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KL-Type Fin Tubes (Wrap-on Knurled Finned Tubes)
The KL-Type fin tube is a wrapped fin tube that enhances heat transfer performance through a specialized knurling process. Its core feature involves machining knurled patterns onto the base tube surface before winding the fin strip, forming a tightly wrapped structure. Key technical characteristics and applications are as follows:
I. Wrap-on Knurled Finned Tubes Structural & Process Features
- Pre-Knurled Base Tube
Before aluminum strip winding, specialized equipment rolls axial or helical grooves/textures onto the base tube (carbon steel, stainless steel, etc.). This process increases the contact area between the fin and base tube by approximately 50%. During winding, mechanical force embeds the fin root into the grooves. - Secondary Rolling Reinforcement
After winding, the fin root undergoes secondary rolling to further eliminate gaps and enhance tube-fin bond strength. This “wrapped” structure withstands repeated thermal cycling without loosening.
II. Wrap-on Knurled Finned Tubes Performance Advantages
- High-Efficiency Heat Transfer
Contact thermal resistance is reduced by over 30% compared to standard L-Type fin tubes, significantly improving the heat transfer coefficient. Experimental data shows KL-Type provides 15%-20% higher heat dissipation than L-Type under identical conditions. - High-Strength Bonding
The knurled grooves create a mechanical interlock structure, achieving pull-off resistance up to 1.5 times that of conventional products, making it suitable for vibrating environments. - Temperature & Pressure Resistance
Maximum continuous operating temperature reaches 250°C (280°C peak), with pressure resistance up to 3.2MPa, meeting most industrial requirements.
III. KL-Type Fin Tubes Typical Application Fields
| Application Scenario | Equipment Type | Key Advantages |
|---|---|---|
| Industrial Workshop Heating | Steel spiral-wound fin tube radiators | Resists thermal cycling, service life >10 years |
| Petrochemical/Power Systems | Air coolers, waste heat recovery units | High heat transfer efficiency, reduces energy consumption |
| Agricultural Greenhouses | High-frequency welded fin tubes for greenhouses | Uniform heat distribution, rapid heating |
| Drying Equipment | Air heaters for spray drying systems | Stable high-temperature performance |
IV. Technical Limitations
Note: Aluminum fins may corrode in strong acid/alkaline environments. Production costs are ~20% higher than standard wrapped fin tubes37. Current processes are primarily suitable for tube diameters of Φ25-Φ89mm; achieving uniform knurling on larger diameters remains a technical challenge.
