| In any type of production facility, fire control | | | | advantages.Ease of OperationWhere once little lamps |
| encompasses a wide range of equipment or systems | | | | indicated a flow of sparks, the trouble message is |
| from building sprinklers to plant site fire departments. | | | | now displayed in clear text. Important functions and |
| A spark detection/extinguishing system must be | | | | all alarms are displayed clearly. The buttons on the |
| thought of as part of a plant's overall security and | | | | keypad light up and provide visual |
| safety network. Just as a residential alarm system | | | | information.Integrated MemoryThousands of events |
| provides protection to a homeowner, a spark | | | | are stored so that important information is not lost. |
| detection system provides preventive protection | | | | This enables analysis of alarms at any time: |
| against potential loss of human life, production | | | | |
| facilities, equipment and costly downtime.Where do | | | | When exactly did the spark stream happen? |
| Spark Streams appear?Spark streams in dust | | | | How heavy was the spark stream? |
| collection systems are a very common danger. They | | | | How long did the extinguishment action last? |
| are not easily detected and this means that they | | | | Where exactly did the spark stream appear? |
| may exist but are not known! Consequently, | | | | When was the system out of action? |
| attention is paid to a spark stream only when it is | | | | When and where did troubles appear? |
| too late, namely when there has been an explosion | | | | |
| or a fire.When working with industrial machinery, | | | | The answers to these questions can be found in the |
| sparks are created very quickly. A blunt tool, a | | | | memory of the control console and the danger spots |
| damaged bearing in the fan, an overheated motor or | | | | can be identified very quickly. The display field not |
| foreign body within the material can be the | | | | only shows the alarm itself, but also informs about |
| cause.Sparks are a constant danger in those factories | | | | the measures that have been taken. The memory |
| where combustible materials are being worked, | | | | content can be printed out at any time to an |
| exhausted, transported, filtered or dried.The damage | | | | external or internal printer.Automatic Function Checks |
| statistics provided by the insurance companies point | | | | To ensure cables are functioning correctly, they are |
| out that filters, dust collection bins, silos and even | | | | constantly checked for open and short circuit |
| complete production lines are the areas of a plant at | | | | conditions. In addition, spark sensor function tests are |
| greatest risk. Foreign bodies in the conveyed material, | | | | performed regularly and automatically. Extinguishing |
| defective parts of the production machinery, friction | | | | device function tests can be performed manually |
| processes as well as electrical sparks are all identified | | | | from the control console.The Spark DetectorThe |
| as fire generating. Here are the main danger areas | | | | most important component of a spark detection and |
| known: | | | | extinguishment system is the spark detector. To suit |
| | | | the different and often very severe applications, |
| Fiber and Particle Board Industry: The fiber and | | | | three different types of sensors are used. All three |
| particle board processing as well as the further | | | | sensor types have highly sensitive electronics which |
| processing of the panels by sawing and sanding | | | | detect even the smallest of glowing particles.Spark |
| Wood-Working Factories: Working of materials by | | | | Detector FM 1/8The FM 1/8 detector features |
| means of saws, planers, mortisers, hoggers, sanders | | | | reliable function even in very dense material flow or |
| and other wood working machines | | | | when a dust layer covers the optical element. It can |
| Chemical Industry: Pneumatic conveyors of dusts | | | | be used at material temperatures up to 149°F |
| and powders | | | | (65°C), which corresponds to a temperature |
| Foodstuff Industry: e.g. Coffee roasting, tobacco | | | | range of extraction systems for woodworking |
| processing and pneumatic conveying of powders | | | | machines like saws, planers, sanding machines, |
| | | | etc.Spark Detector FM 3/8The FM 3/8 detector is |
| Why is it so Dangerous?The spark itself is not | | | | used in applications with operating temperatures |
| dangerous. Here's why: For the creation of fires or | | | | above 149°F (65°C) as can appear in |
| explosions there must be three elements that are | | | | drying processes, for example. Spark radiation is |
| combined simultaneously: a combustible material, | | | | carried through fiber optic cables to the |
| oxygen and an ignition source. Removal of one of | | | | detector.Daylight Spark Detector DLD 1/8For the |
| the elements will prevent a fire or explosion.In | | | | most reliable detection of glowing or hot particles, no |
| today's production plants, we have to cope with all | | | | ambient light can be present at the sensor location. |
| elements that can lead to fire damage or cause an | | | | However, where an absolute dark surrounding cannot |
| explosion. Extraction systems and pneumatic | | | | be guaranteed, sensors that aren't sensitive to |
| conveyors increase the danger of fire. Once sparks | | | | daylight or ambient light are used. These sensors |
| and glowing embers are created, the pneumatic | | | | operate only in the infrared spectrum of light so they |
