Seawater Desalination Plants Operating Instructions

Abstract

The seawater desalination system take sea water as feed water. After treatment, it can be domestic water for people, and the conductivity would be less than 700?S/cm.

Process Chart

1. Operation principal

The feed sea water flow into multi-media filter firstly, containing refining quartz sand, and it can remove sand twigs, seaweed, colloid and other particles from the seawater. Secondly, the water flow into 5?m security filter and 1?m security filter, these two grade security filter can avoid the particles and impurities enter into RO system which over 1?m. Thirdly, the water will flow into reverse osmosis system through being pressurized up to 3.5~6.5 MPa by the high pressure pump , and then the reverse osmosis water enter into fresh water tank.

The system working by manual operation with automatic mode. It can continuously work to supply water, and automatic monitoring of water quality, automatic cleaning RO system. You can enjoy it simple operation, stable working and safety.

2. Working conditions

a. Permeate Capacity: ?10 T/D ( When seawater temperature is 25 ?)
Attention: The water production would change by water temperature, generally, production water would drop 3% when the temperature drop 1?.

b. Water production conductivity: ?700us/cm?25??

c. Power: 4.75 KW

d. Feed water requirements:

• Pollution Index: <5
• Turbidity degree: 0.5NTU
• Temperature: 5~40?
• ph: 5~8
• Free chlorine: <0.1mg/L
• Pressure: 0.1-0.4MPa

e. Operating Voltage: 380 V

3. Instructions

Start up

• Before starting the system, please make sure all valves at right position, and power and water supply normally.
• Take all control switches turn to automatic position ( If feed sea water pressure >0.3MPa, raw water pump could not start up).
• After starting up raw water pump and high pressure pump feed water pressure up to 0.2MPa, the low pressure controller will be closed. Then the high pressure pump automatic start up, after 1 minute, adjust reverse osmosis concentrated water regulating valve.( Generally, we do not need change it if the system can normally working after debugging.). Make working pressure between 3.5~6.5 MPa and water production 420L/H (25?).
• If any abnormal situation occur when the system is working, restart in the order (1)(2)(3) after the problem working out.
• The system have settled pressure protection and high pressure pump feed water pressure protection.

 Shut down

• Normal shutdown: Firstly, turn off the power of high pressure pump, the raw water pump would go on flushing reverse osmosis membrane about 30 seconds with low pressure. Secondly, turn off the power of raw water pump. Lastly, turn off power switch and feed water valve.
• Abnormal shutdown: Directly turn off power switch, and then the reverse osmosis system stop immediately. It would injury RO membrane and high pressure pump, and influence the working life, badly, it maybe result to directly damage! So, operator should avoid the system shutdown by turn off power directly.