JP2018105820A - Method and device for measuring floating properties of particulate matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating property measurement method for particulate matter, which allows for measuring a floating property of particulate matter that can be a risk assessment index for the particulate matter, and to provide a floating property measurement device used for such a method.SOLUTION: A floating property measurement device comprises: an accommodating container capable of accommodating particulate matter; swirling flow generation means capable of generating a swirling flow inside the accommodating container; suction means that is provided on an upper portion of the accommodating container and is capable of sucking a gas in a central portion of the swirling flow and the particulate matter in the gas, and capturing means capable of capturing the particulate matter sucked by the suction means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a floating characteristic measuring method and a floating characteristic measuring apparatus for measuring the floating characteristic of particulate matter.

  Particulate matter has the property of floating in the air, and since it may be inhaled by humans and deposited in the trachea and lungs, there is a concern that it may cause health damage mainly in the respiratory system . In particular, a fine particulate material (PM2.5) having a particle size of 2.5 μm or less may cause alveoli and may cause serious health damage.

  Conventionally, in order to grasp the state of air contaminated with such particulate matter, the particulate matter in the air sucked by the suction device is collected after being sized by a cyclone type sizing unit, An air dust concentration measuring method for measuring the concentration of the collected particulate matter is known (Patent Document 1). According to the air dust concentration measuring method of Patent Document 1, it becomes possible to measure the concentration of particulate matter of a specific size in air containing various particulate matter of various sizes. When the particulate matter having a size to be measured can be specified in advance as being harmful to the living body, it can be an effective means for determining the presence or absence of air pollution.

JP 2006-121913 A

  By the way, with respect to particulate matter, there is no risk evaluation index indicating the effect of entering the living body, such as the vapor pressure of organic compounds. For this reason, in the past, it was only possible to make a vague assessment of harmfulness based on the size (particle diameter) of the particulate matter, and for each of the various types of particulate matter, the harmfulness to the living body was individually identified. There is a problem that you can't do it.

  This also applies to the air dust concentration measuring method disclosed in Patent Document 1. That is, in the air dust concentration measuring method of Patent Document 1, dust in the atmosphere is collected and the concentration thereof is measured, and the presence or absence of air pollution can only be vaguely determined. There is a problem that it is impossible to specify the particulate matter and measure the degree of harmfulness of the particulate matter.

  Therefore, the present invention provides a method for measuring the floating characteristics of particulate matter capable of measuring the floating characteristics that can serve as a risk evaluation index for the particulate matter, and a floating characteristic measuring device used in the method for measuring the floating characteristics. Objective.

  In order to achieve the above object, a method for measuring the floating characteristics of particulate matter according to the present invention includes a gas flow generation step for generating a gas flow containing particulate matter to be measured, and the particulate matter from the gas. A collecting step for collecting the substance, a concentration measuring step for measuring the concentration of the particulate matter collected by the collecting step, and a concentration measured by the concentration measuring step for the reference substance It is characterized by comprising a buoyancy coefficient measurement step for measuring the buoyancy coefficient of the particulate matter by comparing with the concentration.

  The method for measuring the floating characteristics of particulate matter according to the present invention further includes a sizing step of sizing ultrafine particles by turning the gas flow into a swirl flow before the collecting step, It is preferable that the ultrafine particles sized by the sizing step are collected as the particulate matter.

  Moreover, the floating characteristic measuring apparatus according to the present invention is a floating characteristic measuring apparatus used in the above-described floating characteristic measuring method, and a container that can store the particulate matter, and a swirl flow is generated in the container. Possible swirl flow generating means, suction means provided at the upper part of the container, capable of sucking the gas in the central part of the swirl flow and the particulate matter in the gas, and the sucked by the suction means It is provided with the collection means which can collect a particulate matter.

  In the floating characteristic measuring apparatus according to the present invention, it is preferable that the storage container is configured so that the inside thereof can be viewed from the outside.

