This paper presents the test results of a prototype installation for drying dispersed materials in a centrifugal fluidized bed. The prototype is a batch apparatus with a vertical supply of a drying agent. A diagram of a test bench designed to study the hydrodynamics of the apparatus and the heat and mass transfer process during drying in a centrifugal fluidized bed is given and described. Silica gel with a particle diameter of 3.8 mm was used as a dispersed material. Hydrodynamic experiments were carried out on a “cold” model. Based on their results, the relationship of the hydraulic resistance of the apparatus at various values of the air velocity and mass of material in the working chamber is constructed. Experimental data have been obtained on low-temperature drying of silica gel in a centrifugal fluidized bed for various modes. The data are presented as time relationships of the temperature and humidity of the material and the drying agent. Analysis of the data obtained showed that the heat and mass transfer process in a centrifugal fluidized bed has a high intensity. A positive conclusion is made about the possibility of using this apparatus for low-temperature drying of capillary-porous bodies.

Nowadays, the units with a fluidized bed hold a special place among all heat-mass transfer plants currently used in industry. First of all, it is due to the highly developed surface of interaction between the fluidizing agent (air) and dispersed materials in such units, their low hydraulic resistance, relatively simple design and small sizes. At the same time, the units with a centrifugal fluidized bed, which is formed in an annular channel of the working chamber when a fluidizing agent is added under the fixed angle, are of particular interest. Currently, a limited number of experimental and theoretical studies of hydrodynamics and heat-mass transfer in a fluidized bed are known. Besides, these studies were carried out mainly in respect to regenerative heat exchangers and absorbers. In this regard, such studies in respect to the devices for other purposes, such as dryers, seem to be relevant. The results of these studies are the scientific backgrpund for development of an engineering calculation methodology of such units and their design. The study has been carried out based on an experimental plant using means for measuring temperature, relative air humidity, differential pressure, air velocity, and moisture content of solids. A TPM 148 PID controller has been used as a secondary device. Experimental data have been recorded in MasterSCADA SCADA system. Data processing has been carried out using interpolation by cubic splines. The article describes in detail an experimental plant that allows carrying out a full factor experiment to study the hydrodynamic and thermal parameters of a convective dryer with a centrifugal fluidized bed. The article presents the results of a preliminary series of experiments in which silica gel is used as a dispersed material. As a result of visual observations over the dispersed material in the working chamber, the values of the minimum and maximum speed of the drying agent have been determined. The grafic relationship of the hydraulic resistance of the working chamber and the height of the material layer are obtained depending on the speed of the drying agent and the mass of the material, as well as the temperature and moisture content of the material and the drying agent depending on the drying time. The results obtained make it possible to determine the design and operational parameters of the centrifugal fluidized bed drying plant and select a fan to supply the drying agent.

In this paper, the design and principle of operation of the dryer with a centrifugal fluidized bed is considered. It is a batch apparatus with a vertical drying agent supply and is intended for drying dispersed materials with a particle diameter from 1 to 5 mm, having a high initial moisture content and a strong moisture and solid dry frame bond. Silica gel with a particle diameter from 2.2 to 2.5 mm, used for drying air and industrial gases, was used as a drying object. The scheme of the test bench is given and described. The results of an experimental study of the process of low-temperature drying of silica gel (the temperature of the drying agent ranged from 35 to 65 °C) are presented. The obtained experimental data is presented as a dependence of the thermophysical parameters of the material and the drying agent on the drying time. The comparison of drying efficiency at different modes is given. On the basis of the obtained data, a positive conclusion about the possibility of using this apparatus for low-temperature drying of capillary-porous bodies is made.

This paper considers the increasing the mass transfer intensity due to the use of annular baffles in the tubes of shell-and-tube heat exchange apparatuses. A mathematical model for calculating the system of equations for the evolution of particle distribution in the form of sediments has been developed.

In this paper, we consider measures to reduce the amount of deposits in heat exchange tubes and increase the intensity of heat exchange through the use of annular notches-turbulators in tubes of shell-and-tube heat exchangers.