Induced Draft, Single-Flow, Cross Flow Cooling Tower

Core Definition

An Induced Draft, Single-Flow, Cross Flow Cooling Tower is a mechanical cooling tower where:

• Induced Draft: A fan at the top pulls air upwards through the tower.
• Single-Flow: Air enters from one side only of the tower.
• Cross Flow: The flow of air is horizontal and the flow of water is vertical downward, crossing each other at 90° angles.

How It Works (Step-by-Step)

1. Water Distribution: Hot water from the process is pumped to an open gravity distribution basin at the top of the tower.
2. Water Flow: Water flows vertically downward by gravity from the basin through orifices (no nozzles required). It then falls through the fill/packing.
3. Air Flow: Ambient air is pulled horizontally through inlet louvers on one side of the tower by the induced draft fan at the top.
4. Heat & Mass Transfer: In the fill section, the horizontal air stream comes into direct contact with the falling water film, facilitating evaporative cooling.
5. Exit: Cooled water collects in the cold water basin below. The warm, moist air is exhausted vertically out the top by the fan.

Key Components & Their Role in Cross Flow Design

1. Open Gravity Distribution Basin: A key differentiator. A hot water basin at the top with precisely sized holes, allowing water to be distributed by gravity without pressure nozzles. Made of FRP or coated steel.
2. Inlet Louvers (Single Side): Located on one side only to direct air and prevent water splash-out.

1. Fill/Packing: Typically splash-type fill (bars, grids) or film fill. The vertical fill stacks are arranged so water breaks into droplets/film as air passes horizontally through it.
2. Induced Draft Fan: Single axial fan mounted on top of the plenum chamber.
3. Drift Eliminators: Located above the fill and below the fan, they remove entrained water droplets from the exhaust air.
4. Cold Water Basin: Collects cooled water at the bottom.

Advantages (Why Choose This Design?)

• Low Pumping Head Required: Gravity-fed water distribution operates at very low pressure (typically 1-2 psi), reducing pump energy costs.
• Easy Maintenance of Distribution System: The open basin is easily accessible for inspection and cleaning of debris/scale from orifices.
• Handles Dirty Water Better: Larger orifices and splash fill are less prone to clogging from suspended solids compared to pressurized nozzle systems.
• Good Accessibility: The single-flow design leaves one side completely open for access to fill and basin during maintenance.
• Simplicity & Reliability: Simple distribution system with fewer small components (nozzles) to fail.