JP4090480B2 - Chemical substance emission measuring device - Google Patents

Description

  The present invention relates to a chemical substance emission measuring device for measuring the quantity of chemical substances contained in materials and the like.

  In recent years, it has been pointed out that chemical substances such as formaldehyde released from residential members contaminate indoor air in the house and contribute to so-called sick house syndrome. Therefore, it is necessary to clarify the amount of chemical substances emitted from materials such as building materials. As a measuring method, JIS A 1901 “Measurement method for volatile organic compounds (VOC), formaldehyde and other carbonyl compounds in building materials” “Small chamber method” is defined.

  In this small chamber method, building materials to be measured are installed in a chamber with a capacity of 20 to 1000 L, clean air is continuously supplied and ventilated, and the amount of chemical substances contained in the exhausted air is measured. By doing this, it is a method of measuring the amount of chemical substances emitted from the building materials to be measured. Nowadays, a cylindrical stainless steel chamber (capacity 20 L) having a diameter of 200 mm and a height of 300 mm is widely used, and various measuring apparatuses have been proposed so far (see, for example, Patent Documents 1 and 2).

In the above-described small chamber method, since the mass transfer rate inside the chamber affects the measurement result, it is desirable to control the air flow and wind speed inside the chamber that controls the mass transfer rate. For this reason, conventionally, a fan for stirring the inside of the chamber has been installed as a method for controlling the temperature, humidity, and wind speed inside the chamber. In order to prevent contamination by chemical substances that are not the object of measurement, this fan is mainly a magnet-molded ethylene tetrafluoride resin stirrer with blades used as a rotor. A stirrer was installed as an external drive device, and the rotational force was obtained without contact. At this time, the rotor was brought into point contact with the bottom surface of the chamber by a protrusion made of ethylene tetrafluoride resin or a steel ball of the rotor to prevent the rotation from being interrupted or stopped due to friction.
JP 2002-122521 A JP 2004-347476 A

  However, since the above method is a long-time test of up to 28 days, there is a problem that the contact portion of the rotor with the bottom surface of the chamber is worn, and the wear powder is scattered and contaminated inside the chamber. Further, since the force for holding the rotor is only the magnetic force of the magnetic stirrer, there is a problem that the rotation stops due to the interference of the rotation due to friction or the deviation from the central axis of the rotation. For this reason, there is a problem that not only stable measurement can be performed, particularly in long-term measurement, but also the measurement itself becomes invalid in some cases.

  Further, in order to stir stably for a long time, a method of making a hole in the bottom surface of the chamber and directly connecting the rotor to a driving device such as a motor can be considered. However, in order to maintain the airtightness of the chamber, an airtight structure such as a mechanical seal is required. Generally, grease or the like is used, so that the risk of contaminating the inside of the chamber is extremely high. In addition, it has been extremely difficult to disassemble, clean, and heat the rotor and to prevent contamination during measurement.

  In view of the above background, the present invention has an object to provide a chemical substance emission measuring device capable of controlling the wind speed stably for a long time without contaminating the inside of the chamber.

The present invention solves the above-mentioned problems. First, a rotary stirrer for stirring the air inside the chamber is provided at the bottom of the chamber, and the rotary stirrer is driven by magnetic force. magnetic stirrer of the apparatus the chamber - that are provided outside, in the chemical emission amount measuring device for measuring the emission rate of the air of chemical substances contained in materials, rotating the stirring member is a rotating stirrer and a rotary stirrer holder, rotating stirrer is formed integrally of a magnetic stirring element which rotates in response to the magnetic force of the magnetic stirrer and the rotor fixing shaft for fixing and holding the magnetic stirring element, rotary stirring child holding unit includes a bearing for rotatably supporting the rotor fixing shaft of the rotary stirrer and a bearing holding portion for holding the bearing of the bearing holding portion Yanba bottom are composed of a support arm for supporting the, the rotation stirrer at a rotation speed corresponding to the magnetic force of the magnetic stirrer rotating at a rotational stirrer holder, allowing control the speed of the wind chamber inside the gas It is characterized by.

Second, in the chemical substance emission measurement apparatus, the plurality of support arms are provided from the bearing holder to the chamber inner peripheral surface so that the rotation position of the rotary stirring member is positioned at the approximate center of the chamber bottom. The bearing holding portion is supported by extending toward the end.

Thirdly, in the above-mentioned chemical substance emission measuring device, a positioning pin is disposed at the bottom of the chamber, and a fitting portion fitted to the positioning pin is provided on the support arm extending from the bearing holding portion. provided on the distal end portion, the support arm is fixed by fitting the positioning pin and the fitting portion bearing holding part is characterized Rukoto supported.

