JPS59184896A - Partition room structure of waste gas preheater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] This invention relates to a partition structure of an exhaust gas preheater installed in a gaseous waste treatment system of a nuclear power plant, and in particular, to a structure of a partition chamber body plate. This invention relates to a partition structure of an exhaust gas preheater in which one end is welded and sealed to a tube plate of a heat exchanger body shell plate, and a lid is provided at the other end via a sealing means to facilitate maintenance.

[Prior art]

At nuclear power plants, the treatment of radioactive materials is strictly controlled. For example, in the radioactive gaseous waste treatment system, an exhaust gas preheater is installed to avoid adverse effects on the catalyst in the exhaust gas recombiner of the same system equipment. It is designed to prevent water droplets from forming.

Therefore, the structure of the conventional exhaust gas preheater will be explained based on FIG. The exhaust gas enters through the exhaust gas inlet nozzle 3 of the partition body plate 2, flows inside the heat transfer tube 5 in the body plate 4, and exits through the exhaust gas outlet nozzle 6, while the heated steam enters the exhaust gas inlet nozzle 3 of the partition chamber body plate 2. 7, the exhaust gas flowing through the heat transfer tube 5 is heated to a temperature higher than the saturation temperature of steam to prevent water droplets from being entrained in the exhaust gas, and the exhaust gas is turned into condensate and exits through the condensate outlet nozzle 8. There is.

The connection between the partition chamber body plate 2 and the fuselage body plate 4 is made through the tube plate 9, and inspection and repair of the inside of the partition plate chamber, the exhaust gas side of the tube plate 9, and the heat exchanger tubes 5 is performed. Therefore, the fuselage flange 1o is integrally welded to the fuselage body plate 4, the partition flange 11 is integrally welded to the partition chamber body plate 2, and the tube plate 9 is sandwiched and the three plates are tightened together using bolts. It is.

By the way, exhaust gas is a fluid with radioactivity of 1 μμci/cc or more, and it is essential to prevent its leakage. Therefore, the exhaust gas inlet nozzle 3 and the exhaust gas outlet nozzle 6
The shape of the joint between the pipe and the connecting pipe is butt welded to prevent sealing, and the tube plate 9 and the partition flange 11 are attached by lip seal welding 12 to ensure airtightness. ing.

Note that a partition plate 14 is welded and fixed between the hemispherical steel plate 13 of the partition chamber body plate 2 and the tube plate 9 by appropriate means.

Although the above structural designs are designed to improve maintainability and prevent leakage, both have problems that are contradictory to each other.

That is, as shown in the first section, since the tube plate 9 has a structure in which three sheets are fastened together, the sealing performance is insufficient, and especially on the shell side where lip seal welding is not performed, there is a risk of leakage of heated steam. There is a problem in which the risk of leakage cannot be completely avoided, such as a risk of serious danger.

Second, when inspecting or repairing the partition chamber, the exhaust gas side of the tube plate 9, and the heat transfer tubes 5, the lip seal weld 12 is removed with a grinder while the bolts 15 are still attached, and then Maintenance is only possible after cutting the butt bath junctions between the exhaust gas inlet nozzle 3 and the exhaust gas outlet nozzle 6 and the connecting piping, and then removing the entire partition.

Therefore, the maintenance requires a large number of man-hours, is very cumbersome, and is difficult to perform.

Therefore, it has been desired to develop and improve drastic structural measures that can solve the problem of improving maintainability and preventing leakage without contradicting each other, and can sufficiently achieve both functions.

[Purpose of the invention]

The purpose of this invention is to solve the problems of the exhaust gas preheater based on the above-mentioned conventional technology as a technical problem, and to improve maintainability and ensure leakage prevention without contradicting each other. The present invention provides an excellent exhaust gas preheater compartment structure that is beneficial to the field of nuclear reactor applications in the energy industry.

[Summary of the invention]

In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims in accordance with the above-mentioned object, is to directly connect the proximal end of the fuselage shell plate and the tube plate, and the tube plate and one end of the partition shell plate. In addition to connecting and connecting by welding, a flange is provided at the end of the partition chamber body plate, a flat cover 15 is attached, a partition plate is welded between the flat cover and the tube plate, and the 7 lunges and the flat cover are welded. Attach the diaphragm to the flange provided at the end of the body plate of the partition chamber by welding the seal lip, or by welding the diaphragm to the flange provided at the end of the body plate of the partition chamber, and install a partition cover inside the partition chamber and insert a partition plate between the partition cover and the tube plate. By welding, it is possible to obtain high reliability in preventing leakage of exhaust gas, and at the same time, it is a technical measure that improves maintainability.

[Embodiments of the invention]

Next, embodiments of the present invention will be described based on the drawings from FIG. 3 onwards. Note that the same parts as in FIGS. 1 and 2 will be described using the same reference numerals.

In the embodiment shown in Fig. 3.4, the base end of the fuselage shell plate 4 and the tube plate 9, and the tube plate 9 and one end of the partition body plate 2 are joined by direct welding with the tube plate 9 in between. The joints are made to be in contact.

