Lord Fin Tube-Brazing spiral fined tube
1. Brazed Spiral Finned Tubes Definition
Brazed spiral finned tubes represent a premium category of enhanced heat transfer surfaces where spiral fins are permanently bonded to a base tube using specialized brazing techniques. This metallurgical joining process creates a continuous, homogeneous metallic bond between the fin root and tube surface, resulting in superior thermal and mechanical properties compared to mechanical attachment methods.
2. Brazed Spiral Finned Tubes Structure and Materials
The structural integrity of brazed spiral finned tubes stems from the metallurgical bond formed during the brazing process.
Material Combinations
Copper Fins on Copper Tubes
Thermal Conductivity: 385-400 W/m·K
Max Service Temp: 250°C
Aluminum Fins on Carbon Steel Tubes
Thermal Conductivity: 200-220 W/m·K
Max Service Temp: 300°C
Stainless Steel Fins on Stainless Steel Tubes
Thermal Conductivity: 15-25 W/m·K
Max Service Temp: 600°C
Standard Dimensions
| Parameter | Range | Standard Value |
|---|---|---|
| Base Tube OD | 12.7 - 50.8 mm | 25.4 mm |
| Fin Height | 6 - 16 mm | 12.7 mm |
| Fin Thickness | 0.3 - 1.2 mm | 0.8 mm |
| Fins Per Meter | 157 - 433 | 275 |
3. Brazed Spiral Finned Tubes Manufacturing Process
The production of brazed spiral finned tubes involves precision engineering and controlled thermal processes.
Brazing Process Parameters
| Process Parameter | Copper Brazing | Aluminum Brazing | Stainless Steel Brazing |
|---|---|---|---|
| Brazing Temperature | 1100-1150°C | 600-620°C | 1050-1150°C |
| Atmosphere | Hydrogen or Vacuum | Controlled Air or Vacuum | Vacuum or Hydrogen |
| Filler Material | BCuP or BAg series | Al-Si alloys | BNi series |
4. Brazed Spiral Finned Tubes Comparison
Understanding how brazed spiral finned tubes compare to alternative technologies.
| Feature | Brazed Spiral Finned Tubes | Mechanically Attached | Integral Low-Finned Tubes |
|---|---|---|---|
| Thermal Resistance | Lowest (0 m²·K/W interfacial) | High (0.0002-0.0004 m²·K/W) | Low (0 m²·K/W) |
| Maximum Temperature | 600°C (material dependent) | 400°C | 350°C |
| Pressure Capability | Equal to base tube | Reduced due to grooves | Equal to base tube |
| Vibration Resistance | Excellent | Good | Excellent |
| Corrosion Resistance | Excellent (no crevices) | Poor (crevice corrosion) | Excellent |
5. Brazed Spiral Finned Tubes Application
Brazed spiral finned tubes are the preferred solution in demanding heat transfer applications.
► Power Generation
Economizers, air preheaters (APH), feedwater heaters in conventional and renewable power plants.
► Oil & Gas Processing
Heaters, coolers, and condensers in refineries and petrochemical plants.
► Chemical Processing
Reactor feed effluents, distillation columns, and process gas heating/cooling.
► HVAC&R Systems
High-efficiency heat exchangers for industrial refrigeration and air conditioning.