JPH02191517A - Leakage detecting device for high efficiency filter - Google Patents

Abstract

PURPOSE:To efficiently identity the leakage spot of filter by throwing test fine particles into the front side of a high efficiency filter and scanning the back side of the filter to project light to the leaked particles and collecting the light reflected by the test fine particles. CONSTITUTION:The test fine particles B are thrown into the front side of the high efficiency filter 2 through a throwing-in nozzle 6. Two light sources 3a, 3b scan the back surface of the filter 2 to project the light to the test fine particles B leaking from the filter 2. A converging lens 4 and a photomultiplier 4' collect the light 3c reflected by the fine particles B. As a result, the work efficiency is improved and the health of workers in secured in safety. When the equipment to be tested with the leakage test is in an nuclear power plant, or in nuclear fuel treatment facilities, the radioactive ray receiving quantity of a worker is reduced. Moreover, the leakage test of high efficiency filter is swiftly carried out without shortening the life of the sound high efficiency filter.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to leakage inspection of high-efficiency filters in air purification devices applied to nuclear power plants, nuclear fuel processing facilities, semiconductor manufacturing plants, biotechnology facilities, etc. It is related to the device.

(Prior Art) Air purification devices that purify the air by removing particulates from the air using high-efficiency filters are used in various facilities. The conventional example is explained with reference to Figs. 6 and 7. (1)
is the main body of the air purifying device, (8) is the filter mounting frame fixed by welding in the air purifying device (1), and (2) is the filter holding bracket (2) attached to the filter mounting frame (8).
9) and a packing (10), this part is called a filter bank. This filter bank is designed and manufactured to prevent bypass leakage from any part other than the ventilation part of the high-efficiency filter (2), and allows the airflow (A) containing particulates to be efficiently routed from the inlet of the air purification device body (1). The airflow (A) is guided to the front side of the filter (2), and particulates are captured and removed by the high efficiency filter (2).
The air is discharged to the outside of the air purifier main body (1) through the outlet of the air purifier main body (1) on the rear side of the air purifier main body (1).

In the conventional air purification device shown in FIGS. 6 and 7, (1) the high efficiency filter (2) is not transported during transportation until it is attached to the filter mounting frame (8) in the air purification device main body (1), and during the service period. Damage to the filter (■) or high efficiency filter (2) and filter mounting frame (8) when installing the filter
Due to poor adhesion, etc.

Bypass leaks may occur, reducing the particulate removal function of the air purification device. Therefore, before using the air purification device, it is necessary to inspect the health of the high efficiency filter (2) and the parts around it. In this leakage test, test particles are guided into the air purification device from the inlet of the air purification device along with the airflow (A), and the ratio of the airborne particle concentration (or the number of airborne particles) between the upstream side of the filter bank and the downstream side of the filter bank is carried out. The health of the high-efficiency filter (2) and its surrounding parts is evaluated by measuring and calculating the ratio of

If the particulate removal function is poor, the part where the test particulates are leaking is searched for and repaired, or some of the high-efficiency filters (2) are replaced with healthy ones.

A conventional example of the above leakage testing device is shown in Fig. 8.9. (6
) is the test particle injection nozzle installed at the entrance of the air purification device main body (1), (11) is the light scattering photometer and test particle suction device, and (12) is the high efficiency filter (
2) is a sampling nozzle that moves on the back side of the device to scan for leakage of test particles (B); When the test particles (B) are introduced into the air purifier main body (1) through the inlet of the air purifier main body (1) - the high-efficiency filter (2) and the air purifier main body outlet to the outside of the air purifier main body, (6) into the upstream side (front side) of the high-efficiency filter (2) on the airflow (A), and if there is a leakage point (2a) in a part of the high-efficiency filter (2),
The test particles (B) are placed on the downstream side of the high efficiency filter (2) (
leaks to the rear side). At this time, 9 workers moved the sampling nozzle (12) connected to the light scattering photometer and the test particle suction device (11) to the back side of the high efficiency filter (2), etc. If there is a leak in part (2a) of the high-efficiency filter (2), the test particles (B) leaked from there are scanned to see if there is any leakage of test particles (B). (12) to collect by suction.

Light scattering photometer and test particle suction device (11
) to detect the airborne particulate concentration, display the results on the photometer indicator (13), read changes in the airborne particulate concentration, pinpoint the leak location, and repair the area. , some of the high-efficiency filters (2) are replaced with healthy ones.

(Problems to be Solved by the Invention) In the conventional high-efficiency filter leakage testing apparatus shown in FIG. (
12) to the back side of the high efficiency filter (2),
It is necessary to scan the high efficiency filter (2) etc. to see if there is any leakage of test particles (B).
) It takes a lot of time to perform the leakage test, which results in poor work efficiency and one worker inhaling the test particles (B), which is harmful to his health. ■For air purification equipment at nuclear power plants and nuclear fuel facilities.

The leakage test takes a long time, during which one worker is exposed to radiation, increasing the amount of radiation exposure.

