MATHEMATICAL MODEL AND EFFICIENCY OF GAS COOLING IN A SCRUBBER WITH BUBBLE TROWELS
Rubrics: 2. CHEMICAL TECHNOLOGY
Authors:
1.
KGEU
2.
KGEU
3.
Kazanskiy gosudarstvennyy energeticheskiy universitet
Type:
Article
Pages:
from 151
to 158
Status:
In work
Language:
Russian
Keywords:
HEAT AND MASS TRANSFER, GAS COOLING, BUBBLE LAYER, PHASE CONTACT, THERMAL EFFICIENCY
Abstract (English):
To solve problems of designing or upgrading industrial apparatuses in chemical engineering and power engineering, the process of contact cooling of gas in a developed bubbling layer on dip and sieve plates in scrubbers is considered. When compiling a mathematical model of heat and mass transfer, heat balance equations in integral and local forms are used to calculate gas and liquid temperatures, as well as moisture content. The method of heat and mass transfer number of transfer units is used to calculate the efficiency of gas phase processes. A model of ideal displacement of the gas phase along the height of the bubbling layer is adopted, using which the gas temperature at the outlet with plates is calculated. The temperature of the liquid phase is found from the solution of the differential equation of heat transfer with a volumetric interphase source or from the heat transfer equation in integral form (heat balance). Systems of equations of idealized models of transfer phenomena are presented, as well as taking into account the structure of the liquid phase flow. Expressions are given for calculating the Nusselt and Sherwood numbers in the gas phase, as well as the coefficient of turbulent thermal conductivity in the liquid phase. A model of local isotropic turbulence in the liquid phase core is used. Various modes of air cooling with water on dip and sieve trays are considered. The agreement between the calculated thermal efficiency of gas cooling and experimental data on a dip tray in a scrubber is shown depending on the gas velocity in the column at different heights of the bubbling (foam) layer. Calculated profiles of the liquid phase temperature along the tray length are given for various models. Conclusions are made about the applicability of the presented mathematical models depending on the regime and design parameters of the trays. The developed mathematical model can be used in the design, diagnostics and improvement of bubbling scrubbers for cooling gases in the fuel and energy complex, petrochemistry and other industries.
To solve problems of designing or upgrading industrial apparatuses in chemical engineering and power engineering, the process of contact cooling of gas in a developed bubbling layer on dip and sieve plates in scrubbers is considered. When compiling a mathematical model of heat and mass transfer, heat balance equations in integral and local forms are used to calculate gas and liquid temperatures, as well as moisture content. The method of heat and mass transfer number of transfer units is used to calculate the efficiency of gas phase processes. A model of ideal displacement of the gas phase along the height of the bubbling layer is adopted, using which the gas temperature at the outlet with plates is calculated. The temperature of the liquid phase is found from the solution of the differential equation of heat transfer with a volumetric interphase source or from the heat transfer equation in integral form (heat balance). Systems of equations of idealized models of transfer phenomena are presented, as well as taking into account the structure of the liquid phase flow. Expressions are given for calculating the Nusselt and Sherwood numbers in the gas phase, as well as the coefficient of turbulent thermal conductivity in the liquid phase. A model of local isotropic turbulence in the liquid phase core is used. Various modes of air cooling with water on dip and sieve trays are considered. The agreement between the calculated thermal efficiency of gas cooling and experimental data on a dip tray in a scrubber is shown depending on the gas velocity in the column at different heights of the bubbling (foam) layer. Calculated profiles of the liquid phase temperature along the tray length are given for various models. Conclusions are made about the applicability of the presented mathematical models depending on the regime and design parameters of the trays. The developed mathematical model can be used in the design, diagnostics and improvement of bubbling scrubbers for cooling gases in the fuel and energy complex, petrochemistry and other industries.
Keywords:
HEAT AND MASS TRANSFER, GAS COOLING, BUBBLE LAYER, PHASE CONTACT, THERMAL EFFICIENCY
HEAT AND MASS TRANSFER, GAS COOLING, BUBBLE LAYER, PHASE CONTACT, THERMAL EFFICIENCY
