JPS63116098A - Cross type heat exchanger - Google Patents

Abstract

PURPOSE:To enable a damage of a seal member not to cause a recessed deformation and further enable a superior sealing effect to be kept for a long period of time by a method wherein a seal member abutting against each of the corners of a unit is arranged in such a way as it may be moved only toward to or away from a center part of a unit plate and at the time a casing is provided with a seal member pressing means for pressing it toward the center of the unit plate. CONSTITUTION:Bolts 28 are arranged in radial directions with respect to center point of each of unit plates 12 and 15. Therefore, the bolts 28 are fastened to fasten springs 30, resulting in that seal members 24 are pressed toward central points of each of unit plates 12 and 15 through an abutting plate 26. A pressing force acting between each of seal members 24 and a recessed corner part 2 of each of unit plates 12 and 15 can be adjusted by adjusting an initial compressive stress by rotating the bolts 28. Therefore, a moving direction of the corner part of the unit plate and a moving direction of the seal member when the unit plate is thermally expanded or shrinked are coincided with each other and no relative movement is generated between the seal member and the corner part of the unit plate.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a gas and gas system that can be used as an air preheater for heating combustion air supplied to a combustion chamber of a boiler or the like with high-temperature exhaust gas. This relates to a cross-flow type heat exchanger for use.

(Prior art and its problems) As this type of cross-flow heat exchanger for gas, a set of two parallel sides of a rectangular plate are bent to one side, and a set of parallel sides of a rectangular plate is bent to one side. On the second side, a plurality of unit plates bent toward the other side are laminated so that the passage directions of the flow paths formed between adjacent unit plates change alternately by 90 degrees, and the two opposing sides Heat exchangers are known in which the edges are joined together to form a unit plate laminated unit, and this unit is housed in a casing, but in general, this type of heat exchanger suffers from fatigue failure at welded parts due to thermal expansion and contraction. Welding between the unit plates must be avoided in order to avoid such problems, or because the welding cost becomes very high when special materials such as titanium are used.

However, to connect the side edges of each unit plate, a fitting structure in which one side edge is sandwiched between the other side edge, or a curling structure in which both side edges are overlapped and rolled together can be adopted, but there are problems. The point lies in the sealing method between the unit plates at the corner portions of the unit plate stacked unit.

Conventionally, as in the heat exchanger described in JP-A-55-112990, for example, the corner portions of the unit plate laminated unit are loosely fitted into the corner recesses of the casing, and cast into the corner recesses of the casing. The unit corner portion was buried in the sealing material by filling it with a resin sealing material, thereby sealing between each unit plate in the unit corner portion. With the conventional method, it is not only difficult to completely fill the sealing filler into each corner recess of the casing without any gaps, but also the filling operation requires a lot of effort and time. There is also a drawback that replacement work due to deterioration or breakage of the filling requires a great deal of effort and time. Furthermore, in the method of using this casting type sealing filling, each unit plate of the unit moves relative to the sealing filling during thermal expansion and contraction, and the gap between the unit plate and the sealing filling increases. There was a risk that a gap would occur between the seals and the sealing effect would deteriorate.

(Means for Solving the Problems) The present invention proposes a cross-flow heat exchanger that can solve the conventional problems as described above, and its feature is that each of the four corners is cut out. A set of two parallel sides of a rectangular plate that was previously used is bent to one side, and the remaining set of two parallel sides are bent to the other side to form a plurality of unit plates into adjacent units. The unit plates are laminated so that the penetration directions of the flow paths formed between the plates change alternately by 90 degrees, and the opposing side edges are connected to each other to form a unit plate Mi layer unit. A cross-flow type heat exchanger installed in a casing having openings 2 & 11 communicating with each open end of the flow path of the system, wherein a sealing material abutting each corner of the unit is provided in the unit, The casing is arranged so as to be movable only in the far and near directions with respect to the center of the unit plate in the unit, and the casing is provided with a sealing material pressing means for pressing each of the sealing materials toward the center of the unit plate in the unit. It is in.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a rectangular plate with four corner parts 2 cut out in an arc shape, and a pair of parallel sides 3a and 3b are on one side. It has side edges 4a and 4b that are bent diagonally and extend parallel to the board surface, and the remaining pair of parallel sides 5a and 5b are bent obliquely to the other side and extend parallel to the board surface. It has side edges 6a and 6b extending in parallel. Further, a bending plate portion 7 is formed on the side edge of the arcuate corner portion 2 to be bent toward one side. Further, each side 3a,
A protruding portion 8 that protrudes to one side and has a height equal to the bending height of 3b, 5a, and 5b, and a protruding portion 9 that protrudes to the other side are formed at symmetrical positions vertically and laterally.

