JPH07107437B2 - Structure that connects the tube and tube plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tube-tube plate connection structure applied to a heat exchanger or a filter device using a ceramic tube.

“Prior art and its problems” Conventionally, in a heat exchanger using a metal tube, the tube has been directly welded to a tube sheet or attached by expansion. Therefore, the hermeticity between the heating fluid and the heated fluid was sufficiently maintained. However, 800 ° C
It is difficult to perform the above heat exchange of the high temperature fluid with the metal tube. In such a case, a ceramic pipe is used, but it goes without saying that in this case, connection by welding or pipe expansion cannot be performed. Further, when connecting the ceramic pipes, it is necessary to have a structure that absorbs a difference in thermal expansion and a mechanical shock generated between the ceramic pipe and the metal tube plate or the can body.

Based on the above request, the applicant has already filed Japanese Patent Application No. 60-93782.
Proposes a connection structure between a ceramic tube and a tube sheet that absorbs a thermal expansion difference and a mechanical shock generated between the ceramic tube and the tube sheet, and that secures a sufficient sealing property. However, in this connection structure, by casting an organic rubber-based buffer layer between the inorganic heat insulating layer provided on the outer periphery of the connection portion of the ceramic pipe and the water cooling wall of the water cooling structure tube plate, the ceramic pipe is formed. Since it is directly inserted and held by the holding hole of the tube sheet, it takes a lot of man-hours to inject or remove the organic rubber-based buffer layer when the ceramic tube is attached to and detached from the tube sheet. It was necessary and hindered the enlargement of the device.

"Object of the Invention" The object of the present invention is to solve the above-mentioned problems of the prior art, to simplify the connection between the ceramic pipe and the tube sheet, and further to provide the tube and the tube sheet with sufficient sealability. It is to provide a structure for connecting.

"Outline of the Invention" According to the structure for connecting the tube and the tube sheet according to the present invention, the inorganic heat insulating layer surrounds the outer circumference of the connecting portion of the ceramic tube through which the high-temperature gas flows, and the outer circumference of the inorganic heat insulating layer is A polymer-based buffer layer surrounds the buffer layer, and a metal holder surrounds the outer periphery of the buffer layer to integrate the ceramic pipe and the metal holder, and the ceramic pipe is held on the tube sheet through the metal holder. A cooling chamber in which a low temperature fluid flows is formed in the tube sheet, and the metal holder is surrounded by the cooling wall of the cooling chamber.

Therefore, since the ceramic tube can be connected to the tube sheet only by placing or connecting the connecting portion of the metal holder on the tube sheet, it becomes very easy to attach and detach the ceramic tube to the tube sheet, and the complicated on-site construction can be performed. The number of steps can be greatly reduced and the fluid can be sufficiently sealed.

Further, since the metal holder is surrounded by the cooling wall of the cooling chamber of the tube sheet, the metal holder is indirectly radiatively cooled by the low temperature fluid flowing in the cooling chamber. Then, the cooled metal holder cools the polymer buffer layer, for example, organic rubber, to a temperature at which its elasticity can be maintained, so that a difference in thermal expansion or mechanical difference between the tube and the tube sheet or the can body occurs. The shock can be effectively absorbed by the buffer layer.

To explain the present invention in more detail, the inorganic heat insulating layer is formed of, for example, a cylindrical shape so as to surround the ceramic pipe by using ceramics of the same quality as the pipe, castable refractory, mortar, or the like. In this case, the heat insulating layer is preferably made of a material that does not cause a difference in thermal expansion with the ceramic tube.

In a more preferred embodiment, the heat insulation layer is composed of an inner layer made of ceramic fibers, paper, woven cloth, etc. and an outer layer made of castable refractory. If the heat insulation layer is composed of only castable refractory layers, the thermal expansion of the heat insulation layer does not follow the thermal expansion of the ceramic tube during transient conditions such as starting, and compressive stress will be applied to the ceramic tube from the surroundings. There is a possibility that it will crack and that, on the contrary, a gap will be created between the ceramic pipe and the heat insulating layer, resulting in poor sealing performance. However, by making this heat insulating layer a double structure of such an inner layer and an outer layer, it is possible to avoid such concern due to the cushioning property and heat resistance of the inner layer.

