JPH0125916Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a floating head structure in a heat exchanger, and in particular, in a shell-and-tube heat exchanger where it is necessary to alleviate stress caused by thermal expansion, the invention relates to a floating head structure in a heat exchanger. The present invention relates to a sealing structure for movably sealing a trunk lid.

2. Description of the Related Art As a heat exchanger for heating or cooling a fluid, a shell-and-tube heat exchanger is often used when contamination of heat transfer tubes is avoided or when it is desired to lower fluid flow resistance. In this case, there is inevitably a temperature difference between the tube side and the shell side, and depending on the properties of the fluid, it may be necessary to construct part of the heat exchanger from materials with different coefficients of thermal expansion. Since the heat exchanger tubes and the shell exhibit different thermal expansions, it is required that at least one of the tube sheets of the shell-and-tube heat exchanger is not fixed to the shell.

In such cases, the tube sheet is usually attached to the floating head and housed in the body cover, and the fluid in the tube flows in from the fixed tube sheet side, turns around inside the floating head, and flows out again from the other half on the fixed tube sheet side. is configured to do so. However, if you want to configure the tube so that the fluid passes from one side of the heat exchanger to the other without turning around, it is necessary to provide a movable sealing structure between the tube plate and the body, and also Since a movable sealing structure is also required to avoid the effects of expansion and contraction due to thermal expansion on the piping, the structure of the heat exchanger is complex, prone to failure, and difficult to maintain.

Problem to be solved: In multi-tube heat exchangers in which the fluid inside the tubes passes from one side to the other, and in which one tube plate is movably sealed to the body, failures such as leaks are less likely to occur. The purpose of the present invention is to provide a sealing structure that does not lead to accidents even if leakage occurs and is easy to maintain.

Means for Solving In order to achieve the above-mentioned object, the present invention forms the outer periphery of at least one tube plate of a multi-tubular heat exchanger into a cylindrical shape, and seals between the shell and the shell cover. The outer periphery of the tube plate and the shell and shell lid are simultaneously sealed by a means, and this sealing means is constructed by stacking annular members.

Hereinafter, the configuration of the present invention will be explained based on the drawings.

Fig. 1 is a cross section of the tube sheet sealed portion of a multi-tube heat exchanger, where 1 is the shell, 3 is the shell side flange, 4 is the shell cover, 5 is the shell cover side flange, 6 is the heat transfer tube, and 7 is the shell side flange. is a tube plate, and a cylindrical portion 7a is provided on its outer periphery. 8
is the outlet of the fluid inside the tube. A sealing means 10 is provided between the shell side flange 3 and the shell cover side flange 5, and is fastened together with both flanges 3 and 5 with bolts 9. 2 is a body side fluid port.

The structure of the sealing means 10 is as shown in FIG. In other words, 18 and 19 are the upper and lower seat packings,
11 is a first ring, 14 is a seat ring, and 15 is a second ring. The first ring 11 and the second ring 15 have a mutually almost symmetrical structure and have a space 11a or 15a for accommodating the O-ring 12 or 16, respectively, and the O-ring is arranged downwardly or upwardly. An annular convex portion 1 to prevent deviation in the direction
1b or 15b. In each space 11a or 15a, there are 2
Individual O-rings 12, 12 or 16, 16 are accommodated, and backup springs 13 or 17 are fitted between the O-rings, respectively. The seat ring 14 installed between the first ring 11 and the second ring 15 has a width sufficient to back up the O-rings 12 and 16 so that they do not come off, and has shallow radial grooves 14a on the upper and lower surfaces. There are two each.

Function The multi-tubular heat exchanger having the tube plate sealing structure configured as described above has a structure such that the fluid in the tubes flows inside the body cover 4, and the cylindrical portion 7a of the tube plate 7 is
The ring 12 seals the body and the O-ring 1.
It is sealed with the barrel lid by 6. And between these O-rings 12 and 16 is a seat ring 1.
4, but the seat ring 14 is provided with a groove 14a and communicates with the atmosphere, so when a leak occurs in the O-ring 12 on the shell side, the shell side fluid flows through the groove 14a.
4a, but as long as there is no leakage in the O-ring 16, it will not mix into the fluid in the pipe. Conversely, when leakage occurs in the O-ring 16 on the shell side, the fluid in the tube flows out from the groove 14a, but does not mix into the shell side fluid. Furthermore, the same applies when the heat exchanger is used under reduced pressure, and even if air leaks, the fluid in the pipes and the fluid on the body side will not mix, resulting in a double-prevented sealed structure. ing.

In addition, even if a leak occurs, by examining the fluid leaking from the groove 14a, it is possible to immediately know which O-ring is damaged, the one on the shell side or the one on the shell cover side, which is effective in speeding up repair work. be.

Effects of the invention As detailed above, although the floating type tube sheet sealing structure of the present invention has a very simple and compact structure, it is possible to immediately know the location of damage when leakage occurs in the sealed part. To realize an economical heat exchanger which is capable of doubly preventing mixing of the fluid in the pipes and the fluid on the body side, which significantly reduces the occurrence of accidents, and which greatly facilitates maintenance management. I was able to do that.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a shell-and-tube heat exchanger equipped with a floating tube sheet sealing structure according to the present invention, and FIG. 2 is an enlarged view of the sealing structure. . 1... shell, 4... shell lid, 6... heat exchanger tube, 7...
Tube sheet, 10... Tube sheet sealing means, 11... First ring, 14... Seat ring, 15... Second ring, 12, 16... O ring.

Claims (1)

[Scope of utility model registration request] When sealing the floating side tube sheet of a multi-tube heat exchanger, a cylindrical portion having an outer diameter that allows movement inside the shell is provided on the outer periphery of the tube sheet, and a seal provided between the shell and the shell lid. A structure in which the cylindrical portion, the body, and the body lid are simultaneously sealed by a sealing means, the sealing means comprising a first annular packing provided in contact with the body side;
an annular convex portion having a space therein for accommodating an O-ring for sealing a side surface of the cylindrical portion and preventing the O-ring from deviating toward the first packing, and being in contact with the first packing; a first ring provided;
A seat ring provided in contact with the first ring and a side surface of the cylindrical portion, the seat ring having a width sufficient to prevent the O-ring from coming off and having a plurality of grooves extending from the inside to the outside on at least one surface. a second ring provided in contact with the seat ring, the ring having an annular convex portion having a space therein for accommodating a stopping O-ring and preventing the O-ring from escaping in a direction opposite to the seat ring; , a second annular packing provided in contact with both the barrel lid side and the second ring;