JPS60144598A - Heat exchanger - Google Patents

Abstract

PURPOSE:To make it possible to suppress the thermal deformation of the heat transfer tube by inserting a rigid wire through the substantially entire length of the inside of the heat transfer tube formed by flexible plastics, in the titled heat exchanger for use in plating processing and the like. CONSTITUTION:In the heat exchanger 10, a large number of U-shaped heat transfer tubes 16 formed by flexible plastics such as a fluororesin or the like are provided between flow-in and flow-out manifolds 12 and 14 disposed in parallel through tube joints 18 and 20. Each of the heat transfer tubes 16 has a circular section, a hot fluid is passed therethrough to carry out heat exchange with a medical fluid within a fluid tank. In the interior of the heat transfer tube 16 is inserted a metal wire 22 or a rigid wire made of a glass fiber reinforced resin or the like to suppress the thermal deformation of the heat transfer tube 16. The metal wire 22 or the rigid wire is also used as a support member, and the interval between the heat transfer tubes is appropriately held. A capillarity occurs due to the rigid wire 22, and the discharge of the condensate within the tube is promoted, and the amounts of the distributed fluids become substantially equal. Furthermore, when a metal wire is used, it is made possible to discharge static electricity generated in the heat transfer tube.

Description

[Detailed Description of the Invention] The present invention relates to a heat exchanger, and specifically relates to a heat exchanger used in plating processing, metal processing, etc.
More particularly, the present invention relates to a heat exchanger having improved heating tubes.

Various heat exchangers of this type have been known in the past.

First, an immersion type heat exchanger is used in which a heat transfer tube made of a meandering metal tube is immersed in a plating bath or the like. This is because the metal tube is relatively thick and rigid, so it can be easily supported in the liquid. but,
The chemical solution used tends to cause corrosion and wear on the surface of the heat transfer tube.
In addition, there is a drawback that the chemical solution contaminates the heat exchanger tubes due to corrosion.

In order to prevent the above disadvantages, plastic pipes are sometimes used instead of metal pipes. This is a fluororesin,
Heat transfer tubes are made of flexible plastics such as polybutene and polypropylene, but (1) the tube diameter cannot be increased due to pressure resistance, and (2) it is difficult to maintain the shape by itself due to the flexibility of the material. There are some drawbacks.

In other words, in this type of heat exchanger, due to the above (1), many thin tube-shaped heat transfer devices are generally used, and in that case, due to the above (2), these The heat exchanger tubes come into contact with each other and slide due to thermal deformation, causing wear and breakage of the heat exchanger tubes.

In addition, plastic heat exchanger tubes have a low specific gravity, so
If the tube is not filled with liquid, there is a high possibility that -2- will float to the surface.

In order to eliminate the above disadvantages of plastic jaw heat exchanger tubes, it is necessary to fix the heat exchanger tubes in place. As an example, the apparatus shown in FIGS. 9 to 11 is used. In other words, two pairs of brackets (4) (4), (5) < 5) are placed above the liquid (3) from the peripheral wall (2) of the liquid tank (1).
, are protrudingly provided, and a pair of manifolds (6) (6) are provided on the inflow side and the outflow side, respectively, across these brackets.
, (7) (7) is installed. Between the two corresponding sets of manifolds (6) (7), (6) and (7), a plurality of U-shaped heat exchanger tubes (8) arranged in parallel inside and outside are connected to a pipe joint (9).
It is arranged through. 2111 manifold (6
) (7) further includes a U-shaped hanging material (10) made of a rigid body such as a metal wire and whose outer surface is coated with a corrosion-resistant material such as a bracket material, as shown in FIG.
They are placed inside and outside. The hanging material (1o) has rectangular plate-shaped spacers (11) arranged at equal intervals along its entire length.
, thereby fixing the base plate (11) in a predetermined position. This spacer (11) has each row of small holes (1
2), and each of the heat exchanger tubes (8) passes through each of the small holes (12).

Since the heat exchanger tubes are restrained by the spacer (11) in this way, it is possible to prevent the heat exchanger tubes from coming into contact with each other and floating up. However, this structure still has the following drawbacks.

(1) Plastic tubes often bend due to thermal deformation and come into contact with adjacent heat transfer tubes, making them prone to wear.

(2) Due to the flow of the liquid, the heat transfer tube slides against the spacer and wears out. Particularly when solids are included in the liquid, wear is large.

(3) The entire structure including spacers, hanging materials, etc. is complex, which promotes scaling.

