Titanium Heat Exchangers Of Seawater Desalination Equipment
We have cases of titanium tube for heat exchanger in seawater desalination to prove that titanium is the best material for heat exchangers of seawater desalination equipment.The results due to the best performance in corrosion resistance of titanium in seawater. We are 20 years manufacturer in titanium tube/fittings and vessels in China. We hope you have interested in our products shown below.
Product Introduction
1. Case Studies
St. Croix Desalination Plant (Virgin Islands, mid-1960s)
Capacity: 1.5 million gallons/day.
All heat exchangers used titanium tubes, solving the corrosion problems of copper alloy exchangers.
1970s (St. Croix, Al Joubail, etc.)
Used 5.7 million meters of thin-wall welded titanium pipes.
Top seawater heater temperature reached 140 °C.
Global Usage (1995)
Over 14 million meters (4,250 tons) of titanium pipes applied in desalination plants worldwide.
Equipment included: evaporators, condensers, air-jet pump condensers, and other exchangers.
2. Corrosion Resistance of Titanium
Stable TiO₂ oxide film:
Excellent resistance in aggressive media.
Self-healing in moisture or cold water, even after damage or welding.
Advantages over stainless steels:
No susceptibility to dimple corrosion.
Immune to microbial corrosion.
Resistance to cavitation corrosion:
Flowing seawater impact does not damage titanium at velocities ≤ 30 m/s.
Erosion test results:
Seawater condition | Erosion rate |
Velocity 7 m/s | No erosion |
Velocity 36 m/s | 0.008 mm/a |
2 m/s, 40 g/L sand, 60 mesh | 0.003 mm/a |
2 m/s, 40 g/L sand, 10 mesh | 0.013 mm/a |
4.1 m/s, 4% particles | 0.008 mm/a |
Stress corrosion cracking:
Industrial pure titanium (Gr1, Gr2) highly resistant in natural water, seawater, and chloride environments.
Fouling resistance:
At flow rates 3–5 m/s → minimal biological fouling.
Titanium heat exchangers have fouling coefficient 0.95–0.99 (higher than copper alloy 0.85).
Retains protective oxide film even under fouling, reducing cleaning needs.
3. Common Titanium Materials for Heat Exchangers
ASTM Gr2: Widely used industrial pure titanium.
Gr7, Gr12: For high-temperature seawater heaters (up to 130 °C).
Gr16 (Ti-0.5% Pd): Superior corrosion resistance, but higher cost.
Design considerations:
Long-tube (≥15 m), parallel or longitudinal flow → Gr7, Gr12, or Gr16 preferred.
Horizontal-flow or partial titanium usage → higher alloy grades only in critical sections.
No additional protection needed:
Titanium tubes do not require coatings, sacrificial anodes, or cathodic protection.
4. Advantages of Titanium Heat Exchangers
Operational benefits:
Reduced downtime and maintenance due to superior corrosion resistance.
Resistant to vibration; thin-walled design enhances thermal performance.
Optimized tube-sheet and support plate structures allow thinner tubes → improved heat transfer efficiency.
Economic impact:
Lower lifecycle cost vs. copper alloys (due to longer service life).
Limited galvanic corrosion when combined with other materials.
Productivity increase of 3–4% reported in power plants after adopting titanium condensers.
Summary:
Titanium tubes revolutionized seawater desalination heat exchangers by eliminating corrosion issues common to copper alloys and stainless steels. With proven performance in high-temperature, high-flow, and sand-laden seawater, titanium provides unmatched durability, fouling resistance, and long-term cost-effectiveness.
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