JP2016166717A - Shell-and-tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shell-and-tube heat exchanger having uniform and high heat exchange efficient, capable of coping with a large amount of exchange heat amount compactly, and used for cleaning of an electronic material or metal material.SOLUTION: Respective tube units U1, U2 vertically arranged in a shell 1 are formed into such a doughnut shape that a plurality of heat exchange tubes 2 is respectively wound in a lateral vortex manner and arranged in a vertical multistage manner. An inlet header 3A and an outlet header 3B for first fluid L1 are connected to a header 3C for connection. By feeding first fluid L1, inflowing from the inlet header 3A, from a lower tube unit U2 to an upper tube unit U2 through the header 3C for connection and leading out it to the outlet header 3B, the first fluid is subjected to heat exchange with second fluid L2 circulating through a space in the shell 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shell-and-tube type heat exchanger in which a plurality of heat exchange tubes are arranged in a shell, particularly the same heat exchange useful for cooling and heat recovery of high temperature waste liquid used for cleaning electronic materials and metal materials. Related to the vessel.

  In general, as means for cleaning the surface of various electronic materials including a semiconductor substrate, a hydrogen peroxide solution-sulfuric acid mixture (SPM), a hydrogen peroxide-hydrochloric acid mixture (HPM), a hydrogen peroxide- A so-called RCA cleaning method in which high temperature cleaning is performed using an ammonia water mixed solution (APM) or the like is widely used. A high-temperature strong acid solution is also used for removing the scale of the surface of the metal material. These high-temperature waste liquids after use are usually cooled by heat exchange with a low-temperature fluid for recycling and after-treatment, and the recovered heat by the heat exchange is usually effectively used.

  As a heat exchanger used for cooling such a high temperature waste liquid, a large shell and tube type heat exchanger in which a plurality of heat exchange tubes are arranged in a shell because a large amount of treatment liquid is generally required and a large amount of heat is required for exchange. Is frequently used. This shell-and-tube heat exchanger has various forms with different shapes and arrangements of the heat exchange tubes. Among them, a coil in which a plurality of helical coil heat exchange tubes having different winding diameters are arranged concentrically. In addition to a large heat transfer area, the type heat exchanger has an advantage that the amount of exchange heat can be increased by lengthening the flow path of each tube (for example, Patent Documents 1 to 3).

JP-A-7-181291 JP-A-8-54192 JP 2009-127971 A

  However, in the coil heat exchanger, when each heat exchange tube has the same number of coil turns, the tube length becomes longer on the outer peripheral side, so the difference in heat transfer area between the inner peripheral side and the outer peripheral side is large. There is a problem that heat exchange becomes uneven. In addition, when the number of coil turns is increased on the inner peripheral side and the length of each heat exchange tube is made equal (Patent Document 2), a difference in tube arrangement density occurs between the inner peripheral side and the outer peripheral side. It is inevitable that the heat exchange is uneven. On the other hand, in the coil heat exchanger, the heat exchange amount can be increased by lengthening the flow path of each heat exchange tube and increasing the number of tubes. However, since the shell increases in size, the installation space and manufacturing cost are reduced. There are large restrictions.

  In view of the above circumstances, the present invention provides a uniform and high heat exchange efficiency as a shell-and-tube heat exchanger, and is compact and can handle a large amount of exchange heat, for example, used for cleaning electronic materials and metal materials. It aims at providing a useful thing for cooling of the high temperature waste liquid and heat recovery.

  If the means for achieving the above object is shown with reference numerals in the drawings, the shell-and-tube heat exchanger according to the invention of claim 1 includes a plurality of tube units (first and second) in the shell 1. In the embodiment, U1, U2 and U1 to U3 in the third embodiment are loaded in an up-and-down arrangement, and each tube unit is arranged in a plurality of upper and lower stages by winding a plurality of heat exchange tubes 2 in a horizontal spiral shape. It has a donut shape, and the shell 1 is connected for connection between the inlet header 3A and outlet header 3B of the first fluid L1 circulated in the tube 2 of the tube unit, and the in-tube flow path between adjacent tube units. The header 3C is attached, and the heat exchange tubes (extending end portions 2a and 2b) extending from the tube units pass through the doughnut-shaped central space 20 and the inlet header 3A. The supply port (supply / discharge port 5A) of the second fluid L2 that is connected to one of the outlet header 3B and the connection header 3C and circulates in the inner space of the shell is connected to the same discharge port (supply / discharge) on the upper and lower sides of the shell 1. 5B) are provided on the other upper and lower sides of the shell 1, respectively, and the first fluid L1 flowing in from the inlet header 3A is sequentially supplied from the lowest or highest tube unit to the next tube through the connection header 3C. By being sent to the unit and led out to the outlet header 3B, heat is exchanged with the second fluid L2 flowing in the inner space of the shell.

  The invention of claim 2 is the shell-and-tube heat exchanger of claim 1, wherein the first fluid L1 is a liquid, and the liquid is transferred from the lowest tube unit to the higher order via the connection header 3C. It is configured to feed into the tube unit.

  According to a third aspect of the present invention, in the shell and tube heat exchanger according to the first or second aspect, the tube unit is vertically adjacent to each other and between the uppermost tube unit and the lowermost tube unit. The plate-like baffles 6 </ b> A to 6 </ b> C are arranged to give a change in the shell radial direction to the vertical flow of the second fluid L <b> 2.

  According to a fourth aspect of the present invention, in the shell and tube heat exchanger according to any one of the first to third aspects, the two heat exchange tubes in each tube unit are arranged in a staggered arrangement in the longitudinal section.

