JP3332886B2 - Heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger which is installed, for example, in a portion of an exhaust gas passage of 900 ° C. or higher from an incinerator and is used as a waste heat boiler for efficiently collecting high heat energy. In more detail,
The present invention relates to a heat exchanger having a heat exchange tube formed so as to meander on a plane by a plurality of straight tube portions and a folded tube portion connecting these.

[0002]

2. Description of the Related Art A conventional meandering heat exchange tube used in a heat exchanger for recovering high heat energy has a plurality of straight pipes parallel to each other and a folded pipe connecting these pipes on a plane. Although it is formed in a meandering shape, the spacing between adjacent straight pipe parts is wide, so to secure a constant heat transfer area, it is necessary to enlarge the entire tube and take up the installation space, Further, there is a problem that dust easily accumulates between the straight pipe portions, and it is difficult to remove the accumulated dust with a normal scraper used in this type of heat exchanger.

[0003] A plate-type heat exchanger is known as a heat exchanger having a compact structure and good heat exchange efficiency. A heat exchange plate of this heat exchanger has a heating steam inside a flow passage. When such a high-pressure fluid is generated, the weld between the plates is easily damaged and peeled off by the high-pressure fluid, so that it is not suitable as a heat exchanger for exhaust heat recovery.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a heat exchange tube capable of improving heat exchange efficiency by making a tube heat transfer area large and effective, and easily removing dust adhering to the tube surface by an ordinary scraper. It is an object of the present invention to provide a heat exchanger provided with:

[0005]

According to the first aspect of the present invention, there is provided a heat exchanger comprising a plurality of straight pipe portions arranged in parallel at a predetermined interval.
a and a plurality of first plane meandering tubes 1 formed so as to meander on the plane P1 by a folded tube portion 1b connecting the adjacent end portions of the straight tube portions 1a to each other at a predetermined interval in parallel with each other. The first planar meandering tubes 1
A plurality of straight pipe portions 2a arranged in parallel at intervals corresponding to each other and a folded tube portion 2b connecting adjacent ends of these straight pipe portions 2a are formed so as to meander on the plane P2. The straight pipe portions 2a of the second flat meandering tube 2 are arranged so that the plurality of second flat meandering tubes 2 are orthogonal to the first flat meandering tube 1, respectively. 1a mutual viewed <br/> embedded so as to be interposed in parallel between the second planar serpentine tube 2 that the straight tube portions 2a
Is between adjacent straight pipe portions 1a of each first planar meandering tube 1.
Assembled to the first flat meandering tube 1 so as to be interposed in parallel to
Between the opposing surfaces of the first planar meandering tube 1
Removal of dust adhering to the tube in the space 7 formed
Insert the scraper 8 for
Reciprocating along the side of the first and second meandering tubes 1 and 2
It is characterized by being driven .

According to a second aspect of the present invention, in the heat exchanger according to the first aspect, the first planar meandering tubes 1 and the second planar meandering tubes 2 are connected to each other by communicating tubes 1c and 2c, respectively. Features.

A third aspect of the present invention relates to the heat exchanger according to the first aspect, wherein each of the entrances and exits 3in, 3o of the first plane meandering tube 11 is provided.
ut and each entrance 4in, 4out of the second plane meandering tube 22
Are connected and connected by merging units 23, 24, 25 and 26, respectively.

[0008]

According to a fourth aspect, in the heat exchanger according to any one of the first to third aspects, the plurality of first planar meandering tubes 1 and the plurality of second planar meandering tubes 2 incorporated therein are combined. Both ends of each tube 1 and 2 including the folded tube portions 1b and 2b of the two tubes 1 and 2 are disposed in the furnace wall 10 of the heat exchanger body 6 while being disposed at a predetermined position in the heat exchanger body 6. It is characterized by being embedded in a heat insulating material layer 11 disposed along the side surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIGS. 1 (A) and 1 (B) show FIGS.
The first heat exchange tube of the heat exchanger shown in FIG.
The figure shows a state in which a plurality of planar meandering tubes 1 and second planar meandering tubes 2 are respectively arranged in parallel at predetermined intervals.
As shown in FIG. 3A, each first planar meandering tube 1 includes a plurality of straight pipe portions 1a arranged in parallel at regular intervals.
The straight tube portion 1a is formed so as to meander on each plane P1 by the folded tube portion 1b connecting the adjacent ends. The second meandering tube 2 is shown in FIG.
(B), a plurality of straight pipes 2a arranged in parallel at a spacing corresponding to the facing distance between the first planar meandering tubes 1 and adjacent ends of the straight pipes 2a are connected to each other. It is formed so as to meander on each plane P2 by the folded tube portion 2b. The straight pipe sections 1a, 2a of the tubes 1, 2 and the folded pipe sections 1b, 2b are joined by welding. The planes P1 and P2 shown in FIG. 1 are virtual planes.