As the polymer buffer layer, for example, a silicone rubber-based or fluororubber-based one is heat resistant, highly elastic, or
It is preferably used from the viewpoint of resistance to corrosive components in high temperature gas. The buffer layer is preferably formed by injecting an organic rubber-based substance as described above between the inorganic heat insulating layer and the metal wall constituting the metal holder, or the outer circumference of the heat insulating layer or the inner wall of the metal wall of the metal holder. It is formed so that the gap between the heat insulating layer and the metal holder is filled and sealed by being applied beforehand. Also, as the polymer-based cushioning material,
Inorganic polymers composed of enamel also have elasticity and are more preferably used from the viewpoint of heat resistance and corrosion resistance.

As still another method of forming the buffer layer, an organic rubber-based cylindrical molded product or a product obtained by winding an organic rubber-based plate in a tubular shape may be inserted into the gap between the heat insulating layer and the metal holder. Further, it is also effective that a part or all of the surface thereof is fixed by a method such as adhering and sealing with an amorphous organic rubber.

INDUSTRIAL APPLICABILITY The connection structure of the present invention can be applied to, for example, not only the connection between a ceramic heat transfer tube and a tube plate in a heat exchanger, but also the connection between a ceramic filter tube and a tube plate in a dust remover from high-temperature gas. .

"Embodiment of the Invention" Fig. 1 shows a ceramic structure of a connecting structure according to the present invention
One example is shown as applied to the lower end of 11.
When applying this connection structure to a heat exchanger, for example,
A high-temperature heating gas is caused to flow in the internal space 36 of the ceramic pipe 11, and a low-temperature heated gas is caused to flow in the external space 37. When applied to a dust remover, high-temperature dust-containing gas is caused to flow through the internal space 36 of the ceramic pipe 11 having a filter function, and clean gas that has passed through the ceramic pipe 11 flows through the external space 37.

The metal tube plate 12 has a cooling structure in which a cooling chamber 13 is formed, and the lower end connection portion of the ceramic tube 11 is inserted and held in a holding hole 15 formed by a cooling wall 14. A ceramic woven cloth 16 is wrapped around the lower end of the ceramic pipe 11, and the castable refractory layer 17 as a heat insulating material is further wrapped around the ceramic woven cloth 16.
Are arranged. A metal holder 18 is arranged on the outer periphery of the castable refractory layer 17 with a predetermined gap.

The metal holder 18 has an outer peripheral flange 19 formed at the upper end in the outer peripheral direction and an inner peripheral flange 20 formed at the lower end in the inner peripheral direction. The ceramic pipe 11 and the lower surface of the castable refractory layer 17 are in contact with the upper surface of the inner peripheral flange 20, and the castable refractory layer 17 and the metal holder
A buffer layer 21 formed by pouring silicone rubber or the like is formed in a gap formed between the buffer layer 18 and the layer 18. Then, the ceramic pipe 11 is integrated with the metal holder 18 via the buffer layer 21 and the castable refractory layer 17. The buffer layer 21 has a thickness of about 0.5 to 3 mm in this embodiment.

Further, an annular projection 22 is formed on the lower surface of the outer edge portion of the outer peripheral flange 19, and is brought into contact with a packing 23 provided near the holding hole 15 on the upper surface of the tube plate 12. Therefore, the ceramic pipe 11
The annular projection 22 is held by being abutted on the packing 23 on the upper surface of the tube sheet 12 via the metal holder 18. In this case, the packing between the annular projection 22 and the upper surface of the tube sheet 12 is performed by the packing 23. However, in order to increase the sealing surface pressure, the annular projection 22 with respect to the packing 23 is sealed.
The contact width is processed into a knife edge to reduce the width.
Although the number of steps is slightly increased, it goes without saying that the sealing surface pressure may be secured by tightening bolts.

In order to insert and hold the lower end portion of the ceramic tube 11 as described above in the holding hole 15 of the tube sheet 12, the portion of the annular protrusion 22 of the metal holder 18 integrated with the ceramic tube 11 is attached to the upper surface of the tube sheet 12. It only has to be placed on the packing 23 of. This allows
The packing 23 is subjected to its own weight of the ceramic pipe 11 and the like, and the upper surface of the tube plate 12 and the annular projection 22 are hermetically sealed via the packing 23 to prevent fluid leakage.

