The core of titanium finned tube is the integrated formation of titanium based tube and titanium fins, which is used in chemical, seawater desalination, desulfurization, and pharmaceutical heat exchangers. Due to the high hardness, easy knife sticking, and poor thermal conductivity of titanium material, the processing technology is more special than ordinary carbon steel/stainless steel finned tubes. It is mainly divided into four mainstream methods: integral rolling, high-frequency welding of fins, wound brazing, and composite extrusion.

Mainstream processing techniques (advantages and disadvantages+applicable scenarios)

1. Overall cold rolling process

Applicable: TA1/TA2 pure titanium seamless tube, small diameter (φ 12.7-25.4mm), chemical condenser and cooler

Material preparation: Use seamless titanium light tubes, remove oil, acid wash passivation, and straighten

Pre annealing: Online low-temperature annealing of titanium tubes to reduce hardness, improve plasticity, and avoid rolling cracking

Three roll/multi roll rolling: a specialized titanium fin rolling mill that extrudes pipes with rolling rolls at room temperature and directly rolls spiral threaded fins onto the outer wall of the titanium pipe. The base pipe and fins are made of an integrated material without welding seams

Plastic shaping and sizing: straightening, cutting, wing height 0.5-3mm, teeth 19-42/inch

Advantages: high heat transfer efficiency, no gaps, consistent corrosion resistance, and no fouling; Disadvantage: Limited wing height, unable to enlarge large fins

2. High frequency welding process for titanium fins (preferred for large diameters and high fins)

Applicable: Titanium tubes with a diameter of 25-89mm, fins with a height of 5-16mm, for seawater desalination and large-scale chemical heat exchangers

Material preparation: titanium based tubes, titanium finned strips, with thoroughly deoxidized and degreased surfaces

Continuous feeding: The fins are spiral wrapped around the outer wall of the titanium tube

High frequency induction welding: 200-450kHz high-frequency heating, contact surface melting, extrusion roller pressure metallurgical bonding

Cooling+Inspection: Water cooling for shaping, penetration inspection for checking virtual welding and leakage welding

Advantages: tall wings, large heat exchange area, high efficiency; Disadvantage: The welding area is prone to oxidation and requires strict argon protection

3. Vacuum brazing/argon arc welding winding process (high anti-corrosion requirements, small batch)

Applicable: High purity media, chlor alkali industry, TA10/TA2 material

The titanium fin strip is tightly wrapped around the titanium based tube in a spiral manner

Vacuum furnace brazing (silver based brazing material for titanium) or argon gas shielded argon arc welding point by point welding

Acid pickling and passivation treatment

Advantages: firm connection, strong corrosion resistance; Disadvantages: Slow production, high cost, suitable for customized parts

4. Composite extruded fins (titanium tube+titanium fins integrated extrusion)

Applicable: serrated, high finned titanium finned tube, aviation, new energy heat exchange

Heat the titanium tube to 300-450 ℃

Special mold axial extrusion, directly extruding the integral fins

Advantages: The fins have extremely high strength and stable structure; Disadvantages: Large equipment investment, less mass production