A new energy dissipation theory of jig bed stratification. Part 1: energy dissipation analysis in a pilot scale baum jig

Abstract

The dynamic energy dissipation within a jigging cycle has been mechanically analyzed using data developed in a highly instrumented and controlled pilot scale Baum jig. The analysis is based on the use of the energy and momentum equations for the fluid. It was found that energy balances on the water in the jig failed to close because of elastic deformation of the jig body, rather than inaccuracies in the measurement techniques or failure to account for heat transfer. This deformation problem appears to be common in either pilot jigs or commercial jigs. An empirical means of correcting the energy balance was devised and applied to the data with some success. Using this compensation method, the energy balance was improved. The likely energy balance indicates that (i) less than 7% of the energy of the incoming compressed air is expended in the jig system, (ii) less than 5% of the energy from the compressed air is actually dissipated in the jig bed, (iii) the kinetic energy input from the hutch water supply is effectively negligible, in comparison to the energy input from the compressed air, and (iv) about 2.5-3.7% of the energy from compressed air is dissipated around the bed plate