Page 55 - Design of Simple and Robust Process Plants

3.3 Design Philosophies 39
3.3.2
Long Term

The element of ªlong termº emphasizes that we must have an ongoing, good rela-
tionship with customers and the community. Customers are satisfied by consistently
low prices, good quality of products, and deliveries on time. Today, the communities
represent moving targets, and the increasing standards of living of communities,
together with the recognition that we must create a sustainable world for future gen-
erations, places a large responsibility on the shoulders of all civilians. In order to
satisfy these moving targets we must do more than simply conform to changing
local requirements. As a result of the increases in standards of living, the risk and
nuisance requirements of communities become increasingly stringent, next to pol-
lution loads, and a long-term vision with regard to environmental requirements is
needed. The requirements include for example the ban on ozone-depleting gases,
the CO 2 targets, and ongoing efforts to develop a sustainable world.
The ten design philosophies to be discussed must satisfy the ultimate objective of
the competitive plant.
Design philosophies can be approached from three different perspectives:
1. Design of simple and robust chemical plants (Koolen, 1998);
2. World class manufacturing (Schonberger, 1986); and
3. Inherently safer and environmentally sound chemical processes.

The Design of Simple and Robust Chemical Plants

3.3.3
Minimize Equipment, Piping, and Instruments

The title of this philosophy may seem surprising, since it is unlikely that equipment
that is not needed would be installed at all! The answer should be found in the way
that engineers develop designs: they are accustomed to thinking and working in a
sequential mode, and generally also have some fall-back (default) solutions at hand,
some of which might include:

. When we need to transport a liquid, the fall-back design will be to select a
pump and specify its type. Wrong! The first two questions to be asked should
be:
1. Do we need to transport the liquid? ± and are there any alternatives?
2. What will be the best way to transport the liquid? (Think about gravity
flow, flow on pressure difference, before the default pump is selected.)
. When we need to move large quantities of materials, we design an inventory
facility at the distribution point and at the receiving point. The first two ques-
tions to consider are:
1. What will the most economical way? Do we need to move the material? ±
what might be the alternatives?