Once a plurality of rectangular plates 1 as described above are formed by press working, the side edges 4a and 4b of these rectangular plates 1 are folded back to one side to have a U-shaped cross section as shown in FIG. a square unit plate 12 having a mating side edge 10, and the side edges 6a, 6b cut to a width that can fit into the engaging side edge 10 to form a joined side edge 11; As shown in FIG. 4, the side edges 6a, 6b are folded back to the other side to form a U-shaped cross section to form an engagement side edge 13, and the side edge 4a,
4b, a plurality of square unit plates 15 are manufactured by cutting them to a width that can fit into the engaging side edge 13 to form the engaged side edge 14.

Next, as shown in FIG.
are slidably fitted in the longitudinal direction of the side edge, and the both wave engagement side edges 1 of the next unit plate 12 are fitted onto both engagement side edges 13 of the unit plate 15.
1 in the longitudinal direction of the side edge, that is, in a direction perpendicular to the sliding fitting direction of the previous unit plate 12. A plurality of unit plates 12 and 15 are alternately stacked so that they are slidably fitted. As a result, as shown in FIGS. 6 and 7, each corner portion 2 has a In this case, the bent plate portions 7 of the hundred unit plates 12 and 15 are adjacent to each other, and the protruding portions 8 are in contact with each other, and are connected by fitting the engaging side edge 13 and the engaged side edge 11. Between the adjacent unit plates 15 and 12, each corner portion 2 is open and the protruding portions 9 are in contact with each other.

As described above, the unit plate laminated unit 16 is constructed by laminating and integrating a plurality of unit plates 12 and 15, but as shown in FIG. Therefore, the unit plates 12.15 are arranged so that the protruding portions 9 face outward. Further, the unit plate 15 located at one end is a deformed unit in which a flat side edge 17, which is the same as the engaged side edge 14, is formed in place of the engaging side edge 13 having a U-shaped cross section and projecting outward. using a board. In the unit plate laminated unit 16 configured in this way, the protruding portions 9 are arranged between adjacent unit plates 12.15 where they are in contact with each other, and between the adjacent unit plates 12.15 where the protruding portions 8 are in contact with each other. , flow paths 18 and 19 are formed that penetrate in directions perpendicular to each other.

The unit plate laminated unit 16 described above is housed in a casing 20 as shown in FIGS. 8 to 10. This casing 20 has side plates 21 that abut against the protruding portions 9 and side edges 11.17 of the unit plates 12.15 located at both ends of the unit 16.
．． The inner ends of both side walls 22a and 22b of the connecting member 22 are attached to the unit plate laminated unit 16 as shown in the figure. The unit 16 is held at a predetermined position within the casing 20 near both ends of each side of the casing 20 .

