JP5996597B2 - Rotating regenerative air preheater - Google Patents

Description

  The present invention relates to an air preheater that heats combustion air using exhaust gas from a boiler, and more particularly, to a rotary regenerative air preheater that rotates a rotor containing a heat transfer element about an axis.

  An air preheater is a device that preheats air to be burned in a boiler by exchanging heat with the gas discharged from the boiler in a thermal power plant or the like. Separated. Among these, the regenerative air preheater has a structure in which heat transfer elements are alternately brought into contact with exhaust gas and combustion air. And the thing of the structure which rotates the rotor in which the heat-transfer element was accommodated around the axis | shaft is called the rotation regenerative type air preheater especially.

A general structure of a rotary regenerative air preheater installed so that the rotation axis of the rotor is parallel to the vertical direction will be described with reference to FIGS.
FIG. 3A is a perspective view schematically showing a rotary regenerative air preheater according to the prior art, and FIG. 3B shows a state in which a part of FIG. 3A is cut along a plane parallel to the diaphragm. FIG. In FIG. 3A, the downward arrow indicates the flow of high-temperature gas discharged from the boiler, and the upward arrow indicates the flow of low-temperature air burned by the boiler.
As shown in FIG. 3A, the rotary regenerative air preheater includes a thin-walled cylindrical shell 52 having a columnar post 51 as a central axis, and a shell 52 extending radially from the post 51 to the shell 52. The rotor 50 including a plurality of diaphragms 54 that divide the inside of the sector into sector-shaped sectors 53 and a plurality of heat transfer elements and a basket module 55 installed in each sector 53 includes posts 51. It is structured to be installed inside the housing 56 so as to be rotatable as a center.

  The heat transfer element is a rectangular plate having a plurality of pleats, and is arranged so as to be parallel to the axial direction of the rotor 50 and surround the post 51. In addition, at least a pair of sector plates 57 and 57 are installed on the upper and lower surfaces of the housing 56 in a substantially symmetrical manner with the rotor 50 in between, and the sector plates 57 allow each sector 53 to combust with the exhaust gas flow path and the combustion. Each is divided into air flow paths. That is, the rotary regenerative air preheater has a structure in which exhaust gas and combustion air flow into the rotor 50 from opposite directions while being completely separated by the sector plate 57 as indicated by arrows.

In general, the basket module 55 is often installed inside the sector 53 in a state of being divided into a plurality of layers. For example, as shown in FIG. 3 (b), the high temperature layer 55a and the low temperature layer 55c are installed adjacent to the exhaust gas inlet, the combustion air outlet, the exhaust gas outlet, and the combustion air inlet, respectively. An intermediate layer 55b is installed between 55c. The low temperature layer 55c is placed on a support member called a grating 58 formed so that a plurality of steel materials are assembled in a lattice shape.
In this case, since the exhaust gas that has passed through the high temperature layer 55a and the intermediate layer 55b has the lowest temperature in the low temperature layer 55c, condensed fine particles and the like are concentrated and adhered to the low temperature layer 55c. Therefore, for the purpose of blowing off these fine particles and the like with compressed air or dry steam, a soot blower is usually installed on the low temperature side of the rotor 50 so that steam or the like can be injected toward the heat transfer element of the low temperature layer 55c.

4A is a partial plan view of the rotary regenerative air preheater shown in FIG. 3A, and FIG. 4B is a view in the direction of arrow D in FIG. 4A. However, in these drawings, the basket module 55 and the housing 56 are omitted, and only one portion of the grating 58 is illustrated. Further, in FIG. 4B, illustration of the shell 52 is omitted.
As shown in FIGS. 4A and 4B, a plurality of rectangular through holes 61 are provided in the lower part of the diaphragm 54 at a predetermined interval in a row in the horizontal direction. A rectangular parallelepiped support member (hereinafter referred to as a support block 59) is inserted into 61 so that both ends thereof protrude from the surface of the diaphragm 54.
The grating 58 has a trapezoidal shape in plan view, and a lower end on the side close to the diaphragm 54 is supported from below by a support block 59 and is pitch welded to the diaphragm 54. Further, an end plate 60 is installed near the lower end of the diaphragm 54 so as to close the gap between the grating 58 and the post 51.

