JPH01152400A - High anticorrosion device - Google Patents

Abstract

PURPOSE:To prevent radiation leakage from being emitted into the outside by making a piece of inner piping of high anticorrosion material, a device body of high anticorrosion stainless steel alloy and using a dissimilar metal joint structure at a connecting part. CONSTITUTION:The material of a dissimilar metal joint outside part 6 is the same anticorrosion stainless steel alloy as a device body 1. The material of a dissimilar metal joint inside part 7 is the same high anticorrosion one as a piece of inner piping 2. A dissimilar metal joint 4 is fixed on the device body 1 by both inner and outer faces in order that the joining face of the dissimilar metal joint outside part 6 and the dissimilar metal inside part 6 is positioned in solution 5. The inner piping 2 and an outside supply pipe 3 are joined to form a closed structure. Anticorrosion stainless steel alloy of the dissimilar metal joint part 4 and the thickness of a pipe of a part with which solution come into contact is determined in consideration for corrosion allowance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to highly corrosion resistant equipment such as heaters or coolers for processing highly corrosive solutions.

(Prior art) Conventionally, equipment such as evaporators for highly radioactive waste liquid used in spent nuclear fuel reprocessing equipment has been equipped with an evaporator inside the main body of the equipment, as described in the evaporator of JP-A-57-107201. It has a heating tube, and a heat medium such as high-temperature steam is supplied from the outside to the heating tube to heat the liquid inside the device.In addition, in the case of a cooler, it has a cooling tube inside the device body, A coolant such as water is supplied to the cooling pipe to cool the solution inside the device.

Here, the solution is a highly radioactive, highly concentrated nitric acid solution containing fission products, and especially in the case of a heater, the interior of the heater becomes an extremely corrosive environment due to heating.

In other words, it has been shown that corrosion of structural materials in nitric acid solutions increases as the nitric acid concentration and temperature rise, and it is also clear that corrosion conditions are particularly severe on heat transfer surfaces that come into contact with heating steam pipes, etc. It is being done. For this reason, there have been cases of corrosion in evaporators and the like in previous examples. In order to deal with these problems, the 5 equipment bodies and internal piping are
A corrosion-resistant stainless steel alloy was used, and the wall thickness was designed to allow for corrosion. In addition, in order to eliminate corrosion margins and improve heat transfer efficiency, it is necessary to use materials such as Zr that have higher corrosion resistance, but since the equipment handles highly radioactive solutions, there is a risk of the solution leaking outside. In order to prevent
It is necessary to use a highly corrosion resistant material such as R.

[Problems to be solved by the invention] In the above conventional technology, when the internal piping is made of a corrosion-resistant stainless alloy, the wall thickness must be increased in consideration of the corrosion margin, and the heat transfer efficiency of the internal piping cannot be improved. There was a problem. In addition, in order to reduce the internal pipe wall thickness in order to increase heat transfer efficiency, the pipe is made of a highly corrosion-resistant material such as Zr.

The main body of the device must also be made of the same material, which poses a problem of increasing the cost of the device.

[Means for solving problems]

The solution to the above problem is Zr, which allows the wall thickness of the internal piping to be reduced.
This is achieved by making the device body made of highly corrosion-resistant stainless steel alloy with the required corrosion allowance in mind, and by using a dissimilar material joint structure for the connection part.

[Effect]

The internal piping is made of a highly corrosion-resistant material such as Zr with a small wall thickness, and the solution inside the device is heated or cooled by a coolant such as high-temperature steam or water that passes through the inside. Therefore, it is possible to prevent solution leakage due to corrosion to the hot section piping, and to improve heat transfer efficiency for heating or cooling. By using a dissimilar material joint structure for the connection structure between the internal piping and the main body of the device, they are made of the same material, and a sealed structure can be maintained by welding, etc., so no radioactivity leaks to the outside.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

In FIG. 1, a solution 5 is contained in the highly corrosion-resistant device main body 1, and the internal piping 2 is immersed in the solution 5. A heating material such as high-temperature steam or a cooling material such as water is supplied to the internal pipe 2 from an external supply pipe 3 to heat or cool the solution 5. Here, the material of the highly corrosion-resistant device main body 1 and the external supply pipe 3 is a corrosion-resistant stainless steel alloy, and the plate thickness is determined in consideration of the necessary corrosion margin. The material of the internal pipe 2 is Zr, Ti, T'
It is made of a highly corrosion-resistant material such as i-5% Ta, and has the necessary thickness considering strength and manufacturability.

