What Is Bac Cooling Tower Distribution Deck

A BAC cooling tower distribution deck is a key part of BAC crossflow cooling towers, sitting directly above the fill and below the hot water basin. It ensures uniform gravity distribution of water across the fill surface.

Here’s a focused, BAC-specific explanation.

1. What Is a BAC Distribution Deck?

The distribution deck is a flat, perforated surface that:

* Supports the spray nozzles

* Distributes water evenly by gravity flow

* Prevents concentrated streams from damaging the fill

* Ensures full wetting of the fill for maximum heat transfer

It replaces pressurized spray piping in crossflow designs.

2. Where It’s Used (BAC Models)

Distribution decks are found in BAC crossflow towers, such as:

* Series V

* FXV

* CXV

> Counterflow BAC towers (FXT, VT closed circuit) do **not** use a distribution deck—they use pressurized spray headers instead.

3. Main Components of the Distribution Deck

3.1 Deck Panels

* Factory-molded panels with precision nozzle holes

* Materials:

 * FRP (fiberglass-reinforced plastic) – common in newer towers

 * Galvanized steel – older designs

* Designed for:

 * Structural load of water

 * Corrosion resistance

 * Easy removal for inspection

3.2 BAC Gravity Spray Nozzles

* Snap-in, large-orifice design

* Low head loss

* Self-cleaning under normal operation

* Even spray pattern matched to fill geometry

Typical features:

* Flow: model-specific (often **3–10 m³/h per nozzle**)

* Operating head: dependent on basin water level

* Material: PP or ABS

3.3 Hot Water Basin Interface

* Water level above the deck controls distribution

* Uniform basin level = uniform flow across deck

* Includes:

 * Weirs

 * Strainers

 * Overflow protection

4. How the Distribution Deck Works

1. Hot water enters the hot water basin

2. Water flows by gravity through deck nozzles

3. Spray pattern spreads water evenly

4. Water cascades down the fill as air flows horizontally

Key requirement: Correct basin water depth—too low causes dry spots; too high wastes pumping energy.

5. Common Problems & Causes

Issue	Likely Cause
Dry fill sections	Low basin water level
Uneven wetting	Missing/damaged deck nozzles
Localized erosion	Nozzle misalignment
Reduced capacity	Scaled or partially blocked nozzles
Deck corrosion	Chemical imbalance or aged materials

6. Inspection & Maintenance

* Inspect deck panels annually

* Remove and flush nozzles during shutdown

* Verify nozzle orientation and locking tabs

* Check deck panel supports for sagging

* Maintain proper water chemistry

7. Replacement & Retrofit Notes

* Deck panels and nozzles must match:

 * BAC tower model

 * Cell size

 * Design flow rate

* Aftermarket decks must maintain:

 * Correct nozzle spacing

 * Correct spray height above fill

* Never mix different nozzle types on one deck

8. BAC Distribution Deck vs Pressurized Spray

Feature	Distribution Deck	Pressurized Spray
Water flow	Gravity	Pumped
Pressure	Very low	Higher
Maintenance	Easy	Moderate
Application	Crossflow	Counterflow