JP5308230B2 - Multi-tube heat exchanger - Google Patents

Description

  The present invention relates to a multi-tube heat exchanger having a plurality of heat transfer tubes, and more particularly, by improving the support structure of the heat transfer tubes that expand and contract by thermal expansion, it is possible to effectively prevent gas leakage from the support portion with a simple configuration. It relates to technology that can be prevented.

  Conventionally, as shown in FIG. 1, for example, in a coating line of an automobile factory, a drying furnace D using hot air is used in order to dry and harden a coating film of an object W to be coated at an early stage.

  The drying furnace W is configured, for example, in a tunnel shape in which both ends are sealed with air curtains or doors, and the objects to be coated W are sequentially supplied and taken out there by a conveyor or the like. The drying furnace D is supplied with, for example, hot air whose temperature is raised to about 200 ° C. by the heat exchanger a.

  However, in the drying furnace D, odorous gas is generated in which harmful substances such as organic solvents and paint resins contained in the paint are volatilized. When such odorous gas is released into the atmosphere as it is, there is a problem of causing pollution. Therefore, conventionally, the odor gas (usually about 150 ° C.) discharged from the drying furnace D is removed from the odor or harmful substances by the gas deodorization system S including the heat exchanger b and the deodorization furnace M, for example. To be released.

  That is, the odor gas is preheated to about 300 ° C. or more in advance by the heat exchanger b, and is then fed to the deodorization furnace M. In the deodorizing furnace M, the odor gas is heated to about 800 ° C. Thereby, organic substance is decomposed | disassembled or detoxified from odor gas, and is discharged | emitted as non-odor gas.

  The detoxified high temperature non-odor gas (about 750 ° C. at the outlet temperature) is sent again to the heat exchanger b, where thermal energy for preheating the odor gas is taken out. Further, the non-odor gas passing through the heat exchanger b is further taken out of the heat energy for heating the outside air supplied to the drying furnace D via the heat exchanger a. After these heat exchanges, the non-odorous gases are exhausted to the outside air.

  By the way, a multitubular heat exchanger is frequently used for the heat exchanger b so that odor gas and non-odor gas are not mixed.

  For example, as shown in FIG. 8, the multitubular heat exchanger includes a cylindrical casing h having an inlet f and an outlet g through which a first gas G1 (odor gas in this example) flows in and out, and a second casing h. Gas G2 (non-odorous gas in this example) flows, and a plurality of pipe-like heat transfer tubes r extending in the casing h, and a support provided on one end side of the casing h and supporting one end side of the heat transfer tube r It includes the front and rear tube sheets j and k having holes. Reference symbol e denotes a partition plate that guides the first gas G1 from the inlet f to the outlet g and supports the intermediate portion of the heat transfer tube r. Accordingly, the second gas G2 flowing through the heat transfer tube r is heat-exchanged via the heat transfer tube with the first gas G1 flowing through the space surrounded by the casing h and the front and rear tube plates j and k. Related literature includes the following:

JP-A-9-53894

  By the way, in the multi-tube heat exchanger, there is a difference in elongation between the heat transfer tube r and the casing h due to thermal expansion. Specifically, the heat transfer tube r greatly extends in the axial direction and the radial direction as compared with the casing h. Therefore, in the conventional multi-tube heat exchanger, various attempts have been made to absorb such a difference in elongation and protect the heat exchanger.

  For example, in the case shown in FIG. 9A, each heat transfer tube r is welded and fixed to the front and rear tube sheets j and k, respectively, while expansion joints m are provided at the front and rear of the casing h. . In this embodiment, it is expected that the difference in elongation (radial direction and axial direction) between the heat transfer tube r and the casing h is absorbed by deformation of the expansion joint.

