催化剂颗粒流的基本方程及其应用(Ⅰ)

THE BASIC EQUATION AND THE APPLICATIONS OF CATALYST PARTICLES FLOW(Ⅰ)

本文借助于土力学和流体力学等的基本方法,对催化剂颗粒流作了五点假设,建立了封闭的动力学基本方程.为求解移动床和管道内催化剂的高密度重力流、固定床和高密度输送流等奠定了基础。

Making use of the basic methods of structure mechanics of loose parti- cles bulk,solid mechanics,viscous fluid dynamics and elastic mechanics,the present paper has found a set of the closure basic equations on catalyst par- ticles flow.They provide some theoretical basis for the design of moving -bed and the gravity flow of catalyst particles in pipes. In order to abstract catalyst particles flow into the ideal mechanical model,we consider catalyst particles flow satisfying the following five hypo- theses:(1) the space is inseparable and continuously occupied by catalyst;(2) the mechanical characters of catalyst are even and isotropy;(3)the shearing strength in catalyst particle bulk is a linear function with normal stress on shearing plane;(4) single particle in catalyst particles flow has no spinning during the movement.But,because the particles keep in the flow state,the particle bulk has sliding planes as plastic bulk,there is a sliding motion in the particle bulk;(5)a particle in the catalyst particles flow has much more greater flow displacement due to the change of pressure and stress in parti- cles bulk.Therefore,when we study catalyst particles flow,we can consi- der the particles bulk to be incompressible. The catalyst particles flow has both the characters of fluid flow and the characters of elastic and plastic bulk during the particles flow.Then we may think the flowing particles bulk has to satisfy the conditions of mechanical equilibrium,continuity,flow and stress-strain,etc.Therefore,we obtain a set of equations of momentum conservation,mass conservation,maximum equilibrium and stress-strain.This set of equation is closure and solutionable from the viewpoint of mathematics.Also,we obtain a kinetic energy equition for catalyst particles flow.