Dust Explosion in Malaysia : A Review

22/10/2015 Dust Explosion in Malaysia : A Review Badhrulhisham Abdul Aziz, Siti Ilyani Rani & Jolius Gimbun UNIVERSITI MALAYSIA PAHANG CONTENT OF PRESENTATION Introduction to Dust Explosion Dust Explosion Review : USA & Malaysia Causes of Dust Explosion Prevention and Mitigation of Dust Explosion Dust Explosion R&D Work at UMP 2 1 22/10/2015 S.I. Rani, J. Gimbun, B.A. Aziz Physical explosion Compressed gas/ vapour explosion (CG/VE) 3 Chemical explosion Boiling liquid expanding vapour explosion (BLEVE) Deflagration/detonation Homogeneous chemical explosion Rapid phase transition explosion Explosion which can occur in unconfined, but more likely in (partially) confined space Vapour cloud explosion Aerosol or mist explosion Gas explosion Explosion which can occur only under substantial confinement Dust explosion Fig.2.1. Scheme of explosions in chemical process industries (Abbasi et al., 2010). Exothermal explosion Condensed phase explosion Radical explosion Runaway reaction and explosion 4 2 22/10/2015 DEFINITION OF DUST Dust are fine solid airborne particles which capable to passing a standard sieve. The National Fire Protection Association (NFPA) defines dust as any finely divided solid, 420 μm or less in diameter that passed through a U.S. No 40 standard sieve (Amyotte and Eckhoff, 2010). According to British Standard Institute code BS2955:1958, dust are particles less than 76 μm in diameter (Abbasi and Abbasi, 2007). 5 Charateristics of Dust Explosion [www.dustexplosion.info] When a mass of solid flammable material is heated it burns away slowly owing to the limited surface area exposed to the oxygen of the air. The energy produced is liberated gradually and harmlessly because it is dissipated as quickly as it is released. The result is quite different if the same mass of material is ground to a fine powder and intimately mixed with air in the form of a dust cloud. In these conditions the surface area exposed to the air is very great and if ignition now occurs the whole of the material will burn with great rapidity; the energy, which in the case of the mass was liberated gradually and harmlessly, is now released suddenly with the evolution of large quantities of heat and, as a rule, gaseous reaction products 6 S.I. Rani, J. Gimbun, B.A. Aziz 3 22/10/2015 Dust Explosions Ignition Source Confinement Dispersion Deflagration Explosion FIRE Combustible Dust Oxygen in Air Require 5 Elements Simultaneously 7 Dust Explosions Factors • The dust must be combustible and fine enough to be airborne. • The dust cloud must beat the Minimum Explosive Concentration (MEC) for that particular dust. • There must be sufficient oxygen in the atmosphere to support and sustain combustion. • There must be a source of ignition. Dust Particle • The dust must be confined. • The dust must be dry. 8 4 22/10/2015 PROCESSES INVOLVED 1. The milling industries where these materials are converted into powders, flours, meals or dusts; 2. The industries that use such powders, flours, meals or dusts; 3. The industries in which metal castings, or articles of wood, cork, plastics, or other materials are smoothed or polished on abrasive wheels, polishing mops or bands, the dust being produced as an unwanted by-product. www.dustexplosion.info 9 The potential industries with dust explosions hazard (Abbasi and Abbasi, 2007; Amyotte and Eckhoff, 2010) 1) Wood processing and storage including paper products; 2) Grain and foodstuffs material and equipments such as grain dust, flour and feed mills, elevator, bins and silos; metal manufacturing, fabrication and storage of metals powders and dusts; 3) Power generation which deals with pulverized coal, wood and peat; 4) Chemical production and process industries such as pesticides, dyes and paints; plastic or polymer production and processing; 5) Food production, processing and storage including sweetener products, starch, candies and spices; 6) Rubber processing and production; 7) Textile manufacturing and processing such as wool, linen flax and cotton; and 10 8) Pharmaceutical processing plants. 