JP2000180592A - Radioactive gas purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve work efficiency by easily purifying-processing radioactive gas in objective components where an opening is provided at one location. SOLUTION: Inside an inner casing 1, a filter 3, an air cooler 4, a suction fan 5 and a fan motor 6 are arranged in the order of gas flow direction. An air intake nozzle 7 is connected at the inlet of the inner casing 1. Surrounding the inner casing 1, an outer casing 2 is concentrically provided. A suction nozzle 7 and an exhaust nozzle 8 are concentrically connected to the outer casing 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive gas purifier for removing radioactive substances and the like contained in gas at a nuclear power plant or the like.

[0002]

2. Description of the Related Art Conventionally, in the case of removing radioactive substances and the like contained in gas in a device such as a container such as a tank or a large device having a space in the device, a duct is connected to the device and the inside of the device is removed. Gas is sucked by a so-called filter unit combining a suction fan and a filter to remove a target substance and purify the gas. Then, the gas after the purification treatment is once released to the inside of the building, or is connected to a ventilation air-conditioning system of the building and connected to a duct to be discharged to the outside of the building.

However, when a small amount of radioactive material or the like passing through the filter is unacceptable, or when the gas inside is not air and cannot be released into the atmosphere, etc.
A method of returning the gas after the purification process to the inside of the processing target device again,
That is, a circulation purification method having a circulation system is employed.

In the case of the circulating purification method, the equipment to be treated needs an opening for taking out the gas inside and an opening for returning the gas after purification into the equipment. Usually, two openings communicating with the internal space of the equipment are required. In this method, the gas to be treated is released from one side, and the gas after purification is returned to the other side.

[0005]

In the conventional circulating purification treatment method, when an apparatus having only one opening or another opening cannot be used, two openings, one for taking out and the other for returning, are used in one opening.
It is necessary to connect the book duct.

In this case, it is necessary to take measures such as filling a gap between the two ducts, and when the opening area is small, there is a problem that a sufficient air volume cannot be obtained and ventilation efficiency is reduced. . In addition, since each of these methods uses two ducts, there is a problem that the work of laying and removing the ducts increases, and the occupation ratio of the ducts in the work area around the equipment increases, thereby lowering the work efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The gas inside a device having only one opening to be purified is sucked into a filter unit, and the gas purified by the filter unit is re-purified. An object of the present invention is to provide a radioactive gas purifying apparatus capable of performing efficient circulation purification using only one opening of a device by using only one duct for returning the device to the inside of the device.

[0008]

The invention according to claim 1 includes a filter for removing radioactive substances and the like in a gas, an intake fan for sucking a gas to be purified, and a fan motor for driving the intake fan. An internal casing having an intake nozzle for taking in the gas to be purified, and an external casing having an exhaust nozzle that covers the internal casing, receives the purified gas discharged from the internal casing, and guides the gas to the outside. And

According to the present invention, the internal casing and the external casing are separated, and the internal casing is provided with an intake nozzle for taking in the gas, and the filter, the intake fan and the fan motor incorporated in the internal casing are used to suction and exhaust the gas. The radioactive substances and the like in the inside are removed, and the purified gas is once discharged from the inner casing to the outer casing surrounding the inner casing, and then exhausted from an exhaust nozzle corresponding to an outlet of the outer casing. As a result, it is possible to widen the options for the arrangement of the intake nozzle and the exhaust nozzle.

According to a second aspect of the present invention, in order to integrate the intake nozzle of the inner casing and the exhaust nozzle of the outer casing, the intake nozzle is located inside and the intake nozzle and the exhaust nozzle are concentrically doubled. It is characterized by having a structure.

According to the present invention, the intake nozzle and the exhaust nozzle have a concentric double structure with the intake nozzle inside. That is, the intake nozzle is arranged in the exhaust nozzle, and the combination with the duct in the third aspect of the invention makes it possible to integrate the intake duct and the exhaust duct.

According to a third aspect of the present invention, there is provided a duct for transferring gas from the exhaust target nozzle to the intake nozzle from the device to be purified to the intake nozzle. It is characterized in that both are formed as a double integrated structure with the outer tube used for exhaust.