In consideration of the above drawbacks, heat exchangers shown in FIGS. 12 to 14 have been conventionally used.

As shown in FIG. 12, this has a heat exchanger tube whose outer surface of a metal tube (15) is coated with a corrosion-resistant material (1B) such as plastic. 13 and 14 show a heat exchanger in which a plurality of U-shaped heat exchanger tubes are arranged side by side.

In this type, the rigidity of the heat exchanger tube is high, and the
Unlike the conventional example, it does not require hanging materials or spacers, so it is very effective in preventing wear. On the other hand, since it is difficult to process plastic coatings, (1) the cost is low, (2) it is difficult to make long heat exchanger tubes, and the number of pipe joints is large (the installation space is large). I don't get it.

The heat exchanger tubes described above have further drawbacks. First, in the case of a type in which a plurality of heat transfer tubes are attached to a manifold, there is a risk that the fluid in the tubes may short-circuit. The reason for this is that if the heat transfer tubes are not very long, the fluid resistance is quite small. Therefore, if the diameter of the manifold cannot be increased, the dynamic pressure within the manifold cannot be sufficiently reduced, and many It is difficult to evenly distribute the flow to the heat tubes.

-5- In particular, when passing steam through a pipe, there is a high possibility of short circuiting. That is, during use, condensate (11) is placed at the bottom of a specific heat transfer tube as shown in Figure 15.
may accumulate and block the steam flow path. Since the heat load per heat transfer tube is slightly different, this phenomenon is not uncommon. As mentioned above, the fluid resistance inside the heat transfer tubes is extremely small, and the internal pressures in the steam inlet and outlet manifolds are almost the same.
Therefore, steam is difficult to flow through the heat exchanger tubes sealed with condensate, and instead flows selectively through the tubes where there is no condensate retention and resistance is low, causing a short circuit. Retention of condensate spreads to other heat exchanger tubes one after another, and most of the tubes may become blocked. In addition, the amount of accumulated water gradually increases until the pipe is almost filled.

The above phenomenon hardly occurs when the inner diameter of the heat exchanger tube is very small (for example, 2III) or when the tube is relatively thick but long (for example, the inner diameter is F3 gi (tube length: 30 m)), but the heat exchanger tube The inner diameter is relatively thick and short (
For example, if a plurality of tubes (with an inner diameter of about 6 to 12 mm and a length of about 10 m or less) are used, the above phenomenon is likely to occur and there is a risk of functional impairment.

In view of the above-mentioned points, the inventor of the present invention achieved the following by inserting a rigid wire made of a metal wire or the like into the inside of a plastic heat exchanger tube.
(1) The above disadvantages due to the flexibility of plastic,
(2) It has been found that the occurrence of short circuits can be prevented.

In other words, by inserting a rigid wire inside a flexible plastic heat exchanger tube, the heat exchanger tube can maintain its own shape, and by inserting a rigid wire with a predetermined diameter into the inside of the heat exchanger tube, By providing this resistance, variations in resistance among the plurality of heat exchanger tubes can be reduced, thereby preventing the occurrence of short circuits.

Next, preferred embodiments of the present invention will be described based on the accompanying drawings.

In FIGS. 1 to 5, one embodiment of this invention 7- An example (a multi-tubular hanging type heat exchanger) is shown.

10 shows the whole heat exchanger according to this embodiment, and this heat exchanger 10 has a large number of U-shaped heat exchanger tubes 16 connected to pipe joints 18 . It is attached via 20. Thus, the heat exchanger tube 16 has a circular cross section, and the metal wire 22 is inserted into the inside thereof. Instead of the metal wire 22, a rigid material such as glass fiber reinforced plastic may be used.

FIG. 3 and FIG. 4 show details of the joint structure with the heat exchanger tubes 16 in the inflow side manifold 12 and the discharge side manifold 14.

First, the inflow side manifold 12 has a number of mounting screw holes 24 corresponding to the number of heat exchanger tubes 16 bored at equal intervals in the axial direction on the lower surface of the manifold 12 having a circular diameter cross section. A connecting member 26 having a male thread on the upper outer peripheral surface is screwed into the screw hole 24 . Connecting member 2
4 has a hollow hole inside, the diameter of which becomes slightly larger at the center position in the vertical direction, and forms a stepped portion 28. Connecting member 2
6 further has a male threaded portion 27 on its lower outer circumferential surface, and a bottomed cylindrical nut 12 is tightened and fixed to this male threaded portion 21.

