JPH0443752Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a bayonet type heat exchanger having a heat exchanger tube made of ceramic, and more particularly to a holding structure for a heat exchanger tube made of ceramic.

"Prior Art and its Problems" In recent years, ceramic heat transfer tubes have come into use to enable heat exchange of high temperature fluids of, for example, 1000° C. or higher. When using ceramic heat exchanger tubes, care must be taken regarding the retaining structure for retaining the heat exchanger tubes on the tube plate. BACKGROUND ART Conventionally, methods such as welding and tube expansion have been used to connect a tube sheet of a heat exchanger and a heat exchanger tube, for example, in the case of a metal heat exchanger tube. However, when ceramic heat exchanger tubes are used, the difference in thermal expansion coefficient between ceramic and metal may cause damage to the ceramic or fluid leakage, so the connection method for metal heat exchanger tubes is used as is. I couldn't do it. In particular, in a bayonet type heat exchanger, an effective retention mechanism when the heat exchanger tubes are made of ceramic has not yet been known.

``Purpose of the invention'' The purpose of the invention is to maintain the heat exchanger tubes in a bayonet type heat exchanger having ceramic heat exchanger tubes so as to prevent damage to the ceramics and leakage of fluid.

``Structure of the invention'' The bayonet type heat exchanger according to the invention includes a ceramic outer cylinder whose one end is supported by a tube sheet and the other end is closed, and whose one end is supported by the tube sheet and the other end is inside the outer cylinder. The heat exchanger tube has a heat exchanger tube consisting of an inner tube inserted into the tube and opened, a flange being formed at the open end of the outer tube, and a receiving surface to which the end surface of the flange is formed in close contact with the tube plate. A holding disk is engaged with the flange, and this holding disk is urged toward the tube sheet by a biasing means, so that the end surface of the flange and the receiving surface of the tube sheet are pressed together.

In this way, since the flange end surface of the outer cylinder is pressed against the receiving surface of the tube plate by the biasing means, leakage of fluid can be reliably prevented. Furthermore, even if a difference in thermal expansion occurs between ceramic and metal at high temperatures, the biasing means absorbs this dimensional change, so that no excessive stress is applied to the ceramic outer cylinder, and the outer cylinder is prevented from being damaged. There isn't.

According to a preferred embodiment of the invention, a spring or a hydraulic mechanism is used as the biasing means. Various springs such as coil springs and bellows springs can be used, and the material is preferably a heat-resistant alloy. As the fluid pressure mechanism, for example, a mechanism may be employed in which a pressurized liquid such as water or nitrogen or a body is introduced into a cylinder into which a piston is inserted, and pressure is applied to the pivot.

According to a further preferred embodiment of the invention, the flange, the retaining disk and the outer cylinder of the biasing means are surrounded by a water cooling jacket provided in the tube sheet. In this way, by radiant cooling the holding portion of the outer cylinder using the water cooling jacket, it is possible to prevent strength deterioration of the holding portion due to heat.

"Embodiment of the invention" FIG. 1 shows an embodiment of a bayonet type heat exchanger according to the invention.

The heat exchanger tube 11 consists of an outer cylinder 12 made of ceramic and an inner cylinder 13 made of heat-resistant metal. The outer cylinder 12 is closed at its lower end and has a flange 12a at its upper opening.
is formed. A holding disk 15 is engaged with the lower surface of the flange 12a via a heat insulating ring 14. Bolts 1 are attached to the protruding piece 17 of the lower tube plate 16.
8 is inserted through the bolt 18, and the lower end of the bolt 18 is screwed onto the holding disk 15. A spring 19 is interposed between the head of the bolt 18 and the protruding piece 17, so that the bolt 18 urges the holding disk 15 upward.

A receiving ring 20 is fixed to the lower tube plate 16, and the central portion of the receiving ring 20 extends downward in a cylindrical shape, and the lower end serves as a receiving surface 20a. Then, the holding disk 15 urged upward pushes up the flange 12a of the outer cylinder 12 via the heat insulating ring 14, and the end face of the flange 12a and the receiving ring 20
The receiving surface 20a of is crimped. In this case, the contact surfaces between the flange 12a and the receiving surface 20a are both smoothed. A water cooling jacket 21 formed inside the lower tube plate 16 covers the outer periphery of these holding portions.
is surrounded by The inner cylinder 13 has an upper end portion gradually enlarged in diameter in a tapered shape, and is fixed to the upper tube plate 22 with bolts 23. In addition, the lower end of the inner cylinder 13 is connected to the outer cylinder 12.
It is inserted inside and opened. The outer periphery of the attachment portion at the upper end of the inner cylinder 13 is surrounded by a water cooling jacket 24 of the upper tube plate 22.

Further, both the lower tube sheet 16 and the upper tube sheet 22 are covered with a heat insulating material 25. Note that the heat insulating material 25 is also provided on the inner periphery of the enlarged diameter portion of the upper end of the inner cylinder 13. The flow path 26 is connected to the outer cylinder 1.
2 and the inner cylinder 13, further passes through the inner cylinder 13, and communicates with the outlet 27. In addition, the flow path 28
are orthogonal to the outer cylinder 12 of the heat exchanger tube 11.