According to the present invention, a gas transfer duct between the inside of the device and the filter unit is provided. The inner tube is used for suctioning gas from the device to the filter unit, and the gas is returned from the filter unit to the device. It has a double integrated structure with an outer tube for exhaust. Thereby, bidirectional transfer of gas by one duct is enabled.

According to a fourth aspect of the present invention, an effective sectional area of the exhaust nozzle is made equal to an effective sectional area of the intake nozzle in order to maximize the efficiency of the processing air volume of the intake nozzle and the exhaust nozzle. It is characterized by the following.

According to the present invention, the effective sectional area of the intake nozzle and the effective sectional area of the exhaust nozzle are made equal in the diameter of the intake nozzle and the exhaust nozzle, that is, the sectional area of the intake nozzle and the gap between the exhaust nozzle and the intake nozzle. By making the cross-sectional areas equal to each other, a maximum air volume can be obtained at a constant exhaust nozzle diameter, and the efficiency of purifying gas in the device can be improved.

The invention corresponding to claim 5 is characterized in that the inner pipe and the outer pipe have the same effective sectional area. According to the present invention, the effective sectional area of the inner pipe for intake and the effective sectional area of the outer pipe for exhaust are made equal, that is, the sectional area of the inner pipe is made equal to the sectional area of the gap between the outer pipe and the inner pipe. Thus, the maximum air volume is obtained with a constant duct diameter, and the gas purification efficiency can be improved.

The invention corresponding to claim 6 is characterized in that the end of the intake nozzle is longer than the end of the exhaust nozzle in order to connect the intake nozzle and the exhaust nozzle to the inner pipe and the outer pipe. I do.

According to the present invention, the inner pipe and the outer pipe of the duct are connected to the intake nozzle and the exhaust nozzle, respectively, and the connection work between the intake nozzle and the inner pipe is made longer by making the end of the intake nozzle longer than the end of the exhaust nozzle. Can be easier.

The invention corresponding to claim 7 is characterized in that a gas cooler is provided between the filter and the intake fan in the inner casing. According to the present invention, a gas cooler is provided downstream of the filter in the inner casing, and the suction gas is cooled and returned to the inside of the device, thereby suppressing a temperature rise inside the device caused by gas circulation in a sealed state. Can be.

According to an eighth aspect of the present invention, the inner pipe is held at the center of the outer pipe to maintain a constant airflow, and the relative position between the outer pipe and the inner pipe in the longitudinal direction of the duct is adjusted. It is characterized in that it is provided with a spacer that makes it possible.

According to the present invention, a ring having an inner diameter slightly larger than the outer diameter of the inner tube for passing the inner tube, and a spacer having a leg for fixing the ring to the center of the outer tube are provided.
By attaching the inner tube to the center of the outer tube at an appropriate interval and allowing the inner tube to move in the longitudinal direction while maintaining the inner tube at the center of the outer tube, the amount of circulating air is kept constant, Can adjust the relative position of the ends.

Further, the duct is provided with connecting members for independently extending the inner pipe and the outer pipe,
The total length of the duct can be extended or shortened. Furthermore, since the gas suction position and the discharge position inside the device can be selected arbitrarily, the gas inside the device can be made uniform and the purification efficiency can be increased.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a radioactive gas purifier according to the present invention will be described with reference to FIG. As shown in FIG. 1, the radioactive gas purifying apparatus according to the present embodiment has an inner casing 1 having one end closed and the other end open.
And an outer casing 2 provided so as to cover the entire inner casing 1. In the inner casing 1, a filter 3, a gas cooler 4, an intake fan 5, and a fan motor 6 are arranged in the order of gas flow.

An intake nozzle 7 is connected to the gas inlet side of the inner casing 1, and an exhaust nozzle 8 is connected to the outlet side of the outer casing 2. The intake nozzle 7 and the exhaust nozzle 8 have a concentric double structure in which the intake nozzle 7 is inside and the exhaust nozzle 8 is outside, that is, the intake nozzle 7 is passed through the exhaust nozzle 8. The aperture ratio between the intake nozzle 7 and the exhaust nozzle 8 is a ratio that makes the sectional area of the intake nozzle 7 equal to the sectional area of the gap between the exhaust nozzle 8 and the intake nozzle 7.

