Counterflow Closed Circuit Cooling Tower
The operating principle of the XLN Series is straightforward: air and spray water flow in opposite directions. Ambient air enters through the grille at the bottom or lower side of the tower and rises vertically through the coil, while spray water is distributed from the top and falls downward. The two streams meet in counterflow on the coil surface. This opposing flow pattern ensures that the air encounters progressively cooler water films as it rises, maintaining a high log mean temperature difference (LMTD) and delivering strong heat transfer performance. The coil carries a closed-loop process fluid—softened water, antifreeze, or specialty fluids—which remains isolated from external dust and airborne contaminants, effectively eliminating scale formation and fouling. The tower features vertical air discharge and a compact footprint, making it well suited for installation in space‑constrained areas such as factory floors or rooftops. The casing is fabricated from corrosion‑resistant steel, and the coil can be supplied in stainless steel or copper, allowing users to balance thermal conductivity with corrosion resistance based on specific operating conditions. Specifications Heat capacity: 30 – 2,000 kW Flow rate: 26 – 1,761 gpm / 6 – 400 m³/h Configuration: Counterflow / Axial fan / Induced draft Typical Applications (focus on compact industrial settings and medium‑to‑small equipment cooling): Rubber and plastics industry – cooling for injection molding machines, internal mixers, refiners, open mills, extruders, calenders, vulcanizers, and strainers. Wire and cable – cooling of drawing fluid for wire drawing machines, ensuring precise diameter control and surface quality. Vacuum furnace series – cooling water for vacuum brazing, quenching, hardening, sintering, melting, and annealing furnaces, protecting seals and vacuum systems. Continuous copper/aluminum casting and rolling – temperature control for crystallizers, rolling mills, and lubrication cooling systems. Centralized compressor cooling – cooling circulating water for multiple air compressors. Water‑source heat pump support – providing stable cooling water for heat pumps in commercial buildings and factory HVAC systems. Induction heating and medium‑frequency power supplies – closed‑loop cooling for medium‑frequency furnaces and high‑frequency quenching equipment. Printing and microwave equipment – cooling for dryer rollers and microwave generator water systems. Electro‑hydraulic hammers and electroslag furnaces – cooling hydraulic oil and crystallizer systems. Chemical reactor auxiliary cooling – temperature control for small‑to‑medium batch chemical processes.
How it works?
The counterflow closed-circuit cooling tower operates on three synergistic mechanisms: closed internal circulation, spray external circulation, and counterflow heat exchange. The process fluid to be cooled—softened water, antifreeze, or specialty fluids—circulates in a closed loop within the heat exchange coil, completely isolated from the outside environment, eliminating scaling and contamination. Meanwhile, the overhead spray system evenly distributes water from the collection basin over the outer coil surface, forming a continuous water film that continuously absorbs heat transferred from the fluid inside the coil. Under the suction of the top-mounted fan, ambient air enters through the inlet grille at the bottom or lower side of the tower and rises vertically through the coil bundle, coming into direct counterflow contact with the falling spray water. This arrangement maintains a high log mean temperature difference (LMTD) between the air and the water film along the entire coil height, providing a strong driving force for heat transfer. Evaporation of the spray water removes significant latent heat, while the air simultaneously carries away sensible heat through the temperature difference, achieving efficient cooling. The moist, heated air then passes through the drift eliminator at the top, which removes entrained water droplets before discharge to the atmosphere, preventing drift losses. The cooled spray water falls back into the collection basin for recirculation, while the process fluid returns to the equipment, completing the closed-loop cooling cycle.
Structure & Characteristics
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1 、Heat Exchange Coil:
Process fluid circulates inside the coil in a closed loop, with heat transferring through the tube wall to the external spray water—this is the core of a closed-circuit tower. Standard coils are 304 stainless steel, with options for 316L, copper, or duplex steel. All coils are pressure-tested for leak-proof performance. Multi-layer serpentine layout with optimized tube spacing allows smooth air passage and efficient heat transfer.
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2 、Fan:
The fan drives airflow across the coil and fill media to carry away heat; airflow volume directly affects cooling performance. All units feature special axial fans with nylon or aluminum blades, galvanized steel supports and guards. Motors are IP55-rated, Class F insulation, with optional VFD for energy-saving speed control.
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3 、Spray Pump:
The spray pump draws water from the basin and delivers it to the top distribution system, powering the external circulation loop. Xuelun uses high-performance branded pumps with high flow, low power draw, and quiet operation. Pump bodies and impellers are available in cast iron or stainless steel to suit different water quality conditions.
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4 、Water Distribution System:
The distribution system sprays water evenly over the coil surface to form a continuous film—uniform coverage directly impacts heat transfer efficiency. On counterflow towers, the system sits at the top, using high-capacity ABS basket-type nozzles that resist clogging and are easy to remove for cleaning.
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5 、Air Inlet Louver:
The inlet louver guides air evenly into the tower while blocking debris like leaves, insects, and dust to prevent coil and nozzle fouling. It features PVC fill with a metal frame and is fully removable—simply lift upward and pull outward from the bottom for convenient cleaning.
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6 、Drift Eliminator:
The drift eliminator sits below the fan or at the air outlet, using inertial impingement to capture fine water droplets from the moist air and return them to the basin, reducing water loss. Made of corrosion-resistant PVC, it limits drift loss to under 0.1%.
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7 、Casing:
The casing provides structural support and weather protection for internal components, shielding them from rain, sun, and spray corrosion, while also reducing noise and improving appearance. Constructed from ZAM-coated steel or 304 stainless steel, laser-cut for precision—offering superior corrosion resistance over standard galvanized or FRP shells.
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8 、Collection Basin:
Located at the base, the basin collects spray water and provides a stable suction source for the spray pump. The basin is typically made of the same material as the casing—ZAM-coated steel, with 304 or 316 stainless steel available as upgrades for enhanced durability in demanding environments.
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9 、Base Frame:
The base frame supports the entire tower, transferring weight to the ground and ensuring stable, level operation. Constructed from galvanized channel steel; stainless steel is available as an option for applications requiring additional corrosion protection in humid or chemically aggressive environments.
Basic norm
