Concentrated Sulfuric Acid Shell Tube Exchanger CD-AP-120 120m2 Area 316L Tube

The Carpe Diem CD-AP-120 Concentrated Sulfuric Acid Shell and Tube Heat Exchanger is a versatile mid-capacity solution engineered for reliable continuous cooling of 96 percent concentrated sulfuric acid in fertilizer production, chemical synthesis, and metal processing operations. Built around a 304L stainless steel shell housing a high-performance 316L stainless steel tube bundle, this 120 square meter heat exchanger delivers consistent thermal performance while the integrated anodic protection system maintains corrosion-free operation throughout the entire acid-wetted surface area. With a design capacity of 150,000 kilograms of acid per hour cooled from 69.3 degrees Celsius inlet temperature down to 50 degrees Celsius outlet temperature, the CD-AP-120 occupies an optimal position in the product range for medium-throughput acid plants and intermediate cooling stages in multi-stage cooling circuits. The shell diameter of 650 millimeters and overall length of 7,000 millimeters provide a balanced combination of thermal duty capability and installation footprint that integrates smoothly into existing plant pipe racks and equipment layouts. Each Φ19×2.0×6000 mm tube is individually expanded into the tube sheets using precision mechanical rolling techniques, creating joints that maintain their integrity through decades of thermal cycling and remain fully resistant to the crevice corrosion mechanisms that compromise welded joints in concentrated acid service.

• 304L Shell with 316L Tube Material Combination: The 304L stainless steel shell provides excellent structural integrity and external corrosion resistance at a cost-effective price point, while the 316L stainless steel tube bundle delivers the enhanced molybdenum-alloyed corrosion resistance required for direct contact with 96 percent sulfuric acid at elevated temperatures. This strategically optimized material pairing maximizes value without compromising critical performance characteristics.
• Reliable Anodic Protection System: The integrated anodic protection controller continuously monitors and adjusts the electrochemical potential applied to all internal acid-wetted surfaces, maintaining each surface within the optimal passive potential range where corrosion rates are reduced to less than 0.1 millimeter per year. The system includes built-in reference electrodes, auxiliary cathodes, and a controller with local display and remote communication capability.
• Precision Tube-to-Tube Sheet Sealing: All 316L tubes are mechanically rolled and expanded into the 304L tube sheets using controlled-torque expansion equipment that ensures consistent joint tightness across every tube position. This expanded joint technology eliminates the heat-affected zone weaknesses and residual stress concentrations inherent in welded tube joints while providing a positive mechanical seal resistant to both pressure and thermal loads.
• Mid-Range Capacity Optimization: The 120 square meter exchange area and 150,000 kilogram per hour flow capacity make the CD-AP-120 the ideal choice for sulfuric acid plants with daily production rates between 800 and 1,500 metric tons. The sized-right design avoids the capital expenditure waste associated with oversized equipment while providing sufficient thermal margin for production rate increases and seasonal cooling water temperature variations.
• Balanced Hydraulic Design: Computational fluid dynamics modeling has been applied to optimize the shell-side baffle spacing and tube pitch, ensuring uniform flow distribution across the entire tube bundle while maintaining shell-side pressure drop within acceptable limits. This balanced design approach maximizes heat transfer coefficients without introducing flow-induced vibration risks that could lead to premature tube failure.
• Turnkey Instrumentation Package: Each CD-AP-120 includes factory-installed temperature sensors at acid inlet and outlet connections, differential pressure transmitters across both the acid and cooling water circuits, and potential monitoring ports for the anodic protection reference electrodes. All instrument signals are terminated in a weatherproof junction box for straightforward field wiring to the plant control system.

The CD-AP-120 is ideally suited for intermediate acid cooling in single-contact single-absorption and double-contact double-absorption sulfuric acid plants with production capacities of 800 to 1,500 metric tons per day. Typical installation locations include the drying tower acid cooling circuit where 96 percent acid absorbs moisture from the incoming process air stream and must be continuously cooled before recirculation, and the intermediate absorption tower circuit where acid temperature control directly influences SO3 absorption efficiency and final product quality. Beyond core sulfuric acid production, the CD-AP-120 serves effectively in phosphoric acid plants where sulfuric acid is used for phosphate rock digestion and requires temperature-regulated supply, in caprolactam manufacturing processes where concentrated acid is used as a catalyst, and in non-ferrous metal leaching operations where acid temperature control determines copper and nickel extraction kinetics. The moderate size and weight of 5,500 kilograms also make the CD-AP-120 suitable for containerized acid cooling modules deployed at remote mining and mineral processing sites.

Each CD-AP-120 cooler is dispatched in naked packing with a welded steel protective frame that provides structural support during lifting, transport, and temporary storage. All nozzle flanges are fitted with bolted protective covers incorporating desiccant breathers, and the tube side and shell side internals are pressurized with dry nitrogen to maintain a controlled internal atmosphere throughout transit and storage. Our comprehensive quality assurance protocol includes 100 percent radiography of all longitudinal and circumferential shell welds, dye penetrant inspection of all nozzle-to-shell connections, pneumatic leak testing of the complete tube bundle at 0.5 MPa, hydrostatic shell-side pressure testing at 1.5 times the design pressure, and anodic protection system functional testing with documented potential mapping across all protected zones. The unit ships with a full documentation dossier containing material certificates per EN 10204 Type 3.1, weld maps and NDE reports, pressure test certificates, surface condition reports, and detailed operating manuals covering both the heat exchanger and the anodic protection subsystem. Carpe Diem provides 24-month warranty coverage and maintains a global network of field service engineers capable of providing on-site commissioning support, operator training, and preventive maintenance planning.