FIG. 2 is a detailed sectional view showing an embodiment of the A part piping connection part of FIG. 1. In FIG. 2, the dissimilar material joint 4 is made by combining an outer dissimilar material joint 6 and an inner dissimilar material joint 7 by means such as explosive welding, and the material of the dissimilar material joint outer portion 6 is the same corrosion-resistant stainless alloy as the main body 1. The material of the dissimilar joint inner side 7 is the same highly corrosion-resistant material as the internal pipe 2, such as Zr. The dissimilar metal joint part 4 is fixed to the device main body 1 by means such as welding on both the inside and outside surfaces so that the joint surfaces of the dissimilar metal joint outer part 6 and the dissimilar metal joint inner part 7 are located in the solution 5,
The internal pipe 2 and the external supply pipe 3 are similarly joined by means such as welding so that a sealed structure is formed. Here, the wall thickness of the pipe at the portion where the corrosion-resistant stainless steel alloy of the dissimilar material joint 4 comes into contact with the solution is determined to take into account the corrosion margin.

According to this embodiment, the part where the internal piping 2 and the solution 5 come into contact is made of a highly corrosion-resistant material, and the wall thickness of the internal piping 2 can be minimized, and the internal piping wall thickness and the solution can be hermetically isolated. , by ensuring safety by preventing solution leakage, and by using highly corrosion-resistant material for internal piping, where conventional internal piping had to be made thicker to allow for corrosion over the years of use of the equipment, Since the wall thickness can be made thick enough to obtain the necessary strength, heat transfer efficiency can be increased, the equipment can be made lighter and smaller without deterioration of performance, and the dissimilar material joint part 4 can be firmly fixed. There is an effect that can be done.

In addition, some of the wall thicknesses of the dissimilar material joints are increased to prevent corrosion, but since the wall thickness of the tube is only large in only a few areas, this does not result in a reduction in heat transfer efficiency.

FIG. 3 shows another embodiment of the piping connection part shown in part A of FIG.

In Fig. 3, the dissimilar material joint 4 is made by a method such as explosion welding, in which the dissimilar material joint outer part 6 and the dissimilar material joint inner part 7 are made with the outer peripheral surface of the dissimilar material joint inner part 7 as the joint surface 8, and the materials are as described above. This is similar to the embodiment shown in FIG. A flange portion 13 made of corrosion-resistant stainless steel is provided on the outer periphery of the dissimilar material joint 4.
The flange end and the main body 1 of the device are fixed by means such as welding, and the internal piping 2 and the external supply pipe 3 are joined by means such as welding, thereby sealing the internal piping and the solution to form a new structure.

According to this embodiment, the same effects as the above-described embodiment shown in FIG. 2 can be obtained. In addition, this method has the effect of increasing the area of the joint surface 8 of dissimilar materials.

FIG. 4 shows another embodiment of the piping connection part shown in part A of FIG.

In FIG. 4, the dissimilar material joint part 4 connects the dissimilar material joint outer part 6 and the dissimilar material joint inner part 7, and connects the outer peripheral surface of the dissimilar material joint membrane inner part 7 to the joint surface 8.
The material is the same as that of the embodiment shown in FIG. 2 described above. Dissimilar material joint part 4
is fixed to the device body 1 by means such as welding, and the internal piping 2
It is then joined to the external supply pipe 3 by means such as welding, and the internal pipe and solution are sealed to form a new structure.

According to this embodiment, the same effects as the embodiment shown in FIG. 3 described above can be obtained.

FIG. 5 shows another embodiment of the piping connection section A in FIG. 1. In FIG. 5, the dissimilar material joint section 9 consists of a dissimilar material joint outer section 10 and a dissimilar material joint inner section 11, and is manufactured by means such as explosive welding. As for the material, the outer part 10 of the dissimilar joint is made of corrosion-resistant stainless steel alloy.

