How does multi effect distillation work?
It consists of multiple stages or “effects”. In each stage the feed water is heated by steam in tubes, usually by spraying saline water onto them. Some of the water evaporates, and this steam flows into the tubes of the next stage (effect), heating and evaporating more water.
What is adsorption desalination?
Adsorption desalination (also known as AD) is a boiling point elevation and vapour pressure lowering desalination technique. Silica gel has a high affinity to adsorb water vapour. Since this is done in a closed environment, the pressure is lowered till boiling.
How does thermal desalination work?
Thermal desalination is a process that involves changing saline water into vapor. This vapor, or steam, is generally free of the salt, minerals, and other contaminants that were in the saline water. When condensed, this vapor forms a high-purity distilled water. A distiller produces distilled water.
What is the function of an end condenser in the MED plant?
The condenser is a simple heat exchanger which is used to condense the vapour produced, but also to preheat the feed brine before it enters the evaporator. This is the simplest distillation process, not very much used in the desalination industry, due to its low efficiency.
What are the disadvantages of multistage flash distillation?
Disadvantages of a multi-stage flash distillation system are a high operating cost when waste heat is not available for the distillation process and relatively high rates of corrosion and scale formation due to high operating temperatures.
What is multi effect and Vapour compression distillation?
Multi-Effect Distillation (MED) is a thermal desalination technology that produces distilled quality water directly from seawater by using low / medium pressure steam and electricity. With the use of a Thermo Vapour Compressor along with MED, the technology is named MED-TVC.
Is thermal desalination better than reverse osmosis?
Thermal Desalination VS Reverse Osmosis RO can remove many types of molecules and ions, making it suited for potable and industrial uses. Thermal desalination mimics the natural process of the water cycle – evaporation from the ocean, accumulation in the atmosphere, condensation as rain or snow, and collection.
What are 2 main methods of desalination?
Two distillation technologies are used primarily around the world for desalination: thermal distillation and membrane distillation.
How does multi-stage flash distillation work?
The multi-stage flash distillation is a process where incoming seawater is pumped to a higher pressure and heated to near boiling. Through a series of stages, the seawater pressure is decreased to generate vapor that is condensed by the incoming seawater.
What resources does multistage flash distillation require?
15.2. These processes include multi-stage flash (MSF) distillation, multi-effect distillation (MED) and vapor compression distillation (VC). Each of these processes require thermal or mechanical energy to cause water evaporation.
Why is multistage flash more expensive than reverse osmosis?
MSF plants are considerably larger than RO plants with special materials. Consequentially the construction and land costs are high. Since steam is used piping, condensate and other associated systems are involved. All these result in increased maintenance costs.
What are multiple effects?
: relating to or consisting of a series of evaporators in which the pressure decreases progressively from one to the next so that the vapor from each unit except the last heats the liquid in the next unit.