Mechanically design economics

The bubble cap has been studied extensively and several design recommendations have been presented over the years. The most complete and generally applicable is that of Bolles [5]. It should be stressed that proper mechanical interpretation of process requirements is essential in design for efficient and economic operation. There is not just one result, but a multiplicity of results, each unique to a particular set of conditions, and some more economical than others. Yet at the same time, many of the mechanical design and fabrication features can be identical for these various designs. 

Thermoeconomics of LHS systems involve the use of principles from thermodynamics and fluid mechanics and heat transfer. Therefore, thermoeconomics may be applied to both the use of those principles and materials, construction, and mechanical design, and a part of conventional economic analysis. The distinguished side of it comes from the ability to account the quality of energy and environmental impact of energy usage in economic considerations. 

A complete design includes consideration of all aspects of the equipment specification such that the item could be built and operated. These aspects include the mechanical design, materials selection, fabrication requirements, operational details, safety features, versatility (e.g. turn down), economic considerations, etc. The scope (i.e. depth) of the design should be clearly specified by the supervisor. 

It is evident that the process economics must be sound. This not only demands for much detailed attention to equipment selection and mechanical design, but also to forther process development and easy possibilities for modifications. 

Process integration and system synthesis require a skillful manipulation of system components. For example, heat exchanger network synthesis requires the utilization of very specialized methods of analysis [111, 112]. The search for an efficient system operation requires a multidisciplinary approach that will inevitably involve simultaneous utilization of heat transfer theory and thermal and mechanical design skills as well as specific thermodynamic considerations and economic evaluation. The optimal design of a system cannot be achieved without careful thermo-economic considerations at both system and component (i.e., heat exchanger) levels. 

A chemical reactor is a vessel manufactured from metal, often stainless steel or high resistant alloys. A minimum wall thickness is required to resist to different toads, and mainly to internal pressure. Accurate mechanical calculation of process equipment is a matter of mechanical engineering, and out of the scope of this book. Here we present only simple relations that permit the evaluation of weight and cost of vessels in a preliminary economic analysis. More information about mechanical design can be found in Coulson Richardson (1993). 

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