JPS6341795A - Multi-tubed, cylindrical heat exchanger - Google Patents

Abstract

PURPOSE:To provide a compact heat exchanger in which heat conducting pipes are arranged without occupying an unnecessary space and securely connected by a constitution in which the inner surface of the shell has a clad layer and a pipe plate consists of a flat disc having a male thread on its outer circumference which engages a female thread on the inner surface of the shell for fixing. CONSTITUTION:The shell 1 has on its inner surface a clad layer 2 consisting of an anti-corrosive metallic material such as zirconium, stainless steel etc., and comprises a multi-layered cylinder which, on account of a fact that the outer layer tightens the inner layer, make use of the so-called outer pressure effect in order to equalize the stress when in use. The end plate 3 is butt-welded all around to the shell 1, and has a nozzle 4 on its top and a same clad layer 2 on its inner surface. A pipe plate 5 has a same clad layer 2 bonded to one side of a flat steel disc, and is screwed by engaging a male thread 5a on its outer circumference with a female thread 1a on the inner surface at an end of the shell 1. As the clad made of the anti-corrosive metallic material on the pipe plate 5 is completely bonded to the base steel, and heat conducting pipes are arranged without occupying an unnecessary space and are securely connected, the heat exchanger can be improved in its quality and made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multi-tube cylindrical heat exchanger used in heavy and chemical industrial plants and handling corrosive fluids.

<Prior Art> Conventionally, as this type of multi-tube cylindrical heat exchanger, there is one shown in FIG. 3, for example. In this heat exchanger, a cladding 21 made of a corrosion-resistant material such as titanium, zirconium, or stainless steel is explosively bonded to the inner surface of a disk-shaped steel tube sheet 2° having a mouth-shaped cross section, and a cladding 21 made of a corrosion-resistant material such as titanium, zirconium, or stainless steel is made of the same corrosion-resistant material that runs through the tube sheet 20. The tips of a large number of heat transfer tubes 22 made of
Single-walled shells 23 each having a cladding 21 made of the above-mentioned corrosion-resistant material on its inner periphery. The end plate 24 and the nozzle 25 are sequentially butt-welded all around to form a corrosive fluid channel 26, and an outer cylinder 27 is joined to the end surface of the tube plate 2o on the heat transfer tube side. The heat exchanger shown in FIG. 4 is a conventional example in which high internal pressure acts on the channel portion 26, and in this heat exchanger, a multilayer side 28 made of a multilayer cylinder instead of the single-walled body shown in FIG. is used.

<Point of intersection to be solved by the invention> However, since the above-mentioned conventional heat exchanger has a tube plate with a 2° or mouth-shaped cross section, when the cladding 21 is explosively bonded, due to its shape characteristics, as shown in FIG. However, there is a serious drawback in that the cladding of the central part 29 and corner part 3o of the tubesheet does not bond satisfactorily metallurgically to the base material w420. Therefore, even if the heat exchanger tubes 22 are welded and fixed to the cladding 2I of the center portion 29 and corner portions 30, the stress due to the hydraulic pressure, expansion, and contraction that acts on the heat exchanger tubes 22 when the heat exchanger is used is absorbed by the original structure. Heat exchanger tubes cannot be placed in these parts because they cannot be supported by the JLI20 component, which results in a wasteful heat exchanger with a large internal diameter, as well as This will leave a big problem with the quality itself. In addition, the conventional heat exchanger described above has three butt welded joints all around the circumference, and each welded joint requires stress relief annealing after welding, except for the multilayer body part, which is labor-intensive to manufacture. There is a drawback that the annealing temperature of ~650°C deteriorates the corrosion resistance performance, shear strength, etc. of the corrosion-resistant materials of the heat exchanger tubes 22 and cladding 21.