Therefore, according to this connection structure, the ceramic pipe
It becomes very easy to attach and detach 11 to the tube sheet 12, and the time required for assembly and open inspection is greatly reduced.

In this connection structure, assuming that the temperature of the gas passing through the ceramic pipe 11 is 700 ° C., the castable refractory layer 17 acts as a heat insulating layer, and the metal holder 18 is radiatively cooled by the cooling chamber 14. Therefore, the buffer layer 21 is about 18
It is kept cold at about 0 ° C. to retain the buffering force, and absorbs the relative displacement between the ceramic pipe 11 and the tube plate 12 due to the difference in thermal expansion and mechanical shock. Further, in a transient state such as at the time of starting, the thermal expansion of the castable refractory layer 17 does not follow the thermal expansion of the ceramic pipe 11, and stress is generated between the ceramic pipe 11 and the castable refractory layer 17. However, this stress is absorbed by the ceramic woven fabric 16.

FIG. 2 shows a ceramic pipe with a connection structure according to the present invention.
11 Another embodiment applied to the upper end is shown. In addition,
The same parts as those in FIG. 1 are designated by the first reference numerals and the description thereof will be omitted. A ceramic woven cloth 16 is wrapped around the outer periphery of the upper end of the ceramic pipe 11, and a castable refractory layer 17 held by a metal holder 18 is arranged outside the ceramic woven cloth 16. In the gap between the outer circumference of the castable refractory layer 17 and the inner circumference of the metal holder 18, a cylindrical buffer layer 21 made of silicone rubber or the like and having a thickness of about 0.5 to 3 mm is arranged. Then, the ceramic pipe 11 is integrated with the metal holder 18 via the buffer layer 21 and the castable refractory layer 17.

The ceramic tube 11 and the metal holder 18 are integrated with each other, for example, as follows. A plate-shaped temporary frame (not shown) is arranged on the outside of the ceramic pipe 11 on which the ceramic woven fabric 16 is wound in advance, and the metal holder 18 having the paste such as silicone rubber is thickly coated on the inside is used as the plate-shaped temporary frame. Place on top. The castable refractory slurry is poured onto the temporary frame in the gap between the metal holder 18 and the ceramic pipe 11, the slurry is allowed to self-harden, and then the temporary frame is removed. At this time, a main part of the castable refractory layer is a preformed product, and the castable refractory slurry may be poured or pressed into only the part in contact with the ceramic woven fabric 16 or the part in contact with the buffer layer 21. Also, if such a slurry penetrates into the ceramic woven fabric 16 too much, the ceramic woven fabric is
It is advisable to interpose a resin film on the outer periphery of 16. (When the flange 20 is provided as shown in FIG. 1, the above-mentioned temporary frame is not necessary.) The metal holder 18 has a mounting flange 24 outwardly at the upper end thereof. , Packing on the mounting flange 24
The bellows ring 26 is tightened and fixed by bolts 27 via 25. One end of a bellows 28 is attached to the outer end of the bellows ring 26. Also,
A bellows ring 30 is tightened and fixed by a bolt 31 via a packing 29 near the holding hole 15 on the upper surface of the tube plate 12, and a bellows 28 is attached to the inner end of the bellows ring 30.
The other end of is attached. In this embodiment, the bellows 28 allows the relative displacement between the tube sheet 12 and the ceramic tube 11 and ensures the sealing between the fluids.

It should be noted that heat insulating materials 32 and 33 are arranged by sticking or hanging at the lower surface position of the tube sheet 12 and the lower surface positions of the metal holder 18 and the castable refractory layer 17. Further, 34 is a ferrule-shaped heat insulating material, which is used for the ceramic pipe 11
Placed after connecting to 12.

To connect the ceramic tube 11 to the tube plate 12, the ceramic tube 11 is inserted into the holding hole 15 and the mounting structure provided in the lower portion of the ceramic tube 11 not shown in FIG. Place on a mounting table such as the omitted tube sheet.
Then, the bellows ring 26 is tightened and fixed on the mounting flange 24 with the packing 25 by the bolt 27, and the bellows ring 30 is fixed on the tube sheet 12 with the packing 29.
Tighten the bolts with bolts 31 as well. As a result, the ceramic tube 11 is connected to the holding hole 15 of the tube plate 12, and the bellows 28 reliably seals between the fluids. In this case, if either one of the bellows ring 26 and the bellows ring 30 is fixed in advance, the connecting work becomes easier.