In the sealing material holding space 23 formed between the side walls 228.22b of the connecting member 22, each unit plate 12.15 is provided.
A sealing material 24 that continues in the stacking direction and presses against the bent plate portion 7 of each arc-shaped corner portion 2 of each unit plate 12.15 is provided inside. This sealing material 24 is also in pressure contact with both side wall portions 22a and 22b of the connecting member 22 and both side plates 21 of the casing 20. 25
is a sealing material pressing means, which includes a patch plate 26 that contacts the back surface of the sealing material 24, spring positioning bolts 27 protruding from a plurality of locations in the length direction of the patch plate 26, and opposing bolts 27. A plurality of spring pressing bolts 28 are screwed through screw holes of a bridging member 22C provided in the connecting member 22, and loosely fit between the inner ends of the bolts 28 and the bolts 27. The spring receiver screwed onto the inner end includes a compression coil spring 30 interposed between the nut 29 and the back surface of the light plate 26, and a locking nut 31 for fixing the bolt 28.
It consists of

Each of the sealing materials 24 is attached to both side wall portions 22a of the connecting member 22.
, 22b, each unit plate 12.15 in the unit plate laminated unit 16 is supported so as to be movable only in the far and near radial direction, and the bolt 2
8 is arranged in the near and far radial direction with respect to the center of each unit plate 12.15. Therefore, when the bolt 28 is tightened to compress the spring 30, the sealing material 24 is pressed toward the center of each unit plate 12, 15 via the backing plate 26. The pressing force between each sealing material 24 and the notched corner portion 2 of each unit plate 12.15 can be arbitrarily adjusted by rotating the bolt 28 and adjusting the initial compressive stress of the spring 30.

32a, 32b and 33a, 33b are two adjacent
The openings 32a and 32b are connected to both ends of the flow path 18 in the unit plate stacking unit 16, and the openings 32a and 32b are surrounded by two connecting members 22 and both side plates 21.
33 and 33b communicate with both ends of the flow path 19. Around each of these openings 32a to 33b, there is provided a duct connection device consisting of a flange portion 34 continuous from the both side plates 21 and a flange 35 portion formed on both side walls 22a, 22b of the connecting member 22. A flange 36 is provided.

In the cross-flow heat exchanger configured as described above, the two mutually orthogonal flow paths 18 and 19 in the unit plate laminated unit 16 are connected only through the casing openings 322 to 33b connected to both ends, respectively. It communicates with the outside world, and the arcuate cutout corner part 2 is illuminated to communicate with the outside world and the other flow path.
! ! This is prevented by a sealing material 24 that is in pressure contact with the corner portion 2. Of course, this sealing material 24 blocks the adjacent openings 32a to 33b, and prevents, for example, the opening 32a from communicating with the adjacent openings 33a and 33b. Therefore, for example, from the opening 32a to the opening via the wave path 18 of the unit plate stacking unit 16! A duct connection flange 36 is provided at each of the openings 328 to 33b so that high temperature exhaust gas flows to the opening 2b, and combustion air flows from the opening 33a to the opening 33b via the flow path 19 of the unit 16. By connecting a predetermined duct through the heat exchanger, the high temperature exhaust gas flowing in the flow aia and the flow path 18 are perpendicular to each other, without mixing the exhaust gas and combustion air in the heat exchanger. Channel 19
It is possible to preheat the combustion air by exchanging heat with the combustion air flowing therethrough through the unit plate 12.15 between both flow paths 18.19.

Note that the bent plate portions 7 at the notched corner portions 2 of each unit plate 12.15 are effective for preventing the sealing material 24 from digging in, but are not essential to the present invention. The protrusions 8 and 9 that regulate the flow path between adjacent unit plates 12 and 15 are also not essential to the present invention and may be omitted depending on the case.
A sealing member 2 for sealing the cutout corner portion 2 between the adjacent unit plates 12゜15 is used as a sealing means for sealing between the space b.
4 is also used, but it is also possible to separately provide a sealing means for sealing between the adjacent openings 323 to 33b and a sealing material for sealing the cutout corner portion 2 between the adjacent unit plates 12 and 15. Further, the cross-sectional shape of the sealing material 24 and the structure of the sealing material pressing means are not limited to those shown in the embodiments. For example, when the backing plate 26 is used in combination, a sheet-shaped sealing material can also be used.

