Environmental impact reduction in the ceramics industry: conveying parameters control for atomized slip pneumatic transport

Atomized slip conveying in the ceramics industry is currently carried out by conveyor belts that pick up the material from the spray nozzle bottom and then cover long distances, crossing the working environment and rising up to stocking silos. All these operations cause a long exposure of atomized slip in the working environment. Because of the nature of atomized slip, it is very difficult to avoid the diffusion of fine particles in the environment, which increases with the belt speed. Very expensive suction plants for picking up fine particles have frequently been installed, but often without accomplishing the task with the required efficiency. Pneumatic conveying of atomized slip fully solves dust pollution problems in the working environment. However, two fundamental parameters need to be controlled to make pneumatic conveying of the atomized slip sustainable: product wear and humidity. Both solid maximum conveying velocity and gradient (i.e. the variation of solid velocity, in m/s, in one meter of pipe) velocity need to be limited to guarantee product wholeness. As regards product humidity, it could be controlled by air humidity, pressure and temperature. By means of a software simulator (TPSimWin) [2,3,4] it is possible to foresee conveying parameter values that give the atomized slip the characteristics required by the following working processes. This paper analyzes the main plant characteristics needed to design an atomized slip pneumatic conveying with controlled thermo-hygrometical and fluid-dynamical parameters.