  A fifth aspect of the present invention is the shell and tube heat exchanger according to any one of the first to fourth aspects, wherein the first fluid L1 is sequentially connected from the tube unit closer to the discharge port (supply / discharge port 5B). The entire flow of the first fluid L1 and the second fluid L2 in the shell 1 is set upside down by being sent to the next tube unit via the header 3C and led to the outlet header 3B. It is configured.

  The invention of claim 6 is the shell-and-tube heat exchanger according to any one of claims 1 to 5, wherein each heat exchange tube 2 is made of a fluororesin, and the shell 1 and each header 3A, 3B, 3C are corrosion resistant. The inner surface of the shell 1 is arranged on the surface of the shell 1 (seal plates 4A and 4B, baffles 6A to 6C, tube supports 7A and 7B) made of fluororesin, or the surface is coated with a corrosion-resistant lining or coating. It is the composition which consists of what was done.

  According to a seventh aspect of the present invention, in the shell and tube heat exchanger of the sixth aspect, one of the first fluid L1 and the second fluid L2 is a high-temperature corrosive liquid and the other is a low-temperature liquid.

  Next, effects of the present invention will be described with reference numerals in the drawings. In the shell-and-tube heat exchanger according to the invention of claim 1, a plurality of tube units (U1, U2 in the first and second embodiments, U1-U3 in the third embodiment) are vertically arranged in the shell 1. The first fluid L1 that is loaded and flows in from the inlet header 3A is sequentially sent from the lowermost or uppermost tube unit arranged vertically to the next tube unit via the connection header 3C and led to the outlet header 3B. Thus, heat is exchanged with the second fluid L2 that flows from the supply port (supply / discharge port 5A) into the space in the shell and moves toward the discharge port (supply / discharge port 5B). In this heat exchange, each tube unit arranged vertically forms a donut shape in which a plurality of heat exchange tubes 2 are wound in a horizontal spiral shape and arranged in a plurality of upper and lower stages, so that the tube density in the heat exchange region is increased. In addition to ensuring a large heat transfer area, the heat exchange tubes 2 can be set to approximately the same length and the arrangement density of the heat exchange tubes 2 can be set evenly in the entire heat exchange region. The heat transfer area can be made uniform and highly efficient. In addition, since the flow paths in the tubes of the plurality of tube units communicate with each other via the connection header 3C, the entire first fluid L1 is compared with the case where the first fluid L1 is individually introduced for each tube unit. If the supply amount is the same, the flow velocity in the tube will be several times the unit (2 times for 2 units, 3 times for 3 units), so the inner film heat conduction coefficient will be increased by increasing the number of Ray nozzles proportional to the flow rate. As a result, the overall heat transfer coefficient increases and the heat exchange efficiency increases. In particular, if the first fluid L1 is a liquid, it is easy to increase the flow velocity in the tube to make the flow turbulent (the number of Ray nozzles Re> 4000), thereby dramatically increasing the heat exchange efficiency. Is possible.

  On the other hand, this shell-and-tube heat exchanger has a header for connection with the inlet header 3A and the outlet header 3B through the doughnut-shaped central space 20 through the heat exchange tubes (extension ends 2a, 2b) extending from the respective tube units. Since it is connected to any one of 3C, there is an advantage that it can be configured compactly with high space efficiency, although there is little surplus space in the shell 1 and a large amount of exchange heat is obtained. Furthermore, the heat exchange tube 2 is independent for each tube unit, and the tube length is markedly greater than when the flow path from the inlet header 3A to the outlet header 3B is formed by a single continuous tube. When the heat exchanger is assembled and manufactured, it is very easy to wind it in a horizontal spiral shape and arrange it in a plurality of upper and lower stages, and there is an advantage that the labor and time of the work are remarkably reduced.

  According to the invention of claim 2, since the first fluid L1 which is a liquid is sequentially fed from the lowest tube unit to the upper tube unit via the connection header 3C, the liquid flow from the lower side to the upper side is favorable. The air can be discharged quickly from the heat exchange tube 2 at the start of use, and the bubbles accompanying or generated in the first fluid L1 can be quickly removed from the tube. A decrease in exchange efficiency can be suppressed.

  According to the invention of claim 3, the upper and lower sides of the second fluid L2 are caused by the baffles 6A to 6C interposed between the upper and lower adjacent tube units and between the upper side of the uppermost tube unit and the lower side of the lowermost tube unit. Since a change in the shell radial direction is given to the flow in the direction, the temperature distribution in the shell radial direction of the second fluid L2 during the heat exchange is flattened, and a more uniform and high heat exchange efficiency is obtained.

  According to invention of Claim 4, 2 groups of heat exchange tubes of each tube unit are a staggered arrangement | sequence, and can increase a tube density significantly compared with a square arrangement | sequence, and, therefore, the same heat-transfer area as a square arrangement | sequence. Then, the tube unit can be made more compact, and there is an advantage that the outer film heat transfer coefficient of the heat exchange tube 2 is improved and the heat exchange efficiency is increased.

  According to the invention of claim 5, in addition to the fact that the overall flow of the first fluid L1 and the second fluid L2 in the shell 1 is a heat exchange of a shape close to countercurrent in the upside down direction, When L1 moves from the previous tube unit to the next tube unit, the first fluid L1 having a different liquid temperature flowing out from the heat exchange tube 2 group of the previous tube unit merges at the connection header 3C, and the liquid temperature is average. In this state, it is distributed to the heat exchange tubes 2 group of the next tube unit, and the next tube unit exchanges heat with a large average temperature difference with respect to the second fluid. A large amount of exchange heat can be obtained.

