GEA Aircooled Systems

GEA Aircooled Systems
engineering for a better world
GEA Heat Exchangers
The HX-Factor, your additional value: combined
expertise and excellence in heat transfer
Efficiency and sustainability are standards. But GEA Heat Exchangers
(abbreviated “HX”, which stands for heat exchange) offer you more.
Because we have the HX-Factor. At HX, we all have it. Every team.
Every colleague. It can be found in all products and services. It makes
the difference. It assures you of added value in heat exchange.
By engineering services based on market experience and expertise.
By a sensitivity that leads to the right decision, even in the most
complex projects. By reliability in all situations. By the enjoyment of
difficult challenges. By commitment, far-sightedness, and precision.
All that is our HX-Factor. Experience it. Use it.
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GEA Aircooled Systems
The GEA parent company was founded by Mr. Otto Happel senior at Bochum, Germany.
Initially the company specialised in the manufacture of dust removal systems. Its name:
Gesellschaft fur Entstaubungs-Anlagen (company for dust-removal-plants), from which
the abbreviation GEA was derived.
Over the years the company’s activities expanded into fields of thermal and energy
technologies, food and process engineering, air-treatment, refrigeration and environmental
technology. GEA developed and pioneered the direct air-cooled steam condensation system
and became the world leader in this field, as well as in the design and manufacture of
finned tube heat transfer equipment. To supplement and complete this specialised
engineering and product range, an evaporative cooling tower division was established.
In 1971, GEA founded its South African company, GEA Aircooled Systems. Initially, GEA
Aircooled Systems functioned as an engineering and sales office for the group’s products
and services, which were essentially imported from the parent company. Large contracts
for the power industry were awarded to GEA Aircooled Systems in the early 1970’s, and
further contracts for the petro-chemical industry, resulting in a rapid expansion of the
South African operation. This necessitated the acquisition and subsequent extension of
local manufacturing facilities.
A total technology transfer from the parent company to GEA Aircooled Systems has been
effected and successfully implemented, rendering GEA Aircooled Systems largely
independent. GEA Aircooled Systems has become an integral part of GEA Heat
Exchangers, with substantial thermodynamic and mechanical design expertise, as well
GEA Group headquarters,
Düsseldorf, Germany
as engineering, manufacturing and contract management capabilities. Nonetheless,
GEA Aircooled Systems has access to all the resources and know-how of the GEA Group.
GEA Aircooled Systems’ service department evolved into a separate company, GEA
Nilenca, which specialises in refurbishment of heat transfer equipment, site erection work,
cleaning of heat exchangers, etc.
GEA Aircooled Systems, Roodekop,
South Africa
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Engineering and Quality
GEA Aircooled Systems is well
acquainted and experienced in the
design and manufacturing of the
following codes and guidelines:
The Quality Management System of GEA Aircooled Systems has been assessed and complies
with the requirements of BS EN ISO-9001 for design, manufacturing, supply, delivery, erection
and commissioning of heat exchanger plant and equipment.
ASME VIII
PD 5500
AD-2000 (AD Merkblätter)
TEMA
API 660
API 661
GEA Aircooled Systems relies on the most advanced computer equipment and software for:
Thermal design
Mechanical design
Preparation of the general outline drawings / fan selection and noise level prediction
Cost price estimation
Computational Fluid Dynamics (CFD) modelling
Finite Element Analysis (FEA)
Vibration analysis for shell-and-tube heat exchangers
The following thermal and mechanical engineering design software is available in-house and
is constantly upgraded:
Thermal design software:
HTRI, Heat Transfer Research Inc. (USA), for the thermal design of all types of shell-andtube heat exchangers as well as air-cooled heat exchangers.
GEA’s in-house heat exchanger and cooling tower design software.
Mechanical design software:
OPTIVESSEL – ASME VIII + PD5500 (SA)
COMPRESS – ASME VIII (USA)
FINGLOW – ASME VIII + PD5500 (UK)
Our in-house drawing office facilities employ state-of-the-art computer technologies, using
the latest AutoCAD and Autodesk Inventor draughting software.
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Research and Development
GEA is committed to ongoing research activities and programmes to provide its clients
with state-of-the-art products. In a competitive market where emphasis is placed on
environmental aspects and management of resources, continuous research is required to
ensure technically and economically optimised engineering solutions.
GEA has an in-house research and development department at its headquarters in
Germany, dedicated to the technological development of heat exchanger products offered
by the GEA group of companies. Research techniques applied by GEA include theoretical
analysis, experimental investigations and Computational Fluid Dynamics (CFD).
