JPS5953089B2 - Reactor for radiation irradiation exhaust gas treatment - Window foil replacement method for entrance window - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present inventors have invented an exhaust gas treatment method characterized by aerosolizing SO2 and/or NOx in exhaust gas due to radiation irradiation, and various improvements thereof, and have separately filed a patent application for the method.

According to this method, SO2 and NOx in exhaust gas can be removed simultaneously with high efficiency.

In this case, the radiation entrance surface (incidence window) of the container used to irradiate the exhaust gas with radiation (reactor for radiation irradiation exhaust gas treatment) is designed to prevent energy loss during the passage of radiation, with the purpose of blocking the inside and outside of the reactor. A thin metal film (Ti, SUS, etc. with a thickness of several tens of microns) is often used.

That is the entrance window window foil. This entrance window window foil is exposed to the exhaust gas inside the reactor while the radiation passes through it.
Therefore, there is heat generation due to energy loss when radiation passes, dust and highly corrosive substances in exhaust gas (dust, SOX, NOx, etc. contained in small amounts in exhaust gas, reaction products including aerosols generated by radiation irradiation, etc.) As a result of exposure to water, condensation, etc. are often added to the product, making it extremely susceptible to damage.

For this reason, the inventors of the present invention have devised a method for protecting an entrance window foil and have already filed a separate application as a method for improving the entrance window of a reactor for treating radiation irradiated exhaust gas, but the method has not been sufficient.

This invention is a method for preventing damage to the window foil, which replaces the entrance window foil in a short time by remote control while maintaining the insulation between the inside and outside of the beam actor. The aim is to enable continuous operation during the period and to simplify the work of replacing window foil.

Conventionally, the entrance window foil was simply installed by being sandwiched between flanges provided on the reactor, and there was no problem in replacing it by stopping the flow of exhaust gas inside the reactor and blocking the inside and outside of the reactor. I had to do it after that.

In addition, since the replacement work was done manually, it was necessary to properly ventilate and purify the room where the irradiation equipment was located (irradiation room) as a work environment, and to shut down or shield the radiation source. .

Moreover, for replacement work, it is necessary to move the reactor or the main body of the radiation source and its auxiliary equipment, and as the equipment becomes larger, the amount of work and time is rapidly increasing. Ta.

Incidentally, exhaust gas treatment equipment is often required to have long continuous operation and short downtime.

However, in the conventional technology, this is done using the method described above.
This has disadvantages such as requiring sophisticated incidental equipment and restricting the radiation irradiation conditions, and still cannot provide complete guarantees.

In order to deal with this problem regarding window foils, the present inventors have researched a method for replacing window foils without interfering with the operation of exhaust gas generating facilities, and have arrived at the present invention.

As a result of examining the points that the window foil replacement method should have, the following two conditions were found.

1. When replacing the window foil, do not damage the insulation inside and outside the reactor.

This is because there is normally a pressure difference between the inside and outside of the reactor, so when the shutoff is removed, a large amount of gas may flow in or out, or corrosive substances inside the reactor, such as dust, may diffuse outside the reactor and cause various problems. This is because there is a risk of causing an accident.

2. It must be possible to replace it in a short time or by remote control.

This is because, as an exhaust gas treatment facility, stopping operation for a long time when replacing window foil is a problem that must be avoided as much as possible as a pollution prevention device.

Another reason is that when replacing while irradiating radiation, it is necessary to use remote control because people cannot get close to it.

As a first specific example, a replacement window foil replacement method will be described below.

Figure 1 is a conceptual diagram of this, showing how the used window set A installed in the reactor entrance window B is being pushed out and being replaced by a new window set A. In the figure, 〈〉 is the moving direction of the window set.

As is clear from the diagram, there are two sets of new and old windows for the reactor entrance window being replaced: L-A, A? 2. Therefore, the isolation between inside and outside is maintained.

Because parts of the window set other than the window foil enter the entrance window, radiation irradiation must be stopped during replacement.

