Water Production Flashcards
What are some of the uses for Fresh Water?
-Drinking
-Washing
-Cooking
-Cleaning
What services are provided by the Fresh Water System?
-Laundry
-Galley
-Showers and Sinks
-Water Heaters
-Medical Use
-Bridge Window Washers
-Fresh Water Hose Reals
-Machinery Cooling
What is Osmosis?
The transfer of pure water through a semi-permeable membrane into salt water
What is Reverse Osmosis?
Transfer of salt water through a semi-permeable membrane into pure water
How is Water Purity measured?
Total Dissolved Solids (TDS)
What is the TDS of Sea Water?
Approximately 34,000ppm
What is the TDS of the water after desalination?
Between 250 and 300ppm
How much of the supplied Sea Water is ejected?
Approximately 80%
What is the desalinated water called?
Permeate, sometimes referred to as Made Water
What is the waste water called after desalination?
Concentrate
What filters do RO Plants use?
-Bag Filter
-Cartridge Filter
What do Bag Filters filter down to?
60 Microns
What do Cartridge Filters filter down to?
10 Microns
What pump does an RO Plant use?
High Pressure, 3 Piston Positive Displacement Pump
What is the pressure produced by the pump in an RO Plant?
65 Bar
What separates the Made Water from the Rejected Water in an RO Plant?
Cushioned Membranes that have ultrasonically welded edges
What does an Anti-Scalant Dosing Unit prevent?
Precipitation of calcium salts directly forming on the membrane surfaces
What rate is Hypersperce applied?
5ppm
What is the purpose of the Concentration Control Valve?
To control the back pressure of the sea water acting on the membrane cushions
How does the Concentration Control Valve work?
-By closing the valve, the back pressure is increased and the amount of permeate is increased
-By opening the valve, the back pressure is reduced and reduces the amount of permeate
Why can’t water contain Chlorine when is passes through an RO Plant?
It will cause irreversible damage to the membranes
When is Chlorine added to the water?
After the membranes, in order to kill off any bacteria
What is the maintained level of Chlorine in Made Water?
0.2ppm
When should desalination not continue?
If the source of water is likely to be contaminated
Who authorises the addition of Chlorine to the fresh water?
Section Head
When does Fresh Water Testing take place?
Daily and prior to embarkation
What are the different Fresh Water Tests?
-CHEMets
-Visual
-Taste
What are Calorifiers used for?
To heat water on-board ship
What is a symptom of air in the fresh water system?
‘Water Hammer’, which is a loud and repetitive banging noise inside the pipes
What colour are Fresh Water hoses?
Blue
What should you do before using a fresh water hose?
Flush it out with fresh water