As shown in FIGS. 1A and 1B, the first planar meandering tubes 1 are connected to each other by a communicating tube 1c, and the second planar meandering tubes 2 are also connected to each other by a communicating tube 2c. They are communicatively connected to form a series of tube units 3 and 4, respectively. The inlet of the tube unit 3 is indicated by 3 in and its outlet is indicated by 3 out, and the inlet of the tube unit 4 is indicated by 4 in and its outlet is indicated by 4 out.

Each straight pipe section 1 of the first plane meandering tube 1
a is the same as the outer diameter of each straight pipe portion 2a of the second planar meandering tube 2, and the distance between the axes of the straight pipe portions 1a, 1a of the first planar meandering tube 1, Distance between the meandering tubes 1 and 1 on one plane (interval between virtual planes P1 and P1)
And the interval between the straight pipe portions 2a of the second plane meandering tube 2 is the same.

FIG. 2 shows a tube unit 3 formed by arranging a plurality of first planar meandering tubes 1 in parallel at regular intervals as shown in FIG. 1A and connecting them to one another through a communication tube 1c. And a plurality of second planar meandering tubes 2
Each of the straight tube portions 2a of the second plane meandering tube 2 is connected to the first tube meandering tube 2 in a state where the second plane meandering tube 2 is orthogonal to the first plane meandering tube 1.
A tube unit combination body 5 composed of both tube units 3 and 4 is installed so as to be interposed in parallel between adjacent straight pipe portions 1a and 1a of the plane meandering tube 1.
Shows a state in which is formed. In FIG. 2, the second plane meandering tube 2 is indicated by a chain line in order to distinguish between the first plane meandering tube 1 and the second plane meandering tube 2.

FIG. 4 to FIG. 7 show two components as schematically shown in FIG.
FIG. 4 specifically shows a state in which a tube unit combination body 5 composed of two tube units 3 and 4 is arranged at a predetermined position in a heat exchanger body 6 to constitute a heat exchanger. FIG. 5 is a longitudinal sectional front view showing the front side of the tube unit combination body 5 in a state where the main body 6 is longitudinally cut. FIG. 5 is a cross-sectional plan view showing the upper surface side of the tube unit combination body 5 in a state in which the heat exchanger body 6 is crossed. FIG. 7 is a vertical sectional side view showing one side surface of the tube unit combination body 5 in a state where the heat exchanger body 6 is longitudinally cut, and FIG. 7 is a vertical sectional view of the tube unit combination body 5 taken along the arrow XX of FIG. 2 shows a surface structure.

One of the two tube units 3 and 4 forming the tube unit combination 5 is
The other unit 4 is a series of tubes in which a plurality of first planar meandering tubes 1 are arranged in parallel at regular intervals.
Is also composed of a plurality of second planar meandering tubes 2, and the second planar meandering tubes 2 are
Each straight pipe portion 2a of the second plane meandering tube 2 is perpendicular to the plane meandering tube 1
5 and 7 can be seen between the first flat meandering tubes 1 and 1 of one tube unit 3 which face each other by being installed so as to be interposed in parallel between the adjacent straight pipe portions 1a and 1a. So that the tube unit 3
Each of the space portions 7 is formed so as to face the first planar meandering tube 1 and the second planar meandering tube 2.

As described above, since the space portions 7 penetrating in the vertical direction of the tube unit 3 are formed between the first planar meandering tubes 1 and 1 facing each other in the tube unit 3, dust is formed in each space portion 7. Scraper 8 for removal
Can be inserted by vertically penetrating as shown in FIGS. Thus, each scraper 8 is moved by the scraper drive mechanism 9 to the first planar meandering tube 1 and the second planar meandering tube 1.
By reciprocating along the side surface of the plane meandering tube 2, dust attached to the outer surfaces of the straight pipe portions 1a and 2a forming the first plane meandering tube 1 and the second plane meandering tube 2, respectively, is effectively removed. can do.

