Types of Agitators | Propellers | Turbines | Radial and Axial flow impeller | PBT | Anchor | Helix .

Summary

This video dives into the world of agitators, focusing on various types used in mixing and agitation processes. It explains the differences between axial flow and radial flow impellers, which determine the direction of the flow they create. The video also covers different agitator types like propellers, turbines (including simple plate, disc, concave blade, and pitch blade turbines), and high-efficiency impellers. Additionally, it discusses specialized impellers for handling highly viscous liquids. Viewers are guided through the selection of agitators based on liquid properties, emphasizing efficiency and the specific needs of industrial mixing applications.

Takeaways

• 😀 Agitators, also called mixers or impellers, are devices used to mix liquids in industrial processes.
• 😀 Agitators can be classified based on flow direction into **axial flow** and **radial flow** types.
• 😀 Axial flow impellers move liquid in a parallel direction to the shaft, creating a vertical current.
• 😀 Radial flow impellers move liquid outward in a tangential direction, similar to a spinning wheel's motion.
• 😀 **Propeller agitators** are used for low-viscosity liquids, spinning at high RPM to create swirling flow.
• 😀 **Turbine agitators** come in several types: simple straight blade, disc turbine, concave blade (CD6), and pitch blade turbine, each with specific applications.
• 😀 Disc turbines create high shear force, ideal for mixing gases into liquids by forming small bubbles.
• 😀 Pitch blade turbines combine axial and radial flow, useful for general circulation in various mixing applications.
• 😀 **High-efficiency impellers** like the HE-3 and A310 fluid foil impellers improve mixing efficiency and reduce energy use.
• 😀 Agitators for high-viscosity liquids include **helical ribbon impellers** for very thick liquids and **anchor impellers** for heat transfer and bottom agitation.
• 😀 Each type of agitator is selected based on the liquid's properties and the desired mixing effect, ensuring optimal process performance.

Q & A

What is the main difference between axial flow and radial flow impellers?

Axial flow impellers move liquid in a direction parallel to the impeller shaft, like stirring a liquid up and down. Radial flow impellers, on the other hand, move liquid outward, like a spinning wheel.

Can you explain how propeller agitators work?

Propeller agitators mix liquids by spinning rapidly, creating a swirling motion that pushes the liquid downward. This continuous motion helps break up the liquid into smaller pieces, especially useful in large containers.

What is the RPM range for propeller agitators in smaller vs larger containers?

For smaller propeller agitators, the RPM range is typically between 1150-1750 RPM, while for larger units, the RPM range is around 400-800.

How do turbine agitators differ from propeller agitators?

Turbine agitators have different blade designs and create varying flow patterns. While propellers create swirling motion, turbines can generate both radial and axial flows depending on the type, such as simple straight plate turbines or pitch blade turbines.

What is the main application of a disc turbine agitator?

Disc turbine agitators are particularly useful for mixing gases into liquids. They work by forcing gases towards the tips of the blades at moderate speeds, using high shear force to break the gas into tiny bubbles for efficient mixing.

What is the difference between a simple straight plate turbine and a pitch blade turbine?

A simple straight plate turbine primarily pushes liquid radially with little vertical movement, while a pitch blade turbine combines both axial and radial flow to improve circulation and overall mixing.

What is a high-efficiency impeller, and why is it important?

High-efficiency impellers are designed to improve mixing efficiency and reduce power consumption for a given flow rate. They are commonly used in applications requiring better mixing without increasing energy usage.

How do HE-3 and A310 fluid foil impellers improve mixing efficiency?

The HE-3 impeller uses three slanted blades to ensure more uniform axial flow, while the A310 fluid foil impeller features airfoil-shaped blades that improve mixing in low-to-moderate viscosity liquids, both reducing power requirements for mixing.

What type of impeller is used for high-viscosity liquids, and how do they work?

For high-viscosity liquids, impellers like the helical ribbon impeller and anchor impeller are used. The helical ribbon impeller is suitable for very thick liquids (up to 25,000 Pascal-second), while the anchor impeller provides agitation near the tank bottom and promotes heat transfer.

What are the advantages of using multiple propellers on the same shaft in deep tanks?

In deep tanks, multiple propellers on the same shaft are used to ensure that the liquid is mixed thoroughly. These propellers push the liquid in the same direction, ensuring efficient circulation throughout the tank.