The upper end of the heat exchanger tube 16 is inserted into the connecting member 26 until it comes into contact with the stepped portion 28 , and at this time, a ring 30 is inserted around the outer periphery of the connecting tube near the upper end of the heat exchanger tube 16 .

The cross-sectional shape of the tightening ring 30 is as clearly shown in FIG. The attachment has a shape corresponding to the cross-sectional shape of the nut 21. With this structure, the nut 27 is tightened, and the upper end of the ring 30, in particular, is pressed inward in the radial direction and the heat exchanger tube 16 is tightened. It bites into the outer peripheral surface and reliably prevents the heat exchanger tube 16 from being pulled out.In addition, in this bearing 18, the upper end of the metal wire 22 extends slightly above the upper end of the heat exchanger tube 1B.

FIG. 4 shows the mounting state of the joint 20 on the discharge side manifold 14. This is basically the same as the joint 18 in the inflow side manifold, but the upper inner diameter of the connecting member 28 is smaller than that in the inflow side manifold, and the upper end of the metal wire 22 is connected to the manifold 1.
It differs in that it extends into the interior of 4.

The heat exchanger of the above embodiment is suspended and held in the state shown in FIG. 1 in a liquid tank (not shown) storing a chemical solution, etc., and the thermal fluid is passed through the inflow side manifold 12 to each heat transfer tube. 16
The hot fluid is passed through the inside, and heat exchange is performed on the chemical solution and the like within the liquid tank, and then the hot fluid is discharged to the outside of the apparatus via the discharge manifold 14.

Although the cross section of the metal wire has a circular diameter in the above embodiment, it may have a shape other than this. Moreover, if the surface of the metal wire is coated with a corrosion-resistant material, it is also possible to flow a corrosion-resistant fluid into the inside of the heat exchanger tube.

As mentioned above, since this heat transfer tube is made of plastic such as fluororesin, it is necessary to prevent harmful effects such as corrosion of the heat transfer tube surface due to the chemical used, wear, and contamination of the chemical due to melting of the heat transfer tube. I can do it. In addition, due to the flexibility of the plastic material, it is possible to mold it into the required shape even after inserting the metal wire, and it is also possible to insert the metal wire formed into the required shape into the heat exchanger tube. be.

Since the metal wire is inserted into the plastic heat exchanger tube in this manner, the heat exchanger tube is supported by the metal wire, and thermal deformation of the tube can also be reduced. When the total length of the heat exchanger tube is relatively short, the spacer used in the prior art becomes unnecessary. Therefore, it is very useful for preventing wear and tear, and is also considerably cheaper than a metal tube coated with plastic or the like.

Furthermore, since the metal wire is inserted inside the heat exchanger tube, the resistance of the heat exchanger tube is considerably large and almost uniform. Therefore, even if condensate temporarily remains in a specific pipe, the rate of increase in resistance due to this is small;
The stagnant condensate moves downstream and is removed.

-11- In addition, capillarity acts between the inner circumferential surface of the heat exchanger tube and the inserted metal wire, making it easier to discharge condensate.

In addition, when the J: sea urchin metal wA4 shown in FIG. This further reduces the loss of steam released outside the pipe. This type of steam trapping does not impede the exit of non-condensable gas I3+.

In addition, when the fluid inside the tube is liquid, the inserted metal wire provides appropriate resistance, improving liquid distribution from the manifold to each heat transfer tube. It goes without saying that the wire diameter should be determined so that fluid resistance does not become too large.

By the way, static electricity is generated when highly dry saturated steam or superheated steam is passed through plastic pipes. Static electricity is harmful because it can penetrate through thin-walled plastic pipes and discharge to the outside, even destroying the pipe walls. In that case, if the manifold is grounded, static electricity will be discharged from the manifold via the metal wire and pipe joint. In this case, as shown in FIG. 6, the metal wire 22 is not held at the center of the flow path and has a high possibility of coming into contact with the pipe fitting 20, thereby achieving the above effect.

FIG. 7 shows an embodiment in which the heat exchanger of the present invention is used in a side insertion type. That is, 144 is a side wall of a storage tank for a chemical solution, and the side wall 144 is connected to a chamber 148 via a flange portion 146. The chamber 148 is defined by an upper fluid inlet channel 150 and a lower fluid outlet channel 152, both of which have fluid inlets and outlets 1, respectively.
54 and 156. 158 is chamber 1
48 and the flange 146 of the storage tank, the tube sheet 158 holds both ends of the U-shaped heat transfer tube 116, and the heat transfer tube 116 is held in a horizontal position within the storage layer by the metal wire 122. It is maintained at It is also possible to provide heat exchanger tubes on the bottom or top of the reservoir, similar to the structure of the previous embodiment.

