JPH04197412A - Dust radioactivity monitor apparatus and method for washing filter paper - Google Patents

Abstract

PURPOSE:To reduce the amount of the waste in a radioactive rays control area, in a dust radioactivity monitor apparatus measuring the radioactive concn. of the dust in the radioactive rays control area, by providing a washing means allowing air to flow to the filter paper after the measurement of radioactivity in the direction opposite to that at the time of dust collection. CONSTITUTION:Filter paper is delivered to a position 2b from a filter paper holder 1 and the air of a place 9 where radioactive concn. must be measured is sucked by a pump 3 to collect dust on the surface of the filter paper. Next, the filter paper is transferred to a position 2c and, after the radioactivity in the dust is detected by a radioactivity detector 4, the filter paper is transferred to a position 2d. At this position 2d, air is sprayed to the filter paper in the direction opposite to the direction at the time of the collection of dust at the position 2b to wash the filter paper. Since the exhaust air of the pump 3 used in dust collection is used as the air for blowing off the dust, dust is already perfectly removed when the air sucked by the pump 3 passes through the filter paper at the position 2b and the filter paper is not contaminated by exhaust air. The dust at the position 2d is discharged to the outside 10 along with air and the filter paper after washing is set to the uppermost stage 2e of the filter paper holder 1.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a dust radiation monitoring device for measuring radioactivity concentration by collecting dust in the air in a radiation controlled area on a filter paper, etc. This invention relates to a filter paper cleaning method.

[Conventional technology]

In the conventional dust radiation monitor device,
As described in Publication No. 879, filter papers are taken out one by one from a filter paper holder in which a plurality of filter papers are set, dust containing radioactivity in the air is collected on the filter paper, and further radiation detection is performed. Radiation measurements are carried out using a device, and all filter paper is discarded after the measurement is completed.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the disadvantage that the amount of waste increases because the filter paper after radiation measurement is discarded after being used only once. Moreover, since the filter paper after radiation measurement contains radioactivity, it must be stored in a limited and specific area, and there is a strong desire to somehow suppress the increase in filter paper waste.

Furthermore, when the filter paper in the filter paper holder runs out, maintenance personnel must replace it with a new filter paper, but since this work is performed within a radiation controlled area, there is a problem in that the burden on the maintenance personnel is heavy.

The purpose of the present invention is to enable filter paper to be used multiple times,
It is an object of the present invention to provide a dust radiation monitoring device that reduces radioactive waste and reduces filter paper replacement work, and a filter paper cleaning method for the device.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a filter paper holder holding a plurality of filter papers, and a filter paper holder that allows air in a place where radioactivity concentration is to be measured to be blown out from the filter paper holder. A dust radiation monitor comprising a suction means for suctioning through a filter paper, a radiation measurement means for measuring the radiation of dust sucked by the suction means and collected on the filter paper, and a display means for displaying the measurement result. The apparatus is equipped with a cleaning means for cleaning the filter paper after radiation measurement in order to reuse the filter paper.

The present invention also provides a filter paper holder holding a plurality of filter papers, a suction means for sucking air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder,
In a dust radiation monitoring device comprising a radiation measuring means for measuring radiation of dust sucked by the suction means and collected on the filter paper, and a display means for displaying the measurement result, the filter paper after radiation measurement is provided. A cleaning means is provided for cleaning the filter paper by flowing air in the opposite direction to that used during dust collection.

The present invention also provides a filter paper holder holding a plurality of filter papers, a suction means for sucking air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder,
A dust radiation monitoring device comprising a radiation measuring means for measuring the radiation of the dust sucked by the suction means and collected on the filter paper, and a display means for displaying the measurement result. Means for storing filter paper whose radiation level is found to be above a predetermined value from the measurement results in a separate holder, and washing the filter paper by flowing air in the opposite direction to that during dust collection through the filter paper whose radiation level is less than the predetermined value. A cleaning means is provided.

