外文翻譯--攪拌性能比較單軸和雙軸攪拌機

1、<p><b>　　附錄：</b></p><p><b>　　外文資料與中文翻譯</b></p><p><b>　　外文資料：</b></p><p>　　Comparing mixing performance of uniaxial and biaxial bin blenders

2、</p><p>　　Amit Mehrotra and Fernando J. Muzzio</p><p>　　Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ, 08855, United States</p><p>　　Receive

3、d 17 February 2009; </p><p>　　revised 30 May 2009; </p><p>　　accepted 14 June 2009. </p><p>　　Available online 27 June 2009.</p><p><b>　　Abstract</b></p&

4、gt;<p>　　The dynamics involved in powder mixing remains a topic of interest for many researchers; however the theory still remains underdeveloped. Most of the mixers are still designed and scaled up on empirical

5、 basis. In many industries, including pharmaceutical, the majority of blending is performed using “tumbling mixers”. Tumbling mixers are hollow containers which are partially loaded with materials and rotated for some nu

6、mber of revolutions. Some common examples include horizontal drum mixers, v-</p><p>　　Graphical abstract</p><p>　　The dynamics involved in powder mixing remains a topic of interest for many re

7、searchers; however the theory still remains underdeveloped. Most of the mixers are still designed and scaled up on empirical basis. In many industries, including pharmaceutical, the majority of blending is performed usin

8、g “tumbling mixers”. In all these mixers while homogenization in the direction of rotation is fast, mediated by a convective mixing process, mixing in the horizontal (axial) direction, driven by a</p><p>

9、;　　Keywords:Powder mixing ; Cohesion; Blender ; Mixer; Relative standard deviation; NIR; Acetaminophen</p><p>　　Article Outline</p><p><b>　　1.</b></p><p>　　Introductio

10、n</p><p><b>　　2.</b></p><p>　　Materials and methods</p><p>　　2.1. Near infrared spectroscopy</p><p>　　2.2. Bin blenders used in this study: uni-axial blende

11、r (Blender 1), bi-axial blender (Blender 2)</p><p>　　2.3. Experimental method</p><p><b>　　3.</b></p><p><b>　　Results</b></p><p><b>　　4.<

12、;/b></p><p>　　Conclusion</p><p>　　References</p><p>　　1. Introduction</p><p>　　Particle blending is a required step in a variety of applications spanning the ceramic

13、, food, glass, metallurgical, polymers, and pharmaceuticals industries. Despite the long history of dry solids mixing (or perhaps because of it), comparatively little is known of the mechanisms involved [1], [2] and [3

14、]. A common type of batch industrial mixer is the tumbling blender, where grains flow by a combination of gravity and vessel rotation. Although the tumbling blender is a very common device, </p><p>　　How

15、ever, conventional tumblers, rotating around a horizontal axis, all share an important characteristic: while homogenization in the direction of rotation is fast, mediated by a convective mixing process, mixing in the

16、 horizontal (axial) direction, driven by a dispersive process, is often much slower.</p><p>　　In this paper, we experimentally investigate a new tumbling mixer that rotates with respect to two axes: a horizo

17、ntal axis (tumbling motion), and a central symmetry axis (spinning motion). We examine the effects of fill level, mixing time, loading pattern and axis of rotation on the mixing performance of a free-flowing matrix o

18、f Fast Flo lactose and Avicel 102, containing a moderately cohesive API, micronized Acetaminophen. We use extensive sampling to characterize mixing by tracking the e</p><p>　　2. Materials and methods</p

19、><p>　　The materials used in the study are listed in Table 1, along with their size and morphology. Acetaminophen is blended with commonly used excipients and is used as a tracer to evaluate the degree of homog

20、eneity achieved as a function of number of revolutions. Acetaminophen is one of the drugs most widely used in mixing studies, and Avicel and Lactose are commonly used pharmaceutical excipients. In the interest of brevi

21、ty their SEM images are not included in this paper, but can be found in “Hand</p><p>　　2.1. Near infrared spectroscopy</p><p>　　Acetaminophen homogeneity was quantified using near infrared spect

22、roscopy. A calibration curve was constructed for a powder mixture containing (in average) 35% avicel PH 102, 62% lactose and 3% acetaminophen. Near infrared (NIR) spectroscopy can be a useful tool to characterize acetami

23、nophen. Samples are prepared by keeping the ratio of Avicel to lactose randomized in order to minimize effects of imperfect blending of excipients during the actual experiments on the accuracy of the results. The R</p

24、><p><b>　　Fig. 1.</b></p><p>　　Fig. 1. Near Infrared (NIR) spectroscopy validation curve. The equation used to predict acetaminophen concentration is validated by testing samples with k

