JPH0625760Y2 - Ceramic tube gripping structure and connection structure - Google Patents

Description

[Detailed Description of the Invention] [Field of Application] The present invention is suitable for, for example, a heat exchange device and a dust removing device.
The present invention relates to a holding structure and a connecting structure for a ceramic tube.

“Prior Art” In recent years, it has been proposed to use ceramic tubes that can be applied to high-temperature gas as heat transfer tubes for heat exchange devices and filter tubes for dust removers, but there are various technical difficulties in using these ceramic tubes. Accompany.

That is, since a ceramic tube is weaker than a metal tube against mechanical and thermal shocks and is easily broken, a long tube cannot be used. In addition, when the ceramic tube and the metal member are assembled, expansion and contraction due to a difference in thermal expansion occurs, and the ceramic tube is often damaged due to excessive stress. Further, for connecting the ceramic tube and the metal member, ordinary connecting means such as welding and bolting cannot be adopted.

In order to solve these problems, the present applicant proposes a structure in which the outer peripheral portion of the ceramic tube is gripped by a metal ring via a heat-expandable mat, and further, such a metal ring and the metal tube plate are connected to gas tight. (Japanese Patent Application No. 61-172898). In this structure, the ceramic tube is strongly gripped by the metal ring due to the expansion force of the heat-expandable mat, and since all the constituent members have sufficient heat resistance, for example, treatment of gas at a temperature of 500 ° C or higher. It can also be applied to devices.

[Problems to be solved by the invention] However, according to the above-mentioned structure, the vibration of the ceramic tube, which is generated for some reason during the assembling work or the operation, is directly applied to the heat-expandable mat as a shearing force, and thus the heat-expandable mat. The gripping force of may deteriorate. Further, when deteriorated, the heat-expandable mat easily scatters, which causes a problem of gas leakage.

An object of the present invention is to solve the above problems and to provide a joint structure between a ceramic tube and a metal ring, which has excellent heat resistance, does not require cooling of the tube sheet, and has excellent sealability and durability.

"Means for Solving the Problem" The present invention relates to a ceramic tube gripping structure in which a metal ring is attached to the outer periphery of a connecting portion of a ceramic tube, and a concave portion provided in the inner peripheral portion of the metal ring is provided in order from the outside. A heat-expandable mat and a gland packing are arranged, and further, a connecting structure between the ceramic tube and the tube plate or another ceramic tube, wherein the ceramic tube has the above-mentioned gripping structure. To do.

In the present invention, the heat-expandable mat is formed by bonding the heat-expandable material and the ceramic fiber and / or the ceramic fiber molded body with an organic binding material. It means that it has a characteristic that it expands up to about 3 times and then substantially maintains the expanded state even if the temperature raising and lowering is repeated. In this case, the heat-expandable material is, for example, a heat-resistant inorganic expansive material such as vermiculite or pearlite, and the ceramic fiber is, for example, a fibrous inorganic material containing alumina and / or silica as a main component. . As the ceramic fiber molded body, for example, silica cloth is used, and in this case, the silica cloth may be sandwiched with a heat expansion material. Specific examples of such a heat-expandable mat include "Interlamm mat" (trade name, manufactured by Sumitomo 3M Limited).

The present invention utilizes such characteristics of the heat-expandable mat, and the heat-expandable mat in an unexpanded state and the gland packing are arranged in order from the outside in the concave portion of the inner circumference of the metal ring,
When these are inserted into the outer circumference of the connection part of the ceramic tube and the part is heated to a temperature at which the heat-expandable mat expands, for example, 400 ° C or higher, the heat-expandable mat expands and the gland packing is strongly compressed, and the metal ring Holds the ceramic tube firmly. Once the heat-expandable mat expands, it maintains its expanded state even after the temperature becomes low, so that the mat can be connected to obtain a sufficient gripping force and provide a good sealing property.

Further, due to handling during assembling work, a pressure difference between the inside and outside of the ceramic tube during operation, etc., a shearing force is often generated between the outer circumference of the ceramic tube and the inner circumference of the metal ring. At this time, if the heat-expandable mat is in direct contact with the outer circumference of the ceramic tube, the heat-expandable mat gradually collapses from this contact surface, and the required gripping force and sealing performance tend to be reduced. On the other hand, in the present invention, since the heat-expandable mat is accommodated in the space closed by the concave portion of the metal ring and the gland packing, such troubles can be avoided. Forming an inward flange at one end of the metal ring and bringing the inner bottom surface of the inward flange into contact with the end surface of the ceramic tube is particularly effective in preventing the gripping force and the sealing performance from being deteriorated by shearing force.

In addition, the usual method of using gland packing, that is, packing the gland packing only in the stuffing box and compressing it with the packing retainer can be used when the metal tube is held by the metal ring, but the ceramic tube is When gripping with a ring, the gland packing alone is too stiff,
The difference in thermal expansion in the radial direction between the ceramic tube and the metal ring cannot be absorbed. In the present invention, not only the gland packing but also the corresponding elasticity of the heat-expandable mat is utilized, so that the difference in thermal expansion between the metal ring and the ceramic tube can be absorbed. There is also an advantage that it fits compactly because it does not require a packing presser.

Further, in the present invention, since the metal ring is connected to the tube sheet or another ceramic tube, the heat treatment for expanding the heat-expandable mat in advance can be performed with the metal ring attached to the ceramic tube. No need to do after connecting to a plate or another ceramic tube. At that time, by connecting the metal ring to the tube plate or another ceramic tube via the bellows, it is possible to secure a good sealing property while allowing expansion and contraction due to a difference in thermal expansion and positional deviation due to an installation error. At the time of such connection, it is convenient to form an outward flange on the outer periphery of the metal ring.

Furthermore, instead of connecting the ceramic tube directly to the tube sheet via the heat-expandable mat, it is connected to the metal tube sheet via the metal ring, so when connecting to the tube sheet, screw fastening, load It is possible to press and fix by using, and it becomes easy to attach and detach the ceramic tube to and from the metal tube plate, and it becomes easy to perform the work in assembling and repairing. In particular, by forming a spherical surface on the outer circumference of the metal ring and placing it on the insertion hole of the tube sheet with this spherical surface facing downward, welding or screw fastening in a narrow space is not required. Moreover, even if the axis of the ceramic tube is slightly inclined from the predetermined direction, sufficient sealing performance can be secured.

In the gripping structure of the present invention, as described above, the gripping and sealing are performed well. Therefore, when only gripping is required, the recesses may be provided intermittently in the circumferential direction of the metal ring, and the heat-expandable mat and the gland packing may be disposed only in the recesses. When the sealing property is also required, it is preferable that the concave portion is provided all around the circumference of the metal ring, and the heat-expandable mat and the gland packing are also arranged all around the circumference. When the present invention is applied to a heat exchange device, the metal ring and the metal tube plate may be connected to gas tight, and when it is applied to the dust removing device, the metal ring and the metal tube plate are not. It should be connected to Dust tight.

In the present invention, since the ceramic tube, metal ring, and heat-expandable mat all have sufficient heat resistance, by adopting a heat-resistant gland packing, even when applied to a high-temperature gas treatment device at 500 ° C or higher, for example. The cooling means for protecting the gripping portion and the connecting portion, for example, a water-cooled tube plate is not essential, and therefore heat loss is also reduced. When a water-cooled tube sheet is used, the can body in the tube sheet part and the can body in the non-tube sheet part may cause a difference in expansion and contraction in the can body radial direction, which may distort the peripheral wall of the can body. Insulation lining was required on the wall. However, if the cooling tube sheet is not used according to the present invention, the above-mentioned lining of the heat insulating material is not required.

