Fire safety: In hot pursuit of secure fire detectors
Thanks to the high-tech research at Siemens in Zug, Switzerland – where fire alarm systems are developed and tested in the brand-new, on-site FireLab – fire detectors reliably protect people and buildings.
On the 28th of October 2016 the Royal Clarence in Exeter fell victim to the flames. Early that morning a gigantic fire broke out in England’s oldest hotel, and 120 firefighters were dispatched to the scene. But their attempt to extinguish the fire was useless. The Royal Clarence, together with many neighboring buildings, burned down to the foundation walls. A sad event – but not a rare one: worldwide, every twelfth hotel is badly affected by fire. And in Great Britain alone, fire destroys at least seven historical buildings a month, among them historical hotels like the Royal Clarence.
False alarms are a major problem in building security and involve high costs. Siemens can solve this problem with state-of-the-art technology.Mario Kahlert, Head of Fire Safety
But fires aren’t the only problem: often fire alarms – in historical as well as in modern buildings – turn out to be false. According to one Dutch study, this happens in up to 86 percent of all cases. In 2012 some 312,000 alarms occurred in the United Kingdom that later proved to be false alarms. In that same year, the Swiss Fire Service Association counted more than 17,000 false alarms and the City of Munich dispatched firefighters 4,757 times to no purpose. “False alarms are a major problem in building security and involve high costs. Siemens can solve this problem with state-of-the-art technology,” says Mario Kahlert from Siemens. The Head of Fire Safety’s promise: “Siemens guarantees: no more false alarms!”
Going through fire
Siemens has been researching and working hard to fulfill this promise. At the beginning of 2016, the company put their brand new FireLab into operation: an ultramodern fire-testing laboratory in which fire detectors of the latest generation are developed and tested using sophisticated methods. “We have eight different test fires in order to check our fire detectors for their suitability for daily use and to test various environmental conditions,” explains Urs Schmid, head of the FireLab.
A demonstration shows how this works in the everyday laboratory practice: Inside the fire room – a space of almost 100 square meters with white tiled walls that make one think of a cooling system – an alcohol fire is ignited. The flames flicker yellow and orange on the concrete floor as weak smoke rises to a ceiling mounted with various fire detectors to be tested. The room is completely sealed, the air filtered in and out. At first nothing happens – not until two minutes and 40 seconds later when a detector goes off. “We’re measuring temperature, the development of gasses and aerosols, as well as smoke particles,” explains Schmid. The corresponding trajectories of these parameters can be tracked on a monitor outside the fire room. Whether an alarm is triggered sooner or later depends on the fire detector’s configured level of sensitivity.
Around 1,000 test runs per detector
The FireLab includes a number of laboratories in which the devices are tested in even greater detail: the thermal testing channel measures the heat sensitivity of a fire detector and allows for different climatic situations to be played out in isolation.Another testing station is the optical laboratory: inside Siemens fire detectors are scattering angles. The optics laboratory analyzes how smoke particles are scattered because this scattering allows conclusions to be made about the size of the fire – and even about what’s being burned: wood, plastic, textiles, fluids or other materials. And finally, the gas testing channel serves to analyze what kinds of gasses are developed during a fire. The detectors from Siemens are so sensitive that they can distinguish various gasses by their wavelengths and different colors. A newly developed fire detector will be run through approximately 1,000 tests before it goes into production. And even there the devices are subject to rigorous and routine testing. The experts in Zug emphasize: “The knowledge is in the detector, not at the station.”
One major innovation is the Sinorix Silent Extinguishing Technology, or “Silent Nozzle” for short, which Siemens developed for data centers and server rooms. Some years ago, the fire safety industry recognized that magnetic hard disks and data storage systems are sensitive to noise: at a volume of 140 decibels or more, data can be destroyed. This meant that the highly pressurized, loud discharge of gas used to extinguish fires was also putting data at risk. With the innovative Silent Nozzle technology, this doesn’t happen: Silent Nozzle is a low-noise extinguishing system that avoids the destruction of data. Thus even sensitive datasets can survive a fire without being damaged.
MegaFoot Lab: Testing to the limit
In order to guarantee their everyday suitability, the systems are subjected to further tests. This is the only way that large, networked systems can be put into operation. And these systems are what the MegaFoot Lab – another beacon in the Siemens campus – puts to the test. Six kilometers of cables were installed in this new laboratory in order to simulate diverse building situations. The goal of the study: to check the interface points of differing systems and test the functionality of networks to their limits. Through these tests Siemens learns how networks with thousands of integrated fire detectors will respond.
The products from Zug, of course, have long since passed the test in the real world: Tettnang Castle in Germany, the Aydin University in Istanbul, the Ring Mall Shopping Center in Sofia and the Radisson Blu Plaza hotel in Ljubljana are examples of large buildings in which thousands of networked Siemens fire detectors protect people from fire. Reliable, safe – and without false alarms.
Irène Dietschi, science journalist in Switzerland.
Picture credits: Regine Giesecke, Architecture Photography GmbH, Siemens AG
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