(2) The test particles will be collected by the healthy high-efficiency filter (2) during the long leak test time, which will shorten the life of the healthy high-efficiency filter (2).

Further, when the air purifying device main body (1) is small, it is difficult for one worker to enter the air purifying device main body (1), and there is a problem that it is impossible to perform leakage test work on the high efficiency filter (2), etc.

The present invention has been proposed in view of the above-mentioned problems, and its purpose is to improve work efficiency without impairing the health of workers. Radiation exposure can be reduced. Does not impair the life of a healthy high-efficiency filter. Furthermore, even if the air purification device itself is small.

The object of the present invention is to provide a leak testing device for a highly efficient filter that can perform leak testing work.

(Means for Solving the Problems) In order to achieve the above objects, the high-efficiency filter leakage testing device of the present invention has an injection nozzle that injects test particles toward the front side of the high-efficiency filter, and a Two light sources that scan the back side of the high-efficiency filter and illuminate the test particles leaking from the high-efficiency filter, and a condenser lens and photomultiplier tube that collect the reflected light from the test particles. It is equipped with

(Function) The high-efficiency filter leakage inspection device of the present invention is configured as described above, and before the test in which test particles are introduced from the injection nozzle, the irradiated light from one light source is applied to the filter bank of the high-efficiency filter. The downstream side is irradiated parallel to the same high-efficiency filter, the entire downstream side of the filter bank is scanned, the response (background level) of the photomultiplier tube at that time is examined, and a background curve is drawn. Next, the irradiation light from the other light source is irradiated onto the downstream side of the filter bank of the high-efficiency filter in parallel to the same high-efficiency filter, and the entire downstream side of the filter bank is scanned, and the response of the photomultiplier tube at that time (back (ground level).

Draw the background curve. Next, the test particles are introduced into the inlet of the air purifier main body from the injection nozzle, carried by the airflow, and guided to the upstream side (front side) of the high-efficiency filter. During this leakage test, the irradiated light from one light source is irradiated parallel to the filter bank downstream of the high-efficiency filter, and the entire downstream side of the filter bank is scanned, and the photomultiplier tube at that time is Examine the response (background level) and draw the background curve.

Next, the irradiation light from the other light source is irradiated onto the downstream side of the filter bank of the high-efficiency filter in parallel to the same high-efficiency filter.
Scan the entire downstream side of the same filter bank, examine the response (background level) of the photomultiplier tube at that time, draw a background curve, and use the graph obtained from the above scanning to determine the reflected light, that is, the leakage. Read the reflected light (scattered light) from each light source that hits the test particles, and calculate the distance from the other light source to the test particles leaking from the other light source using the scanning angle and the distance between each light source. The horizontal distance and the vertical distance from the light source to the leaked test particles are calculated to identify the leak point of the high efficiency filter.

(Example) Next, the high-efficiency filter leakage inspection device of the present invention will be explained with reference to an example shown in FIGS. (1) A filter mounting frame fixed by welding inside the frame, (2) a high-efficiency filter detachably mounted to the same filter mounting frame (8) via a filter holding fitting and packing;
(2a) is the leakage point of the same high efficiency filter (2), (
3a) (3b) are two light source bodies arranged downstream (back side) of the filter bank of the same high efficiency filter (2), (3
aυ (3bl) irradiates the irradiated light from the same light source (3a) (3b) to the downstream side of the filter bank of the high efficiency filter (2) in parallel to the high efficiency filter (2), and illuminates the entire downstream area of the filter bank. irradiation light), (θa) is the scanning angle of the light source (3a), (θb) is the scanning angle of the light source (3b), and (3c) is the reflection reflected from the leaked test particle CB). Light (scattered light), (4) is a condenser lens that collects the reflected light (3c), and (4”) is a photomultiplier tube.

(5) is the indicator connected to the same photomultiplier tube (4”), (
6) is the test particulate injection nozzle installed at the entrance of the air purification device main body (1), and (7) is the high efficiency filter (2).
) The main body of the air purifying device (1) on the downstream side of the fluita bank (1) is the light heat reflecting plate installed on the outer peripheral wall, (2) is the light source body (3a) (3)
b), (X) is the horizontal distance from the light source (3b) to the leaked test particles (B), and (Y) is the distance between the light source (3b)
It is the vertical distance from b) to the leaked test particles (B).

Next, the operation of the high-efficiency filter leakage testing device shown in FIGS. 1 to 5 will be explained in detail. Test fine particles (B
) from the injection nozzle (6). 1 light source (
The irradiation light (3a1) of 3a) is irradiated onto the downstream side of the filter bank of the high-efficiency filter (2) in parallel to the high-efficiency filter (2) to scan the entire downstream side of the filter bank, and the photoelectrons are multiplied at that time. Check the response (background level) of the tube (4'), read it with the indicator (5), and draw a background curve (see the broken line in Figure 4 (I)).

