Stainless Steel Spiral Coil Tube — Liquid-Liquid Non-Homogeneous Reactor Grade
Product Overview
The Stainless Steel Spiral Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a precision-engineered tubular product specifically designed for use in liquid-liquid non-homogeneous spiral coil tube reactors (Liquid-Liquid Non-Homogeneous Spiral Coil Tube Reactor, LLCR). This product exploits the unique hydrodynamic characteristics of spiral coil geometries to achieve superior phase dispersion, interfacial renewal, and mass transfer efficiency in immiscible or partially miscible liquid-liquid reaction systems. The coil tube serves as the core heat exchange and reaction vessel element, where the curvature-induced Dean vortices dramatically enhance turbulent mixing between the continuous and dispersed phases, thereby reducing the characteristic dispersion time and improving overall reactor performance.
Wenzhou Jixing Metal Materials Co., Ltd has integrated advanced metallurgical knowledge with reactor engineering requirements to deliver coil tubes that meet the stringent demands of multiphase chemical processing, including pharmaceutical synthesis, fine chemical manufacturing, and environmental treatment applications.
Material & Properties
Base Material
The coil tube is fabricated from high-purity austenitic stainless steel, with the primary grade being AISI 316L (UNS S31603), selected for its exceptional corrosion resistance, mechanical integrity, and compatibility with aggressive chemical media. Alternative grades including AISI 304L (UNS S30403) and AISI 321 (UNS S32100) are available upon request for specific application requirements.
Key Metallurgical Properties
- Corrosion Resistance: The addition of molybdenum (2.0–3.0 wt.%) in AISI 316L provides outstanding resistance to pitting and crevice corrosion, particularly in chloride-containing environments encountered in liquid-liquid reaction media.
- Mechanical Strength: Minimum tensile strength of 485 MPa with elongation ≥ 40% ensures the tube maintains structural integrity under cyclic pressure loading and thermal fatigue conditions inherent to reactor operations.
- Thermal Stability: Suitable for continuous operation in temperature ranges from −196°C to 870°C, accommodating exothermic and endothermic reaction conditions without significant mechanical property degradation.
- Weldability: Low carbon content (≤ 0.03% C) minimizes intergranular corrosion susceptibility, ensuring reliable welding performance for coil-to-header connections and repair procedures.
- Surface Quality: Electropolished or passivated inner surfaces with roughness Ra ≤ 0.4 μm reduce fouling tendency and facilitate CIP (Clean-In-Place) protocols critical for pharmaceutical and food-grade applications.
Specifications
| Parameter | Specification | Unit |
|---|---|---|
| Outer Diameter (OD) | Φ6 – Φ50 (customizable) | mm |
| Wall Thickness | 0.5 – 3.0 | mm |
| Coil Diameter (Center-to-Center) | 100 – 2000 | mm |
| Coil Pitch | 10 – 100 | mm |
| Coil Length | 5 – 100 (customizable) | m |
| Material Grade | AISI 316L / 304L / 321 | — |
| Surface Finish | Electropolished, Ra ≤ 0.4 μm | — |
| Maximum Working Pressure | Up to 4.0 | MPa |
| Operating Temperature Range | −196 to +870 | °C |
| Standard | ASTM A213 / ASME SA-213 | — |
| Tolerance (OD) | ±0.05 mm | — |
| Tolerance (Wall Thickness) | ±10% | — |
| End Treatment | Plain, Beveled, or Threaded | — |
Manufacturing Process
The production of Wenzhou Jixing's spiral coil tubes follows a rigorously controlled multi-stage manufacturing workflow designed to ensure geometric precision, metallurgical homogeneity, and surface integrity:
- Raw Material Procurement & Verification: Stainless steel seamless tube blanks conforming to ASTM A213 standards are sourced from certified mills. Each batch undergoes spectroscopic analysis (OES, Optical Emission Spectroscopy) to verify chemical composition, along with mechanical testing including tensile and hardness measurements.
- Heat Treatment & Annealing: Incoming tubes undergo solution annealing at 1050–1100°C followed by controlled water quenching to achieve a fully austenitic microstructure, eliminating residual stresses from prior cold-working operations.