Further, as described above, the first plane meandering tubes 1 are arranged in parallel at regular intervals, and the second plane meandering tubes 2 are arranged in a state perpendicular to the first plane meandering tubes 1. By incorporating each straight pipe portion 2a of the meandering tube 2 so as to be interposed in parallel between the adjacent straight pipe portions 1a, 1a of each first plane meandering tube 1, more tubes 1, 2 can be provided in a certain space. Can be effectively piped, whereby the heat transfer area of the tubes 1 and 2 can be made as wide as possible.

The heat exchanger body 6 comprises a furnace wall 10 on which bricks are stacked, and a heat insulating material layer 20 made of glass wool or the like is provided on at least inner surfaces of both ends of the furnace wall 10. In order to install the tube unit combination 5 in the heat exchanger body 6, the tube unit combination 5 is arranged in the heat exchanger body 6 in a state as shown in FIG. Combination body 5
Are supported on a support base 12 provided on the furnace wall 10 and the like, and as can be seen from FIGS. 4 and 5, the first plane meandering tube 1 and the second plane meandering tube 2 of the tube units 3 and 4. Both ends of each of the tubes 1 and 2 including the folded tube portion 1b of the (tube group) are embedded in the heat insulating material layer 20.

As shown in FIGS. 4 to 7, the scraper drive mechanism 9 includes a first and a second scraper 8 inserted into a space 7 formed between the first planar meandering tubes 1 and 1 facing each other. The reciprocating drive is performed along the side surfaces of the second plane meandering tubes 1 and 2, and two cranks 13 and 14 are respectively supported on the upper side and the lower side in the heat exchanger body 6, and the crank of the upper crank 13 is formed. A plurality of scrapers 8 are pivotally connected to the shaft 13a and the crankshaft 14a of the lower crank 14, and as shown in Fig. 6, the transmission means 1 transfers the support shaft 13b of the upper crank 13 and the support shaft 14b of the lower crank 14 to each other.
5, the supporting shafts 13b, 13b of both upper cranks 13, 13 are operatively connected by a transmission means 16, and the supporting shaft 14b of one lower crank 14 is transmitted by a motor 17, as shown in FIG. For example, by rotating alternately 180 degrees forward and reverse through
As shown in FIGS. 4 and 5, each scraper 8 is reciprocated along the side surfaces of the first and second plane meandering tubes 1 and 2 facing each space portion 7, whereby the first plane meandering tube 1 is moved.
And the straight pipe portion 1 forming the second planar meandering tube 2 respectively
The dust adhering to the outer surfaces of a and 2a is removed. It should be noted that the scraper drive mechanism 9 is merely an example, and other appropriate drive mechanisms can be employed.

FIGS. 8 and 9 show the first planar meandering tube 1.
Opposing straight pipe portions 1a, 1a, and these straight pipe portions 1a, 1a.
a of the second flat meandering tube 2 interposed between
And spacers 19 respectively inserted into gaps S between them. As can be seen from FIG. 9, each of the spacers 19 is formed in a concave curved shape such that both upper and lower ends can be fitted to the outer peripheral surfaces of the tubes 1 and 2. By using such a spacer 19, a difference in elongation due to thermal expansion between the tubes 1 and 2 can be absorbed, and damage to the tubes 1 and 2 can be prevented.

In the use of the heat exchanger having the above-described configuration, the high-temperature exhaust gas of, for example, 950.degree. C. discharged from the incinerator is placed inside the heat exchanger body 6 in the upper direction of FIGS. 4, 6, and 7, respectively. The water is supplied from the inlets 3in and 4in to the tube unit 3 composed of the first planar meandering tube 1 and the tube unit 4 composed of the second planar meandering tube 2, respectively. The water supplied to the tube unit 3 flows through the plurality of first plane meandering tubes 1, and the water supplied to the tube unit 4 also flows through the plurality of second plane meandering tubes 2.

In this way, the water is supplied to the first tube unit 3.
While flowing through the plane meandering tube 1 and the second plane meandering tube 2 of the tube unit 4, respectively, heat exchange is performed with the high-temperature exhaust gas flowing inside the heat exchanger body 6 to generate steam, and the steam is generated by the tube unit. Exit 3o for each of 3 and 4
It is discharged from ut, 4out. Although not shown, the discharged steam is supplied to, for example, a steam turbine via a steam pipe, and drives a turbine shaft to generate power.

