JP2017009265A - Multi-pipe type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-pipe type heat exchanger having a small number of components for a heat transfer pipe, capable of being easily assembled, and preventing flow of process fluid from being accumulated at a communication portion between a going heat transfer pipe and a returning heat transfer pipe.SOLUTION: A multi-pipe type heat exchanger 1 for performing heat exchange between heat medium and process fluid, provides a pipe plate 10 at both ends of a shell 20; installs a plurality of heat transfer pipes 31, 32 in a multistage manner in the pipe plate 10 and stores them in the shell 20; forms the heat transfer pipes 31, 32 as a communication heat transfer pipe 30 communicating with each other outside the shell 20 by a curved pipe 50, which is a single and integrally molded casting; injects fluid as the heat medium into the shell 20; circulates the process fluid in the communication heat transfer pipe 30; and performs heat exchange between the heat medium in the shell 20 and the process fluid.SELECTED DRAWING: Figure 1

Description

  The present invention is provided with tube plates at both ends of the shell, and a plurality of return heat transfer tubes and return heat transfer tubes are installed between the tube plates and housed in the shell, and a fluid as a heat medium is injected into the shell, The present invention relates to a multi-tube heat exchanger in which a process fluid is injected into a heat transfer tube to exchange heat between the fluids.

  Conventionally, a heat exchanger such as a tube type or a plate type has been used as a heat exchanger for heating and cooling and sterilizing process fluids such as foods, pharmaceuticals, and cosmetics. Process fluids range from low viscosity to high viscosity. Furthermore, there are various process fluids including those of slurry fluids containing solids and fluids having non-Newtonian characteristics. In particular, as a heat exchanger used for a process fluid having a relatively low viscosity such as a beverage, a plate-type or multi-tube type heat exchanger is used.

Among such heat exchangers, there is a multi-tube heat exchanger as shown in Patent Document 1, for example.
In other words, a plurality of return heat transfer tubes and return heat transfer tubes are installed on the channel cover plate, and the return heat transfer tubes and the return heat transfer tubes are communicated with each other by a U-shaped tube composed of two pipes outside the channel cover plate. It is. More specifically, the U-shaped tube is abutted in a state in which two pipes having the same diameter are bent at a predetermined angle and then each bent portion is appropriately cut and the cut surfaces are brought into contact with each other. The part is welded.

Japanese Patent No. 3374345

  However, in such a conventional technique, in manufacturing a U-shaped pipe, a process of bending each of two pipes (straight pipes) at a predetermined angle, and a bent portion of each of the two bent pipes are cut at predetermined positions. A step of contacting the cut surfaces of the two cut pipes, a step of welding the contact portion while keeping the contacted state, a step of polishing the welded portion, and the like. As described above, the manufacture of the U-shaped tube requires many steps, and there is a problem that it takes time and costs.

  In addition, there is a problem that a sanitary property is liable to occur because a step, a bulge of welding, or the like remains in a connection portion that is connected by welding.

  The present invention has been made paying attention to such problems of the prior art, and does not require many steps for forming a bent tube such as a U-shaped tube, and has a short manufacturing time and a low manufacturing cost. U-tubes have excellent cleanability because the inner wall has a smooth surface without requiring a special process such as a polishing process. The purpose is to provide a few multi-tube heat exchangers.

The gist of the present invention for achieving the object lies in the inventions of the following items.
[1] A plurality of heat transfer tubes (31, 32) are laid in multiple stages between the tube plates (10) provided at both ends of the shell (20) and housed in the shell (20), and the heat transfer tubes (31 , 32) is communicated outside the shell (20), a fluid as a heat medium is injected into the shell (20), and the plurality of heat transfer tubes (31, 32) communicate with each other. 30) In a multi-tube heat exchanger (1) in which a process fluid is circulated in the heat exchanger to exchange heat between the process fluid and the heat medium,
A lid plate (40) joined to the tube plate (10);
The end portions of the plurality of heat transfer tubes (31, 32) installed on the tube plate (10) are attached to the cover plate (40) so as to communicate outside the cover plate (40). A bent tube (50);
With
The multi-tube heat exchanger (1), wherein the bent pipe (50) is a single integrally formed casting.

