Upgrade for safety-critical alarms

Remote monitoring specialist Omniflex has delivered a project with Givaudan to rationalise how the global fragrance and flavours specialist carries out safety-critical monitoring in its UK manufacturing facility in Ashford, Kent. 

The project highlights the growing need for UK manufacturers of all kinds to replace obsolete alarm annunciator panels with modern, networked alarms that are hardwired into potentially hazardous processes.

The project, which began in October 2019, has seen Givaudan replace its fleet of obsolete Highland alarms, many of which have been in place for decades, with a series of OMNI 16 SIL-rated alarm annunciators. These alarms are hardwired directly into sensors in the process and emit light and sound to operators across the plant in the event of an emergency.

The alarms will be used by Givaudan to monitor safety-critical processes in the production of fragrances and oral care flavours. This includes monitoring variables such as flammable atmospheres, oxygen depletion, temperature, well-levels, ventilation, pump faults and extraction processes.

“The site is 50 years old, so we had a lot of legacy alarms fitted across a site that spans an eight-hectare area,” said Stuart Brazil, electrical project manager at Givaudan. “These alarms didn’t have the ability to be networked, so every alarm point had to be individually wired. You can imagine the amount of complexity that created over such a large area, not least the fact that each time a new alarm was added it needed to be individually wired, and the man-hours that went into that.

“With the Omniflex equipment, we now have a safety-critical alarm system that’s fit for purpose,” continued Brazil. “The system is no longer plagued by complexity; it’s responsive, gives us the necessary prioritisation and can be centrally controlled.

“The team at Omniflex has also been brilliant in helping us through the process. Despite social distancing constraints, their engineer successfully carried out the factory acceptance test on-site. This allowed us to do a dry-run and test all the system before it was installed and commissioned.”

“Givaudan approached us following a review of its safety-critical alarm systems,” explained Gary Bradshaw, director at Omniflex UK. “When we surveyed the site, we found that, while some processes were hardwired into obsolete alarm annunciators, other processes were using PLCs and drives to send an alarm signal to a supervisory control and data acquisition (SCADA) system.

“While it’s common for manufacturers to use their control system to display critical alarms on-screen, this can quickly become overwhelming for operators in the event of an emergency, and manufacturers should instead ensure that all critical processes use hardwired alarm annunciators. 

“The regulations relating to the Control of Major Accident Hazards (COMAH) set out guidelines for alarms to minimise operator response times in an emergency. Operators are at higher risk of missing alarms that are not placed in fixed positions as a result of ‘alarm-flooding’ — a condition where alarms appear on the control panels at a rate faster than the operator can comprehend or deal with. This is a significant problem and one which has led to oil refinery explosions in the past.”