  According to the invention of claim 6, each heat exchange tube 2 is made of a fluororesin, the shell 1 and each header 3 </ b> A, 3 </ b> B, 3 </ b> C have a corrosion-resistant inner surface, and each placement member (seal in the shell 1 is sealed) Since the plates 4A and 4B, the baffles 6A to 6C, and the tube supports 7A and 7B) are made of a fluororesin or have a surface coated with a corrosion-resistant coating or lining, the first fluid L1 and the second fluid L2 One or both of them can be applied without any trouble even if they are highly corrosive liquids such as strongly acidic liquids and strong alkaline liquids. In addition, since the heat exchange tube 2 made of fluororesin is flexible and easily bends, when assembling and manufacturing the tube unit, it is very difficult to wind the plurality of tubes in a horizontal spiral and arrange them in multiple upper and lower stages. The workability is much higher than that of metal tubes.

  According to the seventh aspect of the present invention, since the contact surfaces of the first fluid L1 and the second fluid L2 are all highly corrosion resistant, one of the fluids L1 and L2 can be used as a hot corrosive liquid and the other as a low temperature liquid without any problem. Heat exchange can be performed.

It is a half vertical front view of the shell and tube type heat exchanger of a first embodiment concerning the present invention. It is a top view of the same heat exchanger. It is a top view of the tube unit part of the same heat exchanger. It is a model longitudinal cross-sectional view which shows the arrangement | positioning form of the heat exchange tube in the same heat exchanger. It is a top view of the seal plate arrange | positioned at the entrance / exit header of the same heat exchanger. It is a top view of the seal plate arrange | positioned at the header for a connection of the same heat exchanger. 2 shows a continuous two-stage horizontal spiral shape of the heat exchange tube, wherein (a) is a schematic diagram of the lower stage side and (b) is a schematic diagram of the upper stage side. The baffle used for the said heat exchanger is shown, (a) is an upper stage baffle, (b) is a middle stage baffle, (c) is a top view of each half part of a lower stage baffle. The parallel flow type heat exchange by the shell and tube type heat exchanger of 1st embodiment is shown, (a) is a fluid pathway diagram, (B) is an operation diagram. The counter-flow type heat exchange by the shell and tube type heat exchanger of 2nd embodiment is shown, (a) is a fluid pathway diagram, (B) is an operation diagram. 3 shows counter-current heat exchange by the shell-and-tube heat exchanger of the third embodiment, where (a) is a fluid path diagram and (B) is an operation diagram.

  Hereinafter, embodiments of a shell and tube heat exchanger according to the present invention will be specifically described with reference to the drawings.

  As shown in FIG. 1, the shell-and-tube heat exchanger of the first embodiment includes two upper and lower tube units U1, U2 supported by tube supports 7A, 7B in a substantially vertical cylindrical shell 1, respectively. Is loaded. The shell 1 includes a shell body 11 that opens upward, and a lid plate 12 that is bolted to a flange portion 11a at the periphery of the opening via a gasket 13 and sealed. The bottom surface of the shell body 11 bulges downward is provided with a first fluid inlet header 3A located at the center and a second fluid inlet / outlet 5A at an eccentric position. As shown in FIG. 2, the cover plate 12 includes an inlet header 3B and a connection header 3C for the first fluid, a supply / exhaust port 5B for the second fluid, and a nozzle 14 for venting and safety valve. It is provided in a cross coordination. Reference numeral 15 denotes a hanging metal fitting provided equally at the upper end portion of the shell main body 11 and four places around the lid plate 12, and 16 denotes a support leg.

  As shown in FIG. 4, the tube units U1 and U2 have a plurality (eight in the figure) of heat exchange made of a heat-melting fluororesin such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer). The tube 2 is wound in a horizontal spiral shape and has a donut shape in which the tube 2 is arranged in a plurality of upper and lower stages (in the figure, two stages with a total of 16 stages). Each of the heat exchange tubes 2 of the upper tube unit U1 has an extended end 2a on the introduction side connected to the connection header 3C through the central space 20 having a donut shape, and an extended end 2b on the outlet side. Connected to the outlet header 3B. Similarly, each heat exchange tube 2 of the lower tube unit U2 has an extended end 2a on the introduction side connected to the inlet header 3A through the central space 20 having a donut shape, and an extended end on the outlet side. 2b is connected to the connection header 3C.

  As shown in FIGS. 3 and 4, the upper tube support 7 </ b> A includes four tube holding plates 71 along the radial direction that are cross-coordinated apart from the center of the shell, and these tube holding plates 71 are arranged in the upper and lower parts. The inner and outer support rings 72 and 73 are supported through the heat shrink ring 73. The lower tube support 7B is composed of four similar tube holding plates 71 and two inner and outer support rings 72 and 73 that respectively penetrate and support these tube holding plates 71 in the lower part. Yes. Then, an upper end portion of each tube holding plate 71 in the upper tube support body 7A and a lower end portion of each tube holding plate 71 in the lower tube support body 7B are provided with a notch opening portion 71b for liquid circulation (FIG. 1). Reference) is provided.

