The dissertation work is devoted to the study of heat and mass transfer equipment for sorption processes in direct contact of gas and liquid using combined plate-packed bed block in column apparatuses, as well as a deeper description of this process, which is an actual task of chemical technology.
It was proposed to place special separators in the separation space between the hole plates to reduce the harmful effect of splashing on the efficiency of the hole plates. Such separators work as foam layer stabilizers when the device is operating in a developed bubbling mode, and they themselves are an additional phase contact zone, so the introduction of combined plate- packed bed contact devices in one column is a promising direction of scientific research. It is possible to increase the efficiency and intensity of separation processes, avoid liquid splashing in existing column heat and mass transfer devices.
The dissertation presents the developed models of flow interaction in combined block plate-packed bed devices that allow us to determine the hydrodynamic parameters and characteristics of the process.
A mechanism for the formation of phase flows in a block contact element is proposed; the existence of several zones of the gas-liquid system is revealed. During physical simulations, the hydrodynamic characteristics and limit modes of operation of the contact sections were determined. Dependences of the foam layer height and hydrodynamic resistance of the contact stage are obtained to determine the main operating parameters of the column device with combined contact elements under consideration. It is established that hole plates with a larger free cross-section work more stably than hole plates of with a smaller free cross-section.
The design characteristics of foam layer stabilizers necessary for achieving a high degree of separation are justified. The set height of the stabilizer above the plate is in the range of 100-120 mm. It is shown that when using foam layer stabilizers, the gas content in foam at the contact stage is reduced, which leads to more stable and uniform operation of the device.
In the dissertation work presented the mechanism of splash removal in a combined contact element and provides empirical dependences for determining the amount of splash. Equations for calculating the lower and upper limits of operation of a combined contact element are given.
Based on physical modelling, the dependences for calculating the efficiency of the combined contact element on the mode and design parameters were determined, which adequately describe the processes observed in experimental studies, and show a fairly high correlation with experimental data in the range of 5-20%,
An improved device for washing air filters and a gas washer of columns I and II in the production of soda ash, as well as the use of the studied structures in scrubbers for capturing dust or organic substances, are proposed with combined plate- packed bed contact sections.
In industrial conditions, when modernizing existing process lines for the production of soda ash, when using the results of the dissertation work, the proposed process gas purification system will provide a degree of purification from 96,4 – 99,0%, and the indicators of the separation process will meet the requirements that are necessary for the reliable operation of process lines.
Based on the theoretical and experimental studies performed in the work, scientifically based practical recommendations for the design and engineering methods for calculating column apparatuses using block plate- packed bed contact elements based on a combined principle are developed in order to increase the efficiency of separation processes and reduce hydraulic resistance, with the determination of rational design parameters of elements of separation systems. The results of the work are implemented in business contracts, research projects and in the educational process, which is confirmed by the relevant acts of application.