[2] The bent pipe (50) is a 180 ° U-shaped pipe where R / D = 1 when the outer diameter of the pipe is D and the bending radius is R.
An injecting nozzle (310) for injecting the process fluid is provided in the most upstream heat transfer tube of the communication heat transfer tubes (30), and a discharge nozzle for discharging the process fluid injected into the communication heat transfer tube (30) ( 320) is provided in the most downstream heat transfer pipe among the communication heat transfer pipes (30), and the process fluid flows naturally from the most upstream heat transfer pipe to the most downstream heat transfer pipe. The multi-stage heat exchanger (1) according to item [1], wherein the multi-stage heat exchanger (1) is arranged.

[3] The heat transfer tube seal gasket (71) that individually surrounds each of the plurality of heat transfer tubes (31, 32), and the outer peripheral seal gasket (72) that collectively surrounds the communication heat transfer tube (30). Arranged to be sandwiched between the tube plate (10) and the lid plate (40),
An injection part (61) for injecting various fluids into a gap (100) formed between the heat transfer tube seal gasket (71) and the outer peripheral seal gasket (72), and discharging various fluids from the gap (100). The multi-tube heat exchanger (1) according to item [2], wherein the discharge section (62) is provided to prevent external contamination.

[4] The pressure resistance of the sealing by the heat transfer tube seal gasket (71) is larger than the pressure resistance of the sealing by the outer peripheral seal gasket (72),
The multi-tube heat exchanger (1) according to item [2] or [3], wherein various fluids injected into the gap (100) are prevented from entering the shell (20).

The present invention operates as follows.
The multi-tube heat exchanger (1) allows the fluid serving as a heat medium to be injected, circulated, and discharged in the shell (20) to the outside of the communication heat transfer tube (30), and in the communication heat transfer tube (30), a process is performed. Inject, distribute, and discharge fluid. This allows heat exchange between the process fluid and the heat medium.

  Since both ends of the shell (20) are sealed by the tube sheet (10), the heat medium injected into the shell (20) does not leak out of the shell (20). The communication heat transfer tube (30) extending into the shell (20) is connected to a bent tube (50) extending outside the lid plate (40) and making a U-turn. Therefore, the process fluid flowing in the communication heat transfer tube (30) in the shell (20) temporarily goes out of the shell (20) while flowing in the bent tube (50) extending outside the cover plate (40). It flows again into the communicating heat transfer tube (30) in the shell (20).

  In the bent pipe (50), when the outer diameter of the pipe is D and the bending radius is R, when the bent pipe (50) is a 180 ° U-shaped pipe where R / D = 1, the passing process fluid has a stirring effect. As a result, the heat transfer coefficient is increased, so that heat exchange with the heat medium is performed better.

  An injection nozzle (310) for injecting the process fluid is provided in the most upstream heat transfer tube of the communication heat transfer tubes (30), and a discharge nozzle (320) for discharging the process fluid injected into the communication heat transfer tubes (30). Is provided in the most downstream heat transfer tube of the communication heat transfer tube (30), and the communication heat transfer tube (30) is arranged so that the process fluid naturally flows from the most upstream heat transfer tube to the most downstream heat transfer tube. Therefore, the process fluid flows without stagnation through the communication heat transfer tube (30).

  Between the tube plate (10) and the cover plate (40), the heat transfer tube seal gasket (71) individually enclosing each of the plurality of heat transfer tubes (31, 32) and the entire communication heat transfer tube (30) are provided. An outer peripheral sealing gasket (72) surrounding the bulk is disposed.

  The tube plate (10) and the cover plate (40) are formed such that a slight gap (100) is formed between them when they are joined. A portion of the gap (100) closer to the outer peripheral edge than the outer peripheral seal gasket (72) and a portion between the outer peripheral seal gasket (72) and the heat transfer tube seal gasket (71) are isolated by the outer peripheral seal gasket (72). Has been.

  In the gap (100), a portion formed between the heat transfer tube seal gasket (71) and the outer peripheral seal gasket (72) is filled with various fluids such as steam, sterile air, or a sealing fluid from the injection portion (61). Can be injected. Various fluids in the gap (100) can be discharged to the outside through the discharge part (62). As a result, the inside of the shell can be prevented from being exposed to external contamination.