The present invention also provides a filter paper holder holding a plurality of filter papers, a suction means for sucking air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder,
In a dust radiation monitoring device comprising a radiation measuring means for measuring radiation of dust sucked by the suction means and collected on the filter paper, and a display means for displaying the measurement result, the filter paper after radiation measurement is provided. A cleaning device that cleans the filter paper by flowing air in the opposite direction to that used during dust collection, an air pressure measuring device that measures the air pressure on the upstream or downstream side of the filter paper when cleaning the filter paper, and the measurement results can be used to prevent clogging of the filter paper. When it is determined, a means for storing the filter paper in a separate holder is provided.

The present invention also provides a filter paper holder holding a plurality of filter papers, a pump that sucks air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and a filter paper holder that holds a plurality of filter papers. In a dust radiation monitoring device equipped with a radiation measuring means for measuring the radiation of dust collected on a filter paper and a display means for displaying the measurement result, the exhaust air of the pump is used to detect the radiation after the radiation measurement. A cleaning means is provided for cleaning the filter paper by flowing air in the opposite direction to that used during dust collection.

The present invention also provides a filter paper holder holding a plurality of filter papers, a pump that sucks air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and a filter paper holder that holds a plurality of filter papers. In a dust radiation monitoring device equipped with a radiation measuring means for measuring the radiation of dust collected on a filter paper and a display means for displaying the measurement result, the exhaust air of the pump is used to detect the radiation after the radiation measurement. The filter paper is provided with a cleaning means for cleaning the filter paper by flowing air in a direction opposite to that during dust collection, and a conveyance means for conveying the filter paper after cleaning and returning it to the filter paper holder.

The present invention also provides a filter paper holder holding a plurality of filter papers, a pump that sucks air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and a filter paper holder that holds a plurality of filter papers. A dust radiation monitoring device comprising a radiation measuring means for measuring radiation of dust collected on a filter paper and a display means for displaying the measurement result, a nozzle for blowing the exhaust air of the pump downward;
Rotating and tilting the filter paper after the radiation measurement,
and a drive unit that causes the back side of the dust collection surface of the filter paper to face the nozzle.

Furthermore, the filter paper cleaning method of the present invention is to wash the filter paper after radiation measurement by blowing exhaust air from a pump that collects dust on the filter paper to the back side of the dust collection surface of the filter paper after radiation measurement.

[Effect]

According to the above configuration, by washing the filter paper after radiation measurement with the washing means, the dust collected on the filter paper can be removed, and the filter paper can be set in the filter paper holder and reused. becomes possible.

Specifically, by flowing air through the filter paper after radiation measurement in the opposite direction to that during dust collection, the dust collected on the filter paper can be easily removed. In this case, if a pump is used to collect dust on the filter paper, the exhaust air from the pump can be blown onto the back side of the dust collection surface of the filter paper, and the blown exhaust air can be used to remove the dust on the filter paper. It becomes possible to remove it. Note that when blowing the exhaust air from the pump onto the filter paper, if the exhaust air is directed downward, dust adhering to the filter paper can be easily peeled off, thereby increasing cleaning efficiency.

Further, filter paper whose radiation level is found to be higher than a predetermined value as measured by the radiation measuring means is stored in a separate holder without being washed.

Furthermore, if the air pressure on the upstream side or downstream side of the filter paper is measured by the air pressure measuring means while the filter paper is being washed by the washing means, the state of clogging of the filter paper can be known. In other words, when the filter paper is clogged, the air pressure on the upstream side of the filter paper decreases and the air pressure on the downstream side of the filter paper increases, so if you measure the air pressure on either the upstream or downstream side of the filter paper, Can detect clogging conditions. and,
If the clogging is large, store it in a separate holder.

