JPS61195288A - Pipe plate made of clad steel - Google Patents

Abstract

PURPOSE:To contrive to prevent the device form damage by immediate detecting a leakage of a process fluid or a drum side fluid by the outside monitoring by a method wherein each pipe hole on a pipe plate of a heat exchanger is divided into several blocks, a leakage notifying hole communicating with the surroundings of each pipe hole to the outer part of the pipe plate is provided at each block. CONSTITUTION:On a pipe plate 2 made of clad steel, each shallow groove 12 surrounding each adjacent pipe hole in blocks G1-G2 is communicated respectively via a leakage notifying hole 4, also connected to each outside detecting pipe 10. Accordingly, in case that a leakage of process fluid occurs due to producing a crack and the like on a seal welded part W, the leakage can be detected at the outside via a leakage notifying hole 11 through the communicating hole 4 from a clearance between the outer periphery of a heat transferring pipe 3 and the pipe hole wall surface. In case that the leakage occurs at a drum 1A side caused by the loosing of a pipe expanding part E due to the variation of operating condition and the like, the leakage can be detected at the outside via the leakage notifying hole 11, further, the leakage can be detected by each detecting pipe 10 on the block G1-G2. By the immediate leakage detecting for the fluid at each block from the outside, a trouble causing a serious damage for a heat exchanger body can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the prevention of fluid leakage on the shell side due to loosening of the joint block between the tube sheet and the heat exchanger tube of a heat exchanger, and the seal weld between the heat exchanger tube and the tube sheet. This invention relates to a clad steel tube sheet provided with a leak notification hole that allows leakage of fluid from the tube side due to cracks or corrosion to be detected from the outside.

[Prior art]

Conventionally, tube sheets for heat exchangers are made by bonding corrosion-resistant materials such as stainless steel, titanium, derconium, hastelloy, zinc, copper, etc. onto the surface of a base material that is prone to rust, such as carbon steel or low-alloy steel, and roll pressure welding. Alternatively, in the case of using clad steel coated and clad by explosive welding or the like, the fluid inside and outside the heat exchanger tube is separated by welding a seal to prevent leakage and expanding the tube at the attachment point between the tube sheet and the heat exchanger tube.

However, in this case, there is a problem in that even if a defect occurs in the seal weld, it cannot be detected immediately and the defect is unknown until the base material has corroded to some extent.

Therefore, as a countermeasure to this problem, a lining method, which requires a complicated manufacturing method, has been adopted, but this method has the problem of increasing costs.

However, in this case, if a crack or pinhole defect occurs in the seal weld and the process fluid leaks, or if the tube sheet expands from the original heat exchanger tube to loosen and the body side fluid leaks, it will be immediately fixed. There is a problem in that the heat exchanger does not leak to the outside of the heat exchanger, but leaks to the shell side after a long period of time, and as a result, it is not obvious until the heat exchanger body is seriously damaged.

[Purpose of the invention]

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and even if a defect occurs in the seal weld at the joint between the tube sheet and the heat transfer tube of a heat exchanger and process fluid leaks. In addition, even if the tube expansion part becomes loose and the fluid on the shell side leaks as a result, this is immediately detected externally and the purpose is to prevent serious damage to the heat exchanger body. be.

[Structure of the invention]

That is, the clad steel tube sheet of the present invention divides each tube type of the clad steel tube sheet attached to the heat transfer tube into several blocks, and also separates the periphery of each tube type in each block from the outside of the tube sheet. It is constructed by providing a communicating leak notification hole in each block.

〔Example〕

The present invention will be described in detail below with reference to the drawings, but first,
FIG. 1 is an enlarged side sectional view of the main parts of the tube sheet 2 at both left and right ends of the heat exchanger 1 shown in FIG.
As shown in Figure 2, which is a front sectional view taken along the line A-A in the figure,
A large number of heat exchanger tubes 3 are attached thereto.

