Центральноукраїнський науковий вісник. Технічні науки. Випуск 6. Частина 2. - 2022
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Item Теоретичні дослідження процесу руху сипучих будівельних матеріалів при сушінні в киплячому шарі каскадної сушарки в будівництві(ЦНТУ, 2022) Скриннік, І. О.; Федотова, М. О.; Дарієнко, В. В.; Skrynnik, I.; Fedotova, М.; Darienko, V.В роботі розглянуто систему рівнянь руху потоку матеріалу, яка дозволяє визначити швидкість, траєкторію переміщення частинок, а також час перебування частинок у вільному робочому просторі апарата. Суттєвий вплив на визначення необхідного часу перебування частинок в апараті, чинить не тільки гідродинаміка потоків, а і кінетика процесу сушіння в апаратах киплячого шару. Дана робота присвячена розгляду саме цих нюансів. The paper considers the system of equations of movement of the material flow, which allows to determine the speed, trajectory of movement of particles, as well as the time of stay of particles in the free working space of the apparatus. Not only the hydrodynamics of flows, but also the kinetics of the drying process in fluidized bed devices (the particle changes its mass during drying, which is reflected in the mode of its movement) has a significant influence on the determination of the required residence time of the particles in the apparatus, which has contact actions with the cascade. A promising way to reduce material and energy costs during heat and mass exchange processes in a fluidized bed is the use of multi-stage countercurrent contact of the liquefying agent and the dispersed phase. Such processes are implemented in cascade-type devices. It should be noted that the analytical dependences presented do not yet allow a reliable description of the hydrodynamics of the movement of solid particles in a device with contact devices. This is due to the fact that the proposed analytical regularities do not take into account the influence of the main design parameters of the cascade contacts on the time the particles stay in the working space of the device. The efficiency of drying devices for drying materials in a fluidized bed largely depends on the flow field of the gas flow, the distribution of which in the working space of the device affects the profile of temperatures and concentrations of the dispersed (solid) phase in the gas flow. Determination of gas flow velocity fields in the working space of the fluidized bed apparatus in combination with calculations of the rate of transition of a dense layer of material into a fluidized state, conditions of expansion of the material layer, operating parameters of fluidization, and conditions of removal of material from the apparatus allows for optimal selection of the design characteristics of this type of apparatus. Consideration of the nature of the movement of the gas flow is important for establishing the regularities of its interaction with the solid phase. Determining the hydrodynamic conditions of flow movement makes it possible to mathematically describe the speed and residence time of solid particles in the apparatus.