25、nown amounts of acetaminophen concentration. The y axis represents the concentration calculated from the equation and the x axis represents the actual concentration. Thus a perfectly straight line at 45° would repre

26、sent the best calibration model. Each point on the graph represents a single sample. The concentration of acetaminophen examined he</p><p>　　2.2. Bin blenders used in this study: uni-axial blender (Blende

27、r 1), bi-axial blender (Blender 2)</p><p>　　Due to its widespread use, a cylindrical blender 1 with a capacity of 30 L is chosen as a reference blender in the study. As shown in Fig. 2, this blender

28、 has a circular cross section and tapers at the bottom. It can be used with or without baffles, which are mounted on a removable lid. In this study all the experiments are conducted without the use of baffles. Mixing pe

29、rformance in this device is used to provide a base-line for evaluating the mixing performance of a newly developed b</p><p><b>　　Fig. 2.</b></p><p>　　Fig. 2. Pictorial representa

30、tion of (a) bin blender 1 and (b) bin blender 2 showing the corresponding axis of rotation.</p><p>　　2.3. Experimental method</p><p>　　Two types of initial powder loading used in the experim

31、ents: top–bottom loading and side–loading, which are schematically represented in Fig. 3. To avoid agglomeration, the API, acetaminophen, was delumped prior to loading it into the blender by passing it through a 35 mes

32、h screen. In order to characterize mixing performance, a groove sampler was used to extract samples from the blenders at 7.5, 15, 30, 60, 120 revolutions. The thief was carefully inserted in the bin, and a core was

33、 extr</p><p><b>　　Fig. 3.</b></p><p>　　Fig. 3. Schematic of the loading pattern used in the study. In top–bottom loading, Avicel is loaded first into the blender followed by Lactos

34、e on top of it and finally Acetaminophen is uniformly sieved over. In side–side loading avicel is placed at the bottom and then Acetaminophen is only sieved only in half part of the blender and is sandwiched between la

35、ctose and Avicel.</p><p><b>　　Fig. 4.</b></p><p>　　Fig. 4. (a) Thief sampler (b) top view of the sampling position scheme.</p><p>　　The experimental plan used in this st

36、udy is as follows:</p><p>　　? Fill level: blender 1–60%</p><p>　　? Fill level: blender 2–60%, 70%, 80%</p><p>　　? Loading pattern: blender 1 — side–side loading, top–bottom lo

37、ading</p><p>　　? Loading pattern: blender 2 — side–side loading, top–bottom loading</p><p>　　? Speed: blender 1–15 rpm, 20 rpm, 25 rpm</p><p>　　? Speed: blender 2 — rotational

38、/spinning:15/7.5 rpm, 20/10 rpm, 30/15 rpm</p><p>　　? Sampling time: blender 1, blender 2–7.5, 15, 30, 60, 120 revolutions</p><p>　　3. Results</p><p>　　The homogeneity index use

39、d is the RSD, where C is the concentration of each individual sample, C_? is the average concentration of all samples and n is the total number of samples obtained at a given sampling time.</p><p>　　We exami

40、ne the effect of fill level on mixing performance. Previously there have been studies on the effect of fill level in the Bohle bin blender, Gallay bin blender and V- blender and double cone blender [11], [12] an

41、d [13]. All the aforementioned blenders have only one axis of rotation, therefore the objective of this study is to examine how dual axis impact mixing performances at high fill levels. To avoid repetition, studies f

42、or fill level are not conducted for bin blender 1.</p><p>　　To examine the effect of fill level in a dual axis blender, experiments were performed in blender 2 with the top-bottom loading pattern for a

43、 rotational speed of 15 rpm and with spinning speed of 7.5 rpm. The fill levels examined are 60%, 70% and 80% respectively and samples are taken after 7.5, 15, 30, 60, 120 revolutions. Typical results are shown in Fig. 5

44、, which shows the RSD vs. number of blender revolutions. As expected for non-agglomerating materials, the curves show a rapidly decay</p><p><b>　　Fig. 5.</b></p><p>　　Fig. 5. Mixi

45、ng curves for different fill levels in blender 2. The RSD of acetaminophen is plotted as a function of number of revolutions. The loading pattern in top-bottom and the blender rotational speed is 15 rpm with spinnin

46、g speed of 7.5 rpm.</p><p>　　Similar to previous studies with other tumbling blenders we observe that blending performance is adversely affected by increasing fill levels. As shown in Fig. 5, the curve f

47、or 80% fill performs more poorly than those for 60% and 70% fill; as fill level increases, RSD curves decay more slowly, signifying a slower mixing process. However, the effect is not as pronounced as in other bin ble

