Biofilm Activity Monitoring SystemThe ProblemMicrobiologically Influenced Corrosion (MIC) is a significant degradation mechanism in nuclear and fossil-fueled power plants, refineries, chemical processing, pulp and paper, oil and gas production and distribution, and building and military facilities. Essentially all cooling water and process water applications may be susceptible to MIC. Microbiological fouling, which is always a precursor to MIC, can reduce the efficiency of heat exchangers and fluid distribution systems and can interfere with water-based processes.

MIC most often produces localized corrosion and can lead to rapid penetration of piping, vessels, and heat exchanger tubes. In large facilities MIC costs millions of dollars in downtime, repairs, replacements, and application of mitigation methods.

The most common approach to mitigation of MIC is chemical treatment. Chemical costs for a large process plant are often on the order of $1,000,000 per year. Chemical toxicity is always a concern for plant personnel and the environment. This results in close scrutiny of chemical inventories and effluents by regulators.

The SolutionOur patented system was developed to provide on-line and real-time indication of biofilm activity on typical metallic surfaces. The probe is designed and operated so that microorganisms in the environment will settle on probe surfaces before they settle on heat exchanger tubes or piping.

Probe status is indicated on the integrated electronics enclosure by an LED display (red light/green light).

By closely tracking biofilm activity on the probe, the operator is alerted to the need to treat the system, to assess the effectiveness of a treatment, or to schedule maintenance activities. By monitoring biofilm activity on surfaces very precisely, costly over-treatment can be avoided and chemical treatments can be optimized.

For more information, please contact:877-474-7693877-4SI-POWER

Visit our website at: www.structint.com

Email: info@structint.com

The SystemThe system consists of a probe, its integrated electronics, interconnecting cable, display software, user’s manual, and product support.

The probe is installed into a piping system, heat exchanger water box, cooling tower, side stream, etc. via a 1-inch or 2-inch threaded connection. Special probes can also be built for “hot-tap” type fittings or flow-through applications.

The controller’s electronics apply a potential between the probe electrodes, which creates different local conditions on the electrodes; conditions that cause different microbiological colonies to become established on the positive and negative electrodes and produces an electric current that can be trended. The controller also collects and monitors current data continuously when the applied potential is off. An increasing trend in the current signals the onset of biofilm activity on the probe and alerts the operator to take action to control the biofilm. The effectiveness of the action will be readily apparent in the data that is collected following the action.

System data can be downloaded to the user’s PC. Software is included with the system for analyzing the data and creating detailed trend plots, like the one shown below. The system operates on 110 or 220 VAC and has built-in battery backup power.

Epoxy316L SS

orTitanium

2" NPT 304 SSor PVC

6-Pin Sealed Connector

1.500"

2.25

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Structural Conductor

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Electrodes

is a trademark of Structural Integrity Associates. (US Patents 5,246,560 and 5,356,521, )

Plant Chemist, Dave Brumfield ■ “I am pleased with the information that we are getting on the towers and RO inlet.”

■ “towers are clean and we know how to keep them clean.”

■ “The old ATP’s or other methods could not provide this control.”

■ “we have not used Oxidizing Biocide on the tower since Aug 1, 2006.”

● 2005 cost for bleach and biocide = $186,000● 2006 cost for bleach and biocide = $156,000● 2007 cost for bleach, NO biocide = $138,000● Savings in chemical costs alone is $48,000/year

Gas Fired Plant ■ Stabilized liquid bromine provided excellent control.

■ Biofilm monitoring demonstrated that with proper dosing the same level of control could be achieved with far less of the bromine product.

■ Biofilm and other (e.g., scale) monitoring resulted in >50% reduction in cost with no loss of performance.

■ Subsequent optimizations have produced ~90% reductions in cost.

Small Coal Fired Plant ■ Even though monitoring showed that summer begins in ~February and the plant chlorinates more days per year, it also showed that fewer minutes of chlorination were required per year.

■ Monitoring permitted an optimized chemical treatment, saving the plant $10,000 per year in chemical costs alone.

■ The monitoring project justified an upgrade in biocide delivery equipment (eductor system vs. metering pumps).

■ The upgraded addition system plus monitoring permitted elimination of the brushes and baskets after all.

For more information, please contact:877-474-7693

877-4SI-POWER

Visit our website at: www.structint.com

Email: info@structint.com

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