JPH0230658B2 - FUNTAIHI HYOMENSEKIKEISOKUTEISOCHI - Google Patents
FUNTAIHI HYOMENSEKIKEISOKUTEISOCHIInfo
- Publication number
- JPH0230658B2 JPH0230658B2 JP22249782A JP22249782A JPH0230658B2 JP H0230658 B2 JPH0230658 B2 JP H0230658B2 JP 22249782 A JP22249782 A JP 22249782A JP 22249782 A JP22249782 A JP 22249782A JP H0230658 B2 JPH0230658 B2 JP H0230658B2
- Authority
- JP
- Japan
- Prior art keywords
- sample
- sample powder
- powder layer
- air
- specific surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000843 powder Substances 0.000 claims description 35
- 239000002245 particle Substances 0.000 description 7
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000000945 filler Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/088—Investigating volume, surface area, size or distribution of pores; Porosimetry
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Arrangements Characterized By The Use Of Fluids (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Description
本発明は粉体の比表面積径を測定する装置に関
し、更に詳しくは、空気透過法を用いた比表面積
径測定装置に関する。
一般に、この種方法を用いた測定装置において
は、試料セル内に試料粉体を圧縮充填して試料粉
体層を形成し、その粉体層の両端に所定の差圧△
Ｐを与えて空気を透過せしめ、そのときの粉体層
の厚さＬと透過空気の流量Ｑ／ｔ（透過体積Ｑと
その所要時間ｔ）を計測して、まず下記の(1)式に
示すコゼニー・カーマン式を用いて試料粉体の比
表面積Swを求める。
ここで
ε；試料粉体の空隙率
（ε＝１−Ｗ／ρP・Ａ・Ｌ (2)）
ρP；試料粉体の密度
Ａ；粉体層の断面積
η；透過空気の粘性係数
Ｗ；試料粉体重量
次に、試料粉体が球形又は立方体の均一な粒子
から成つていると仮定したとき、粉体の比表面積
Swと比表面積径Dmとの関係が次の(3)式で表わ
され、
Sw＝６／ρP・Dm ………(3)
この(3)式と上述の(1)式によつて比表面積径Dm
を下記に示す(4)式から算出する。
ここで
The present invention relates to an apparatus for measuring the specific surface area diameter of powder, and more particularly to an apparatus for measuring the specific surface area diameter using an air permeation method. Generally, in a measuring device using this type of method, sample powder is compressed and packed into a sample cell to form a sample powder layer, and a predetermined differential pressure △ is applied between both ends of the powder layer.
P is given to allow air to permeate, and the thickness L of the powder layer and the flow rate Q/t of the permeated air (the permeation volume Q and the required time t) are measured, and first, the following formula (1) is calculated. Determine the specific surface area Sw of the sample powder using the Kozeny-Karman equation shown below. Here, ε: Porosity of sample powder (ε=1-W/ρ P・A・L (2)) ρ P : Density A of sample powder; Cross-sectional area η of powder layer; Viscosity coefficient of permeated air W: Sample powder weight Next, assuming that the sample powder consists of spherical or cubic uniform particles, the specific surface area of the powder is
The relationship between Sw and specific surface area diameter Dm is expressed by the following equation (3), Sw = 6/ρ P・Dm ...... (3) From this equation (3) and the above equation (1), Specific surface area diameter Dm
is calculated from equation (4) shown below. here
【式】
ｆ(L)＝Ｌ・（１−ε）2／ε3 ………(5)
このようにして求められる比表面積径Dmは、
外部比表面積に基づく試料粉体の平均粒子径を表
わしている。そして、このような空気透過法によ
る比表面積径の測定は、約１〜100μｍの粒径範
囲にある粉体の測定に適しており、通常上述の如
き粒径範囲にある粉体の平均的な粒子径の測定に
は、主としてこの種の測定装置が用いられてい
る。
従来のこの種測定装置においては、試料層両端
に与える差圧△Ｐの値を、試料の相違等に拘わら
ず一定の値として制御していた。ここで、この種
従来装置によつて測定されるべき粉体の粒径範囲
が上述の如き広範囲にわたる為、試料の相違によ
つて圧縮充填後の試料層厚さＬや(2)式によつて算
出される試料粉体の空隙率εの値が広い範囲で変
化し、その為流量Ｑ／ｔも試料の相違に起因して
大きく変化する。従つて上述の如き従来装置によ
れば、流量Ｑ／ｔを広い範囲にわたつて精度よく
測定しなければ比表面積径Dmの算出値に誤差を
生ずるという問題点を有し、広範囲にわたる流量
の高精度測定は極めて困難であるのが実状であ
る。
本発明は上記の技術的課題を解消すべくなされ
たもので、狭い範囲で流量Ｑ／ｔを高精度に測定
しさえすれば、比表面積径Dmの算出値に誤差を
生じない高精度の粉体比表面積径測定装置の提供
を目的とする。
本発明の特徴とするところは、(5)式で求められ
る試料層厚さＬの関数ｆ(L)との比ｆ(L)／△Ｐがあ
らかじめ設定された一定値となるような△Ｐを算
出し、試料層両端に与えるべき差圧がその算出値
△Ｐとなるように制御するよう構成したことにあ
る。
以下、図面に基づいて本発明実施例を説明す
る。
図面は本発明実施例の構成図である。
試料セル１内に投入された試料粉体Ｗは、両端
に配されたふるい板２，２を介して充填器３によ
つて圧縮充填される。圧縮充填後の試料層厚さＬ
は、厚さ測定器４によつて充填器３の圧縮ストロ
ーク等を検出することによつて測定される。その
出力はｆ(L)演算器５に導入され、ｆ(L)演算器５で