  Further, baffles 6A to 6B having a substantially donut plate shape are interposed between the upper side of the upper tube support 7A, the upper and lower tube supports 7A and 7B, and the lower side of the upper tube support 7A. . The upper baffle 6A, as shown in FIG. 8 (a), has a central hole 61 that is long in the radial direction, and an outer space so as to form a gap g with the shell inner peripheral surface 1a indicated by a two-dot chain line. The diameter is set small. The intermediate baffle 6B has a large-diameter central hole 62 as shown in FIG. 8B, and has a large outer diameter so that the outer periphery is in contact with the shell inner peripheral surface as shown in FIG. As shown in FIG. 8C, the lower baffle 6C has a small-diameter central hole 63 and, like the upper baffle 6A, the outer baffle 6C is formed so as to form a gap g with the shell inner peripheral surface 1a. The diameter is set small. In addition, as shown in FIG. 3, the size of the central holes 61 to 63 of these baffles 6A to 6B is such that the long diameter of the central hole 61> the diameter of the central hole 62> the short diameter of the central hole 61> the diameter of the central hole 63, It has become. Further, the upper and lower baffles 6A and 6C are held in such a manner as to be fitted into the notches on the inner peripheral side of the tube holding plates 71 of the tube supports 7A and 7B, respectively.

  The heat exchange tubes 2 of the tube units U1 and U2 are mutually wound in a state of being wound in a horizontal spiral shape by being inserted into the insertion holes 71a formed in the tube holding plates 71 of the tube supports 7A and 7B. The interval is kept constant. Moreover, as shown in FIG.1 and FIG.4, the arrangement | sequence of the horizontal spiral of the heat exchange tube 2 in both tube units U1 and U2 has shifted | deviated by a half pitch to the shell radial direction alternately by the adjacent upper and lower stage, and, as a whole. It is set to be a staggered arrangement. In addition, each heat exchange tube 2 in this first embodiment is as shown in FIG. 7 (a), starting from the extended end portion 2a on the inner peripheral side (the donut-shaped central space 20 side), and starting from the inside. Winding outward in a lateral spiral shape, and then moving upward from the outermost periphery to the next upper stage, sequentially winding inward in a lateral spiral shape as shown in FIG. 7 (b), and extending from the innermost periphery to the outlet side. By pulling out the extended end 2a, or by starting the extended end 2a on the outlet side as a starting point and reciprocally winding inward and outward in the reverse procedure, and pulling out the extended end 2b on the introduction side from the innermost periphery One piece constitutes a two-stage horizontal spiral.

  In the inlet header 3A, the outlet header 3B, and the connection header 3C, as shown in FIGS. 1 and 4, a disc-shaped seal plate 4A, between the base side flange 31 and the cap side flange 32, which are bolted to each other, 4B is sandwiched, and a header space 30 is formed outside the seal plates 4A and 4B. As shown in FIGS. 5 and 6, the sealing plates 4 </ b> A and 4 </ b> B are provided with tube fixing holes 40 corresponding to the number of heat exchange tubes 2 to be connected. The extended end portions 2a and 2b of each heat exchange tube 2 are welded (fused and fixed) through the tip side. The number of tube fastening holes 40 is 8 in the seal plate 4A of the inlet header 3A and the outlet header 3B, but 16 in the seal plate 4B of the connection header 3C, and the diameter line d shown in FIG. As a boundary, eight on one side half correspond to the extended end 2b on the outlet side of each heat exchange tube 2 in the lower tube unit U1, and eight on the other side half correspond to each in the upper tube unit U2. It corresponds to the extended end 2a on the introduction side of the heat exchange tube 2. In addition, an inner and outer double annular protrusion 41 is formed on the periphery of both surfaces of the seal plates 4A and 4B in order to improve the sealing performance.

  Here, the shell main body 11 and the cover plate 12 are made of stainless steel such as SUS304, and the inner surface thereof is subjected to an acid resistant coating. Each header 3A, 3B, 3C is provided with a lining made of a fluorine resin such as PTFE (polytetrafluoroethylene) on the inner surface side of a base material made of stainless steel. The seal plates 4A and 4B are made of a fluororesin molded product such as PTFE. On the other hand, in the tube supports 7A and 7B, the tube holding plates 71 and the baffles 6A to 6C are made of fluorine resin such as PTFE, and the inner and outer support rings 72 and 73 are made of fluorine resin on the surface of a stainless steel pipe. It consists of a material with a corrosion resistant coating.

  In the shell and tube heat exchanger configured as described above, the first fluid L1 is introduced from the inlet header 3A, and the second fluid L2 having a large temperature difference with respect to the first fluid L1 is supplied to the supply / discharge ports 5A and 5B. By supplying from one side, heat exchange is performed between the fluids L1 and L2. Thus, the first fluid L1 introduced from the inlet header 3A is distributed to a plurality (e.g., eight) of heat exchange tubes 2 and sent to the lower tube unit U2, and each heat exchange tube 2 is After wrapping around from the inside to the outside in a horizontal spiral shape, and then wrapping around from the outside to the inside in a horizontal spiral shape, it is sent to the connecting header 3C through the extended end 2b on the lead-out side, and in the header space 30 Join at. Next, in a state in which the temperature is averaged by this merging, the heat flows into the plurality of heat exchange tubes 2 (eight in the example) of the upper tube unit U2 and flows into the heat exchange tubes 2 from the inside in the same manner. After reciprocating in a lateral spiral shape from the outside to the outside and then from the outside to the inside, the sheet is led out from the outlet header 3C through the extended end 2b on the lead-out side.