According to the first aspect, the rotating stirring member comprises a rotary stirrer holder with rotating stirrer, rotating stirrer is fixed magnetic stirring element which rotates in response to the magnetic force of the magnetic stirrer and the magnetic stirring element a rotor fixing shaft for holding is formed integrally from the rotating stirrer holder includes a bearing for rotatably supporting the rotor fixing shaft of the rotary stirrer and a bearing holding portion for holding the bearing this It consists of a support arm that supports the bearing holding part at the bottom of the chamber , and the rotating stirrer rotates at the rotating stirrer holding part at a rotation speed corresponding to the magnetic force of the magnetic stirrer to control the air velocity of the gas inside the chamber. by that enabled, the chamber - it is possible for a long time stable control of the wind without contaminating the inside.

According to the second aspect of the present invention, the plurality of support arms are extended from the bearing holding portion toward the inner circumferential surface of the chamber so that the rotation position of the rotary stirring member is located at the approximate center of the chamber bottom. By supporting the part , the bearing holding part can be supported more effectively and the air speed inside the chamber can be controlled with higher accuracy.

According to the third aspect of the invention, the positioning pin is disposed on the bottom of the chamber, and the fitting portion that fits with the positioning pin is provided at the tip of the support arm that extends from the bearing holding portion, the Rukoto the support arm is fixed by fitting the support is bearing retaining part of the positioning pin and the fitting portion, in addition to the effects of the second invention, it is possible to support the bearing holding portion more reliably.

[First embodiment]
The present invention has the above-described features, but the best mode for carrying out the invention will be described below with reference to the drawings. FIG. 1 is a perspective view for explaining a rotary stirrer provided inside a chamber in the present invention, and shows a state where members of the rotary stirrer are disassembled outside the chamber. FIG. 2 is an enlarged perspective view of the rotary stirring body of FIG.

The chemical emission measuring apparatus of the present invention is an apparatus for measuring in accordance with JIS A 1901 "Measurement method for volatile organic compound (VOC), formaldehyde and other carbonyl compound emission of building materials-small chamber method". A rotating stirrer for stirring the air inside the chamber A is provided inside the chamber A, and a driving device (not shown) for driving the rotating stirrer is provided outside the chamber A. Thus, the rotating agitator and the driving device are disposed in a non-contact manner. The rotary stirrer includes a rotary stirrer 1 and a rotary stirrer holding unit 2, and the rotary stirrer 1 includes a rotor 11 and a rotor fixed shaft 12 that holds and holds the rotor 11. The rotary stirrer holding unit 2 includes a bearing 21 that rotatably supports the rotor fixing shaft 12, a bearing holding unit 22 that holds the bearing 21, and a support arm 23 that supports the bearing holding unit 22 in the chamber A. And disposed on the inner surface of the chamber-A. For example, a rotating stirrer made of each member shown in FIG. 1 is disposed at the bottom of the chamber A, and a sample table B made of a perforated plate on which a building material or the like to be measured is placed. Will be established. The rotating stirring body is disposed at the bottom of the chamber A as shown in FIG.

  The chamber A conforming to JIS A 1901 is used, and the shape thereof is not limited to the cylindrical shape as shown in FIG. 1, but may be a rectangular tube shape. Or it is good also as a shape according to the actual room shape, for example. In this case, measurement can be performed closer to actual conditions. The material is not particularly limited as long as it is a material that can prevent the diffusion and adsorption of chemical substances as much as possible, and examples thereof include stainless steel, quartz glass, and borosilicate glass.

  An example of a drive device that drives the rotary stirrer in a non-contact manner is a magnetic stirrer, and a magnetic stirrer 111 for a magnetic stirrer can be used as the rotor 11 of the rotary stirrer at this time. . In order to stir the air in the chamber A more effectively, the magnetic stirrer 111 may be provided with a blade 112 made of stainless steel, for example. 1 and 2, a star-shaped stirrer 111 'having a convex portion in a cross direction is used, and a blade 112 is attached and fixed to each convex portion along the cross direction. The magnetic stirrer 111 is considered to be a stirrer made of, for example, a tetrafluoroethylene resin molded with a magnet.

  The rotor fixing shaft 12 is formed of, for example, ethylene tetrafluoride resin, and is fixedly held at the lower part of the rotor 11 by screwing or the like, and is integrated with the rotor 11 to form the rotating stirrer 1. Is pivotally supported. That is, the rotor fixed shaft 12 is slid and rotated by the bearing 21. For this reason, the rotary stirrer 1 can suppress friction during rotation as much as possible, and can rotate stably for a long time. Then, the air in the chamber A can be more effectively agitated to control the wind speed.

