Seawater Desalination System for Seawater Purification Plant

 

Why have to desalinate sea water

Seawater desalination filters seawater into freshwater by filtration system to increase available freshwater resources. It is an open-source incremental technology for the utilization of water resources. The filtered water quality is good and the price is more reasonable.

Desalination of seawater ensures stable water supply for coastal residents and industrial boiler replenishment. It is mainly used to provide drinking water and agricultural water, edible salt is produced as a by-product. Desalination is popular in many countries and it is also used on certain islands and ships.

Different Seawater Desalination Systems

There are two main types of desalination processes: distillation method and membrane method. The low multiple-effect distillation method, multi-stage flash method and reverse osmosis (RO) membrane method are the mainstream technologies in the world. 

Generally speaking, the low multiple-effect distillation method has the advantages of energy saving, low seawater pretreatment requirements, and high desalinated water quality. The RO membrane method has the advantages of low investment and low energy consumption, but has high requirements for seawater pretreatment. The multi-stage flash evaporation method has the advantages of mature technology, reliable operation, and large output of the device, but the energy consumption is relatively high. It is generally believed that the low multiple-effect distillation method and the reverse osmosis membrane method are the future directions.

 

RO Seawater Desalination System

Reverse osmosis seawater desalination equipment is a device that uses the principle of reverse osmosis technology to desalinate seawater. The composition of the reverse osmosis marine water maker: water intake system, pretreatment system, seawater desalination system, energy recovery system, chemical cleaning system, chemical dosing system, and device power supply and distribution and automatic control system. The whole set of equipment consists of a pretreatment system, reverse osmosis system, electrical control system, cleaning system and dosing system.

The equipment of reverse osmosis seawater desalination machine is small in size and simple in installation. Easy operation and maintenance, no disassembly for cleaning and maintenance, and easy management. The equipment does not have high requirements on the inlet water temperature. As long as the seawater at any normal temperature between 5 °C and 45 °C can be used for desalination, and the marine equipment is generally equipped with low power, the main engine and auxiliary engine work.

 

Portable Desalination Systems

Portable desalination systems are ideal for solving water problems in remote areas such as rural areas. While many reverse osmosis-based portable desalination water purification systems are commercially available, they are insufficient to provide reliable drinking water in remote areas due to the need for high-pressure pumping and repeated maintenance. In response to this situation, a research team at the Massachusetts Institute of Technology has developed a portable desalination system that can be used to produce drinking water in remote areas.

The scientific research team demonstrated a field-deployable desalination system with a multi-stage electro membrane process, which consists of a two-stage ion concentration polarization system and a one-stage electrodialysis system, which can combine brackish water and Seawater is converted into drinking water. In experiments, the portable system desalinated brackish water and seawater into drinking water with energy consumption per liter of water per hour within 4 watts (brackish water) and 26 watts (seawater), respectively. In addition, the process can reduce the suspended solids in the water by 1/10, and even the water with high turbidity (i.e. turbid seawater caused by the tide) can produce clear water.