  Further, in the floating characteristic measuring apparatus according to the present invention, the swirl flow generating means is a magnet type stirring blade disposed inside the storage container and the magnet type stirring blade disposed outside the storage container and magnetically. It is preferable to provide a magnetic stirrer capable of rotating the.

  According to the present invention, it is possible to provide a method for measuring a floating property of a particulate material capable of measuring a floating property that can be a risk evaluation index for the particulate material, and a floating property measuring apparatus used in the method for measuring the floating property. it can.

It is a schematic block diagram which shows schematic structure of the floating characteristic measuring apparatus which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the state which generated the swirling flow (aerosol) of the particulate matter using the floating characteristic measuring apparatus which concerns on this embodiment, and was sized, FIG.2 (a) is along the radial direction of a storage container. FIG. 2B shows a cross section along the axial direction of the container. It is a flowchart which shows the flow of the floating characteristic measuring method which concerns on this embodiment. 4 is a table showing measurement results of samples A to D and a control substance according to Example 1. It is a graph which shows the floating coefficient of sample AD which concerns on Example 1, and a control substance. It is a table | surface which shows the measurement result of sample EH which concerns on Example 1, and a control substance. It is a graph which shows the floating coefficient of sample EH which concerns on Example 1, and a control substance.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  As shown in FIG. 1, the floating characteristic measuring apparatus 1 according to the present embodiment generates a gas flow (aerosol) containing particulate matter to be measured and makes the gas flow a swirl flow to generate particles. A cyclone type sizing mechanism 2 for sizing particulate matter, a suction means 30 for sucking the gas at the center of the swirling flow and the particulate matter in the gas, and collecting the particulate matter sucked by the suction means 30 A collecting means 40 for performing the operation, and an arithmetic processing unit (not shown) for executing various arithmetic processes for specifying the floating characteristics.

  The cyclone type sizing mechanism 2 includes a storage container 10 that can store particulate matter (powder, dust), and a swirl flow generating means 20 that can generate a swirl flow inside the storage container 10.

  The container 10 includes a bottomed cylindrical container main body 12 having an open upper surface and a lid body 14 that can close the upper surface of the container main body 12, and the lid body 14 is attached to the container main body 12. In addition, a sealed space is formed inside. The container 10 is made of a material that hardly adheres particulate matter due to static electricity, such as glass or stainless steel, or an inner surface thereof is subjected to antistatic processing. Further, the storage container 10 is formed of a transparent material, or a transparent observation window or the like is formed in a part thereof, so that the inside thereof can be viewed from the outside.

  The lid 14 has an inflow portion 16 for allowing particulate matter to flow into the storage container 10, a gas flow (aerosol) inside the storage container 10, and particulate matter in the gas flow in the storage container 10. An outflow portion 18 is formed for flowing out. The outflow part 18 is formed substantially at the center of the lid body 14 and is configured to allow outflow of gas and particulate matter at a substantially central part of a swirling flow described later. The outflow part 18 is provided with a collecting means 40, and is configured so that the particulate matter in the gas flowing out from the outflow part 18 can be collected by the collecting means 40.

  The swirling flow generating means 20 is provided with a magnetic stirring blade 22 disposed inside the storage container 10 and a magnetic stirrer 24 disposed outside the storage container 10 and capable of rotating the magnetic stirring blade 22 by magnetic force. And rotating the magnetic stirring blade 22 by the magnetic force of the magnetic stirrer 24 to generate a swirling flow (cyclone) inside the container 10.

  The magnetic stirring blade 22 includes a substantially disc-shaped rotating base portion 22a that is rotated by the magnetic force of the magnetic stirrer 24, and a stirring blade portion 22b that is erected on the rotating base portion 22a so as to have a substantially cross shape. In this embodiment, the rotation base 22a is formed from stainless steel, and the stirring blade 22b is formed from anodized aluminum or the like, but is not limited thereto, and can be formed from various materials. is there. In addition, since various well-known blade | wing type stirring elements can be employ | adopted for the magnetic stirring blade 22, the detailed description is abbreviate | omitted.

