Aging of Cooling Tower Filler? Causes And Solutions

Cooling tower filler is the "chip" of heat exchange, but it is often overlooked. Once it ages, a 2-3℃ increase in the outlet water temperature and a 15% surge in power consumption are just the beginning. The real trouble lies in the clogging of the condenser by debris and the high-pressure tripping of the main unit. If you want to cut your losses in advance, first figure out "why you age" and "how to save yourself".

I. Cooling Tower Filler Four Major Drivers of Aging

Cooling Tower Filler:Double attack from ultraviolet rays and high temperatures

The outdoor tower top has no shading. The PVC packing material has been broken by ultraviolet rays for a long time, and the surface loses its luster first and then cracks. If the inlet water temperature remains above 50℃ all year round, the glass transition temperature of the material will be broken, and the sheet will shatter at the slightest pinch.

Cooling Tower Filler:"Slow corrosion of water quality

When the hardness of the circulating water is greater than 300 mg/L, calcium and magnesium ions form scale larger than 2 mm on the surface of the packing, adding a heating resistance of 0.8 m²·K/W, and the heat dissipation efficiency drops by 30% directly. Acidic ions (Cl⁻, SO₄²⁻) can also seep in through the cracks, accelerating embrittlement.

Cooling Tower Filler:"Internal digestion" of biofilms

Algae and bacteria treat the filler as a "house", and the organic acids they secrete decompose the PVC plasticizer, causing the sheet to powderize and flake off. The green biofilm has thickened to 1mm, which is equivalent to putting on an insulating coat for the filler.

Cooling Tower Filler:Mechanical fatigue

The belt of the cross-flow tower is loose → the blade speed is uneven → the airflow impacts the edge of the packing. When the frequency reaches 20 Hz, micro-cracks appear at the fixed points of the sheet material. After three years, they expand into through seams and eventually collapse and clog the water distributor.

II. Cooling Tower Filler Quickly Determine "Whether It's Time to Change"

On site, all you need to do is "look, pinch and measure"

Look - The color of the crack changes from white to dark yellow, and the crack density is greater than 20 per square meter.

When bent 180°, a brittle cracking sound occurs.

Measurement - Under the same working conditions, the outlet water temperature is 2℃ higher than the design value and remains so for one week. If any one of these conditions is met, aging failure can be determined.

III. Cooling Tower Filler Four Practical Actions to Extend Your Lifespan

Cooling Tower Filler:Pre-treatment of water quality

Install a bypass sand filter and ion exchange to control the hardness below 150 mg/L. Add 50 ppm of non-oxidizing algaecide monthly to inhibit biofilm.

Cooling Tower Filler:Sunshade + heat preservation

Laying black sunshade nets at the top of the tower can reduce ultraviolet rays by 90%. During the hot season in the south, a 30mm insulation board is added to the water collection tray to lower the ambient temperature in the packing area by 5-7℃, extending the service life of PVC from 3 years to 5 years.

Cooling Tower Filler:Low-impact cleaning

When the scale thickness is less than 1mm, soak in a 5% citric acid circulation for 4 hours, neutralize the acid and base, and then rinse. High-pressure water guns are prohibited from sweeping directly to prevent water flow above 0.4 MPa from "breaking" the sheet material.

Cooling Tower Filler:Material upgrade

When the influent temperature exceeds 55℃ or in coastal salt spray environments, PP+ glass fiber packing (with a temperature resistance of 80℃ and a salt spray resistance of ≥1000 hours) can be used instead. Although the initial investment is 30% higher, the service life can be doubled to 8-10 years.

IV. Cooling Tower Filler "First Aid" Procedures after Aging

① Shut down the machine →② Pull out the pieces for random inspection →③ Weigh the crushed materials (replace the entire tower if the weight is greater than 5kg) →④ Select new material pieces with a thickness of 0.4mm and a density of ≥ 1.45g /cm³→⑤ Seal the edges with silicone strips during installation to prevent water from flying. The cost of a single material replacement accounts for approximately 15% of the entire tower's construction cost, but it can restore 95% of the heat dissipation capacity. The period during which electricity costs are saved is generally less than one year.

The cooling tower filler material should not be replaced only when it is worn out, but when it reaches its service life. Make the three things of water quality, shading and cleaning into an annual plan, and the three major killers of ultraviolet rays, scale and biofilm will have no way to escape. When the critical point is reached, switch to new materials without hesitation and don't let the fragments "attack" the main unit.