JPS5954936A - Bubble detector - Google Patents

Abstract

PURPOSE:To detect a bubble highly accurately and simply, by forming a horizontal curtain of a laser beam in a transparent liquid, and photoelectrically detecting the scattering of the beam caused by the rising bubble in the liquid. CONSTITUTION:A laser beam generated by an oscillator 1 is reflected by a mirror 2 and projected on a polygonal mirror 3. Since the polygonal mirror 3 is rotated at a high speed, the laser beam is deflected right and left at a certain angle, and a so-called light curtain 4 is visually formed. A liquid tank 5 comprising a transparent container is filled with a transparent liquid. A material to be checked 6 is placed at the bottom part. The inside of the material to be checked 6 is filled with a gas whose pressure is higher than the atmosphere. Therefore, when the material to be checked 6 leaks, a bubble is yielded. A light converging device 7 receives the broad light, which is formed by the polygonal mirror 3 and supplies the light to a photoelectric device 8. In the forward region of the bubble in the direction of the advance of the beam, the bright and dark indications are present in accordance with the rise of the bubble. The changing state is detected by the photoelectric device 8 through the light converging device 7, and the bubble is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a bubble detection device that can be used to perform one-time leak inspection of, for example, fluid containers. Usually, the item to be inspected is submerged in water and the number of bubbles is observed.

However, it is difficult to automate this method, so for example, methods have been developed to automatically detect leaks by detecting the decrease in various components. The reality is that many places are using Mij's underwater testing method, which has poor accuracy. The reason for this is, for example, if a 10'□t container was inspected using the underwater inspection method, one bubble with a diameter of 1 yrn was generated every □second, then a 10 second inspection + would generate 10 bubbles. , especially to hire. The fact that about 5 cubic meters of leakage occurred in 110 seconds clearly indicates that there is a problem. However, even if we try to detect this as a pressure drop, the pressure drop in the same 10 seconds is only 5/10 million, so it is impossible to detect it in this amount of time.

'-17), l:U'/"Yasunaka"'? Leakage test using ``Nebub''! So:,,':'l,l''Although the accuracy is quite satisfactory, it has the disadvantage that it is difficult to automate.
・・'1::1□11 So this invention is 100%! The second objective of this invention is to provide a bubble detection device that maintains a constant U constant and can easily automate leakage inspection. liquid (e.g. water)
A horizontal curtain of laser beam is formed inside the liquid, and changes caused by the scattering of the laser beam by gas and oil floating in the liquid toward this curtain are detected photoelectrically and the bubbles are swallowed. Currently,
It can be configured to detect the thick expression or number '□.
'1 The present invention will now be further clarified with reference to the accompanying drawings.

FIG. 1 schematically shows an embodiment of the device according to the invention, in which a laser beam is generated from a laser oscillator, is reflected by a mirror beam, and is irradiated onto a polygonal mirror 3. Ru. This polygonal mirror 3 can be rotated at high speed, so that the laser beam from the polygonal mirror 3 is swung at a certain angle to the left and right, visually forming a so-called front curtain q.

sr:r, in a liquid tank consisting of a transparent container, the transparent liquid is 1',, l K:ll=teish, this liquid tank S
The object to be inspected (all, , e, is a container) 6 is a person at the bottom of the
6. The interior of the □ is filled with high-pressure gas compared to the atmosphere. Therefore, if there is a leak in this inspected object B, air bubbles will be generated. Further, 7 is a condensing device which receives light from a wide range formed by the polygonal mirror 3 and supplies it to a photoelectric device g consisting of a phototransistor and the like.
□ Fig. 2 shows another embodiment L1 □ In this embodiment, 1,000 light 1' is partially formed in the lateral direction without scanning the V, - laser beam as in the case of Fig. 1. 6, and the parts corresponding to those of the apparatus in FIG. 1 are indicated by the same symbols. In this example, the kamabot-shaped lens star can be used completely, and the laser oscillator l
The laser beam from the front curtain is expanded in the horizontal direction to form a fan-shaped front curtain t'.

The above two methods look visually the same, but in the scanning method of FIG. 1, the energy density is high, but the contact time with the bubble is instantaneous. However, it is advantageous when extracted as an electrical signal. ,,-force 2. The system shown in Figure C has a simple structure because it does not have any moving parts, but the energy is divided and dispersed and the amount of dust and dirt is low, so there is little need to increase the sensitivity of the photodetector.

This will help you even if noise, noise, or a spoon becomes a problem. Therefore, you should choose whether to use the 154-sized chair or not, depending on the purpose of the call. It is considered that the method shown in FIG. 1 is advantageous for those of the -force/1) type, or the method shown in FIG. 2 for those with less requirements. .