Further, if a means for transporting the filter paper after washing and returning it to the filter paper holder is provided, it becomes possible to automate all of the dust collection on the filter paper, radiation measurement, washing of the filter paper, and setting on the filter paper holder.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a dust radiation monitoring device of the present invention. As shown in the figure, the filter paper holder 1, which holds filter papers stacked in multiple stages, sends out the filter paper located at the lowest stage 2a in response to a contact signal from an external timer 12, and the delivered filter paper is transferred to the bottom stage 2b. Move to position. 2 filter papers
When the pump 3 is driven at the position b, the air in the location 9 where the radioactive concentration is to be measured is sucked through the suction pipe 7. As the sucked air passes through the filter paper at position 2b, the dust present at location 9 is collected on the surface of the filter paper. Here, the air suction is x [A/min]
, the suction time is Tl [min], then the dust collected on the filter paper is that which existed in the air in x-TI [Q].

Next, the filter paper at position 2b is transferred to position 2C by a contact signal from the timer 12, and radiation in the dust is detected at this position by the radiation detector 4. Then, the detection signal is sent to the module 5, and the radiation concentration of the air in x-71 [Q] is displayed. At the same time, module 5
From there, a level signal 6a for the recorder and an alarm signal 6b when the radioactivity concentration exceeds a certain level are outputted to the outside.

Next, the filter paper at position 2C is transferred to position 2d by a contact signal from timer 12. Then, at the position 2d, air is blown onto the filter paper in the opposite direction to that during dust collection at the position 2b, and the dust adhering to the filter paper is blown off, thereby cleaning the filter paper. In this case, the air for blowing off dust is the exhaust air of the pump 3 used for dust collection. In other words, since the dust has been completely removed from the air sucked into the pump 3 when it passes through the filter paper at position 2b, even if the exhaust air from the pump 3 is blown onto the filter paper again, this exhaust air will cause the filter paper to It can be used for cleaning without contaminating the water. And 2
The air blown onto the filter paper at the position d is discharged to the outside 1o through the discharge pipe 8 together with the blown dust.

The filter paper that has been washed is transported by a transport device 11 driven by a contact signal from a timer 12, and is set at 2e on the top stage of the filter paper holder l for reuse.

In this embodiment, the same pump 3 is used for dust collection and cleaning, but separate pumps may be used for dust collection and cleaning.

Next, the operation of the filter paper will be explained using the flowchart shown in FIG. It is assumed that filter papers A, B, C, D, and E are stacked in the order of ABCDE in the filter paper holder 1 from the position of the lowest stage 2a. In addition, external contact signals from the timer 12 are all output simultaneously every T1+72 hours to the lowest stage 2a, dust collection position 2b, radiation measurement position 2c, and cleaning position 2d of the filter paper holder 1, and each filter paper moves to the next position. Since it takes 12 hours to move to the center, dust collection, radiation measurement, and cleaning will take T1 hours. Filter paper A operates in the order of dust collection, radiation measurement, cleaning, and setting in the filter paper holder.

Also, when filter paper A is sent out from filter paper holder 1, filter paper B
moves to position 2a and operates in the same way as filter paper A. The same applies to filter papers C, D, and E.

Further, using the alarm signal 6b from the module 5, filter paper that has become contaminated beyond a certain level is stored in a separate holder without being reused.

Furthermore, when cleaning the filter paper at position 2d, measure the pressure of the air being blown, and if the pressure does not fall below a certain value after T1/2 hours, the filter paper will become clogged and cannot be reused. Filter paper is also stored in a separate holder.

Moreover, when moving the filter paper from the position 2C to the position 2d, the filter paper can be turned over and the exhaust air from the pump 3 can be blown from above, thereby further increasing the filter paper cleaning effect. In this case, when setting the filter paper washed at position 2d on the uppermost stage 2e of the filter paper holder 1, it is necessary to turn the filter paper over again.

Note that at the position 2d, the filter paper may be held vertically and air may be blown from the side.