は上述の(5)式にＬを代入してｆ(L)に変換し、その
出力を△Ｐ設定器６に供給する。△Ｐ設定器６で
は、あらかじめプログラムされた下記の(6)式を満
足するような△Ｐの信号を発生してサーボアンプ
７に供給する。
ｆ(L)／△Ｐ＝α、α＝const. ………(6)
サーボアンプ７はその△Ｐ信号を目標値として
サーボモータ８を回動させ、駆動機構９を介して
シリンダ１０のピストンを摺動せしめて空気を吐
出させる。このとき試料層両端に生ずる差圧を差
圧計１１で検出し、その検出値をサーボアンプ７
に負帰還して、試料層Ｗ両端の差圧が目標値△Ｐ
となるようなフイードバツクループを形成してい
る。よつて試料層Ｗは、△Ｐ設定器によつて設定
された△Ｐなる両端差圧のもとに、空気が透過さ
れる。その透過した空気は流量計１２により流量
Ｑ／ｔが測定され、その値は演算回路１３に供給
される。一方、透過空気の温度は温度計１４によ
つて測定され、空気の粘性係数η情報として演算
回路１３に供給される。また、演算回路１３には
定数項発生器１５が接続され、定数項発生器１５
は(4)式中の定数Ｋに応じた信号を発生して演算回
路１３に供給する。演算回路１３においては、流
量計１２からのＱ／ｔ、定数項発生器１５からの
Ｋ、温度計１４からの透過空気温度に基づく空気
の粘性係数η、および(6)式における定数α（＝ｆ
(L)／△Ｐ）を用いて、(4)式を演算して試料粉体の
比表面積径Dmを算出し、その値を表示器１６に
表示させるよう構成されている。
以上のような本発明実施例によれば、試料粉体
Ｗを試料セル１内に投入して充填器３によつて圧
縮充填すると同時に、試料厚さＬが測定され、直
ちに(6)式に基づいて試料層両端に与えられるべき
差圧△Ｐが設定される。従つて、試料層の厚さＬ
または空隙率εに応じて適度の差圧△Ｐが与えら
れるので、試料の相違にも拘わらず透過する空気
の流量Ｑ／ｔはある限定された範囲内におさま
る。
以上説明したように、本発明によれば、試料層
の厚さＬや空隙率εに応じた差圧△Ｐのもとに空
気が透過され、従つてその流量Ｑ／ｔは、従来装
置の如く一定差圧で透過される場合に比して変化
範囲は極めて狭くなり、流量計の測定範囲が狭く
なつて高精度化が容易となる。また流量範囲が狭
くなるため、サーボ機構の制御も行いやすい。更
に、ｆ(L)／△Ｐがあらかじめ設定された一定値で
ある為、(4)式による比表面積径Dmの演算が簡素
化される。[Formula] f(L)=L・(1−ε) 2 /ε 3 ………(5) The specific surface area diameter Dm obtained in this way is
It represents the average particle diameter of the sample powder based on the external specific surface area. Measurement of the specific surface area diameter by such an air permeation method is suitable for measuring powders in the particle size range of about 1 to 100 μm, and usually measures the average particle size of powders in the above particle size range. This type of measuring device is mainly used to measure particle diameters. In a conventional measuring device of this type, the value of the differential pressure ΔP applied to both ends of the sample layer was controlled to be a constant value regardless of the difference in the sample. Here, since the particle size range of the powder to be measured by this type of conventional device is wide as described above, the sample layer thickness L after compression filling and the equation (2) may vary depending on the sample. The value of the porosity ε of the sample powder thus calculated changes over a wide range, and therefore the flow rate Q/t also changes greatly due to the difference in the sample. Therefore, the conventional device as described above has the problem that unless the flow rate Q/t is accurately measured over a wide range, an error will occur in the calculated value of the specific surface area diameter Dm. The reality is that accuracy measurement is extremely difficult. The present invention has been made to solve the above technical problem, and is a highly accurate powder that does not cause any error in the calculated value of the specific surface area diameter Dm as long as the flow rate Q/t is measured with high precision in a narrow range. The purpose of this invention is to provide a body specific surface area diameter measuring device. The feature of the present invention is that the ratio f(L)/△P of the sample layer thickness L to the function f(L) obtained by equation (5) is a constant value set in advance. is calculated and controlled so that the differential pressure to be applied to both ends of the sample layer becomes the calculated value ΔP. Embodiments of the present invention will be described below based on the drawings. The drawings are configuration diagrams of embodiments of the present invention. The sample powder W introduced into the sample cell 1 is compressed and filled by a filler 3 through sieve plates 2, 2 arranged at both ends. Sample layer thickness L after compression filling