  The second fluid L2 is supplied into the shell 1 with one of the upper and lower supply / discharge ports 5A and 5B serving as a supply port and the other serving as a discharge port. If the second fluid L2 is supplied from the lower supply / discharge port 5A, the flow is parallel to the first fluid L1 moving upward in the shell 1 as a whole, and conversely supplied from the upper supply / discharge port 5B. Is counterflowing to the first fluid L1, but in both tube units U1 and U2, the first fluid L1 flows through each of the transverse spiral heat exchange tubes 2, so the first fluid L1 is substantially horizontal. Heat exchange is performed in the form of a cross flow in which the flow and the rising flow of the second fluid intersect.

  In this heat exchange, each of the tube units U1 and U2 arranged above and below forms a donut shape in which a plurality of heat exchange tubes 2 are wound in a horizontal spiral shape and arranged in a plurality of upper and lower stages. In addition to ensuring a large heat transfer area by increasing the tube density, the heat exchange tubes 2 can be set to approximately the same length and the arrangement density of the heat exchange tubes 2 can be set uniformly throughout the heat exchange region. A uniform and highly efficient heat exchange can be performed without causing a difference in heat transfer area between the peripheral side and the outer peripheral side. Moreover, since the flow paths in the tubes of both the tube units U1 and U2 communicate with each other via the connection header 3C, the first fluid L1 is introduced and led out separately for each tube unit. If the total supply amount of one fluid L1 is the same, the flow velocity in the tube is doubled, and as a result of the increase in the number of Ray nozzles Re that is proportional to the flow velocity, the inner film heat conduction coefficient increases, the overall heat transfer coefficient also increases. Heat exchange efficiency. In particular, if the first fluid L1 is a liquid, it is easy to increase the flow velocity in the tube to make the flow turbulent (ray nozzle number Re> 4000), thereby dramatically increasing the heat exchange efficiency.

  In the first embodiment, there is a gap g between the outer peripheral edges of the upper and lower baffles 6A and 6C and the inner peripheral surface 1a of the shell, and the central holes 61 and 63 of both the baffles 6A and 6C are small. Since the extended end portions 2a and 2b of the plurality of heat exchange tubes 2 are passed through to narrow the upper and lower permeable areas, when the second fluid L2 passes through the positions of both the baffles 6A and 6C, The flow to the side increases. On the other hand, the baffle 6B at the intermediate portion has an outer peripheral edge that is in contact with the inner peripheral surface 1a of the shell and a large central hole 62. Therefore, the second fluid L2 passes through the central side at the position of the baffle 6B. Therefore, for example, the second fluid L2 supplied from the lower supply / discharge port 5A first flows in the converging direction from the shell peripheral side to the shell central side in the lower tube unit U2, and then the upper tube unit. In U1, it is the flow which was outstanding in the expansion | deployment direction from the shell center side to the shell peripheral side, and each passes between 2 groups of heat exchange tubes, and reaches the upper supply / discharge port 5B. As described above, the change in the shell radial direction is added to the vertical flow of the second fluid L2, so that the temperature distribution in the shell radial direction of the second fluid L2 during heat exchange is flattened, and more uniform and higher heat exchange is achieved. Efficiency is obtained.

  Furthermore, in this first embodiment, since the first fluid L1 is sent from the lower tube unit U2 to the upper tube unit U1 via the connection header 3C, when the first fluid L1 is a liquid, A good air venting action due to the liquid flow from the bottom to the top can be obtained, the air in the heat exchange tube 2 can be quickly discharged at the start of use, and the bubbles accompanying or generated in the first fluid L1 can be discharged to the outside of the tube. Exclusion becomes quicker, and a decrease in heat exchange efficiency due to bubbles can be suppressed. When the second fluid L2 is a liquid, if the second fluid L2 is supplied from the lower supply / exhaust port 5A as a parallel flow system, an air bleeding action of the inner space of the shell by the rising liquid flow is obtained, Since air bubbles between the heat exchange tubes 2 of both tube units U1 and U2 can be easily removed, it is possible to further suppress a decrease in heat exchange efficiency due to the air bubbles.

  In addition, this shell-and-tube heat exchanger includes an inlet header 3A and an outlet header 3B through the extended end portions 2a, 2b of the heat exchange tube 2 extending from the tube units U1, U2 through the donut-shaped central space 20. Since it is connected to the connection header 3C, there is an advantage that it can be configured compactly with high space efficiency, although there is little surplus space in the shell 1 and a large amount of exchange heat can be obtained. Furthermore, the heat exchange tube 2 is independent in each of the tube units U1 and U2, and the tube length is longer than when the flow path from the inlet header 3A to the outlet header 3B is formed by a single continuous tube. Therefore, when assembling and manufacturing a heat exchanger, it is very easy to wind it in a horizontal spiral and arrange it in a plurality of upper and lower stages, and the labor and time of the work are remarkably reduced. There are also advantages.

  Moreover, in this first embodiment, since the two heat exchange tubes of each of the tube units U1 and U2 are in a staggered arrangement, the tube density can be significantly increased compared to the square arrangement, and thus the square arrangement. In the same heat transfer area, the tube units U1 and U2 can be made more compact, and the outer boundary film heat transfer coefficient of the heat exchange tube 2 can be improved to increase the heat exchange efficiency.

  In the first embodiment, two upper and lower tube units U1 and U2 are arranged in the shell 1, but the shell-and-tube heat exchanger of the present invention has three or more similar tube units arranged in the upper and lower sides in the shell 1. The configuration loaded with may be used. As described above, in the heat exchanger including three or more tube units, the heat exchange tube 2 of the uppermost tube unit is connected to one of the inlet header 3A and the outlet header 3B, and the heat exchange of the lowermost tube unit is connected to the other. The tube 2 may be connected to the other and the heat exchange tubes 2 between the upper and lower adjacent tube units may be connected to each other via the connection header 3C. And also in the heat exchanger provided with three or more tube units, the extension ends 2a and 2b of each heat exchange tube 2 in each tube unit are connected to the headers 3A to 3D through the donut-shaped central space 20 of these tube units. What is necessary is just to connect to 3C. Note that the inlet header, the outlet header, and the connection header may be provided on either the upper side or the lower side of the shell 1.

  Further, in the first embodiment, the baffles 6a to 6C are interposed in the upper and lower parts and the middle part, but even in the heat exchanger having three or more tube units, the upper and lower tube units are adjacent to each other. A baffle is interposed between the upper side of the lowermost tube unit and the lower side of the lowermost tube unit, and the shell radial direction is changed in the vertical flow of the second fluid by the difference in the inner and outer diameters and / or the central hole shape. May be.

  On the other hand, the first fluid L1 introduced from the inlet header 3A is sequentially connected to the connection header 3C from the tube unit (the tube unit U1 in the first embodiment) closer to the discharge port (the supply / discharge port 5B in the first embodiment). If the overall flow of the first fluid L1 and the second fluid L2 in the shell 1 is set so as to be upside down by sending it to the next tube unit through the outlet header 3B, In addition to heat exchange in a form in which both fluids L1 and L2 are close to countercurrent, when the first fluid L1 moves from the previous tube unit to the next tube unit, the heat exchange tubes 2 group of the previous tube unit The first fluids L1 with different liquid temperatures flowing out from the pipes merge at the connection header 3C, and are distributed to the heat exchange tubes 2 group of the next tube unit in a state where the liquid temperatures are averaged. In Yubuyunitto since the heat exchange in the state the average temperature difference is larger than the second fluid, there is an advantage that a very large amount of heat exchange in a special operating line is obtained.

  The shell-and-tube heat exchanger of the present invention can be applied to any liquid-liquid, gas-liquid, and gas-gas heat exchange, but is particularly suitable for liquid-liquid heat exchange. Then, as exemplified in the first embodiment, the heat exchange tube 2 made of fluororesin is used, and the shell 1 and the inner surfaces of the headers 3A, 3B, 3C are coated with a corrosion-resistant coating or lining, and the shell 1 If each of the arrangement members is made of a fluororesin or has a surface coated with a corrosion-resistant coating or lining, one or both of the first fluid L1 and the second fluid L2 is a strong acidic liquid or a strong alkaline liquid. Even such highly corrosive liquids can be applied without any problem. For example, heat exchange can be performed without hindrance by using one of the fluids L1 and L2 as a high-temperature corrosive liquid and the other as cooling water or a low-temperature corrosive liquid. In addition, since the heat exchange tube 2 made of fluororesin is flexible and easily bends, when assembling and manufacturing the tube unit, it is very difficult to wind the plurality of tubes in a horizontal spiral and arrange them in multiple upper and lower stages. There is also an advantage that workability is much higher than that of a metal tube.

  The number of heat exchange tubes 2 in each tube unit, the number of horizontal spiral turns of each heat exchange tube 2, and the number of horizontal spiral upper and lower stages can be variously set according to the exchange heat quantity and size of the heat exchanger. For example, in each of the tube units U1 and U2 of the first embodiment, each of the eight heat exchange tubes 2 is set in two upper and lower stages by eight windings, but the horizontal spiral of each heat exchange tube 2 is 1 In a large heat exchanger having a large number of stages or three stages, or a large amount of heat exchanged, the horizontal spirals of several heat exchange tubes 2 may be arranged inside and outside to form one stage of horizontal spirals.

[Heat exchange treatment example 1]
The following specifications as the shell and tube type heat exchanger of the first embodiment described above;
Shell 1: Inner volume 265L, inner diameter 594mm, inner height 950mm.
Tube units U1, U2: Total heat transfer area of about 13 m ² , total tube inner volume of about 31 L, central space diameter of 250 mm (reference to inner end of tube holding plate 71).
Heat exchange tube 2: For each tube unit, 8 PFA tubes with an outer diameter of 12 mm, an inner diameter of 10 mm, and a length of about 25 m, each of which is 8 windings in a horizontal spiral shape with a total of 16 stages.
Baffle 3A: outer diameter 450mm, central hole major axis 290mm, minor axis 150mm.
Baffle 3B: outer diameter 594 mm, central hole diameter 250 mm.
Baffle 3C: outer diameter 450 mm, central hole diameter 120 mm.
In addition, 98% sulfuric acid at a temperature of 120 ° C. is introduced as a first fluid L1 from the inlet header 3A at a pressure of 0.19 MPa or less, and 20 ° C. cooling water is supplied as a second fluid L2 from the lower supply / discharge port 5A. Was supplied at a pressure of 0.3 MPa or less, and the heat exchange process was performed. As a result, the first fluid L1 led out from the outlet header 3B was cooled to 35 ° C., and the second fluid L2 discharged from the upper supply / discharge port 5B was 33 It became hot water heated up to ° C. The fluid path diagram in this heat exchange is shown in FIG. 9A, and the operation diagram is shown in FIG. 9B.

