Meat processor enhances fire safety

The causes of fire incidents at meat processing plants can be quite varied, from electrical malfunction, equipment failure and overheating machinery to the combustion of animal fats, oils and other flammable materials. In the event of a fire, the meat processing plant can suffer costly, lengthy production downtime and often cannot reopen for an extended period due to extensive property damage and remediation measures.

Unfortunately, processors that butcher and package meat face unique fire protection challenges due to the nature of the working environment. These factors — namely the presence of smoke, steam, dust, particulates, oil and water vapour — result not only from the butchering, rendering and packaging of high-fat content animal proteins, but also from lubricants and hydraulic oil droplets, exhaust and regular sanitary washdowns. This environmental ‘haze’ can wreak havoc on standard smoke detectors, often causing them to fail, alarm excessively or require excessive maintenance.

“The challenge is finding a means to quickly and accurately distinguish between smoke from an actual fire and the typical airborne particulates in the background during meat processing,” said Jim Deakin, a fire alarm engineering technologist at US business API Systems Integrators.

Resolving a smoke detection challenge

When a meat processing plant in the US sought to add smoke detectors to three refrigerated vacuum pump rooms at the request of its fire insurance company, it faced a difficult task. In the three rooms, pumps used to vacuum seal meat products for distribution were creating an environmental hazard.

The risk insurer and meat processor sought a fire detection system that was fully compliant with NFPA 61: Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities.

“The exhaust was intermingling with water vapour from washdowns in a manner that could hinder the operation of traditional fire detection devices. In addition, there was a visible accumulation of lubricant residue on nearby surfaces near the vacuum exhaust,” Deakin said. “It was clear that traditional smoke detectors would not function properly in this environment.”

To minimise potential losses due to unwanted alarms and provide the best possible long-term detection system, Deakin proposed a solution that involved installing two complementary VESDA smoke detection systems from Honeywell in each room, in what would be a performance-based application.

“One VESDA system [the VLI] will provide an atmospheric reference in each vacuum pump room, minimising unwanted alarms. A second VESDA system [the VLI] will determine when smoke contamination from a fire exceeds the atmospheric reference and then activate the building’s fire alarm,” said Khaleel Rehman, director of development for the advanced detection team at Honeywell.

According to Rehman, a VESDA VLI system uses a piping network to draw in air from the protected area to a central location, which facilitates smoke detector reliability and reduces potential contamination.

With more detailed information to analyse, installers can program the unit to differentiate smoke from other factors that could cause disruptive false alarms. In meat processing plants, airborne dust and particles may be present, which can confuse some systems that incorrectly register them as smoke. In response, the unit’s dust rejection and data analytics is claimed to minimise nuisance alarms by at least three times, compared to similar technologies.

The detector’s high-sensitivity chambers and cumulative sampling can deliver early fire warnings. The detector combines an intelligent filter with an advanced clean-air barrier for optics protection, providing a long detection chamber life without the need for recalibration.

In the second layer of VESDA smoke detection, a VLI unit integrates in an interdependent, cross-zone fashion with the VLI. With this configuration, the VLI determines when smoke contamination from a fire exceeds the initial atmospheric reference. When it does, the unit activates the fire alarm system. The VLI is designed to provide consistent performance throughout its service life, with a technology that uses a clean-air barrier to keep its optical detection chamber components clean.

In addition, a user-initiated feature helps to prevent nuisance alarms by introducing clean air into the detection chamber and taking a reference reading of the chamber background. This reading is then offset against the actual environmental background to maintain consistent, absolute smoke detection.

Used together, the two VESDA smoke detection systems enable meat processors to set alarm thresholds above specific site background contamination levels as a further safeguard against nuisance alarms.

To further enhance the smoke detector, Honeywell is providing a pipe cleaning system designed to blow air and debris out of the VESDA piping network and sample ports. The system is designed to minimise any potential contamination inside the sampling network.

According to Rehman, after successful testing and installation, the fire insurance company that originally initiated the project was happy with the results.

Top image credit: iStock.com/chaikom