2019-11-05
使(shi)用Granutools粉體流動(dong)性分析儀進行乳糖粉體分析
介紹
理論概況
Granular materials and fine powders are widely used in industrial applications. To control and to optimize processing methods, these materials have to be precisely characterized. The characterization methods are related either to the properties of the grains (granulometry, morphology, chemical composition, …) and to the behaviour of the bulk powder (flowability, density, blend stability, electrostatic properties, …). However, concerning the physical behaviour of bulk powder, most of the techniques used in R&D or quality control laboratories are based on old measurement techniques. During the last decade, we have updated these techniques to meet the present requirements of R&D laboratories and production departments. In particular, the measurement processes have been automatized and rigorous initialization methods have been developed to obtain reproducible and interpretable results. Moreover, the use of image analysis techniques improves the measurements precision.
顆粒(li)狀材料(liao)和(he)精細粉體在工(gong)業上有著廣(guang)泛(fan)的(de)應用(yong)。為了控制(zhi)和(he)優化加工(gong)方(fang)(fang)法(fa)，必須對這些(xie)材料(liao)進行的(de)表(biao)征。表(biao)征方(fang)(fang)法(fa)既與顆粒(li)的(de)性(xing)質(粒度、形態、化學成分等)有關，也(ye)與粉體的行為(流動性(xing)、密度、共混穩定(ding)性(xing)、靜電性(xing)能等)有關。然(ran)而，關于散裝粉(fen)末的(de)(de)(de)物理(li)性能(neng)，大多(duo)數在研(yan)發(fa)或質量控制(zhi)實驗室使用的(de)(de)(de)技(ji)(ji)術是(shi)基于舊(jiu)的(de)(de)(de)測量技(ji)(ji)術。在過去(qu)的(de)(de)(de)十年(nian)中，我們更新(xin)了這(zhe)些技(ji)(ji)術，以(yi)滿足研(yan)發(fa)實驗室和(he)生產(chan)部門(men)目前的(de)(de)(de)要求。特別(bie)是(shi)，測量過程已經自動化，并開發(fa)了嚴格(ge)的(de)(de)(de)初(chu)始化方法，以(yi)獲得(de)可重(zhong)復和(he)可解釋的(de)(de)(de)結(jie)果。利用圖像分析技(ji)(ji)術提高了測量精(jing)度。
A range of measurement methods has been developed to cover all the needs of industries processing powders and granular materials. However, in this application note, we will be focused on the GranuFlow instrument.
一系列的測量方法已經得到發(fa)展，以涵蓋所有的需要，工業(ye)加(jia)工粉末和顆(ke)粒材料。但是，在這個(ge)應用中，我們將主要關(guan)注GranuFlow儀器。
粉體流動性分析儀
GranuFlow is an improved laboratory silo compared to the ancient Hall Flow Meter (ASTM B213, ISO4490) and compared to the “Flow Through An Orifice” method described in the Pharmacopea (USP1174).
與古老的霍爾流量計(ASTM B213, ISO4490) 或者與藥典(USP1174)中描述的“通過孔口的流動”方法相比，GranuFlow是一個先進的流速計。
GranuFlow is a straightforward powder flowability measurement device composed of a silo with different apertures associated with a dedicated electronic balance to measure the flowrate. This flowrate is computed automatically from the slope of the mass temporal evolution measured with the balance. The aperture size is modified quickly and easily with an original rotating system. The measurement and the result analysis are assisted by software. The flowrate is measured for a set of aperture sizes to obtain a flow curve. Finally, the whole flow curve is fitted with the well-known Beverloo theoretical model to obtain a flowability index (Cb, related to the powder flowability) and the minimum aperture size to obtain a flow (Dmin) (for theoretical background, user can refer to Appendix 1). The whole measurement is performed easily, fastly and precisely.
GranuFlow是一(yi)種簡單明了的(de)粉末流動性測量裝置，它由一(yi)個(ge)不(bu)同孔(kong)徑(jing)的(de)筒倉和一(yi)個(ge)專用(yong)(yong)的(de)電子天(tian)平組(zu)成(cheng)。這種流量是根據用(yong)(yong)天(tian)平測量的(de)流速(su)質量隨時間演化(hua)的(de)比率(lv)（斜率(lv)）自(zi)動計算(suan)出來(lai)的(de)。利用(yong)(yong)原有的(de)旋轉系統，可以快速(su)、方便(bian)地調整孔(kong)徑(jing)大(da)小。軟(ruan)件(jian)輔助測量和結果分(fen)析。通過測量一(yi)組(zu)孔(kong)徑(jing)尺寸來(lai)獲得流量曲線。后(hou),整個流動曲線是配(pei)備Beverloo理論模型獲得流(liu)動性指數(Cb、粉末流動性相關(guan))和小(xiao)(xiao)孔(kong)徑(jing)大小(xiao)(xiao)獲得流(Dmin)(為理論背景,用(yong)戶可以參考附(fu)錄1)。整個測量容易執行,快速準(zhun)確。
In this paper, we used a complete set of hole diameters: 4, 6, 8, 10, 12, 14 and 16mm.
