JP3706254B2 - Heat exchange apparatus equipped with fluororesin heat exchange pipe and surface treatment apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress cutting or damage such as breakage or the like of a heat exchanging pipe near a header pipe mounting position by penetrating a bar-like element passing through the exchanging pipe also via the header pipe, and fixing an opposite side face to the heat exchanging pipe mounting side to the header pipe. SOLUTION: An opening 18 is perforated at a lower surface side of a header pipe 12, and a heat exchanging pipe mounting fixture 21 is mounted in the opening 18. A box nut 22 in which a heat exchanging pipe 15 made of a fluororesin is inserted into its center is threaded with an opposite side of the fixture 21 to the pipe 12 to mount the pipe 15 at the pipe 12. Further, a bar-like element 23 is penetrated along the pipe 15, passed through the nut 22 and the fixture 21, and then penetrated to the pipe 12. A box nut 25 in which the element 23 is inserted at its center is threaded with a bar-like element locking implement 24 mounted at an upper surface side of the pipe 12, and the element 23 is effectively fixed to the pipe 12.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a heat exchange pipe made of fluororesin, passes a heat exchange medium through the pipe, and heats a liquid existing outside the pipe, etc., and a surface treatment apparatus equipped with the heat exchange apparatus About. More specifically, heat that can be suitably used for heating a liquid to be heated such as a surface treatment liquid existing outside by passing water vapor as a heating medium through a heat exchange pipe made of a fluororesin, to a temperature of less than 100 ° C. The present invention relates to an exchange device and a surface treatment device using a heat treatment liquid equipped with the exchange device.
[0002]
[Prior art]
A heat exchange device equipped with a heat exchange pipe made of fluororesin has been known for a long time, and it has already been used for a long time to pass a heated steam through the heat exchange pipe to heat the liquid existing outside the pipe. It is for practical use. The fluororesin is expensive and not particularly excellent in thermal conductivity, but it has corrosion resistance, so it is suitable for heating corrosive surface treatment solutions such as metal pickling or phosphoric acid treatment. Has been used.
[0003]
In such a case, the fluororesin alone may be used for the heat exchange pipe, or there may be a type in which the metal pipe is arranged in close contact with the inside and the fluororesin is used as a coating material. To do. As described above, the use of such a fluororesin focuses on the corrosion resistance of the fluororesin in any case. As a form of utilization at that time, the case where water vapor is allowed to flow inside due to low thermal conductivity, liquid is present outside and heating to a temperature of less than 100 ° C. is the most common.
[0004]
The heat exchange device having such a fluororesin pipe is used for corrosion resistance despite its low thermal conductivity. However, even if this resin is used, fine cracks are generated. The present inventor has found that the cause is the generation of static electricity, and in order to avoid this, heat exchange of the structure shown in FIG. 7 in which a lead wire made of stainless steel is disposed in the pipe The device has already been developed and patented (Japanese Patent Publication No. 61-53640).
[0005]
[Problems to be solved by the invention]
The present inventor has thus contributed to the popularization and technical development of heat exchange devices equipped with fluororesin pipes. In such a situation, the fluororesin heat exchange pipes are attached to the header pipe mounting portion (see FIG. 7 (see part (A)), the pipes were sometimes cut or damaged, and the defective pipes that were damaged each time were replaced with new pipes. This has been difficult for such measures, but so far no complete solution has been found.
[0006]
However, the diameter of the stainless steel wire of the grounding conductor disclosed in the prior art is slightly larger than that specifically described therein, and the end portion is not left in a freely movable state. A structure fixed to a header tube was prepared, and this was used for a long period of time to test the phosphating solution. As a result, despite the fact that a large number of fluororesin heat exchange pipes are installed, an unexpected result is obtained that damage such as cutting or breakage does not occur at all in the header pipe mounting portion of the pipe as before.
