a device for singularizing bulk material includes an elongated trough having a longitudinal axis and a discharge end . the trough has an arcuate cross section and is inclined so as to slope downwards towards its discharge end . the upper end of the trough is connected to a motor which is capable of rotating the trough back - and - forth on its longitudinal axis . in operation , the trough is rotated back - and - forth and the bulk material is introduced into the trough at the upper end thereof . due to the inclination and back - and - forth movement of the trough , the particles of the bulk material travel towards the discharge end of the trough along zigzag paths thereby allowing the trough to be shortened . the back - and - forth movement of the trough also causes the particles to bump into one another and push each other aside during the course of travel so that effective singularization is achieved .