In this heat exchanger, as can be seen from FIGS. 4 and 5, the first planar meandering tube 1 and the second planar meandering tube 2 of the tube units 3 and 4 (tube group).
Since both end portions of the tubes 1 and 2 including the folded tube portions 1b are embedded in the heat insulating material layer 20, the straight tube portions 1a and the folded tube portions 1b of the tubes 1 and 2 are formed.
Is welded by the high temperature of the high-temperature exhaust gas, and the welded portion is damaged due to the high heat of the high-temperature exhaust gas. You won't have to.

In the heat exchanger of the embodiment described above, a plurality of the first planar meandering tubes 1 are arranged in parallel at regular intervals and are connected to each other by the communication tube portion 1c, so that each tube 1 is continuously connected. A plurality of second plane meandering tubes 2 are similarly connected to each other by a communication tube portion 2c to form a tube unit 4 in which each tube 2 is continuous. Planar meandering tube 1 and each second planar meandering tube 2
Are not formed in such a unit, each tube 1, 2
May be independent.

In the heat exchanger of this embodiment, the first
Tube unit 3 composed of planar meandering tube 1 and tube unit 4 composed of second planar meandering tube 2
Although water is supplied from the respective inlets 3in and 4in to circulate, different fluids may be circulated through the tube units 3 and 4, respectively. For example, water flows through one tube unit 3 and alcohol flows through the other tube unit 4.

In this embodiment, the two fluids can be circulated by the two tube units 3 and 4. For example, a plurality of units composed of the first planar meandering tube 1 are formed, and the second planar meandering tube 2 is formed. If a plurality of units are formed, multi-fluid circulation can be performed. Further, in this embodiment, only one tube unit combination 5 is disposed in the heat exchanger main body 6, but such a tube unit combination 5 may be provided in a plurality of upper and lower stages.

According to the heat exchanger described above, as can be seen with reference to FIGS. 4 and 5, the heat insulating material layers 20 are provided on the inner surfaces of the left and right ends of the heat exchanger main body 6, and The furnace wall 10 is isolated and protected from the high-temperature exhaust gas by the heat insulating material layer 20, while the heat insulating material layer 20 is not disposed at the front and rear ends of the heat exchanger main body 6. Between the front and rear ends of the tube units 3 and 4 adjacent to the front and rear ends of the tube, that is, the first plane meandering tube 1 located at the front and rear ends, and the straight tube portions 1a and 1a vertically adjacent to the tube 1 Since the so-called membrane wall is formed by the straight pipe portion 1a of the second meandering tube 2, the furnace wall 10 is isolated and protected from the high-temperature exhaust gas at the front and rear ends of the heat exchanger body 6 by this membrane wall. Furnace wall 0 of service life can be extended.

FIGS. 10A and 10B show a first heat exchange tube of the heat exchanger shown in FIGS.
FIG. 2 shows a plane meandering tube 11 and a second plane meandering tube 22. Each of the tubes 11 and 22 is composed of a plurality of straight pipes 1a arranged in parallel at a predetermined interval in the same manner as the tubes 1 and 2, and It is formed so as to meander on a plane by the folded tube portion 1b connecting the adjacent end portions. The interval between the straight tube portions 2a of the second plane meandering tube 22 is the same as that of the first plane meandering tube 11. Same as the facing distance.

As shown in FIGS. 11 and 12, a plurality of the first planar meandering tubes 11 are arranged in parallel at regular intervals, and the second planar meandering tubes 22 are perpendicular to the first planar meandering tubes 11. And the second plane meandering tube 2
2 are installed so as to be interposed in parallel between adjacent straight pipe portions 1a, 1a of each first plane meandering tube 11, and the inlets 3in of each first plane meandering tube 11 are joined to a merging unit 23. , The outlets 3out are connected to each other by a merging unit 24, and the inlets 3in of the second meandering tubes 22 are connected to each other by a merging unit 25, and the outlets 3out are connected to each other by a merging unit 26. The body 27 is formed. The merging units 23 and 25 have fluid supply ports 23 respectively.
a, 25a, and the merging units 24, 26 are provided with fluid outlets 24a, 26a, respectively.

