JPH0587756B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a corrugated ceramic heat transfer block for an orthogonal heat exchanger.

[Conventional technology]

Conventionally, orthogonal heat exchangers using corrugated ceramic heat transfer blocks have been used.
As shown in the figure, a heat transfer element 10 is constituted by a ceramic corrugated plate 11 made of inorganic fibers and a ceramic flat plate 12 in contact with the corrugated plate 11. As shown in FIG. 5, a heat transfer block 2 is constructed by stacking a plurality of heat transfer elements 10 alternately so that the corrugated directions of the corrugated plates 11 are orthogonal to each other.
0 is formed. Two types of fluids having different temperatures pass through the heat transfer block 20 in the directions indicated by arrows A and B and exchange heat with each other.

FIG. 6 shows an example of an orthogonal heat exchanger 30 constructed by combining and tightening a plurality of heat transfer blocks 20 in consideration of the flow rate of fluid passing through the blocks and allowable pressure loss. . Here, for example, high-temperature combustion exhaust gas passes through the heat exchanger 30 from top to bottom as indicated by arrows E and E', while low-temperature air passes as indicated by arrows C ₁ , C ₂ , C ₃ , and C ₄ The light passes through the heat exchanger 30 in the horizontal direction, and heat exchange is performed between the two.

When this orthogonal heat exchanger 30 is used to exchange heat between the combustion exhaust gas E and the combustion air C, the combustion exhaust gas E is sequentially cooled down as a result of the heat exchange, and soot in the combustion exhaust gas E is reduced in the areas below the acid dew point. Adheres to heat transfer surfaces. As soot accumulates over time and reduces the amount of heat transfer, soot blowing (hereinafter referred to as suit blowing) is performed from the inlet or outlet of the combustion exhaust gas E, or from both the inlet and outlet, to remove the attached soot. conduct. As shown in FIG. 7, cold water, hot water, hot water, steam, etc. are appropriately selected and used as the suit blow fluid J ejected from the suit blow pipe 21, but the soot removal effect is different from the suit blow fluid J. This is achieved by two factors; the exfoliation effect due to the temperature difference between the soot and the heat transfer surface, and the exfoliation effect due to the impact force when the pressurized suit blowing fluid J is ejected from the pores and collides with the soot; the former. It is generally believed that the peeling effect is determined by the type of fluid, and the latter by the original pressure and density of the fluid.

In FIG. 6, when loading the heat transfer block 20 into the casing 22, a heat transfer block presser 23 is used at the corner of the heat transfer block 20, but there is no packing between the heat transfer block 20 and the heat transfer block presser 23. 23a is inserted.

[Problem that the invention seeks to solve]

The corrugated plate 11 and flat plate 12 of the heat transfer element 10 explained in FIG. 4 are made of ceramic paper with a thickness of about 1 mm, and as shown in FIG.
Squirt out suit blow fluid J, 0.5 to 0.7 g/cm ²
When a suit blow impact force of
A through hole 11c is formed in the upper end 11a of 1, from which combustion air leaks, making it impossible to exchange heat.
The equipment as a heat exchanger will be damaged.

On the other hand, in FIG. 6, only the end 20a of the heat transfer block 20 contacts the packing 23a, so the tightening force is concentrated there, causing the end of the ceramic paper to break or the corrugated plate to be crushed, resulting in poor sealing performance. be damaged. To prevent this,
If a soft material made of bundles of glass wool or ceramic paper is used as the packing 23a, the end 20a of the heat transfer block 20 will be hugged and the contact area will be wide, so the concentration of tightening force will be eased and the end of the ceramic paper Although this solves the problem of breakage and crushing, the sealing performance is eventually impaired because exhaust gas and combustion air pass through the inside of the packing material.

An object of the present invention is to overcome the above-mentioned conventional drawbacks and provide a heat transfer block for an orthogonal heat exchanger in which the corrugated plates are not damaged even when subjected to repeated suit blow impact forces. In the present invention, when loading the heat transfer block into the casing,
It is an object of the present invention to provide a heat transfer block for an orthogonal heat exchanger which has good packing contact by dispersing the tightening force at the part of the heat transfer block that comes into contact with the packing.

[Means for solving problems]

In order to achieve the above object, the present invention provides an orthogonal type heat transfer element in which a plurality of heat transfer elements each consisting of ceramic corrugated plates and flat plates made of inorganic fiber paper are laminated such that the corrugated directions of the corrugated plates are orthogonal to each other. In a heat transfer block for a heat exchanger, ceramic solid is applied to all recesses formed between the corrugated plate and the flat plate on the side where suit blowing is performed to remove soot adhering to the heat transfer surface of the heat transfer block. It is characterized by being filled.