Next, the operation of this embodiment will be described. The gas containing radioactive substances is sucked into the inner casing 1 from the intake nozzle 7 by the intake fan 5 rotated by the fan motor 6, and the filter 3, the gas cooler 4,
After passing through the intake fan 5 and the fan motor 6, it is discharged from the inner casing 1 into the outer casing 2.

In this process, radioactive substances and the like in the suction gas are removed by the filter 3, and the purified gas discharged from the inner casing 1 into the outer casing 2 is exhausted from an exhaust nozzle 8 corresponding to an outlet of the outer casing 2. However, since the intake nozzle 7 and the exhaust nozzle 8 have a double structure, actual exhaust is performed from the gap between the intake nozzle 7 and the exhaust nozzle 8. Therefore, the intake nozzle 7 and the exhaust nozzle 8 of the filter unit can be regarded as one nozzle.

Next, a second embodiment of the radioactive gas purifying apparatus according to the present invention will be described with reference to FIGS. 2 (a) and 2 (b). FIGS. 2A and 2B show an intake / exhaust duct according to a second embodiment of the present invention. FIG. 2B shows FIG.
It is an AA sectional view of (a).

In this embodiment, the intake nozzle 7 shown in FIG.
And an exhaust duct connecting the exhaust nozzle 8 to the target device,
An inner tube 9 for transferring the gas into the inner casing 1 and an outer tube 10 for returning the purified gas to the inside of the apparatus.
A double integrated structure 10 covers the inner tube 9.

Next, the operation of the intake / exhaust duct according to the present embodiment will be described. One end of the intake / exhaust duct is placed inside the apparatus with both the inner pipe 9 and the outer pipe 10, and the other end is connected to the filter unit. Here, the inner pipe 9 is connected to the intake nozzle 7,
The outer pipe 10 is connected to the exhaust nozzle 8.

By the operation of the intake fan 5, gas in the device is supplied to the inside of the device through the inner tube 9 of the intake / exhaust duct.
From the inner casing 1.

The gas purified by the filter 3 enters the outer casing 2 from the inner casing 1 and is exhausted from the exhaust nozzle 8 of the outer casing 2 between the inner pipe 9 and the outer pipe 10 of the intake / exhaust duct. And between the outer tube 10 and inside the device. This facilitates the transfer of gas from the device to be purified into the inner cylinder 1.

Next, a third embodiment of the radioactive gas purifying apparatus according to the present invention will be described with reference to FIGS. That is, although the intake nozzle 7 and the exhaust nozzle 8 shown in FIG. 1 have the concentric double structure as described above, the diameter of the intake nozzle 7 with respect to the exhaust nozzle 8 depends on the sectional area of the intake nozzle 7 and the exhaust nozzle 8 and the intake nozzle. The gap 7 has a thickness such that the cross-sectional areas are equal. On the other hand, the inner pipe 9 and the outer pipe of the intake and exhaust duct of FIG.
10 also has a double structure, and the diameter of the inner pipe 9 with respect to the outer pipe 10 is set to a thickness such that the cross-sectional area of the inner pipe 9 is equal to the cross-sectional area of the gap between the outer pipe 10 and the inner pipe 9.

Next, the operation will be described. The efficiency of purifying the gas inside the device is higher as the air volume is larger, provided that the collection efficiency of the filter 3 is the same. Assuming that the conditions of the intake fans 5 and the fan motor 6 are constant, the air volume is determined by the smaller one of the sectional area of the intake nozzle 7 and the sectional area of the gap between the exhaust nozzle 8 and the intake nozzle 7. When the two have the same cross-sectional area, the air volume becomes maximum. On the other hand, the same applies to the relationship between the inner pipe 9 and the outer pipe 10 of the intake / exhaust duct. When the cross-sectional area of the inner pipe 9 is equal to the cross-sectional area of the gap between the outer pipe 10 and the inner pipe 9, the air volume becomes maximum.

