JP4904591B2 - Asbestos dust generation measuring device - Google Patents

Description

  The present invention relates to an apparatus for measuring asbestos dust generation from the surface of an asbestos-containing material.

As is well known, asbestos (asbestos) has been widely used in various fields including building materials in the past because it has excellent physical properties, but in recent years it is clear that the dust causes serious health damage. It has become a big social problem.
In order to take measures against asbestos dust, it is indispensable to grasp the concentration of asbestos dust in the ambient air. Therefore, the “Asbestos Monitoring Manual” has been formulated as a technical guideline for measuring the asbestos dust concentration in the ambient air. (Refer nonpatent literature 1).
“Asbestos Monitoring Manual (Revised Version)”, Air Quality Control Division, Air Quality Control Bureau, December 1993, p.1-6

The measurement method of asbestos dust concentration stipulated in the above manual measures the amount of asbestos dust in the atmosphere by sampling the atmosphere continuously for a long time at the measurement target point and passing it through a filter paper for collection (membrane filter). It is based on doing.
However, although such measurement methods can measure the average concentration in the atmosphere near the measurement target point, for example, the amount of dust generated from a specific building material can be measured directly or the location of dust generation can be specified. There is nothing you can do.
Therefore, the above measurement method alone is not always sufficient, and in taking higher measures, not only the average concentration measurement in the ambient air, but also the asbestos dust from specific members is directly measured. In addition, it is necessary to establish a measurement method that can measure the possibility of asbestos dust generation and the degree of deterioration of building materials that would lead to it.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate measuring apparatus capable of directly measuring the amount of asbestos dust generated from the surface of an asbestos-containing material.

  The present invention is an apparatus for measuring the amount of asbestos dust generated from a specific part of the surface of an asbestos-containing object, a cover that covers the periphery of the part to be measured in an airtight manner, and absorbs air in the cover. An intake pipe for suction, a membrane filter mounted on the tip of the intake pipe and disposed in the cover, for collecting asbestos dust in the intake air sucked by the intake pipe, and a proximal end of the intake pipe A connected intake pump, a flow meter for measuring the amount of intake by the intake pump, and the cover are provided so as to inject air outside the cover from the tip thereof to the measurement target portion by the suction force of the intake pump And a membrane filter attached to the base end portion of the injection tube.

According to the measuring apparatus of the present invention, the measurement target part is covered with a cover, and air is sucked from the inside through the intake pipe by the intake pump, whereby the air outside the cover is sucked into the cover through the injection pipe by the suction force. Can be sprayed onto the measurement target member, and dust can be forcedly generated from the measurement target site by the jet air flow, and the total amount of dust generation can be collected by the membrane filter attached to the tip of the intake pipe .
And by measuring the amount of asbestos collected by forced dust generation, the amount of asbestos dust from the measurement target part can be quantitatively determined in association with the intake air amount, and the same measurement at each part It is possible to quantitatively compare the amount of asbestos dust from each part by performing under the same conditions, and it is possible to estimate and grasp the presence and degree of deterioration of each part, and the result is asbestos-containing material Can be used effectively when dismantling and repairing.
Of course, measurement is performed with the measurement target part covered in an airtight manner with a cover, and the total amount of asbestos that has been forcibly dusted is collected by the membrane filter, and a membrane filter is also attached to the base end of the injection tube. Therefore, it is possible to surely prevent asbestos from being scattered around during measurement, and a highly accurate and safe measurement operation is possible.

  FIG. 1 is a schematic configuration diagram of a measuring apparatus according to an embodiment of the present invention. This is because various asbestos-containing materials, for example, structural members such as steel beams having a fireproof coating with asbestos on the surface as shown in the example shown in FIG. The cover 2 that covers the periphery of the measurement target part in an airtight manner, the intake pipe 3 that can suck the air in the cover 2, and the tip of the intake pipe 3 A collecting mechanism 4 that is disposed in the cover 2 and collects asbestos dust in intake air, an intake pump 5 connected to the proximal end of the intake pipe 3, and a flow rate that is built in the intake pump 5 and measures the intake air amount. A total of 6, an injection pipe 7 that is provided through the cover 2 and blows air outside the cover 2 from the tip of the cover 2 to the measurement target site by the suction force of the intake pump 5, and a base end portion of the injection pipe 7 And a collection mechanism 8 mounted.

The cover 2 in this embodiment is a box-shaped or cup-shaped with one open surface, and the material thereof is appropriate, but for example, a vinyl chloride material, an acrylic material, or a metal material can be suitably employed. If a seal member 9 made of a flexible material such as silicon rubber is attached around the opening, no gap is generated even when the surface of the measurement object has irregularities or unevenness.
In FIG. 1, a stand 10 consisting of a tripod with an adjuster 10a for height adjustment is used to support the cover 2 from the floor surface and press it against the lower surface of the object 1 to be measured. The form of attachment of the cover 2 to the object 1 may be changed as appropriate according to the position and orientation of the measurement target part, and if possible, the cover 2 may be pressed manually by an operator.

For example, a flexible pipe material having an inner diameter of about 6 mm can be suitably used as the intake pipe 3, and the tip thereof is a connection pipe 3 a having the same diameter and penetrates the cover 2 in an airtight manner. The collecting mechanism 4 is connected to the tip and disposed in the cover 2.
The collection mechanism 4 has a structure in which a membrane filter is built in the holder. For example, a known open face type holder having a diameter of 25 mm can be suitably used, but in any case, the total amount of asbestos dust in the intake air can be reduced. Use something that can be collected.