[0007]
As described above, the present invention has been developed on the basis of such novel findings, and is an invention that can exhibit excellent effects. Accordingly, it is an object of the present invention to provide a heat exchange device that suppresses the occurrence of damage such as cutting or breakage at the header tube mounting position of the fluororesin heat exchange pipe, and a surface treatment device equipped with the heat exchange device. And an object of the present invention is to provide such a heat exchange device and a surface treatment device.
[0008]
[Means for Solving the Problems]
In the present invention, the heat exchange device employed to achieve the above object has two parallel header pipes having a large number of heat exchange pipe attachment holes along the major axis, and both end parts are attached to the attachment holes of the header pipe. The heat exchange pipe made of fluororesin and the inside of the pipe are penetrated along the long axis of the pipe, and both ends are penetrated in the direction orthogonal to the header pipe, and then fixed to the header pipe on the side opposite to the mounting hole. It comprises a rod-like body or a linear body (referred to as a rod-like body throughout this specification). Moreover, the surface treatment apparatus for that purpose consists of this heat exchange device suspended in the surface treatment tank, and both of the above are solution means adopted to achieve the above object in the present invention.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described based on the heat exchange device and the surface treatment device described in the drawings, but the present invention is not limited to this specific example, and is understood based on the description of the scope of claims. It goes without saying that it is a thing.
First, the overall contents of the present invention will be described based on the surface treatment apparatus described in FIGS.
[0010]
1 and 2, the surface treatment apparatus 1 of the present invention described in FIGS. 1 and 2 has a heat treatment pipe comprising a heat treatment pipe made of a fluororesin in a surface treatment tank 2 having a rectangular horizontal cross section at the top and a tapered shape at the bottom. The apparatus 11 is equipped. The heat exchange device 11 is disposed on both sides of the surface treatment tank 2 and is suspended from the tank wall so that the heat exchange pipe 15 hangs down in the tank 2 with both ends of the header pipe 12 hung on the top of the tank wall. It is equipped in the surface treatment tank 2 in the state of being treated.
Since it arrange | positions in this way, the wide space which can immerse a surface treatment target object exists in the center part of a surface treatment tank. When the heat exchange device 11 is installed in the surface treatment tank 2, the header pipe 12a on the steam supply side of the header pipe 12 is arranged on the center side of the treatment tank 2, and the header pipe 12b on the discharge side is arranged outside. preferable. The reason is that since the treatment liquid to be heated exists inside, the heating efficiency is improved. Both header pipes 12 are connected to the steam supply pipe 13 and the discharger 14 by flanges 16 and bolts 17. Furthermore, a discharge port 3 for discharging the deteriorated used processing liquid is provided at the bottom.
[0012]
The detailed structure of the heat exchange device 11 will be described below with reference to FIG. The header pipe 12 is provided with an opening 18 on the lower surface side, and the heat exchange pipe fitting 21 is attached thereto. The fixture 21 has a through-opening through which a heat exchange pipe is inserted at the center, and a hexagonal or other square-shaped fastener mounting portion on the outer peripheral side so that a fastener such as a wrench can be mounted at the center. There is 21a. Male screws are formed on both sides of the attachment portion 21a, and the attachment tool 21 is screwed into the opening 18 of the header pipe 12 and firmly attached thereto.
[0013]
Next, the cap nut 22 inserted through the heat exchange pipe 15 as the center is screwed into the male screw formed on the outer periphery of the heat exchange pipe fixture 21 on the opposite side to the header pipe 12 and screwed into the header pipe 12. Install. In this case, various conventional means can be employed to prevent leakage of a heat medium such as steam or detachment of the heat exchange pipe. For example, a metal locking ring 27 or a rubber O-ring as shown in FIG. 5 can be used. Further, in order to stably attach the heat exchange pipe, it is preferable to insert a metal tube spacer 26 into the pipe, which can be exemplified by the structure shown in FIG. 6 and is called an insert.
[0014]
The case where the heat exchange pipe is attached to the header pipe using a metal locking ring will be described in more detail with reference to FIG. The heat exchange pipe fitting 21, the cap nut 22, and the two combination locking rings 27 called the front ferrule 27a and the back ferrule 27b are used in combination in a positional relationship as shown in FIG. To attach them, the fitting 21 is first screwed onto the header pipe, and then the heat exchange pipe is passed through the opening in the center of the cap nut 22 and the locking rings 27a, b, and then the cap nut 22 is attached. This is done by screwing on the fixture 21. By doing so, the heat exchange pipe is firmly fixed.
