Multistage Shelf Devices with Fluidized Bed for Heat-Mass Transfer Processes: Experimental Studies and Practical Implementation

Mykola Yukhymenko,Ruslan Ostroha,Jan Krmela,Nadiia Artyukhova,Artem Artyukhov,Jozef Bocko

doi:10.3390/app11031159

Mykola Yukhymenko, Ruslan Ostroha + Show 4 more

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https://doi.org/10.3390/app11031159

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Abstract

The article deals with the theoretical description and experimental study of the hydrodynamic and heat transfer properties regarding the operation of multistage gravitational devices of the fluidized bed with inclined perforated shelves. The peculiarities of the work and the implementation field of the multistage shelf units are described. A theoretical model to define the solubilizer’s velocity above the perforation holes, in the above-shelf space of the device and in the outloading gap, as well as the residence time of the dispersed phase at the stage (perforated shelf contact) of the device is presented. The results of experimental studies regarding the influence, made by the structural parameters of the perforated shelf contacts, on the distribution pattern of single-phase and gas-dispersed flows in the workspace of the device, on the intensity of interphase heat transfer are presented. The conditions to create active hydrodynamic operating modes of multistage gravitational shelf devices, which provide higher efficiency of heat-mass transfer processes, and with lower gas consumption and hydraulic resistance compared to typical fluidized bed devices, are proved. Peculiarities regarding the implementation of heat-mass transfer processes in multistage devices are described using heat treatment and drying processes as examples.

Highlights

Today the granular mineral fertilizers and bulk granular products are produced using several typical technological processing schemes
Most energy in the gas flow is taken for the hydrodynamic stabilization of the fluidized bed, the height of which reaches 0.2–0.5 m
Due to the creation of an active hydrodynamic mode to weigh solid particles in a layer, a multistage fluidized bed device with inclined perforated shelves provides efficiency to carry out heat-mass transfer processes

Summary

Introduction

Today the granular mineral fertilizers and bulk granular products are produced using several typical technological processing schemes. When developing technical plans for producing mineral fertilizers, developers and constructors face the difficulties in selecting the necessary equipment for the operating production departments, namely, for the granulation and enlargement of granules, their drying, cooling, and pneumatic separation. One should mention that despite effective processes in the fluidized bed, the heat-mass transfer ends at a low layer height, nearby the grid zone. In this case, most energy in the gas flow is taken for the hydrodynamic stabilization of the fluidized bed, the height of which reaches 0.2–0.5 m. It increases energy consumption and abrasion of particles, causing the necessity to install energy-intensive and metal-intensive dust cleaning systems

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