  Examples of the bearing 21 include a ball bearing and a roller bearing, and are not particularly limited.

  The shape of the bearing holding portion 22 in the rotary stirrer holding portion 2 is a shape that matches the shape of the bearing 21, and it is considered that the bearing 21 can be fitted and fixed.

  The support arm 23 is not particularly limited in its shape as long as it supports the bearing holding portion 22 in the chamber A and positions the rotational position of the rotary stirring member at the approximate center in the chamber A. For example, as shown in FIGS. 1 and 2, a plurality of support arms 23 may be extended from the bearing holding portion 22 toward the inner peripheral surface of the chamber-A. When the chamber A is cylindrical, the support arms 23 are provided so that the angles formed by the adjacent support arms 23 are substantially uniform, and the length of each support arm 23 is substantially in contact with the inner peripheral surface of the chamber A. By setting, the rotational position of the rotary agitator can be positioned substantially in the center of the chamber A. In FIGS. 1 and 2, three support arms are used with the angle between adjacent support arms 23 being approximately 120 degrees. However, the present invention is not limited to this, and two or four or more support arms 23 are used. May be.

The material of the rotor fixing shaft 12, the bearing 21, the bearing holding portion 22, and the support arm 23 is made of stainless steel, four-way stainless steel, four in order not to contaminate the inside of the chamber A and to be cleaned by cleaning and heating. It is preferable to use ethylene fluoride resin, ceramic, glass or the like.
[Second Embodiment]
The support arm 23 in the chemical substance emission measuring device according to the present invention is not limited to the support arm 23 extended toward the inner peripheral surface of the chamber A as shown in FIGS. 1 and 2, but as shown in FIG. You may make it provide the fitting part 231 in a front-end | tip part. At this time, it is necessary to dispose the positioning pin 3 at the bottom of the chamber (not shown in FIG. 3). That is, the support arm 23 is fixed in the chamber by fitting the positioning pin 3 disposed on the bottom of the chamber to the fitting portion 231 of the support arm 23. As a result, the bearing holding portion 22 can be more reliably supported. Of course, it is considered that the positioning pin 3 is disposed so that the rotational position of the rotary stirring member is located at the approximate center in the chamber. In FIG. 3, the positioning pin 3 is disposed so that a straight line connecting the two positioning pins 3 passes through the center of the chamber, and the two support arms 23 are directed from the bearing holding portion 22 toward the inner peripheral surface of the chamber. It is extended.

  In this embodiment, since the support arm 23 is fixed by fitting the positioning pin 3 and the fitting portion 231 of the support arm 23, the lengths of the support arms 23 and adjacent to each other as in the above embodiment. The angle formed with the support arm 23 does not need to be substantially uniform and can be set.

  It is considered that the material of the positioning pin 3 is the same as that of the support arm 23 described above. The shape of the positioning pin 3 is not limited to the cylindrical shape as shown in FIG. 3 as long as it can be fitted to the fitting portion 231 of the support arm 23 and can fix the support arm 23.

  Hereinafter, examples will be shown and described in more detail. Of course, the present invention is not limited by the following examples.

<Production of chemical substance emission measurement device>
A cylindrical stainless steel chamber (ADPAC-20L manufactured by Adtech Co.) having a diameter of 300 mm, a height of 300 mm, and a capacity of 20 L was used as the chamber.

  A commercially available magnetic stirrer for a magnetic stirrer with a diameter of 70 mm was provided with a rotor fixed shaft made of ethylene tetrafluoride resin fitted with a stainless steel blade and a bearing holding portion to obtain a rotary stirrer.

  A bearing with a casing made of ethylene tetrafluoride resin and a bearing ball made of stainless steel is installed in a stainless steel bearing holder (bearing holding part), and three supporting arms made of stainless steel are mounted on the bearing holder. It was installed so that the angle formed was 120 degrees, and a rotary stirrer holding part was obtained.

  A commercially available magnetic stirrer (SST-172 manufactured by Shimadzu Corporation) was used as the drive device installed outside the chamber.