FIG. 6 is a sectional view of a conventional heat exchanger that avoids butt welding of the tube plate 31 and end plate 32 all around (Japanese Patent Laid-Open No. 47-194
5 (Publication No. 1). In this heat exchanger, a titanium clad steel joint ring 34 is welded to the end face of a steel outer shell flange 33, a titanium tube plate 31 is welded to this joint ring 31t, and a titanium end plate 32 is welded to the joint ring 31t. An annular spacer 35 made of titanium is welded to the outer periphery of the end, and an annular flange 36 fitted onto the end plate 32 is brought into contact with the annular spacer 35, thereby forming an annular flat 36. The tube plate 31 and the outer shell flange 33 are fastened together with bolts 37 and nuts 38, 38, and the end plate 32 is fixed to the tube plate via a packing 39. However, in this heat exchanger, the diameter of the tube plate 31 becomes large, and the outer shell flange 33 and the annular flange 36 protrude from the outer periphery, making it impossible to make the container compact. Furthermore, because of the bolt-tightening structure using packing, the end plate 32 The disadvantage is that leaks are likely to occur when high pressure is applied inside. In addition, regarding the labor and cost of manufacturing, the outer shell flange 33, the nine-hand ring 34. tube plate 3
Fig. 3, Fig. 4.
There is no major difference from the conventional example shown in the figure.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to completely bond the cladding made of a corrosion-resistant material to the base steel, so that the heat exchanger tubes can be arranged without waste and reliably joined, and the heat exchanger can be made more compact. By providing a multi-tube cylindrical heat exchanger that hardly requires stress relief annealing, which is time-consuming and degrades the performance of corrosion-resistant materials, and which has no risk of leakage even when high internal pressure is applied to the channel portion. be.

Means for Solving the Problems> In order to achieve the above object, the multi-tube cylindrical heat exchanger of the present invention has a tube plate made of explosion bonding corrosion-resistant metal clad steel to which a large number of heat transfer tubes are attached. wherein the body portion has a cladding layer made of the corrosion-resistant metal material on the inner periphery and is formed of a multilayer cylinder, and the tube plate is a flat disk with a thread provided on the outer periphery, It is characterized in that it is fixed by being screwed into a female thread provided on the inner periphery of the body.

Effect〉 Since the tube sheet is a flat disk, the cladding made of corrosion-resistant metal material
During manufacturing, it is completely bonded to the base steel and is metallurgically bonded. Therefore, the heat exchanger tubes can be arranged on the tube plate without waste and securely fixed by welding to the cladding, and the heat exchanger can be made compact.

In addition, since the body is made of a multi-layered cylinder that has an external pressure effect, it is lightweight and can withstand high internal pressure.
When a channel portion is formed by welding an end plate or a nozzle to this body portion, the number of stress relief annealing portions can be reduced, the performance of the corrosion-resistant metal material will hardly deteriorate, and the manufacturing process can be shortened. Furthermore, since the tube plate and the body are screwed together, there is no risk of leakage of the high-pressure fluid inside, and the heat exchanger can be made more compact.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a cross-sectional view of the tube sheet portion of the multi-tube cylindrical heat exchanger of the present invention, where ■ is a cladding layer 2 made of a corrosion-resistant metal material such as titanium, zirconium, or stainless steel on the inner periphery, and an outer layer is The body part 3 is made of a multi-layered cylinder which has a so-called external pressure effect by keeping the inner layer in a tightened state to equalize the stress during use, and is butt welded to this body part l all around, and has a nozzle 4 at the tip. and an end plate having the same cladding layer 2 on the inner periphery, 5
The same cladding layer 2 was bonded to one side of a flat steel disk, and the male screw 5a provided on the outer periphery was screwed into the female screw la provided on the inner periphery of the end of the body 1 to be fixed. A large number of tube sheets 6 are arranged passing through this tube sheet 5, and the tips are covered with a cladding layer 2.
heat exchanger tubes made of the same corrosion-resistant metal material welded to
is an outer cylinder fixed to the end face of the body l with bolts 8 so as to surround the heat transfer tube 6.

As is well known, the body part 1 consists of a pair of thin steel plates 10 bent into a semi-cylindrical shape on a single-layer cylinder made of the above-mentioned corrosion-resistant metal material, which serves as a mandrel.
It is manufactured by repeatedly winding it around and vertically welding it, and a built-up layer 11 is welded to the lower end surface to provide rigidity. Part 12 of the inner circumferential corner of the body 1 and tube plate 5
In this example, the entire circumference is sealed and welded using a welding material made of the same corrosion-resistant metal, an annular seal plate 13 is placed thereon, and both ends are further fillet welded around the entire circumference.

An outline of the procedure for forming the tube plate portion of the multi-tubular cylindrical heat exchanger having the above structure will be described below with reference to FIG.

(a) A cladding layer 2 made of a corrosion-resistant metal material is explosively bonded to one side of a flat steel disk 14.

(b) A screw 5a is screwed around the outer periphery of the placing plate 14 made of E, and a heat exchanger tube (not shown) is attached to complete the tube plate 5.

(C) A multilayer cylinder is formed using the above-mentioned known method.

(d) The cladding layer 2 at the end of the multilayer cylinder is peeled off, and the build-up layer 11 is welded to the end face.