  The magnetic stirrer 24 includes a housing 24a on which the container 10 is placed, a rotating magnet unit 24b disposed inside the housing 24a, a drive source 24c such as a motor that rotates the rotating magnet unit 24b, and a drive. A rotation control unit (not shown) for controlling the operation of the source 24c. The rotating magnet unit 24b includes a disk-shaped rotating disk configured to rotate by a driving source 24c and a magnet provided on the rotating disk. When the rotating magnet unit 24b is rotated by the driving source 24c, The rotating base 22a of the magnetic stirring blade 22 is rotated by the magnetic force. The rotation control unit is configured to be able to arbitrarily set the number of rotations of the rotating magnet unit 24b. The rotation source unit 24c is configured so that the rotating magnet unit 24b and the magnetic stirring blade 22 rotate at the set number of rotations. Control the behavior. The number of rotations of the rotating magnet part 24b can be arbitrarily set according to the target sizing accuracy of the particulate matter. Note that various known magnetic stirrers can be adopted as the magnetic stirrer 24, and thus detailed description thereof is omitted.

  The suction means 30 is composed of a pump or the like that sucks gas at a set predetermined flow rate, and the gas flow inside the storage container 10 is connected via a hose 32 connected to the outflow portion 18 of the lid 14 of the storage container 10. (Aerosol) and particulate matter in the gas flow are configured to be discharged to the outside of the container 10. Note that various known suction means can be adopted as the suction means 30, and detailed description thereof is omitted.

  The collection means 40 includes a sampling holder 42 that can be attached to the outflow portion 18 of the lid 14 of the storage container 10, and a filter (not shown) held by the sampling holder 42. As long as the filter can collect almost 100% of the particulate matter to be measured for the floating characteristics, various known filters can be adopted, and thus detailed description thereof is omitted.

  The arithmetic processing unit is composed of various arithmetic processing devices such as a personal computer, for example, and based on the collected amount of particulate matter (weighing value described later) input by the measurer and the flow rate at the time of collection. It is configured to calculate the concentration of the substance. In addition, the arithmetic processing unit is configured to calculate the floating coefficient of the particulate matter based on the calculated concentration of the particulate matter and the concentration of a reference sample (control material) described later.

  The floating characteristic measuring apparatus 1 having the above configuration generates a swirl flow inside the storage container 10 by the swirl flow generation means 20, thereby generating a gas flow (aerosol) containing particulate matter inside the storage container 10. While being generated, the particulate matter is classified in the container 10. Specifically, the floating property measuring apparatus 1 is configured to generate a gas flow containing particulate matter to be measured inside the storage container 10 and to make the swirl flow F. In addition, the floating characteristic measuring apparatus 1 uses the centrifugal force of the swirling flow F so that the particles 4a and 4b having a large mass are radiated in the radial direction of the container 10 as shown in FIGS. 2 (a) and 2 (b). The particles 4c having a small mass are moved outward and downward, and the particles 4c having a small mass are moved inward and upward in the radial direction of the container 10 so that particles having different sizes are divided. Such a cyclonic sizing principle is well known, and a detailed description thereof will be omitted. In FIGS. 2A and 2B, the size of the particulate matter (particles 4a, 4b, 4c) is exaggerated for easy understanding. Further, in FIGS. 2A and 2B, illustration of structures unnecessary for description is omitted.

  Next, a method for measuring floating characteristics (floating characteristic measuring method) that can be a risk evaluation index of particulate matter using the floating characteristic measuring apparatus 1 according to the present embodiment will be described.

