Research On The Relationship Between Fractal Denotation Of Organic Powder And Flowability

In the powdery industry and productes,the application of organic powder occupy in the most of industry, such as foodstuff,medicine,agriculture and materials.The research contents of powdery industry contains that of the property and denotation of powder particle,storage and transportation, preparation and manipulation,and so on.powder particle fluidity directly effect the various production organization of processing,equipmentary design and the selection of engineering parameter.The measure of powder partical fluidity a is of great significance to powdery industry s an important reserach subjiect of powdery engineering.powder scale (including partical size,partical size distribution,surface area,shape and so on)have a relationship with adhesion and fluidity.using fractal theory to measure powder granular characters and partical size distribution will make an great contribution to development and progress of poedery industry.In the molecule size, powder particles is not a regular geometry, it can display complex edge and rough surface.powder particle fractal dimension can nicely display the subtle structure of powder partical,we can introduce the particles research into micro-field to deeply understand the relationship between the physical and chemical properties and subtle structure.taking organic powder particle,which is commonly used in feedstuff industry, as an research object, establishing mathematical model of surface and boundary fractal dimension to investigate the relationship between the fractal dimension and fluidity.Based on the SEM images of organic powder particles, with Box counting method and MATLAB, it realized the measurement of surface and boundary fractal dimension, all equation were highly significant (P<0.01) through the regression analysis of the result, it demonstrate that the Box counting method is reliable. Based on the Box counting method, it spreads the Information dimension and Differential box counting method of calculation, Information dimension can goodly reflact unuiform change of fractal sets, grasp subtle structure more accutely and have a more accute calculation. Differential box counting can well reflact the extent of irregular of powder partical by gray value change of image surface.By Carr theory, physical index of powder fluidity denotation were measured. Carr index comprehensively characterize powder fluidity mainly by slop angle, flat angle, compression degree and aggregation degree. The larger the slop and flat angle, including that the larger agglomeration force and more easily accumulating; the larger compression degree, the larger gap rate between the powder particles aggregation degree can characterize the situation of powder particles size distribution.By linear fitting between Carr index of powder particles and fractal dimension that measured by fractal model, the linear equation between Carr index and Box dimension Db is F=-119.295Db+217.218;the linear equation between Carr index and Information dimension Di is F=-105.320Di+199.850;the linear equation between Carr index and Differential box dimension Dbc is F=-80.368Dbc+216.062;the equation between Carr index and the two variance of Dbc and Di is F=-85.2Di-25.370Dbc+224.680.By F test and t test of the linear equation,the test results show that regression coefficient and regression equations were significant and extremely significant, indicating that there exists linear relationship between fractal dimension and Carr index, and particularly boundary fractal dimension is more significant to equation, and also that the fractal dimension can be characterized the powder fluidity.