Drum Dryers are extensively used in food industry for their function to dry the products in such a way that they do not lose the essential nutrients present in food products. one of its type i.e. single drum dryer is explained in detail.

1. SINGLE DRUM
TYPE DRYER
Maira Jabeen
L1F18BSFT0021

2. HISTORY
• John Augustus Just first invented drum dryers in United States.
• First introduced in early 1900s.
• Demand went high in 1940s and 1950s.
• Frequently used in 1960.

3. PRINCIPLE
Conduction
Evaporation

4. CONSTRUCTION
https://www.sciencedirect.com/topics/engineering/drum-drying
Range of diameter 0.5 to 6 m
Range of length 1 to 6 meters

5. WORKING MECHANISM
A hollow cylinder i.e. the drum is heated by
using steam
Temperature achieved for the cylinder is 120
to 155 degree centigrade
The product is then applied to the surface of
drum by dipping it in the feeding system.
After drying it is removed from drum surface
by the use of scrapper or blades.

6. TYPES
http://www.katsuragi.co.jp/en/products/01/drumdryer.html
Splash
feed
type
Top
feed
type
Dip
feed
type
Multi
roll
feed
type
Below
feed
type
Side
roll
feed
type

7. Dip feed type Splash feed type Top feed type
Below feed type Side roll feed type Multi roll feed type
http://www.katsuragi.co.jp/en/products/01/drumdryer.html

8. APPLICATION
This type of drum dryer is frequently employed in the production of:
 Soup mixtures
 Milk powder
 Baby Foods
 Mashed potatoes
 Breakfast cereals
 Fruit and Vegetable pulp etc.
https://drumdryingresources.com/ddr/drum_dryers/drum-drying-it

9. ADVANTAGES
• It is easy to operate.
• It maintains the porosity of the food product.
• Most energy efficient method.
• It is used for foods that cannot be processed in any other method.
• Suitable for small quantity production.
• Easy to clean.
http://sites.bsyse.wsu.edu/tang/main/publications/pdfdocs/book-drumdry-tang03.pdf

10. DISADVANTAGES
• Some substances are difficult to remove.
• High cost of maintenance.
• It is not suitable for the processing of high salty foods.
• Some products may loose their flavor.
http://sites.bsyse.wsu.edu/tang/main/publications/pdfdocs/book-drumdry-tang03.pdf

11. PINPOINT
It is very important to achieve a delicate balance between the:
 Feeding rate
 Rolling speed of the drum
 Thickness of the material
 Pressure of steam.
Evenly applied substance gives evenly dried product.
http://sites.bsyse.wsu.edu/tang/main/publications/pdfdocs/book-drumdry-tang03.pdf

12. COOLING MECHANISM
• Some products such as tomato puree are difficult to remove.
• It has high thermoplasticity property.
• A jet of cold air is applied before the product reaches to scrapper.
• This makes the removal of product easy.
http://sites.bsyse.wsu.edu/tang/main/publications/pdfdocs/book-drumdry-tang03.pdf