JPH0450520B2 - - Google Patents

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 penetration direction of the flow path formed between adjacent unit plates changes alternately by 90 degrees, and the two opposing sides The edges are joined together to form a unit plate laminated unit,
Heat exchangers with this unit built into a casing are known, but generally, in this type of heat exchanger,
Welding between the unit plates must be avoided in order to avoid fatigue failure of the welded parts due to thermal expansion and contraction, or if special materials such as titanium are used, welding costs can be extremely high. It won't happen.

However, to connect the side edges of each unit plate,
It is possible to adopt 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 up, but the problem is that the unit at the corner of the unit plate laminated unit It's in the sealing method between the plates.

Conventionally, as in the heat exchanger described in Japanese Patent Application Laid-Open No. 55-112990, the corner portion of the unit plate laminated unit is loosely fitted into the corner recess of the casing, and the heat exchanger is cast into the corner recess 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. In 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 great deal of effort and time. There was also a drawback that replacement work due to deterioration or damage of the filler required a great deal of effort and time. Furthermore, in this method of using a cast-type sealing filler, each unit plate of the unit moves relative to the sealing filler during thermal expansion and contraction, and the gap between the unit plate and the sealing filler 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 above-mentioned conventional problems, 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 plates are laminated so that the passage directions of the flow channels formed between the plates change alternately by 90 degrees, and the opposing side edges are connected to each other to form a unit plate stack unit, and this unit plate stack unit is combined into two systems. A cross-flow type heat exchanger installed in a casing having two sets of openings communicating with each opening end of the flow path, which are continuous in the stacking direction of the unit plates and have the same shape as the corner part of the unit plates. A sealing material pre-formed into a shape having a cross section is placed in contact with each corner of the unit 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 casing is provided with each of the sealing materials. The present invention is characterized in that a sealing material pressing means is provided for pressing the sealing material toward the center of the unit plate in the unit.

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

In Figures 1 and 2, 1 is a rectangular plate with four corner parts 2 cut out in an arc shape, and a pair of parallel sides 3a, 3b are diagonal to one side. The remaining two parallel sides 5a, 5b are bent obliquely to the other side and are parallel to the plate surface. It has side edge portions 6a and 6b that extend to.
Further, a bending plate portion 7 is formed on the side edge of each arcuate corner portion 2 to be bent toward one side. Furthermore, in the square flat plate part surrounded by each corner part 2,
A protrusion 8 protruding to one side having a height equal to the bending height of each of the sides 3a, 3b, 5a, 5b and a protrusion 9 protruding to the other side are formed in symmetrical positions vertically and horizontally, respectively. has been done.

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. The side edges 6a and 6b are the engaging side edge 10.
A square unit plate 12 is cut to a width that can fit into the engaged side edge 11, and the side edges 6a, 6b are folded back to the other side to have a U-shaped cross section as shown in FIG. A square unit plate 15 is formed by cutting the side edges 4a and 4b into a width that can fit into the engaging side edge 13 to form the engaged side edge 14. A plurality of each of these are manufactured.

Next, as shown in FIG. 5, both engaged side edges 14 of the turned unit plate 15 are slidably fitted onto both engaging side edges 10 of the unit plate 12 in the longitudinal direction of the side edges. Then, the both engaged side edges 11 of the next unit plate 12 are fitted onto both engaging side edges 13 of the unit plate 15 in the longitudinal direction of the side edges, that is, the previous unit plates 12 and 15 are slidably fitted. A plurality of unit plates 12 and 15 are alternately laminated so that they are slidably fitted in a direction perpendicular to the mating direction, and then the unit plate 15 turned over is slidably fitted to the unit plate 12 as described above. do. As a result, as shown in FIGS. 6 and 7, between the adjacent unit plates 12 and 15 connected by the engagement side edge 10 and the engaged side edge 14, each corner 2 At both unit plates 12,1
Adjacent unit plates 15, in which the bent plate portions 7 of No. 5 are adjacent to each other and the protruding portions 8 are opposed to each other, and are connected by fitting between the engaging side edge 13 and the engaged side edge 11, 12, each corner portion 2 is open and the protruding portions 9 are in contact with each other.

As described above, a plurality of unit plates 12 and 15 are laminated and integrated to constitute the unit plate laminated unit 16, but as shown in FIG.
The unit plates 12 and 15 are arranged so that the bent plate portions 7 of the unit plates face inward and the protruding portions 9 face outward. Furthermore, the unit plate 15 located at one end has an engaging side edge 1 having a U-shaped cross section and projecting outward.
3, a deformable unit plate is used in which a flat side edge 17 which is the same as the engaged side edge 14 is formed. Unit plate laminated unit 1 configured in this way
In No. 6, a channel is provided that penetrates in directions orthogonal to each other between adjacent unit plates 12 and 15 where the protruding portion 9 is in contact with each other and between adjacent unit plates 12 and 15 where the protruding portion 8 is in contact with each other. 18 and 19 are formed.

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, respectively. The inner ends of both side wall portions 22a and 22b of the connecting member 22 are connected to each other at the four corners corresponding to the corner portions 2 of the unit plate stacking unit 16, as shown in the figure. Close to both ends of each side, the unit 16 is attached to the casing 2.
It is held at a predetermined position within 0.

In the sealing material holding space 23 formed between the side walls 22a and 22b of the connecting member 22, the circular arc in each unit plate 12 and 15 is continuous in the stacking direction of each unit plate 12 and 15. A sealing material 24 that presses against the bent plate portion 7 of each corner portion 2 of the shape is installed inside. This sealing material 24 also applies to the connecting member 22.
It is also in pressure contact with both side walls 22a, 22b and both side plates 21 of the casing 20. 25
is a sealing material pressing means, and the sealing material 24
a backing plate 26 that abuts the back surface of the backing plate 26; spring positioning bolts 27 protruding from multiple locations in the length direction of the backing plate 26; and a bridging member 22 provided on the connecting member 22 so as to face each of the bolts 27.
A plurality of spring pressing bolts 28 screwed through the screw holes c, and a spring receiver loosely fitted between the inner end of the bolt 28 and the bolt 27 and screwed into the inner end of the bolt 28. It consists of a compression coil spring 30 interposed between the nut 29 and the back surface of the backing plate 26, and a lock nut 31 for fixing the bolt 28.

Each of the sealing materials 24 is guided by both side walls 22a and 22b of the connecting member 22, so that each of the unit plates 12 and 1 in the unit plate laminated unit 16 is
The bolts 28 are supported so as to be movable only in the near and far reflection direction with respect to the center of the unit plate 1.
2 and 15 in the far-reflection direction. Therefore, when the bolt 28 is tightened to compress the spring 30, the sealing material 24 is pressed toward the center of each of the unit plates 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 is controlled by rotating the bolt 28 and applying pressure to the spring 3.
It can be arbitrarily adjusted by adjusting the initial compressive stress of 0.

32a, 32b and 33a, 33b are openings surrounded by two adjacent connecting members 22 and both side plates 21, respectively.
b is the flow path 1 in the unit plate laminated unit 16.
The openings 33a and 33b communicate with both ends of the flow path 19. Each of these openings 32
Around a to 33b, there are flange portions 34 connected from the both side plates 21 and flanges 35 formed on both side wall portions 22a and 22b of the connecting member 22.
A duct connection flange 36 is provided.

In the cross-flow heat exchanger constructed 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 32a to 33b connected to both ends, respectively. Communication with the outside world and communication with the outside world or the other flow path through the arc-shaped cutout corner portion 2 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 and 33b, and prevents, for example, the opening 32a from communicating with the adjacent openings 33a and 33b. Therefore, for example, high-temperature exhaust gas flows from the opening 32a to the opening 32b via the flow path 18 of the unit plate stack unit 16,
A predetermined duct is connected to each opening 32a to 33b via a duct connection flange 36 so that combustion air flows from the opening 33a to the opening 33b via the flow path 19 of the unit 16. Therefore, the high-temperature exhaust gas flowing through the flow path 18 and the combustion air flowing through the flow path 19 which is orthogonal to the flow path 18 without mixing exhaust gas and combustion air in this heat exchanger. The combustion air can be preheated by exchanging heat with the combustion air through the unit plates 12, 15 between the flow paths 18, 19.

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. In addition, adjacent unit plates 12,1
The protruding portions 8 and 9 that regulate the width of the flow path between the tubes 5 and 5 are also not essential to the present invention, and may be omitted as the case may be. Furthermore, adjacent unit plates 12,
Although the sealing material 24 is also used to seal the notch corner portion 2 between the openings 32a and 15, the adjacent opening 32a
It is also possible to separately provide a sealing means for sealing between the parts 1 to 33b and a sealing material for sealing the cutout corner part 2 between the adjacent unit plates 12 and 15.
Furthermore, the cross-sectional shape of the sealing material 24 and the configuration of the sealing material pressing means are not limited to those shown in the embodiments. For example, when using the patch plate 26 together, 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 the adjacent unit plates 12, 15, when used as an air preheater, the amount of exhaust gas leakage is 0.5. % or less, and the combustion air pressure is normally set slightly higher than the exhaust gas pressure, there is no practical problem, but if necessary, the side edges that fit together may be It is also possible to press 10, 14 and 11, 13 through a pressure forming roller,
It is also possible to join by a curling structure in which both side edge portions are overlapped and rolled up.

(Operations and Effects of the Invention) As described above, according to the cross-flow heat exchanger of the present invention, each unit plate between adjacent unit plates in a unit plate laminated unit configured by laminating and integrating a plurality of unit plates. Since the cutout corner is configured to be sealed with a sealing material that presses against the corner, assembly is easier than with a conventional structure in which a cast-type sealing filler is used to seal the corner. It's easy to do, and the sealing material can be easily replaced. 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. There is no relative movement between the two parts. Therefore, not only will there be no gap between the sealing material and the corner portion of the unit plate due to thermal contraction of the unit plate, but also the relative movement between the sealing material and the corner portion of the unit plate will cause the sealing material to There is no fear that the seal will be damaged or deformed, and the reliable sealing effect of the sealing material can be maintained well over a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a rectangular plate for constructing a unit plate, Fig. 2 is a vertical side view thereof, Figs. 3 and 4 are front views of the formed unit plate, and Fig. 5 is a unit plate. Fig. 6 is a perspective view showing the corner of the assembled unit plate laminated unit, Fig. 7 is a partially cutaway side view of the same unit, and Fig. 8 is a diagram showing the use of the unit. FIG. 9 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 cutout corner portion, 3a, 3b, 5a, 5b... diagonally bent side, 7... bent plate portion, 8, 9... protruding curve Part 1
0,13... Engagement side edge with U-shaped cross section, 11,1
4... Engaged side edge, 12, 15... Unit plate, 1
6... Unit plate laminated unit, 18, 19... Two mutually orthogonal channels, 20... Casing, 2
2... Connecting member, 24... Sealing material, 25... Sealing material pressing means, 26... Backing plate, 27... Spring positioning bolt, 28... Spring pressing bolt, 30... Compression coil spring, 3
2a to 33b...openings.

Claims (1)

[Claims] 1 A plurality of rectangular plates with four corners cut out, a set of two parallel sides bent in one direction, and the remaining set of two parallel sides bent in the other side. unit plates are stacked such that the passing directions of the flow paths formed between adjacent unit plates alternate by 90 degrees, and the opposing side edges are connected to each other to form a unit plate stacked unit, This unit plate laminated unit is housed in a casing having two sets of openings that communicate with each opening end of the two channels, and the units are continuous in the stacking direction of the unit plates. A sealing material pre-formed in a shape having a cross section of the same shape as the corner portion of the plate is placed in contact with each corner portion of the unit so as to be movable only in the direction of distance with respect to the center of the unit plate in the unit. . A cross-flow type heat exchanger, wherein the casing is provided with sealing material pressing means for pressing each of the sealing materials toward the center of the unit plate in the unit.