types

Tangential flow impulse

July 30, 2025
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Tangential flow fans are one of  the most specialized  types of industrial motors, producing unique flow patterns. And by   generating tangential flow along the vessel  wall, these fans are an ideal solution for shear sensitive applications. This article  will analyze the principles of its operation, advantages, design and industrial applications.

What is a motive with apparent flow?

A tangential flow impeller is   an industrial motor with the   following characteristics:

  •  The fluid flow is directed  parallel to the tank wall.

  •  Generates  low shear stress

  •  Suitable   for shear-sensitive fluids (cells, polymers, proteins)

  •  Produces  a concentrated vortex flow pattern

The main types of tangential fans

  1. Anchor impeller

    • Near the wall of the reservoir

    • Suitable for liquids with high viscosity.

  2. Spiral belt motor

    • Spiral design

    • Excellent performance in non-Newtonian liquids

  3. Gate fan

    • Simple structure

    • Low power consumption

Mechanism of operation and design

Principle of operation

  • The rotation of the impeller   moves the liquid along the perimeter of the tank.

  • The primary   flow is generated in the tangential direction and the secondary flow is   generated in   the vertical direction.

  •  Apply  controlled centrifugal force.

Main design parameters

range Optimal range Impact on performance
Diameter ratio (D/T) 0.7-0.9 Increased heat transfer
speed 10-100rpm Shear stress control
Snail angle 30-45 degrees Improved vertical flow
Distance from wall 5-10% of tank diameter Rainfall prevention

Unique Features

  1. Minimum shear   strength compared to other types

  2. Homogeneous and homogeneous   without  destroying  the molecular structure.

  3. Efficient   heat transfer during heating/cooling

  4. Flow   stability at different viscosities

  5. Prevents   deposition on the walls of the tank.

Professional Applications

1. Biotechnology and pharmaceutical industries

  • Cell culture and fermentation

  • Production of vaccines and antibiotics

  • A combination of biologically sensitive substances

2. Polymer and resin industry

  • Production of composite materials

  • Hybrid thermoplastic  materials  

  • Rubber and elastomer treatment

3. Food industry

  • Production of chocolate and cocoa

  • Thick pasta processing

  • Preparation of emulsified sauce

4. Chemical industry

  • Production of paints and coatings

  • Polymerase process

  • Mixed adhesive

How to choose and calculate

Criterias of choice

  1. Sensitivity of materials to sternal stress

  2. Rheological properties of liquids

  3. Tank size  and geometry

  4. Heat transfer requirements

Main formula

  • Capacity(Po)  : P/(ρN³D⁵)

  • Reynolds Number (Re)  : (ρND²)/μ

  • Pumping capacity (Q)  :    kND³ (coefficient k between 0.5-1.2)

Challenges and practical solutions

Frequently asked questions

  1. Not mixing enough in the center of   the tank

  2. Very   high viscosity and high energy consumption.

  3. Corrosion   in aggressive chemical environments

Optimization Solutions

  • Use   of the composite   fan (tangential-vertical)

  • Install    vertical barriers to   optimize   flow

  • Choose   corrosion-resistant materials,   such as Hastelloy or Teflon paint.

Performance comparison table

feature Tangential flow Radial flow Axial flow
Shear stress Odd Top half
Applicable viscosity Top Low to medium A little
Heat transfer Excellent half Weak
Power consumption Medium to High Top A little

Maintenance & Operation

  1. Check the   distance between the payer and the wall every month

  2. Periodic   fan balancing control

  3. Lubricate   bearings periodically

  4. Removal   of sediment from the surface of the impeller

Conclusion

Tangential   flow fans occupy a special place in advanced industrial applications thanks to  their unique ability to handle sensitive materials. The careful selection of these fans, based on  process conditions and fluid properties,  can improve  product quality and reduce production costs.

Frequently asked questions

1. What is the main difference between tangential impulse and radial impulse?

Tangential fans generate less cut and are more suitable for sensitive materials, while radial fans have greater mixing strength.

2. Can these impellers be used for liquids with low viscosity?

Yes, but they may require  adjustments in rotation  speed and special designs.

3. What is the life expectancy of these butterflies?

From 5 to 10 years depending on the type of butterfly and working conditions.

4. What are the most important design criteria for these fans?

  • ISO 2858  Dimensions and Tolerances 

  • ASME BPE   for Pharmaceutical and Food Industries