Cooling Tower Product

Overview

A cooling tower rejects waste heat from a water loop to the atmosphere by evaporating a small fraction of the water. Warm water from a chiller condenser, an engine jacket or a process is sprayed over a large heat-transfer surface while air is pulled through it; as some water evaporates, it carries away the latent heat that cools the rest. This evaporative approach lets a tower cool water to within a few degrees of the ambient wet-bulb temperature, well below what a dry air cooler of similar size could reach, which is why towers anchor the cooling of power plants, refrigeration systems, refineries and large HVAC plants.

The induced-draft counterflow arrangement here pulls air upward against the falling water with a fan at the top, giving even airflow and a compact footprint. The penalty for the efficiency is consumption: water is continuously lost to evaporation, drift and a deliberate blowdown, and that loss must be replaced and chemically managed.

How it works

Hot return water is delivered to the Water Distribution basin at the top of the tower and sprayed through nozzles evenly across the Fill & Drift Eliminators. The fill spreads the water into thin films and droplets over a huge surface area; air drawn upward through it evaporates a little of the water and leaves the rest several degrees cooler, which collects in the cold-water basin of the Structural Shell. Drift eliminators above the spray strip entrained droplets so the exhaust leaves nearly dry. Air enters low through the Air Inlet Louvers, which admit airflow while containing splash-out.

Airflow is produced by the Fan Assembly, a large axial fan turned by the Fan Drive — a right-angle gear reducer driven from a deck-mounted motor through a floating shaft. Cooled water collected in the basin is returned to the system, and on packaged units a Circulation Pump pump lifts basin water back up to the distribution header.

Because evaporation steadily concentrates dissolved solids, water chemistry is actively managed. The Makeup & Blowdown system tops the basin back up through a float makeup valve and bleeds off concentrated water through a relay-driven blowdown valve when a conductivity sensor sees the solids climb. Overseeing the cell, the Control Panel panel modulates fan speed to hold the cold-water setpoint and trips the fan on excessive vibration.