  In addition, since the pressure resistance of the sealing by the heat transfer tube seal gasket (71) is set larger than the pressure resistance of the sealing by the outer peripheral seal gasket (72), various fluids injected into the gap (100) are transferred to the heat transfer tube seal gasket ( 71) and entering the inside of the shell (20) can be prevented.

According to the multi-tube heat exchanger according to the present invention, since the bent tube attached to the lid plate is a single integrally formed casting, the manufacturing process is greatly reduced, and the manufacturing cost is reduced. Can do.
Moreover, since there is no connection part in a bending pipe, an inner wall surface can be made smooth, and thereby it can have good cleaning properties and excellent sanitary properties.

It is a side view which shows the principal part of the multitubular heat exchanger which concerns on one embodiment of this invention. It is a mimetic diagram showing the outline seen from the side of the multi-tube type heat exchanger concerning one embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
Each figure shows an embodiment of the present invention. FIG. 1 is a side view showing a main part of the invention in a multi-tube heat exchanger according to an embodiment of the present invention, and FIG. 2 is a multi-tube heat exchange according to an embodiment of the present invention. It is a schematic diagram which shows the outline when a container is seen from a side surface direction.

  As shown in FIG. 2, the multi-tube heat exchanger 1 has the tube plate 10 tightly fixed to both ends of the shell 20 to block the inside of the shell 20 from the external environment. Between the tube plates 10 at both ends, a plurality of return heat transfer tubes 31 and return heat transfer tubes 32 are installed and accommodated in the shell 20. The plurality of return heat transfer tubes 31 and the return heat transfer tubes 32 are connected by a U-shaped tube 50 to be described later, and constitute a communication heat transfer tube 30 that communicates.

  A process fluid injection nozzle 310 for injecting a process fluid is provided in the most upstream return heat transfer tube 31 of the communication heat transfer tube 30. Further, a process fluid discharge nozzle 320 for discharging the process fluid is provided in the most downstream return heat transfer tube 31 of the communication heat transfer tube 30. The process fluid referred to here is a fluid in food, medicine, cosmetics and the like. The communication heat transfer tube 30 is provided with an inclination so that the process fluid injected from one end of the uppermost stream naturally flows down to one end of the lowermost stream.

  On the other hand, a heat medium injection nozzle 210 for injecting a fluid as a heat medium into the inside of the shell 20 extends upward. In addition, a heat medium discharge nozzle 220 for discharging the heat medium from the inside is extended downward at the other end. As described above, the return heat transfer pipe 31 and the return heat transfer pipe 32 are provided inside the both ends of the shell 20.

  The tube plate 10 has a plurality of through holes, and one end of the return heat transfer tube 31 or the return heat transfer tube 32 passes through these through holes. A lid plate 40 is joined to the tube plate 10 on the outside. The lid plate 40 is fixed to the tube plate 10 with bolts and nuts.

  The lid plate 40 is provided with a joint hole penetrating at each position overlapping the through hole formed in the tube plate 10 in a state of being joined to the tube plate 10. A tube end portion of a U-shaped tube 50, which is a metal bent tube, is fitted into each joint hole of the lid plate 40 from the outside. The illustrated U-shaped tube 50 is a 180 ° U-shaped tube made of stainless steel. The U-shaped tube 50 and the lid plate 40 are fixed by welding. The U-shaped tube 50 is a so-called 1DR U-shaped tube in which R / D = 1 when the 180 ° bent portion is D and the bending radius is R.

  The inner diameters of the U-shaped tube 50, the return heat transfer tube 31 and the return heat transfer tube 32 constituting the communication heat transfer tube 30 are the same. The inner diameter of the U-shaped tube 50 is the same as the inner diameter of the communication heat transfer tube 30. The inner diameter of each joint hole of the cover plate 40 has a two-stage configuration with different sizes. The inner diameter of the portion closer to the outside where the U-shaped tube 50 is fitted is substantially the same as the outer diameter of the U-shaped tube 50. The inner diameter of the portion deeper than this portion, that is, the portion closer to the tube plate 10 is the same as the inner diameter of the U-shaped tube 50 and the communication heat transfer tube 30.

