Digital Re-print -               January | February 2013               Controlling the explosion risks                   w...
FEATURE      Controlling the explosion risks          within hammer mills                                                 ...
Success comes with the original product. Quality always pays off. Bühler is settingstandards in the grain processing indus...
FEATUREBespoke systems                                    processes. If unprotected, the ductwork      ment and protective...
Milling Technology magazine. 	 Content from the magazine is available to view free-of-charge, both as a full              ...
Controlling the explosion risks within hammer mills
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Controlling the explosion risks within hammer mills


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Grain and feed processed within hammer mills is common fuel for dust explosions due to the nature of its handling and storage. Any time that feed such as grain, meals and flours is handled or moved, the fine organic dusts are at risk of burning and exploding.

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Controlling the explosion risks within hammer mills

  1. 1. Digital Re-print - January | February 2013 Controlling the explosion risks within hammer millsGrain & Feed Milling Technology is published six times a year by Perendale Publishers Ltd of the United Kingdom.All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies,the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis ofinformation published.©Copyright 2013 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any formor by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1466-3872
  2. 2. FEATURE Controlling the explosion risks within hammer mills by Kevin Spiess, EMEA sales manager for explosion protection, BS&B Safety Systems, United KingdomG rain and feed processed within pared to a detonation, which exceeds the or walls can be thrown into the air by a dust hammer mills is common fuel for speed of sound in air. Most grain dusts are explosion, thus providing fuel for secondary dust explosions due to the nature combustible and can cause an explosion, but explosions. Often, these secondary explo-of its handling and storage. Any time that some types are much more dangerous than sions cause more damage than the first. Infeed such as grain, meals and flours is others, especially dust associated with corn this way, a dust explosion can jump fromhandled or moved, the fine organic dusts or sugar. room to room or from silo to silo. Thisare at risk of burning and exploding. The effects of accidental fires or explo- is a common phenomenon in grain dust sions can be devastating in terms of lives explosions. For example, one of the most lost, injuries, damage to property and the dangerous areas for grain dust explosions isExplosion causes environment, and to business continuity. in the bucket elevator or conveying system A fire or explosion results from ignition linked to a silo. The grain is always in motion,of combustible material (dust, gas or vapour) Serious secondary effects so dust is constantly generated.when mixed with oxygen in the air. When Grain dust explosions can have a cascadethis takes place inside a grain silo, process or effect. Grain dust that has settled on floors Protection measuresstorage enclosure, the rapid rise in pressure An explosion risk assessment will typi-could cause a violent explosion in millisec- cally recommend that a series of protectiononds, placing personnel and property at risk. measures be implemented. These range Just a few burning embers entering a from investment in protection equipmentdust collector are enough to trigger a dust to improvements in housekeeping to elimi-explosion. Likewise, combustible material nate the build-up of deposits of combusti-conveyed into a storage silo could become ble dust which may accumulate on beamsthe nucleus of a fire. Sparks or smouldering in the factory. These may be disturbed byparticles from hammer mill operations may a primary explosion in the process equip-spread from the mill to other more vulner- ment and result in a more severe secondaryable equipment. explosion. Most materials handling, processing and Codes and standards are now very clearstorage equipment is not designed to resist SparkEx Spark Detection and in requiring isolation of vented equipment tothe pressure of an expanding flame ball Extinguishing system prevent secondary explosions, which typi-which proceeds below the speed of sound cally have much greater potential for damagein air – known as a deflagration – as com- and destruction.10 | January - february 2013 Grain &feed millinG technoloGy
  3. 3. Success comes with the original product. Quality always pays off. Bühler is settingstandards in the grain processing industry for more than 150 years. Whether yougrind wheat, corn, rye, oat, buckwheat, soy, or malt grain – our processes andequipment are finely tuned to get the most from your grain. And this kind of pro-cess quality quickly pays off. The highest flour yields and best product qualityensure fast return on investment. Visit us at the IDMA 2013Bühler AG, Grain Milling, 9240 Uzwil, Switzerland, T + 41 71 955 11 11, F + 41 71 955 66 11 in Istanbul (April 4 – 7, 2013),, Hall 10, booth no. B2Innovations for a better world.
