Heat exchanger
type
| Maximum pressure
| Temperature
range
| Fluid limitation
| Normal size
ranges for
individual unit | Special features
|
| Air-cooled | High on
process side
(500 bar). | High
temperature
possible on
process side (up
to 600°C). | Subject only to
material of
construction. | 5 to 350 m2
(bare tube) (per
bundle multiple
bundles often
used). | Heat rejection system. Requires fans.
Tubes normally finned. |
| Shell-and-tube | 300 bar
(shell).
1400 bar
(tube). | 25 to 600°C
(lower and
higher with
special
materials). | Subject only to
materials of
construction. | 10 to 1000 m2
(per shell
multiple shells
can be used). | Very adaptable and can be used for nearly all applications. |
| Brazed-plate | 16 bar | Up to 200°C. | Suitable for liquids
compatible with braze
material. | 1 to 10 m2 . | Modular construction.not easily
cleaned. |
Double-pipe
(plain and
finned tubes) | 300 bar
(shell)
(higher
pressures
possible with
special
design).
1400 bar
(tube). | 100 to
600°C (higher
with special
materials). | Subject only to
materials of
construction. | 0.25 to 200 m2
per unit multiple
units are often
used. | High thermal efficiency, standard
modular construction. |
Electric
tubular
heat
exchangers | 300 bar | Up to 700°C. | Subject only to materials of construction. | 3 to 650 kW.
Multiple units
used for larger
capacity. | Special control systems can be used to minimise impact on electrical supply. |
| Glass-tube | c. 1 bar | Up to 250°C. | Low pressure,
suitable for corrosive
fluids. | | Stainless steel often used in structure. |
| Graphite | 20 bar | 50°C to
165°C. | Corrosion resistant unless fluid attacks
resin. | 0.2 to 60 m2. | High corrosion resistance. |
| Spiral | 18 bar | Up to 400°C | Subject only to materials of construction.
Often used for
fouling duties. | Up to 200 m2. | High heat transfer efficiency.
Cylindrical geometry useful as
integral part of distillation tower. |
| Heat-pipe | Near
atmospheric. | <200°C
(higher with
special heat pipe
fluids). | Low pressure gases. | 100 to 1000 m2. | Near counter-flow operation
possible.
Extended surface possible on both sides. |
| Plastic tube | 1 bar | Up to 100°C. | Low pressure,suitable for corrosive
fluids. | | Stainless steel often used in
structure. |
| Plate-and-frame | 25 bar with
some models
up to 40 bar. | 25 to 175°C (
40 to 200°C
possible for very
special types) | Normally
unsuitable for
gases.
Limitation is
on gaskets. | 1 to 2500 m2 | Modular construction.
Normally the most economical if
applicable. |
| Plate-fin | 100 bar
(aluminium).
200 bar
(stainless
steel), | 273 to +
150°C
(aluminium)
(up to 600°C
in stainless
steel), | Low fouling. | <9 m volume | Very small AT possible.
Incorporation of multiple streams.
Very large surface area per unit
volume. |
| Printed-circuit | 1000 bar | 800°C (with
stainless steel
materiallimited). | Low fouling. | to 1000 m2 | Very large surface area per unit
volume. Stainless steel or higher
alloys normal construction
material. |
Rotary
regenerators | Near
atmospheric, | Up to 980°C. | Low pressured
gases. | | Inter-stream leakage must be
tolerated |
| Scraped- surface | 10 bar. | Up to 300°C. | Liquids subject only to
materials of
construction. | 5 to 10 m
height,
0.5 m dia. | Suitable for viscous and
crystallisation systems |
| Welded-plate | 60 bar (higher
in shells). | In excess of
65 0°C. | Subject only to materials of construction.
Not suitable for fouling
duties. | > 1000 m2 | Differential pressure should be less than 30 bar. Differential expansion should be borne in mind. |
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