Having knowledge of all types of Industrial Dryers is important for proper selection of industrial dryer. Because of this I am going to cover basic to mid level information about industrial Dryers.
Hello friends, thank you for coming here to my article. My name is B. Kadam, and today I am going to share my knowledge regarding industrial dryers. Here, you will get information about industrial dryers from my experience, meaning from an industrial point of view, not an academic point of view. I have shared practical information here that will help you select the right dryer as per your needs, as well as help you crack the interview as a process design engineer.
This article covers what an industrial dryer is and its importance, types of industrial dryers with their advantages and disadvantages, applications of industrial dryers, selection of industrial dryers, frequently asked questions about them, pro tips, and conclusion.
Drying is unit operation or process? read this article to get more clarity o it. “Unit Operation and Unit process“.
Table of Contents
What is dryer?
A dryer is mechanical equipment or a machine used to remove moisture or liquid from solids. In simple terms, it is a machine that dries material using a heating system.
Types of Industrial Dryer
following are the main types of dryer used in industry.
Tray Dryer | TD
TA tray dryer is a type of industrial dryer that contains trays inside the chamber where the material is placed for drying. With the help of a heating system, the material is heated to achieve drying.
Key Components of Tray Dryer
- Trays
- Drying Chamber
- Control Panel
- Heating System
Advantages
- Simple to use.
- Less maintenance as compared to other dryer.
- Easy to operate.
- Good for Small capacity project.
Disadvantages
- Not suitable for bond and equilibrium moisture
- Not good for material where we need High temperature to get dry
- Manual handling
- Need more labor for loading and unloading.
- Not good for sensitive material
Vacuum Tray Dryer | VTD
Vacuum Tray Dryer is a commonly used dryer in the chemical and pharmaceutical sectors. This dryer contains trays inside it where the material is dried. In this dryer, we use vacuum to reduce the boiling point of the liquid inside the material so we can easily remove all the liquid from it. Below is an example of a Vacuum Tray Dryer.
Key Components of VTD
key components are,
- Drying Chamber
- Trays
- Heating System
- Vacuum Pump
- Vent Condenser
- Receiver
- vacuum Catch-pot
Advantages
- Good for health sensitive material
- Use of vacuum will result in energy saving.
- Good for bond moisture.
Disadvantages
- Not Suitable for bond moisture and equilibrium moisture.
- We can use in batch operation only.
- Need more labour for loading and unloading operation.
- Need more space for Tray storage
Fluidised Bed Dryer | FBD
Fluidised Bed Dryer is a type of industrial dryer which uses hot air to dry the material. In this dryer, we pass the hot air through the material, which fluidises the material and removes the free as well as bound moisture. Typically, it is used to remove the bound moisture. Normally, we remove the free moisture in a vacuum tray dryer and after that, we send it to the Fluidised Bed Dryer to remove bound moisture. If the material is air-sensitive, we can use N2 to dry it. this main types of dryer.
Key Components of Fluidised Bed Dryer
- Drying chamber
- Heater or heat exchanger to heat the air
- Air blower or compressor
- Filters to filter the air
- Drying bag
- Exhaust System
Advantages
- Good to remove the bond moisture
- Continuous mixing of particles with air remove moisture uniformly.
- Suitable for small scale .
Disadvantages
- We can’t use for free moisture
- small or sticky particles may be clog
- High Capex
Rotory Cone Vacuum Dryer | RCVD
Rotary Cone Vacuum Dryer (RCVD) is a type of dryer mostly used in the pharmaceutical and specialty chemical industries. It contains a rotating cylinder where we load the material for drying. Below is an actual image of a Rotary Cone Vacuum Dryer.
It is a types of dryer used in chemical industry.
Components of Rotary cone vacuum dryer
- Rotary cone vessel
- Vacuum pump
- Vacuum catch pot
- Heating System
- Heat exchanger
- Reciver
- Cloth bag
- Control Pannel
Advantages
- Good for heat sensative material
- we can dry at low temperatures with mixing
Disadvantages
- High Capex
- High maintenance because of rotating components
Agitated Nutch Filter Dryer | ANFD
Agitated Nutsche Filter Dryer is a machine which we use in the pharmaceutical and chemical industries for drying as well as filtration applications. It a types of dryer in pharmaceutical industry.
For some materials, we don’t want to expose them more to the atmosphere, so we can use this dryer where we can do filtration first and then dry the material. We can also wash the material if required to achieve good purity.
Key Components of ANFD
- Filter Vessel
- Filter Media i.e. cloth
- vacuum pump
- Vacuum Catch-pot
- Agitator
- Heating System
- Heat exchanger
Advantages
- We can use it for filtration as well drying
- We can use for product washing too.
- We can use steam or oil for heating
Disadvantages
- Initial investment (capex) can be high
- Difficult to get big size
- Maintenance is expensive
Application of Dryer
- Drying of Active Pharmaceutical Ingredients (APIs)
- Dehydration of Food Products
- Drying of Chemical Compounds
- For Drying catalysts
- Fabric Drying
- Paper and Cardboard Drying
Selection of Dryer
Selection of dryers is depends on many factor like type of moisture. There are three types of moisture: free moisture, bound moisture, equilibrium moisture. So depends upon the type of moisture we can select the dryer. Another factor is heat sensitivity, temperature requirement, material is explosive or not. Costing, operation wise batch or continuous. Also, it depends on other factors too. We will come with another article where we cover one example to get understanding of dryer selection.
Pro Tips on Types of Dryer
If you are working in the pharmaceutical or chemical industry, you must have basic knowledge regarding dryers. Basic knowledge should cover types of dryers with their advantages and disadvantages, when to use which dryer, and also the parts of dryers. If you are going to attend an interview, please prepare for the selection and parts of dryers, as this is very important.
Frequently Asked Questions and Answers
When we can use VTD?
We can use this when the material is heat-sensitive, also if we want low-temperature drying, and when the material contains bound or hygroscopic moisture.
What is advantage of vacuum in dryer?
Lower boiling points, prevents oxidation, faster drying at lower temperatures, and reduces thermal degradation.
What is advantage of rotation in dryer?
Improved mixing, enhanced heat transfer, and prevention of material sticking.
which on is good VTD or TD?
VTD is good for heat-sensitive materials. TD is simpler as well as cheaper for less sensitive materials
What are Two advantages of rotary cone vacuum dryer?
Number 1 Efficient for pasty/viscous materials and number two vacuum environment ensures low-temperature drying.
What are Two disadvantage of tray Dryer?
Number one is Slower drying , number two is non-uniform drying.
Which are five factors for selection of industrial dryers?
Material properties, drying capacity, energy efficiency, drying time, and cost considerations.
Which on is costly industrial dryer?
ANFD and RCVD.
Conclusion
Types of dryers used in the industry are TD, FBD, RCVD, VTD, and ANFD. The selection of a dryer depends on the properties of the material, sizing, operation (batch or continuous), CAPEX and OPEX, maintenance cost, type of moisture, and heat sensitivity of the material.
Read Also,
Types of Reflux In Distillation Column
Line sizing calculation with example
Types of dryer in pharmaceutical industry
External References
Discover more from Technical Guide
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