5 (a) and 5 (b) are enlarged views of the E portion in FIG. 4 (a) and the F portion in FIG. 4 (b), respectively, and FIG. 5 (c) is a G- It is G line arrow sectional drawing. In addition, the grating 58 is shown with the broken line in FIG.5 (b) and FIG.5 (c).
The grating 58 needs to be fixed to the diaphragm 54 so as not to move as the rotor 50 rotates. However, in consideration of workability when the rotor 50 is maintained and inspected, it is desirable that the grating 58 be removed from the rotor 50 as necessary. Therefore, the grating 58 is usually intermittently welded to the diaphragm 54 at a predetermined pitch.

  When the grating 58 is pitch-welded to the diaphragm 54, an unwelded portion between the diaphragm 54 and the grating 58 becomes a gap L as shown in FIGS. 5 (a) and 5 (c). In this case, the exhaust gas containing fine particles such as coal ash supplied to the rotor 50 passes through the gap L as shown by solid arrows in FIGS. 5B and 5C, and the support block 59 It passes through the part that is not installed. At this time, the diaphragm 54 and the grating 58 are eroded violently by friction with fine particles such as coal ash.

Further, when the exhaust gas containing fine particles such as coal ash passes through the gap L between the diaphragm 54 and the grating 58, the condensed fine particles adhere to the support block 59 and the surrounding diaphragm 54. As described above, when steam or the like is blown onto the lower surface of the rotor 50 with a soot blower at a high pressure in order to blow off the fine particles adhering to the low temperature layer 55c, the high pressure vapor is adhering to the support block 59 and the surrounding diaphragm 54. 5B and FIG. 5C, the air flows into the gap L from the portion where the support block 59 is not installed, as shown by the dashed arrows in FIGS. As a result, the diaphragm 54 and the grating 58 are severely eroded by friction with the fine particles such as coal ash.
As described above, in the conventional rotary regenerative air preheater, when exhaust gas is supplied to the rotor 50 or high pressure steam or the like is blown by the soot blower, the gap L between the diaphragm 54 and the grating 58 forms exhaust gas or There is a problem that the diaphragm 54 around the support block 59 is eroded by coal ash or the like contained in the exhaust gas due to a flow path of steam or the like.

Corrosion (ash erosion) with coal ash is a problem to be solved in various devices as well, not limited to the regenerative air preheater. For example, Patent Literature 1 discloses an invention for reducing ash erosion in a coal-fired boiler having a heat transfer tube wear prevention device under the name of “coal-fired boiler”.
The invention disclosed in Patent Document 1 is an L-shape in which the other bent piece portion is welded and fixed to the heat transfer wall so that the one bent piece portion having a plurality of holes is orthogonal to the heat transfer wall. It is characterized by having an anti-wear plate.
According to such a structure, since the amount of gas flowing through the gap between the heat transfer tube and the heat transfer wall is suppressed, wear of the heat transfer device and the peripheral wall can be prevented.

Patent Document 2 discloses an invention for preventing gas flow drift and erosion in the flue part of a coal-fired boiler under the name of “coal-fired boiler flue part drift prevention device”.
The invention disclosed in Patent Document 2 includes a plurality of current-preventing plates having a cross-section of “H” in the cross section so as to be substantially orthogonal to the gas flow in the gap between the flue wall and the panel-shaped heat transfer tube group. Is characterized by being installed horizontally.
According to such a structure, since the gas flow rate to the gap between the heat transfer tube group and the flue wall does not increase, the erosion of the flue wall can be reduced.

Furthermore, Patent Document 3 describes the erosion caused by gas flow drift and coal ash in the flue part of a coal-fired boiler used for business or private power generation under the name of “coal-fired boiler flue part drift prevention device”. An invention relating to an apparatus for preventing is disclosed.
The invention disclosed in Patent Document 3 is characterized in that a plurality of perforated plates are installed substantially perpendicular to the gas flow in the gap between the panel-like heat transfer tube group and the flue wall.
According to such a structure, it is possible to prevent the gas flow rate from increasing in the above-described gap, and to reduce erosion of the heat transfer tube wall.

Patent Document 4 discloses a reheater and a superheater having a name of “a loop pipe wear preventing device for a rear heat transfer section” connected to the rear side of the furnace via a sub-side wall and including a plurality of loop pipes inside. The invention regarding the coal fired boiler provided with the rear heat-transfer part by which is arranged is disclosed.
In the invention disclosed in Patent Document 4, an erosion baffle having a coal ash flow hole drilled in the front surface at a position above the bent end of the loop tube of the reheater and the superheater on the heat transfer tube wall is substantially horizontal. It is characterized by being attached so as to protrude into the flow path in the direction.
According to such a structure, the combustion gas with a gentle and sufficient flow rate passes through the gap between the heat transfer tube wall and the bent end of the loop tube, so that the pressure loss is reduced and Wear of the bent end due to the coal ash contained in is prevented.