Next, details of the filter paper transport mechanism will be explained using FIGS. 3 to 5. As shown in the figure, a moving table 13 is provided below the filter paper holder 1.
There are four holes on the top for inserting filter paper.

The moving table 13 is connected to a motor 15 via a gear 14, and rotates in the direction of an arrow 19 as the motor 15 rotates. Further, a rotating body 16 is arranged above the filter paper holder 1,
This rotating body 16 also has one hole newly formed into which a filter paper is inserted. The rotating body 16 is connected to a motor 17, and rotates in the direction of arrow 20 or 21 as the motor 17 rotates.

Radiation detectors 4 are disposed at positions 2b and 2c on the movable table 13, and dust collection and radiation measurement can be performed at these positions. Further, a discharge pipe 8 is disposed at a position 2d on the movable table 13, and the filter paper can be washed at this position. Furthermore, a sloped body 22 is provided below the position 2j on the movable table 13, and the tip of this sloped body 22 reaches below the position 2g on the rotating body 16.

And, between the rotating body 16 and the tip of the slope body 22,
A crane 18 is provided, which includes a belt having an arm for receiving the filter paper and a booby for driving the belt.

According to the filter paper transport mechanism configured as described above, when the moving table 13 rotates 90 degrees in the direction of the arrow 19,
The filter paper located at the lowest stage 2a of the filter paper holder 1 is 2b,
It is transported to position 2c.

At positions 2b and 2c, after dust collection is performed, the radiation concentration in the dust is measured by the radiation detector 4. When the radiation density measurement is completed, the moving table 13 is further rotated 90 degrees in the direction of the arrow 19, and the filter paper is conveyed to the position 2d, where the filter paper is washed. When the filter paper washing is completed, the movable table 13 is further rotated 90 degrees in the direction of the arrow 19, and the filter paper is conveyed to position 2j, at which point the filter paper falls due to its own weight. Then, the filter paper falls onto the slope body 22, further slides down on the slope body 22, and reaches the position 2f. When the filter paper reaches the 2f position, the crane 18 is driven to lift the filter paper from the 2f position to the 2g position and insert the filter paper into the hole in the rotating body 16. Next, the rotating body 16 rotates 180 degrees in the direction of the arrow 20 to remove the filter paper for 2 hours.
and set it in the filter paper holder 1. At this time, when the filter paper is to be discarded, the rotating body 16 rotates 90 degrees in the direction of arrow 21, and at the position 21, the filter paper to be discarded is stored in another holder (not shown).

In the above embodiment, dust collection and radiation measurement are performed in 2b and 2c.
Although this was done at the same location, it can also be done at a different location. In this case, the moving table 13 has five holes formed at equal intervals and rotates by 72 degrees.

〔Effect of the invention〕

As explained above, according to the present invention, the filter paper can be reused, so it is possible to reduce the amount of waste in the radiation controlled area.

Furthermore, since filter paper with high radioactivity concentration or clogged filter paper is not reused, it is possible to reliably prevent the spread of radioactive contamination.

Furthermore, by providing a transport device to transport the filter paper after cleaning to the filter paper holder, all operations such as dust collection, radiation measurement, cleaning, and setting in the filter paper holder can be automated, reducing the burden on maintenance personnel. be able to.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the dust radiation monitoring device of the present invention, Fig. 2 is a time chart showing the operation of the filter paper, Figs. 3 to 5 show the filter paper transport mechanism, and Fig. 3 is a schematic top view thereof. 4 is a sectional view taken along line A-All in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG. 3. 1...Filter paper holder, 2a-2j...Filter paper position, 3
... Pump, 4... Radiation detector, 5... Module, 7... Suction piping, 8... Discharge piping, 11
...Transport device, 12...Timer, 13...Moving table, 14...Rotating body, 15, 17...Motor,
18... Crane, 22... Slope body.