The dissimilar material joint inner part 11 is made of a highly corrosion-resistant material such as Zr, and the dissimilar material joint part 9 is fixed to the device main body 1 using the same material by means such as welding to form a sealed structure. The dissimilar material joint 4 has a structure similar to that described in the embodiment shown in FIG. 2 above. Here, the joint surface 8 of the dissimilar material joint 4 is the joint surface 1 of the dissimilar material joint 9.
2, and fix the dissimilar material joint outer part 10, the dissimilar material joint outer part 6, and the dissimilar material joint inner part 11, and the dissimilar material joint inner part 7 to form a hermetically sealed structure by means such as welding.

The internal pipe 2 and the external supply pipe 3 are connected to the dissimilar material joint 4 in the same manner as described in FIG.

According to this embodiment, in addition to the effects described in the example of FIG. 2 above, all the contact surfaces between the internal piping and the solution can be made of highly corrosion-resistant materials, so there is an effect that the corrosion resistance of the internal piping can be further improved.

Other embodiments of the present invention are shown in FIGS. 6 and 7. 6th
In the figure, a portion 14 of the device body 1 that comes into contact with a solution in a severe corrosive environment and the internal piping 2 are made of a highly corrosion-resistant material such as Zr, and a portion 15 of the device body 1 that does not come into contact with the solution.
The material is a corrosion-resistant stainless steel alloy. Here, between the highly corrosion-resistant material part 14 and the corrosion-resistant stainless steel alloy part 15 of the main body of one device, and between the internal piping 2 and the external supply pipe 3, a highly corrosion-resistant material such as Zr and corrosion-resistant stainless steel manufactured by means such as explosion bonding are used. The dissimilar material joints 16 and 17 made of alloy are used to join and fix the respective parts made of the same material by a method such as welding to form a sealed structure.

Here, the plate thickness of the highly corrosion-resistant material portion 14 of the device body is a thickness that takes into consideration the strength and manufacturability of the device body, and the plate thickness of the corrosion-resistant stainless steel alloy portion 15 of the device body is determined by considering only the corrosion margin of the gas phase portion of the solution. The plate thickness is as follows.

According to this embodiment, the entire device including the piping can be configured with the minimum plate thickness, and high corrosion resistance and weight reduction can be achieved in one device.

Furthermore, the cost can be reduced compared to when the entire device is made of a highly corrosion-resistant material.

Other embodiments of the present invention are shown in FIGS. 8 and 9. In this embodiment, an external jacket 18 for heating or cooling is provided on the outer surface of the highly corrosion resistant material portion 15 of the highly corrosion resistant equipment shown in FIG. 6.

According to the present invention, heat can be transferred from the external jacket 18 to the internal solution 5 of the device main body 1, so that the efficiency of heating or cooling one device can be further improved. Further, by using highly corrosion-resistant materials, external heating or cooling can be performed through the minimum plate thickness, thereby improving heat transfer efficiency. Furthermore, in the case of a heater, the heat transfer surface, which is subjected to a severe corrosive environment, is made of a highly corrosion-resistant material, which is particularly effective in terms of corrosion resistance.

FIG. 10 shows another embodiment of the present invention. In FIG. 10, the device main body 1 includes heat transfer tubes 2 and a tube plate 19 for heat transfer.
This evaporator has a tube-tube plate section 20 consisting of a tube plate section 20, and supplies the heating material of the heating steam tube to the outer surface side of the heat transfer tube 21 from the external supply tube 3 to heat and boil the solution 5 inside. In FIG. 10, a tube-tube plate section 2 consisting of a heat transfer tube 21 and upper and lower tube plates 19 is shown.
The material of 0 is a highly corrosion resistant material such as Zr, Ti, Ti-5% Ta. The material of the upper and lower parts 1 of the device body is a corrosion-resistant stainless steel alloy. Zr, Ti, Ti-5 manufactured by explosion bonding etc. are used at the connection part between the M device main body 1 and the tube-tube plate part 20.
Through a dissimilar material joint 16 made of a highly corrosion-resistant material such as %Ta and a corrosion-resistant stainless alloy, parts of the same material are joined and fixed by means such as welding to form a sealed structure. External supply pipe 3 and the pipe
Similarly, a dissimilar material joint 17 is used to join the tube plate portion 20.