  However, since the welded portion n between the front tube sheet j and the heat transfer tube r is constantly heated to a high temperature by the second gas G2 (high temperature side), there is a problem that the welded portion n is easily damaged by thermal fatigue. . Moreover, since the expansion joint m supports heavy objects, such as the casing h, and since heat resistance and airtightness are required, its rigidity, heat resistance, and airtightness are required. For this reason, the expansion joint m may not exhibit sufficient flexibility or expansion / contraction performance, and has a drawback in that repeated stress due to expansion / contraction concentrates on the joint portion and cracks and the like are likely to occur.

  In order to solve such a problem, as shown in FIG. 9B, for example, the heat transfer tube r is welded and fixed to the front tube sheet j, while it is welded to the rear tube sheet k. There has also been proposed a structure that is slidably supported (the welding position may be reversed). In this embodiment, since the heat transfer tube r can be extended regardless of the casing h, it is not necessary to provide the expansion joint m described above.

  However, in this embodiment, since a gap is formed between the rear tube plate k and the heat transfer tube r, the first gas G1 (odor gas in this example) is the second gas (non-in this example). May be released to the atmosphere together with odor gas) and cause pollution.

  It has also been proposed to provide a packing, a packing presser plate and the like (both not shown) for preventing gas from flowing out from the gap between the heat transfer tube r and the tube plate k. However, even in such an embodiment, as a result of the packing being exposed to a high-temperature gas, it is easy to burn out in a short period of time, and a sufficient effect is not exhibited.

  The present invention has been devised in view of the above problems, and by improving the support structure of the heat transfer tube that expands and contracts due to thermal expansion, it is possible to effectively suppress gas leakage and the like with a simple configuration. It aims to provide a tubular heat exchanger.

  The invention according to claim 1 of the present invention is a cylindrical casing having an inlet and an outlet through which the first gas flows in and out, and a plurality of pipes extending in the casing as the second gas flows. A heat transfer tube, a first tube plate provided on one end side of the casing and supporting one end side of the heat transfer tube, and a first tube plate provided on the other end side of the casing and supporting the other end side of the heat transfer tube. Heat exchange via the heat transfer tubes with the first gas flowing through the space surrounded by the casing, the first tube plate, and the second tube plate. In the multi-tube heat exchanger, the first tube plate and the one end side of each heat transfer tube are fixed, while the other end side of each heat transfer tube is the second tube plate Slidable on the other end side and supported by the second tube sheet, A guide tube that is longer than the protruding portion of the heat transfer tube that protrudes from the tube plate and has an inner diameter that approximates the outer diameter of the protruding portion, and is slidably inserted into the protruding portion. Features.

  According to a second aspect of the present invention, in the multi-tube heat exchange according to the first aspect, the guide tube is abutted against a surface on the other end side of the second tube plate and is welded and fixed to the second tube plate. It is a vessel.

  According to a third aspect of the present invention, in the multi-tube type according to the first aspect, the guide pipe is held by being abutted against a surface on the other end side of the second tube sheet by a support fitting fixed to the casing. It is a heat exchanger.

  According to a fourth aspect of the present invention, the second gas is the first gas from the second tube sheet side at a flow rate that prevents the first gas from leaking from the gap between the heat transfer tube and the induction tube. The multi-tube heat exchanger according to claim 1, wherein the multi-tube heat exchanger is fed to the tube plate side.

  The invention described in claim 5 is a gas deodorizing system including the multi-tube heat exchanger described in claim 4 and a deodorizing furnace for deodorizing by heating odor gas, wherein the first gas Is a odor gas, and the second gas is a non-odor gas having a temperature higher than that of the first gas obtained by passing the first gas through the deodorization path.

  According to a sixth aspect of the present invention, in the first aspect, the guide tube is inserted into a support hole provided in the second tube sheet and welded to the surface on the one end side of the second tube sheet. This is a multi-tube heat exchanger.

  According to a seventh aspect of the present invention, the guide tube is inserted into a support hole provided in the second tube sheet and welded to the surface on the other end side of the second tube sheet. It is a multitubular heat exchanger of description.