"Embodiment" FIG. 1 shows a first embodiment of the present invention. A ceramic ring 1 having an outer diameter of 163 mm, which functions as a heat transfer tube for a heat exchange device, has a metal ring formed on one outer peripheral portion with a gland packing 2 and a heat-expandable mat 3 to form a concave portion having a U-shaped cross section along the entire inner periphery. 4 is installed. An outward flange 7 is formed on the outer periphery of the upper portion of the metal ring 4, and the outward flange 7 engages with the upper edge portion of the insertion hole of the tube sheet 5 and is fixed by tightening with a bolt 8 via a gasket 6. . The inner diameter of the metal ring 4 is 166 mm, the inner diameter of the recess is 179 mm, and the axial length of the recess is 70 mm.
And

As the gland packing 2, a 5 mm square "CHIRON packing" was used. It contains Inconel wire and has a heat resistance of 600 ℃ or higher. As the heat-expandable mat 3, "Interlam mat" was used. It consists of vermiculite, ceramic fibers and organic binders, and expands significantly at temperatures above 400 ° C. "Intarum mat" with an initial thickness of 5 mm was compressed to a thickness of 3 mm in advance, and this was packed over the entire circumference of the concave portion of the metal ring 4, and the gland packing 2 was also packed over the entire circumference, and then inserted into the ceramic tube 1. Then, this site was kept at 550 ° C. for 1 hour. The gripping portion thus obtained exhibited a sufficient gripping force of 300 kg or more at room temperature.
This performance can be expected to be equal or higher even in the temperature range of about 500 ° C.

The holding portion of the ceramic tube 1 by the metal ring 4 is the upper end portion in this example, but may be the upper portion, the central portion or the lower portion of the ceramic tube 1, and a single portion may be used to hold a plurality of portions. You may grasp with. Further, in this example, the metal ring 4 and the metal tube plate 5 are screwed together with the bolts 8 via the gasket 6, but in an environment where it is difficult for humans to approach,
For example, for nuclear power, the structure may be such that a heavy weight is used to apply a load and push it.

FIG. 2 shows a second embodiment of the present invention. The outer peripheral portions of the upper ends of the ceramic tubes 10 and 20 functioning as filter tubes of the dust remover are held by metal rings 30 and 40, respectively. An inward flange 31 and an outward flange 32 having an inner diameter larger than the outer diameter of the ceramic tube 10 are formed at the lower end of the metal ring 30.
An inward flange 33 having an inner diameter smaller than the outer diameter of the ceramic tube 10 is detachably provided at the upper end of the metal ring 30 by bolt fastening (the position thereof is not shown in the figure by a dashed line, the same applies hereinafter). The upper end surface 11 of the ceramic tube 10 is in contact with the inner bottom surface 34 of the inward flange 33.

In the concave portion formed by being sandwiched between the inward flange 31 and the inward flange 33, as shown in the figure, the heat-expandable mat 14 in an unexpanded state is arranged on the outside, and the gland packing 13 is arranged on the inside thereof. By subjecting this part to a predetermined heat treatment, the heat-expandable mat 14 expands, and the gland packing
The 13 and the ceramic tube 10 are brought into pressure contact with each other, and the outer periphery of the upper end of the ceramic tube 10 is sufficiently gripped by the metal ring 30. Many of the heat-expandable mats 14 expand anisotropically, and in that case, it is preferable to arrange them so that the main direction of expansion is the radial direction. Similarly, the outer periphery of the upper end of the ceramic tube 20 has a metal ring 40.
Is gripped at.

The outer periphery of the lower end of the ceramic tube 10 is held by the metal ring 35. An inward flange 36 having an inner diameter larger than the outer diameter of the ceramic tube 10 is formed at the upper end of the metal ring 35,
A downward spherical surface portion 37 is formed on the outer peripheral portion of 35. At the lower end of the metal ring 35, an inward flange 39 having an inner diameter smaller than the outer diameter of the ceramic pipe 10 is detachably provided by bolt fastening, and the lower end surface 12 of the ceramic pipe 10 is provided with the inward flange 39. It is in contact with the inner bottom surface 38. The heat-expandable mat 14 and the gland packing 13 are arranged in a concave portion formed by being sandwiched between the inward flange 36 and the inward flange 39, and further subjected to heat treatment, and the lower end outer peripheral portion of the ceramic tube 10 becomes a metal ring 35. Be gripped.