Claims (1)

[Claims] 1. A filter paper holder holding a plurality of filter papers, a suction means for sucking air in a place where radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the suction means In a dust radiation monitoring device comprising a radiation measuring means for measuring the radiation of dust sucked and collected on the filter paper, and a display means for displaying the measurement result, after the radiation measurement for reusing the filter paper. What is claimed is: 1. A dust radiation monitoring device comprising a cleaning means for cleaning a filter paper. 2. A filter paper holder holding a plurality of filter papers, a suction means for sucking the air in the place where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the suction means suctioning the air onto the filter paper. In a dust radiation monitoring device equipped with a radiation measuring means for measuring the radiation of dust collected in the dust and a display means for displaying the measurement result, air is applied to the filter paper after radiation measurement in the opposite direction to that during dust collection. What is claimed is: 1. A dust radiation monitoring device comprising a cleaning means for cleaning a filter paper by flushing the filter paper with the filter paper. 3. A filter paper holder holding a plurality of pieces of filter paper, a suction means for sucking the air in a place where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the suction means suctioning the air onto the filter paper. In a dust radiation monitoring device comprising a radiation measuring means for measuring radiation of dust collected in a dust radiation monitor, and a display means for displaying the measurement result, the radiation level is determined to be equal to or higher than a predetermined value based on the measurement result of the radiation measuring means. A means for storing the filter paper found to be in a separate holder;
A dust radiation monitoring device comprising a cleaning means for cleaning the filter paper whose radiation level is less than a predetermined value by flowing air in a direction opposite to that during dust collection. 4. A filter paper holder holding a plurality of filter papers, a suction means for sucking the air in the place where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the suction means suctioning the air onto the filter paper. In a dust radiation monitoring device equipped with a radiation measuring means for measuring the radiation of dust collected in the dust and a display means for displaying the measurement result, air is applied to the filter paper after radiation measurement in the opposite direction to that during dust collection. a cleaning means for washing the filter paper by flushing it with air; an air pressure measuring means for measuring the air pressure on the upstream or downstream side of the filter paper during filter paper washing; A dust radiation monitoring device characterized by comprising: a storage means. 5. A filter paper holder holding a plurality of filter papers, a pump that suctions the air in the area where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the pump sucks the air and collects it on the filter paper. In a dust radiation monitoring device equipped with a radiation measuring means for measuring radiation of dust and a display means for displaying the measurement result, the dust is collected on a filter paper after radiation measurement using the exhaust air of the pump. A dust radiation monitoring device characterized by being provided with a cleaning means for cleaning a filter paper by flowing air in a direction opposite to the time. 6. A filter paper holder holding a plurality of filter papers, a pump that sucks the air in the area where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the air that is sucked by the pump and collected on the filter paper. In a dust radiation monitoring device equipped with a radiation measuring means for measuring radiation of dust and a display means for displaying the measurement result, the dust is collected on a filter paper after radiation measurement using the exhaust air of the pump. A dust radiation monitoring device comprising: a cleaning means for cleaning the filter paper by flowing air in a direction opposite to the time; and a conveyance means for conveying the filter paper after cleaning and returning it to the filter paper holder. 7. A filter paper holder holding a plurality of filter papers, a pump that sucks the air in the area where the radioactivity concentration is to be measured through the filter paper sent out from the filter paper holder, and the air that is sucked by the pump and collected on the filter paper. A dust radiation monitoring device comprising a radiation measuring means for measuring radiation of dust, and a display means for displaying the measurement result, comprising: a nozzle for blowing the exhaust air of the pump downward; a drive unit that rotates and tilts the filter paper so that the back side of the dust collection surface of the filter paper faces the nozzle;
A dust radiation monitoring device characterized by being provided with. 8. A method for cleaning filter paper, which comprises washing the filter paper after radiation measurement by blowing exhaust air from a pump that collects dust on the filter paper onto the back side of the dust collection surface of the filter paper after radiation measurement.