Simulation and calculation of pneumatic drying pipe taking into account longitudinal diffusion of drying agent

Based on the differential equations of material balance and mass transfer, the equations of the working and equilibrium lines were derived, taking into account longitudinal diffusion. An algorithm is developed and an example of calculation is given in comparison with the calculation using a typical algorithm that does not take into account longitudinal diffusion through the drying agent - air. It is shown that the longitudinal diffusion at the Peclet number Pe < 3,5 leads to the need to increase the height and, accordingly, the volume of the drying pipe by 10% or more, at Pe < 1 by 40% or more. In the ideal displacement mode, when Pe→0 (with a longitudinal diffusion coefficient Dl→∞), the increase in height and volume is more than 600%. Tables and graphs of the dependencies of technological parameters are given: temperature, enthalpy, humidity of dried particles, moisture content, etc. The obtained results are shown in the traditional oblique J-x Ramzin diagram and the additional rectangular Euler coordinate system, graphically demonstrating the graphs of the working and equilibrium lines of the drying process, taking into account and without taking into account longitudinal diffusion.