is measured by detecting the compression stroke of the filling device 3 using the thickness measuring device 4. The output is introduced into the f(L) calculator 5, which converts it into f(L) by substituting L into the above equation (5), and converts the output into the △P setter 6. supply to. The ΔP setting device 6 generates a ΔP signal that satisfies the preprogrammed equation (6) below and supplies it to the servo amplifier 7. f(L)/△P=α, α=const. (6) The servo amplifier 7 rotates the servo motor 8 using the △P signal as a target value, and drives the piston of the cylinder 10 via the drive mechanism 9. Slide and close to discharge air. At this time, the differential pressure generated between both ends of the sample layer is detected by the differential pressure gauge 11, and the detected value is sent to the servo amplifier 7.
negative feedback, the differential pressure across both ends of the sample layer W reaches the target value △P
A feedback loop is formed. Therefore, air is permeated through the sample layer W under the pressure difference between both ends ΔP set by the ΔP setting device. The flow rate Q/t of the permeated air is measured by a flow meter 12, and the value is supplied to an arithmetic circuit 13. On the other hand, the temperature of the permeated air is measured by the thermometer 14 and is supplied to the arithmetic circuit 13 as information on the viscosity coefficient η of the air. Further, a constant term generator 15 is connected to the arithmetic circuit 13.
generates a signal corresponding to the constant K in equation (4) and supplies it to the arithmetic circuit 13. In the arithmetic circuit 13, Q/t from the flow meter 12, K from the constant term generator 15, air viscosity coefficient η based on the permeated air temperature from the thermometer 14, and constant α (= f
(L)/ΔP), calculates the specific surface area diameter Dm of the sample powder by calculating equation (4), and displays the value on the display 16. According to the embodiment of the present invention as described above, at the same time as the sample powder W is put into the sample cell 1 and compressed and filled by the filling device 3, the sample thickness L is measured and immediately calculated using equation (6). Based on this, the differential pressure ΔP to be applied to both ends of the sample layer is set. Therefore, the thickness L of the sample layer
Alternatively, since an appropriate differential pressure ΔP is provided according to the porosity ε, the flow rate Q/t of the permeating air is within a certain limited range regardless of the difference between the samples. As explained above, according to the present invention, air is permeated under the differential pressure ΔP depending on the thickness L and porosity ε of the sample layer, and therefore the flow rate Q/t is lower than that of the conventional device. Compared to the case where the fluid is permeated at a constant pressure difference, the range of change is extremely narrow, and the measurement range of the flowmeter is narrowed, making it easier to achieve high accuracy. Furthermore, since the flow rate range is narrowed, it is easier to control the servo mechanism. Furthermore, since f(L)/ΔP is a constant value set in advance, calculation of the specific surface area diameter Dm using equation (4) is simplified.
図面は本発明実施例の構成図である。
１……試料セル、４……厚さ測定器、５……ｆ
(L)演算器、６……△Ｐ設定器、７……サーボアン
プ、８……サーボモータ、１０……シリンダ、１
１……差圧計、１２……流量計、１３……演算回
路、１４……温度計、１５……定数項発生器、１
６……表示器。
The drawings are configuration diagrams of embodiments of the present invention. 1...sample cell, 4...thickness measuring device, 5...f
(L) Arithmetic unit, 6...△P setting device, 7... Servo amplifier, 8... Servo motor, 10... Cylinder, 1
1...Differential pressure gauge, 12...Flowmeter, 13...Arithmetic circuit, 14...Thermometer, 15...Constant term generator, 1
6...Indicator.