Here, by simply preparing and loading several window sets in advance, a supply device is used to supply the used window sets one after another to the positions required for the replacement operation shown in Figure 1, and the used window sets created by the replacement operation shown in Figure 1 are used. Another storage device is required to store them one after another in a predetermined position.

If it is linked to the operation shown in Figure 1 and is automatically supplied and stored, the first
All replacement work can be done just by following the instructions shown in the diagram.

Replacement can be done by determining a fixed period of use close to the life of the window foil, or by detecting signs of breakage of the entrance window foil, and by incorporating these methods, fully automatic operation is possible.

Loading of window sets and collection of used window sets can be done in the irradiation room during regular maintenance of equipment that generates exhaust gas, but window sets that are loaded depending on the continuous operation time until the next regular maintenance are carried out. It is necessary to decide the number of

However, this does not apply when these are performed outside the irradiation room.

For more detailed explanation, FIG. 2 shows a specific example of a cross section of the entrance window perpendicular to the axis of movement of the window set.

The window set is composed of a window foil support E, a gasket G, and a window foil H secured by bolts to a window foil holding flange B.

This can be moved between the gasket F and the window set holder C attached to the actor-θ.

The window set is held down by the window set holder by the force indicated by the arrow in the figure, and is brought into close contact with the reactor by the action of the packing, and is used as the entrance window foil.

To replace the window set, the force indicated by the arrow in the figure is weakened to some extent to make the window set movable, and the operation shown in FIG. 1 is performed.

During replacement, some leakage is expected from the contact surfaces of the old and new cassettes, and between the window set and the window set gasket.

Unless the amount is particularly large, there will be no problem as long as the pressure inside the reactor is negative compared to the outside, and this can be prevented by considering a seal on the side of the window set.

The portion of the window set other than the window foil corresponds to the window foil support device set forth in the claims.

The second specific example shows roll-up window foil replacement.

FIG. 3 is a conceptual diagram thereof, in which the window foil at the reactor entrance window A is part of the window foil ribbon B that continues from the roll C before use to the roll C used.

Therefore, the window foil is replaced by winding it up on a used roll and letting it out from the roll before use.

The arrow in the figure indicates the direction of movement of the window foil.

However, since the window foil alone is insufficient, it is necessary to reinforce it with a ring-shaped binder 4F, etc., to withstand the pressure difference inside and outside the reactor and the movement of the window foil.

Further, a roll DD is used to seal the end of the entrance window in the moving direction.

As for this binder, it is not necessary to use a ring-shaped binder if a similar binder is bonded to the window foil ribbon in advance.

In the case of this method, since nothing other than the window foil is placed in the entrance window, it is also possible to replace the window foil before irradiating the radiation.

The method for collecting used window foil and loading window foil before use is the same as for the replacement set, and the length of the window foil ribbon should be considered instead of the number of window foils in the window set.

For a more detailed explanation, FIG. 4 shows a specific example of a cross section of the entrance window perpendicular to the axis of movement of the window foil.

Both ends of the window foil ribbon E are supported so as to be sandwiched between an upper binder θ having holes and a lower binder F having a matching convex portion, and the holes and the convex portions engage with each other.
It is designed to stay in place as long as you stay away from it.

Therefore, a portion of the binder of the window foil is pressed in the direction of the arrow by the window foil presser A, and the window foil is brought into close contact with the reactor C via the seal B.

The upper binder has a protrusion that catches on the window foil holder to prevent it from shifting laterally in the figure.

In order to promote close contact between the window foil and the binder, it is also effective to coat the binder or window foil surface in that area with an elastic thin film or apply a viscous liquid.

The window foil can be moved while maintaining its adhesion by pulling the binder apart.

It is preferable to divide the window foil presser into several parts in the direction of the axis of movement to equalize the pressing force, and if the binder is given a certain degree of rigidity, there is no need to apply the window foil presser to the entire surface.

It will be necessary to consider a method of fixing the window foil presser to prevent it from shifting when the window foil moves.