The above is applied to a chemical substance emission measuring device (ADPAC-SYSTEM manufactured by Adtech Co., Ltd.) in accordance with JIS A 1901 "Measurement method for emission of volatile organic compounds (VOC), formaldehyde and other carbonyl compounds in building materials-Small chamber method". By incorporating it, a chemical emission measuring device capable of controlling the wind speed stably for a long period of time without contaminating the inside of the chamber was obtained.
<Performance evaluation>
(Reproducibility of chamber internal wind speed control)
The reproducibility of the air speed control inside the chamber was confirmed by measuring the air speed inside the chamber while changing the rotational speed setting of the magnetic stirrer. The wind speed was measured with a fine anemometer (ANEMOMASTER MODEL 1500: manufactured by Kanomax Co., Ltd.). Further, the rotational speed was measured with a stroboscope (manufactured by Sympo), and it was confirmed that the rotational speed setting of the magnetic stirrer and the actual rotational speed of the rotor matched.

  The rotational speed setting was changed stepwise from a low state to a high state, and then changed stepwise from a high state to a low state. The measurement results are shown in Table 1.

When the rotational speed is changed from a low state to a high state, and when the rotational speed is changed from a high state to a low state, almost the same wind speed can be obtained with the same rotational speed setting. The reproducibility was confirmed.
(Confirmation of stability during long-time operation)
The apparatus was operated continuously for 30 days, and the inside of the chamber was observed after 30 days. As a result, there was no scattered matter due to wear, and it was confirmed that the rotating stirrer was rotating stably in the same state as at the start of operation.
(Confirmation of problems in cleaning and heating)
The chamber was cleaned with pure water and then cleaned by heating and drying in an oven at 260 ° C., but there was no problem with the chamber structure. The rotary stirrer and the rotary stirrer holding part were cleaned by purifying with pure water and then heating and drying at 80 ° C. because the material contains ethylene tetrafluoride resin. There was no abnormality in the structure of the rotating stirrer and the rotating stirrer holding part, and there was no problem.

  After the cleaning and heating, the operation was performed for 1 day with clean air supplied, and the background concentration was measured by collecting the exhaust air from the chamber and measuring the chemical concentration. The background concentration is in accordance with JIS A 1901. For formaldehyde and other carbonyl compounds, dinitrophenylhydrazine solid phase adsorption / solvent extraction / high performance liquid chromatographic method is used for other VOCs (volatile organic compounds). Were measured by solid phase adsorption / heat desorption / gas chromatography with mass spectrometer. As a result, the concentrations of formaldehyde and other carbonyl compounds and other VOCs (detected in the range from n-hexane to n-hexadecane by the gas chromatograph method with a mass spectrometer) to be measured in JIS A 1901 are All were below the limit of quantification, and it was confirmed that cleaning by heating and heating was performed appropriately.

It is a perspective view for demonstrating the rotary stirring body provided in a chamber. It is the perspective view which expanded the rotary stirring body of FIG. It is a perspective view which shows another embodiment for fixing a support arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating stirrer 11 Rotator 111 Magnetic stirrer 111 'Star-shaped stirrer 112 Blade 12 Rotor fixed shaft 2 Rotating stirrer holding part 21 Bearing 22 Bearing holding part 23 Support arm 231 Fitting part 3 Positioning pin A Chamber
B Sample stand

Claims (3)

Chambers - the air inside rotating stirring member for stirring the the chamber - provided in the bottom of the, magnetic stirrer of the rotating stirring member as a driving device for driving the magnetic force chamber - that provided outside, materials The chemical stirrer for measuring the amount of chemical substance contained in the air, the rotary stirrer includes a rotary stirrer and a rotary stirrer holding unit, and the rotary stirrer is a magnetic stirrer. magnetic force are formed integrally of a magnetic stirring element which rotates with the rotor fixing shaft for fixing and holding the magnetic stir element according to the rotating stirrer holding portion rotatably rotor fixing shaft of the rotary stirrer Contact is composed of a bearing for rotatably supporting the the bearing holding portion for holding the bearing and supporting arms for supporting the bearing holder in the chamber bottom Rotates rotating stirring bar by the rotation stirrer holder at a rotational speed corresponding to the magnetic force of the magnetic stirrer, the chemical emission quantity measuring device is characterized in that the controllable wind speeds inside the chamber gas. A plurality of support arms are extended from the bearing holding portion toward the inner peripheral surface of the chamber so that the rotational position of the rotary stirring member is located at substantially the center of the chamber bottom, and the bearing holding portion is supported. The chemical substance emission amount measuring apparatus according to claim 1. A positioning pin is provided at the bottom of the chamber, and a fitting part that fits with the positioning pin is provided at the tip of the support arm that extends from the bearing holding part. chemical Determination of the emission device according to claim 2, the bearing holder is fixed support arm, characterized in Rukoto is supported by.