In this bayonet type heat exchanger, for example, the heating fluid HL flows through the flow path 28, contacts the outer cylinder 12 of the heat transfer tube 11, and heats the outer cylinder 12. The heated fluid CL passes through the flow path 26 and passes through the outer cylinder 12 and the inner cylinder 13.
It passes through the gap, turns around at the lower end of the outer cylinder 12, passes through the inner cylinder 13, and flows out from the outlet 27. Therefore, when the heated fluid CL passes through the gap between the outer cylinder 12 and the inner cylinder 13a, the heated fluid CL passes through the wall of the outer cylinder 12.
Heat exchanged with HT.

In such heat exchange, the end face of the flange 12a of the outer cylinder 12 of the heat transfer tube 11 is pressed against the receiving surface 20a of the receiving ring 20 by the biasing force of the spring 19, so that leakage of liquid is prevented. Furthermore, even if dimensional changes occur between the ceramic outer cylinder 12, the metal receiving ring 20, the holding disk 15, and the bolts 18 due to differences in thermal expansion coefficients at high temperatures, the spring 19 absorbs this change. Therefore, it is possible to prevent a change in the contact pressure between the flange 12a and the receiving surface 20a. Therefore, damage to the ceramic outer cylinder 12 can be prevented, and liquid leakage can also be prevented.

Further, a water cooling jacket 21 of the lower tube plate 16 is arranged around the outer periphery of the attachment part of the outer cylinder 12, and
Since the water cooling jacket 24 of the upper tube plate 22 is disposed around the outer periphery of the attachment part, deterioration in the strength of the metal parts of the attachment part due to high temperatures is prevented. Further, since the heat insulating material 2 is also provided on the enlarged diameter inner periphery of the upper end of the inner cylinder 13, the attachment part of the inner cylinder 13 is prevented from coming into direct contact with the high temperature fluid. In addition, heating fluid
HT flows through channel 26, and heated fluid CL flows through channel 2.
8 may be used.

FIG. 2 shows another embodiment of the bayonet type heat exchanger according to the present invention.

In this embodiment, a fluid pressure mechanism is used in place of the spring 19 of the above embodiment. That is,
A cylinder 29 is formed in the lower tube plate 16, and a piston 30 is inserted into the cylinder 29.
Then, the bolt 18 is connected to the piston 30,
The bolt 18 is inserted through the bottom of the cylinder 29, and its lower end is screwed onto the holding disk 15. Furthermore, heating fluid is introduced into the cylinder 29 through the heating fluid passage 31 .

Therefore, the piston 30 is pushed up by the heated fluid introduced into the cylinder 29, which in turn pushes up the bolt 18 and the retaining disk 15, and the retaining disk 15 presses and fixes the flange 12a of the outer tube 12 against the receiving surface 20 of the receiving ring 20. Even in this embodiment, even if dimensional changes occur due to differences in the thermal expansion coefficients between the ceramic outer tube 12 and the metal receiving ring 20, the retaining disk 15, and the bolt 18 at high temperatures, the heated fluid absorbs the changes, and the flange 12a is fixed in place.
This can prevent any change in the contact pressure between the contact surface 2a and the receiving surface 20a.

"Effect of the invention" As explained above, according to the invention, a flange is formed at the open end of the outer cylinder, a receiving surface is formed on the tube plate to which the end surface of the flange is brought into close contact, and a retaining disk is attached to the flange. This retaining disk is urged toward the tube sheet by the urging means, and the end face of the flange and the receiving surface of the tube sheet are crimped, so that the ceramic outer cylinder and this Even if a dimensional change occurs due to a difference in coefficient of thermal expansion between the metal receiving surface or holding disk that holds the flange, the biasing means absorbs this dimensional change and maintains a predetermined contact pressure between the flange and the receiving surface. It can be crimped and held. Therefore, it is possible to prevent fluid leakage and damage to the ceramic outer cylinder.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing one embodiment of a bayonet type heat exchanger according to the present invention, and FIG. 2 is a sectional view of a main part showing another embodiment of a bayonet type heat exchanger according to the present invention. . In the figure, 11 is a heat transfer tube, 12 is an outer cylinder, 12a is a flange, 13 is an inner cylinder, 14 is a heat insulating ring, 15 is a holding disk, 16 is a lower tube plate, 17 is a projecting piece,
18 is a bolt, 19 is a spring, 20 is a receiving ring, 20a is a receiving surface, 21 is a water cooling jacket,
22 is an upper tube plate, 24 is a water cooling jacket, 25 is a heat insulating material, 26 is a flow path, 27 is an outlet, 28 is a flow path,
29 is a cylinder, and 30 is a piston.

Claims (1)

[Claims for Utility Model Registration] (1) A ceramic outer cylinder with one end supported by a tube plate and the other end closed; one end supported by the tube plate and the other end inserted into the outer cylinder and opened. In a bayonet type heat exchanger having a heat transfer tube consisting of an inner cylinder and an inner cylinder, a flange is formed at the open end of the outer cylinder, and a receiving surface is formed in the tube plate to which the end face of the flange is tightly attached. a retaining disk is engaged with the flange, and this retaining disk is urged toward the tube sheet by a biasing means, so that the end surface of the flange and the receiving surface of the tube sheet are pressed together, and the flange is pressed against the receiving surface of the tube sheet. A bayonet type heat exchanger, characterized in that outer peripheries of the holding disk and the urging means are surrounded by a water cooling jacket provided on the tube plate and are radiantly cooled. (2) Utility Model Registration Claim 1. The bayonet heat exchanger according to claim 1, wherein the biasing means includes a spring. (3) The bayonet heat exchanger according to claim 1, wherein the urging means is a fluid pressure mechanism.