Water Expert Andy Ball: What is meant by scaling or fouling?

What is meant by scaling or fouling?

| 11 Apr 2024 | 11:49

Fouling refers to the accumulation of unwanted material on solid surfaces, most often in an aquatic environment. The fouling material can consists of either living organisms (biofouling) or be a non-living substance (inorganic or organic). Other terms used in the literature to describe fouling include: deposit formation, encrustation, scaling, scale formation, crudding, and deposition. The last four terms are less inclusive than fouling; therefore, they should be used with caution.

Components subject to fouling

The following lists examples of components that may be subject of fouling and the direct effects of fouling:

heat exchanger surfaces – reduces thermal efficiency, increases temperature, creates corrosion, increases use of cooling water

piping, flow channels – reduces flow, increases pressure drop, increases energy expenditure, may create flow oscillations

ship hulls – increases fuel usage, reduces maximum speed

turbines – reduces efficiency, increases probability of failure

solar panels – decreases the electrical power generated

reverse osmosis membranes – reduces efficiency of water purification, increases pressure drop, increases energy expenditure

electrical heating elements – increases temperature of the element, increases corrosion, reduces lifespan

nuclear fuel in pressurized water reactors – axial offset anomaly

injection/spray nozzles (e.g., a nozzle spraying a fuel into a furnace) – incorrect amount injected, malformed jet, component inefficiency, component failure

venturi tubes, orifice plates – inaccurate or incorrect measurement of flow rate

pitot tubes in airplanes – inaccurate or incorrect indication of airplane speed

teeth – promotes tooth disease, decreases aesthetics

Andy Ball
Culligan Tri-County Water Conditioning of Sparta