Module 3 Flashcards
(154 cards)
________ is an essential element of many pharmaceutical processes. The ability to propel fluids through pipes and to direct materials from one
location to another is central to the successful manufacture of many products.
Fluid flow
_________ are a form of matter that cannot achieve equilibrium under an applied shear
stress but deform continuously, or flow, as long as the shear stress is applied.
Fluids
___________ is a property that characterizes the flow behavior of a fluid, reflecting the
resistance to the development of velocity gradients within the fluid.
Viscosity
Fluids having constant viscosity
and a zero shear rate at zero shear
stress
Newtonian Fluid
Fluids having variable viscosity,
and a variable relationship with
shear stress
Non-Newtonian Fluid
Deformation is not only a shear-induced phenomenon. If the stress is applied
normally and uniformly over all boundaries, then fluids, like solids, decrease in volume. This decrease in volume yields a proportionate increase in density.
COMPRESSIBILITY
______________ a property confined to a free surface and therefore not applicable to
gases, is derived from unbalanced intermolecular forces near the surface of a liquid.
This may be expressed as the work necessary to increase the surface by unit area.
Although not normally important, it can become so if the free surface is present
in a passage of small-diameter orifice or tube.
SURFACE TENSION
FLUIDS AT REST: HYDROSTATICS. For a fluid at rest, the force balance yields to:
Hydrostatic Equation
FLUIDS IN MOTION: At points along a horizontal streamline, higher pressure regions have lower fluid
speed and lower pressure regions have higher fluid speed.
The Bernoulli Equation
Used for measurements and flow
type determinations
The Reynolds Number
Reynolds for laminar flow
< 2000
Reynolds for turbulent flow
> 4000
Flow meters used for flow measurements in pipes containing steam. Used for flow testing purposes in production lines.
Orifice meter
Flow meters used in on-line installations. Used for flow measurement of gases.
Venturi meter
Flow meters used for flow measurements for a single point only.
Pitot tube
Flow meters used in bulk drugs and chemical industries. Used in fermentation systems for air control.
Rotameter
Valves used for isolation.
Gate Valve
Ball Valve
Diaphragm Valve
Valves used for control.
Globe Valve
Ball Valve
Butterfly Valve
Valves used for prevention of flow reversal.
Check Valve
Valves used for flow diversion.
Ball Valve
Plug Valve
Angle Valve
Pumps where energy is continuously applied to increase the fluid velocities
within the system.
Dynamic pumps
Pumps where energy is periodically applied unlike the dynamic pumps
Positive displacement pumps
Effective viscosity range of centrifugal versus positive displacement pumps
C: Efficiency decreases with increasing viscosity (max 200 cP)
PD: Efficiency increases with increasing viscosity
Pressure tolerance of centrifugal versus positive displacement pumps
C: Flow varies with changing pressure while efficiency decreases at both higher and lower pressures
PD: Flow insensitive to changing pressure but efficiency increases with increasing pressure