Japanese Patent Laid-Open No. 2005-055132 Japanese Patent Application Laid-Open No. 09-210340 JP 09-196357 A Japanese Patent Laid-Open No. 08-110007

  In the invention disclosed in Patent Document 1, if the gap between the heat transfer tube and the heat transfer wall is completely closed, the combustion gas does not flow through that portion. As a result, the contact area of the heat transfer tube with respect to the combustion gas decreases, and the heat exchange efficiency decreases. That is, in the invention disclosed in Patent Document 1, since the combustion gas flow in the gap between the heat transfer tube and the heat transfer wall must be allowed to some extent, the porous wear-resistant plate is connected to the heat transfer tube and the heat transfer plate. By installing it in the gap with the wall, the flow of combustion gas is suppressed. However, with such a structure, it is not possible to completely prevent wear of the heat transfer device and the peripheral wall that are generated in contact with the combustion gas.

  Further, in the invention disclosed in Patent Document 2, an increase in the gas flow rate is suppressed by the drift prevention plate installed in the gap between the flue wall and the panel-shaped heat transfer tube group, so the erosion of the flue wall is surely Can be reduced to some extent. However, even in this invention, in order to ensure a certain contact area of the heat transfer tube with respect to the gas, the gap between the flue wall and the panel-like heat transfer tube group is not completely blocked by the drift prevention plate. The gas flow is allowed to some extent. Therefore, there is a problem that erosion of the flue wall cannot be sufficiently prevented.

  In the invention disclosed in Patent Document 3, a perforated plate is installed in the gap between the heat transfer tube group and the flue wall, and erosion occurs on the heat transfer tube wall by suppressing the accelerated flow of the gas flowing through that portion. However, the perforated plate cannot completely block the gas flow. Therefore, even in this invention, there is a problem that erosion on the heat transfer tube wall cannot be completely prevented.

  Further, in the invention disclosed in Patent Document 4, the erosion baffle is installed at the upper position of the bent end portion of the loop pipe, but the erosion baffle is made of coal so that heat exchange with the loop pipe is sufficiently performed. An ash circulation hole is provided to ensure a predetermined gas flow rate. Therefore, it is not possible to completely prevent the occurrence of wear at the bent end portion of the loop pipe due to the contact with the coal ash contained in the combustion gas.

As described above, the inventions disclosed in Patent Documents 1 to 4 do not have the idea of completely blocking the gap between the heat transfer tube and the flue wall and completely blocking the flow of combustion gas into that portion. . Therefore, in these inventions, erosion (ash erosion) due to coal ash or the like generated in the diaphragm or grating of the regenerative air preheater cannot be prevented.
That is, the present invention has been made in response to such a conventional situation, and efficiently prevents erosion (ash erosion) of diaphragms and gratings caused by friction with fine particles such as coal ash contained in exhaust gas. An object of the present invention is to provide a rotary regenerative air preheater capable of performing the above.

In order to achieve the above object, according to the first aspect of the present invention, a rotor is rotatably installed in a housing, and a high temperature fluid and a low temperature fluid are alternately brought into contact with a heat transfer element accommodated in the rotor, In the rotary regenerative air preheater that exchanges heat between the two, the rotor includes a thin cylindrical body that is accommodated in the housing, a cylindrical body that is concentrically installed inside the cylindrical body, and the cylindrical body. A diaphragm that extends radially from the outer peripheral surface of the cylindrical body and divides the inside of the cylindrical body into a plurality of sectors in a fan shape in plan view, a basket module that is installed in the sector and accommodates a heat transfer element, and the basket module A grating installed in the sector so that it can be placed on the top, and a flat top surface that can support this grating, and the sector below the diaphragm A plurality provided is support members in one row in the horizontal direction so as to protrude, a rectangular parallelepiped shape, being in contact respectively the rear and end face to the support member and the diaphragm, the upper surface flush with the upper surface support member And a long metal member installed in such a manner .