Model tests in wind tunnels and CFD modelling are used to determine the operating
characteristics of cooling systems in the vicinity of buildings and structures, as well as the
effect of wind on the cooling system’s performance. Examples include thermal and
fluid-dynamic analysis of column-top air-cooled condensers for petro-chemical plants,
evaporative cooling systems and dry cooling systems for power stations.
Investigations into the performance of axial flow fans and the air-flow distribution in
cooling systems assist us in the accurate prediction of their performance. Where possible,
full scale models are constructed. Fans of up to 10 m in diameter can be installed in a test
rig to investigate the air-flow through the heat exchanger configuration.
Droplet impact on a T-shaped slat at
5 millisecond intervals
In South Africa, GEA co-operates with universities and engineering consultants to investigate
and improve the performance of our product range. This enables us to offer customised
cooling systems on request. Such investigations not only constitute advances for GEA but
also assist our clients in gaining a better understanding of the products being procured.
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BEE
GEA Aircooled Systems is a proud contributor to South Africa’s BBBEE (Broad Based
Black Economic Empowerment) program. The current shareholders of GEA Aircooled
Systems are GEA TE, Nozala Investments, Tanguliza Services, Komec Investments and
an employee share scheme (ESOP).
GEA Aircooled Systems currently qualifies as a DTI Level 3 contributor and has
qualified as a BEE (Black Economic Empowerment) supplier in line with the
requirements of ESKADAAT 6 Revision 4.
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In-house facilities
The GEA Aircooled Systems manufacturing operation is split into two distinct areas of
manufacture.
The Standard Products shop caters for the manufacture, repair and reconditioning of
shell-and-tube heat exchangers as well as air-cooled heat exchangers, pressure vessels and
distillation columns for the petro-chemical, mining and power industries. These products
are manufactured in carbon steel, stainless steel and various exotic materials. A designated
clean area for the manufacture of feedwater heaters – using the latest technology for
internal bore welding of tubes to tubesheets – is in place.
Plate rolling machine
The second manufacturing area is used to manufacture specialised galvanised air-cooled
condenser bundles for direct steam condensing systems for the local and export markets.
Undercover manufacturing area – 14 863 m2
Total plot area – 21 518 m2
Maximum crane capacity – 70 t
Hydraulic plate rolls with capacities up to 110 mm thick x 3 000 mm wide
CNC profile cutting up to 250 mm thick
CNC plasma profile cutting up to 160 mm thick
2 x Quickmill CNC drilling machines – 3 m x 6 m
Numerically controlled drilling
Kiheung CNC milling machine – 1.5 m x 4 m
Niles Vernon boring mill – 2.8 m diameter
3 x McElroy finning machines for spirally wound and embedded finned tubing
6 x Edelhoff finning machines for hot dip galvanized finned tubing
2 x DEMAG overhead cranes – Capacity: 35 t each, total 70 t
7 x DEMAG overhead cranes – Capacity: 8 t to 12.5 t each
1 x overhead crane double hoist – Capacity: 2 x 6.3 t (galvanising plant)
1 x DEMAG overhead crane – Capacity: 25 t
McElroy finning machine
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Products and services
GEA offers customised solutions – quality products and services especially
tailored to meet your specific needs in the following categories:
• Air-cooled heat exchangers for any application
• Finned tube heat exchangers such as oxygen coolers and compressor
intercoolers
• A large variety of finned tubes
• Direct air-cooled condensers for steam turbines
• Indirect condensing systems for steam turbines
• Shell-and-tube heat exchangers including recuperators, waste-heat boilers,
feedwater heaters and surface condensers
• Distillation columns
• Pressure vessels
• Cooling towers (mechanical and natural draft)
• Bulk air coolers
• Performance testing of heat exchangers and cooling towers
• In-house engineering and design including optimisation and lifecycle
costing
• Site services, installation, commissioning and shut-down services
• Refurbishment of heat exchangers and cooling towers
Our products are backed by the following commitment:
• High quality standards and products
• Design and engineering innovation
• On-time manufacturing
• Excellence in customer service
• Professionalism and ethical business practice
• Proficient management
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Finned tubes
GEA manufacture various types of aluminium, copper, stainless steel and galvanized carbon
steel finned tubes, according to the customer specifications for working temperatures,
ambient temperatures, corrosive atmospheres, etc.
