Page 19 - Plant design and economics for chemical engineers

2 PLANT DESIGN AND ECONOMICS FOR CHEMICAL ENGINEERS

This brief outline suggests that the plant-design project involves a wide variety
of skills. Among these are research, market analysis, design of individual pieces
of equipment, cost estimation, computer programming, and plant-location sur-
veys. In fact, the services of a chemical engineer are needed in each step of the
outline, either in a central creative role, or as a key advisor.

CHEMICAL ENGINEERING PLANT DESIGN
As used in this text, the general term plant design includes all engineering
aspects involved in the development of either a new, modified, or expanded
industrial plant. In this development, the chemical engineer will be making
economic evaluations of new processes, designing individual pieces of equip-
ment for the proposed new venture, or developing a plant layout for coordina-
tion of the overall operation. Because of these many design duties, the chemical
engineer is many times referred to here as a design engineer. On the other hand,
a chemical engineer specializing in the economic aspects of the design is often
referred to as a cost engineer. In many instances, the term process engineering is
used in connection with economic evaluation and general economic analyses of
industrial processes, while process design refers to the actual design of the
equipment and facilities necessary for carrying out the process. Similarly, the
meaning of plant design is limited by some engineers to items related directly to
the complete plant, such as plant layout, general service facilities, and plant
location.
The purpose of this book is to present the major aspects of plant design as
related to the overall design project. Although one person cannot be an expert
in all the phases involved in plant design, it is necessary to be acquainted with
the general problems and approach in each of the phases. The process engineer
may not be connected directly with the final detailed design of the equipment,
and the designer of the equipment may have little influence on a decision by
management as to whether or not a given return on an investment is adequate
to justify construction of a complete plant. Nevertheless, if the overall design
project is to be successful, close teamwork is necessary among the various
groups of engineers working on the different phases of the project. The most
effective teamwork and coordination of efforts are obtained when each of the
engineers in the specialized groups is aware of the many functions in the overall
design project.

PROCESS DESIGN DEVELOPMENT

The development of a process design, as outlined in Chap. 2, involves many
different steps. The first, of course, must be the inception of the basic idea. This
idea may originate in the sales department, as a result of a customer request, or
to meet a competing product. It may occur spontaneously to someone who is
acquainted with the aims and needs of a particular compaqy, 8r it may be the ,. _
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