  The invention according to claim 8 is that the second gas is formed between the first tube plate and the second tube plate through a gap between the heat transfer tube and the induction tube. The multi-tube heat exchanger according to claim 6 or 7, wherein the multi-tube heat exchanger is fed from the first tube sheet side to the second tube sheet side at a flow rate that prevents leakage.

  The invention described in claim 9 is a gas deodorization system including the multi-tubular heat exchanger according to claim 8 and a deodorization furnace for deodorizing by heating odor gas, wherein the second gas Is a odor gas, and the first gas is a non-odor gas having a higher temperature than the second gas obtained by passing the second gas through the deodorization path.

  According to the multi-tube heat exchanger of the present invention, the first tube plate and the one end side of each heat transfer tube are fixed, while the other end side of each heat transfer tube is slidable on the second tube plate. And it protrudes to the other end side and is supported. In addition, the second tube plate has an inner diameter that is longer than the protruding portion of the heat transfer tube that protrudes from the second tube plate and approximates the outer diameter of the protruding portion, and can slide the protruding portion. A guide tube for interpolating is provided.

  Such a support structure can allow the heat transfer tube to extend regardless of the casing. Therefore, a large internal stress does not act on the heat exchanger due to the extension of the heat transfer tube during heat exchange. Moreover, since the other end side of the heat transfer tube is supported not only by the tube plate but also by the induction tube, it is supported at a long distance in the axial direction. This is useful for lengthening the path of gas leakage and increasing the flow resistance and suppressing gas leakage. Further, due to the thermal expansion of the heat transfer tube, the gap between the induction tube and the heat transfer tube is reduced, and the contact length is increased, so that gas leakage can be further suppressed.

  Further, as in the invention described in claim 2, when the guide tube is butted against the surface on the other end side of the second tube sheet and is welded and fixed to the second tube sheet, from the butted portion Helps to suppress gas leaks.

  In addition, as in the third aspect of the present invention, the guide tube may be held in contact with the surface on the other end side of the second tube sheet by a support fitting fixed to the casing. In this embodiment, welding between the heat transfer tube and the tube sheet is unnecessary, and productivity is improved.

  According to a fourth aspect of the present invention, the second gas has a flow rate that prevents the first gas from leaking from the gap between the heat transfer tube and the induction tube. To the first tube sheet side. That is, by increasing the flow rate of the second gas, it is possible to prevent the first gas from leaking from the gap between the heat transfer tube and the induction tube.

  A gas deodorizing system comprising the multitubular heat exchanger according to claim 4 and a deodorizing furnace for deodorizing the odor gas by heating the odor gas, as in the invention according to claim 5, When the second gas is an odor gas and the second gas is a non-odor gas having a temperature higher than that of the first gas by passing the first gas through the deodorization path, the odor gas is introduced into the induction tube. It is possible to provide a system that can effectively suppress leakage to the side.

  Further, as in the sixth aspect of the present invention, the guide tube may be inserted into a support hole provided in the second tube sheet and welded to the surface on the one end side of the second tube sheet. Alternatively, as in the seventh aspect of the present invention, it may be inserted into a support hole provided in the second tube sheet and welded on the surface on the other end side of the second tube sheet. Thereby, a guide tube and a 2nd tube sheet can be fixed more reliably.

  Further, as in the invention according to claim 8, in the structure of claim 6 or 7, the second gas passing through the heat transfer tube is the first gas from the gap between the heat transfer tube and the induction tube. It is desirable to feed from the first tube sheet side to the second tube sheet side at a flow rate that prevents leakage between the tube sheet and the second tube sheet.

  Further, as in the invention described in claim 9, there is provided a gas deodorizing system including the multi-tube heat exchanger described in claim 8 and a deodorizing furnace that deodorizes the odor gas by heating. When the second gas is an odor gas and the first gas is a non-odor gas having a temperature higher than that of the second gas passing through the deodorization path, the odor gas is moved to the casing side. Leakage can be effectively suppressed.