Finned tubes
FINNED TUBE TYPES AND THEIR APPLICATION
Bi-metallic
extruded
Embedded
“G”
Wrap-on
“L”
Wrap-on
double “L”
Hot-dip
galvanised
Maximum working
temperature
350°C
400°C
130°C
130°C
400°C
Maximum working
temperature according to
API 661 6th Edition 2006
300°C
400°C
130°C
130°C
360°C
Atmospheric corrosion
resistance
Excellent
Poor
Acceptable
Medium
Excellent
Mechanical resistance
Excellent
Poor
Acceptable
Medium
Excellent
Fin material
Aluminium
Aluminium /
Copper /
Stainless steel
Copper /
Aluminium
Copper /
Aluminium
Steel
Tube material
Any metallic
material
Any readily
machinable
material
Any metallic
material
Any metallic
material
Steel
High efficiency
fin with complete
protection of base
tube against
corrosion
High efficiency
fin for high
temperature
application
Standard fin for
low temperature
with some corrosion
protection of base
tube
As for “L” fin
with better
corrosion
protection
for base tube
Excellent thermal
performance
with complete
corrosion
resistance
Image
Application
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Air-cooled heat exchangers
GEA offers a range of different air-cooled heat exchanger configurations in order to meet
the specific requirements of both the process and the site location. Whatever the
configuration, one of the most important design criteria is to ensure that air is allowed to
freely enter and leave the system, ensuring maximised heat transfer.
Induced draft air-cooled heat exchanger
Forced draft layout
Induced draft layout
Better access for maintenance to
Protection of finned surface against
fans and fan drive systems. Fans
wind, hail, snow and rain. Fan/
operate in a cold ambient air
plenum chamber configuration
stream.
ensures better air distribution and
less hot air recirculation.
Plug type header box
D-type header
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Plug type header
Removable cover plate header
Fan blades are generally made of either aluminium or Glass Reinforced Plastic (GRP).
Fan drive systems include conventional v-belts, integral v-belts, toothed High Torque Drive
(HTD) belts and gear drives linked to electric motors. Air-flow control can be realised
using variable pitch fans, variable louvres or Variable Speed Electric Drives (VSD).
Pressure distribution on the blades of a fan in an air-cooled heat exchanger
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Shell-and-tube heat exchangers
As technologies of the various process industries advance, they tend to use larger, more
sophisticated heat exchangers with improved performance.
The combination of technical advances in the fields of welding, heat treatment, and
non-destructive testing – with highly flexible manufacturing capabilities – allows GEA to
fully meet clients’ requirements, at the same time offering optimised solutions.
Shell-and-tube heat exchangers
GEA has the in-house capability to design and manufacture shell-and-tube heat
exchangers for the petrochemical, mining and power generation industries.
Large shell-and-tube heat exchanger with
removable bundle
HP and LP feedwater heaters
GEA Aircooled Systems has collaboration agreements with TEI (USA) and EON
(Germany) for the design and manufacture of feedwater heaters. Tubesheet type
feedwater heaters are offered. Tube to tubesheet attachments could be by conventional
welding, internal bore welding, explosion welding, etc.
Surface condensers
A surface condenser is the commonly used term for a water-cooled shell- and-tube heat
exchanger, installed on the exhaust steam side of a steam turbine. GEA supplies surface
condensers for vacuum condensing applications.
HP heater
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SHELL-AND-TUBE HEAT EXCHANGER TYPES
Front end Stationary
Head Types
A
Channel and
removable cover
Shell types
E
One pass
shell
F
B
Bonnet integral
covers
Two pass
shell with
longitudinal
baffle
G
Split flow
Rear end head types
L
Fixed
tubesheet
like “A”
stationary head
M
Fixed
tubesheet
like “B”
stationary head
N
Fixed
tubesheet
like “N”
stationary head
P
C
Channel
integral with
tubesheet and
removable
cover
(removable
tube cover only)
N
Channel
integral with
tubesheet and
removable
cover
H
Double split
flow
Surface condenser for vacuum steam
condensation
S
J
Divided
flow
Floating
head with
backing device
T
K
Kettle type
reboiler
Pull through
floating
head
U
U-tube
bundle
D
Special high
pressure closure
Outside
packed
floating head
X
Cross
flow
W
Externally
sealed
floating
tubesheet
Waste heat boiler for a petrochemical plant
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Air cooled condensers (ACC)
The GEA air-cooled condenser consists of finned tube bundles grouped together into fan
modules and mounted in an A-frame configuration on a concrete or steel support structure.
Fans mounted below the A-frames draw in air from below and force it through the finned
tube bundles.
Matimba ACC during construction
The steam side of an air cooled condenser operates as follows: steam from the steam turbine
enters the finned tube bundles from the top of the A-frames. The largest fraction of the
steam is condensed in the parallel flow modules (condenser) and the remaining steam is
ducted to the lower headers of the counterflow finned tube bundles (dephlegmator).
The steam enters the counterflow finned tube bundles from below and rises in the finned
tubes to a point where the condensation is complete. Non-condensable gasses are drawn
off above this point by vacuum equipment. The condensate drains to a condensate tank by
gravity and is then piped back to the feedwater system.
