dtfinnedtube.com
Datang is the professional of the technical specifications for L-fin tubes and KL-fin tubes:
The KL type solves the contact thermal resistance and high temperature loosening problems of the L type through the base tube knurling and double fin design, achieving higher heat transfer efficiency and structural stability
Core Features of L-Fin Tubes
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Structure & Manufacturing
- Mechanical Wrapping: Metal strips (steel/aluminum) are cold-spiraled onto base tubes via mechanical force, forming L-shaped crimped roots at the fin base.
- Knurled Design: Surface knurling enhances airflow turbulence, improving thermal efficiency (heat dissipation area 3–5× larger than bare tubes).
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Performance Parameters
- Material Compatibility: Carbon/stainless steel base tubes (Φ50–89 mm); aluminum strips (thickness: 0.2–0.5 mm) typically used for fins.
- Temperature Tolerance: Aluminum fins ≤70°C; steel fins ≤350°C.
- Precision Control: Fin height tolerance ±0.5 mm; fin spacing adjustable (2.3–8 mm; min. spacing ≥2.3 mm).
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Limitations & Improvements
- Higher contact thermal resistance; prone to loosening at elevated temperatures (aluminum fin bond strength degrades >70°C);
- Corrosion protection relies on surface treatments (painting or hot-dip galvanizing; electroplating obsolete).
KL-Fin Tubes Technical Features
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Structural Innovation
- Double L-Fin Design: Dual-layer aluminum strips form an LL-shaped structure, enhancing rigidity and bond stability.
- Tight Fin Spacing: Minimum spacing of 2.3 mm increases heat transfer area per unit length by 30% vs. standard L-fins.
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Performance Advantages
- Anti-Collapse: Dual-fin configuration reinforces mechanical strength, resisting deformation during transport/high-velocity airflow.
- Media Compatibility: Preferred for stable fluids (hot water/coolant); limited suitability for steam/thermal oil applications.
Industrial Applications Comparison
| Type | Application Scenarios | Typical Use Equipment | Key Advantages |
|---|---|---|---|
| L-Fin Tubes | Low-temp drying, CHAUFFAGE | Textile dryers, greenhouse heating36 | Low cost, easy replacement |
| KL-Fin Tubes | Precision temperature control | Constant-temperature workshops, spray dryers5 | High heat density, low flow resistance |
Selection Guidelines
- Prioritize KL-Fin Tubes when:
- Requiring fin spacing ≤3 mm for high-efficiency heat transfer;
- Operating in clean environments with temperature fluctuations <50°C (avoids fouling).
- Avoid L-Fin Tubes when:
- Handling steam (>150°C loosens fins);
- Exposed to highly corrosive flue gas (requires additional coatings).
Industry Trend: High-frequency welding progressively replaces traditional wrapped L-fin tubes to eliminate contact thermal resistance.
