JPH05172687A - Method for detecting leak place - Google Patents

Abstract

PURPOSE:To certainly specify the position of a pinhole by filling an airtightness required structure with colorable smoke under pressure in a state possible to flow out and detecting the coloration of the surface of the airtightness required structure generated by the outflow of the smoke. CONSTITUTION:The smoke of tobacco 6 flows in the hollow yarns 10 of a dialyzer 1 by operating an air supply pump 7 to raise the pressure of a pressure gauge 8. The internal pressure of the pressure gauge 8 is held to about 0.1-1.5kg/cm<2> and the smoke of the tobacco 6 is allowed to flow for a time burning about two tobaccos 6. When a pinhole is present, the casing 9 of the dialyzer 1 is filled with the smoke leaking from the hollow yarns 10 and the smoke issues from the opening 11 of the tubular part provided to the casing 9 and, therefore, the presence of a leak place is cleared. After the smoke of the tobacco 6 is allowed to flow for a predetermined time, the dialyzer 1 is detached from a tube to observe the hollow yarns 10. At this time, the region colored with a blackish dark color is a leak place. By this constitution, a leak place can be easily specified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak location detecting method, and more particularly to a leak location detecting method capable of easily detecting a leak location by simply using colored smoke.

[0002]

BACKGROUND OF THE INVENTION Generally, airtight components are tested after manufacture for the presence of leaks such as pinholes. Good and bad products are selected by the test, and the airtight components where leaks are found are discarded as defective products. Furthermore, the detection of a leak location can be a clue to elucidate the cause, and elucidation of the cause can improve the manufacturing process, prevent the generation of defective products, and increase the manufacturing efficiency. Therefore, the detection of leak points plays an important role in manufacturing and quality control of products having airtight components. As a method of detecting a leak location, for example, there is a method of detecting the presence or absence of bubbles by filling air into the tire tube and immersing it in water, such as a method of detecting a pinhole of a bicycle tire tube. ..

However, according to the above-mentioned method, the presence or absence of extremely fine pinholes generated in a hollow fiber bundle or the like filled in a dialyzer for blood purification, which is a thin member incomparable to a tire, exists or not. Has the drawback that it can detect but cannot locate. Therefore, with the above method, although it is possible to select good products and defective products, it is not possible to identify the location of the pinhole, so the cause cannot be clarified,
There is a problem that it is not possible to improve the process for producing a pinhole-free hollow fiber with a good yield. Therefore, the present invention, in various structures that must be airtight, it is possible to reliably identify the position of the pinhole, useful in improving the manufacturing process and quality control of the structure having an airtight member, The purpose is to provide a simple method.

[0004]

A method for detecting a leak point according to the present invention for solving the above-mentioned problems is produced by pressurizing and filling colored smoke into an airtight constituent body so that the smoke can flow out. It is characterized in that the coloring of the surface of the airtight constituent body is detected. Examples of the colored smoke include smoke that causes the surface to be colored by the smoke when contacted with an object for a predetermined time, for example, a smoke containing a tar component. Also, the color at the time of coloring should be a colored smoke that can distinguish the other part from the leaked part,
The color to be colored with smoke can be appropriately selected according to the member used.

The colored smoke can be generated by incomplete combustion of organic matter. As a method of incomplete combustion, it suffices if oxygen can be supplied insufficiently to achieve incomplete combustion. For example, various methods such as burning organic matter inside a bottomed cylindrical container with an open top surface can be used. It can be appropriately selected. As the organic substance, a plant or animal substance can be used. As the plant organic substance, a plant- or plant-derived substance, object or product can be used. Examples of the plant organic matter include tobacco, mosquito coil, wood, dead leaf, rice, straw, cotton, silk, paper, petroleum, coal or their extracts, refined products, or a mixture thereof.

[0006] As the above-mentioned animal organic substance, a substance, object or product of animal origin or animal origin can be used. Examples of animal organic substances include fats and oils, heads,
Examples include lard, fish oil, wax, and mixtures thereof. Among these, cigarettes are preferable. Particularly preferred cigarettes include cigarettes without cigars, cigars, cigarettes for kissels, cigarettes for pipes, etc. that do not absorb and filter tar components contained in smoke. In addition, as a cigarette without a filter, the product name is, for example, "piece" of both sides.
(Registered trademark), "Shinsei" (registered trademark), and the like.

The time for coloring depends on the type of selected colored smoke, the material and color of the airtight component, etc.
The time required for coloring the leaked area due to colored smoke to be distinguishable from other areas is sufficient.For example, when coloring a transparent hollow fiber fiber bundle with cigarette smoke, about two cigarettes are burned. The time required for is sufficient. The airtight constituent is not limited in its shape as long as it is airtight, and for example, a cylinder, a flat membrane, a hollow fiber membrane, a capillary or the like that allows smoke to flow inside. If so, any form may be used. The smoke passage is also straight,
It may be S-shaped, L-shaped or any other distribution shape.