As mentioned above, it is necessary to fix the grating to the diaphragm so that it does not move when the rotor rotates.However, considering the workability when maintaining and inspecting the rotor, the grating is attached to the diaphragm. In contrast, intermittent welding is often performed at a predetermined pitch. In this case, a portion where the grating is not welded to the diaphragm becomes a flow path of the exhaust gas supplied to the rotor, and the lower portion of the diaphragm is eroded by friction with coal ash and the like contained in the exhaust gas.
However, in the rotary regenerative air preheater having the above structure, the upper surface of the long member of the rectangular parallelepiped is flush with the upper surface of the support member. Adheres to the lower surface. Therefore, since the gap generated in the portion where the grating is not welded to the diaphragm is blocked by the long member, exhaust gas supplied to the boiler, high-temperature steam blown to the rotor by the soot blower, etc. may flow into the portion. There is no. The long member is installed so as not to protrude upward beyond the upper surface of the support member, and since the support member supports the grating load, the long member is fixed to the diaphragm by the grating load. There is no risk of damage (such as welds).

According to a second aspect of the present invention, in the rotary regenerative air preheater according to the first aspect of the present invention, the elongate member is characterized in that the lower edge of the surface contacting the diaphragm is fillet welded. It is.
In the rotary regenerative air preheater having such a structure, the gap between the grating and the diaphragm is more reliably closed by the long member as compared with the invention described in claim 1, so that the exhaust gas to the relevant location, etc. The effect of the invention as set forth in claim 1 is further exerted by the long member.

According to a third aspect of the present invention, in the rotary regenerative air preheater according to the first or second aspect of the present invention, the long member is fillet welded at the periphery except for the upper edge of the surface contacting the support member. It is characterized by this.
In the rotary regenerative air preheater having such a structure, the long member reliably closes the gap between the grating and the diaphragm to prevent the exhaust gas or the like from flowing into the portion. The effect | action of the made invention is further exhibited.

According to a fourth aspect of the present invention, in the rotary regenerative air preheater according to any one of the first to third aspects, the long member is made of steel.
In the rotary regenerative air preheater having such a structure, in addition to the operation of the invention described in any one of claims 1 to 3, the long member is difficult to wear, so that the service life of the rotor Has the effect of stretching.

According to a fifth aspect of the present invention, in the rotary regenerative air preheater according to any one of the first to fourth aspects, a plurality of through holes are formed in a row in a horizontal direction at a lower portion of the diaphragm. The support member has a rectangular parallelepiped shape, and is inserted into the through hole so as to project both ends from the surface of the diaphragm.
In the rotary regenerative air preheater having such a structure, in addition to the operation of the invention described in any one of claims 1 to 4 , the support member is firmly fixed to the diaphragm. Has an effect.

  According to the first aspect of the present invention, the passage of exhaust gas or the like is not formed in the gap between the grating and the diaphragm, and erosion of the diaphragm (ash erosion) generated by friction with coal ash or the like contained in the exhaust gas. ) Can be efficiently prevented. Further, it is not necessary to support the grating load with the long member, and the fixing method of the long member with respect to the diaphragm can be simplified, so that the manufacturing cost of the rotor can be reduced.

  According to the invention described in claim 2 of the present invention, the gap between the grating and the diaphragm is reliably closed by the long member, and the flow of exhaust gas or the like is prevented, thereby preventing the occurrence of ash erosion at the location. The effect of the invention described in claim 1 can be further exhibited.

  According to the third aspect of the present invention, the long member acts so as to reliably block the gap between the grating and the diaphragm and to prevent the exhaust gas and the like from flowing in, so that the occurrence of ash erosion at the location can be prevented. The effect of the invention described in claim 1 or claim 2 is further exhibited.

  According to the invention described in claim 4 of the present invention, in addition to the effect of the invention described in any one of claims 1 to 3, the rotor is unlikely to break down, so that periodic inspections, maintenance work, etc. There is an effect that it is possible to reduce the cost required for.

According to the invention described in claim 5 of the present invention, in addition to the effects of the invention described in any one of claims 1 to 4 , the support member is strong against the diaphragm by a simple structure. Since it is fixed, the effect that the load of grating can be supported safely and reliably by the support member is exhibited.

