The Problem
Improperly managed tube wall temperatures can be extremely costly for the plant.
Tube Wall Temperature (Celsius) |
Tube Life |
860 |
10 years |
880 |
5 years |
900 |
2.5 years |
925 |
11 months |
950 |
4.5 months |
972 |
2 months |
1000 |
4 weeks |
1050 |
5.5 days |
1100 |
1 day |
As a rule of thumb, approximately every 20 degrees above the design temperature will half the tube life. A typical rebuild of a 400 tube reformer can easily go upwards of S$10M just for materials alone. Accounting for labour and lost of production, this amount can double.
As such, it is normal for producers to ensure that the Tube Wall Temperature is maintained in the safe zone, leading to lower production rates. Despite this, hot spots still do cause problems which can be hard to identify only with the use of handheld pyrometers by operators on a limited schedule.
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