As the material of the airtight component, various materials such as plastic, glass, rubber, metal, synthetic resin and leather can be used. Also,
The color of the airtight component is not particularly limited, but a transparent color or a bright color such as white is particularly preferable. The air-tightness-requiring constituent may be constituted alone such as a tube or a hollow fiber, or may be constituted as an aggregate thereof such as a hollow fiber bundle of a dialyzer, or two or more. It may be configured by a member, a seal portion such as an O-ring or packing is provided at the connecting portion, and the connecting portion is fitted.

As for the method of filling under pressure, in the case of an airtight structure having both ends open, for example, one end of the opening is closed, and the other end is colored with a colored smoke by using an air supply pump. A method of sending air containing air into the airtight structure for pressure filling, or sending air containing colored smoke into the airtight structure from the openings at both ends using an air pump at the same time. Various methods such as pressure filling can be appropriately selected. Further, in the case of an airtight structure whose one end is open, first, air containing colored smoke is sent from the opening into the structure by an air supply pump to replace the internal air with smoke and then pressurize. Various methods such as a method are possible.

The degree of pressurization is appropriately selected depending on the strength and durability of the structural body, and a pressure that allows colored smoke to flow out from the pinhole is sufficient. In the case of a hollow fiber bundle of a dialyzer, for example, 0.1 to 1.5 Kg / cm ² is preferable. As a method of confirming whether or not pressure is applied, a closed system part in a colored smoke flow path, for example, a space in which one end is blocked with a pinch cock or the like and the other end is blocked with a pump or the like is used. It can be measured by providing a pressure gauge or the like in part.

A pump or the like can be used as a method for sending the air containing the colored smoke into the airtight constituent body. Various types of pumps can be used,
For example, various pumps known per se such as a diaphragm pump, a plunger pump, a tube type roller pump, and a peristaltic pump can be used. As a method of detecting the coloring, a method of detecting with the naked eye can be used, and if necessary, a magnifying glass such as a loupe, a microscope or the like can be used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the leak location detecting method according to the present invention will be described below with reference to the drawings. (Example 1) FIG. 1 is an example in which the method of the present invention is applied to a hollow fiber of a dialyzer. —Preparation— The liquid inlet / outlet portions 2 located at both ends of the dialyzer 1 are joined to one end openings of the tubes 3a and 3b made of rubber or silicon. An appropriate portion of one tube 3a is tightened with a tightening means 4, such as a pinch cock, a screw cock, a clamp or a string, or the other end opening is closed with a plug 5. The other tube b has one or more cigarettes 6 etc. after ignition at the opening at the other end,
Insert it with as little space as possible, and install an air supply pump 7 such as a diaphragm pump, a plunger pump, a tube type roller pump or a peristaltic pump in an arbitrary flow passage between the cigarette 6 and the dialyzer 1.
Further, the pressure gauge 8 is provided with the air supply pump 7 and the dialyzer 1.
It is attached to the tube 3a between the.

-Operation-When the air supply pump 7 is operated, the smoke of the cigarette 6 flows into the hollow fiber 10 of the dialyzer 1, and after a while, the pressure of the pressure gauge 8 rises. Internal pressure is 0.1-1.5K
A positive pressure of about g / cm ² is maintained, and the smoke is let flow for about two cigarettes 6 to burn out.

-Presence and Identification of Leakage Point-If a pinhole exists, the casing 9 of the dialyzer 1 is filled with smoke leaking from the hollow fiber 10, and the smoke is leaked from the opening 11 of the tubular attachment portion. Indicates that there is a leak. After blowing the smoke of the cigarette 6 for a predetermined time, the dialyzer 1 is removed from the tube, and the hollow fiber of the dialyzer 1 is observed with the naked eye or a magnifying glass. Since the portion colored in dark color such as black is the leak portion, the leak portion can be easily specified.

[0015]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned structure, it is possible to easily detect a leak location such as a pinhole in the airtight structure by the presence or absence of smoke outflow, and to select a good product or a defective product. You can Furthermore, since the leaked spots are colored by the outflow of colored smoke, it is possible to identify the leaked spots easily and reliably with the naked eye, and to improve the process to manufacture hollow fibers without pinholes with good yield. It is possible to obtain excellent effects such as

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

[Explanation of sign]

 1 Dialyzer loaded with a hollow fiber bundle 2 Liquid outlet / inlet part 3 Tube 4 Clamp 5 Plug 6 Cigarette 7 Air supply pump 8 Pressure gauge 9 Cylindrical casing of dialyzer 10 Hollow fiber bundle 11 Opening of tubular attachment part

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[Procedure amendment]

[Submission date] January 7, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. A method for detecting a leak location, which comprises pressurizing and filling colored smoke into an airtight constituent body so that the smoke can flow out, and detecting coloring on the surface of the airtight constituent body caused by the outflow of smoke.