A Caloris customer was seeing rapid fouling on one of two identical evaporators, while its twin was able to operate effectively as designed. We sent an engineer to site to investigate the issue.
The problematic evaporator was fouling out within 5 hours of startup following a CIP cleaning, while the other evaporator could operate continuously for the designed run time between CIP cleanings. Plant staff revealed one of the CIP lines at the top of the problem evaporator was plugged with soil. They also found multiple spray balls filled with soil.
Our engineer asked if any event had occurred that may be the cause of all of the soil inside the unit. Plant staff said that the compressed air equipment had failed recently, which caused one the evaporators to flood with product. The HMI readings and conversations with plant staff showed that some aspects of the equipment were not running to spec since that incident.
An initial inspection of the evaporator revealed a vacuum leak on the spray condenser. Air could be heard being pulled in around the gasket. The gaskets were replaced the next day and the vacuum leak disappeared.
Next, the evaporator was thoroughly inspected for fouling, which was found in numerous places including the distribution pan and in plugged tubes. The inspection also showed that some of the calandria spray balls were not installed correctly, which was remedied.
A CIP run showed a lot of material flushed out of the system during both the caustic and acid washes. The calandria was inspected again, but there was still soil on top of the distribution pan. One of the valves was found to be malfunctioning and was replaced.
The next CIP run was scheduled for the evening shift and our engineer arrived at 9 p.m. to observe the last few hours of the CIP run and subsequent product run. The unit still wasn’t performing to spec, despite extending some of the wash times during the CIP run. Opening up the unit revealed more fouling and plugged tubes.
Our engineer recommended a water blasting of the unit to mechanically clean the remaining soil as the chemical washes were not strong enough. He also advised running longer washes during the standard CIP runs to ensure the chemicals had time to work and thoroughly clean the unit between product runs.
Checking the top and bottom of the tubes on a monthly basis was also recommended, to ensure that the unit was being cleaned sufficiently. Keeping tabs weekly on the solids levels from each pass would also reveal any potential issues.
Finally, our engineer noticed that plant staff were not starting up the equipment in a consistent manner. He recommended establishing and following standard operating procedures.
After the customer instituted the recommended changes, they reported to Caloris that they were seeing a huge difference in the operation of the machine.
If your processing equipment is no longer performing to spec or you are noticing fouling issues, contact us for an evaluation. Call us at 410-822-6900
to arrange a process assessment at your facility.