Next, the irradiation light (ab+) from the light source (3b) is irradiated onto the downstream side of the filter bank of the high-efficiency filter (2) in parallel to the high-efficiency filter (2) to scan the entire downstream side of the filter bank. Examine the response (background level) of the photomultiplier tube (4゛) at this time, read it with the indicator (5), and draw the background curve (Fig. 4 (n)
). Next, the test particles (8) are introduced from the injection nozzle (6) into the inlet of the air purification device main body (1), and the test particles (B) are carried by the airflow (A) to the high-efficiency filter (2). Lead to the upstream side (front side). During this leakage test, the irradiated light (3a,) from the light source (3a) is transferred to the downstream side of the filter bank of the high efficiency filter (2).
2), scan the entire downstream side of the same filter bank, check the response (background level) of the photomultiplier tube (4゛) at that time, and read this with the indicator (5). Draw a background curve (see solid line in Figure 4 (1)). Next, the irradiation light (3bl) of the light source (3b)
is irradiated onto the downstream side of the filter bank of the high-efficiency filter (2) in parallel to the same high-efficiency filter (2), the entire downstream side of the filter bank is scanned, and the photomultiplier tube (4゛)
Check the response (background level), read it with the indicator (5), and draw the background curve (
(See solid line in FIG. 4(n)). Reflected light from the graph in Figure 4 obtained by the above scanning.

That is, the scan angle (ea
) (θb) and calculate the same scanning angle (ea) (θb)
and the distance (L) between the light sources (3a) and (3b), (
(see the following formula), the horizontal distance (X) from the light source (3b) to the leaked test particles (B), and the vertical distance (Y) from the light source (3b) to the leaked test particles (B). Calculate and identify the leak point (2a) of the high efficiency filter (2) (Effects of the Invention) The high efficiency filter leak inspection device of the present invention, as described above, detects the leak point (2a) of the high efficiency filter (2) before the test in which the test particles are introduced from the input nozzle. , the irradiation light from one light source is irradiated parallel to the filter bank downstream of the high-efficiency filter, and the entire downstream side of the filter bank is scanned, and the response of the photomultiplier tube at that time (background level) and draw the background curve. Next, the irradiation light from the other light source is irradiated onto the downstream side of the filter bank of the high-efficiency filter in parallel with the high-efficiency filter to scan the entire downstream side of the filter bank,
Response of the photomultiplier tube at that time (background level)
Go around 8 times and draw the curve of the bank ground. Next, test particles are introduced into the main body of the air purification device through the injection nozzle, carried by the airflow, and guided to the upstream side (front side) of the high-efficiency filter. During this leakage test, the irradiated light from one light source is irradiated parallel to the filter bank downstream of the high-efficiency filter, and the entire downstream side of the filter bank is scanned, and the photomultiplier tube at that time is Examine the response (background level) and draw the background curve. Next, the irradiation light from the other light source is irradiated onto the downstream side of the filter bank of the high-efficiency filter in parallel to the same high-efficiency filter.

The entire downstream side of the filter bank was scanned, the response (background level) of the photomultiplier tube at that time was examined, a background curve was drawn, and the reflected light, ie, the reflected light, was drawn from the graph obtained by the above scanning.

Read the reflected light (scattered light) from each light source that is reflected by the leaked test particles.

Using each scanning angle and the distance between each light source, the horizontal distance from the other light source to the leaked test particles and the vertical distance from the same light source to the test particles leaked are calculated to achieve high efficiency. Since the leakage point of the filter is identified, there is no need for one worker to enter the main body of the air purifying device to perform leakage test work, which improves work efficiency and does not harm the health of the workers. Furthermore, if the equipment being tested for leakage is a nuclear power plant or nuclear fuel processing facility, the amount of radiation exposure per worker can be reduced. In addition, the leakage test of the high-efficiency filter can be quickly performed without damaging the life of a healthy high-efficiency filter. Additionally, there is no need for workers to enter the air purification device itself, even if the air purification device itself is small.

This has the effect of allowing leak test work to be carried out.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a leakage testing device for a high-efficiency filter according to the present invention, FIG. 2 is a vertical cross-sectional side view thereof, and FIG. Front view, 4th.
Fig. 5 is an explanatory diagram of its operation, Fig. 6 is a longitudinal side view showing a conventional air purifying device, Fig. 7 is an enlarged longitudinal side view of the arrow ■ in Fig. 6, and Fig. 8 is an illustration of a conventional high-efficiency filter. FIG. 9 is an enlarged vertical side view of the portion indicated by the arrow ■ in FIG. 8. (2)...High efficiency filter, (3a) (3b)
...Light source, (3a+) (3b+) ” '
Irradiation light, (3c)...Reflected light. (4)...Condensing lens, (4')...Photomultiplier tube. (6)...Input nozzle, (A)...Airflow, (B)...
...Particles for testing.

Claims (1)

[Claims] An injection nozzle that injects test particles toward the front side of the high-efficiency filter, and two light sources that scan the back side of the high-efficiency filter and shine light on the test particles leaked from the high-efficiency filter. A leak testing device for a high-efficiency filter, characterized by comprising a condenser lens and a photomultiplier tube that collect reflected light reflected from the test particles.