It is a layout figure of the gas deodorizing system using the multi-tube heat exchanger of this embodiment. It is sectional drawing of the multitubular heat exchanger of this embodiment. FIG. It is a perspective view of the multitubular heat exchanger of this embodiment. It is an enlarged view explaining the support structure of the heat exchanger tube and tube sheet of this embodiment. It is an enlarged view explaining the support structure of the heat exchanger tube and tube sheet of other embodiment. It is an enlarged view explaining the support structure of the heat exchanger tube and tube sheet of other embodiment. It is a cross section of the conventional multi-tube heat exchanger. It is a principal part enlarged view of (a) and (b).

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking as an example an embodiment suitably used as the heat exchanger b of the gas deodorization system shown in FIG.

  As shown in FIGS. 2 to 4, the multitubular heat exchanger 1 of the present embodiment includes a cylindrical casing 4 having an inlet 2 and an outlet 3 through which the first gas G1 flows in and out, and a second casing 4. A plurality of heat transfer tubes 5 that flow in the casing 4 as the gas G2 flows, and a first tube that is provided on one end 4a side (left side in FIG. 2) of the casing 4 and supports the one end 5a side of the heat transfer tube 5 The plate 6 includes a second tube plate 7 provided on the other end 4b side (right side in FIG. 2) of the casing 4 and supporting the other end 5b side of the heat transfer tube 5.

  In the multitubular heat exchanger 1 of this embodiment, the first gas G1 is an odor gas (about 150 ° C.) containing organic matter and the like, and the second gas G2 passes through the deodorization path L in FIG. Thus, the case of a non-odor gas having a higher temperature (about 750 ° C.) and detoxified than the first gas G1 is shown.

  In the present embodiment, the casing 4 is configured in a substantially rectangular parallelepiped shape that is long in the horizontal direction, and is installed on the floor surface via the base material 11. Further, the outer surface of the casing 4 is appropriately externally insulated by a heat insulating material 10 such as rock wool. However, the casing 4 can also be formed in a cylindrical shape.

  In addition, the casing 4 of the present embodiment has an inlet 2 and an outlet 3 which are provided side by side on the upper surface thereof and have a substantially rectangular opening and extend upward. A duct for guiding the first gas G1 is connected to the inlet 2 and the outlet 3 through packing or the like (both not shown).

  Furthermore, the opening on the one end 4 a side and the other end 4 b side in the horizontal direction of the casing 4 is closed by a first tube plate 6 and a second tube plate 7. A partition plate 8 is provided inside the casing 4. The partition plate 8 extends vertically so as to divide the inside of the casing 4 into two spaces between the inlet 2 and the outlet 3, and terminates before reaching the bottom surface B of the casing 4. ing. As a result, the first gas G1 fed from the inlet 2 changes its direction in the casing 4 between the lower end of the partition plate 8 and the bottom surface B, and is substantially U-shaped in a side view toward the outlet 3. It flows in a shape.

  The casing 4 is provided with an inspection port 30 covered with, for example, an openable / closable lid on the bottom side. Moreover, the connection part J for connecting with the downstream heat exchanger a (shown in FIG. 1) is provided in the one end 4a side of the casing 4. As shown in FIG.

  As shown in FIG. 4, the heat transfer tubes 5 are formed of pipes having a circular cross section, and are arranged in multiple stages and multiple rows at relatively dense pitches while being separated from each other. As a result, a gap through which the first gas G1 passes is formed between the heat transfer tubes 5 and 5.

  FIG. 5 shows an enlarged view of a main part of the first tube sheet 6 and the second tube sheet 7. Each of the tube plates 6 and 7 has a plate shape that closes the opening on the one end 4a side and the other end 4b side of the casing 4, and circular support holes 12 and 13 into which end portions of the heat transfer tubes 5 are inserted. Many are formed.