Even if there is some gap between the side edges 10, 14 and 11.13 that fit into each other between adjacent unit plates 12.15, when used as an air preheater, the amount of exhaust gas leakage will be zero. There is no practical problem because it is permissible within .5% and the combustion air pressure is usually set slightly higher than the exhaust gas pressure, but if necessary, the side edges that fit together It is also possible to pass the parts 10, 14 and 11.13 through a pressure forming roller and press them together, or it is also possible to join them by a curling structure in which both side edges are rolled over each other.

(Operations and Effects of the Invention) As described above, according to the cross-flow heat exchanger of the present invention, the distance between adjacent unit plates in a unit plate stacked unit configured by integrating a plurality of unit plates into one layer is Each cutout corner is configured to be sealed with a sealing material that presses against the corner, so compared to the conventional structure in which a cast-type sealing filler is used to seal the corner, it is easier to assemble. This can be done easily and the sealing material can be replaced easily. Moreover, it is possible to use a sealing material that is cheaper and has a longer service life than a cast-type sealing filler, and it is possible to reduce the cost of the entire heat exchanger.

Further, according to the present invention, the sealing material is disposed so as to be movable only in the direction of distance with respect to the center of the unit plate in the unit, and the sealing material pressing means on the casing side pushes each of the sealing materials into the unit. Since the unit is configured to be pressed toward the center of the unit plate in the casing, the unit is not only stably positioned at a predetermined position within the casing via the sealing material at each corner and the sealing material pressing means, but also When the unit plate thermally expands and contracts, the moving direction of the unit plate corner portion matches the moving direction of the sealing material, and the sealing material and the unit plate corner are pressed against the unit plate corner portion by the sealing material pressing means. Therefore, not only will there be no gap between the sealing material and the corner of the unit plate due to thermal contraction of the unit plate, but also the seal There is no fear that the sealing material will be damaged or deformed due to relative movement between the material and the corner portion of the unit plate, and the reliable sealing effect of the sealing material can be maintained well for a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a rectangular plate for configuring a unit plate;
Figure 2 is a vertical side view of the unit plate, Figures 3 and 4 are front views of the molded unit plates, Figure 5 is a front view illustrating how to connect the unit plates, and Figure 6 is the assembled unit plate. FIG. 7 is a partially cutaway side view of the unit; FIG. 8 is a partially omitted longitudinal sectional front view of a heat exchanger assembled using the unit; FIG. The figure is a plan view of the heat exchanger, and FIG. 10 is a cross-sectional plan view of the main parts of the heat exchanger. 1... Rectangular plate, 2... Arc-shaped notch corner part,
3a, 3b, 5a, 5b... diagonally bent sides,
7...Bending plate part, 8,9...Protruding part, 10.13.
... Engagement side edge with U-shaped cross section, 11.14... Engagement side edge, 12.15... Unit plate, 16... Unit plate laminated unit, 18.19... Mutual Two orthogonal flow paths, 20 river casing, 22... connecting member, 24...
-Sealing material, 25...Sealing material pressing means, 26...
Temporary stopper, 27...Spring positioning bolt, 28
... Spring pressing bolt, 3o... Compression coil spring, 32a-33b... Opening.

Claims (1)

[Claims] A pair of parallel 2 sides of a rectangular plate with four corners cut out are bent to one side, and a pair of parallel 2 sides left.
The side edges are formed by stacking a plurality of unit plates bent toward the other side so that the passing directions of the flow paths formed between adjacent unit plates alternate by 90 degrees, and the opposing side edges A cross-flow type heat exchanger in which the unit plates are connected to each other to form a unit plate laminated unit, and this unit plate laminated unit is housed in a casing provided with two sets of openings communicating with each open end of the two channels. In the casing, sealing materials abutting each corner of the unit are disposed so as to be movable only in the far and near directions with respect to the center of the unit plate in the unit, and each of the sealing materials is disposed in the casing. A cross-flow type heat exchanger comprising a sealing material pressing means for pressing toward the center of a unit plate in the unit.