Types Of Drying Systems Used In Various Industries
                     Types Of Drying Systems Used In Various 
Industries
Neel Rao
Writes on Reitz India forced draft fan & Reitz 
India Industrial centrifugal fans manufacturer.
Drying systems show a considerable variation, depending on the nature of the 
industry in which it is used. Firstly, you must be knowing that drying essentially 
differs from evaporation. Particularly food products need to be dehydrated using 
various methods. This application finds its use primarily in the food industry.
This includes milk and other dairy products, coffee surrogates, coffee, flavours, 
creamers, spices, herbs, vegetables and fruits. In some uses when correctly done, 
the process ensures that the shape of the food is retained. Further, drying also 
decreases the bulk weight of the products.
Different Types Of Drying Systems And Their Applications
Here are some of the common types of drying systems, that are used in various 
industries.
Fluidized Bed Dryers (Food & Pharma)
In this type of dryer, an air stream flowing upward is used to suspend the food 
materials against gravity. Besides, a horizontal air-flow is also used to make the food 
pass through the dryer. Therefore, the heat transfer takes place between air and the 
food material. Mostly, the transfer takes place through convection. The solid 
particles, that are fluidized, behave like liquids, and it is not possible to convey them. 
The velocity of air varies with the density and size of the particles. This process is 
effective during both drying and cooling processes.For pharmaceutical industry fan, 
static pressure is always on the higher side.This process is required for food and 
pharma both.
Spray Dryers
Here, the product to be dried has to be suspended in the air. The liquid is converted 
to a mist or fog-like material. In the drying chamber, the atomized liquid gets 
exposed to a heated air-flow in a drying chamber. The flow of solid materials and air 
may be in a counterflow or parallel direction. The evaporation of moisture takes 
place fast. This process is ideal for materials that get damaged due to their exposure 
to heat. The solid materials can be recovered in the form of a powder, that consists 
of hollow, fine and spherical particles.
Drying systems used in various industries largely depend on the nature of water 
content present. It may be vapour, water or ice. Other factors like humidity and 
cross-ventilation also come into the play. In order to lower the chance of bacterial 
growth, the items need to be dehydrated.This process is applicable for food process 
industries.In this process, Exhaust fan (ID Fan) and supply fan (FD Fan) is 
required.Exhaust fan needs to handle some dusts which is sticky in nature and 
corrosive also. That is why we need to take care about the blade profile of the 
impeller and material of construction. Stainless Steel is mainly used as a primary 
material of construction for both ID & FD application. We need to take utmost care 
about the inside surface finish of these fans because mostly these fans handle food 
product, milk powder etc.in this application exhaust fans need to have gas tight 
construction with sealing arrangement, machined flange etc. No spot welding is 
acceptable inside the casing. We need to adhere to full welding inside the casing. It 
needs to be smooth, uniform. No black marks and under cuts are acceptable. 
The static pressure in these type of fans is in the range of 1200 mmwg-1800 mmwg. 
The fans should be develop that much static pressure at a given volume 
requirement. In few cases fan handles fine dust particles and our impeller design is 
suitable for the same.
About REITZINDIA
Reitz India has set a benchmark to deliver high quality fans for heavy duty industries 
which can work at precise operating conditions like high temperatures and pressures. 
Reitz offer idealistic Centrifugal Fan and Centrifugal blower design that can be used in 
all large scale process industries like cement, iron & steel, power plants, fertilizers/ 
chemicals and more.
Thank you for spending your precious time in reading this article!