In order to further explain the sealing roll part shown in FIG. 3, FIG. 5 shows a cross section of the sealing roll part parallel to the axis of movement of the window foil.

The window foil B is tightly attached to the reactor D by the sealing roll A through the packing C with the force indicated by the arrow 1.

Therefore, the movement of the window foil in the direction of the arrow - is carried out by the rotation of the roll → without rubbing against the roll, and the airtightness is maintained.

At the opposite end of the entrance window, it may be necessary to take measures to remove deposits from the surface facing the window foil reactor.

Note that the upper and lower binders correspond to the window foil support device described in the claims.

As described above, according to this method, it is possible to replace the window foil remotely or in a short time, and it is also possible to maintain isolation between the inside and outside of the reactor at the time of replacement.

From now on, it will be possible to replace window foils without interfering with the operation of the exhaust gas generating source, and in addition to responding to accidents where window foils are damaged, it is now possible to prevent window foil damage itself by replacing it regularly.

Therefore, it can be said that the problem of damage to the entrance window foil has been solved.

This is significant in that it solves the problems of limiting continuous operation time and window foil replacement work, which were problems in treating radiation irradiation exhaust gas, and paving the way for practical application.

Therefore, we were able to make a significant contribution to exhaust gas treatment technology.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a window foil replacement method using the method of replacing the entrance window of a reactor for treating irradiated exhaust gas according to the method of the present invention. In the figure, A (solid line square) represents the new window set being installed, A' (solid line square) represents the used window set to be replaced, and B (dashed line square) represents the beam actor entrance window. FIG. 2 shows a specific example of the entrance window cross section perpendicular to the window set movement axis of the reactor entrance window. In the figure, A is the window foil press bolt; B is the window foil press flange; C is the bad set press; D is the reactor; (A・B-E-G-
H is window set), E is window foil support; F is packing for window set; G is packing for window foil; H is window foil; (A-B-
E-G represent the window foil support device), respectively. FIG. 3 is a conceptual diagram when the method of the present invention is implemented by a winding method. In the figure, A (broken line square) is the beam actor entrance window, B is the window foil ribbon, C is the window foil roll before use, C' is the used window foil roll, D and D' are the sealing rolls, and E and E' are the windows. The binder on the foil, F and F' represent the binder under the window foil, respectively. FIG. 4 shows an example of a sectional view of the entrance window when the method of the present invention is carried out by the winding method. In the diagram, A is a window foil presser, B is a seal, C is a reactor, and D
represents the window foil upper binder, E represents the window foil ribbon, F represents the window foil lower binder, (D-F represents the window foil support device), respectively. FIG. 5 shows a cross-sectional view of a retractable sealing roll when the method of the present invention is carried out in a retractable manner. In the figure, A represents a sealing roll, B represents a window foil, C represents a packing, and D represents a reactor.

Claims (1)

[Scope of Claims] 1. As a window foil for the irradiation window of a reactor for irradiation exhaust gas treatment, a connected body in which window foils for at least two times are connected or a continuous body having a continuous length that can be used for at least two times. When using a multi-use integrated window foil in either configuration and replacing the used window foil with a new window foil, the used window foil is moved parallel to the plane containing the reactor entrance window. By replacing the old and new window foils while ensuring that the actuator-inlet window opening is immediately covered by the new window foil, the used window foil can be removed without substantially compromising the insulation inside and outside the reactor. A window foil replacement method for an entrance window of a reactor for radiation irradiation exhaust gas treatment, characterized by replacing the foil with a new window foil. 2. The method according to claim 1, characterized in that the window foil is moved together with a window foil support device. The method according to claim 1 or 2, characterized in that a connected window set in which 32 or more window sets are connected in series in the direction of movement is used. 4. The method according to claim 1 or 2, characterized in that a continuous window foil wound into a roll is used. 5. The method according to any one of claims 1 to 4, characterized in that the window foil is moved by remote control to replace the input window foil in a short time while maintaining isolation between the inside and outside of the reactor. .