What is Distilled Water?
Distilled water is water which has been passed through a series of condensation and evaporation cycles (which can be as few as one and many as three) until the quantity of dissolved solids in the water is very low (typically less than 2 parts-per-million). Distilled water typically has a pH level of just under 7.
Based on the principal that the vast majority of minerals, metals, waste materials and bacteria found in water are heavier than the molecules of the water itself, the distillation process takes place when water is boiled in a distiller and the waste materials principally salts, calcium and other ions as well as possible up to two hundred and fifty forms of bacteria remain in situ while the pure water in the form of steam transfers to another clean vessel where it is allowed to cool off and return it's natural liquid state. Once this process has been completed the distilled water is tested for levels of purity.
The unit of purity is usualy PPM (Parts Per Millions) and represents to number of molecules of impurities dissolved in the pure water. Depending on the levels of contamination and the levels of pureness that need to be achieved, it is possible that the process will be repeated as many as three or four times until almost all impurities have been removed from the water.
Distilled water produced using this tried and trusted method will eventually contain an exceptionally high percentage of water molecules and an absolutely minimal presence of other gases, minerals, salts or contaminants. The principal reason why distilled water is produced is for industrial applications where water purity levels need to be very high.
Natural water is known to build up levels of minerals which can cause damage to machinery over a relatively short space of time. Whilst distilled water is that bit more expensive, in the long term, is a very good investment for industrial companies to use distilled water and save costly downtime. The process involved in distilling water can be quite lengthy and power intensive. However, in recent years advances have been made in the development of multi-effect evaporators that have been found to significantly reduce energy requirements over the traditional single evaporation units that have been in use since water distillation became common practice.
The multi-effect distillation process has been designed take considerable advantage of the laws of thermodynamics. By reducing the pressure in the condensation container the boiling temperature of water in the container will be considerably decreased using this method the heated water is introduced at considerably lower pressures. Consequently vaporising at a reduced temperature considerably reducing, energy required for heating.
Through using this method, water distillation can be more efficient due to increased levels of water evaporation whilst using the same levels of energy input.