[0015]
The novel mounting structure of the rod-shaped body 23 particularly adopted in the present invention will be described below. The rod-shaped body 23 passes through the pipe from one end to the other end along the heat exchange pipe 15, and subsequently the center of the cap nut 22. The through-hole formed at the center and the through-opening at the center of the heat exchange pipe fitting 21 are penetrated, and the header pipe is further penetrated from one surface to the other surface. After passing through the header pipe 12, the heat medium such as steam is not leaked on the side opposite to the heat exchange pipe fitting 21, and is firmly attached to the header pipe 12 so as not to be detached.
[0016]
The mounting structure is the same as the structure when the heat exchange pipe 15 is attached to the header pipe. Specifically, an opening is provided on the upper surface side of the header pipe, and a rod-like body locking tool 24 is provided there. Installed. The locking tool 24 has a through-hole through which a rod-like body is inserted at the center, and a fastening tool mounting portion having a square structure such as a hexagon so that a fastening tool such as a wrench can be attached to the center of the outer periphery. There is 24a. Male screws are cut on both sides of the mounting portion 24a, and the locking tool 24 is screwed into the opening of the header tube 12 by this male screw and is firmly attached.
[0017]
A male screw is also cut on the outer periphery of the locking member 24 and on the opposite side of the header tube, and a cap nut 25 with a rod-like body 23 inserted through the center is screwed into the male screw and screwed to attach the rod-like body 23 to the header tube. Secure to 12 In this case, various conventional means can be adopted to prevent leakage of heat medium such as steam or detachment of the rod-like body, as in the case of heat exchange pipe installation. The specifically described means can be similarly adopted.
[0018]
The present invention adopts such a structure in order to attach the heat exchange pipe to the header pipe, that is, the part immediately below the cap nut (part A in FIG. 4) of the heat exchange pipe that could not be avoided conventionally. The present invention has an excellent effect that it is possible to avoid the occurrence of damage such as cutting or breakage that has conventionally occurred at the boundary with the cap nut to be inserted or slightly below it.
[0019]
About the utilization form and use range of the heat exchange device of the present invention, although the material of the heat exchange pipe adopted by it is a fluororesin, it has the characteristic of corrosion resistance, but has lower heat resistance and heat transfer than metal. And since it is expensive, it is naturally limited to a range where its characteristics can be utilized. As a result, in order to utilize the characteristics, it is often used for heating, and therefore, it is usually used for heating at 100 ° C. At that time, the pressure and temperature of the steam supplied into the heat exchange pipe are preferably in the range of 1 to 7 kg / cm ² G and 120 to 170 ° C. As described above, the heat medium may be hot water at around 95 ° C. or an oily liquid heat medium. Further, this can be used for cooling, and the present invention does not exclude it.
[0020]
In the present invention, the heat exchange pipe made of fluororesin is used because the fluororesin has characteristics such as heat resistance, chemical resistance and solid non-adhesiveness. As long as it has characteristics, it can be used without any limitation. Specifically, the fluororesin is obtained by fluorinating and polymerizing part or all of the hydrogen of ethylene, and is not limited as long as it has the above characteristics. Either may be sufficient.
[0021]
Specific examples of such a fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetra Fluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE), tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), poly Examples thereof include vinylidene fluoride (PVDF) and polyvinyl fluoride (PVF).
[0022]
Among them, as the fluororesin which can be preferably used in the present invention, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) )
[0023]
Since the heat conductivity of the fluororesin, which is the material of this heat exchange pipe, is lower than that of a metal with a good thermal conductor, its diameter cannot be increased too much, and is preferably about 1.5 to 25 mm, preferably 4 to 15 mm. Good. If it is thicker than 20 mm, the heat conductivity is too low, so it should be avoided. On the other hand, if the thickness is less than 1.5 mm, it becomes too thin, it becomes difficult to insert the rod-shaped body, and the heat medium is also difficult to circulate.
