethylene (PCTFE), and polyvinylidene fluoride (PVDF). The fluororesin may contain fillers 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.

This invention effectively prevents or inhibits the formation of deposits on the surfaces of heat exchanger heat transfer tubes, significantly reducing the frequency of the arduous maintenance work of removing scale particles that have accumulated on heat transfer tubes, which poses a risk of respiratory harm and contact with acidic solutions. Furthermore, because deposits are easily removed and the work of removing them does not damage the heat transfer tubes, the heat exchanger can be used while maintaining high performance.

A: Liquid tank; B: Liquid surface; C: Area where deposits are formed; 100: Heat exchanger; 110: Heat transfer tube; 120: Connector; 130: Cylindrical member; 131: Seal member; 140: Spacer; 150: Fixing member; 160: Rod seal plate; 800: Through hole; 810: Fixing hole; 820

Claims (8)

In 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 sealing member at at least one of the first end and the second end;

Heat exchanger structure to prevent deposits. 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. 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. 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. 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. 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. In 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. 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.