The tube assembly 27 formed as described above is installed at a predetermined position in the heat exchanger body as in the case of the above-described embodiment. In its use,
While the high-temperature exhaust gas is circulated inside the heat exchanger main body, the fluid supply ports 23a and 25a of the merging units 23 and 25 respectively.
Supply water respectively. The water supplied from the fluid supply ports 23a and 25a is supplied to the first planar meandering tube 11 and the second planar meandering tube 11, respectively.
The gas flows through the plane meandering tube 22 and exchanges heat with the high-temperature exhaust gas flowing through the heat exchanger body to generate steam during the flow, and the steam is generated at the fluid outlets 24 a and 24 of the merging units 24 and 26. It is discharged from 26a.

Also in this tube assembly 27, as shown in FIG. 12, a scraper 8 for removing dust is inserted into each space 7 formed between the opposing surfaces of each first planar meandering tube 11. Then, the scraper 8 is driven to reciprocate along the side surfaces of the first and second planar meandering tubes 11 and 22 facing each space portion 7 by the scraper driving mechanism 9 as described above.

[0032]

According to the heat exchanger of the first aspect of the present invention, a plurality of straight pipes arranged in parallel at regular intervals and a folded pipe connecting the adjacent ends of the straight pipes are flat. A plurality of first planar meandering tubes formed so as to meander above are arranged in parallel with each other at regular intervals, and a plurality of straight pipe portions arranged in parallel at intervals corresponding to the intervals between the first planar meandering tubes. A plurality of second plane meandering tubes formed so as to meander on a plane by a folded tube part connecting adjacent ends of the straight tube part are connected to each other in a state perpendicular to the first plane meandering tube. By assembling each straight pipe portion of the tube so as to be interposed in parallel between adjacent straight pipe portions of each first planar meandering tube, more and more flat meandering tubes can be effectively and compactly piped in a certain space. In Thereby the heat transfer area of the tube can take as wide as possible, thereby improving the heat exchange efficiency.

Also, with the above-described structure, since the space portions are formed between the first planar meandering tubes facing each other, a scraper for removing dust can be inserted into each space portion. Since the space is formed so as to face the first planar meandering tube and the second planar meandering tube, dust attached to the outer surfaces of the first planar meandering tube and the second planar meandering tube can be effectively removed. .

When the heat exchanger is used as a waste heat boiler of an incinerator, a tube assembly formed by combining a plurality of first plane meandering tubes and a plurality of second plane meandering tubes is used. At the side end, a so-called membrane wall is formed by the first plane meandering tube and the second plane meandering tube portion interposed between the straight pipes adjacent above and below the tube. The furnace wall of the main body is isolated and protected from high temperature exhaust gas, and the service life of the furnace wall can be extended. Further, each straight pipe portion of the second plane meandering tube is
Interposed between adjacent straight pipe sections of the first plane meandering tube in parallel
By incorporating it into the first planar meandering tube
The space formed between the opposing surfaces of the first planar meandering tube
A scraper for removing dust adhering to the tube
Is inserted into the first and the second by the scraper driving mechanism.
Reciprocating drive along the side of the second plane meandering tube
The first plane meandering tube and the second plane meandering tube.
Automatically removes dust adhering to the outside surface of the tube.
Can be.

According to a second aspect of the present invention, the first planar meandering tubes and the second planar meandering tubes may be connected to each other by a communicating pipe portion, respectively. Each of the entrances and exits of the first planar meandering tube and each of the entrances and exits of the second planar meandering tube may be connected and connected by a merging unit. You can choose either one like this,
It is possible to correspond to the heat transfer area of the fluid.

[0036]

As described in claim 4, the plurality of first plane meandering tube groups and the plurality of second plane meandering tube groups incorporated therein are disposed at predetermined positions in the heat exchanger body, By embedding both end portions of each tube including the folded tube portion in both tube groups in a heat insulating material layer arranged along the inner wall surface of the furnace wall of the heat exchanger main body, the incinerator is disposed inside the heat exchanger main body. When the high temperature exhaust gas from the tube is circulated, the joint between the straight pipe portion and the folded pipe portion of each tube by welding is cut off from the high temperature exhaust gas flowing outside each tube, and therefore, the welding of the joint portion The location is not damaged by melting due to high heat or transient thermal expansion.

[Brief description of the drawings]

FIGS. 1A and 1B show a plurality of first planar meandering tubes and second planar meandering tubes, each of which is a heat exchange tube of the heat exchanger shown in FIGS. FIG. 4 is a schematic perspective view showing a state in which the components are arranged at a position.

