Protecting Personnel with Practical Gas Detector Placement

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A pharmaceutical company needed to implement gas detectors at their facility to protect personnel from potential leaks of toxic and combustible gases. aeSolutions evaluated the gas detector placement and number of detectors that would provide the earliest warning to personnel based on the expected dispersion and behavior of specific gas release scenarios.

Challenge

To design a gas detection system for a multitude of uncommon gases and vapors in a pharmaceutical clean environment with the possibility of both indoor and outdoor releases. The goal was to detect a release at a level as low as reasonably possible, taking into account internal ventilation influences on gas releases.

Solution

Computational Fluid Dynamics (CFD) scenario modeling was performed to justify the number and placement of gas detectors. The CFD models helped ensure the effectiveness of the gas detection system and provided an auditable record of the assumptions made (e.g., leak location, leak size, ventilation rate, etc.) that could be referred to and updated throughout the life of the facility

Results

The CFD models revealed some unexpected behaviors from the vapors of concern compared to what might have been reasonably predicted by their physical properties.

CFD modeling revealed:
• Lighter than air gases were pulled downward, and gas detector locations were revised accordingly
• Gas leaks dispersed farther than expected and affected originally unprotected warehouse buildings; therefore, gas detectors were placed on the ventilation intakes of the warehouse
• An ammonia leak from a sphere under pressure dispersed vertically and was not detected by ammonia detectors around the sphere; coverage was augmented by the use of an open path ammonia gas detector aimed across the top of the sphere

The facility owner now has greater confidence that they are protecting their personnel with an optimal number of detectors in the right locations thereby minimizing long-term maintenance costs for the gas detection system. CFD modeling is the best investment for large facilities with specialty gases to ensure gas detectors are appropriately located for optimum performance.

Learn more about our gas detection services

Industry: Pharma

Geography: Pacific Northwest

Unit Operation: Gas Detectors

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