Further, in a heat transfer block for an orthogonal heat exchanger, a plurality of heat transfer elements each consisting of ceramic corrugated plates and flat plates made of inorganic fiber paper are laminated such that the directions of the corrugations of the corrugated plates are orthogonal to each other, All the recesses formed by the corrugated plate and the flat plate on the side where suit blowing is performed to remove soot adhering to the heat transfer surface of the heat transfer block, and when loading the heat transfer block into the casing. The structure may be characterized in that a recess, rather than the corrugated plate and the flat plate, which is in contact with the gasket attached to the corrugated plate is filled with ceramic solid.

[Effect]

In the present invention configured as described above, all the recesses formed by the corrugated plate and the flat plate on the side of the heat transfer block where suit blowing is performed are filled with ceramic solid. The plates and flat plates are strengthened and the corrugated plates and flat plates are protected from the impact force of the suit blow. In addition to this, the recess formed by the corrugated plate and the flat plate where the packing comes into contact is also filled with ceramic solid.
When the heat transfer block is loaded into the casing and tightened, the tightening force is dispersed, preventing damage to the heat transfer block.

Ceramic solids are required to have the following performance. In other words, it has water resistance, acid resistance, heat resistance, impact resistance against suit blowing, thermal shock resistance, adhesion with the heat transfer block body when filled into a narrow gap, and resistance to shrinkage due to heating. .

In the present invention, the ceramic solid is not particularly limited as long as it satisfies the above-mentioned required performance, but for example, a mixture of a binder, an aggregate, a reinforcing fiber, and a thickener is preferable.

That is, the binder is used for bonding other materials and for adhesion to the wall, and preferred are silica binders such as silica gel, ethylene silicate, and alkali silicate, alumina sol, aluminum phosphate, and the like.

Aggregate is added for suit blow resistance, sealing properties, etc., and commonly used inorganic powders such as calcium carbonate and clay can be used, but if acid resistance is particularly required, silica and amorphous powders can be used. Preferable examples include silicic acid powder such as silica, C glass flakes, mica, titanium oxide, and zirconia powder.

Reinforcing fibers are used for heat shrinkage resistance and thermal shock resistance, such as E-glass fibers, potassium titanate fibers,
Inorganic fibers of wollastonite can be used, and in particular when acid resistance is required, C glass fibers, silica glass fibers, and alkali-resistant glass fibers are preferred.

In addition, thickeners are added for the purpose of preventing separation of binder and aggregate, and preventing sagging after filling.
Organic materials such as methyl cellulose, carboxymethyl cellulose, polyethylene oxide, and sodium alginate, and inorganic materials such as bentonite and clay are preferred.

〔Example〕

Next, the present invention will be described by way of examples with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the present invention, in which a ceramic corrugated plate 1 and a flat plate 12 of a heat transfer element 10 in the present invention are substantially the same as those explained in FIG. heat block 2
The arrangement of the heat transfer elements 10 at 0 is also substantially the same as that explained in FIG. 5, so its explanation is omitted. In the present invention, all the recesses formed by the corrugated plate 11 and the flat plate 12 in the upper part of the heat transfer element 10, which is the side where soot blowing is performed, are filled with ceramic solid 13. In this case, when the heat transfer element 10 is manufactured, the ceramic solid 13 is filled and fired. This configuration protects the corrugate plate 11 from the suit blowing impact force generated during suit blowing. As a result, even if an impact force of 0.5 to 0.7 g/cm ² was applied 2000 times, there was no damage to the corrugated board 11 facing the impact. As a result, it has become possible to perform a more powerful suit blow by increasing the original pressure of the fluid. It is preferable that the filled portion of the ceramic solid 13 has a gently convex shape with a semi-cylindrical roof or an isosceles triangular shape with a low height, and protrudes from the end of the heat transfer element 10.

2 and 3 are perspective views of other embodiments of the invention. Heat transfer block 2 in this example
0. The structures of the heat transfer element 10, the corrugated plate 11, and the flat plate 12 are substantially the same as those explained in FIGS. 1 and 5, so the explanation will be omitted. Also the 6th
Heat transfer block holder 23 similar to that explained in the figure
are attached to the corners of the heat transfer blocks 20 via packings 23a, and the plurality of heat transfer blocks 20 are loaded into the casing in the same manner as shown in FIG. In this embodiment, in addition to the recesses shown in FIG. Solid 14 is filled. In this case, the ceramic solid 14 is filled and fired when the heat transfer element 10 is manufactured. This prevents damage to the corrugated plate 11 due to suit blowing, eliminates concentration of tightening force on the edges of the ceramic paper, and eliminates breakage of the edges of the corrugated plate 11 and flat plate 12 with the same tightening force. did.