FIG. 8 shows still another embodiment in which the heat exchanger tube according to the present invention is used in a shell-and-dupe heat exchanger. In this embodiment, an inlet channel 162 and an outlet channel 164 are arranged on the left and right sides of the shell 160, and are provided with inlet and outlet holes 166 and 168 for fluid, respectively. 16
Reference numerals 9 and 170 indicate inflow holes and discharge holes for the chemical solution provided at the top and bottom of the shell. Inside the shell 160, a plurality of straight heat exchanger tubes 116 are arranged in parallel between the tube sheets 172, 174. 122 is a metal wire provided inside each heat exchanger tube, and is fixed to the tube sheet by appropriate means. The presence of the metal wire 122 allows the heat exchanger tube 116 to be held substantially in a straight line despite its flexibility.

As described above, the present invention provides a heat exchanger having flexible plastic heat exchanger tubes over almost the entire length of the heat exchanger tubes, by inserting a rigid wire into the inside of the heat exchanger tubes over almost the entire length of the heat exchanger tubes. It serves as a support material for the heat exchanger tubes and also maintains the distance between the heat exchanger tubes, thereby suppressing deformation of the shape of the heat exchanger tubes due to heat.

-14- This eliminates the need for an extra-tube support material for the heat exchanger tube, which was conventionally required, and drastically reduces the number of tubes to be worn.

Furthermore, since the rigid wire is inserted into the heat exchanger tube, it provides resistance and causes capillarity, which promotes discharge of condensate within the heat exchanger tube and prevents short circuits of the fluid within the heat exchanger tube. Furthermore, by inserting the rigid wire into the heat transfer tube, the fluid resistance increases, so that the respective fluid pressures within the heat transfer tube are approximately equal, and the distributed fluid amounts are approximately equal.

Since the flow path is narrowed by the rigid wire at the end of the heat exchanger tube, a reduction in steam release loss due to the steam trapping effect is expected.

If the rigid wire is made of metal, the static electricity generated in the heat exchanger tube can be released by bringing the end of the rigid wire inserted into the heat exchanger tube into contact with a metal fitting used at the end of the heat exchanger tube. .

[Brief explanation of drawings]

Fig. 1 is a perspective view of the hanging type heat exchanger tube of this example, Fig. 2 is a partially cutaway perspective view showing the inside of the heat exchanger tube, and Fig. 3 is a perspective view of the inflow manifold and pipe joint. Figure 4 is a cross-sectional view along the line ■--■ showing the connection structure of the heat exchanger tubes, Figure 4 is a cross-sectional view along the rv-rv line showing the connection structure between the discharge manifold, the pipe joint, and the heat exchanger tube, and Figure 5 is the internal structure of the pipe joint. FIG. 6 is a cross-sectional view showing a state in which a metal wire is in contact with a pipe joint; FIG. 7 is a schematic diagram showing the internal structure of a side-inserted heat exchanger tube; FIG. 9 is a schematic diagram showing the internal structure of a shell-and-tube heat exchanger, FIG. 9 is a schematic diagram of a conventional hanging heat exchanger tube, FIG. 10 is a side view of the upper part of FIG. 9, and FIG. The figure is a plan view of a spacer. Figure 12 is a sectional view of a heat exchanger tube made of a metal tube coated with synthetic resin. -16- Figure 13 shows the above heat exchanger tube used as a hanging type heat exchanger tube. A schematic diagram, FIG. 14 is a side view of FIG. 13, and FIG. 15 is a cross-sectional view showing condensate retained in a conventional heat exchanger tube. Explanation of symbols 22.122... Heat exchanger tube 16.116... Rigid wire -17- Figure 5 Figure 6 Figure 10 Figure 9 Procedure amendment (formula 1982 January 2, 1, Case indication 1982 Patent Application No. 250720 2 Name of the invention Heat exchanger 3 Person making the amendment Related to the case Patent applicant Kansetsu Sangyo 2-22-2 Isoji, Minato-ku, Osaka City Co., Ltd. Representative: Hitoshi Nomura 4, Agent: 8th floor, Handa Building, 2-9 Jusei, Higashi-ku, Osaka 541 (
06-227-5535) August 7, 1980 6, Number of inventions increased by 7 due to amendment, 8 drawings subject to amendment, Contents of amendment: Engraving of drawings (no change in content) C8^

Claims (1)

[Claims] 1. Heat exchanger tube (16:
116).