- Precision Forming & Coiling: Using computer-controlled cold coiling machinery, the straight tube is wound into the specified spiral geometry with exact control over coil diameter, pitch, and helix angle. The forming process employs progressive die reduction to prevent wall thinning, ovalization, or surface cracking. Finite Element Method (FEM) simulation guides the tooling design to optimize the forming window.
- Stress Relief: Post-forming stress relief annealing at 870–900°C eliminates residual stresses introduced during coiling, ensuring dimensional stability and preventing stress corrosion cracking (SCC) in service.
- Surface Treatment: Electropolishing removes surface contaminants, decarburized layers, and micro-roughness, producing a smooth, chemically passive inner surface. Final passivation with nitric or citric acid solutions establishes a protective chromium oxide film.
- Quality Inspection: Comprehensive inspection includes dimensional verification (caliper, CMM), hydrostatic pressure testing at 1.5× working pressure, visual and dye penetrant examination of weld joints, and eddy current testing for wall thickness uniformity.
- Coil Bundling & Packaging: Finished coil tubes are secured with stainless steel strapping, wrapped in moisture-proof protective film, and packaged in export-grade wooden crates or steel containers for safe transportation.
Applications
Primary Application: Liquid-Liquid Non-Homogeneous Reactors
The defining application of this product lies in liquid-liquid non-homogeneous spiral coil tube reactors, where the spiral geometry generates Dean vortices that fundamentally alter the dispersion behavior of immiscible liquid phases. Key performance advantages include:
- Enhanced Phase Dispersion: The helical flow pattern produces secondary Dean vortices perpendicular to the main flow direction, effectively reducing droplet size of the dispersed phase and increasing interfacial area by 3–5× compared to straight-tube reactors of equivalent length.
- Reduced Dispersion Time: Characteristic dispersion time is shortened significantly, enabling continuous-flow operation with residence time distributions (RTD) approaching ideal plug flow, which is critical for product selectivity in parallel or consecutive reactions.
- Improved Heat Transfer: The enhanced turbulence simultaneously improves heat transfer coefficients (by 2–3×), enabling efficient temperature control of exothermic or endothermic reactions within the narrow thermal windows required for high selectivity.
- Scalability: The modular coil design facilitates scale-up from laboratory to industrial production through number-up strategies (multiple coils in parallel) without compromising mixing characteristics.
Additional Applications
- Pharmaceutical Intermediate Synthesis: Continuous-flow production of APIs (Active Pharmaceutical Ingredients) requiring precise control of biphasic reaction conditions.
- Fine Chemical Manufacturing: Liquid-liquid extraction, emulsion polymerization, and microemulsion synthesis.
- Heat Exchangers: Compact spiral coil heat exchangers for process cooling and heating in chemical plants.
- Environmental Treatment: Wastewater treatment reactors employing liquid-liquid mass transfer for pollutant degradation.
- Food & Beverage Industry: Homogenization and pasteurization systems requiring hygienic-grade stainless steel coil components.
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework ensuring product conformity with international standards:
- ISO 9001:2015 — Quality Management System certification ensuring consistent process control and continuous improvement.
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to sustainable manufacturing practices.
- ASTM A213 / ASME SA-213 — Conformance to American standards for seamless austenitic stainless steel boiler, heat-exchanger, and similar heat-transfer service tubes.
- GB/T 14976 — Chinese national standard for seamless stainless steel tubes for fluid transport, ensuring domestic regulatory compliance.
- EN 10216-5 — European standard for seamless stainless steel tubes for general applications.
- Pressure Vessel & Piping Compliance: Products can be certified for use in pressure vessels and piping systems per ASME Section IX (Welding Qualifications) and ASME B31.3 (Process Piping).
- Third-Party Inspection: Available upon request — SGS, Bureau Veritas, or TÜV inspection and material certification for critical applications.
Unique Selling Points: Wenzhou Jixing Metal Materials Co., Ltd differentiates its spiral coil tube products through the integration of reactor engineering expertise with precision metallurgical manufacturing. The company's deep understanding of liquid-liquid non-homogeneous reaction hydrodynamics — informed by research into spiral coil dispersion characteristics — enables the design and production of coil tubes optimized not merely as passive containers, but as active components that enhance reaction kinetics, mass transfer, and thermal management. This application-driven design philosophy, combined with rigorous quality control and material certification, positions the product as a premium solution for demanding multiphase chemical processing applications.