Evaporator cleaning interval on a fresh water generator
The evaporator cleaning interval on M/V Hermes Leader’s fresh water generator was too short, as scale built up on the heat exchanger plates and water production dropped to around 17 cubic metres a day. Clearing the plates meant manual scraping that risked damaging them, and cleaning downtime needed to come down. In January 2015 an HM120 was fitted to the seawater inlet pipe to the generator. The cleaning interval then extended to 4,000 hours. When cleaning was done, deposits detached easily rather than needing to be scraped off, no chemical soaking was required, and water production recovered.
The Challenges
- The evaporator cleaning interval was too short as scale built up on FWG plates
- Water production had dropped to around 17 cubic metres a day
- Manual scraping risked damaging the plates
- Cleaning downtime needed to be reduced
- Output had to be restored without chemical soaking
The Solution
- Unit installed: One HM120
- Installation point: seawater inlet pipe to the fresh water generator
- Installed: January 2015
- Previous treatment: manual scraping of the heat exchanger plates
The HM120 was fitted to the seawater inlet, so all feed to the generator passes the unit before reaching the plates. The signal disrupts the conditions that bond scale to surfaces, so deposits detach easily at cleaning and the risk of plate damage drops. The generator then ran until the evaporator cleaning interval reached 4,000 hours, and water production recovered.
