| Popis: |
Air-and-peat mixture in horizontal jet transport pipeline is considered as a compressible two-component mixture with uniform distribution of solid peat particles in continuous air phase. Such heterogeneous medium flow is substituted for a flow of interpenetrating air phase and a quasi-solid phase approximating the flow of discrete particles. Such approach makes it possible to write individual equations of continuity and motion for each phase, but it is required to introduce the forces of aerodynamic interference at the phase boundaries in the motion equations. From the analysis of the known theoretical and experimental research data on jet transport of granular materials, it is possible to identify some parameters such that variation of any of these parameters changes the jet transport energy consumption. Such parameters are: jet capacity per mass of air and solid, Qair and Qs (kg/s) or input-output characteristic of mass concentration, μ = Qs/Qair; reduced velocities of air, Vair, solid particles, Vs, and soaring, Vsn, hereinafter called the flow-rate mode parameters, as well as the size and density of solid particles and the profile of the jet pipeline route. The flow-rate mode parameters are simply registered in the jet transport tests. The numerical determination procedure of the actual operating conditions of milled peat jet transport is justified. The known experimental data on jet transport of milled and treated peat are processed. It is found that the relative sliding ratio is functionally connected with all operating conditions in horizontal jet transport. The change of any parameter or their combination induces transition to air-and-peat mixture flow with various relative sliding of air and solid phases at different energy consumption of horizontal jet transport. |