According to this embodiment, only the heat transfer tube portion of the device main body 1 having the heat transfer surface subjected to the most severe corrosive environment can be made of high-grade material, which has the effect of reducing the cost of the device. Furthermore, the thickness of the heat transfer tube can be minimized, increasing the heat transfer effect.

This has the effect of making the device lighter and smaller without deteriorating its performance.

In the dissimilar material joints of highly corrosion resistant equipment shown in Figs. 1 to 10, the dissimilar material joints are made by explosion bonding of highly corrosion resistant materials such as Zr, Ti, Ti-5% Ta, etc. and corrosion resistant stainless alloys using Ta as an intermediate material. If so, it is possible to realize highly corrosion-resistant equipment that has particularly excellent performance in terms of strength, corrosion resistance, etc.

〔Effect of the invention〕

According to the present invention, only the parts such as internal piping, which are exposed to a particularly severe corrosive environment, are made of highly corrosion-resistant material such as Zr, so the cost of the equipment can be reduced compared to the case where the entire equipment is made of highly corrosion-resistant material. In addition, the wall thickness of heat transfer parts such as internal piping and external jackets can be kept to a minimum without considering corrosion sills, so assuming that the thermal conductivity is the same, the wall thickness can be reduced to about 1
/2, the temperature drop due to heat transfer can be reduced to 1/2, and an improvement in thermal efficiency of about 10% can be expected. or.

Since the outer diameter can be made thinner while keeping the inner diameter the same, it is possible to increase the number of heat exchanger tubes in the same volume, making it possible to make the equipment smaller and lighter. The outer diameter of the coil is 1 compared to the conventional one.
0%, the volume reduction is about 20%, and the coil surface area within the same volume can be increased by 20%.6 or more effects are obtained in the present invention.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a highly corrosion-resistant device showing an embodiment of the present invention, FIGS. 2 to 5 are detailed views of the part A in FIG. 1, and FIG.
8 and 10 are longitudinal cross-sectional views of highly corrosion-resistant equipment showing other embodiments of the present invention, and FIG. 7 is a detailed view of part A in FIG. 6.
FIG. 9 is a detailed view of the section shown in FIG. 8. 1... Highly corrosion resistant equipment body, 2... Internal piping, 3...
- External supply pipe, 4... Dissimilar material joint, 5... Solution, 6
... Dissimilar material joint outer part, 7... Dissimilar material joint inner part, 8.
...joint surface. 9... Dissimilar material joint part, 10... Dissimilar material joint outer part, 11
... Inner side of dissimilar material joint, 12... Joint surface, 13...
Flange part, 14...Device body solution contact part, 15...
・Device main body solution non-contact part, 16... Dissimilar material joint, 17.
...Dissimilar material joints. 18...External jacket, 19...Tube plate, 20...
- Pipe-tube plate section, 21... heat exchanger tube.

Claims (1)

