Separation of bran from bulgur through tribocharging with Teflon

Abstract

In this study, the use of an electrostatic field on a Teflon surface to separate free bran from bulgur during processing was investigated. The results suggest that this method could be an effective solution to the problem of free bran, which can negatively impact the appearance and quality of bulgur in bulgur processing and packaged products. Unlike traditional methods, a novel technology was used with the device having flat and folded Teflon surfaces (flat and folded inclined channels). The device was designed with the widths of 4, 5 and 6 cm, the lengths of 20, 40 and 60 cm and the angles of 30, 35 and 40°. The flat Teflon system produced the best results overall. In addition, the design parameters of 4 and 5 cm width, 20 and 40 cm length, and 35 and 40° inclination were suitable for separating bran from bulgur using an electrostatic system. As a result, a fine bulgur mixture containing 5 g of bran per 1000 g of bulgur was passed through the system at a flow rate of 0.89 g/s, resulting in a reduction of bran in bulgur from 5 to around 2 g (around 60% reduction).