(A) is a partial top view of the Example of the rotation regeneration type | mold air preheater which concerns on embodiment of this invention, (b) is a perspective view which shows the positional relationship of a flat bar and a support block. (A) is an A direction arrow directional view in Fig.1 (a), (b) is an enlarged view of the B section in Fig.1 (a), (c) is the CC line in FIG.1 (b). It is arrow sectional drawing. (A) is a perspective view which shows the outline of the rotary regenerative air preheater which concerns on a prior art, (b) is a figure which shows the state which cut | disconnected a part of the figure (a) by the surface parallel to a diaphragm. . (A) is a partial top view of the rotation regeneration type air preheater shown to Fig.3 (a), (b) is a D direction arrow directional view in the same figure (a). (A) And (b) is an enlarged view of E section in Drawing 4 (a) and F section in Drawing 4 (b), respectively, (c) is a GG line arrow sectional view in Drawing 4 (b). It is.

  The configuration of the rotary regenerative air preheater of the present invention, and the action and effect based thereon will be specifically described with reference to FIG. 1 and FIG. In this embodiment, as already described with reference to FIGS. 3 to 5, the rotation axis of the rotor is parallel to the vertical direction, and a basket module containing a plurality of heat transfer elements is formed by grating in each sector. Although a rotary regenerative air preheater having a structure supported from below is assumed, the following description is similarly applied to a rotary regenerative air preheater in which the rotation axis of the rotor is parallel to the horizontal direction.

Fig.1 (a) shows a part of top view of the Example of the rotation regeneration type | mold air preheater based on embodiment of this invention, FIG.1 (b) is the positional relationship of a flat bar and a support block. FIG. 5 is an enlarged perspective view showing a portion where a flat bar and a support block are attached to a diaphragm. 2 (a) is an enlarged view of a part of the view in the direction of arrow A in FIG. 1 (a), and FIG. 2 (b) is an enlarged view of part B in FIG. 1 (a). FIG.2 (c) is CC sectional view taken on the line in FIG.1 (b).
2 (a) corresponds to FIG. 5 (b), FIG. 2 (b) corresponds to FIG. 5 (a), and FIG. 2 (c) corresponds to FIG. 5 (c). Further, in FIGS. 2A to 2C, the grating is indicated by a broken line. Further, the components shown in FIGS. 3 to 5 are denoted by the same reference numerals and the description thereof is omitted.

As shown in FIGS. 1 and 2, the rotary regenerative air preheater according to the present invention is the same as the rotary regenerative air preheater according to the related art shown in FIGS. The flat bar 1 has a structure in which the support block 59 of the diaphragm 54 is not provided.
The flat bar 1 is installed in the lower part of the diaphragm 54 so as not to protrude upward beyond the upper surface 59a of the support block 59 in a state where the end surface 1b and the back surface 1c are in contact with the support block 59 and the diaphragm 54, respectively. Specifically, the flat bar 1 has corners on the periphery (for example, the front edge and the lower edge) excluding the lower edge of the back surface 1c that contacts the diaphragm 54 and the upper edge of the end surface 1b that contacts the end surface 59b of the support block 59. While the meat welding 2 is performed, the upper surface 1 a is installed so as to be flush with the upper surface 59 a of the support block 59.

  In the rotary regenerative air preheater having such a structure, since the gap L between the diaphragm 54 and the grating 58 is closed by the flat bar 1, the high temperature blown to the rotor 50 by the exhaust gas or the soot blower supplied to the boiler. The flow of steam or the like is interrupted, and the flow into the portion is prevented. Since the flat bar 1 is installed so as not to protrude upward beyond the upper surface 59a of the support block 59, the load of the grating 58 is supported by the support block 59 without receiving the load of the grating 58. Therefore, it is not necessary to firmly fix the flat bar 1 to the diaphragm 54. Further, the flat bar 1 can be made thin and wide. In this case, the flat bar 1 is attached to the diaphragm 54 so that its wide surface comes into contact with the grating 58 while reducing the weight of the flat bar 1. It can be easily handled.

  Further, since the flat bar 1 has a rectangular parallelepiped shape and the upper surface 1a is flush with the upper surface 59a of the support block 59, when the grating 58 is placed on the upper surface 59a of the support block 59, the upper surface 1a of the flat bar 1 Is in close contact with the lower surface 58a of the grating 58 together with the upper surface 59a of the support block 59. In addition, since the flat bar 1 is provided with fillet welds 2 on the periphery of the back surface 1c and the end surface 1b that contact the diaphragm 54 and the support block 59, in the rotary regenerative air preheater of the present invention, The gap L of the grating 58 has an effect of being reliably closed by the flat bar 1.