Claims (1)
端に、所定の差圧△Ｐを与えて空気を透過せし
め、その透過空気の流量Ｑ／ｔと圧縮充填された
試料粉体層厚さＬを計測し、コゼニー・カーマン
式から導出される下記の式に基づいて試料粉体の
比表面積径Dmを求める装置において、上記差圧
△Ｐと下記の式中の試料粉体層厚さＬの関数ｆ(L)
との比ｆ(L)／△Ｐがあらかじめ設定された一定値
となるような△Ｐを算出する手段と、その算出値
△Ｐを目標値として試料粉体層両端の差圧を制御
する手段を備えたことを特徴とする粉体比表面積
径測定装置。 ここで【式】ｆ(L)＝Ｌ・（１−ε）2／ε3 −ε＝１Ｗ／ρP・Ａ・Ｌ また、 Dm；粉体の比表面積径 △Ｐ；試料粉体層両端の圧力差 Ｑ；試料粉体層透過空気量 ｔ；Ｑなる空気が試料粉体層を透過するに要した
時間 η；透過空気の粘性係数 Ｌ；試料粉体層厚さ Ａ；試料粉体層の断面積 ρP；試料粉体の密度 Ｗ；試料粉体重量[Claims] 1. A predetermined differential pressure ΔP is applied to both ends of a sample powder layer compressed and filled in a sample cell to allow air to pass through, and the flow rate Q/t of the permeated air is equal to In an apparatus that measures the sample powder layer thickness L and determines the specific surface area diameter Dm of the sample powder based on the following formula derived from the Kozeny-Kurman equation, the above differential pressure △P and the sample in the following formula are used. Function f(L) of powder layer thickness L
Means for calculating △P such that the ratio f(L)/△P becomes a preset constant value, and means for controlling the differential pressure between both ends of the sample powder bed using the calculated value △P as a target value. A powder specific surface area diameter measuring device characterized by comprising: Here, [Formula] f(L)=L・(1−ε) 2 /ε 3 −ε=1W/ρ P・A・L Also, Dm: Specific surface area diameter of the powder △P: Both ends of the sample powder layer pressure difference Q; amount of air passing through the sample powder layer t; time η required for air Q to pass through the sample powder layer; viscosity coefficient L of permeating air; thickness A of the sample powder layer; sample powder layer Cross-sectional area ρ P ; Density W of sample powder; Weight of sample powder
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22249782A JPH0230658B2 (en) | 1982-12-17 | 1982-12-17 | FUNTAIHI HYOMENSEKIKEISOKUTEISOCHI |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22249782A JPH0230658B2 (en) | 1982-12-17 | 1982-12-17 | FUNTAIHI HYOMENSEKIKEISOKUTEISOCHI |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59170745A JPS59170745A (en) | 1984-09-27 |
| JPH0230658B2 true JPH0230658B2 (en) | 1990-07-09 |
Family
ID=16783351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22249782A Expired - Lifetime JPH0230658B2 (en) | 1982-12-17 | 1982-12-17 | FUNTAIHI HYOMENSEKIKEISOKUTEISOCHI |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0230658B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0840104A4 (en) * | 1995-01-12 | 1999-02-10 | Vladimir Nikolaevich Belonenko | Devices for measuring viscosity and for investigating fluid flow through capillary-porous mediums |
| US6460420B1 (en) * | 2000-04-13 | 2002-10-08 | Sandia National Laboratories | Flowmeter for pressure-driven chromatography systems |
| FR2840071B1 (en) * | 2002-05-22 | 2004-07-23 | Saint Gobain Isover | DEVICE FOR DETERMINING THE FINESSE OF MINERAL FIBERS |
| JP4827190B2 (en) * | 2004-08-12 | 2011-11-30 | ハルツォク・ジャパン株式会社 | Sample forming device for measuring specific surface area of powder |
| CN104677766A (en) * | 2014-09-30 | 2015-06-03 | 北京城市排水集团有限责任公司 | Method for detecting volcanic biological filter material |
| CN107525751B (en) * | 2017-08-24 | 2020-04-28 | 山东泰景电力科技有限公司 | Method and device for detecting wind-powder ratio and flow velocity by ultraviolet light source method |
| CN110261278A (en) * | 2019-07-11 | 2019-09-20 | 宁波石墨烯创新中心有限公司 | A method of measurement grapheme material powder specific-surface area detection |
-
1982
- 1982-12-17 JP JP22249782A patent/JPH0230658B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59170745A (en) | 1984-09-27 |
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