Growth kinetics of nuclei formed from different binders and powders in vertical cylindrical mixing devices

Abstract

Granulation is the process of forming large aggregates from fine particles using a high shear mixer. This method is used in several industries from pharmaceuticals to chemical and fertilizer production. This research will study the effect of four process variables: speed of mixer rotation in the range 100 to 200rpm, powder bed mass (25 to 40g), mass of the initial nucleus (0.6 to 2g), and binder viscosity (water, carboxymethyl cellulose (CMC) solutions with concentrations in the range 0.5 to 20g/L) on single nuclei growth kinetics in low mixing devices. The powders under study were: lactose, tea, sugar, starch, and limestone. The results show the initial size of nuclei, the initial mass of the powder bed and binder viscosity and speed of rotation all influence the rate of nuclei growth. Analysis of the stokes deformation number of the nuclei show that growth rate of the nuclei decreases as the deformation number increases whilst the percentage gain in mass of the nuclei increases with increasing deformation number. The binder viscosity was shown to have the biggest influence of the growth rate of the nuclei. Results show that difference in powder density also has an effect on the growth kinetics of nuclei. The initial position of nuclei was also shown to influence the nuclei growth rate; the closer the starting position of the nuclei to the wall of the vessel the slower the growth rate.

Production of bio-waste granules and their evaluation as adsorbent for removal of hexavalent chromium and methylene blue dye

“…However, the loss of adsorption capacity between the S0 and S5 samples was about 23% compared to 3% in the case capacity towards chromium removal. The adsorption capacity of the granule with respect of MB reported 39 mg/g is comparable to values reported in previous work [14,15,[19][20][21].…”

Production of solid biofuel granules from drum granulation of bio-waste with silicate-based binders

“…Different drum speeds (22, 27, 32, 37 and 42 rpm) were studied with a granulation time of 15 min. In order to predict the results for drums with different diameters and different scales, the Froude number (Fr) was also determined using the equation below [26]:…”

“…To further validate the results obtained, Stokes deformation number (Stdef) for granulation processes using different concentrations of sodium silicate binders were calculated (Table 4). The Stdef reflects the ratio of externally applied kinetic energy in the system to the energy required for deformation of the granules and it is given as below [26,33]:…”

Influence of cellulose additive on the granulation process of potassium dihydrogen phosphate

“…Granulation rows that have low plasticity, such as dolomite, ash and others, are difficult to granulate in the absence of additives. Therefore, various binders are often used to improve agglomeration [17,18].…”