High-Capacity 450m² Anodic Protection Sulfuric Acid Cooler CD-AP-450 316L Shell for Extreme Acid Processing

The Carpe Diem CD-AP-450 Anodic Protection Sulfuric Acid Cooler is our flagship high-capacity model engineered for the most demanding sulfuric acid cooling applications in the industry. Featuring an expansive 450m² heat exchange area and purpose-built for 99.5% ultra-concentrated acid service, this shell and tube cooler handles an inlet temperature of 98°C with an outlet target of 60°C at an extraordinary flow rate of 750,000 Kg/h. The CD-AP-450 is distinguished by its all-316L stainless steel construction, with both the shell and tube bundle fabricated from molybdenum-bearing 316L alloy to provide maximum corrosion resistance in the aggressive high-temperature, near-azeotropic acid environment. The tube bundle comprises Φ25 × 2.5 × 7000mm precision-drawn seamless tubes offering superior thermal performance and structural integrity. Before leaving our factory, each CD-AP-450 undergoes an exhaustive multi-stage non-destructive testing program that includes 100% radiographic examination of all pressure-retaining butt welds, ultrasonic thickness mapping of all shell and head plates, liquid dye penetrant inspection of every fillet weld and nozzle attachment, automated ultrasonic testing of tube-to-tubesheet weld seams, and a full helium mass spectrometer leak test of the assembled unit. This uncompromising inspection regime, combined with the most powerful anodic protection system in our product line, makes the CD-AP-450 the definitive choice for world-scale sulfuric acid plants, large metallurgical complex acid systems, and single-train fertilizer complexes where any unplanned cooler downtime would result in production losses measured in millions of dollars per day.

• Full 316L Stainless Steel Construction: Unlike standard models that use a 304L shell paired with 316L tubes, the CD-AP-450 employs 316L stainless steel throughout both the shell and tube circuits. This all-316L approach provides enhanced resistance to the elevated corrosion rates that occur in 99.5% acid at temperatures approaching 100°C, where the passive film stability on 304L can be compromised over extended operating periods.
• Exhaustive Multi-Stage NDT Verification: Our most comprehensive inspection program is applied to every CD-AP-450. The six-stage protocol includes 100% radiography of all butt welds, phased array ultrasonic testing of critical nozzle-to-shell welds, automated fluorescent dye penetrant inspection of all fillet welds, eddy current testing of every individual tube before bundle assembly, helium mass spectrometer leak detection of the complete tube bundle at 1×10&supminus;&sup7; Pa·m³/s sensitivity, and a 60-minute hydrostatic pressure hold test with digital chart recording.
• Industry-Leading 450m² Heat Exchange Capacity: With nearly half a thousand square meters of effective heat transfer surface, the CD-AP-450 is designed to serve as the primary acid cooling stage in world-scale single-train sulfuric acid plants producing over 2,000 metric tons per day. The massive 750,000 Kg/h flow capacity ensures that even the largest acid circulation systems can be served by a single cooler unit, simplifying plant layout and reducing installed cost.
• Heavy-Duty Structural Design: At 17,500 Kg with overall dimensions of Φ1000 × 7900 × 1580mm, the CD-AP-450 is built on a reinforced structural steel cradle with integral lifting trunnions rated for the full assembly weight. Finite element analysis is used to verify that all load-bearing components meet the stress limits of ASME Section VIII Division 1 with comfortable safety margins for transportation and seismic loading conditions.
• Enhanced Anodic Protection for Extreme Conditions: The anodic protection system is configured with redundant current output channels, dual reference electrodes for signal validation, and expanded current density capacity to maintain passive film stability at the extreme acid concentration (99.5%) and elevated temperature (98°C) operating point where the corrosion rate of unprotected stainless steel would be unacceptably high.
• Thick-Wall Tube Construction for Longevity: The Φ25 × 2.5mm tube specification provides a generous 2.5mm wall thickness, offering substantial corrosion allowance beyond that of thinner-walled tubes. This robust design extends the operational life of the tube bundle and provides a safety buffer against localized corrosion that may initiate if the anodic protection system experiences temporary interruptions.
• Rapid Heat Recovery Capability: The combination of high heat exchange area, optimized tube-side velocity, and efficient baffle spacing enables a 38°C temperature reduction at full rated flow, making the CD-AP-450 an effective heat recovery device that can feed pre-heated cooling water to low-pressure steam generators or plant heating systems, improving overall plant energy efficiency.