FIG. 2 is a schematic perspective view showing a tube unit combination of a tube unit composed of a first planar meandering tube and a tube unit composed of a second planar meandering tube.

FIG. 3A is an enlarged front view showing a first planar meandering tube, and FIG. 3B is an enlarged plan view showing a second planar meandering tube.

FIG. 4 is a vertical sectional front view of the heat exchanger in one embodiment of the present invention.

FIG. 5 is a cross-sectional plan view of the heat exchanger.

FIG. 6 is a vertical side view of the heat exchanger.

FIG. 7 is a sectional view taken along line XX of FIG. 5;

FIG. 8 shows a straight pipe portion of the first planar meandering tube,
It is explanatory drawing which shows the state which inserted the spacer in the clearance gap between the straight pipe part of the 2nd plane meandering tube interposed between these straight pipe parts, respectively.

FIG. 9 is an enlarged sectional view taken along line YY of FIG. 8;

FIG. 10 (A) shows a first embodiment according to another embodiment of the present invention.
FIG. 4B is a perspective view showing a planar meandering tube, and FIG. 4B is a perspective view showing a second planar meandering tube.

FIG. 11 is a perspective view of a tube assembly including the first and second planar meandering tubes shown in FIG. 10;

FIG. 12 is a longitudinal sectional view of the tube assembly shown in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 First meandering tube 1a Straight tube portion 1b Return tube portion 1c, 2c Communication tube portion 2 Second plane meandering tube 2a Straight tube portion 2b Return tube portion 3,4 Tube unit 1c, 2c Communication tube portion 3in, 4in Tube unit 3out, 4out Outlet of tube unit 6 Heat exchanger body 7 Space 8 Scraper 9 Scraper drive mechanism 10 Furnace wall of heat exchanger body 11 First meandering tube 22 Second meandering tube 23-26 Merging unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-71893 (JP, A) JP-A-62-248996 (JP, A) JP-A-11-148746 (JP, A) JP-A-11-148 294973 (JP, A) JP-A-11-270979 (JP, A) JP-A-53-69965 (JP, A) JP-A-63-161304 (JP, A) JP-A-47-6840 (JP, A) Japanese Utility Model Application No. Sho 60-32681 (JP, U) Japanese Utility Model Application Hei 5-66047 (JP, U) Japanese Utility Model Application No. 62-11876 (JP, U) Registered Utility Model 3050928 (JP, U) Japanese Utility Model Application No. 45-789 (JP) , Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F28D 1/047 F28F 1/00 F28G 1/08 F28D 1/047

Claims (4)

(57) [Claims] 1. A plurality of first pipes formed in a meandering manner on a plane by a plurality of straight pipes arranged in parallel at regular intervals and a folded pipe connecting adjacent ends of the straight pipes. A plurality of straight pipe portions are arranged in parallel with each other at a constant interval, and a plurality of straight pipe portions arranged in parallel at an interval corresponding to the interval between the first flat meander tubes, and adjacent ends of the straight pipe portions. A plurality of second plane meandering tubes formed so as to meander on a plane by a folded tube part connecting each other, each straight tube part of the second plane meandering tube in a state orthogonal to the first plane meandering tube. There viewing write so set as to be interposed in parallel between the straight pipe portion mutually adjacent a respective first plane serpentine tube, a second planar serpentine tubes that each straight pipe section each
Interposed between adjacent straight pipe sections of the first plane meandering tube in parallel
By incorporating it into the first planar meandering tube
The space formed between the opposing surfaces of the first planar meandering tube
A scraper for removing dust adhering to the tube
And insert the scraper into the first and second plane meandering channels.
A heat exchanger that is driven back and forth along the side of the tube . 2. The heat exchanger according to claim 1, wherein the first planar meandering tubes and the second planar meandering tubes are connected to each other by a communicating pipe portion. 3. The heat exchanger according to claim 1, wherein each of the entrances and exits of the first planar meandering tube and each of the entrances and exits of the second planar meandering tube are connected and connected by a merging unit. 4. A plurality of first plane meandering tube groups and a plurality of second plane meandering tube groups incorporated therein are disposed at predetermined positions in a heat exchanger body, and the folded tube portions in both tube groups are provided. The heat exchanger according to any one of claims 1 to 3, wherein both end portions of each of the tubes are embedded in a heat insulating material layer disposed along an inner surface of the furnace wall of the heat exchanger body.