EXPERIMENTAL-STUDY ON THE PREPARATION OF AIR-SOLID MIXTURES IN A VENTURI INJECTOR

Our investigations deal with the injection of solid products through a venturi injector into a pneumatic conveying installation. The princip le of such a system and our experimental apparatus are described, Resu lts reported here concern a large range of powder concentrations in th e air-solid flow, and especially injections at high solid flow rate th at have so far been poorly studied, Flow behaviours through the differ ent singularities of the injection system are described, The influence of the particle characteristics, and especially their shape, was show n to be important. The energetic cost of product aeration and particle acceleration was estimated by calculating the pressure loss coefficie nt through the venturi injector and the necessary power, We finally pr opose a method to calculate the mixing flow parameters in the injectio n region using coefficients deduced from our experimental results.