  In such a multi-tube heat exchanger 1, the high-temperature second gas G <b> 2 flowing through the heat transfer tube 5 flows in a space i surrounded by the casing 4, the first tube plate 6, and the second tube plate 7. Heat exchange is performed via the heat transfer tube 5 with the relatively low temperature first gas G1 to raise the temperature of the first gas G1.

  The support hole 12 of the first tube sheet 6 has a diameter that is substantially the same as or slightly larger than the outer diameter of the heat transfer tube 5. In the present embodiment, one end 5a of the heat transfer tube 5 is inserted into the support hole 12 of the first tube plate 6 from the inside, and one end 5a of the heat transfer tube 5 protruding outward is the above-described one of the first tube plate 6. It is fixed to the outer surface 6o, which is one end side surface, by welding. Thereby, the 1st tube plate 6 and the heat exchanger tube 5 are fixed substantially airtight.

  The second tube plate 7 also has a support hole 13 having a diameter substantially equal to or slightly larger than the outer diameter of the heat transfer tube 5 at a position facing the support hole 12 of the first tube plate 6. Is formed. The other end 5 b of the heat transfer tube 5 is slidably inserted into the support hole 13 and supported. That is, the other end side 5 b of the heat transfer tube 5 is not welded and fixed to the second tube sheet 7.

  In such a support structure, since the heat transfer tube 5 is loosely supported by the second tube plate 7, elongation due to thermal expansion of the heat transfer tube 5 is not restricted. Therefore, since an excessive stress is not generated between the tube sheets 6 and 7 or the casing 4, it is not necessary to provide an expansion joint in the casing 4, and the apparatus can be manufactured at low cost. Further, since the expansion joint is not provided, it is possible to prevent the occurrence of cracks and the like that tend to occur in the expansion joint, and to improve the durability. Further, since the heat transfer tube 5 can be extracted from the second tube plate 7, the whole or a part of the heat transfer tube 5 can be replaced, maintenance of the second tube plate 7 exposed to the high temperature side, dismantling, etc. It is also preferable in that it can be easily performed.

  The second tube plate 7 is provided with a guide tube 9. The induction tube 9 has a length L2 larger than the protruding portion 5H of the heat transfer tube 5 protruding from the second tube plate 7, and has an inner diameter d2 (d2 ≧ d1) approximate to the outer diameter d1 of the protruding portion 5H. The protruding portion 5H is slidably inserted. In addition, the guide tube 9 of the present embodiment is fixed to the outer surface 7o, which is the surface on the other end side, of the second tube sheet 7 by welding. Further, the overlapping length between the other end 5b of the heat transfer tube 5 and the induction tube 9 is represented by a symbol L1.

  Such an induction tube 9 is closely attached to the heat transfer tube 5 and has a sufficiently large overlap length L1, so that the flow resistance when the first gas G1 leaks from the gap between the two is increased, As a result, the amount of leakage can be suppressed to a very small amount. In particular, when the heat transfer tube 5 extends due to a temperature rise, the joint area between the induction tube 9 and the heat transfer tube 5 is further increased. This helps to further increase the flow resistance when the first gas G1 leaks from the gap and further limit the amount of leakage.

  The overlap length (in this embodiment, equal to the length of the protruding portion 5H) L1 and the length L2 of the guide tube 9 (both are the length at normal temperature) are not particularly limited. If it is too small, the joint area between the two tubes is reduced, and the first gas G1 is likely to leak from between them. From such a viewpoint, the overlap length L1 is preferably 20 mm or more, and more preferably 30 mm or more. The length L2 of the guide tube 9 is preferably at least twice as long as the overlap length L1.