  As shown in FIG. 3, the method for measuring floating characteristics according to the present embodiment schematically includes a gas flow generation step (S1) for generating a gas flow including particulate matter to be measured, and a measurement target. A sizing step (S2) for sizing the particulate matter based on its size, and a collecting step (S3) for collecting only the particulate matter having a small mass from the sized particulate matter And a concentration measurement step (S4) for measuring the concentration of the collected particulate matter, and comparing the concentration measured in the concentration measurement step with the concentration of the reference reference material, thereby measuring the particulate matter to be measured And a floating coefficient measuring step (S5) for measuring the floating coefficient of the substance. Hereinafter, these steps will be described in detail.

  First, in the gas flow generation step (S1), in a state where the container body 12 is sealed by the lid body 14, the particulate matter to be measured is caused to flow into the storage container 10 through the inflow portion 16 and swirl. A swirling flow is generated inside the container 10 by the flow generating means 20. As a result, a gas flow (aerosol) containing the particulate matter to be measured is generated inside the container 10. Next, in the sizing step (S2), the generation of the swirling flow is continued for a predetermined time, whereby the particles 4a and 4b having a large mass are moved radially outward and downward by the centrifugal force of the swirling flow. Then, the particles 4c having a small mass are moved inward and upward in the radial direction of the storage container 10 to thereby classify particles having different sizes (see FIGS. 2A and 2B).

  This sizing step is a step performed to collect (collect) particulate matter having a size that may cause harm to the living body. That is, the particulate substances (fine powder) generally marketed as raw materials and experimental materials for various products are not necessarily all in the form of fine particles. Nano size), fine particles (micron size), and particles of several hundred microns are mixed. In order to evaluate the harmfulness of such particulate matter to the living body, particles having a size that is unlikely to cause harm to the living body are removed, and particles having a size that is likely to cause harm to the living body (for example, extreme poles). Since it is necessary to collect only the fine particles), the sizing process is performed in the floating characteristic measurement method according to the present embodiment.

  Next, in the collecting step (S3), the suction means 30 sucks from the outflow portion 18 formed in the radial center portion and the upper portion of the storage container 10, thereby allowing the gas in the central portion of the swirl flow and Particulate matter is caused to flow out of the container 10, and the particulate matter that has flowed out is collected by the collecting means 40. Thereby, it is possible to collect only particles (for example, ultrafine particles) having a size that may cause harm to the living body. Note that the gas flow generation step (S1), the sizing step (S2), and the collection step (S3) are executed using the floating characteristic measuring apparatus 1.

Next, in the concentration measurement step (S4), based on the amount of air sucked by the suction means 30 and the change in the weight of the filter before and after collection (weighing value), the collection point (that is, the central portion of the swirl flow) ) To calculate the concentration of particulate matter. Specifically, the sucked air amount [L] is the product of the flow rate during collection (collection flow rate) [L / min] and the collection time [min] (“collection flow rate” × “collection”). Time)). The weighed value [mg] is calculated from the difference between the filter weight before collection and the filter weight after collection (“filter weight after collection” − “filter weight before collection”). Furthermore, the concentration [mg / m ³ ] of the particulate matter at the collection point is the quotient of the weighed value [mg] and the sucked air amount [L] (“weighed value” ÷ (“air amount” ÷ 1000) ). The calculation of the concentration of the particulate matter is performed using an arithmetic processing unit such as a personal computer. Further, the input of the air amount [L] and the weighing value [mg] to the arithmetic processing unit may be automatically inputted through the suction means 30 or the weighing measuring means (not shown) or the like, or by the measurer. It may be input manually.

  In the floating coefficient measurement step (S5), the concentration of the particulate matter to be measured calculated in the concentration measurement step (S4) and the concentration of the reference material calculated in the same step as the concentration measurement step (S4) described above. Based on the above, the floating coefficient of the particulate matter to be measured is calculated. Specifically, the floating coefficient is the quotient of the concentration of the particulate matter to be measured and the concentration of the reference reference material (“particulate matter concentration to be measured” ÷ “concentration of the reference material”) Is calculated by Here, the reference control substance is (1) easy to obtain, (2) from its particle size, it has a high possibility of reaching the lungs when aspirated (highly harmful to the living body), (3) It is preferable to select on the condition that it has substantially standard floating characteristics (it is appropriate that the floating coefficient is 1). In view of these conditions, for example, it is easy to obtain and is harmful to living organisms, and the empirical rule for floating is that the floating coefficient is roughly equivalent to an intermediate value (standard floating) However, the present invention is not limited to this. The calculation of the floating coefficient is performed using an arithmetic processing unit such as a personal computer. The concentration of the control substance is measured before the measurement of the particulate matter to be measured, and the control substance concentration stored in the calculation processing unit may be used, or manually input by the measurer. It may be a set value.

