Water Production

Question 1

Fresh Water Uses

Answer 1

• Drinking
• Washing
• Cooking
• Cleaning

Question 2

Services provided by Fresh Water System

Answer 2

The laundry

The galley

Showers and sinks

Water heaters

Medical use

Bridge window washers

Fresh water hose reals

Machinery cooling

Question 3

What is osmosis

Answer 3

Is the transfer of pure water through a semi-permeable membrane into salt water

Question 4

What is reverse osmosis

Answer 4

Is the transfer of water from salt water through a semi-permeable membrane into pure water

Question 5

What is TDS

Answer 5

Total Dissolved Solids - measure of water purity

Question 6

What is the TDS of sea water

Answer 6

34000ppm

Question 7

TDS of water after desalination

Answer 7

between 250 & 300ppm

Question 8

What percentage of sea water is ejected

Answer 8

Approximately 80%

Question 9

Desalination water is called

Answer 9

Permeate and sometimes referred to as made water

Question 10

Waste water after desalination is called

Answer 10

Concentrate

Question 11

Name the 2 filtration stages of the Reverse Osmosis Plant

Answer 11

Bag Filter
Cartridge filter

Question 12

Bag filters down to

Answer 12

60 microns

Question 13

Cartridge filters down to

Answer 13

10 microns

Question 14

High pressure, 3 piston positive displacement pump

Answer 14

Provides 65 bar

Question 15

What provides 65 bar to the Reverse Osmosis plant

Answer 15

The high pressure. 3 piston positive displacement pump

Question 16

Salt water to the….

Answer 16

Cushion membranes

Question 17

Cushion membranes have…..

Answer 17

Ultrasonically welded edges

Question 18

What does the anti scaling doping unit do?

Answer 18

prevents precipitation of calcium salts directly forming on the membrane surfaces.

Question 19

Name the anti sealant used, and the rate it is added at

Answer 19

Hypersperse, 5ppm

Question 20

What is CCV

Answer 20

Concentration Control Valve

Question 21

What does the CCV do?

Answer 21

This controls the Back Pressure of the sea water acting on the Membrane Cushions.

Question 22

How does CCV work?

Answer 22

By Closing the valve, the back pressure is Increased and the amount of Permeate is Increased. Therefore, Opening the valve Reduces the back pressure and the amount of Permeate is Reduced.

Question 23

Water passing through Reverse Osmosis Plant cannot contain….

Answer 23

Chlorine, as it can cause irreversible lasting damage to the membranes

Question 24

What is added to water to kill bacteria

Answer 24

Chlorine

Question 25

When are chlorine levels checked?

Answer 25

Daily and before Embarkation.

Question 26

What rate is chlorine maintained at?

Answer 26

0.2ppm

Question 27

When should desalination not continue?

Answer 27

if the source of water is likely to be contaminated. Harbour water and Estuary waters being prime examples.

Question 28

Who supervises the addition of water to the water?

Answer 28

Section Head

Question 29

Name the 3 water tests

Answer 29

1. CHEMets
2. Visual
3. Taste

Question 30

What are calorifiers for?

Answer 30

Heating the water on board

Question 31

Name a kind of Air Eliminator

Answer 31

Water Hammer

Question 32

What does the water hammer do?

Answer 32

a loud and repetitive banging noise inside the pipes

Question 33

How are fresh water hoses used?

Answer 33

Blue in colour – they should be flushed with fresh water before use

Question 34

Reverse Osmosis diagram

Answer 34

Reverse Osmosis Diagram

Question 35

How can scaling of membranes be prevented

Answer 35

Hypersperce, 5ppm