48、nders and after about only 100 revolutions, the same plateau (the same asymptotic blend homogeneity) </p><p>　　Next, the effect of rotational speed is investigated in the blender 1 with one axis of rotati

49、on and is compared to the blender 2 with dual rotation axis. Experiments were conducted for both blenders with top-bottom and side-side loading. Experiments were performed at 60% fill level and the rotation speeds co

50、nsidered for blender 1 are 15 rpm, 20 rpm and 25 rpm respectively. As shown in Fig. 6 and Fig. 7, when plotted as a function of blender revolutions, there is not much of an effect o</p><p><b>　　Fig

51、. 6.</b></p><p>　　Fig. 6. Mixing curves for top-bottom loading experiments with 60% fill level. RSD is plotted as a function of number of revolutions. Dotted lines correspond to experiments in the b

52、lender 1, while solid lines represent data points from the blender 2.</p><p><b>　　Fig. 7.</b></p><p>　　Fig. 7. curves for side–side loading experiments with 60% fill level. RSD is

53、 plotted as a function of number of revolutions. Dotted lines correspond to experiments in the while solid lines represent data points from the 2.</p><p>　　Subsequently, experiments were performed using the

54、 blender 2 at three rotation speeds: 15 rpm, 20 rpm and 30 rpm, and as explained before, the corresponding spinning speeds were 7.5 rpm, 10 rpm and 15 rpm. Fill level considered for both side-side and top-bottom loadin

55、g was 60%.</p><p>　　Again, it was observed that varying rotation and spinning speeds did not make much difference in mixing rate. As shown in Fig. 6 and Fig. 7, mixing curves for blender 2 vary only sl

56、ightly with rotation speed. For the top-bottom loading pattern it appears that mixing improves slightly when rotation speed is increased (the plateau is slightly lower for higher rotation speeds, indicating an improvem

57、ent in the levels of asymptotic homogeneity), but no significant changes with speed are obser</p><p>　　The blending performance of both blenders is compared at different rotation speeds for both side-sid

58、e and top-bottom loading patterns. To make a fair comparison, the fill level was kept as 60% for both blenders, a condition for which both blenders achieve effective mixing at long enough times. Due to geometric si

59、milarity of the two blenders, this comparison help evaluate the effect of spin (rotation with respect to the central symmetry axis) on mixing performance. As shown in Fig. </p><p>　　Similar results were

60、obtained for the side-side loading pattern, as displayed in Fig. 7. The RSD curves for the blender 1 for all the three rotation rates lie above the blender 2. It is therefore confirmed that spinning a blender in di

61、rection perpendicular to the rotation axis helps in enhancing mixture homogeneity; however, for the materials examined here, the rotation rate does not have much effect on mixing performance. </p><p>　　Fina

62、lly, a comparison is made between the two loading patterns for both blenders. Again, to achieve a fair comparison, all experiments are performed at 15 rpm and 60% fill level. As evident in Fig. 8, in both blenders to

63、p–bottom loading gives a more rapid decay of the RSD, indicating faster homogenization as compared to side–side loading pattern. However, for both loading modes, blender 2 achieves faster homogenization.</p><

64、;p><b>　　Fig. 8.</b></p><p>　　Fig. 8. Comparison between the mixing curves of the blender 2 and the blender 1 for top–bottom and side–side loading pattern. Dotted lines correspond to expe

65、riments in the blender 1, while solid lines represent data points from the blender 2. Experiments are performed at 15 rpm with 60% fill level.</p><p>　　As reported in previous studies, all the RSD curves

66、 in this paper exhibit a common trend with respect to time, characterized by an initial period of rapid homogenization due to convective mixing, followed by a period of much slower homogenization typically controlled b

67、y dispersion or shear. This trend is shown schematically in Fig. 9. The first regime is a fast exponential decay and the second one is a slow exponential asymptote to a limiting plateau. The first part represents a rapid

68、 reductio</p><p>　　Fig. 9. A typical mixing plot, with RSD plotted against number of revolutions. The two solid lines emphasize on the two distinctive mixing regimes.</p><p>　　When only one

69、 mixing mechanism is present (a situation that can be achieved by careful control of the initial loading pattern), a simple mass-transfer model, represented in Eq. (1) can be used, as in past studies [14], to capture th

70、e evolution of the RSD in powder systems. In this model, an exponential curve decaying towards a plateau is fitted to the mixing curves, where σ is the standard deviation, σ∞ the final standard deviation, A is an integ

71、ration constant, λ signifies the mixing rate</p><p>　　)σ?σ∞=Ae?λN</p><p>　　The values for parameters A and λ are calculated by minimizing the sum of squares of errors between the data and an e