  And when calculating a floating coefficient also about other particulate matter, the above-mentioned gas flow generation process (S1), sizing process (S2), collection process (S3), concentration measurement process (S4), and floating These steps are executed under the same conditions as in the coefficient measurement step (S5). Thereby, since it becomes possible to obtain the floating coefficient with respect to a common reference | standard (control substance) about various particulate matters, it becomes possible to compare the harmfulness with respect to a biological body mutually.

  As described above, the floating characteristic measurement method according to the present embodiment includes the gas flow generation step (S1) for generating a gas flow containing the particulate matter to be measured, and the collection of the particulate matter from the gas flow. The collecting step (S3), the concentration measuring step (S4) for measuring the concentration of the particulate matter collected by the collecting step, and the concentration measured by the concentration measuring step as the reference concentration of the reference material And a floating coefficient measuring step (S5) for measuring the floating coefficient of the particulate matter.

  According to such a floating characteristic measurement method, it is possible to indicate the floating characteristic of the particulate matter to be measured by a quantitative value called a floating coefficient. And since this floating coefficient quantitatively shows the floating characteristics of the particulate matter, it should be used as a judgment standard for harmfulness to the living body (the level of floating and entering the living body). It can be used as a risk assessment index for substances. As a result, for example, to purchasers and users who purchase particulate materials to use as raw materials or experimental materials for various products, the particulate materials are given to the living body by a quantitative value called a floating coefficient. It is possible to recognize the impact.

  In addition, as described above, the method for measuring floating characteristics according to the present embodiment is a sizing step (S2) for sizing ultrafine particles by using a gas flow (aerosol) as a swirl flow before the collection step (S3). ). According to such a method for measuring floating characteristics, particles having a size that is unlikely to cause harm to the living body are removed, and only particles having a size that is likely to cause harm to the living body are collected to calculate the floating coefficient. Therefore, it is possible to provide a more reliable risk evaluation index.

  Furthermore, as described above, the floating characteristic measuring apparatus 1 according to the present embodiment has the magnetic stirring blade 22 disposed inside the sealed container (container 10) disposed outside the sealed container (container 10). The magnetic stirrer 24 is rotated by the magnetic force. According to such a floating characteristic measuring apparatus 1, a shaft for connecting the stirring blade and the motor is not necessary, and it is not necessary to form a through hole for penetrating the shaft in the storage container. It becomes possible to prevent leakage of particulate matter.

  The preferred embodiment of the present invention has been described above, but the technical scope of the present invention is not limited to the scope described in the above-described embodiment. Various modifications or improvements can be added to the above embodiments.

  For example, in the floating characteristic measurement method according to the above-described embodiment, it has been described that the sizing process (S2) for sizing the ultrafine particles by the swirling flow is performed before the collecting process (S3). It is not limited, You may perform a collection process (S3), without performing a sizing process. In addition, the sizing step (S2) is not limited to a method (cyclonic method) in which the particulate material is subjected to centrifugal force to perform the sizing, and for example, the particulate material collides with an obstacle arranged in the airflow. It is possible to adopt various sizing methods such as a sizing method and a sizing method by applying electrostatic force or gravity to the particulate matter. In this case, it is possible to employ various known sizing means suitable for the sizing method employed in the floating characteristic measuring apparatus 1.