  Note that if the overlap length L1 and the length L2 of the guide tube 9 are too large, the apparatus may be remarkably enlarged or the productivity may be deteriorated. From such a viewpoint, the overlap length L1 is preferably 50 mm or less, more preferably 40 mm or less. Similarly, the length L2 of the guide tube 9 is preferably not more than 5 times the length L1 of the protruding portion 5H.

  The inner diameter d2 of the guide tube 9 is, for example, 105 to 110%, more preferably 106 to 109%, of the outer diameter d1 of the protruding portion 5H (that is, the outer diameter of the heat transfer tube 5). If the inner diameter d2 of the guide tube 9 is less than 105% of the outer diameter d1 of the protruding portion 5H, there is a risk of restraining elongation during the thermal expansion of the heat transfer tube 5, and conversely if more than 110%, There is a possibility that the first gas G1 leaks from there.

  Further, in the multi-tube heat exchanger 1 of the present embodiment, the protruding portion 5H of the heat transfer tube 5 is heated to a higher temperature than the induction tube 9 surrounding the heat transfer tube 5 by the high temperature second gas G2. The reason is that since the high temperature second gas G2 is fed from the induction tube 9 side, the protruding portion 5H of the heat transfer tube 5 has the end surface 5b1 on the other end 5b side and the inner peripheral surface 5b2 as the second gas G2. This is because the guide tube 9 outside the protruding portion 5H is heated via the protruding portion 5H. As a result, the radial extension of the protruding portion 5H tends to be larger than the radial extension of the guide tube 9, and the gap between the two can be further reduced. Therefore, in the multi-tube heat exchanger 1 of the present embodiment, the gas resistance can be reliably suppressed by increasing the flow resistance when the first gas G1 leaks from the gap as it is used.

  In addition, the heat exchanger tube 5 and the induction tube 9 can be comprised, for example with the same metal material, For example, stainless steel, such as SUS304 and SUS310S which improved heat resistance, is used suitably. However, a metal material having a smaller coefficient of thermal expansion than the heat transfer tube 5 may be used for the induction tube 9.

  In the present embodiment, the flow rate of the second gas G2 is set to be relatively high. This generates frictional heat at the protruding portion 5H of the heat transfer tube 5 and helps to further heat the protruding portion 5H to further reduce the joint gap with the induction tube 9. Moreover, it can suppress that the 1st gas G1 leaks from the clearance gap between the heat exchanger tube 5 and the induction | guidance | derivation tube 9 by the high flow rate of the 2nd gas G2. As an example, in the present embodiment, the flow rate of the second gas G2 is adjusted to about 30 m / s, while the flow rate of the first gas G1 is set to half or less. Such a flow rate balance can effectively prevent the first gas G1 from leaking out from the joint gap between the heat transfer tube 5 and the induction tube 9 to the induction tube 9 side.

  Even if the first gas G1 leaks from the joint gap between the heat transfer tube 5 and the induction tube 9 to the induction tube 9 side, the amount is very small and the leaked first gas G1 is The high-temperature heated second gas G2 flows through the protruding portion 5H of the induction tube 9 and the heat transfer tube 5 and is deodorized in the middle of the heat transfer tube 5 so as to be released into the atmosphere together with other deodorized gases.

  The heat transfer tubes 5 are arranged at a relatively dense pitch as described above. For this reason, welding with the induction | guidance | derivation pipe | tube 9 and the 2nd tube sheet 7 must be performed in a very narrow space, and there exists some difficulty in productivity. Therefore, for example, as shown in FIG. 6, the end surface 9 a on the second tube plate 7 side of the guide tube 9 is not substantially welded to the second tube plate 7 and is substantially parallel to the second tube plate 7. It can also be held by the extending support plate 15.

  The support plate 15 is formed with a support hole 16 into which the guide tube 9 can be closely inserted and fixed. The periphery of the support plate 15 is fixed to the inner surface of the casing 7 (not shown). Thereby, the end surface 9 a of the guide tube 9 can be brought into contact with the outer surface 7 o of the second tube plate 7. In addition, when the length which protrudes outside the support plate 15 of the guide tube 9 is made small, the support plate 15 and the guide tube 9 can also be welded on the outside.