The CD-AP-450 Anodic Protection Sulfuric Acid Cooler is engineered for the largest and most critical sulfuric acid cooling duties in the global chemical and metallurgical industries. Primary deployment scenarios include world-scale double-contact double-absorption sulfuric acid plants with capacities exceeding 2,000 metric tons per day, where the unit serves as the main absorption tower acid cooler handling the full circulation flow. In large copper smelter complexes processing over one million tons of concentrate annually, the CD-AP-450 provides reliable acid cooling for the gas cleaning and drying tower circuits where acid temperatures can spike during furnace transitions. The unit is also specified for mega-scale phosphate fertilizer complexes integrating sulfuric acid production with phosphoric acid manufacturing, where reliable acid cooling directly impacts downstream phosphoric acid concentration efficiency. Nickel laterite high-pressure acid leach facilities, which consume massive quantities of concentrated sulfuric acid, utilize the CD-AP-450 in their on-site acid regeneration systems. Petroleum refineries operating sulfuric acid alkylation units with capacities above 20,000 barrels per stream day represent another significant application where the cooler handles the critical spent acid regeneration cooling duty. In all these applications, the CD-AP-450's combination of all-316L construction, exhaustive NDT verification, and redundant anodic protection provides the reliability demanded by continuous process operations where unplanned downtime carries extraordinary financial consequences.

The CD-AP-450 is manufactured under the most stringent quality control procedures in our product line, reflecting its role as our premier high-capacity sulfuric acid cooler. All pressure boundary materials undergo triple verification: mill test certificate review against purchase specifications, positive material identification using optical emission spectroscopy, and independent third-party laboratory chemical analysis of a sample coupon from each heat of steel. Welding operations are performed exclusively by senior ASME-certified welders under fully documented welding procedure specifications, with all weld consumables certified and stored in heated quivers to prevent moisture absorption. The comprehensive NDT program is executed by ASNT Level II and Level III certified inspectors and includes radiographic testing of all butt welds with digital image archiving, ultrasonic testing of all nozzle-to-shell full penetration welds, magnetic particle examination of all temporary attachment removal areas, liquid penetrant inspection of all accessible fillet welds, eddy current testing of 100% of tubes before bundle assembly, and a helium leak test with sensitivity verified by a calibrated standard leak. Hydrostatic testing is performed with calibrated digital pressure transmitters and strip-chart recorders providing permanent test records. The anodic protection system undergoes a 72-hour continuous burn-in test and full functional verification including rapid load change simulation. For ocean freight shipment, the completely assembled CD-AP-450 is bolted to a heavy-gauge structural steel shipping frame with robust diagonal bracing. All flange faces are protected with bolted steel blind flanges using full-face PTFE gaskets. The entire assembly is enclosed in a weatherproof vapor-phase corrosion inhibitor wrap with desiccant bags placed inside all nozzle openings. The anodic protection control system, reference electrodes, spare anode assemblies, and special tools are packed in a separate IP65-rated steel shipping container with foam cushioning. Documentation delivered with each unit includes the complete material certification package, all NDT reports with digital radiography files, hydrostatic test chart recordings, helium leak test certificate, anodic protection system factory acceptance test report, dimensional conformance report, surface finish and cleanliness certification, ASME U Stamp Manufacturer's Data Report, pressure equipment directive documentation (where applicable), and comprehensive installation, operation, and maintenance manuals in English with supplementary language versions available upon request.