Since the beam scanning method shown in FIG. 1 can also be visually regarded as a q-front curtain, in the following explanation of the operation of the double-edge type, both the double-edged type will be explained as the front curtain.

FIG. 3 shows how the bubble 10 passes through the leading curtains q and q/ from bottom to top. .

As shown in FIG. 3(a), the first curtain <11. ,, ,t
When the bubble IO comes into contact with the lower part of the laser beam 7, a portion of the laser beam is refracted 7 and proceeds in the direction indicated by the arrow i<5. , and the bubble 10 rises to the front curtain (ge, q) as shown in (b).
′) When the particles reach the hole, they scatter diagonally toward the upper blade and downward as shown by the arrows //, /, and 2.

Furthermore, when the bubble 10 comes to the position shown at (0), scattered light shown by the arrow 12 is generated. Therefore, in the direction of the force of movement of the bubble IO, the gravity region of the bubble IO becomes dark as the bubble rises. This situation is shown in Figure D. Figure q shows the light pattern created by a screen placed behind the screen.2. If there is no bubble IO, nothing will be visible, but as shown in the figure, when the bubble 10 reaches the front curtain (, 11, , <z'), a notation of light is formed. This changing state is detected by a photoelectric device g via a light condensing device to detect bubbles.

FIG. 5 shows a detection method using scattered light, which is used for the above-mentioned light detection. In this case, the concentrator removes the direct path of the laser beam and directs it upward (
Also, ti) is arranged below (the upper arrangement is shown in Fig. S), and the beam traveling straight is absorbed by the black body 13.

In addition, when detecting by the strength of the laser beam itself, the first
Using the beam scanning method shown in the figure, the condenser 7 is placed on the straight path of the laser beam.

The large curtain of the laser beam and the sharpness of the object to be inspected are carefully considered to ensure that bubbles coming from any part can be detected. Although a laser has been used as a light source because the beam thickness can be arbitrarily set to 11Al and has a high energy margin, it is of course possible to use other light sources depending on the case.

Furthermore, in the embodiment shown in FIG. 2, a kamabot-shaped lens is used as a means for diffusing the laser beam in the horizontal force direction, but it is of course a lens system that can diffuse the beam on one plane. Any lens may be used.

Figure 6 shows an example of application of this invention, and is an example of industrial use of this system. , in order, liquid m16. It is designed to move inside. Liquid tank/S
is a partition plate/6. It is divided into a washing section/g1, a settling section/9 and a shaving section 5 by /. The cleaning part/g is a flowing water and is designed to remove air bubbles and other foreign matter adhering to the outside of the object to be inspected, and the settling part/g is a flowing water to the detection part 20. Acts to avoid the effects.

The detection section 20 is provided with a transparent window t'1, and the above-mentioned bubble detection device is arranged to detect bubbles. If air bubbles are detected, use some method, for example, memorize the entire number of the arm /4/ on which the object to be tested on which air bubbles were detected, and remove that object in the subsequent sorting process. get it.

As explained above, according to the present invention, bubble detection can be easily performed with extremely high measurement accuracy, and it can be easily implemented as an automated system for leak inspection regardless of whether it is large scale or small scale. It is industrially very suitable for old men.

[Brief explanation of drawings]

Figures 3 and 3 are principle diagrams showing two embodiments of the bubble detection device according to the present invention. The diagrams are illustrated by H, Part S.
The figure is a schematic diagram showing a modification of the tN, and the figure is a schematic diagram showing an application example of the present invention. In the figure, l: laser oscillator, 3: polygonal mirror, front curtain, S: liquid tank, 7: condensing load, g: photoelectric device, W: semicylindrical lens. Figure 2 Procedural Amendment (Method) Date: Showa era - April 4, Mr. Commissioner of the Patent Office ■, Indication of the case, 1982 Patent Application No. 164,117 2, Title of invention Air bubble detection device 3, Amendment Relationship with the case of a person who does Bussan Building Annex Tel: (591) 02611, Specification 2, Drawing 6° Amendment details

Claims (1)

[Claims] l A front curtain forming device that horizontally irradiates a thin laser beam from a laser oscillator onto a transparent liquid tank to form a horizontal laser beam base, and It has a photoelectric device that detects two changes caused by the scattering of the laser beam by Σ bubbles floating in the liquid from the laser beam that has passed through it, and detects the presence or absence of bubbles and their size from the electrical output signal of the photoelectric device. A bubble detection device characterized by being able to detect the size and number of bubbles. ″ □ U Front curtain formation □ Laser from a laser oscillator is applied to the device
8. Apparatus according to claim 7, comprising a rotating polygon mirror arrangement for scanning the beam in a horizontal transverse force direction in a transparent liquid. '(3) The device according to item 7 of the patent application, in which the leading curtain forming device comprises a lens system that horizontally spreads the laser beam from the laser oscillator.