Steam tube dryers
Metso's steam tube dryers represent indirect dryers, using steam as the heating mechanism.
The tubes are inside the kiln shell and move through the material. The heat transfer efficiency is thus very high.
The steam tube dryers are widely used in the food industry where the purity of the product is very important. They are also used in some mineral processing applications where low-pressure waste steam is available.
Rotary dryers are suitable for:
Main benefits of Metso systems are:
- Food industry, Chemical, Petrochemical, Pharmaceutical
- Mineral processing, Manufacturing
- Excellent drying control
- Isolation from product
- Ability to control drying atmosphere
- Year of experience with all types of dryers
- Capable of installation anywhere in world
- True understanding of process conditions
- In house engineering for custom fit applications
Steam tube dryers have a series of tubes running down the length of the rotating shell and passing through the bed of feed material. Steam passes into the tubes, condenses and uniformly heats the feed material.
Rotary dryers are slightly inclined cylindrical shells supported by 2 riding rings running on a set of rollers. The kiln has a seal at both ends to prevent leakage in or out of air and material. Rotary dryers are suitable for drying a wide range of materials because of their ability to process materials having considerable variation in size and composition.
Because the steam is isolated from the material it is considered indirect heating. Using steam also allows for excellent heat/ drying control. Another advantage is the ability to control the inside atmosphere. This works well if an inert or sterile environment is required.
Important aspects to look at are:
What is the material?
What is the size and weight of the material?
What is the maximum temperature?
What is the quantity required to be dried?
What are the starting and ending moistures?