Heat Exchangers: Design, Operation ... - 123SeminarsOnly

106 9 Troubleshooting
9 Troubleshooting
9.1 Heat exchangers’ problems
Heat transfer equipment provides the economic and process viability for many plant operations.
The basis for successful application of such equipment depends on the designer.
The problem that should be anticipated by the design to avoid high maintenance or
cleaning and costly shut down production include:
1. Fouling
2. Leakage
3. Corrosion
To anticipate maintenance problems the designer should need to be familiar with the
plant location, process flow sheet, plant operation. Some of the questions that must be
considered are:
1. will the heat exchanger need cleaning? how often? what cleaning method will be
used?
2. what penalty will the plant pay for leakages between the tubeside and shell side?
3. what kind of production upsets can occur that could affect the heat exchanger?will
cycling occur?
4. how will heat exchanger be started up and shut down?
5. will the heat exchanger be likely to require repairs? if so, will the repairs present
any special problem?
9.2 Fouling
9.2.1 Costs of fouling
• Increased maintenance costs
• Over-sizing and/or redundant (stand-by)equipment
• Special materials and/or design considerations
• Added cost of cleaning equipment ,chemicals
• Hazardous cleaning solution disposal
• Reduced service life and added energy costs
• Increased costs of environmental regulations
• Loss of plant capacity and/or efficiency Loss of waste heat recovery options
Dr. Ali A. Rabah, Dept of Chemeng, U of K, Email : rabahss@hotamil.com