在本(ben)文(wen)中，我們使用了一套(tao)完(wan)整的孔徑:4、6、8、10、12、14和16毫(hao)米。
The main purpose of this application note is to provide information regarding lactose analysis for the Pharmaceutical field.
本應用說明的主要目的是為醫(yi)藥(yao)領(ling)域提供(gong)有關乳糖分析的信息。
乳糖分析
材料
The powders used in this application are provided by Meggle Pharma. All these samples are made of lactose. They are called by the manufacturer Tablettose 70, Tablettose 80, Flowlac 90 and Flowlac 100. According to supplier’s data, the physico-chemical properties of these powders are described by the following table:
本應(ying)用中(zhong)使用的(de)粉(fen)(fen)末由Meggle Pharma提供(gong)。所有這些(xie)樣品都是乳糖。他們被制造商稱為Tablettose 70, Tablettose 80, Flowlac 90和Flowlac 100。根(gen)據供(gong)應(ying)商的(de)數據，這些(xie)粉(fen)(fen)末的(de)理(li)化性能描(miao)述(shu)如(ru)下表:
Table 1: Lactose physico-chemical properties
表1:乳糖理化性質
| 松裝密度(g/l) | 振實密度 | 豪斯納比 |
Tablettose 70 |
|
|
|
Tablettose 80 |
|
|
|
Flowlac 90 |
|
|
|
Flowlac 100 |
|
|
|
SEM pictures have been made in order to have an information of the particle size distribution and particles shape:
為了(le)獲得顆(ke)粒尺寸分布和顆(ke)粒形狀的信息(xi)，通(tong)過掃描電(dian)鏡獲得如下圖片(pian)：
The first observation concerns the particles shape, indeed, all Flowlac samples have spherical shape, while Tablettose samples have irregular one.
首先(xian)觀(guan)察到的(de)是顆粒的(de)形狀，所有(you)的(de)Flowlac樣品(pin)都是球形的，而(er)Tablettose樣品是不(bu)規則(ze)的。
Then, with the help of ImageJ Software, the granulometric analysis of the four samples have been carried out (dpp is the mean primary particle diameter and σ the standard deviation):
mageJ軟(ruan)件的幫助下,四個(ge)樣(yang)品進行(xing)了粒度分析(ddp是指初級粒子直徑和標準(zhun)差σ):
Table 2: Lactose granulometric analysis.
表(biao)2:乳糖(tang)顆(ke)粒分(fen)析。
使用GranuFlow進行分析(xi)
GranuFlow analysis were performed at 26°C and 40.0%RH (w = 8.5gH20/kgDryAir). Mass Flowrate was investigated for different hole size (from 4mm to 16mm). F is the powder flowrate (in g/s) and Cb the Beverloo parameter (in g/mm3). Dmin is the minimum aperture size to obtain a flow:
在26°C和(he)40.00% RH下(xia)(w = 8.5gH20/kg干燥空氣)進(jin)行(xing)顆粒(li)流分析。研究了不同孔徑(4mm ~ 16mm)下的質量流量。F為粉末(mo)流量(單(dan)位(wei)為g/s)， Cb為(wei)Beverloo參(can)數(單位為g/mm3)。Dmin是獲(huo)得(de)流量的小孔徑(jing)尺寸(cun):
Table 3: Raw data obtained with the GranuFlow instrument for the four lactose samples.
