Do you know about the drying process in industries? If yes, you must be aware of the constant competition between two machines, Single Pass against Triple Pass Dryers. A rotary dryer is a machine used in industries that helps dry ores and minerals into small pieces for fertilizers.
However, it is difficult to choose which dryer is the best. There are so many rotary dryer manufacturers offering different types that it is hard to buy one. In this article, we will go into the details about what are the different types of industrial rotary dryers and which one is better.
ROTARY DRUM DRYERS
Rotary dryers are a highly efficient industrial drying option for drying raw materials in large quantities. They are used for their advanced technology. This technology helps in the processing of different raw materials into small pellets. These are then used for fertilizers and feedstock.
This dryer works by moving material into the rotating drum. Dry air is constantly passing through this chamber. You can also heat it indirectly to avoid any contact between the raw material and the processing medium.
The drum is placed in a slightly horizontal position. This allows gravity to help biomass materials move in the machine. As the drum rolls, it picks up material and then passes it through steam of air. This helps in increasing heat transfer efficiency.
If you are dealing with agglomerates, the tumbling action of the dryer also rounds and polishes the granules.
More Info for Rotary Drum Dryers Please Read The Article > Advancements in Biomass Drying Technology: Rotary Drum Dryers
Working of ROTARY DRUM DRYERS
Let us discuss in detail the working of these dryers in easy steps as below:
- Wood chips, sawdust, or other material is fed to the machine. The conveyor takes material inside the machine.
- From there, it goes to the cylinder.
- Hot air will move through this material. It helps in drying of the raw material. You can then collect the material at the outlet.
- During the rotary drying process, there is a cylindric rotation inside the drum. Gravity helps material from high-end to low-end.
- You can also use copy boards in the dryer to raise the material. It is important to increase the surface area of the material and hot air. This, in turn, helps to increase the drying rate and moves the material forward.
- Once dried, these fine particles are collected by the dust collector. Exhaust gas is discharged by the dust collector.
Single Pass and Triple Pass Types of Dryer
Now that we understand how a dryer works, let’s find out its different types. There are two main types of rotary drum Dryer.
- Direct Rotary Dryer: The material flows directly through the rotating drum. Here, it has direct contact with the drying air.
- Indirect Rotary Dryer: In this dryer, the heat is applied to the exterior of the drum. Here, you have to dry the material indirectly through conduction.
- Concurrent (Co-Current) Rotary Dryer: In this dryer, the drying air and material flow in the same direction. This helps to increase the efficiency of heat transfer.
- Counter-Current Rotary Dryer: The drying air and material flow in opposite directions. This helps in a better exchange of heat and increased efficiency.
Some of the other types are:
- Single Pass Rotary Dryer
- Triple Pass Rotary Dryer
Both of these dryers work in almost the same way. However, there are some differences. Let us learn about the similarities and differences between both of these.
Similarities Between the Triple Pass and Single Pass Rotary Dryer
To understand what is the same between these dryers, let us take an example of drying sand.
- Both of them can dry out sand that is wet. A single-pass rotary dryer or a triple-pass rotary drum dryer both dry the sand by contacting it with hot air and letting the wetness escape.
- Both have running systems that are simple to use. Easy-to-use control methods will help you change technical details like the dryer’s temperature, speed, and feed volume on both triple-pass and single-pass rotary drum dryers.
- The heat source for both dryers can be changed, so they can use coal, gas, or biomass pellets.
- Both can dry different things, like sludge, fly ash, sand, and more.
Difference Between Triple Pass and Single Pass Rotary Dryer
It is important to know the key differences between both these dryers. These differences help you choose the dryer that best suits your needs. Let us take a look at how these two dryer types differ in working and their design.
1- SINGLE PASS ROTARY DRYERS
Single-pass rotary dryers have one heavy-duty drum that feeds material and combustion products while the drum rotates. The drum is set on a small slope to help the material move through.
Attached to the inside of the drum are flights that pick up the material and throw it through the gas stream as the drum turns. This makes the best heat transfer between the material and the combustion products.
Single-pass rotary dryers are used for a lot of different materials in a lot of different businesses. They can be adjusted depending on the needs of the material.
2- TRIPLE PASS ROTARY DRYERS
Triple-pass rotating dryers have three drums inside each other, each with a different diameter and less weight. Instead of being set on a slope, the drum is moved through the unit by air conveying.
Things are put into the interior drum and pushed out the end, where they land in the middle drum. In the same way, the material moves through this drum, out the end, and into the last drum shell, where it moves through and is released at the end.
Most of the time, triple-pass dryers are used in high-moisture situations where durability is not as important. Because of this, they are often used to dry different kinds of waste.
Conclusion
A comparison of Single Pass and Triple Pass Rotary Drum Dryers shows that both have their own strengths when it comes to drying speed. The small differences in their features help you make choices based on the properties of the material and the needs of the production process. Before you start drying, you might want to make sure that the choice you make fits the needs of your business.
Feel free to get in touch with our experts if you need personalized help setting up the best rotating drum dryer. Making a smart choice is the first step toward drying as efficiently as possible. Contact us right away to make sure that your cleaning process not only meets but also exceeds your needs.