  4. 4. FEATUREBespoke systems processes. If unprotected, the ductwork ment and protective systems intended for My organisation, BS&B Safety Systems, and piping, as well as all the connected use in potentially explosive atmospheres onhas launched a bespoke combustible dust vessels and equipment are at risk. This the European and explosion prevention system for system is used in combination with explo- By investing in explosion protection,hammer mills based on established systems sion protection equipment on each vessel, organisations can safeguard themselves eco-developed for otherindustries. The SparkExSpark Detection andExtinguishing Systemis designed to detecthot particles, sparks andglowing embers thatmight become the igni-tion source for a fireor explosion if allowedto travel on throughpneumatic ducting andconveyors towardsother material handlingequipment. bin, or dust collector and could include nomically, follow appropriate health and By preventing sparks, embers and hot chemical suppression, explosion venting or safety standards and protect workers fromparticles from reaching dust rich down- indoor venting. potential process equipment such as dustcollectors, bins and silos, both fire and explo- Regulations, codes and standardssion risks can be managed. Because of potential health problems, Using infrared detectors, the system laws exist to ensure employers in the EU More InforMatIon:detects the radiated light emitted from protect their workers from being harmed BS&B Safety Systemssparks, glowing embers and hot particles by dangerous substances in the work- Tel: +44 161 955 4202travelling past the detection point and acti- place. In the UK, under the Dangerous Email: control circuits. The greatest sensitivity Substances and Explosive Atmospheres Website: www.bsbipd.comoccurs when these sensors are employed Regulations 2002 (DSEAR), all work-in a dark area such as closed ductwork, places where substances that couldalthough optional daylight detectors are also give rise to fireavailable for use on open conveyor belts and or explosionfor applications where light is likely to be are handled orvisible. Upon detection this system provides stored must beseveral options to manage the ignition risk: fully assessed • An electrical signal generated by and protected. the sensor activates control circuits Employers typically used to operate an automatic must carry out water-extinguishing curtain. Sparks risk assessments, can be extinguished without stopping and take steps production. to ensure they • An automated shut down of the prevent or process can prevent the feed of adequately con- combustible material. trol exposure. • Alarm and control systems can be It is important activated upon the detection of hot to include in particles for other control devices such the assessment as diverter valves. foreseeable inci- The system detectors and control unit dents and main-are ATEX certified for use in a dusty work- tenance working environment. This means there are no and plan forexpensive costs for additional wiring to run measures to befrom detectors to remote mounted control taken in theseunits and plant personnel have direct access the status of the equipment. In the event ATEX is theof an alarm condition, the operator can see name com-immediately which process is at risk. A web monly given tobased monitoring system, which allows plant Directive 94/9/managers to receive system alarms and faults EC which pro-to their smart phones, as well as monitor- vides the techni-ing the systems live on the internet, is also cal requirementsavailable. to be applied In addition to this preventative sys- and the relevanttem, systems for protection are available, conformityshould an explosion occur. A chemical assessment pro-isolation system isolates an explosion and cedures beforeprevents it from affecting interconnected placing equip-Grain &feed millinG technoloGy January - february 2013 | 11
  5. 5. Milling Technology magazine. Content from the magazine is available to view free-of-charge, both as a full LINKS This digital Re-print is part of the January | February 2013 edition of Grain & Feed online magazine on our website, and as an archive of individual features on the docstoc website. Please click here to view our other publications on January - February 2013 first published in 1891 • See the full issue • Controlling the explosion risks within hammer mills • Visit the GFMT website • • Contact the GFMT Team Recycling surplus factory food In this issue: into quality animal feeds • Efficient barge unloading technology • Use of computer • Feed • Subscribe to GFMT programming enzymes in animal diet in animal formulation nutrition INCORPORATING PORTS, DISTRIBUTION AND FORMULATION A subscription magazine for the global flour & feed milling industries - first published in 1891 To purchase a paper copy of the magazine, or to subscribe to the paper edi- tion please contact our Circulation and Subscriptions Manager on the link adove. INFORMATION FOR ADVERTISERS - CLICK HERE Article reprints All Grain & Feed Milling Tecchnology feature articles can be re-printed as a 4 or 8 page booklets (these have been used as point of sale materials, promotional materials for shows and exhibitions etc). If you are interested in getting this article re-printed please contact the GFMT team for more informa- tion on - Tel: +44 1242 267707 - Email: or visit