Biomedical Engineering Reference
In-Depth Information
Modules
Hollow Fiber-Capillary
Plate and Frame
Spiral Wound
•Very small diameter
membranes (< 1mm)
• Consist large number of
membranes in a module
and self supporting.
• Density is about 600 to
1200 m
2
/m
3
. (for
capillary membrane), up
to 30000 m
2
/m
3
. (hollow
fiber)
• Size is smaller than
other module for given
performance capacity.
• Process “inside-out”,
permeate is collected
outside of membrane
• Process “outside-in”,
• Structure is simple and
the membrane
• Is formed from a plate and frame
sheet wrapped around a center
collection pipe
• Density is about 300 to 1000 m
2
/m
3
.
• Its diameter can up to 40cm.
• Feed flows axial on cylindrical
module and permeate flow into the
central pipe.
• Features:
1. High pressure durability.
2. Compactness.
3. Low permeate pressure drop and
membrane contamination.
4. Minimum concentration
polarization.
replacement easy.
• Similar to filter press
• Density is about 100 to
400 m
2
/m
3
.
• Membranes is placed in a
sandwich style with feed
sides facing each other.
• Feed flows from its sides
and permeate comes out
from the top and the
bottom of the frame.
• Membranes are held apart
by a corrugated spacer.
permeate passes into
membrane bore.
• Ceramic membranes are usually
• Not self supporting and normally are inserted in
other materials' tubes with diameter more than
10mm.
• Density is not more than 300 m
2
/m
3
.
• Features:
1. Can operate with simple pre-treatment of feed liquid.
2. Membranes replacement is easy.
3. Easy to be washed.
monoliths of tubular capillaries.
• Channel sizes are in millimeter range.
• Becomes a module by attaching end
fittings and a means of permeate
collection.
• Many monoliths are usually incorporated
into one modular housing.
FIGURE 10.2
Membrane configuration.
However, it also has some disadvantages that contribute to its application
constraints. Among the disadvantages are
•
Membrane fouling
: Membrane fouling of hollow fiber is more fre-
quent than other membranes due to its configuration. Contaminated
feed will increase the rate of membrane fouling, especially for hol-
low fiber.
•
Expensive
: Hollow fiber is more expensive than other membranes
that are available in the market. It is because its fabrication method
and expense is higher than other membranes.
•
Lack of research
: Hollow fiber is a new technology and, so far, there
has been less research done on it compared to other types of mem-
branes. Hence, more research will be done on it in the future.
Hollow fiber made of polymer cannot be used on corrosive substances and in
high-temperature conditions. Various types of membrane processes can be
found in almost all of the literature references.