  The multitubular heat exchanger 1 as described above can be suitably used in the gas deodorization system S described above.

Various modifications can be further made in the multi-tube heat exchanger 1 of the present embodiment.
For example, as shown in FIGS. 2 and 4, an auxiliary tube plate 20 can be provided in the vicinity of the second tube plate 7. As a result, the first gas G <b> 1 is small in the casing 4 between the partition plate 8 and the auxiliary tube plate 20 toward the outlet 3 from the space between the partition plate 8 and the auxiliary tube plate 20, and the auxiliary tube plate 20 and the second tube plate 7. The auxiliary flow path A1 from the gap toward the outlet 3 is divided. Further, the casing 4 is provided with a bypass port 22 through which the first gas G1 flows, on the bottom side of the heat exchanging part provided with the heat transfer tubes 5 and on the back side in FIG. Further, a duct portion 23 that guides the first gas G1 flowing from the bypass port 22 to the auxiliary flow path A2 is provided in the casing 4. In addition, the auxiliary tube plate 20 supports the heat transfer tube 5 in an auxiliary manner and suppresses deformation of the heat transfer tube. Accordingly, the heat transfer tube 5 can slide more smoothly in the induction tube 9. Further, it serves to reduce the temperature of the tube sheet 7 by projecting and reflecting the radiant heat of the tube sheet 7 on the entire surface.

  The second gas G2 having a very high temperature of about 750 ° C. is supplied to the second tube plate 7 side of the heat transfer tube 5. Therefore, thermal fatigue tends to progress relatively early in the second tube plate 7 and the heat transfer tube 5 in the vicinity thereof. Therefore, for example, the first gas G1 having a relatively low temperature that is not substantially heat exchanged with the heat transfer tube 5 is taken in from the front bypass port 22 and directly led to the auxiliary flow path A2 to obtain the second gas G1. The tube plate 7 and the heat transfer tube 5 in the vicinity thereof can be effectively cooled. Thereby, durability of a heat exchanger can be improved.

  In the above embodiment, the first gas G1 is an odor gas, and the second gas is a high-temperature non-odor gas passed through the deodorization furnace M. However, the present invention is not limited to such an embodiment. The gas can be different from each other. That is, the second gas G2 is an odor gas, and the first gas G1 passing through the casing 4 is a non-odor gas whose temperature is higher than that of the second gas by passing the second gas G2 through the deodorization path M. It is also good. FIG. 7 shows a preferred embodiment of such an aspect.

  In the embodiment of FIG. 7, the guide tube 9 is inserted into a support hole 13 provided in the second tube sheet 7 and welded and fixed to the second tube sheet. More specifically, the guide tube 9 protrudes from the support hole 13 to the first tube sheet 6 side with a small length, and this portion is welded to the inner surface 7 i of the second tube sheet 7. . That is, the support hole 13 of the second tube sheet 7 is formed larger than the support hole 13 of the first tube sheet 6. Such a welded structure is useful for preventing the first gas from leaking from the gap between the second tube sheet 7 and the guide tube 9. However, needless to say, the guide tube 9 and the second tube plate 7 may be welded to each other on the outer surface 7o (the other end surface) of the second tube plate 7.

  Also in this embodiment, the length L1 of the overlapping portion of the heat transfer tube 5 and the induction tube 9, the length L2 of the induction tube 9 (both are the length at normal temperature), the inner diameter d2 of the induction tube 9, and the protruding portion 5H As for the outer diameter d1 (that is, the outer diameter of the heat transfer tube 5), the value described as the above-mentioned preferable range can be applied as it is.

