Fouling is the accumulation of unwanted material on solid surfaces that can consist of living organisms or non-living substances. It occurs on components or systems performing a defined function and impedes that function. There are different types of fouling including macro fouling of debris or marine growth and micro fouling involving scaling, particulate accumulation, corrosion, chemical reactions, or biofouling. Fouling affects components like heat exchangers, pipes, ship hulls, turbines, and membranes by reducing efficiency and increasing pressure drops, temperatures, and energy usage. Methods to control fouling include filters, biocides, inhibitors, flow velocity control, material selection, minimizing dead space, and chemical or mechanical cleaning.

1. FOULING PHENOMENON
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2. DEFINITION
Fouling is the accumulation of unwanted material on solid surfaces
Fouling materials can consist of either living organisms (biofouling) or a
non-living substance (inorganic or organic).
Fouling is usually distinguished from other surface-growth phenomena in
that it occurs on a surface of a component, system, or plant performing a
defined and useful function and that the fouling process impedes or
interferes with this function
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3. Macro Fouling
FOULING TYPE
• Manmade refuse
• Detached internal parts of components
• Tools and other "foreign objects" accidentally left after maintenance
• Marine Growth
Micro Fouling
• Scaling or Precipitation fouling - crystallization of solid salts, oxides, and hydroxides from water solutions
• Particulate fouling - accumulation of particles, typically colloidal particles, on a surface
• Corrosion fouling - in-situ growth of corrosion deposits, for example, magnetite on carbon steel surfaces
• Chemical reaction fouling - decomposition or polymerization of organic matter on heating surfaces
• Solidification fouling - when components of the flowing fluid with a high-melting point freeze onto a subcooled surface
• Biofouling - like settlements of bacteria and algae
• Composite fouling - whereby fouling involves more than one foulant or fouling mechanism
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4. • Heat exchanger – reduces thermal efficiency, decreases heat flux, increases temperature on the hot side, decreases
temperature on the cold side, induces under-deposit corrosion, increases use of cooling water
• Piping – reduces flow, increases pressure drop, increases upstream pressure, increases energy expenditure, may cause flow
oscillations, slugging in two-phase flow, cavitation; may increase flow velocity elsewhere, may induce vibrations, may cause flow
blockage
• Ship hulls – creates additional drag, increases fuel usage, reduces maximum speed
• Turbines – reduces efficiency, increases probability of failure
• Solar panels – decreases the electrical power generated
• RO membranes – increases pressure drop, increases energy expenditure, reduces flux, membrane failure
• Electrical heating elements – increases temperature of the element, increases corrosion, reduces lifespan
• Injection/spray nozzles – incorrect amount injected, malformed jet, component inefficiency, component failure
• Orifice plates – inaccurate or incorrect measurement of flow rate
• Production wells – decreased petroleum production with time; plugging
COMPONENT EFFECTED
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5. COMPONENT EFFECTED
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6. FOULING CONTROL
• Strainer or Filter – to avoid particle or debris entering the component or system
• Biocide injection – Chlorine injection to control microorganism
• Chemical fouling inhibitors – to bonding with chemical fouling
• Flow velocity – increase flow velocity to minimize fouling rate
• Temperature – increasing temperature may increase salt concentration
• Material and surface material – Smooth surface can decrease fouling rate, Copper-alloy is toxic for microorganism
and reduce biofouling
• Minimum dead space – Reduce fouling rate
• Chemical or mechanical cleaning - processes for the removal of deposits and scales
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7. THANK YOU
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