[Example 2 of heat exchange treatment]
As shown in the fluid path diagram of FIG. 10 (a), using the shell and tube heat exchanger of the second embodiment in which only the upper and lower arrangements of the inlet header and the outlet header are reversed with respect to the first embodiment of the above specification. Then, 98% sulfuric acid at a temperature of 120 ° C. is introduced at a pressure of 0.19 MPa or less as the first fluid L1 from the inlet header on the upper side of the shell, and the upper tube unit U1 → connecting header → lower tube unit U2 → outlet header When passing through the path and performing heat exchange treatment by supplying cooling water at 20 ° C. as the second fluid L2 from the lower supply / discharge port into the shell 1 at a pressure of 0.3 MPa or less, an outlet on the lower side of the shell The first fluid L1 derived from the header was cooled to 28 ° C., and the second fluid L2 discharged from the upper supply / discharge port was warm water heated to 34 ° C. In this case, both the fluids L1 and L2 are locally cross-flow heat exchange in the tube units U1 and U2, but in addition to the counter-current heat exchange as a whole, in FIG. As shown in the figure, since the operation line becomes special, higher heat exchange efficiency than that of the heat exchange treatment example 1 is obtained, and the outlet temperatures of the first fluid L1 (98% sulfuric acid) and the second fluid L2 (cooling water) are 6 The result is reversed with a temperature difference of ℃.

[Example 3 of heat exchange treatment]
As the shell and tube type heat exchanger according to the third embodiment, as shown in FIG. 11A, a shell 1 in which three tube units U1 to U3 are loaded in an up-and-down arrangement is used. In this heat exchanger, an inlet header and an outlet header, a connection header between the tube units U1 and U2 and between U2 and U3, and a supply port for the second fluid L2 are provided on the cover plate of the shell 1, while the bottom surface of the shell 1 is provided. A discharge port for the second fluid L2 is provided on the side. As in the first embodiment, the tube units U1 to U3 have a donut shape supported in a wound state via six tube holding plates in which a large number of heat exchange tubes are equally distributed in the circumferential direction. The extending end portions on the introduction side and the outlet side of each heat exchange tube are connected to each header through the donut-shaped central space. The whole of these three tube units U1 to U3 is a tube support body composed of upper and lower support rings interposed between the upper and lower units and six support columns that connect the support rings at the positions of the respective tube holding plates. It is supported by one. Further, baffles are arranged at four locations on the upper side of the tube unit U1, between the U1 and U2, between the U2 and U3, and below the U3. The heat exchanger specifications are as follows.
Shell 1: Internal volume of about 1,000L, inner diameter of 1,000mm, shell body height of about 1,100mm.
Tube units U1 to U3: total heat transfer area of about 39 m ² , total tube internal volume of about 70 L.
Heat exchange tubes: Each tube unit has 11 PFA tubes with an outer diameter of 12 mm, an inner diameter of 10 mm, and a length of about 32 m.
First and third stage baffles: outer diameter 980 mm, central hole diameter 300 mm.
Second stage baffle: outer diameter 780 mm, central hole diameter 180 mm.
4th stage baffle; outer diameter 780mm, central hole diameter 10mm.

  In the shell and tube heat exchanger configured as described above, a low-temperature acidic solution at 20 ° C. is introduced from the inlet header as the first fluid L1 at a flow rate of 1,667 kg / h, and the lower tube unit U3 → connecting header → intermediate tube The unit U2 → the connection header → the upper tube unit U1 → the outlet header is passed through, and the high-temperature acidic waste liquid having a temperature of 101 ° C. is supplied at a flow rate of 1,667 kg / h as the second fluid L2 from the supply port on the upper side of the shell. When the heat exchange process is performed by the flow method, the first fluid L1 derived from the outlet header is heated to 70 ° C., and the second fluid L2 discharged from the outlet below the shell is cooled to 51 ° C., The exchange heat quantity was 83,350 kca / h (calculated value). The fluid path diagram in this heat exchange is shown in FIG. 11A, and the operation diagram is shown in FIG. 11B. In this case, the fluids L1 and L2 are locally cross-flow heat exchange in the tube units U1 to U3, but in addition to heat exchange in a form close to countercurrent as a whole, heat exchange processing examples Like FIG. 2, since it becomes the special operation line shown in FIG.11 (b), the big heat exchange amount is obtained with very high heat exchange efficiency.

DESCRIPTION OF SYMBOLS 1 Shell 2 Heat exchange tube 2a, 2b Extension end part 20 Central space 3A Inlet header 3B Outlet header 3C Connection header 5A Supply / exhaust port (supply port)
5B Supply / discharge port (discharge port)
6A-6C Baffle 61-63 Center hole 7A, 7B Tube support L1 First fluid L2 Second fluid U1-U3 Tube unit

In the inlet header 3A, the outlet header 3B, and the connection header 3C, as shown in FIGS. 1 and 4, a disc-shaped seal plate 4A, between the base side flange 31 and the cap side flange 32, which are bolted to each other, 4B is sandwiched, and a header space 30 is formed outside the seal plates 4A and 4B. As shown in FIGS. 5 and 6, the sealing plates 4 </ b> A and 4 </ b> B are provided with tube fixing holes 40 corresponding to the number of heat exchange tubes 2 to be connected. The extended end portions 2a and 2b of each heat exchange tube 2 are welded (fused and fixed) through the tip side. The number of tube fastening holes 40 is 8 in the seal plate 4A of the inlet header 3A and the outlet header 3B, but 16 in the seal plate 4B of the connection header 3C, and the diameter line d shown in FIG. As a boundary, eight on one side half correspond to the extended end 2b on the outlet side of each heat exchange tube 2 in the lower tube unit U2 , and eight on the other side half correspond to each in the upper tube unit U1 . It corresponds to the extended end 2a on the introduction side of the heat exchange tube 2. In addition, an inner and outer double annular protrusion 41 is formed on the periphery of both surfaces of the seal plates 4A and 4B in order to improve the sealing performance.

