NOVEMBER 2016
| WORLD FERTILIZER |
119
74% with full damper control. Decay of the system
parameters will reduce during switchover from 79% to 85%
in flow rate and from 62% to 72% in pressure, as shown in
Figure 5 for high turbine speed set and low speed turbine set,
respectively.
Conclusion
For a fast switchover, acceleration time and delays in fault
detection time are critical aspects: both will be minimised to
reduce overall switchover time and machine capability to
restore process parameters in due time.
As stated, the acceleration time is dependent on fan inertia
and motor torque capability; fault detection is based on process
monitoring and the time response of the DCS/electrical system.
The operating logic can be tuned to the most appropriate
operating point, ensuring safe and reliable operation during
emergencies. This can be achieved by setting the normal
operating speed of the turbine and fan regulating damper
opening.
Required minimum switchover time is given by process to
avoid reformer trip and it is generally in the range 5 – 20 sec.,
depending on plant size. The overall switchover time is essential
to determine a reliable design to select a proper fan, motor and
turbine.
With experience dating from the 1980s, Boldrocchi has
developed considerable proficiency regarding plant
reliability.
91%
-15°
-30°
-45°
-60°
-75°
-85°
Rated
Normal
100%
0%
20%
40%
60%
80%
100%
120%
140%
0%
50%
100%
150%
200%
Pressure [%]
Flow Rate [%]
FLOW RATE - TOTAL PRESSURE
91%
0°
-15°
-30°
-45°
-60°
-75°
-85°
Rated
Normal
100%
0%
20%
40%
60%
80%
100%
120%
0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 200%
Power [%]
Flow Rate [%]
FLOW RATE - SHAFT POWER
Non operability
area
Figure 6.
Fan performance curves.
58 |
Arvos Group GmbH |
SCHMIDTSCHE SCHACK
IBC |
Atlas Copco
105 |
AUMUND Foerdertechnik
GmbH
45 |
Blasch Precision Ceramics
61 |
BORSIG Process Heat
Exchanger GmbH
64, 74 |
CRU Group
OFC,
97 |
Devco
68 |
DSH Systems
11 |
EcoPhos
85 |
ECS Catalyst
113 |
EMT Blending, Bagging &
Transport Equipment
13 |
Enersul
47 |
Everest Sciences
7 |
Haldor Topsoe
IFC |
John Zink Hamworthy
Combustion
25 |
Johnson Matthey Process
Technologies
82 |
Kimre
73 |
Linde AG
41 |
Ludman Industries
8, 9 |
Matrix Service Co.
91 |
MHI Compressor
International
51 |
Neelam Aqua & Speciality
Chem Ltd
63 |
OHL Gutermuth Industrial
Valves GmbH
OBC |
Pittsburg Corning
53 |
Quest Integrity
81 |
Rembe GmbH
2 |
Sandvik Process Systems
69 |
Solex Thermal Sciences
4 |
thyssenkrupp
17 |
Yokogawa
AD INDEX