  As described above, according to the rotary regenerative air preheater of the present invention, the flow path of the exhaust gas or the like is not formed in the gap L between the grating 58 and the diaphragm 54, and the coal ash or the like contained in the exhaust gas It is possible to efficiently prevent erosion (ash erosion) of the diaphragm 54 caused by the friction. Moreover, since it is not necessary to support the load of the grating 58 by the flat bar 1, the fixing method with respect to the diaphragm 54 of the flat bar 1 can be simplified, and the manufacturing cost of the rotor 50 can be made cheap.

In this embodiment, the flat bar 1 is made of metal. However, if it is made of steel, for example, it becomes difficult to wear, and the useful life of the rotor 50 is extended. Therefore, the cost required for periodic inspections and maintenance work is reduced. be able to.
In this embodiment, the flat bar 1 is fixed to the diaphragm 54 by welding. However, the present invention is not limited to this method. For example, the flat bar 1 is attached to the diaphragm 54 or the support block 59 using bolts or the like. You may fix to. However, when welding is used to fix the flat bar 1 as in the present embodiment, the flat bar 1 can be fixed so as not to cause a gap with respect to the diaphragm 54 and the support block 59, and the work cost can be reduced. There is. Note that there is no possibility that the welded portion of the flat bar 1 with respect to the diaphragm 54 or the support block 59 is damaged by the load of the grating 58.
Furthermore, in this embodiment, the support block 59 is inserted into the through hole 61 formed in the lower part of the diaphragm 54. However, the fixing of the support block 59 to the diaphragm 54 is not limited to such a method. And can be changed as appropriate. However, as shown in the present embodiment, when the support block 59 is inserted into the through-hole 61 formed in the diaphragm 54, the support block 59 is attached to the diaphragm 54 with a simple structure. Since it is firmly fixed, the load of the grating 58 can be safely and reliably supported by the support block 59.

The inventions described in claims 1 to 5 of the present invention are applicable not only to boilers used in power plants but also to various boilers.

DESCRIPTION OF SYMBOLS 1 ... Flat bar 1a ... Upper surface 1b ... End surface 1c ... Back surface 2 ... Fillet welding 50 ... Rotor 51 ... Post 52 ... Shell 53 ... Sector 54 ... Diaphragm 55 ... Basket module 55a ... High temperature layer 55b ... Intermediate layer 55c ... Low temperature layer 56 ... Housing 57 ... Sector plate 58 ... Grating 58a ... Lower surface 59 ... Support block 59a ... Upper surface 59b ... Side 60 ... End plate 61 ... Through hole L ... Gap

Claims (5)

In a rotary regenerative air preheater in which a rotor is rotatably installed in a housing, high temperature fluid and low temperature fluid are alternately brought into contact with a heat transfer element accommodated in the rotor, and heat is exchanged between the two. ,
The rotor is
A thin cylindrical body housed in the housing;
A cylindrical body installed concentrically inside the cylindrical body;
A diaphragm that radially extends from the outer peripheral surface of the cylindrical body and divides the inside of the cylindrical body into a plurality of sectors in a fan shape in plan view;
A basket module installed in the sector and containing the heat transfer element;
Grating installed in the sector so that the basket module can be placed on the top,
The upper surface is formed flat so as to be able to support this grating, and a plurality of support members provided in a row in a horizontal direction so as to protrude into the sector below the diaphragm,
A metal long member that has a rectangular parallelepiped shape and is installed so that the upper surface thereof is flush with the upper surface of the support member , with the end surface and the back surface being in contact with the support member and the diaphragm, respectively. A regenerative air preheater characterized by comprising:   The rotary regenerative air preheater according to claim 1, wherein the elongate member is fillet welded at the lower edge of the surface that contacts the diaphragm.   3. The rotary regenerative air preheater according to claim 1, wherein a peripheral edge of the elongate member excluding an upper edge of a surface that contacts the support member is fillet welded.   The rotary regenerative air preheater according to any one of claims 1 to 3, wherein the long member is made of steel. In the lower part of the diaphragm, a plurality of through holes are formed in a row in the horizontal direction,
The rotation reproduction according to any one of claims 1 to 4, wherein the support member has a rectangular parallelepiped shape, and is inserted into the through hole so that both ends protrude from the surface of the diaphragm. Air preheater.

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