Next, a fourth embodiment of the radioactive gas purifying apparatus according to the present invention will be described with reference to FIG. In the present embodiment, the end of the intake nozzle 7 is longer than the end of the exhaust nozzle 8 in order to connect the intake nozzle 7 and the exhaust nozzle 8 to the inner pipe 9 and the outer pipe 10.

Next, the operation will be described. At the time of circulation purification, the inner casing 1 and the outer casing 1 are connected to the intake / exhaust duct by first connecting the intake nozzle 7 to the inner pipe 9, and then connecting the exhaust nozzle 8 to the outer pipe 10. At this time, if the end of the intake nozzle 7 is the same as the end of the exhaust nozzle 8 or shorter than the end of the exhaust nozzle 8, the exhaust nozzle 8 interferes when the intake nozzle 7 and the inner pipe 9 are connected, and it is difficult to work. Therefore, by making the end of the intake nozzle 7 longer than the end of the exhaust nozzle 8, the connection work between the intake nozzle 7 and the inner pipe 9 can be facilitated.

Next, a fifth embodiment of the radioactive gas purifying apparatus according to the present invention will be described with reference to FIG. In the present embodiment, a gas cooler 4 is provided between the filter 3 and the intake fan 5 in the inner casing 1, and thereby cools the gas passing through the filter 3.

Next, the operation of the gas cooler 4 will be described. Since the inside of the device, the inner casing 1 and the outer casing 2 form a closed loop, the gas inside the device is sucked by the intake fan 5, purified by the filter 3 and returned to the inside of the device again. The internal temperature rises. The gas cooler 4 cools the gas purified by the filter 3 and then returns the gas to the device, thereby suppressing a rise in temperature inside the device.

Next, a sixth embodiment of the radioactive gas purifying apparatus according to the present invention will be described with reference to FIG. In this embodiment, a spacer is provided that holds the inner pipe 9 at the center of the outer pipe 10 to maintain a constant air volume and that can adjust the relative position between the outer pipe 10 and the inner pipe 9 in the longitudinal direction of the duct. It is in.

The spacer allows the inner tube 9 to move in the longitudinal direction of the duct while holding the inner tube 9 at the center of the outer tube 10, and is attached to the inside of the outer tube 10 at an appropriate interval. The structure includes a holding ring 11 having an inner diameter slightly larger than the outer diameter of the inner tube 9 for passing the inner tube 9, and three radially extending holding members for fixing the holding ring 11 to the center of the outer tube 10. It consists of 12 legs.

Next, the operation of the spacer will be described. Since the intake / exhaust duct has a double structure of the inner pipe 9 and the outer pipe 10, the tip of the holding leg 12 of the holding ring 11 is attached to the inside of the outer pipe 10. , The holding ring 11 is positioned at the center of the outer tube 10 and the inner tube 9 is passed through the holding ring 11 so that the inner tube 9 is
It can be held at the center of 10 and the air volume of the intake and exhaust ducts can be kept constant. Further, since the inner diameter of the retaining ring 11 is slightly larger than the outer diameter of the inner pipe 9, the inner pipe 9 can move in the longitudinal direction of the intake / exhaust duct, and the length of the inner pipe 9 with respect to the outer pipe 10 can be adjusted. .

Next, a radioactive gas purifying apparatus according to a seventh embodiment of the present invention will be described with reference to FIG. In the present embodiment, as shown in FIG. 4, the inner tube 9 and the outer tube 10 can be independently extended or shortened. That is, a connector 13 for independently extending the inner pipe 9 or the outer pipe 10 is provided at the end of the inner pipe 9 and the outer pipe 10 of the intake / exhaust duct. FIG. 4 shows an extended connection state of the inner pipe 9 and the outer pipe 10 using a plug-in type connecting tool 13 as an example.