72、xponential function. The value of final standard deviation (σ∞) is taken as the lowest value of the variance achieved in the mixing studies. The values for λ are computed for blending experiments with different percent

73、age fill, and loading pattern and the results are plotted in Fig. 10 and Fig. 11. As shown in Fig. 10, the mixing rate constant decreases with increase in percen</p><p><b>　　Fig. 10</b></p&g

74、t;<p>　　Fig. 10. Mixing performance was evaluated at three different fill levels for blender 2. Experiments were performed at 60%, 70% and 80% fill levels at 15 rpm with top–bottom loading. Mixing rate const

75、ant (λ) values is plotted as a function of fill level and found to increase with decrease in fill level.</p><p><b>　　Fig. 11</b></p><p>　　Fig. 11. Mixing performance of bin blenders

76、 along with loading pattern are compared at 20 rpm with 60% fill level. Mixing rate constant (λ) values plotted for different loading patterns in bin blenders with and without baffle and as shown above, blender 2

77、givers a better mixing performance as compared to blender 1. There is also a pronounced effect of loading pattern, and regardless of the blender used, top–bottom loading always gives a better performance compared

78、 to side–side.</p><p>　　4. Conclusion</p><p>　　The effects of fill level, mixing time, loading pattern and axis of rotation on the mixing performance of a free-flowing matrix of Fast Flo lac

79、tose and Avicel 102, containing a moderately cohesive API, micronized Acetaminophen was examined. Blending performance was found to be adversely affected at increasing fill levels. Top–bottom loading pattern was shown

80、to lead to better mixing performance than side-side loading pattern. It was also confirmed that spinning a blender in direction p</p><p>　　References</p><p>　　[1] B.H. Kaye, Powder Mixing:

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96、/p><p><b>　　中文翻譯：</b></p><p>　　攪拌性能比較單軸和雙軸攪拌機</p><p>　　阿米特Mehrotra和費爾南多j的Muzzio</p><p>　　化工系與生化工程，羅格斯大學，皮斯卡塔韋，新澤西州，08855，美國</p><p>　　收到2009年2月17日;

97、</p><p>　　修訂09年5月30日;</p><p>　　接受09年6月14日。</p><p>　　可在線2009年6月27日。</p><p><b>　　摘要</b></p><p>　　所涉及的粉末混合動力仍然是許多研究者感興趣的話題，但是仍然落后的理論。該混頻器大多仍設計，規(guī)?；?/p>

98、的實證基礎上。在許多行業(yè)，包括醫(yī)藥，大多數(shù)的混合是使用“翻滾混頻器“。滾筒攪拌機是部分加載的材料和一些圈數(shù)旋轉中空容器。一些常見的例子包括水平滾筒攪拌機，V型混合機，雙錐混合機和bin攪拌機。在所有這些混頻器而在同質化是快速旋轉方向，由對流混合過程介導的，在水平（軸向）方向色散過程驅動，混合，往往是慢得多。在本論文中，我們探討一種新的翻滾實驗攪拌機，關于兩個軸旋轉：一個（翻滾動作）水平軸，中心對稱軸（旋轉運動）。進行詳細研究的粉末混合性

99、能和關鍵參數(shù)的影響，包括攪拌器的基本幾何形狀，速度，補平，擋板的存在，加載模式和旋轉軸。在這項工作中對乙酰氨基酚用作活性藥物成分和配方包含如常用Avicel和乳糖輔料?；旌闲实奶攸c，通過提取后，預先確定樣品的轉數(shù)來分析和近紅外光譜技術，以確定成分的分布。結果顯示過程變量包括粉末混合均勻性的旋轉軸的重要性。</p><p><b>　　圖形抽象</b></p><p>

100、;　　所涉及的粉末混合動力仍然是許多研究者感興趣的話題，但是仍然落后的理論。該混頻器大多仍設計，規(guī)?；膶嵶C基礎上。在許多行業(yè)，包括醫(yī)藥，大多數(shù)的混合是使用“翻滾混頻器“。在所有這些混頻器而在同質化是快速旋轉方向，由對流混合過程介導的，在水平（軸向）方向色散過程驅動，混合，往往是慢得多。在本論文中，我們探討一種新的翻滾實驗攪拌機，關于兩個軸旋轉：一個（翻滾動作）水平軸，中心對稱軸（旋轉運動）。</p><p>　

101、　關鍵詞：粉末混合;凝聚力;攪拌機，混合機，相對標準偏差;近紅外;對乙酰氨基酚</p><p><b>　　文章概要</b></p><p><b>　　1.簡介</b></p><p><b>　　2.材料和方法</b></p><p><b>　　2.1.近紅外光