[Scope of Claims] 1. Highly corrosion-resistant equipment such as a heater or cooler for treating highly corrosive solutions, which consists of an equipment body, internal piping, and external supply pipe, in which the equipment body is made of a corrosion-resistant stainless steel alloy, and the internal piping is made of a corrosion-resistant stainless steel alloy. The material is a highly corrosion-resistant material such as Zr, Ti, Ti-5%Ta, etc., a dissimilar material joint made of both materials is interposed between the internal piping and the external supply pipe, and the piping and the dissimilar material joint are welded at the same material part. The corrosion-resistant stainless steel alloy part of the dissimilar metal joint is joined and fixed by welding to the equipment body can wall made of corrosion-resistant stainless alloy in such a way that a sealed structure is formed. Highly corrosion resistant equipment. 2. The wall thickness on the external supply pipe side of the dissimilar metal joint is made thick enough to allow for some corrosion, the dissimilar metal joint surface is placed in the solution, and the corrosion-resistant stainless steel part of the dissimilar metal joint is placed on the inner and outer surfaces of the equipment body. Claim 1, characterized in that the device is joined and fixed to the main body of the device by welding to form a sealed structure.
Highly corrosion resistant equipment as described in section. 3. The dissimilar material joint has a part of the outer circumferential surface on the internal piping side of the dissimilar material joint and a part of the inner circumferential surface of the dissimilar material joint on the external supply pipe side, and the outer periphery of the dissimilar material joint on the external supply pipe side. A patent characterized in that a flange portion made of a corrosion-resistant stainless alloy is provided in the section, and the end face of the flange portion and the device body are joined and fixed by a method that forms a sealed structure by welding to the device body on both the inside and outside of the device body. A highly corrosion resistant device according to claim 1. 4. In the dissimilar material joint, the outer peripheral surface of the dissimilar material joint on the internal piping side and the inner peripheral surface of the dissimilar material joint on the external supply pipe side are the dissimilar material joining surfaces, and both end surfaces of the dissimilar material joint on the internal piping side are the main body of the device. A sealed structure is formed by welding the outer peripheral surface of the dissimilar metal joint made of a corrosion-resistant stainless alloy and the device body on both the inside and outside of the thickness of the device body. 2. The highly corrosion-resistant device according to claim 1, wherein the device is joined and fixed by a method described in the above. 5. Position the dissimilar material joint part on the outer periphery of the pipe portion of the dissimilar material joint part so that the dissimilar material joining surfaces of the two dissimilar material joint parts coincide with each other, and the dissimilar material joint part The parts made of the same material are joined by a method such as welding that forms a sealed structure, and the end face of the highly corrosion-resistant stainless alloy part of the disc-shaped dissimilar metal joint and the device body are joined at the inner and outer surfaces of the device body's plate thickness. 2. The highly corrosion-resistant device according to claim 1, wherein the device is joined and fixed by welding to form a sealed structure. 6. In highly corrosion-resistant equipment consisting of the equipment body, internal piping, and external supply pipe, the material of the parts of the equipment body including the area that comes into contact with the solution and the internal piping is Zr, Ti, Ti-5%T.
The parts of the equipment body that do not come in contact with the solution are made of corrosion-resistant stainless steel alloy, and the parts of the equipment body that are made of highly corrosion-resistant material and the parts that are made of corrosion-resistant stainless steel alloy, and between the internal piping and external supply pipe. A highly corrosion-resistant device, characterized in that the dissimilar material joint, the device main body, and piping are joined and fixed via a dissimilar material joint made of a highly corrosion-resistant material and a corrosion-resistant stainless steel alloy in such a manner that a sealed structure is formed by welding the parts of the same material. 7. Claim 6, characterized in that the device has a jacket for heating or cooling on the outer surface of the device body.
Highly corrosion resistant equipment as described in section. 8. In a highly corrosion-resistant device consisting of a device main body, an internal heat transfer tube, and an external supply pipe, the material of the tube-tube plate portion having the internal heat transfer tube and tube sheet is a highly corrosion-resistant material such as Zr, Ti, Ti-5% Ta, etc. The equipment body and external supply pipe are made of corrosion-resistant stainless steel alloy, and a dissimilar material joint made of highly corrosion-resistant materials such as Zr, Ti, Ti-5% Ta, etc., and corrosion-resistant stainless steel alloy is used between the tube-tube plate portion, the equipment body, and the external supply pipe. A highly corrosion-resistant device, characterized in that the dissimilar material joint, the main body of the device, the external supply pipe, and the tube-tube sheet portion are joined and fixed in the same material portion by means such as welding that forms a sealed structure. 9. Zr, Ti, T using Ta as an intermediate material in the joint of dissimilar materials
9. A highly corrosion-resistant device according to claim 8, characterized in that a dissimilar material joint is manufactured by explosively joining a highly corrosion-resistant material such as i-5% Ta and a corrosion-resistant stainless steel alloy.