BRIDGER SCIENTIFIC heat transfer performance monitoring


The Nature of Fouling Defined –
Fouling in industry is defined as the undesirable accumulation of material on equipment surfaces such that function, performance, efficiency or operation of the equipment is degraded. Some fouling mechanisms are well understood and yield to numerous mediation methods. Others are as wide spread as the ocean, and require site specific strategies for minimization and control. Bridger Scientific develops technologies to aid in the understanding and control fouling phenomena.

Examples of Fouling and its deleterious effects:

Micro biologic growth on heat exchanger heat transfer surfaces (biofilm)

thermal performance loss

Ship hull macrobiological accumulations (macro organic fouling – barnacles)

speed, drag and weight

Calcium carbonate scale on home water heater elements (mineral scale)

premature failure

Plaque on human teeth (biofilm)

bad breath / cavities

Rime ice build up on aircraft wings (clear ice)

reduced lift / crash

Cholesterol build up on human arteries (organic deposit)

heart attack / death

The Interdisciplinary Nature of Fouling – A holistic view
Many different people with various skill sets and objectives are involved with fouling in industry. I’ll speak primarily about electric utility power plants, as that is what I am most familiar with. But the stage is similar for many industries using industrial quantities of water - The actors:

  • The plant operator – wants to operate the plant as requested without limitations or restrictions
  • The regulator – federal or state monitoring of NPDES permit compliance
  • The biologist – protecting the environment by monitoring aquatic organisms and quantifying impacts
  • The performance engineer – monitoring plant thermal performance and calculating efficiency
  • The chemist – monitoring and adjusting the biocide, scale and corrosion inhibitor schedule as required
  • The maintenance foreman – scheduling the work and shutdowns to clean heat exchangers as necessary
  • The accountant – juggling the relative economic costs of water pollution and air pollution
  • The plant owner – wants to maximize profits and productivity
  • The local public – they want jobs, electricity, a clean lake/river/beach/ocean, and skies overhead !

All these people have a vested interest in the plants operation. And all their goals are different and sometimes mutually contradictory. Information must flow between them and somebody must act as the coordinator of their actions. Neglect the needs or desires of anyone of them at your peril! We sell instrumentation that is used to improve the understand of fouling problems for many of these people. And we never know into which direction we will be pulled next – engineering/biology/regulatory compliance…

Numerous methods have been used to control fouling in nature. Early sailing ships applied copper plates to their sides to inhibit marine biological fouling. They also sailed up river from the ocean to expose the attached ocean organisms to fresh water so they would die and fall from the ship to improve speed. It was not until the modern age of wide spread plumbing and sanitation (and high population density) that humanity has had to deal with fouling in a more significant way.

The primary systems we are concerned with are industrial users of cooling water. In the US, a NPDES (national pollution discharge elimination system) permit is required of all water users who take and then discharge large quantities of water to the environment. The permits program, originally started circa 1972 with the clean water act. The permits typically restrict large users of water to discharging water with known toxins above a specific threshold. The bar is changing as our knowledge of the environment and the sensitivity or fate of various chemicals improves. Other nations have similar issues and have instituted similar programs. The greatest motivation for understanding and improved control comes from those areas with high population density and scarce water resources.

A Breakdown by type

  • Biological – Macrobiological (barnicles, mussels, hydroids…)
    Microbiological (biofilms)
  • Mineral Scale - calcium carbonate (inverse solubility scales)
  • Product fouling - petrochemical coking
    milk sterilization/scalding

Bridger Scientific Inc
PO Box 704, 114 State Road B-7
Sagamore Beach, MA 02562
Phone 508-888-6699 Fax: 508-888-5919 or

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