This process is useful for drying of liquid i solvents used for cleaning and or purification of a material. This type of drying is found in chemical industries including petroleum refineries, etc., where a material is used by a process stream then recycled, dried and returned.
An example is acetone liquid stream that is used to wash threads used in manufacture of tea bags. The dirty acetone leaves the washing tank, is purified by a carbon purification system and is then is distilled in the column. The column vaporizes the acetone removing most of the contamination, however the acetone will contain approx 2 % water. This wet acetone can be dried in a liquid dryer.
Another example is cyclohexane used for preparation of Polymer Suspension and Solution. If Cyclohexane is not dry, it may cause changes in viscosity, curing time and drying time of the ix, resulting in off-grade material.
Liquid drying system consists of molecular sieve based adsorption towers. This system eliminates the distillation process. Liquids like Ethyl Alcohol, Benzene, Toluene; and Acetone can be easily dried beyond azeotropic limits.
The moisture content can be reduced form 6% to 5 ppm. The final dryness will however depend upon the mode of regeneration employed. The regeneration can be done using Vacuum or closed circuit nitrogen circulation.
Liquid dryers, if used in batches, have a single adsorber and for continuous operation will have two adsorbers. The regeneration takes much longer than gas drying and may be done by heating the bed in closed loop or by passing hot Nitrogen gas. The regeneration gas is heated in a heater and passed through the adsorber where moisture is condensed in a cooler and separated in a moisture separator. Liquid dryers are generally operated in manual mode, as the automatic plants are expensive.
We also have an R & D unit at our works and can take up feasability studies if required.
Following are just some of the large nuber of liquids which can be dried :
|Methyl Ethyl Ketone||Xylene|
Following is the list of some Industries where such systems are useful:
|Agro chemicals||Magnetic tapes|
|Audio Tape||Paper and pulp|
|Brake Lining||Photo Film|
|Film coating||Typewriter ribbon|