The intake pump 5 sucks a desired amount of air from the cover 2 through the collection mechanism 4 and the intake pipe 3 and, along with that, sucks air into the cover 2 through the injection pipe 7 and injects it to the measurement target site at a predetermined wind speed. And has a suction force necessary for that purpose.
In the illustrated example, the flow meter 6 is integrated into the intake pump 5, but the flow meter 6 may be prepared separately from the intake pump 5 and connected to the suction side or the discharge side of the intake pump 5. .

For example, a metal tube having an inner diameter of about 3 to 6 mm can be suitably used as the ejection tube 7, and the cover 2 penetrates the cover 2 in an airtight manner and the distal end thereof faces the measurement target site. 4 is equipped with a collection mechanism 8 incorporating a membrane filter.
Therefore, by operating the intake pump 5, the air outside the cover 2 is cleaned through the collection mechanism 8 by the suction force and then sucked into the injection pipe 7. The asbestos on the surface of the measurement target part is forcibly blown off by such a jet air flow, and dust generation can be forcibly generated in the cover 2.
The injection flow rate of the injection air flow from the injection tube 7 may be set as appropriate. For example, when the inner diameter of the injection tube 7 is 3 mm, the injection flow rate may be 5 m / s. Specifically, it becomes 2.1195 L / min, but if there is no leakage, it matches the intake amount by the intake pump 5 (measured value by the flow meter 6).

Measurement by the measuring apparatus having the above-described configuration is performed by attaching the cover 2 to the measurement target portion, covering the periphery thereof in an airtight manner, operating the intake pump 5 and sucking the air in the cover 2 through the intake pipe 3.
As a result, as described above, the jet air flow from the jet pipe 7 is blown to the measurement target portion at a predetermined wind speed, the asbestos in the surface layer portion is blown off, a minute amount of dust is generated, and the asbestos dust scattered in the cover 2 is The air is sucked into the collecting mechanism 4 together with the air in the cover 2 to collect the whole amount, and only clean air after the asbestos dust is collected is sucked into the intake pump 5 and exhausted outside the system.
Therefore, after the operation for a predetermined time, the operation is stopped and the membrane filter is taken out from the collection mechanism 4 and analyzed to measure the collection amount (that is, the amount of asbestos dust forcedly generated). Further, the intake air amount during the operation time is measured by the flow meter 6.

  As described above, the asbestos dust amount forcibly generated from the measurement target site by the jet air flow can be directly and quantitatively obtained in association with the intake air amount (= the jet air amount). Therefore, it is possible to quantitatively compare the amount of asbestos dust from each part by performing the same measurement at each part under the same conditions, and from this, quantify the amount of dust generated from each part. It is possible to grasp the degree of deterioration of each part, and to estimate the degree and degree of deterioration of each part, and it is possible to effectively use the measurement results when disassembling and repairing asbestos-containing materials.

Of course, although asbestos is forced to generate dust, the part to be measured is covered with a cover 2 in an airtight manner, and dust is generated only inside it. The total amount of asbestos that has been forcibly generated is captured. The collection mechanism 4 (membrane filter) can be completely collected, and the injection tube 7 is also provided with a similar collection mechanism 8 so that not only the outside air sucked into the injection tube 7 is naturally cleaned, Asbestos dust that is forcibly generated at the time of measurement is not inadvertently scattered to the surroundings through the injection pipe 7, and it is possible to perform not only high accuracy but also safe measurement.
Moreover, the overall configuration of the device is extremely simple and can be manufactured at a low cost by combining inexpensive general-purpose products, and the measurement work does not require any troublesome and complicated procedures, and can be easily performed by one worker. From the above, it is extremely effective as a tool for diagnosing the degree of degradation of asbestos-containing materials.

In the case where asbestos is sprayed as a fireproof coating on the structural member as in the above embodiment, as exemplified above, the injection pipe 7 having an inner diameter of 3 to 6 mm is used to provide 5 m / s. Although it is considered that it is preferable to spray at a jet flow rate of the order, the setting of the diameter of the jet tube 7 and the jet flow velocity from there is in consideration of the material and application of the measurement object, the measurement purpose, and other various conditions. What is necessary is just to set arbitrarily, especially about the injection flow velocity, for example, what is necessary is just to set freely in the range from the slight wind speed of about 0.5 m / s to the strong wind speed of about 15 m / s.
In any case, if the inner diameter of the injection pipe 7 and the injection flow velocity are determined, the amount of injection air per unit time (= the amount of intake air from inside the cover 2) is theoretically determined, and then the measurement time is determined. Since the total amount of air supply during measurement is naturally determined, if the diameter of the injection pipe 7 and the injection flow velocity are fixed, the measurement can be performed using only the measurement time as a parameter without directly measuring the intake air amount. Therefore, when a large amount of dust is expected, the operation time should be shortened and adjusted so that excessive asbestos does not adhere to the membrane filter. The amount can be measured with high accuracy.

It is a schematic block diagram of the measuring apparatus which is embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measurement object 2 Cover 3 Intake pipe 3a Connection pipe 4 Collection mechanism (membrane filter)
5 Intake pump 6 Flow meter 7 Injection pipe 8 Collection mechanism (membrane filter)
9 Seal member 10 Stand 10a Adjuster

Claims (1)

A device for measuring the amount of asbestos dust from a specific part of the surface of an asbestos-containing material,
A cover that covers the area to be measured in an airtight manner,
An intake pipe for sucking air in the cover;
A membrane filter that is attached to the tip of the intake pipe and disposed in the cover, and collects asbestos dust in the intake air sucked by the intake pipe;
An intake pump connected to the proximal end of the intake pipe;
A flow meter for measuring the amount of intake by the intake pump;
An injection pipe that is provided through the cover and blows air outside the cover from its tip to the measurement target site in an injection state by the suction force of the intake pump;
An asbestos dust generation measuring device comprising a membrane filter attached to a base end portion of the injection pipe.

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