Search Results (3)

Triboelectric separation, a solvent-free method, was investigated as a tool for protein enrichment in wheat flour. Gluten–starch model mixtures, flour, and reground flour fractions were evaluated for their separation characteristics (selectivity and efficiency). Mass yield, protein content, particle size distribution, and SEM analysis were used to assess performance. Selectivity and efficiency increased with gluten concentration, peaking at 63% for the 50% gluten mixture, but declined at higher concentrations. The 15% gluten benchmark demonstrated effective protein separation, with protein enrichment occurring in the ground electrode fraction and a corresponding depletion in the positive electrode fraction. In contrast, flour and reground flour fractions exhibited reduced separation efficiency, showing protein depletion in both electrode fractions due to agglomeration. The benchmark achieved the highest separation efficiency (47%), followed by reground flour (41%) and flour (7%). Finer particles in reground flour enhanced chargeability and GE deposition, while larger agglomerates in flour reduced efficiency, leading to material accumulation in the cups. Pre-milling helped detach protein and starch to some extent but also triggered re-agglomeration. Larger particles were influenced more by gravitational forces. These findings highlight the complexity of wheat flour fractionation and the need to optimize particle size and charge distribution to improve protein enrichment through triboelectric separation. Full article

This study explores a new perspective on triboelectrification that could potentially lead to the development of a non-destructive approach for the rapid characterization of powders. Sieved yellow pea powders at various particle sizes and protein contents were used as a model system for the experimental charge measurements of the triboelectrified powders. A tribocharging model based on the prominent condenser model was combined with a Eulerian–Lagrangian computational fluid dynamics (CFD) model to simulate particle tribocharging in particle-laden flows. Further, an artificial neural network model was developed to predict particle–wall collision numbers based on a database obtained through CFD simulations. The tribocharging and CFD models were coupled with the experimental tribocharging data to estimate the contact potential difference of powders, which is a function of contact surfaces’ work functions and depends on the chemical composition of powders. The experimentally measured charge-to-mass ratios were linearly related to the calculated contact potential differences for samples with different protein contents, indicating a potential approach for the chemical characterization of powders. Full article

The aim of this study was to investigate and analyze the impact of selected parameters during the tribocharging process of shredded poly(ethylene terephthalate) (PET) and high-density polyethylene (PE-HD) plastics on accumulated electric charge and electrostatic separation effectiveness. The accumulation of electric charge on surfaces of polymer particles as a result of their circular motion forced by the airflow cyclone container was investigated. The impact of the container material, time of tribocharging and the airflow intensity were experimentally examined. A container in which the particles of the considered polymers are electrified with opposite charges was selected. A high ability to accumulate surface charge on small particles of both polymers was demonstrated. The electrified mixed PET/PE-HD was subjected to a separation process. An electrostatic separator designed and constructed by the authors was used for to the separation. In turn, to assess the effectiveness of this separation, a dedicated vision system was used. Based on the result of the carried out tests, it has been assumed that the proposed approach’s effectiveness has been demonstrated by means of empirical validation. Full article