Thermal process engineering

H.-J. Bart Institute of Thermal Process Engineering, University of Kaiserslautern, Kaiserslautern, Germany... 

From the area of thermal process engineering, the mass and heat transfer in stirred vessels and in bubble columns is treated. In the case of mass transfer in the gas/liquid system, coalescence phenomena are also dealt with in detail. The problem of simultaneous mass and heat transfer is discussed in association with film drying and in continuous electrophoresis. 

Professor (em.) Institute of Thermodynamics and Thermal Process Engineering University of Stuttgart 70550 Stuttgart Germany... 

Institute of Process Engineering Chair of Thermal Process Engineering P.O. Box 4120 39106 Magdeburg Germany... 

The equations of change of linear and angular momenmm are relevant to the mechanics of fluids and solids. The equation of change of energy and the subsequently derived equations are of fundamental importance to thermal process engineering and are discussed in the following. 

The following section renders correlations, with which it is possible to determine heat and mass transfer coefficients for some cases significant to thermal process engineering. 

The importance of membrane processes in separation technology is steadily increasing. Membranes separate a feed mixture into a permeate, that is, the part of a stream which passes the membrane, and a retentate, which does not pass the membrane (Figure 9.2). In thermal process engineering, membrane separations are often an energy-saving alternative for the separation of azeotropes, as the separation effect is almost independent from the vapor-liquid equilibrium which is used in distillation. The two components separate because of their different ability to pass the membrane, which is illustrated in Figure 9.2. 

Thomas Gruetzner and Hans Hasse, Solubility of Formaldehyde and Trioxane in Aqueous Solutions, Institute of Technical Thermodynamics and Thermal Processing Engineering, University of Stuttgart, Stuttgart, Germany. 

Prof. Evangelos Tsotsas Otto von Guericke University Thermal Process Engineering... 

Usually, natural gas treatment on the basis of thermal process engineering takes place in three steps (see Fig. 7.9). The first step that may consist of partial steps just like all other subsequent steps, serves the preparation of the crude gas for its processing. Here, for example, acid-forming gas components, such CO2, H2S and other sulphuric compounds are removed. Usually, chemical scrubbing with amines (MEA, DEA, MDEA) is applied in which the adsorbent is being regenerated. Then the natural gas is dried. In case of moderate water dew point requirements, glycol is used as wash liquor. The lowest water contents (< 1 ppm) are achieved with the application of zeolitic molecular sieves. Finally, mercury is removed in case aluminium will be used as material of construction for equipment. Mercury in contact with aluminium may lead to catastrophic corrosion. 

At that time and still today, typical process steps involve distillation as well as drying - process steps which can be attributed to the area of thermal process engineering. 

Process simulation Process simulation software is used for the planning and layout of processes in entire systems or plant units. The range of competence of these software systems typically comprises the calculation of procedural basic operations, mainly in chemical and thermal process engineering according to the principle of the conservation equations for mass, matter, momentum and enthalpy in consideration of the principles of thermodynamics. A typical example is the calculation of the matter and heat transmission in rectification columns. Here, the acquisition of correspondingly reliable matter data is often difficult. Therefore, the simulation results are generally accompanied by the respective experimental studies. 

In thermal process engineering, packed columns as well as tray columns are often used for heat and mass transfer processes in rectification, absorption and extraction as well as for the cooling of gases and liquids and wastewater and groundwater treatment. They are mainly used for counter-current gas/liquid flow. Figure 1-1 shows the schematic structure of a packed column with random packing elements. 

The simple design of packed columns makes them suitable for the most important basic operations in thermal process engineering - rectification, absorption, desorption and extraction - using various column internals, including the more conventional metal and ceramic ones as well as packing elements made of plastic. 

One of the author s priorities was the practical aspect of the work, since the standard approach to rectification, absorption and extraction as the core areas of thermal process engineering is purely empirical. 

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