  One end of the U-shaped tube 50 fitted into the cover plate 40 is connected to one end of either the return heat transfer tube 31 or the return heat transfer tube 32, and the other end of the U-shaped tube 50 is the return heat transfer tube 31 or the return heat transfer tube. The other end of 32 is connected. Therefore, the return heat transfer tube 31 and the return heat transfer tube 32 installed on the tube plate 10 communicate with each other via the U-shaped tube 50 outside the shell 20.

  The U-shaped tube 50 is an integrally molded casting. Thereby, since the U-shaped tube 50 does not have a connecting portion like the conventional U-shaped tube, the inner wall is formed in a smooth surface. The U-shaped tube 50 is fixed to the lid plate 40 by welding. Therefore, the U-shaped tube 50 and the cover plate 40 are a combination of materials that can be welded. Usually, the U-shaped tube 50 and the cover plate 40 may be made of the same material.

  A slight gap 100 is formed on the joint surface between the joined tube plate 10 and the cover plate 40. Various fluids such as steam, sterile air, or a sealing fluid are injected into the gap 100 to prevent contamination.

  The gap 100 is provided with an aseptic injection nozzle 61 for injecting various fluids from the outside. An aseptic discharge nozzle 62 for discharging various fluids from the gap 100 to the outside is also provided. The aseptic injection nozzle 61 is provided with an on-off valve 63 for starting and stopping injection of fluid. The aseptic discharge nozzle 62 is provided with a pressure adjusting valve 64 for discharging the fluid injected into the gap 100 and adjusting the pressure in the gap 100.

  A plurality of heat transfer tube seal gaskets 71 having a larger diameter than the return heat transfer tube 31 and the return heat transfer tube 32 and individually surrounding each of the plurality of return heat transfer tubes 31 and the return heat transfer tubes 32 are disposed in the gap 100. ing. Further, one outer peripheral seal gasket 72 that surrounds the entire communication heat transfer tube 30 is provided.

  The outer peripheral seal gasket 72 is arranged to be a circle having a diameter larger than the outer diameter of the shell 20. The heat transfer tube seal gasket 71 and the outer peripheral seal gasket 72 are disposed so as to be sandwiched between the tube plate 10 and the cover plate 40. The aseptic injection nozzle 61 and the aseptic discharge nozzle 62 are connected to the gap 100 in the portion between the heat transfer tube seal gasket 71 and the outer peripheral seal gasket 72, respectively.

  The pressure resistance of the sealing by the heat transfer tube seal gasket 71 is set larger than the pressure resistance of the sealing by the outer peripheral seal gasket 72. Therefore, when the pressure of the fluid injected from the heat transfer tube seal gasket 71 into the gap 100 increases, the fluid starts to leak from the outer peripheral seal gasket 72 side. For this reason, fluid does not leak to the heat transfer tubes 31 and 32 surrounded by the heat transfer tube seal gasket 71. As a result, the fluid injected into the gap 100 does not enter the shell 20 side.

Next, the operation will be described.
The multi-tube heat exchanger 1 is housed in the shell 20, and a fluid serving as a heat medium is in contact with the outer peripheral surface of the communication heat transfer tube 30 in which the return heat transfer tube 31 and the return heat transfer tube 32 are communicated by the U-shaped tube 50. In such a manner, the heat medium is injected into the shell 20, distributed, and discharged. A process fluid is injected, circulated, and discharged into the communication heat transfer tube 30. As a result, the process fluid in the communication heat transfer tube 30 and the heat medium outside the communication heat transfer tube 30 can exchange heat via the tube wall of the communication heat transfer tube 30.

  A heat medium is injected from the heat medium injection nozzle 210 into the shell 20 whose both ends are sealed by the tube plate 10. Since the tube sheet 10 is tightly fixed to the shell 20, the injected heat medium does not leak out of the shell 20. The heat medium injected into the shell 20 can be discharged from the heat medium discharge nozzle 220 to the outside of the shell 20.

  The process fluid that is injected into the communication heat transfer tube 30 in the shell 20 to exchange heat with the heat medium in the shell 20 can be injected into the communication heat transfer tube 30 from the process fluid injection nozzle 310. In addition, the process fluid that has undergone the heat exchange process can be discharged from the communication heat transfer tube 30 through the process fluid discharge nozzle 320.