[0024]
The shape of the heat exchange pipe is preferably the shape of a track of an athletic stadium track as shown in FIGS. 1 and 2, but it is a U-shape that is not wound. There may be two or more turns, and there is no particular limitation. In short, it may be a shape that does not impair the purpose of use of the various devices in which it is installed.
[0025]
In the present invention, the rod-like body arranged in the heat exchange pipe is cut or damaged in the heat exchange pipe that has been generated in the vicinity of the engagement portion between the heat exchange pipe and the header pipe by fixing the end of the rod-like body to the header pipe. The rod-shaped body is attached to the header tube so that it can be stably maintained over a long period of time, and the space between the heat-exchange pipe and the rod-shaped body is appropriate. It is preferable that a heat medium such as steam can pass at a high speed.
[0026]
The material is not particularly limited, and heat-resistant engineering plastics can be used, but it is necessary to be exposed to a high-temperature heat medium and processed into a loop or the like simultaneously with the fluororesin. For this reason, metal is naturally preferably employed. Also, when adopting metal, it should be resistant to heat medium such as steam, and it is preferable to avoid the occurrence of fine cracks due to static electricity as mentioned above, so it has excellent electrical conductivity. It is recommended to select a material that can ground static electricity. When a material having poor electrical conductivity is adopted for the rod-shaped body, it is preferable to place a grounding conductor around the rod-shaped body or to wind it in a coil shape.
[0027]
Specifically, such a metal material is preferably stainless steel, titanium, or hastelloy. Since the metal has a smaller coefficient of thermal expansion than fluororesin, which is about 1/10 of that, even this difference will adversely affect the mounting and fixing of heat exchange pipes and rods. It is also necessary to take care not to. Since the rod-shaped body is intended to be used as described above, it is preferable to consider the thickness of the rod-shaped body.
[0028]
As for its thickness, it can be used from a thin line that is unsuitable to be called a rod to a thick rod, but the gap between the rod and the heat exchange pipe can be used to accurately achieve the above intention. It is also necessary to consider this, and it varies in relation to the inner diameter of the heat exchange pipe located outside the rod-shaped body, so the outer diameter of the rod-shaped body is the 10 to 80% of the inner diameter is good, preferably 20 to 60%.
[0029]
Further, the shape is preferably circular in view of the mounting property to a header tube or the like, or the avoidance of damage when coming into contact with the facing fluororesin, but it is polygonal such as square, hexagonal, octagonal, etc. It may be an irregular cross section such as a round shape or an ellipse. Moreover, since it becomes difficult to process into the same shape as this pipe in a fluororesin pipe as it gets thicker, it may be a pipe with a hollow center, and this is desirable when it gets thicker.
[0030]
【Example】
(Example)
4 are suspended in the surface treatment tank 2 as shown in FIGS. 1 to 3, and a zinc phosphate solution (22%) is supplied into the treatment tank 2 to adjust the temperature. The steel material was continuously surface treated at 80 ° C. The heat exchange pipe used at that time is made of polytetrafluoroethylene (PTFE) and has an inner diameter of 12 mm, and the rod-shaped body is made of stainless steel and has an outer diameter of 3 mm. The heating steam supplied to the heat exchange device had a pressure of 5 kg / cm ² G and a temperature of 158 ° C.
[0031]
And after the start of use in February, the total heat exchange pipe was observed in detail, but no damage or breakage of the heat exchange pipe near the header pipe mounting position could be found. No serious damage occurred. Further use was continued and the same observation was made after 6 months, but there was no damage at this time. As a result, according to this embodiment, it has been confirmed that even when a heat exchange apparatus having a large number of heat exchange pipes is used for a long period of time, there is no damage as in the past. Moreover, almost no deposits were formed on the surface.
Further, when a rod-shaped body having a diameter of 7 mm was used, no damage was similarly generated, and no deposit was formed.
