Drift eliminators
Drift is treated water leaving the tower as droplets in the air stream. It costs you make-up water and chemicals, deposits salts on everything downwind, and is increasingly a permit issue rather than a housekeeping one.
Understanding the component
Drift eliminators sit in the leaving air stream and force it to change direction several times. Water droplets, being much denser than air, cannot follow the turns; they strike the eliminator surface, coalesce and drain back into the tower. Air carries on.
Cellular eliminators bond sinusoidal corrugations to mating structural waves to form closed cells, typically forcing three distinct changes of direction. They give the highest removal efficiency and nest or interlock with adjacent modules to stop air bypassing between them.
Blade eliminators assemble sinusoidal blades into modules with end caps. They give up some efficiency for a lower air pressure drop, which on a fan-power-limited tower can be the right trade.
Drift is quoted as a percentage of circulating water flow. Original equipment on an older tower might be 0.02% or worse; current cellular eliminators achieve figures an order of magnitude better. That is the difference between a visible plume with deposition on nearby plant and cars, and neither.
We supply components for cooling towers from every manufacturer, including towers whose original makers no longer exist. If it is on your tower, we can identify it.
What actually goes wrong
These are the failures we find in the field, roughly in order of how often we find them. If you recognize one, we can usually tell you what to check next over the phone.
| Failure | What it means |
|---|---|
| Displaced or missing modules | The commonest fault by far. Any gap is a direct bypass, and a small percentage of open area destroys most of the eliminator's benefit. |
| Fouling and scaling | Deposits close the cells, raise pressure drop and add weight until the modules sag. |
| Sagging and distortion | PVC creeping under its own weight and deposit loading, especially where support spacing was marginal to begin with. |
| Embrittlement | UV exposure at the top of the pack and chemical attack from aggressive water or heavy oxidizer dosing. |
| Support corrosion | The eliminators are fine and the steelwork holding them is not. |
Manufacturers and product lines
We are independent, so the recommendation follows your tower, your water and your duty rather than a single manufacturer's catalog.
Brentwood Industries
CDX-80 and CDX-150 cellular eliminators for ultra-low drift loss, designed to nest and interlock so there is no bypass between modules, in UV-protected PVC. Also D-15 cellular eliminators combining high removal efficiency with very low pressure drop in 10 and 15 mil sheet, and blade eliminators in a range of densities and configurations.
C.E. Shepherd
The DRU Drift Reduction Unit in UV-protected PVC, combining formed and flat sheets: DRU 1.5 uses a 1.5" flute width with 15 mil formed sheet and 30 mil flat sheet.
Marley
Replacement eliminators for the original lines.
Names you may find on the nameplate
Including lines that are no longer current. Many of the towers we work on are thirty to fifty years old, and identifying the modern equivalent of a discontinued component is part of the job rather than an obstacle to it.
- Brentwood CDX-80
- Brentwood CDX-150
- Brentwood D-15
- Shepherd DRU
- Marley
What we would tell you on the phone
Integral-eliminator fill is an option.
Some film fills incorporate an integral louver and eliminator in the fill pack itself, which reduces installed height and the number of separate components. Worth considering where headroom is tight.
Fit them properly or do not bother.
Eliminator performance is dominated by installation quality: full coverage, correct nesting, no gaps at walls, partitions or penetrations. This is a component where careless installation wastes the entire purchase.
Pressure drop costs fan power.
A higher-efficiency eliminator generally means more pressure drop and therefore more fan horsepower. On a tower already short of air, that trade-off needs to be evaluated rather than assumed.
Usually replaced or inspected at the same time
Fill
Film and splash fill for counterflow and crossflow towers, including fouling-resistant grades: Brentwood and C.E. Shepherd.
View componentNozzles
Gravity-flow basin nozzles and pressurized spray nozzles for crossflow and counterflow distribution: Fisher, Dek-Spray and C.E. Shepherd.
View componentFan stacks
FRP fan cylinders and velocity-recovery stacks in Class I, II and III fire ratings: Midwest, Polymer Fabrication and BAC · Baltimore Aircoil.
View componentCasing & louvers
FRP casing in 4.2 corrugated and 5.33 V-Beam profiles, and inlet louvers. Fire rated panels available with UL flame spread of 25 or less.
View componentSend us the nameplate and we will identify it
The fastest route to a correct quote is a photograph of the nameplate and of the component in place. Model numbers get superseded and drawings go missing; photographs do not lie.
- Phone
- (713) 643-0691
- Shop & office
-
3811 Cedar Blvd Ste A
Baytown, TX 77523