| extraction system conveys this danger very quickly | | | | can be installed at open transfer points or on |
| to other subsequent areas of the plant. The danger | | | | conveyor belts.Thermo Detector TM 1/8The thermo |
| is when two of the three elements necessary for | | | | sensor TM 1/8 is used for the additional inspection of |
| the creation of fires and explosions are transported, | | | | large areas, like filter and silo systems. Its task is to |
| namely: air and ignition sources (sparks).When this | | | | monitor these areas for self-ignition of the material |
| conveyed danger meets combustible materials (filter | | | | being conveyed or stored.The Extinguishing |
| cloth, deposited and combustible dust in a separator | | | | DeviceWater is the best extinguishing agent. Its |
| or silo) it becomes more and more likely that a | | | | excellent extinguishing efficiency mainly results from |
| reaction will happen.Environmental protection | | | | the high ability of heat absorption. For this reason it |
| measures regarding dust emissions and tightened | | | | has a strong cooling effect that prevents re-ignition |
| regulations for air pollution led to an increased use of | | | | of the combustible materials.To obtain an optimal |
| filter systems, but the danger of dust explosions has | | | | extinguishing efficiency, the area covered by the |
| not been reduced. In the process of drying, the | | | | water must be kept as big as possible. This is |
| dryer capacities have been steadily increased so that | | | | accomplished by a fine atomization of the water. |
| prevention of fires in these systems has become | | | | Atomization is achieved through a special nozzle and |
| more important than ever.What happens after a filter | | | | sufficient operating water pressure. With high |
| fire? Environmental regulations prohibit plant operation | | | | atomization, the amount of extinguishing water can |
| without the filter system. The plant will not only have | | | | be minimized so that filter elements are not damaged |
| the cost of repairing the damaged filter system | | | | by an excessive amount of water. This allows |
| caused by fire but also absorb the extremely high | | | | production to continue while extinguishing takes |
| loss of a production shutdown.According to individual | | | | place.The operating pressure of the extinguishing |
| reports, these production losses can exceed the | | | | device should be at least 60 PSI at a flow rate of 24 |
| damage costs many times over.The risk of fire can | | | | GPM per nozzle. If this pressure is not available, a |
| be efficiently reduced or eliminated by means of | | | | pressure-increasing unit must be used. Because |
| modern spark detection and extinguishment | | | | extinguishing nozzles are spring loaded and |
| systems.Returned air to the plant also requires spark | | | | flush-mounted, they are contamination-free and do |
| detection and extinguishment systems. Due to the | | | | not obstruct the material flow.Not all extraction ducts |
| high amount of material now collected in the dust | | | | of the plant are located inside the production building. |
| filter systems, in certain circumstances clean air is | | | | Sometimes the extinguishing devices are required to |
| allowed to be returned to the production buildings. | | | | be installed outside. Heat tape and insulating material |
| Enormous savings in heating energy are achieved in | | | | is used to protect water pipes and extinguishing |
| this way. A filter fire, however, could quickly be | | | | devices from freezing in areas exposed to frost. |
| transferred to the production area with devastating | | | | Special insulating bags are available for the |
| consequences.To protect such a system, all | | | | extinguishing devices.Alternatives to Extinguishing |
| extraction ducts as well as the conveying duct to the | | | | MeansIn some production and processing systems, |
| material storage should be equipped with spark | | | | water cannot be used as an extinguishing means |
| detection and extinguishment systems.How can you | | | | because it would have too much influence on the |
| take Preventive Measures?Protection can be | | | | subsequent process. This is particularly true for the |
| achieved by installing a modern spark detection and | | | | food industry where extremely high accuracy in |
| extinguishment system. The sensors detect sparks | | | | respect to the material's moisture must be observed. |
| and glowing embers immediately after their creation. | | | | There are also other industries where water is not |
| Upon detection and evaluation, countermeasures are | | | | allowed as an extinguishing agent. There are |
| induced immediately in order to eliminate the causes | | | | alternatives: Diversion gates, shut-off gates, fire traps |
| of a fire or an explosion.Let's compare fire | | | | and even the actuation of a C02 or other inert gas |
| extinguishment systems with spark detection and | | | | system.Diversion Gates, Shut-off Gates, Fire Traps.In |
| extinguishment systems. Fire extinguishing systems | | | | these industries, diversion gates to abort the material |
| combat fire after it has come to life, consuming | | | | flow or shut-off gates and fire traps to stop the |
| material and air thus producing smoke and damage. A | | | | material flow are used. When the spark sensor |
| spark detection and extinguishment system eliminates | | | | detects a spark, or when the preset spark threshold |
| one of the three elements (the ignition source) | | | | is exceeded, the installed device is activated from |