Therefore, this tube sheet 2 is made of conventionally commonly used clad steel, and the base material 2 is easily rusted such as carbon steel or low alloy steel.
The surface of the base material 2A is coated with a corrosion-resistant material 2B by roll pressure welding or explosion pressure welding, etc., and the surroundings of each tube type to which the heat exchanger tube 3 of the base material 2A is attached are as shown in Figure 1. A shallow group 13 for the expanded tube portion E is provided as shown by the arrow in the figure, and the heat exchanger tube 3 is
is fixed to the tube plate 2 to seal against fluid leakage from the cylinder IA side.

Next, a shallow groove 12 is formed in the upper part of the group 13 around each tube type of the base material 2A of the tube sheet 2, and a small communication hole 4 provided between the tube bed walls is connected to the shallow groove 12. A leak notification hole 11 is provided to communicate this with the detection tube 10 outside the tube plate 2, and the above-mentioned multiple tube type is connected to the broken line G+ in FIG.
G z, G 3. As shown in G 4, each block is divided into several blocks, and each block is provided with a shallow groove 12 around each tube type and a leak notification hole 11 that communicates the communication hole 4 with each detection tube 10. z,
G 3. It is provided for each G4.

In the clad steel tube sheet 2 having the above configuration, each block G1. Since the surrounding shallow grooves 12 of adjacent tubes in G z , G x , and G 4 communicate with each other through the leakage hole 4 and are connected to each of the external detection tubes 10 , the seal welded portion If a crack occurs in W and the process fluid leaks, pass it through the communication hole 4 through the gap between the outer periphery of the heat exchanger tube 3 and the sound wall surface, and connect it to the leak notification hole 11.
Detected externally via .

In addition, the expanded pipe section E may become loose due to fluctuations in operating conditions, etc.
Even if a leak occurs on the cylinder IA side, it can be detected externally through the leak notification hole 11 in the same way, and can also be detected by the detection tubes 10 for each block G r , G z , G s , and G a. .

Next, a tube sheet 2 according to another embodiment of the present invention shown in FIG. 5, which is a side sectional view of the main part in FIG. It has almost the same configuration and function as the embodiment shown in the figure, and the same parts are indicated by the same part numbers, but in this embodiment 2, the base material 2A is A groove 14 communicating with the periphery of each tube type of each block G, c, , c, , G, and a detection tube between this groove 14 and the outside of the tube plate 2 Similarly to the embodiment shown in FIG. 1, the leak notification hole 11 communicating with the leak notification hole 10 is communicated with the leak notification hole 11 to enable detection from the outside.

The outer diameter d of the groove 14 is the pitch of the groove 14 or the outer diameter d of the groove 14.
When the distance between the centers 010 is p, a=1. ip. As a result, the grooves 14 communicate with each other at a portion thereof.

〔Effect of the invention〕

Therefore, if the present invention is adopted, it becomes possible to employ a clad steel pot plate that has been generally used in the heat exchanger, and it is possible to reduce costs.

In other words, even if process fluid leaks due to a defect in the seal weld, or if fluid leaks from the body due to loosening of the expanded tube due to fluctuations in operating conditions, etc., the problem must be immediately removed externally for each block. can be detected,
This has the effect of preventing accidents that would cause serious damage to the heat exchanger body, and also has the advantage of being able to quickly and accurately detect the location of the leak.

[Brief explanation of drawings]

FIG. 1 is an enlarged side sectional view of the main part of the tube plate of the heat exchanger shown in FIG. 6 in one embodiment of the present invention, and FIG. 2 is an A-A in FIG. 1.
3 is a schematic front sectional view of the tube sheet of FIG. 6, FIG. 4 is an enlarged side sectional view of the main portion of the tube sheet of another embodiment,
5 is a schematic front view of the surface of the base material shown in the direction BB of FIG. 4, and FIG. 6 is a side view of the heat exchanger of FIG. 1. 2... Tube plate, 3... Heat exchanger tube, 4... Leak notification hole, 10... Detection hole, 12... Shallow groove, 14.15...
- Groove, G l, G z. G,,G,...Block.

Claims (1)

[Claims] Each tube hole in the clad steel tube sheet attached to the heat exchanger tube is divided into several blocks, and leak detection holes are provided in each block to communicate between the periphery of each tube hole in each block and the outside of the tube sheet. A clad steel tube sheet characterized by: