1. Yangzhou's Industrial Profile and Cleaning Demands
Yangzhou governs three urban districts (Guangling, Hanjiang, Jiangdu) and three counties (Yizheng, Gaoyou, Baoying), forming a diverse industrial base. The Yizheng Chemical Industrial Park hosts multiple chemical enterprises. Guangling and Hanjiang districts concentrate machinery manufacturing and automotive parts suppliers — several German and Japanese Tier-1 suppliers operate precision machining facilities here. Gaoyou, nationally recognized as China's "Cable Capital," is home to hundreds of cable manufacturers whose wire-drawing cooling systems require meticulous maintenance. Yizheng's riverside zone accommodates several mid-to-large shipyards. The automotive parts sector has grown rapidly in recent years, with precision equipment demanding strict cleanliness standards for cooling and hydraulic systems.
The Yangtze River, flowing through southern Yangzhou, serves as the primary source of industrial cooling water. With total hardness of 120–160 mg/L (as CaCO₃) and suspended sediment, prolonged use inevitably leads to scale deposition in heat exchange equipment. Combined with Yangzhou's hot, humid summers, cooling towers and chillers are prone to microbial growth. Fouling patterns vary by industry: chemical plants primarily face CaCO₃ scale, Fe₂O₃ corrosion products, and organic polymer residues; machinery manufacturers deal with carbonized lubricant deposits; cable producers encounter mixed scale and bio-slime in wire-drawing cooling systems; shipyards contend with oxide scale and welding slag in new piping.
2. Core Equipment Cleaning Technologies
2.1 Heat Exchanger Cleaning
Shell-and-tube and plate heat exchangers are extensively used across Yangzhou's chemical and machinery sectors. For shell-and-tube units with predominant CaCO₃ scaling, a composite cleaning agent of HCl and Sulfamic Acid with Lan-826 corrosion inhibitor is recommended, operating at 50–55°C with flow velocity of 0.3–0.5 m/s. Plate heat exchangers, with narrow flow gaps of 2–5 mm, require alternating forward-reverse circulation during chemical cleaning, supplemented by high-pressure water jetting at 40–60 MPa for individual plate flushing. The endpoint criterion is an acid concentration differential of less than 0.1% between inlet and outlet.
| Method | Applicable Equipment | Process Parameters |
|---|---|---|
| Chemical Cleaning (Circulation) | Shell-and-tube, double-pipe exchangers | HCl + Sulfamic Acid, 50–55°C, 0.3–0.5 m/s |
| Chemical Cleaning (Soak + Circulation) | Plate, spiral plate exchangers | Alternating direction circulation, soak 4–6 h |
| High-Pressure Water Jetting | Tube bundles, tube-side of all exchanger types | 40–60 MPa, flow 40–60 L/min |
2.2 Reactor and Vessel Cleaning
Multiple enterprises in the Yizheng Chemical Park operate glass-lined and stainless steel reactors requiring periodic cleaning. Glass-lined reactors must avoid fluoride-containing agents (such as NH₄HF₂) to prevent enamel corrosion; alkaline cleaning with NaOH, Na₂CO₃, and Surfactant via soak-circulation is recommended. Stainless steel reactors respond well to Citric Acid and EDTA composite cleaning, followed by acid passivation to form a protective film. Reactor jacket descaling follows similar principles to heat exchanger cleaning, but the confined jacket space requires circulation pumps with head exceeding 20 m to overcome exhaust difficulties.
2.3 Industrial Pipeline System Cleaning
Yangzhou's cable and machinery enterprises operate extensive networks of circulating cooling water pipes, compressed air lines, and hydraulic oil piping, all requiring regular cleaning. Cooling water pipes, predominantly fouled with CaCO₃ scale and bio-slime, benefit from a combined approach: Sulfamic Acid with inhibitor for chemical circulation, followed by high-pressure water jetting at 60–80 MPa for stubborn deposits. Hydraulic oil piping requires specialized degreasing agents via circulation, with nitrogen blow-drying after cleaning. Newly installed piping must undergo acid cleaning and passivation before commissioning to remove welding scale and rust.
2.4 Shipbuilding Pipeline Cleaning
Yangzhou's riverside shipyards demand high cleanliness standards for vessel piping systems. Fuel oil lines, lubricating oil lines, hydraulic lines, and cooling water lines on new builds all require chemical cleaning and passivation before system commissioning. The standard sequence is: fresh water flushing → alkaline degreasing (Na₂CO₃ + Surfactant, 60–70°C) → fresh water flushing → acid derusting (Citric Acid, 80–85°C) → passivation (NaNO₂ or Na₃PO₄) → drying and sealing. Post-cleaning inspection via borescope verifies particulate residue ≤ 30 mg/m².
3. Cleaning Formulation System
| Fouling Type | Primary Cleaning Agent | Corrosion Inhibitor | Auxiliary Agent |
|---|---|---|---|
| CaCO₃ Scale | HCl 6–8% | Lan-826 | Sulfamic Acid |
| Fe₂O₃ Corrosion | Citric Acid 4–6% | BTA + MBT | EDTA |
| Oil/Carbon Deposits | NaOH 3–5% | Na₂SiO₃ | Surfactant |
| Silicate Scale | NH₄HF₂ 2–3% | Lan-826 | HCl (auxiliary) |
| Mixed Scale | Sulfamic Acid 5–8% | Urotropine | Sodium Molybdate |
4. Service Coverage and Response
We cover all six administrative divisions of Yangzhou: Guangling District, Hanjiang District, Jiangdu District, Yizheng City, Gaoyou City, and Baoying County. Danyang is approximately 80 km from Yangzhou, accessible via the Yangli and Hurong Expressways. Our technical team can reach any location in Yangzhou within 2 hours.
| Area | Key Industries | Response Time |
|---|---|---|
| Guangling / Hanjiang | Machinery, auto parts | 1.5 hours |
| Jiangdu | Machinery, shipbuilding supply | 1.5 hours |
| Yizheng | Fine chemicals, chemical fiber | 1.5 hours |
| Gaoyou | Wire & cable, lighting | 2 hours |
| Baoying | Wire & cable, electronic materials | 2 hours |
Standard workflow: on-site inspection → deposit analysis → solution design → cleaning execution → quality verification. Small equipment cleaning typically completes within 12–24 hours; large system cleaning requires 2–3 days. Emergency response available on immediate dispatch.
5. Local Case Studies
Case 1: Shell-and-Tube Heat Exchanger at a Yangzhou Chemical Plant
Equipment: horizontal shell-and-tube heat exchanger, 180 m² heat transfer area, tube-side medium: circulating cooling water, scale thickness 2–3 mm. Applied HCl + Sulfamic Acid composite cleaning with Lan-826 inhibitor at 52°C for 6 hours circulation. Post-cleaning, the approach temperature recovered from 18°C to the design value of 24°C — a 33% efficiency improvement, yielding annual electricity savings of approximately ¥120,000.
Case 2: Cooling Water Pipeline Network at a Yangzhou Machinery Manufacturer
Total pipeline length ~600 m, diameters DN50–DN150, primarily CaCO₃ scale with iron rust. Applied segmented chemical cleaning with Sulfamic Acid for 4 hours circulation, followed by high-pressure water jetting at 60 MPa for each section. Post-cleaning, flow rate recovered to over 95% of design capacity, with marked improvement in cooling performance.
6. Why Choose Lanxing
- Proximity and Rapid Response: Danyang to Yangzhou via expressway — under 2 hours to any district, immediate dispatch for emergencies
- Extensive Experience: Over 20 years in industrial equipment cleaning, serving chemical, power generation, steel, machinery, and shipbuilding sectors
- Comprehensive Capability: Both chemical cleaning and high-pressure water jetting in-house, enabling flexible combined approaches for diverse fouling types
- Safety and Compliance: Member of the China Industrial Cleaning Association; all operations follow safety protocols; waste is treated per environmental standards
- Free Initial Inspection: Complimentary first site visit with deposit analysis and a customized cleaning proposal
7. FAQ and Recommendations for Yangzhou
Q: How does Yangtze River water affect equipment? With total hardness of 120–160 mg/L, the water is moderately hard. Direct use as cooling water leads to scale deposition: typically 15%–25% efficiency loss within 6–12 months of operation. We recommend chemical cleaning every 12–18 months, or every 8–10 months for high-load equipment.
Q: What distinguishes chemical plant cleaning from general machinery cleaning? Chemical plant equipment often contacts acidic or alkaline process media, producing complex fouling compositions (organic polymers, catalyst residues, etc.) that require deposit analysis before custom formulation. General machinery cooling systems primarily face CaCO₃ scaling with more standardized formulations. Waste treatment also differs — chemical plant wastewater may contain organics requiring classification and separate treatment.
Recommendation: Yangzhou industrial enterprises should establish equipment cleaning logs and develop preventive maintenance plans based on operating hours and water quality monitoring data. Avoid waiting until efficiency drops significantly before emergency cleaning. Regular cleaning not only extends equipment life but also significantly reduces energy consumption — for a shell-and-tube heat exchanger with 200 m² surface area, scheduled cleaning can save ¥80,000–150,000 in annual electricity costs.