Elgen power station at BHP Billiton’s
Samancor plant
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Windwall
Majuba ACC
Counterflow module
Parallel flow module
Forced draft fan
Steam in
Air removal system
Condensate tank
Medupi ACC during construction
(Feb 2012) with Matimba Power Station
in the background
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Other heat exchangers & pressure vessels
Plate and frame heat exchangers
GEA offers its clients the following diverse range of plate heat exchanger systems:
Gasketed plate heat exchangers: A whole range of different plate types are used for cooling
and heating liquids and for condensing vapours. Special designs are also available for
evaporators and for liquids containing a high proportion of undissolved solid matter.
Brazed plate heat exchangers: These compact units consist of profiled stainless steel plates,
which are brazed together in a high vacuum furnace. Used in high pressure and/or high
Plate and frame heat exchangers
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temperature applications, or where gaskets are prone to chemical attack.
Plate and shell heat exchangers
GEA also offer plate and shell heat exchangers. These heat exchangers employ a welded
plate pack inside a shell. This type of design offers the high heat transfer rate of plate
and frame heat exchangers without the pressure limitations of the plate and frame heat
exchanger designs.
Inter/After coolers
All types of finned tubes for compressor inter- and after-coolers are produced at GEA
Aircooled Systems’ factory in Roodekop, Germiston.
Plate and shell heat exchanger
The inter- / after-coolers are typically manufactured using Cu-Ni tubes with Cu fins and
Cu-Ni tubesheets because of the water vapour condensing on the air side of these devices.
Oxygen coolers
GEA Aircooled Systems has been granted a provisional patent for the manufacturing process
of copper finned tubes suitable for 100% oxygen duty.
Pressure vessels and columns
GEA has the in-house capabilities to design and manufacture pressure vessels as well as
distillation columns. The petrochemical industry is a major client for this type of
Oxygen cooler
equipment.
Typical column in the workshop
Operating principle
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Cooling towers and BACs
Cooling systems utilising water evaporation are usually the most cost effective heat
rejection systems. In a cooling tower, hot water from a plant is brought into contact with
ambient air. Energy is transferred from the water to the air by evaporation (mass transfer)
and convection (heat transfer). The cooled water is then returned to the plant. Evaporative
cooling systems can achieve lower re-cooled water temperatures than dry cooling systems.
On-line refurbishment of natural draught
cooling tower
Evaporation rates are approximately 1.5 to 2 m3/hr per MW of heat rejection or 1% to 2%
of the circulating water flow rate.
In a natural draught cooling tower, the natural buoyancy of the hot air moves the air upwards through the tower, drawing in fresh cool air through the air inlet at ground level.
Therefore no fan is required. The tower shell is usually constructed in reinforced concrete
and can be as high as 200 m.
Belle Vue Power Station –
mechanical draught cooling towers
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Mechanical draught cooling towers on the other hand, make use of fans to generate the
air flow through the tower. Depending on the cooling load, multiple cells, each with its
own fan, can be employed. Fan diameters of up to 10 m and more are commonly used.
The relative flow direction of the water and the air streams can be arranged in either cross
or counterflow.
Bulk Air Coolers (BACs) are often employed to provide large quantities of cold air in mines.
A BAC is functionally an inverted cooling tower, in which cold water from a refrigeration
unit is used to cool the incoming air and to provide a stream of cold air into the mine.
Typical bulk air cooler
MAXIMUM COOLING WATER TSS (Total Suspended Solids)
Cross fluted
film fill
Vertical fluted
film fill
Trickle
type fill
Splash fill
Max TSS (continuous), ppm
70
120
300
No limitation
Max TSS (short term, <10 hrs), ppm
100
200
500
No limitation
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Excellence
Passion
Integrity
Responsibility
GEA-versity
GEA Heat Exchangers
GEA Aircooled Systems (Pty) Ltd
GEA Nilenca (Pty) Ltd
Aberdein St, Roodekop, Germiston, South Africa
Phone: +27 (0)11 861 1500, Fax: +27 (0)11 865 2200
gas@gea.com, www.gea.co.za
Aberdein St, Roodekop, Germiston, South Africa
Phone: +27 (0)11 866 4000, Fax: +27 (0)11 866 4040
gnl@gea.com, www.geanilenca.co.za
© GEA Heat Exchangers. All rights reserved.
GEA Group is a global engineering company with multi-billion euro sales and operations in more
than 50 countries. Founded in 1881, the company is one of the largest providers of innovative
equipment and process technology. GEA Group is listed in the STOXX® Europe 600 Index.