[0032]
(Comparative example)
The heat exchange device used in this comparative example is different from that of the embodiment in the thickness, attachment and fixation of the stainless steel wire penetrating through the heat exchange pipe. That is, the stainless steel wire penetrating through the heat exchange pipe does not penetrate the header pipe to the opposite side as in the case of the present invention shown in FIG. 4, and its end is the same as in the case of the prior art shown in FIG. Similarly, it was placed in the header tube without fixing anything. As a result, the end portion is free without any restriction. As for the thickness of the stainless steel wire, one having a diameter of 1 mm, which is similar to that of the prior art, was used.
[0033]
For other points, the surface treatment was started in the same manner as in the example. As a result, steam leakage occurred from the heat exchange pipe 20 days after the start of use, and when the heat exchange pipe was observed, it was confirmed that the heat exchange pipe was damaged near the header pipe mounting position. When the pipe was replaced with a new pipe and the process was continued, 10 days later, similar damage occurred at the same position of the other pipe. After 2 months, a deposit having a thickness of 2 mm was formed.
From the above, regarding the rod (wire) -like body that penetrates the heat exchange pipe, when its end is fixed to the header pipe, the heat exchange pipe in the vicinity of the header pipe mounting position is not as fixed. It becomes clear that the outstanding effect which can suppress damage is produced.
[0034]
【The invention's effect】
In the present invention, a rod-like body penetrating through the heat exchange pipe is also passed through the header pipe and fixed to the header pipe on the side opposite to the heat exchange pipe attachment side, thereby cutting the heat exchange pipe near the header pipe attachment position or It has an excellent effect of suppressing damage such as breakage.
It has also been found that by adopting such a structure and selecting the diameter of the rod-like body disposed in the heat exchange pipe within a specific range, it is possible to avoid the formation of deposits that are sometimes called scales. .
[Brief description of the drawings]
FIG. 1 is a side sectional view of a surface treatment apparatus of the present invention.
FIG. 2 is a plan view of the surface treatment apparatus of the present invention.
FIG. 3 is a front sectional view of the surface treatment apparatus of the present invention.
FIG. 4 is a partial side view of the heat exchange device of the present invention.
FIG. 5 is a diagram illustrating an example of a preferable structure of a heat exchange pipe fitting including a locking ring for preventing steam leakage and the like.
FIG. 6 is a view showing a tube spacer inserted into the heat exchange pipe at the position of the heat exchange pipe fitting.
FIG. 7 is a diagram illustrating the structure of a conventional heat exchange device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Surface treatment apparatus 2 Surface treatment tank 11 Heat exchange apparatus 12 Header pipe 15 Heat exchange pipe 21 Heat exchange pipe fixture 23 Rod-shaped body 24 Rod-shaped body latching tools 22, 25 Cap nut

Claims (7)

Two parallel header pipes having a large number of heat exchange pipe attachment holes along the long axis, a fluororesin heat exchange pipe having both ends attached to the attachment holes of the header pipe, and the inside of the pipe as the long axis of the pipe A heat exchange device comprising a rod-like body that penetrates along both ends and penetrates both ends in a direction orthogonal to the header pipe and is fixed to the header pipe on the side opposite to the mounting hole. The heat exchange device according to claim 1, wherein the fluororesin of the heat exchange pipe is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer or tetrafluoroethylene-hexafluoropropylene copolymer. The heat exchange device according to claim 1 or 2, wherein the rod-shaped body is a metal having corrosion resistance and conductivity. The heat exchange device according to claim 3, wherein the metal is stainless steel, titanium, or hastelloy. The surface treatment apparatus by the heat processing liquid equipped with the heat exchange apparatus of any one of Claim 1 thru | or 4 which suspended the heat exchange apparatus in the surface treatment tank. The surface treatment apparatus of Claim 5 which has arrange | positioned the heat exchange apparatus along the both sides of a surface treatment tank. The surface treatment apparatus according to claim 5 or 6, wherein a header pipe of a heat exchange device disposed on the center side of the surface treatment tank is used for supplying a heat medium.

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