| before it becomes a fire. In this way there is no fire, | | | | the control console.CO2 ExtinguishmentIf parts of the |
| no smoke, and no damage.Spark detection and | | | | plant, complete machines or sensitive filter systems |
| extinguishment systems are able to detect even the | | | | are to be extinguished, a C02 system can be |
| smallest of sparks or hot particles in extraction ducts, | | | | activated by a spark detection system. For this |
| drop chutes or mechanical conveyors, and to | | | | application, spark sensors monitor the ducts leading |
| instantly trigger countermeasures. Countermeasures | | | | to these areas. Upon detection of sparks, an alarm |
| can be: activation of an extinguishing system, | | | | message is transferred to the CO2 system through |
| diverting the transport path or interrupting the | | | | voltage-free relays of the control console. The |
| production. All these measures are taken within a split | | | | corresponding parts of the system are simultaneously |
| second.Detection of the ignition source is made by | | | | shut-off by activating shut-off gates so that the |
| means of spark sensors recognizing the infrared | | | | incoming CO2 can now flood the contained |
| radiation of sparks and glowing particles. These | | | | area.Central Visualization SoftwareEvents recorded by |
| sensitive spark sensors are even capable of | | | | several consoles that are installed in different areas |
| detecting sparks through layers of dust or through | | | | of the plant are accessible through the visualization |
| the conveyed dense material flow. The sensors give | | | | software. Such an application offers many |
| alarm signals to the control console, which processes | | | | advantages: Central actuation and processing of all |
| the signals and activates the appropriate | | | | spark alarms on one monitor is possible. The central |
| countermeasures automatically. Normally an | | | | acquisition of all events provides the operator with |
| extinguishing device is triggered, which is installed | | | | meaningful and comparable data. The remote control |
| downstream from the spark detectors. This device | | | | of the individual spark extinguishing systems make it |
| releases a mist of water in the duct section where | | | | possible to react rapidly on each alarm event and |
| the sparks are transported. When no additional | | | | allows time and cost savings and shorter production |
| sparks are detected, the extinguishment spray is | | | | interruptions.Spark Detection and Extinguishing |
| automatically stopped. While the extinguishment | | | | Systems Insurance Premium RatesFire insurance |
| takes place, the production process can continue | | | | companies have acknowledged the minimized risk |
| unless otherwise desired. Due to this special operation | | | | when automatic spark detection and extinguishment |
| principle, spark detection and extinguishment systems | | | | systems are installed, and may grant discounts on |
| are classified differently than sprinkler systems, | | | | insurance premiums. Precondition for achieving |
| deluge systems, or even explosion suppression | | | | discounts on premium rates is the use of an |
| systems.The Control ConsoleThe centerpiece of a | | | | extinguishment system that is approved by a |
| spark extinguishing system is the control console.All | | | | commercial and industrial property insurance and risk |
| signals given by the spark sensors installed in | | | | management organization. Factory Mutual is one such |
| different plant areas are being accumulated and | | | | organization and the only North American organization |
| processed by a microprocessor. The extinguishing | | | | to test spark detection and extinguishment systems. |
| devices of the affected areas are activated without | | | | Factory Mutual requires stringent manufacturing |
| any delay.A practical fire protection concept also | | | | standards and technical reliability that not only applies |
| considers the demand for an almost uninterrupted | | | | to the system, but also to the planning, installation |
| production. The use of microprocessor technique | | | | and after-sales service.ConclusionSpark detection and |
| including the corresponding software results in new | | | | extinguishing systems are among the most efficient |
| possibilities to react on sparks. Integrated counters | | | | fire prevention systems, which is a result of their |
| and time recording systems allow an exact | | | | highly developed technique and reliability. The use of |
| assessment of the spark stream. A graded use of | | | | these systems for various applications is even |
| the existing countermeasures is then possible.For | | | | prescribed by Factory Mutual. All these factors lead |
| example, single sparks are only extinguished, but for | | | | to considerable investment reductions and improved |
| heavy flow of sparks or when single ignition sources | | | | safety for your plant, people and production.Author |
| are detected over a longer period, further measures | | | | Bob Barnum, Vice President of Sales for GreCon, Inc. |
| like machine shut down of the affected plant | | | | Bob has over 30 years of experience with pneumatic |
| sections have to be taken. Diversion of the material | | | | and mechanical conveying. GreCon is an ISO 9001 and |
| transport is also possible using fast-acting abort | | | | Factory Mutual Approved manufacture of spark |
| gates.The microelectronics has many other | | | | detection and extinguishment systems. |