  Thereby, heat is exchanged between the process fluid and the heat medium via the communication heat transfer tube 30. One end of the U-shaped pipe 50 connected to one end of the return heat transfer pipe 31 is exchanged with the heat medium in the shell 20 while the process fluid injected into the return heat transfer pipe 31 from the process fluid injection nozzle 310. Flows into the U-shaped tube 50.

  Since the U-shaped tube 50 is provided outside the shell 20, the process fluid does not exchange heat while traveling through the U-shaped tube 50. The process fluid that has traveled through the U-shaped tube 50 flows into the return heat transfer tube 32 from one end of the lower-stage return heat transfer tube 32 connected to the other end of the U-shaped tube 50. Since the return heat transfer tube 32 is disposed in the shell 20, the process fluid flowing through the return heat transfer tube 32 enters the shell 20 again and communicates with the heat transfer medium in the shell 20 through the communication heat transfer tube 30. The heat exchange via is resumed.

  The process fluid that has traveled through the return heat transfer tube 32 to the other end travels through the U-shaped tube 50 and then flows into the return heat transfer tube 31 that is one step below. In this way, the process fluid flows down to the most downstream in the communication heat transfer tube 30.

  Since the U-shaped tube 50 is a single casting that is integrally formed, it is formed on a smooth surface that does not have a bulge, a step, or the like that forms a joint on the wall surface in the tube. Thereby, the U-shaped tube 50 has excellent internal cleanability, and the sanitary property of the multi-tube heat exchanger 1 is improved. Further, the process fluid can smoothly flow through the U-shaped tube 50. The process fluid that has traveled through the communication heat transfer tube 30 and reached the process fluid discharge nozzle 320 is discharged from the process fluid discharge nozzle 320.

  Inside the shell 20, the tube plate 10 is tightly fixed at both ends, but in the gap 100 formed between the cover plate 40 and the tube plate 10 joined to the tube plate 10 outside the tube plate 10. Can inject various fluids. The various fluids are, for example, steam, aseptic air, sealing fluid, or the like. Thereby, the inside of the shell 20 can be isolated from the external environment of the shell 20. Therefore, the inside of the shell 20 can be prevented from being contaminated by contaminants from the external environment.

  Such a fluid has a gap 100 between a heat transfer tube seal gasket 71 that individually surrounds each of the plurality of return heat transfer tubes 31 and the return heat transfer tube 32 and an outer peripheral seal gasket 72 that surrounds the entire communication heat transfer tube 30. Is injected from the aseptic injection nozzle 61. Since the aseptic injection nozzle 61 is provided with the on-off valve 63, the injection can be started and stopped by operating the on-off valve 63, and the amount of fluid injected can be adjusted.

  The fluid injected into the gap 100 can be discharged from the aseptic discharge nozzle 62. The discharge can be performed by opening the pressure regulating valve 64. Further, the pressure in the gap 100 can be adjusted by adjusting the pressure adjusting valve 64.

  The pressure resistance of the sealing by the heat transfer tube seal gasket 71 is set to be larger than the pressure resistance of the sealing by the outer peripheral seal gasket 72. The pressure in the gap 100 is set to be slightly smaller than the pressure resistance of the outer peripheral seal gasket 72. Thereby, there is no possibility that the fluid in the gap 100 leaks from the heat transfer tube seal gasket 71 and enters the inside of the shell 20, and contamination inside the shell 20 can be prevented.

  When the pressure in the gap 100 rises to a level that exceeds the pressure resistance of the outer peripheral seal gasket 72, the outer periphery of the heat transfer tube seal gasket 71 reaches the outer periphery before reaching a pressure that allows fluid to enter the shell 20. Fluid leaks out of the gap 100 from the seal gasket 72. Thereby, it is possible to prevent the fluid from entering the inside of the shell 20 from the portion of the heat transfer tube seal gasket 71.