  Moreover, in the floating characteristic measuring method according to the above-described embodiment, the concentration of the particulate matter is calculated based on the amount of air sucked by the suction unit 30 and the change (weight value) of the filter weight before and after the collection. Although described as a thing, it is not limited to this, For example, it is possible to employ | adopt various methods, such as a scattered light type | mold density | concentration measuring method which measures a density | concentration based on the scattered light produced by the particulate matter. In this case, it is possible to employ various known means adapted to the employed concentration measuring method in the floating characteristic measuring apparatus 1 or to attach the means to the floating characteristic measuring apparatus 1 together.

  Further, the floating property measuring apparatus 1 according to the present embodiment is preferably used as various devices that generate aerosol and classify and collect particulate matter in addition to the above-described method for measuring the floating property. Is possible. For example, according to the floating property measuring apparatus 1 according to the present embodiment, since minute substances such as many types of multi-walled carbon nanotubes (MWCNT) can be separated and collected from the air, the working environment of these minute substances It can also be used for measurement and personal exposure measurement.

  It is clear from the description of the scope of claims that the above modifications are included in the scope of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these Examples.

[Example 1]
A powdery antimony trioxide (Sb ₂ O ₃ ) raw material sample A and samples (BD) obtained by subjecting the raw material sample A to surface treatment are prepared, and the floating characteristic measuring apparatus 1 is used for each sample. The aerosol was generated, sized and collected, and the buoyancy coefficient was calculated by comparison with the control substance (carbon black). In addition, an antimony trioxide (Sb ₂ O ₃ ) raw material sample E different from the raw material sample A and a sample (F to H) subjected to surface treatment on this raw material sample E are prepared. Then, aerosol generation, sizing, and collection were performed using the floating characteristic measuring apparatus 1, and the floating coefficient was calculated in comparison with the control substance (carbon black). The degree of surface treatment is sample B <C <D and sample F <G <H, respectively. The measurement procedure and conditions are as follows. The container body 12 was a stainless steel container having a diameter of 25 cm, a height of 25 cm, and a volume of about 10 L. Further, a 37 mmφ fluororesin-treated glass fiber filter T60A20 (manufactured by Tokyo Direc Co., Ltd.) was used for the filter of the collecting means 40.

First, the weight of the filter of the collecting means 40 was weighed and set in the sampling holder 42. Next, the magnetic stirring blade 22 (φ90 mm, 35 Hmm) was rotated at 1400 rpm by the magnetic stirrer 24, and then 0.5 g of the sample A was put into the storage container 10. Next, the suction means 30 sucked at a suction flow rate of 2.75 mL / min for 30 minutes. After completion of sampling, the filter was taken out from the sampling holder 42 and its weight was weighed with a microbalance. Based on the suction flow rate, the suction time (collection time), and the difference in weight of the filter before and after collection (weighing value), ““ collection point concentration [mg / m ³ ] ”=“ weighing value [ mg] ”÷ (“ collection flow rate [L / min] ”ד collection time [min] ”÷ 1000)” was used to calculate the concentration of sample A at the collection point (the center of the swirl flow). . Finally, the calculated concentration of sample A and carbon black (12 types of JIS test powder 1, particle size distribution 0.03 to 0.20 μm, measured by the same procedure in advance, Japan Powder Industry Technology) The float coefficient of sample A was calculated based on the following formula: “Floating coefficient” = “Concentration of sample (particulate matter to be measured)” ÷ “Control substance concentration” . In addition, the floating coefficient was calculated for each of Samples B to H by the same procedure.