In order to cover the surface roughness of the filled ceramic solid 14, the packing 23a used here is made of a foamed fluoro rubber sheet or the like having single cells with a porosity of 60 to 70% with a tightening force of 1.5 kgf/cm ² . It is desirable to use

Next, more specific examples of the heat transfer block of the present invention will be described.

An inorganic fiber paper with a weight of 120 g/m ² and a thickness of 1 mm is made by a conventional method from zirconium-containing glass (generally known as alkali-resistant glass, ARG) fibers and a polyvinyl alcohol resin binder. 300g/cm ² of silica powder was applied to the surface.
This inorganic fiber paper is used to perform normal corrugation processing, and the direction of the corrugation (fluid passage direction) is
After laminating and adhering by alternating 90 degrees, impregnating with hardening material liquid (binder: colloidal silica, aggregate: silica powder, C glass flakes), drying and hardening.
Repeat the firing process 3 times to make a 300mm square (300 x 300
×300mm) orthogonal ceramic heat transfer blocks were fabricated.

This block has a wall thickness of 1.1 mm and a plate height of 9
mm, pitch 15mm, and density 400Kg/ ^m3 .

Next, ceramic solid (binding material:
Colloidal silica, aggregate: silica powder, white carbon, thickener: methyl cellulose) were filled into a gently convex shape similar to the roof of a kamaboko, then dried, hardened, and fired.

A plurality of blocks were prepared in this way, and a foamed fluoro rubber sheet (density 0.4 g/cm ³ ) having a width of 20 mm and a thickness of 5 mm was applied as a packing material to the corner of each block, and the blocks were loaded into a casing. The block was tightened from the outside of the casing so that a surface pressure of 1 kgf/cm ² was applied to the packing material.

The suit blow test and leaf test results of this heat transfer block were significantly superior to conventional ones. In addition, the following can also be carried out to produce a heat transfer block.

That is, (a) When the zirconia-containing glass fiber is used as C glass fiber.

(b) The block of the example was further treated with a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin (to prevent dust adhesion).

〔Effect of the invention〕

According to the present invention, by filling all the recesses formed by the corrugated plate and flat plate on the side of the heat transfer block where suit blowing is performed with ceramic solid, the corrugated plate and flat plate made of inorganic fiber paper can be suit-blown. Can be protected from blow impact force. Furthermore, by filling the recess formed by the corrugated plate and the flat plate where the packing comes into contact with ceramic solid, the tightening force is dispersed when the heat transfer block is loaded into the casing and tightened. Damage to the thermal block can also be prevented.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of one embodiment of the present invention, Fig. 2 is a perspective view of another embodiment of the invention, Fig. 3 is a partially removed perspective view of Fig. 2, and Fig. 4 is a corrugated ceramic structure. A perspective view of a thermal element, FIG. 5 is a perspective view of a conventional heat transfer block, FIG. 6 is a front view of an orthogonal heat exchanger, and FIG. 7 is a perspective view of a conventional heat transfer block for explaining the suit blowing operation. It is a diagram. 10... Heat transfer element, 11... Corrugated plate,
12... Flat plate, 13, 14... Ceramic solid,
20...Heat transfer block, 23...Packing holder, 23
a...Patsukin.

Claims (1)

[Claims] 1. For an orthogonal heat exchanger in which a plurality of heat transfer elements each consisting of ceramic corrugated plates and flat plates made of inorganic fiber paper are stacked such that the directions of the corrugations of the corrugated plates are orthogonal to each other. In the heat transfer block, all the recesses formed by the corrugated plate and the flat plate on the side where suit blowing is performed to remove soot adhering to the heat transfer surface of the heat transfer block are filled with ceramic solid. A heat transfer block for an orthogonal heat exchanger. 2. A heat transfer block for an orthogonal heat exchanger in which a plurality of heat transfer elements each consisting of ceramic corrugated plates and flat plates made of inorganic fiber paper are laminated such that the directions of the corrugations of the corrugated plates are orthogonal to each other, All the recesses formed by the corrugated plate and the flat plate on the side where suit blowing is performed to remove soot adhering to the heat transfer surface of the heat transfer block, and when the heat transfer block is loaded into the casing. 1. A heat transfer block for an orthogonal heat exchanger, characterized in that a recess formed by the corrugated plate and the flat plate is filled with ceramic solid at a portion where the packing comes into contact.