Section 1.2.3: Glossary of Chemical Engineering Terms
This module was written by chemical engineers, and most of the examples
have been drawn from this field. Several terms used in the module may
confuse people unfamiliar with this discipline. This section is intended
to explain some of these terms in a simple manner.
- without loss or gain of heat
- a specific mixture of components, which at a given pressure cannot
be separated by distillation, i.e. the liquid and vapour phases have
the same compositions.
- Bubble Point
- upon heating a liquid mixture, this is the point at which bubbles first appear.
- Continuous Stirred Tank Reactor. This may be thought of as a tank
to which reactants flow in, and products flow out. In an ideal CSTR
the contents of the reactor are uniformly distributed.
- Dew Point
- upon cooling a vapour mixture, this is the point at which droplets of
liquid first appear.
- containing more than one phase.
- containing a single phase.
- Two liquids are said to be immiscible, if when added together
they do not mix but form two separate liquid phases.
- Plug Flow Reactor. This may be thought of as a long pipe to which
the reactants flow in, and the products flow out. In an ideal PFR,
the components will be distributed axially, but will have uniform
- Reynold's Number
- This is a number which characterises flow. If the Reynold's number
is low (under approximately 1800) then the flow is said to be laminar.
This may be thought of as the fluid flowing in layers. If the Reynold's
number is high (over approximately 2300) then the flow is said to be
turbulent. Turbulent flow is considered to be well mixed.
- Vapour Pressure
- Vapour evaporates at the surface of a liquid. The pressure it exerts
is known as vapour pressure. The higher the temperature the greater
the vapour pressure.
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