Elements of Particle Technology in the Chemical Industry

Abstract

Difficulties are encountered sometimes with new chemical products during manufacturing, handling, or marketing due to lack of knowledge in the particle technology area. The major problem discussed in this article is that, in most cases, this is due to the neglect of the mutual interactions between different unit operations during manufacturing and conveying in the design phase of these new products. Unlike the case with most other materials, it is not sufficient to know the present thermodynamic state of bulk powdery materials in order to determine their attributes since their ''history'' also affects the material's properties and behavior, often dramatically. The mutual effects between different operations such as bulk material handling, conveying, milling, and drying, as well as the property changes that occur during these processes, are discussed by presenting several case studies from the authors' own work and previous experiences. These include such properties as effective thermal conductivity, size distribution, flowability, caking, and surface activation in such operations as fluidized bed drying, pneumatic conveying, granulation, and tabletting. Finally, a flow sheet containing unit operations with powders is optimized using experience gained from these case studies.

Breakage probability of granules during repeated loading

“…In contrast to breakage resulting from progressive weakening due to damage accumulation, Petukhov and Kalman [26] reported of the increase in strength during repeated impact loading. This was confirmed by the pioneering works of Kalman and co-workers by integrating the testing methods with comminution systems (see [27,28]). …”

Continuous production of carbon nanotubes – A review

“…In the CVD method, bulk material handling is common for the process in which many problems encountered are attributed to the flow characteristic of the powders [37]. In truth, the scientific and engineering knowledge that govern the above conditions has been very much based on past performance [17]. Data provided by Merrow, (1985) for handling liquids or gases shows the ratio of actual to the designed production rate on average is about 90%, while particulate handling is roughly 40% with a variance of 40% [25], and this data provides the proof of a lack of scientific research.…”

“…Adapted from [28]. and caking [17]. These are attributed to particle size, shape, environmental conditions, cohesiveness, surface roughness, electromagnetic force, orifice diameter, wall effects and the angle of inclination, etc.…”