The lower end flange 16 of the bellows 15 is bolted onto the outward flange 32, and the upper end flange 17 of the bellows 15 is bolted onto the tube sheet 51. Further, the lower end flange 26 of the bellows 25 is bolted onto the outward flange 42 of the metal ring 40, and the upper end flange 27 of the bellows 25 is bolted onto the outward flange 39. Tube sheet ring with tapered surface 55
54 is fixed on the tube sheet 52, and the spherical surface portion 37 is engaged with the tapered surface 55 to support the metal ring 35 while ensuring sealing performance.
Metal tube plates 51 and 52 are water chambers 53 through which cooling water flows.
In addition to the metal tube plates 51 and 52, the bellows 15 and 25 are prevented from overheating.

In this example, similarly to the first embodiment, not only the radial expansion difference between the ceramic tube and the metal ring in the radial direction can be absorbed by the gland packing and the heat-expandable mat, but also the axis of the ceramic tube based on the difference in thermal expansion. The displacement in the direction can be absorbed by the bellows, and the reliability of the joint can be significantly improved.

[Effect of the Invention] As described above, in the present invention, the outer peripheral portion of the ceramic tube is gripped by the metal ring through the gland packing and the heat-expandable mat, so that the ceramic tube is firmly gripped by the metal ring. A good sealing property can be obtained. Further, since these inclusions can easily be made heat resistant, a cooling structure is not essential and the structure can be simplified. Further, since the ceramic tube can be fixed to the tube sheet via the metal ring without directly fixing the ceramic tube to the tube sheet, it has various advantages as described above such as easy attachment / detachment at the time of assembly and repair.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention, and FIG. 2 is a vertical sectional view showing a second embodiment of the present invention. 1: Ceramic tube, 2: Gland packing 3: Heat-expandable mat, 4: Metal ring.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP 62-123295 (JP, A) JP 59-166427 (JP, A) JP 57-123871 (JP, A) JP 58- 13683 (JP, A)

Claims (10)

[Scope of utility model registration request] 1. A ceramic tube gripping structure in which a metal ring is mounted on the outer circumference of a connecting portion of the ceramic tube, and a heat-expandable mat and a gland packing are sequentially placed from the outside in a recess provided in the inner circumference of the metal ring. A gripping structure for a ceramic tube, which is characterized by being arranged. 2. In the claim 1 of the utility model registration claim,
A grip structure in which an outward flange is formed on the outer periphery of the metal ring. 3. A utility model registration claim as set forth in claim 1.
A holding structure in which a spherical portion is formed on the outer periphery of the metal ring. 4. The utility model registration as claimed in any one of claims 1 to 3, wherein an inward flange is formed at one end of the metal ring, and an inner bottom surface of the inward flange is an end surface of the ceramic tube. A gripping structure that abuts. 5. The utility model registration as claimed in any one of claims 1 to 4, wherein the concave portion is provided over the entire circumference of the metal ring in the circumferential direction, and the heat-expandable mat and the gland packing are respectively arranged in the circumferential direction. A grip structure that is arranged around the circumference. 6. A ceramic pipe connection structure comprising a metal ring having an outward flange attached to the outer periphery of a connecting portion of the ceramic pipe, and the outward flange being fixed to a tube plate. A connection structure for a ceramic tube, characterized in that a heat-expandable mat and a gland packing are arranged in order from the outside in a recess provided in a peripheral portion. 7. A ceramic tube connection structure comprising a metal ring attached to the outer periphery of a connecting portion of the ceramic tube, and the metal ring being connected to a tube plate or another ceramic tube via a bellows. A structure for connecting a ceramic tube, characterized in that a heat-expandable mat and a gland packing are arranged in order from the outside in a recess provided in the inner peripheral part of the. 8. A connecting structure for a ceramic tube, wherein a metal ring having a downward spherical surface is attached to the outer periphery of the connecting portion of the ceramic tube, and the metal ring is mounted on a tube plate. A structure for connecting a ceramic tube, characterized in that a heat-expandable mat and a gland packing are arranged in order from the outside in a recess provided in the inner peripheral part of the. 9. A gripping structure or a connecting structure according to claim 1, wherein the ceramic tube is a heat transfer tube for heat exchange. 10. A gripping structure or a connecting structure according to any one of claims 1 to 8, wherein the ceramic tube is a filter tube.