ANTE: Abstracts in New Technologies & Engineering

Determining particle shape is vital for many industrial processes such as those found in the pharmaceutical, agricultural, and bioenergy industries. With modelling being an essential tool to acquire an understanding of the behaviour of particulates in industrial processes, numerical methods such as DEM are needing numerical solutions to formulate and implement particle shape models that overcome current limitations. Whereas pharmaceutical particles have a regular shape, agricultural and biomass particles often are specific, irregular and non-analytic. Because the diversity of real shapes is enormous, a variety of methods for describing particle shapes currently exist. Recently, the series of spherical harmonics (SHs) has gained much interest through their application in many other fields. This paper focuses on the application of the semi-analytical SH technique and addresses the development of a universal modelling tool for describing different particle shapes using a finite number of SHs. The results obtained from modelling pharmaceutical, agricultural, and biomass particles prove the applicability of SHs to regular as well as irregular shapes. In this regard, their optimised description by minimising the number of non-zero expansion coefficients is demonstrated. To proceed with a smaller number of low-order SHs, surface segmentation is introduced. Sufficient accuracy in the shape description of the particles selected was achieved with less than 16 SHs.

This paper presents a novel concept of local push-pull ventilation system used to removeaerosol particles from open surface tanks. Sound waves generated by aerodynamic soundgenerator are introduced into the push air flow of lateral exhaust hood and used toagglomerate aerosol particles. Results of calculation of parameters of sound generator andaeroacoustic air flow are presented. It is established that 5–10 μm aerosol particles areaggregated better at frequencies below the ultrasonic range (1–5 kHz) and aerosols witha particle size of less than 5 μm are more effectively aggregated at ultrasonic frequencies. Itwas experimentally established that the relative air humidity measured above open surfacetank is decreased up to 1.6 times in presence of acoustic field as compared with humidityobtained for conventional push-pull air removal system. It is also obtained that increaseof the temperature of the liquid increases the aerosol removal efficiency of lateral exhausthood enhanced by aeroacoustic air flow.