The connecting member 13 is connected to one of the inner pipe 9a and the outer pipe 10a.
A large-diameter portion 14 is provided at the end and a pin hole 15 is provided at the large-diameter portion 14. A pin hole 16 is provided at the end of the other inner tube 9b or outer tube 10b. The other inner tube 9 is attached to the large diameter portion 14
b or the outer tube 10b is inserted and the pin 17 is inserted into the pin holes 15 and 16 and fixed.

The function of the extension of the intake / exhaust duct will be described. By allowing the inner pipe 9 or the outer pipe 10 to be extended or shortened, the entire length of the intake / exhaust duct can be extended or shortened, and the optimal length of the intake and exhaust ducts can be adjusted according to the distance to the filter unit. Can be an exhaust duct.

Further, since only the inner tube 9 can be extended, the suction position by the inner tube 9 and the outer tube
The exhaust position by the exhaust pipe 10 can be arbitrarily selected, the re-suction of the exhaust gas from the outer pipe 10 by the inner pipe 9 can be avoided, and the retention of gas inside the apparatus can be prevented, so that the purification efficiency can be improved.

[0045]

According to the present invention, in a radioactive gas purifying apparatus for circulating and purifying gas in a device, even if the target device has only one opening, the gas in the device can be easily purified. It can be carried out. Further, purification efficiency can be improved by preventing gas from staying inside the device, and work efficiency can be improved because only one gas transfer duct is sufficient.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view for explaining a first embodiment of a radioactive gas purifying apparatus according to the present invention.

FIG. 2A is a longitudinal sectional view showing an intake / exhaust duct according to a second embodiment of the present invention, and FIG. 2B is a sectional view taken along line AA of FIG.

FIG. 3 is a longitudinal sectional view showing a sixth embodiment of the radioactive gas purifying apparatus according to the present invention.

FIG. 4 is a longitudinal sectional view showing a connection state of an intake / exhaust duct in a radioactive gas purifying apparatus according to a seventh embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner casing, 2 ... Outer casing, 3 ... Filter, 4 ... Gas cooler, 5 ... Intake fan, 6 ... Fan motor, 7 ... Intake nozzle, 8 ... Exhaust nozzle, 9 ... Inner pipe, 10 ...
Outer tube, 11 ... retaining ring, 12 ... retaining leg, 13 ... connecting tool.

Claims (8)

[Claims] An internal casing having a filter for removing radioactive substances and the like in a gas, an intake fan for sucking a gas to be purified, and a fan motor for driving the intake fan, and having an intake nozzle for taking in the gas to be purified. And an outer casing having an exhaust nozzle that covers the inner casing, receives the purified gas discharged from the inner casing, and guides the gas to the outside. 2. The intake nozzle of the inner casing and the exhaust nozzle of the outer casing are integrated so that the intake nozzle is on the inside and the intake nozzle and the exhaust nozzle have a concentric double structure. Claim 1
The radioactive gas purifying apparatus according to the above. 3. The apparatus according to claim 1, wherein the inside of the device to be purified is supplied to the intake nozzle.
A duct for transferring gas from the exhaust nozzle to the device to be purified is provided, and the duct has an inner tube for intake and an outer tube for exhaust, and has a double integrated structure. Item 3. A radioactive gas purifying apparatus according to Item 2. 4. An effective sectional area of the exhaust nozzle is made equal to an effective sectional area of the intake nozzle in order to maximize the efficiency of the processing air volume of the intake nozzle and the exhaust nozzle. 3. The radioactive gas purifying apparatus according to 2. 5. The radioactive gas purifying apparatus according to claim 3, wherein the inner pipe and the outer pipe have the same effective sectional area. 6. The exhaust nozzle end is longer than the exhaust nozzle end for connecting the intake nozzle and the exhaust nozzle to the inner pipe and the outer pipe. Radioactive gas purifier. 7. The radioactive gas purifying apparatus according to claim 1, wherein a gas cooler is provided between the filter and the intake fan in the inner casing. 8. A spacer is provided which holds the inner tube at the center of the outer tube to maintain a constant air volume and adjusts a relative position between the outer tube and the inner tube in a longitudinal direction of the duct. The radioactive gas purification apparatus according to claim 3, wherein