1. Overview of Nanjing Industrial Heat Exchanger Cleaning Demands
As a key industrial city in the Yangtze River Delta, Nanjing hosts multiple large industrial clusters including the Jiangbei New Materials Science and Technology Park, Nanjing Chemical Industrial Park, and Jiangning Economic and Technological Development Zone — with dense concentrations of chemical, power, steel, and pharmaceutical industries maintaining an enormous installed base of heat exchangers. The Yangtze River water in the Nanjing section has relatively high hardness, with pronounced scaling tendencies in circulating cooling water systems. Heat exchangers typically experience 20%–40% heat transfer efficiency decline after 6–12 months of operation, making regular chemical cleaning an essential maintenance measure for ensuring efficient production unit operation.
Danyang Blue Star Cleaning is located in Danyang, Zhenjiang — only 80 km from downtown Nanjing, approximately a 1-hour drive — enabling rapid response to heat exchanger cleaning needs across all of Nanjing. The company is a member of the China Industrial Cleaning Association with 20 years of industry experience, having cumulatively served over 100 enterprises in Nanjing and surrounding areas.
2. Common Heat Exchanger Issues in Nanjing
Affected by the Yangtze River water quality, heat exchanger scaling in Nanjing is predominantly CaCO₃ water scale, with some chemical installations experiencing accompanying silicate scale and iron oxide deposits. Common issues include: shell-and-tube heat exchanger tube bundle internal and external wall scaling causing heat transfer efficiency decline, plate heat exchanger inter-plate flow channel blockage causing increased pressure differential, and spiral-plate heat exchanger weld zone stress corrosion. Differentiated chemical cleaning solutions must be developed based on scale types and equipment types.
With Nanjing's hot and humid summers and cold winters, heat exchanger cleaning windows typically concentrate during the March–May and October–November annual maintenance seasons. Blue Star Cleaning supports year-round emergency response, including holidays.
3. Heat Exchanger Chemical Cleaning Technical Solutions
The following cleaning solutions are adopted for mainstream heat exchanger types in Nanjing:
Shell-and-Tube Heat Exchangers: 8%–10% HCl or 5%–8% Sulfamic Acid circulation cleaning, combined with Urotropine (0.3%–0.5%) inhibitor and Surfactant penetrant. For stainless steel tube bundles, Sulfamic Acid systems are preferred to avoid Cl⁻ stress corrosion cracking risks. NaOH neutralization and NaNO₂ passivation treatment are performed after cleaning.
Plate Heat Exchangers: After disassembly, 3%–5% Citric Acid soak cleaning is employed, combined with Sodium Molybdate corrosion inhibition protection. Citric Acid offers high safety for stainless steel plate surfaces and can complex iron oxides; simple water flushing after cleaning is sufficient without additional neutralization steps.
Spiral-Plate Heat Exchangers: Sulfamic Acid + Citric Acid composite formulation circulation cleaning is used, with MBT (0.1%–0.3%) as the inhibitor, focusing on protecting spiral body weld zones. Cleaning flow velocity is controlled at 0.5–1.0 m/s to ensure uniform scale stripping within flow channels.
4. Nanjing Service Coverage and Response Times
Coverage includes all administrative districts of Nanjing — Gulou, Xuanwu, Qinhuai, Jianye, Qixia, Yuhuatai, Jiangning, Pukou, Luhe, Lishui, and Gaochun Districts. Key industrial parks such as Jiangbei New Materials Science and Technology Park and Nanjing Chemical Industrial Park operate under a 2-hour rapid response mechanism: upon receiving a service call, engineers arrive on-site the same day for inspection and issue a cleaning plan. Routine heat exchanger cleaning projects are completed within 2–5 working days; large installations within 10 working days.
5. Nanjing Service Case Study
Case: Shell-and-Tube Heat Exchanger Cleaning for a Nanjing Chemical Enterprise
Equipment parameters: Carbon steel shell-and-tube heat exchanger, heat exchange area 180 m², tube-side medium circulating cooling water, shell-side medium organic solvent vapor. After 14 months of operation, outlet temperature deviated 18°C from the design value, with tube bundle inner wall scale thickness of 2–4 mm.
Cleaning solution: 8% HCl + 0.4% Urotropine + 0.1% Surfactant cleaning agent formulation, circulation cleaning temperature 55–65°C, cleaning duration 5 hours. Pre-cleaning coupon test corrosion rate: 1.5 g/(m²·h), inhibition efficiency 96.2%, exceeding national standards. Post-cleaning heat exchange efficiency recovered to 94% of design value, steam consumption reduced by 17%, yielding annual energy cost savings of approximately ¥210,000.
6. Why Choose Blue Star Cleaning
20 years of deep industry experience with cumulative completion of over 500 heat exchanger cleaning projects; Member of the China Industrial Cleaning Association with cleaning processes conforming to GB/T 25146-2010 standards; 2-hour response across Nanjing with on-site arrival within 24 hours; Transparent cleaning agent formulations with complete cleaning reports and coupon corrosion data provided; Waste liquids neutralized per environmental standards for compliant discharge.