(e) While screwing the female thread la into the cladding layer peeled part,
A J-shaped welding groove 15 is machined on the other end surface to complete the body l.

('') The tube plate 5 is screwed onto the body l, the corner part 12 of the body and the tube plate is seal-welded all around the body as described above, and the seal plate 13 is placed on top of the corner part 12 and the whole circumference is Fillet welded,
Finish assembling the tube plate to the body.

In the above step (a), the cladding layer 2 is placed on the flat steel disk 14.
Since the cladding layer 2 is explosively bonded, the cladding layer 2 is metallurgically completely bonded to the M14 base material, and there is no incomplete bonding as in the conventional case. Therefore, the heat exchanger tubes 6 can be arranged on the tube plate 5 without waste, and can be securely fixed by welding to the cladding layer 2, making it possible to make the heat exchanger more compact. In addition, if the base steel is made into a square circumscribing the required disk and the cladding layer 2 is explosively bonded, cladding strength test pieces can be taken from the unnecessary parts at the four corners, and such test pieces In the conventional example, it has been impossible to simultaneously increase the number of plants due to constraints on the shape. In addition, in the above step (c), since the body part l was formed of a multilayer cylinder having an external pressure effect,
In addition to being lightweight and able to withstand high internal pressure, when the end plate 3 is butt welded around the entire circumference to the body l (see Fig. 1, 16), only the end plate portion needs to be annealed, so the performance of the cladding layer 2 is almost unchanged. There is no deterioration and the manufacturing process can be shortened. Furthermore, in the above step (r), the tube sheet 5 and the body part l are screwed together and the corner part 12 is seal-welded, so that the inside of the channel part 17 surrounded by the tube sheet 5, the body part l, and the end plate 3 is There is a risk of high-pressure fluid leaking (and the heat exchanger can be made more compact).

In the above embodiment, the body is formed of a welded multilayer cylinder, but it goes without saying that the multilayer cylinder is not limited to this.

<Effects of the Invention> As is clear from the above explanation, the multi-tubular cylindrical heat exchanger of the present invention has a tube plate made of explosion bonding corrosion-resistant metal clad steel to which a large number of heat transfer tubes are attached, fixed to the body. The body has a cladding layer made of the corrosion-resistant metal material on the inner periphery and is formed of a multilayer cylinder, and the tube plate is a flat disk with a thread on the outer periphery. The heat exchanger tubes are fixed by being screwed into the internal threads provided on the inner circumference of the tube, so the cladding made of a corrosion-resistant metal material of the tube sheet can be completely bonded to the base steel, allowing the heat exchanger tubes to be arranged without waste. It can be joined reliably, improving the quality of the heat exchanger and making it more compact.Also, since the body is made of a multilayer cylinder, there is almost no need for annealing after welding, and there is no deterioration in the performance of corrosion-resistant metal materials due to annealing. , the manufacturing process can be shortened, and since the tube plate and body are screwed together, there is no risk of leaking of the high-pressure fluid inside, making the heat exchanger more compact, making it ideal for heat exchangers that handle high-pressure corrosive fluids. It has a particularly remarkable effect when applied to vessels.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the procedure for forming the heat exchanger of FIG. 1, and FIG.
．． 1 and 6 are vertical sectional views showing a conventional multi-tubular cylindrical heat exchanger, and FIG. - It is an explanatory diagram showing the problem of the heat exchanger of Fig. 1. 11 side part (multilayer cylinder), Ia...Female thread, 2...Crat army, end plate, 5...Tube plate, 5a...-Male thread, 6
Heat exchanger tube, 7...Outer tube, lO/thin steel plate, +1...Build-up layer, 12...Part of corner, 13...Seal plate, 1
4...Flat steel disc, 17. Channel part. Patent applicant: Kobe Steel, Ltd.
Person: Patent attorney, Mr. Hajime and 2 others Figure 1 Figure 1: Figure I43 Figure 4

Claims (1)

[Claims] (1) A multi-tube cylindrical heat exchanger consisting of a tube plate made of clad steel to which a corrosion-resistant metal material is explosively bonded and to which a large number of heat transfer tubes are attached is fixed to a body, in which the body has an inner periphery with It has a cladding layer made of a corrosion-resistant metal material and is formed of a multi-layered cylinder, and the tube sheet is made of a flat disk with a thread on its outer periphery and is screwed into a female thread provided on the inner periphery of the body. A multi-tubular cylindrical heat exchanger characterized by being fixed.