Tuesday 13th July 2004
Hazard detection specialist Groveley Detection has designed a unique gas sampling system to overcome a problem on a new offshore oil drilling platform at Azerbaijan.
It enables clean samples to be taken from the extremely dirty Shale Shaker HVAC extract duct by combining a Simrad point detector and Groveley's own self-compensating duct probe with a special filter. The sample can be taken, filtered, passed through the gas detector and exhausted back into the duct.
The big advantage will be to reduce maintenance to the gas detector outside the duct as the sample will be filtered before being passed across the gas detector. Simrad's silicon-based IR source has an in-service life of around 60 years, so it will not need to be replaced or recalibrated during its service life. That exceeds all current competing technologies which often have an expected in-service life of only two to four years.
Two systems are currently being installed and a further unit will be delivered over the next few months.
Groveley's managing director Robert Bennet said: "The platform owners approached us to design a specialist application to overcome a classic problem - in most drilling areas mud increases the need for maintenance and cleaning on the gas detector, so we eliminated this by drawing a sample off and passing it through a filter before reaching the gas detector."
Simrad's GD-10P is a fail-safe infrared point detector for use in ducts and is designed for critical applications needing a fast response to low gas concentration within large volumes of air moving at high velocity
Groveley's self-compensating duct probe draws a representative sample from the whole width of a duct, no matter what the flow rate or pressure in the duct. It ensures equal volumes of sample are drawn from each duct sampling point, before combining them prior to introduction to the Simrad detector. At the same time it prevents any large particles being carried by the flow in the duct - which in traditional probes can block sampling points - to reach the detector.
The entire system is designed to run from 24 volts using a built-in inverter, so it only needs a single three-core cable.
Groveley has already supplied gas and smoke aspirators, Simrad GD-10P detectors and self-compensating duct probes to the site.
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