Scanner Systems

Plant Integrity and Thermal Mapping Scanners

Rowan Technologies patented scanner systems monitor corrosion/erosion rates and/or thermal characteristics such as heat flux, directly on sections of industrial plant. Also, more specialised systems may be used to monitor crack growth.

The systems use arrays of sensors, directly attached to plant surfaces, and are capable of mapping large areas, or be used for monitoring smaller, localised areas. They are non-intrusive, as the item of plant itself becomes the 'sensor', avoiding the requirement for probe entry ports, especially important where pressure vessels are concerned.

The high-accuracy corrosion/erosion monitoring hardware has evolved from the well-established electrical resistance technique where thinning of a metal increases its measured electrical resistance. However, this measured resistance is also temperature dependent and the scanner has the ability to simultaneously measure temperatures and resistances to a high precision, allowing this temperature dependency to be effectively nulled out. Measurements are performed at, and between sensor locations in a pre-defined sequence (i.e sensor arrays are 'scanned') to allow full surface maps to be produced. The systems allow parameters such as metal loss, corrosion rate, remaining thickness and time-to-replacement to be automatically calculated and mapped.

Typical map showing the effect of weld overlay in reducing the corrosion rates on boiler fireside tube walls

A specialised version of the scanner technology has been developed for use on an Electric Power Research Institute (EPRI) sponsored project in the USA. The system was designed to detect crack growth on weld-overlaid boilers tubes and this was installed on the supercritical Unit 3 boiler at PPL's Brunner Island power station in March 2007.

Illustration of the influence of crack propagation on the flow of current through a plant wall

The thermal monitoring hardware can operate independently of electrical resistance measurements to provide thermal mapping on a real time basis, either as surface temperatures or heat flux. Dedicated thermal monitoring systems are available, where plant integrity monitoring is not a requirement.

Maps showing the effect of sootblowing on boiler wall temperature

The scanner systems take two forms: either as Fixed Systems for continuous on-line monitoring where all hardware remains in place for the duration of the monitoring, or as Portable Systems for periodic monitoring (a recent development) where the control and data acquisition hardware is easily transported (or hand-carried) from one monitoring location to another for periodic measurements.

The scanners have many possible applications including oil and gas pipelines, refinery processess, incinerators, furnaces and nuclear processess.

Key Benefits

Direct, on-line monitoring of corrosion rates
Direct, on-line monitoring/mapping of temperatures and heat flux
Non-intrusive: no requirements for probes or probe insertion ports
Simple installation: for 2-D mapping, a matrix of simple connections is used.
Maintenance free at (remote) monitoring locations
Increased confidence in plant operation and efficiency over extended time periods.

Key Features

Monitoring and mapping of corrosion/erosion, remaining thickness etc in high and low temperature environments
Real-time thermal mapping
Fixed or portable systems
Can be integrated into plant monitoring systems
Robust yet sensitive instrumentation
Systems adaptable and expandable to suit individual requirements.
Measures both short and long term trends.
Well proven electrical resistance measurement technology
On-line two dimensional mapping of surface temperatures and heat flux data from boilers, incinerators and other high temperature industrial plant. Using this system, the operation of the plant may be optimised.



Home Corrosion Protection and Conservation Monitoring of Industrial Plant Services Research and Development Publications Contact Us System data logger and control unit Metal loss on a 14m by 10m section of boiler tube wall Cross section of circumferential crack in weld overlay boiler tubing Weld overlay boiler tube cross section and external circumferential cracking of the overlay

		Scanner Systems
		Plant Integrity and Thermal Mapping Scanners Rowan Technologies patented scanner systems monitor corrosion/erosion rates and/or thermal characteristics such as heat flux, directly on sections of industrial plant. Also, more specialised systems may be used to monitor crack growth. The systems use arrays of sensors, directly attached to plant surfaces, and are capable of mapping large areas, or be used for monitoring smaller, localised areas. They are non-intrusive, as the item of plant itself becomes the 'sensor', avoiding the requirement for probe entry ports, especially important where pressure vessels are concerned. The high-accuracy corrosion/erosion monitoring hardware has evolved from the well-established electrical resistance technique where thinning of a metal increases its measured electrical resistance. However, this measured resistance is also temperature dependent and the scanner has the ability to simultaneously measure temperatures and resistances to a high precision, allowing this temperature dependency to be effectively nulled out. Measurements are performed at, and between sensor locations in a pre-defined sequence (i.e sensor arrays are 'scanned') to allow full surface maps to be produced. The systems allow parameters such as metal loss, corrosion rate, remaining thickness and time-to-replacement to be automatically calculated and mapped. Typical map showing the effect of weld overlay in reducing the corrosion rates on boiler fireside tube walls A specialised version of the scanner technology has been developed for use on an Electric Power Research Institute (EPRI) sponsored project in the USA. The system was designed to detect crack growth on weld-overlaid boilers tubes and this was installed on the supercritical Unit 3 boiler at PPL's Brunner Island power station in March 2007. Illustration of the influence of crack propagation on the flow of current through a plant wall The thermal monitoring hardware can operate independently of electrical resistance measurements to provide thermal mapping on a real time basis, either as surface temperatures or heat flux. Dedicated thermal monitoring systems are available, where plant integrity monitoring is not a requirement. Maps showing the effect of sootblowing on boiler wall temperature The scanner systems take two forms: either as Fixed Systems for continuous on-line monitoring where all hardware remains in place for the duration of the monitoring, or as Portable Systems for periodic monitoring (a recent development) where the control and data acquisition hardware is easily transported (or hand-carried) from one monitoring location to another for periodic measurements. The scanners have many possible applications including oil and gas pipelines, refinery processess, incinerators, furnaces and nuclear processess. Key Benefits Direct, on-line monitoring of corrosion rates Direct, on-line monitoring/mapping of temperatures and heat flux Non-intrusive: no requirements for probes or probe insertion ports Simple installation: for 2-D mapping, a matrix of simple connections is used. Maintenance free at (remote) monitoring locations Increased confidence in plant operation and efficiency over extended time periods. Key Features Monitoring and mapping of corrosion/erosion, remaining thickness etc in high and low temperature environments Real-time thermal mapping Fixed or portable systems Can be integrated into plant monitoring systems Robust yet sensitive instrumentation Systems adaptable and expandable to suit individual requirements. Measures both short and long term trends. Well proven electrical resistance measurement technology On-line two dimensional mapping of surface temperatures and heat flux data from boilers, incinerators and other high temperature industrial plant. Using this system, the operation of the plant may be optimised.