Article Contents
Different types of dryers
Different types of dryers are available in market like vacuum tray dryer, ANFD, Spray dryer, tray dryer , we need select suitable dryer as per our process requirement. We can study classification of dryers in details .
Drying is a process where we can dry the material by direct and indirect heating . In drying we can reduce the moisture as well as we decrease the LOD (Loss of drying).
what is drying ?
In simple words drying is mass transfer process which use to dry the material by removing moisture or other liquid from solid.
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Drying Process
Drying is mass transfer process in which we can remove the moisture or other liquid or solvent by applying heat , vacuum or using air . In drying we heat the material by applying steam or hot water .
Natural drying
In nature drying we dry the material using sunlight as source of heating , Or we can dry by atmospheric heat.
Example :- Drying of clothes in sunlight ⛅.
different types of dryers used in chemical industry
There are so many dryers available for drying , but mostly used dryers in chemical and pharmaceutical industries are as follows.
- Tray dryer
- Vacuum tray dryer
- ANFD
- Rotary cone vacuum dryer
- Spray dryer
- Fluideised bed dryer
- RVPD
Above are the main dryers used in chemical industry. Some dryers can play role of filtration as well as drying , like ANFD.
Tray dryer
Tray dryer is one of the simple dryer used in chemical industry. In tray dryer we load the material in to the tray. Then we put the trays in chember which has arrangement of heating.
In tray dryer we use only heating to dry the material. We need to take during heating to avoid any kind of fire hazard. We can provide small flow of nitrogen to avoid any kind of fire during drying of material.
Vacuum Tray dryer
In vacuum tray dryer we use vacuum as well as heating to dry the Material. In some as per material property we can remove the moisture by vacuum only ( i.e. without heating).
The main advantage of vacuum tray dryer is , we can dry the material at low temperatures due to use of vacuum. Some materials have property of getting decompose at higher temperature so use of vacuum tray dryer is very beneficial for such cases.
Fluidised Bed Dryer ( FBD )
Fluidised bed dryer is another mostly used dryer in pharmaceutical and chemical industry. This dryer is mostly used in pharmaceutical industry .
In Fluideised bed dryer we use hot air for drying purpose. To heat the air we can use hot water or steam as heating source. In Fluideised bed dryer (FBD) , we take the air from atmosphere using blower , then we heat the air as per required temperature . Then heated air is go to the bed of material , which Fluideised the material. In this way we dry the material in FBD.
In FBD we can dry the material which contains only moisture , if material have have tendancy to get fire then we can not use FBD.
If material have any issues of air then also we can not use FBD for drying.
Rotary Cone vacuum dryer ( RCVD)
Rotary Cone vacuum dryer (RCVD) contain a cone or container which rotat with a certain RPM.We feed the material in to the cone ,come has arrangement of vacuum and heating. For heating purpose we can use hot water or steam.
CONCULSION
Article clearly that drying is mass transfer process in which mass transfer take place from solid to vapour. There are different types of dryers used in chemical industry . Mostly used dryer are Rotary Cone vacuum dryer ( RCVD) , ANDF , vacuum tray dryer , FBD .
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