Therefore, there is no risk of exhaust gas or heated steam leaking from any of these parts.

Further, seven flange 16 is formed in advance on the other end of the partition body plate 2, and a flat cover 17 is attached via a bold 15 to facilitate maintenance.

In order to prevent exhaust gas from leaking from this part, the diaphragm 16 is directly attached to the flange 16 by welding.

Therefore, as with the tube plate portion 9, there is no risk of exhaust gas leaking.

Therefore, since the partition plate 14' cannot be attached directly to the diaphragm 18 due to mechanical reasons, the partition plate 14' cannot be attached directly to the diaphragm 18.
is attached to the bracket 20 provided inside the partition chamber body plate 2, one end is fixed to the tube plate 19 with a bolt 21, and the other end is welded to the tube plate 9, and the inlet side and outlet side are fixed. Try to separate it.

In the above configuration, the exhaust gas entering through the exhaust gas inlet nozzle 3 flows through the heat exchanger tube 5, undergoes heat exchange with steam, is heated to a temperature higher than the saturated steam pressure, is prevented from entraining water droplets, and is discharged from the exhaust gas outlet nozzle 4. Ru.

Therefore, inside the partition room, the exhaust gas side tube plate 9 surface, and the heat exchanger tube 5
When performing inspection or repair maintenance, first remove the bolts 15, remove the flat cover 17, and then remove the diaphragm 18, which is attached by welding to the partition flange 16.
As shown in FIG. 4, a well-known diaphragm cutter 22 is used.
The arm 23 is fixed to the flange 16 of the partition body plate 2 via the spacer bush 24 with bolts 25,
The mokyu 26 is rotated, the arm 27 rotates the vine 28, and the welded part is cut and removed by the machine 4,1.

Next, remove the bolts 15 and remove the hinge cover 19.

Maintenance is possible only with the above work. Therefore, the exhaust gas inlet nozzle 3 and the exhaust gas outlet nozzle 6
It is not necessary to remove the entire partition where the butt weld between the pipe and the fitting pipe is cut.

According to the above-described embodiment, it is possible to obtain high reliability in preventing leakage of exhaust gas, and also to obtain an effect of excellent maintainability.

Next, in the embodiment shown in FIG. 5, a diaphragm is provided in the partition chamber 7 and the flange 1 in order to prevent exhaust gas leakage as in the above-mentioned embodiment.
6 and the flat lid 17 are attached by applying lip seal welding 12 to the parts, and the partition plate 14 is directly attached to the flat lid 17 and the tube plate 9 using the same conventional technique.

In this embodiment as well, airtightness can be maintained as in the previous embodiment.

In addition, when inspecting and repairing the exhaust gas side of the tube plate 9 and the heat exchanger tubes 5 in the partition room, first remove the bolts 15, then scrape off the lip seal welds 12 with a grinder.
Remove 17.

By doing this, as in the previous embodiment, there is no need to cut the butt welds between the exhaust gas inlet nozzle 3 and the exhaust gas outlet nozzle 6 and the connecting pipe and remove the entire partition, making maintenance possible. , there is no substantial change in the action or effect).

〔Effect of the invention〕

As described above, according to the present invention, it is possible to basically prevent the leakage of exhaust gas and heated steam in the exhaust gas preheater with high reliability, and the excellent effect of improving maintainability is achieved. .

Furthermore, by directly welding one end of the partition chamber body plate and the body body plate to the tube plate, the sealing performance is extremely excellent, which contributes to safety.

Since the other end of the partition chamber body plate is also joined to the flat lid via the welded diaphragm and lip seal bath, the four welded joints are separated into left and right sides, which has the effect of improving sealing performance accordingly.

Since the flat cover can be removed and the welded portion removed using a grinder or the like, there is no need to remove the exhaust gas inlet/outlet valve, thereby providing an excellent effect of easy maintenance.

In addition, since the welded parts are separated, the structure is simple, easy to manufacture, and easy to handle and manage, making it an excellent radioactive gas processing device.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory sectional view showing the entire exhaust gas preheater according to the prior art, FIG. 2 is an enlarged sectional view of the partition shown in FIG. 1,
FIG. 3 is a cross-sectional view explaining the structure of a partition according to one embodiment of the present invention, FIG. 4 is a cross-sectional view explaining the insertion state of the diaphragm force lever, and FIG. 5 is a cross-sectional view showing the structure of the partition according to another embodiment. be.

Claims (1)

[Claims] 1. A partition chamber body plate having a partition plate inside and an exhaust gas inlet nozzle and an exhaust gas outlet nozzle is joined to a body body plate having a heat exchanger tube inside and a heating steam mechanical nozzle and a condensate outlet nozzle through a tube plate by a sealing means. In the partition structure of an exhaust gas preheater, one end of the partition body plate is welded to the tube plate, and a flat cover is connected to the other end, and the flat cover and the partition body are connected to each other by welding. An exhaust gas preheater characterized in that a sealing means is interposed between the plate and the plate.