  In this embodiment, the second gas G2 is fed from the first tube plate 6 side to the second tube plate 7 side. The flow rate of the second gas G2 is set to be greater than at least the flow rate of the first gas G1. Accordingly, it is possible to prevent the second gas G2 containing odor from flowing back from the joint gap between the heat transfer tube 5 and the induction tube 9 and leaking into the casing 4. In a preferred embodiment, the second gas G2 is desirably adjusted to at least 1.5 times, more preferably at least twice the flow rate of the first gas G1.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to said embodiment, It can implement by applying to a various aspect. For example, it goes without saying that the present invention can be applied to general air preheaters, exhaust gas coolers, and the like.

DESCRIPTION OF SYMBOLS 1 Multitubular heat exchanger 2 Inlet 3 Outlet 4 Inside casing 4a One end of casing 4b Other end 5 of casing 5 Heat transfer tube 5a One end 5b of heat transfer tube 5H Other end 5H of heat transfer tube 6 First tube sheet 7 Second tube Tube plate 7i Inner side surface 7o Outer side surface 8 Partition plate 12 Support hole 13 Support hole 20 Auxiliary tube plate G1 First gas G2 Second gas M Deodorizing furnace

Claims (9)

A cylindrical casing having an inlet and an outlet through which the first gas flows in and out;
A plurality of pipe-shaped heat transfer tubes extending through the casing as the second gas flows;
A first tube sheet provided on one end of the casing and supporting one end of the heat transfer tube;
A second tube plate provided on the other end side of the casing and supporting the other end side of the heat transfer tube;
The multi-tube heat exchanger in which the second gas exchanges heat with the first gas flowing through the space surrounded by the casing, the first tube plate, and the second tube plate via the heat transfer tube. Because
While the first tube plate and the one end side of each heat transfer tube are fixed,
The other end side of each of the heat transfer tubes is slidable on the second tube plate and supported by protruding to the other end side, and the heat transfer tube protruding from the second tube plate is supported on the second tube plate. A multi-tube heat exchanger characterized in that a guide tube is provided which has an inner diameter that is longer than the protruding portion and has an inner diameter that approximates the outer diameter of the protruding portion, and is slidably inserted into the protruding portion. .   2. The multi-tube heat exchanger according to claim 1, wherein the induction tube is abutted against a surface on the other end side of the second tube plate and is welded and fixed to the second tube plate.   2. The multi-tube heat exchanger according to claim 1, wherein the induction pipe is held in contact with a surface on the other end side of the second tube sheet by a support fitting fixed to the casing.   The second gas is fed from the second tube sheet side to the first tube sheet side at a flow rate that prevents the first gas from leaking from the gap between the heat transfer tube and the induction tube. The multitubular heat exchanger according to claim 1. A gas deodorization system comprising the multi-tubular heat exchanger according to claim 4 and a deodorization furnace for deodorizing by heating odor gas,
The first gas is an odor gas, and the second gas is a non-odor gas having a temperature higher than that of the first gas obtained by passing the first gas through the deodorization path. Deodorization system.   2. The multi-tube heat exchanger according to claim 1, wherein the induction tube is inserted into a support hole provided in the second tube plate and welded to a surface on the one end side of the second tube plate.   2. The multi-tube heat exchanger according to claim 1, wherein the induction tube is inserted into a support hole provided in the second tube plate and welded to a surface on the other end side of the second tube plate.   The second gas is flowed at a flow rate that prevents the second gas from leaking between the first tube sheet and the second tube sheet from the gap between the heat transfer tube and the induction tube. The multi-tube heat exchanger according to claim 6 or 7, wherein the multi-tube heat exchanger is fed from one tube sheet side to the second tube sheet side. A gas deodorization system comprising the multi-tubular heat exchanger according to claim 8 and a deodorization furnace for deodorizing by heating odor gas,
The second gas is an odor gas, and the first gas is a non-odor gas having a temperature higher than that of the second gas obtained by passing the second gas through the deodorization path. Deodorization system.

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