In the shell and tube heat exchanger configured as described above, the first fluid L1 is introduced from the inlet header 3A, and the second fluid L2 having a large temperature difference with respect to the first fluid L1 is supplied to the supply / discharge ports 5A and 5B. By supplying from one side, heat exchange is performed between the fluids L1 and L2. Thus, the first fluid L1 introduced from the inlet header 3A is distributed to a plurality (e.g., eight) of heat exchange tubes 2 and sent to the lower tube unit U2, and each heat exchange tube 2 is After wrapping around from the inside to the outside in a horizontal spiral shape, and then wrapping around from the outside to the inside in a horizontal spiral shape, it is sent to the connecting header 3C through the extended end 2b on the lead-out side, and in the header space 30 Join at. Next, in a state in which the temperature is averaged by this merging, the heat flows into the plurality of heat exchange tubes 2 (eight in the example) of the upper tube unit U1 and is similarly distributed from the inside to each heat exchange tube 2. After reciprocating in a lateral spiral shape from the outside to the outside and then from the outside to the inside, the sheet is led out from the outlet header 3C through the extended end 2b on the lead-out side.

The invention of claim 5 is the shell-and-tube heat exchanger according to any one of claims 1 to 4 , wherein each heat exchange tube 2 is made of a fluororesin, and the shell 1 and each header 3A, 3B, 3C are corrosion resistant. The inner surface of the shell 1 is arranged on the surface of the shell 1 (seal plates 4A and 4B, baffles 6A to 6C, tube supports 7A and 7B) made of fluororesin, or the surface is coated with a corrosion-resistant lining or coating. It is the composition which consists of what was done.

According to a sixth aspect of the invention, the shell and tube heat exchanger of the fifth aspect, corrosive liquids one is a hot first fluid L1 and the second fluid L2, the other is configured as a cryogenic liquid.

According to the invention of claim 5 , each heat exchange tube 2 is made of a fluororesin, the shell 1 and each header 3 </ b> A, 3 </ b> B, 3 </ b> C have a corrosion-resistant inner surface, and each arrangement member (seal in the shell 1) Since the plates 4A and 4B, the baffles 6A to 6C, and the tube supports 7A and 7B) are made of a fluororesin or have a surface coated with a corrosion-resistant coating or lining, the first fluid L1 and the second fluid L2 One or both of them can be applied without any trouble even if they are highly corrosive liquids such as strongly acidic liquids and strong alkaline liquids. In addition, since the heat exchange tube 2 made of fluororesin is flexible and easily bends, when assembling and manufacturing the tube unit, it is very difficult to wind the plurality of tubes in a horizontal spiral and arrange them in multiple upper and lower stages. The workability is much higher than that of metal tubes.

According to the invention of claim 6 , since the contact surfaces of the first fluid L1 and the second fluid L2 are all highly resistant to corrosion, one of the fluids L1, L2 can be used as a hot corrosive liquid and the other as a low temperature liquid without any problem. Heat exchange can be performed.

Claims (7)

A plurality of tube units are loaded in the shell in a vertical arrangement,
Each tube unit has a donut shape in which a plurality of heat exchange tubes are wound in a horizontal spiral shape and arranged in multiple upper and lower stages,
The shell is provided with an inlet header and an outlet header of the first fluid that circulates in the tube of the tube unit, and a connection header that communicates the flow path in the tube between the vertically adjacent tube units.
A heat exchange tube extending from each tube unit is connected to one of the inlet header, the outlet header and the connection header through the donut-shaped central space,
The second fluid supply port that circulates in the space in the shell is provided on one side of the shell, and the discharge port is provided on the other side of the shell.
The first fluid flowing in from the inlet header is sequentially sent from the lowest or highest tube unit to the next tube unit via the connection header and led to the outlet header, so that the first fluid flowing into the inner space of the shell. A shell and tube heat exchanger configured to exchange heat with two fluids.
  The shell-and-tube heat exchanger according to claim 1, wherein the first fluid is a liquid, and the liquid is sequentially sent from the lowest tube unit to the upper tube unit via the connection header. .   A plate-like baffle that changes the vertical direction flow of the second fluid in the shell radial direction is placed between adjacent upper and lower tube units, and above the uppermost tube unit and below the lowermost tube unit. The shell and tube type heat exchanger according to claim 1 or 2, wherein   The shell-and-tube type heat exchanger according to any one of claims 1 to 3, wherein the heat exchange tube group in each tube unit forms a staggered arrangement in a longitudinal section.   The first fluid is sequentially sent from the tube unit near the discharge port to the next tube unit via the connection header and led to the outlet header, so that the first fluid and the second fluid in the shell are The shell-and-tube heat exchanger according to any one of claims 1 to 4, wherein the entire flow is set upside down.   The heat exchange tube is made of fluororesin, the shell and each header have a corrosion-resistant inner surface, and each placement member in the shell is made of fluororesin or the surface is coated with a corrosion-resistant coating or lining The shell and tube type heat exchanger according to any one of claims 1 to 5.   The shell-and-tube heat exchanger according to claim 6, wherein one of the first fluid and the second fluid is a hot corrosive liquid and the other is a low-temperature liquid.

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