  The embodiments of the present invention have been described above with reference to the drawings. However, the specific configuration is not limited to the above-described embodiments, and the present invention can be changed or added without departing from the scope of the present invention. Included in the invention. For example, in the example illustrated in FIG. 2, the process fluid injection nozzle 310 is disposed on one side of the longitudinal direction of the shell 20, and the process fluid discharge nozzle 320 is disposed on the other side. May be disposed below the same side as the process fluid injection nozzle 310. That is, the most downstream heat transfer tube of the communication heat transfer tube 30 may be the return heat transfer tube 32, and the process fluid discharge nozzle 320 may be provided in a part of the return heat transfer tube 32.

  The process fluid injection nozzle 310 is concentrically connected to the uppermost tube end of the communication heat transfer tube 30, and the process fluid discharge nozzle 320 is concentrically connected to the most downstream tube end of the communication heat transfer tube 30. Although not provided concentrically, the process fluid injection nozzle 310 is connected so as to communicate with the vicinity of the uppermost stream end of the communication heat transfer tube 30 from above, and the most downstream tube of the communication heat transfer tube 30 from below. The process fluid discharge nozzle 320 may be connected so as to communicate with the vicinity of the end.

  In the present invention, a multi-tube heat exchanger having a return heat transfer tube and a return heat transfer tube in a single shell is taken as an example, and a cast 180 ° U-shaped tube integrally formed as a bent tube is provided. As described above, a plurality of shells are connected in parallel or in series, and heat transfer tubes extending in the shells are connected by a 180 ° U-tube or a bent tube different from the 180 ° U-tube. The present invention can also be widely applied to a tube heat exchanger.

DESCRIPTION OF SYMBOLS 1 ... Multi-tube type heat exchanger 10 ... Tube plate 20 ... Shell 30 ... Communication heat transfer tube 31 ... Return heat transfer tube 32 ... Return heat transfer tube 40 ... Cover plate 50 ... U-shaped tube (flexible tube)
61 ... Aseptic injection nozzle 62 ... Aseptic discharge nozzle 63 ... On-off valve 64 ... Pressure regulating valve 71 ... Heat transfer tube seal gasket 72 ... Outer seal gasket 100 ... Gap 210 ... Heat medium injection nozzle 220 ... Heat medium discharge nozzle 310 ... Process Fluid injection nozzle 320 ... Process fluid discharge nozzle

Claims (4)

A plurality of heat transfer tubes are laid in multiple stages between tube plates provided at both ends of the shell and housed in the shell, and the heat transfer tubes communicate with the outside of the shell, and a fluid serving as a heat medium in the shell In a multi-tube heat exchanger in which a process fluid is circulated in the communication heat transfer tube in which the plurality of heat transfer tubes are communicated, and heat is exchanged between the process fluid and the heat medium.
A lid plate to be joined to the tube plate;
A bent tube attached to the lid plate, wherein the ends of each of the plurality of heat transfer tubes installed on the tube plate communicate with each other outside the lid plate;
With
The multi-tube heat exchanger is characterized in that the bent pipe is a single integrally formed casting. The bent tube is a 180 ° U-shaped tube where R / D = 1 when the outer diameter of the tube is D and the bending radius is R.
An injection nozzle for injecting the process fluid is provided in the most upstream heat transfer tube of the communication heat transfer tubes, and a discharge nozzle for discharging the process fluid injected into the communication heat transfer tube is provided in the most downstream of the communication heat transfer tubes. 2. The multistage heat according to claim 1, wherein the multistage heat exchanger is provided in a heat transfer tube, and the communication heat transfer tube is arranged so that the process fluid naturally flows from the most upstream heat transfer tube to the most downstream heat transfer tube. Exchanger. A heat transfer tube seal gasket that individually surrounds each of the plurality of heat transfer tubes and an outer peripheral seal gasket that collectively surrounds the entire communication heat transfer tube are disposed between the tube plate and the lid plate. ,
An injection part for injecting various fluids into a gap formed between the heat transfer tube seal gasket and the outer peripheral seal gasket, and a discharge part for discharging various fluids from the gap are provided to prevent external contamination. The multi-tube heat exchanger according to claim 2, wherein the heat exchanger is a multi-tube heat exchanger. The pressure resistance of the sealing by the heat transfer tube seal gasket is larger than the pressure resistance of the sealing by the outer peripheral seal gasket,
The multi-tube heat exchanger according to claim 2 or 3, wherein various fluids injected into the gap are prevented from entering the shell.

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