During product drying, lumps should be broken into smaller pieces. This improves the drying rate while reducing the heat requirement.
Drying is a process which is common to most process industries, be it drying of products in pharmaceutical and food industries.
Drying rate depends on major 3 factors –
- The temperature gradient
- The humidity in the environment
- The drying surface area
The first two remaining constant, the smaller the size of the material to be dried, the larger is the over all surface area that is available for drying. This is along the basic principles where the rate of reaction depends on the available surface area.
Often in it seen that the material to be dried is sent to the drier in huge lumps. This practice reduces the available surface area for drying. Thereby in case of products, increased amount of heat is required to achieve the desired moisture percentage. This increases the steam consumption. Thus wherever possible breaking the product into smaller pieces improves drying and reduces steam consumption.
The material is loaded and dried for a few hours to convert liquid to lumps. These are then taken out crushed and sent again to the drier. This practice reduces the steam consumption greatly.
In continuous driers it is observed that feed when sent in noodle shape (cylindrical) delivers the best results.
During our work with auditing and improving the steam systems of industries, we have observed the following good practices: