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IN DEPTH: Blocking blazes in the kitchen

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A recent Global Fire and Security Systems fire suppression installation at Manchester airport.

Preventing commercial kitchen fires has to be one of the highest priorities for catering equipment distributors when designing and refurbishing foodservice facilities. But what factors in particular should they consider when taking on these projects?

At Nottingham-based fire suppression specialist, Global Fire & Security Systems, business development manager David Hathaway advised: “The first thing to consider is the use of the kitchen, how many covers it potentially needs to do and what type of food it is going to be preparing, e.g. a football stadium might have 30 kitchens that produce 40,000 portion of chips over two match days a month.

“Clearly a system that isolates an individual kitchen and extinguishes the fire without disrupting the whole event is essential. Open cooking appliances under the canopy (anything that cooks food to the open air) usually require coverage with a kitchen fire suppression system, as per the site’s insurance or FRA requirements. Catering installers should liaise with a fire suppression supplier to determine a location for the system’s enclosures, to ensure that the pipework limitations are not exceeded.”

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Hathaway believes that a further consideration for distributors should be the most efficient and safest way to extinguish the fire and the clean-up afterwards. “By using a system that deploys through the ventilation canopies you can be assured that any fire is detected and extinguished,” he said. “It also pinpoints the exact station that the fire has started and only isolates that particular area.

“The fire suppression manufacturer details specific coverage for all forms of cooking equipment, as there are stringent testing procedures carried out by Underwriters Laboratories, also known as UL 300, to ensure maximum system performance. Whether an integrated fit to a fryer or overhead protection for a griddle, the systems are retrofitted to suit the site’s requirements.”

Global provides Ansul brand fire suppression systems, and Catering Insight posed the same question regarding distributor considerations to Ansul’s manufacturer, Johnson Controls. According to John Hunt, the firm’s account manager for Ansul restaurant systems: “Kitchen staff are not trained fire-fighters, so whilst portable extinguishers can be effective as a backup, and as long as they are a match with the agent of the wet chemical suppression system, they should not be solely relied on to protect commercial kitchens against fire.

“Fire protection needs to be available 24/7 because fires can happen at any time and often when unattended. Therefore it’s important to install an automatic fixed fire suppression system if the worst case scenario should happen. It’s important to consider that all grease vapour-producing appliances are a potential fire risk, not just deep fat fryers. Furthermore, it’s important that any protection method supplied is independently third party tested such as specified by BSEN16282-7.”

Hunt emphasised: “Fire protection is not only the responsibility of dealers and ventilation cleaning companies, it’s the responsibility for the owners and operators also. Ansul recognised this importance when developing the Restaurant Electric Detection (RED) system, allowing cleaning companies to safely isolate the fire suppression when cleaning the ventilation. The RED system helps minimise the potential for grease build-up and simplifies maintenance.”

Over at Nobel Fire Systems, MD Ian Bartle recommended to dealers: “From purely a fire protection perspective, extract routes and directions should be kept to the minimums. The shortest duct lengths with as few bends and changes of direction as possible are a preference. This ensures there are less points on the extract internals where turbulence created by direction change on the extracted airflow can create collection points for entrained fat and grease content.

“Vertical routes are easier to fight fires in but the duct route going through other floors of a building should be avoided wherever possible. This helps to prevent the path of any fire spreading to other parts of a building through non-fire resistant extract duct.”

Noting that another consideration is the placement of hot cooking appliances close to the vents in the extract canopy, Bartle continued: “The canopy itself is designed to extract hot air and in doing so draws in fat- and grease-laden air. As that air passes through the canopy, it impinges on the vents, the cooling and friction, depositing the fat content onto the extract surfaces, creating an ever-increasing fire load as time goes by.

“Appliances that produce high temperatures in their extract such as salamander grills, charcoal or BBQ-type appliances can place a higher heat stress on the grease-laden canopy, taking the grease closer to its auto ignition temperature. Fire companies need to compensate for this elevated temperature by placing heat sensors with a higher reaction temperature so that the fire suppression system isn’t triggered during the normal operational cycle of the cooking process.”

SSS Industrial Doors’ timber stud fire shutter on Warringtonfire’s test furnace.

One available option that may be overlooked during the design process is the use of fire-resistant roller shutters. SSS Industrial Doors is one such manufacturer, with sales and technical representative Thomas J. Rawstron noting: “When a commercial kitchen is being designed, a fire shutter is often the final component to be manufactured and installed. Designed to be compact, offering up to 240 minutes of fire resistance protection, our ‘Flame Armour’ fire shutter is the ideal solution for any commercial application within the food industry.”

He continued: “A fire-resistant shutter provides protection for when the unthinkable occurs, designed to operate when the fire alarm has been triggered, or via a local heat detector(s). A fire shutter can be designed for applications such as servery hatches, doorways or escape routes, providing protection and limiting the spread of a fire.”

SSS Industrial Doors manufactured and tested two ‘Flame Armour’ fire shutters at Warringtonfire’s testing laboratory to the new EN 16034 standard. They were tested originally to a rigid structure (masonry/steel) and then further tested to a flexible structure (timber stud partition) with fire-resistant plaster board. A ‘Flame Armour’ fire shutter can be manufactured and installed to the structural opening with minimal modifications to the existing structure being required.

Rawstron concluded: “Catering equipment distributors should be considering the benefits of designing a commercial kitchen with a fire-resistant roller shutter. Primarily, the fire shutter is designed to ensure the fire is contained, allowing all life to escape and ensuring the fire does not spread throughout the building.”

Tags : ansulfire protectionfire safetyFire suppressionglobal fire & security systemsjohnson controlsnobel fire systemssss industrial doors
Clare Nicholls

The author Clare Nicholls

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