  The measurement results of the samples A to D according to the above procedure are shown in FIGS. 4 and 5 together with the measurement result of the carbon black (control substance), and the measurement results of the samples A to D are also shown together with the measurement result of the carbon black (control substance). 6 and FIG. The input amount [mg] of the sample was measured to the first decimal place, the weighed value [mg] was measured to the third decimal place, and the floating coefficient was calculated to the fourth decimal place. As apparent from FIGS. 4 to 7, the buoyancy coefficients of the samples are as follows: original sample A: 0.0779, sample B: 0.0058, sample C: 0.0007, sample D: 0.0080, original Sample E: 4.7320, Sample F: 0.8456, Sample G: 0.4916, Sample H: 0.2265. From this result, it became clear that the original sample A has the characteristic that it is most likely to float among the samples A to D (floating characteristics), and all of the samples B to D have extremely low floating characteristics. In addition, among samples E to H, the original sample E has the characteristic that it is most likely to float (floating characteristic), and subsequently has the characteristic that it is likely to float in the order of sample F → sample G → sample H. It became clear. Among the samples A to D, the original sample A has the largest floating coefficient, and the samples E to H have the largest floating coefficient of the original sample E. It is presumed that the degree of floatation is large because of the original sample that has not been subjected to the treatment, and the degree of suspension was suppressed by applying the surface treatment to the other samples B to D and F to H.

[Example 2]
Seven kinds of powdered nano titanium oxide (TiO ₂ ) (samples A ′ to G ′) are prepared, and aerosol generation, sizing and collection are performed for each sample using the floating characteristic measuring apparatus 1, and a control substance (carbon The floating coefficient was calculated in comparison with (Black). The measurement procedure and conditions are the same as in Example 1 except that a glass container (volume: 10 L) is used as the container body 12 and that the amount of sample introduced into the storage container 10 is 0.1 g. Therefore, the description is omitted.

  As a result of the measurement, the floating coefficients of the samples are as follows: Sample A ′: 0.04, Sample B ′: 2.01, Sample C ′: 2.68, Sample D ′: 4.26, Sample E ′: 14. 08, sample F ′: 21.94, and sample G ′: 61.61. The floating coefficient was calculated to the second decimal place. From this result, the sample G ′ has the characteristic that it is most likely to float (floating property), and then in the order of the sample F ′ → the sample E ′ → the sample D ′ → the sample C ′ → the sample B ′ → the sample A ′. It became clear that it has the characteristic that it is easy to float. The reason why the floating coefficient of the sample G ′ is large is presumed that there is a gap between the primary particles from the result of SEM observation. The reason why the floating coefficient of the sample A ′ is small is presumed that the secondary particles are dense from the result of SEM observation.

  DESCRIPTION OF SYMBOLS 1 Floating characteristic measuring apparatus, 10 container, 20 swirl flow production | generation means, 22 magnet type stirring blade, 24 magnetic stirrer, 30 suction means, 40 collection means

Claims (5)

A gas flow generating step for generating a gas flow containing particulate matter to be measured;
A collection step of collecting the particulate matter from the gas stream;
A concentration measuring step for measuring the concentration of the particulate matter collected by the collecting step;
A suspension coefficient measuring step of measuring a suspension coefficient of the particulate matter by comparing the concentration measured by the concentration measurement step with a concentration of a reference control substance serving as a reference. Method for measuring floating characteristics. Before the collection step, further comprising a sizing step of sizing ultrafine particles by turning the gas flow into a swirling flow,
The method for measuring the floating characteristics of a particulate matter according to claim 1, wherein the collecting step is a step of collecting the ultrafine particles sized by the sizing step as the particulate matter. A floating characteristic measuring apparatus used in the method for measuring the floating characteristic of particulate matter according to claim 1 or 2,
A storage container capable of storing the particulate matter;
A swirl flow generating means capable of generating a swirl flow in the container;
A suction means provided at an upper part of the container, and capable of sucking the gas at the center of the swirl flow and the particulate matter in the gas;
And a collection means capable of collecting the particulate matter sucked by the suction means. The floating characteristics measuring device according to claim 3, wherein the container is configured so that the inside thereof can be visually recognized from the outside. The swirl flow generating means includes
A magnetic stirring blade disposed inside the storage container;
5. The floating characteristic measuring device according to claim 3, further comprising: a magnetic stirrer arranged outside the storage container and capable of rotating the magnetic stirring blade by a magnetic force.

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