In this connection structure, the length of the ceramic pipe 11 is 2m.
Then, it is assumed that a high temperature gas of 700 ° C. is introduced from the upper part of the ceramic pipe 11. In that case, at the beginning of inflow, only the ceramic pipe 11 becomes high temperature, the ceramic pipe 11 extends upward by about 1.5 mm, and the iron shell of the can body is about 70 ° C. about 1 hour after the inflow.
The ceramic woven fabric 16 and the buffer layer 21 absorb the difference in thermal expansion in the axial direction and the radial direction during this period, and the ceramic woven fabric 16 and the buffer layer 21 absorb the difference and the ceramic woven fabric 16 absorbs the expansion. Damage to the pipe 11 is prevented.

The buffer layer 21 has, for example, a metal holder 18 at the lower outer periphery thereof.
The castable refractory layer 17 is adhered to the inner peripheral portion, and the upper inner periphery thereof is adhered to the outer peripheral portion of the castable refractory layer 17 or adhered to the outer peripheral portion of the castable refractory layer 17 by pressure bonding using rubber elasticity. If the metal holder 18 is not adhered to the
Even if 11 causes a large relative displacement in its axial direction, it is possible to absorb this.

[Advantages of the Invention] As described above, according to the present invention, the inorganic heat insulating layer and the radiation-cooled metal holder keep the buffer layer cool enough to maintain its elasticity. Further, the buffer layer absorbs the difference in thermal expansion and mechanical shock. Also, when connecting the pipe and the tube sheet through the metal holder, a combination of packing and an outer peripheral flange with a large sealing surface pressure, or an appropriate sealing means such as a bellows is used at the connecting part, It is possible to reliably seal between them. In addition, it is extremely easy to attach and detach the tube to and from the tube sheet, and the time required for assembly and open inspection is greatly reduced. And by adopting a ceramic tube, for example,
It is possible to process high temperature gas that exceeds 1000 ° C.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an embodiment in which the connecting structure according to the present invention is applied to the lower end of a pipe, and FIG. 2 is an essential part of applying the connecting structure according to the present invention to the upper end of a pipe. FIG. 11 …… ceramic tube, 12 …… tube plate, 14 …… cooling wall,
15 …… Holding hole, 16 …… Ceramic woven cloth, 17 …… Castable refractory layer, 18 …… Metal holder, 19 …… Outer flange, 20 …… Inner flange, 21 …… Buffer layer, 22 …… Annular projection, 23,25,29 …… Packing, 24 …… Mounting flange,
26,30 …… Bellows ring, 28 …… Bellows.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Maeno 6 Asahi Glass Co., Ltd. Takasago Plant, 810 Umei, Ibo-cho, Takasago, Hyogo Prefecture (56) Reference JP-A-59-225721 (JP, A) JP Patent Showa 54-156216 (JP, A) Showa 55-13410 (JP, Y2) Showa 50-9604 (JP, Y2)

Claims (3)

[Claims] 1. An inorganic heat insulating layer surrounds an outer periphery of a connecting portion of a ceramic pipe through which a high temperature gas flows, a polymer buffer layer surrounds the inorganic heat insulating layer, and a metal surrounds the outer periphery of the buffer layer. The ceramic tube and the metal holder are integrated by being surrounded by a holder, and the ceramic tube is held by a tube plate through the metal holder, and a cooling chamber through which a constant temperature fluid flows is formed in the tube plate. The metal holder is surrounded by a cooling wall of the cooling chamber, and a structure for connecting a tube and a tube sheet is provided. 2. The pipe according to claim 1, wherein the inorganic heat insulating layer is composed of an inner layer made of ceramic fiber, paper or woven cloth and an outer layer made of castable refractory. A structure that connects to the tube sheet. 3. The polymer type buffer layer comprises at least one of a silicone rubber type, a fluororubber type or an inorganic polymer type.
A structure for connecting the tube and the tube sheet described in the item.