三方機械工業股份有限公司

1. Background & Issues

In pneumatic conveying of powders and granules, elbows are prone to:

• Wear damage: Impact of conveyed material causes rapid wall erosion.
• Product degradation: Particle breakage or coating delamination.
• Energy loss: Turbulence and velocity drop lead to pressure loss.
• Blockage: Powder accumulation causes clogging.

Limitations of conventional solutions:

• Right-angle elbows: Concentrated impact accelerates wear.
• Long-radius elbows: Milder impact angle but larger contact area increases resistance.
• Tee-type: Powder buildup causes blockage.
• Deflector-insert type: Becomes unusable after insert wear; complex fabrication and installation.

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2. Structural Features

The Wear-Resistant Spiral Elbow integrates an involute-shaped spiral chamber mid-elbow to split, decelerate, and recombine the flow.

Main Structure:

1. Spiral Chamber
   1. Protrudes outward in an involute profile.
   1. Cross-section expands from inlet to outlet (helical form).
   1. Flow distribution:
      1. ~19.5% flows directly through the main passage (high speed, negative pressure).
      1. ~80.5% enters the spiral chamber (decelerated, positive pressure).
   1. Induces vortex flow to divert from high-wear zones.
2. Intersecting Partition
   1. Positioned where the spiral chamber inlet meets the elbow curve.
   1. Controls split ratio and flow direction.
3. Standard Flanges
   1. Inlet/outlet comply with standard steel pipe specifications.
   1. Flanges cast integrally with the elbow for easy installation.
4. Support / Lifting Lugs
   1. Located outside the spiral chamber for mounting or lifting.
   1. In emergency situations, it can function as an auxiliary port for secondary pressurization and abrasion protection.

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3. Operating Principle

• Flow Equation: Q = A × V (Flow rate = Area × Velocity)
  Expanding cross-section reduces velocity, increasing pressure.
• Bernoulli’s Principle:
  • Spiral chamber: Deceleration forms a positive-pressure zone.
  • Main passage: Direct flow forms a negative-pressure zone.
  • Pressure differential enables smooth recombination, minimizing turbulence and direct impact.

Result:

• Avoids concentrated wear zones (impact points).
• Disperses impact, preventing particle breakage and powdering.
• Reduces energy loss and maintains steady velocity.

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4. Advantages

1. Enhanced wear resistance: Longer service life.
2. Energy saving: Lower pressure loss, reduced need for boosting.
3. Compact: Smaller footprint than long-radius elbows.
4. Anti-buildup: Spiral chamber resists powder accumulation.
5. Easy installation: Standard flanges + support points.
6. Material versatility: Cast iron, cast steel, stainless steel, wear-resistant alloys, ceramic linings, etc.
7. Wide applicability: From food to chemical, mining, and construction materials.

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5. Summary

This wear-resistant spiral elbow delivers wear protection, energy efficiency, and space savings in one design, addressing the root causes of conventional elbow failure.