A Caloris customer was experiencing evaporator problems with their multiple-effect beverage concentration unit. The pressure relief valves would relieve on the preheater and the first-effect evaporator vessel. They also saw problems with the sump levels exceeding 100% during shutdown, and worried that the elevated levels were causing the vacuum pump to fault during startup.
Our engineer was booked for a three-day visit to troubleshoot the evaporator and provide operator training. He began with an inspection of the main evaporator vessels.
The tubes and distribution plates looked good and the main gaskets did not yet need replacing. He and the plant staff also inspected the lower sumps and all spray balls. They found one gasket in a vent line that was not installed correctly. They decided to replace all of the ferrule gaskets – most of which had not been replaced since the evaporator was installed (~6 years ago), and were now brittle. They also discovered a spray ball from one of the evaporator vessels had become lodged in the product outlet.
Upon removing the condenser lid and inspecting the cooling tower, our engineer found signs of scaling and recommended that plant staff implement effective cooling water treatment. Issues were identified with the cooling tower fill valve, and corrective adjustments made.
Additional maintenance issues were identified for the plant to follow up on at a later date, including maintenance for the vacuum pumps and un-clogging of de-superheat spray nozzles.
After the service visit, our engineer issued a report along with a list of maintenance recommendations. He also proposed remote monitoring so he could keep tabs on the system, as well as a sequence of periodic check-up visits to ensure that the evaporator returns to – and remains in – good working order.
Meet The Engineer

Key Takeaways
- The cooling tower and cooling tower water supply system are critical to the evaporator, and need to be kept healthy or the evaporator won’t perform.
- Evaporators require a preventative maintenance plan with planned intervals for things like replacing gaskets, rebuilding valves, replacing pump seals. These things will catch up with you over time.
Experiencing Evaporator Problems?
If you are seeking to optimize your evaporator, contact Caloris at 410-822-6900 or problem.solved@caloris.com to arrange for a process assessment at your facility.