表(biao)3:通過GranuFlow儀(yi)器獲得的四個乳(ru)糖樣品的原始數據。
These results are really interesting, indeed by the look of Hausner ratio (cf. Table 1), we can see that the classical tap density test (“Densitap”) is unable to make differentiation between one sample to another (despite the high heterogeneity in terms of samples physico-chemical composition). However, GranuFlow allows to its user to make powder classification with great accuracy (with the help of Cb and Dmin parameters). Although Flowlac 90 and Tablettose70 have the same Cb parameter, Dmin information allows us to affirm that Flowlac90 has the best flowability from all samples and its followed by Tablettose70. Flowlac100 comes in third position, while Tablettose80 has the lower flowability. To prove these assumptions the following figure shows the mass flowrate according to hole diameter:
這些結果確實很有趣，從豪斯納比(bi)(cf. Table 1)可以看出，經典的振實密度測(ce)試(“Densitap”)無(wu)法區(qu)分(fen)樣品之間的差異(盡管樣品的物理化(hua)學成分具(ju)有(you)高度異質性)。然而，GranuFlow滿足用戶對粉(fen)末進行非常(chang)的分類(lei)(借助Cb和Dmin參數)。雖然(ran)Flowlac90和Tablettose70具有相(xiang)同的(de)Cb參數，但(dan)Dmin信息可以(yi)讓我們確認Flowlac90在所(suo)有樣本(ben)中流動性(xing)好，其次是Tablettose70。Flowlac100排在第三位，而Tablettose80的流動性較差。為了證明這些假設，下圖顯示(shi)了根(gen)據(ju)孔直徑的質量(liang)流量(liang):
Figure 5: Mass flowrate versus aperture size for all lactose samples. Lines represent the Beverloo law.
圖5:所有乳糖樣品的質量流量與孔(kong)徑大小。線條代表貝弗里(li)洛定律。
This graph shows the good correlation between experimental data and modeled values (with Beverloo law). This fact is highly important, because with the Beverloo model, user can make data interpolation, and thus predicts the mass flowrate for different hole sizes.
這(zhe)個圖表顯示了實驗數(shu)據(ju)和模型(xing)值之間的良(liang)好相關性(xing)(用貝(bei)弗里洛定律)。這(zhe)一事(shi)實是非常(chang)重要的(de)，因為在貝弗盧模型中(zhong)，用戶(hu)可以進行數據補充，從而預測不同(tong)孔大小的(de)質量(liang)(liang)流量(liang)(liang)。
Conclusions
總結
? GranuFlow allows to plot the full mass flowrate curve.
GranuFlow能夠繪(hui)制完(wan)整的質(zhi)量(liang)流量(liang)曲線
? GranuFlow gives information about the Beverloo law (i.e powder flowability and minimum diameter for the powder to flow in silo configuration).
GranuFlow給出了滿足(zu)貝弗里洛(luo)定律計算需要(yao)的(de)信息(xi)(如：在(zai)粉末(mo)在(zai)筒(tong)倉中，粉末(mo)的(de)流(liu)動性和小流(liu)出(chu)孔徑)
? GranuFlow allows to classify powders in terms of flowability, even if the classical tap density test is unable to see Hausner ratio difference.
即使經典的振(zhen)實(shi)密度測試無法看出(chu)豪斯納比值的差異，GranuFlow也能夠(gou)根據流動性對粉(fen)末進行(xing)分類。
Bibliography
參考文獻
Appendix 1: GranuFlow theoretical background
附錄(lu)1：GranuFlow理論背(bei)景
The mass flowrate F through a circular orifice of diameter D is given by the product of the mean speed of the grains <vout>, the aperture area and the bulk density ρ. One has the general expression:
質量流(liu)率F通過圓(yuan)孔的直徑(jing)D的產物顆粒的平(ping)均速度<流出速度>、孔徑(jing)面積和(he)體(ti)積密度ρ。一(yi)個是一(yi)般表達式:
?? = ?? < ???????? >
?? ??2 4
The Beverloo's law is based on two hypotheses:
貝(bei)弗里洛(luo)定(ding)律(lv)基于(yu)兩(liang)個(ge)假設:
• The flow is blocked when the orifice diameter is below a threshold Dmin.
當孔板直徑低于閾值(zhi)Dmin時，阻擋流動。
• The grains experience a free fall before passing through the orifice, i.e. ???????? = √2 ?? ?? ??. This relation comes from the idea that the jamming mechanism is due to the formation of a semispherical arch before the orifice. If this arch has a typical size proportional to the aperture, we obtain ?? = 0,5. To be more general, the parameter ?? can be a free parameter.
Finally, the mass flowrate expression becomes:
顆(ke)粒自由落體,然后再通(tong)過孔,即????????=√2??????。這(zhe)種(zhong)關系來自(zi)于這(zhe)樣(yang)一(yi)種(zhong)觀(guan)點，即(ji)堵塞機構是由于在(zai)孔(kong)口(kou)前形成半(ban)球形的拱(gong)。如(ru)果這(zhe)拱(gong)具(ju)有典型的孔(kong)徑大(da)小成正比的,我(wo)們(men)獲得??= 0、5。通常來講,參數??可以自由參數。
后，質量(liang)流(liu)量(liang)表(biao)達式為:
?? =
?? √2 ?? ?? 4
√?? (?? − ????????)2,5 = ???? √?? (?? − ????????)2,5
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