5 22/10/2015 The Frequency of Dust Examples of materials that have historically caused dust explosions include: Cosmetics Coal Dyes Grain and other dry foods Metal Pharmaceuticals Plastic and rubber Printer toner Soaps Textiles, Wood and Paper 11 Typical Materials involved in incidents in USA 1980-2005 [CSB 2006] 12 6 22/10/2015 Equipment involved in dust explosions. [Zalosh et al. 2005] ( * ( + " # ! " ! # #* ! ! $ %& $' ( ) 13 Dust explosion in a work area Dust Dust settles on flat surfaces Some event disturbs the settled dust into a cloud Adapted from CSB Dust cloud is ignited and explodes 14 7 22/10/2015 The “Typical” Explosion Event Primary deflagration inside process equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 15 The “Typical” Explosion Event Shock wave caused by primary deflagration 0 25 50 75 100 125 150 175 200 225 250 300 325 16 8 22/10/2015 The “Typical” Explosion Event Shock waves reflected by surfaces within the building cause accumulated dust to go into suspension 0 25 50 75 100 125 150 175 200 225 250 300 325 17 The “Typical” Explosion Event Dust clouds thrown in the air by the shock waves 0 25 50 75 100 125 150 175 200 225 250 300 325 18 9 22/10/2015 The “Typical” Explosion Event Primary deflagration breaks out of the equipment enclosure - creating a source of ignition 0 25 50 75 100 125 150 175 200 225 250 300 325 19 The “Typical” Explosion Event Secondary deflagration ignited 0 25 50 75 100 125 150 175 200 225 250 300 325 20 10 22/10/2015 The “Typical” Explosion Event Secondary Deflagration is propagated through the dust clouds 0 25 50 75 100 125 150 175 200 225 250 300 325 21 The “Typical” Explosion Event 0 25 50 75 100 125 150 175 200 225 250 300 325 22 11 22/10/2015 The “Typical” Explosion Event Collapsed building with remaining fires 0 25 50 75 100 125 150 175 200 225 250 300 325 23 Overview - USA In US, dust explosion is a major industrial hazard. According to CSB, over the last 30 years there have been approximately 3,500 combustible dust explosions, 281 of these have been major incidents resulting in the deaths of 119 workers and another 718 workers sustained injuries. 24 12 22/10/2015 US Ink facility, East Rutherford , NJ September 10, 2012 Explosion and fire 7 injured 25 Hoeganaes facility in Gallatin, TN January 31, 2011; March 29, 2011; May 27, 2011 Metal Dust Flash Fires and Hydrogen Explosion 5 Killed, 3 Injured 26 13 22/10/2015 New Cumberland A.L. Solutions titanium plant in West Virginia December 9, 2010 Fueled by titanium powder 3 Killed 27 Imperial Sugar Company, Port Wentworth GA. Feb. 7, 2008 Explosion and Fire 13 Dead and Numerous serious injuries 28 14 22/10/2015 West Pharmaceutical Services plant in Kinston, North Carolina. January 29, 2003 Fueled by fine plastic powder 6 deaths, dozens of injuries, and hundreds of job losses 29 CTA Acoustics manufacturing plant in Corbin, Kentucky. February 20, 2003 Fueled by resin dust 7 killed, 37 injured 30 15 22/10/2015 Hayes Lemmerz manufacturing plant in Huntington, Indiana October 29, 2003 Fueled by accumulated aluminum dust, a flammable byproduct of the wheel production process. 1 killed, 6 injured 31 Overview - MALAYSIA According to DOSH Malaysia, from March 2008 to August 2013, there have been 5 combustible dust explosion incidents resulting 7 fatalities and 12 injuries. However, only 3 incidents were published in the website. 32 16 22/10/2015 Incidents in Malaysia Grain storage and milling plant, Lumut, Perak March 17, 2008 Grain dust explosion 4 Dead, 2 injured 33 Incidents in Malaysia Motorcycle rim manufacturing factory, Pulau Pinang March, 2010 Aluminum dust explosion 8 injured and cause damaged the building, manufacturing plant, dust collector system and broke the windows of nearby factories. 34 17 22/10/2015 Incidents in Malaysia Medicine and cosmetic processing plant (Exact place was not stated) Stearate based chemical explosion 2013 (Exact date was not stated) 2 dead and 2 severely injured. 35 NFPA USA STANDARD * * , ' 0" , * 1 * 2* " * * 1*/ * ! 6 #4 * * # 4 % * * ! 4 " * , * * ' , : 0 #4 , 4 . , 2 * , # 6 * #4 ! 5* * * ! 6 % . # - .&'* , * 0 * ! $ , ## 9 , *" * #4 , * 3 , * * * .&/ " -* * ## * * - .&/ * . 3 , - * * * * , 5* * * 7 * ' # ,, * , 8 " ,, * * * , * # ' #4 * * * * ; , ' %* 4 , ,* * .&/ "6 * 5* * , , * "6 , , ' - , " * ; ) < 04 * * .&/ .&/ " -* ) 36 18 22/10/2015 DUST EXPLOSION EUROPEAN STANDARD EN 14797:2006 Explosion venting devices EN 14373:2005 Explosion suppression systems EN 14491:2006 Dust explosion venting protective systems EN 15089:2009 Explosion isolation systems EN 1127-1:2007 Explosive atmospheres, basic concepts and methodology 37 Causal Factors for Dust Explosions • • • • • • Lack of hazard awareness Inadequate hazard evaluation Failure to comply with standards Poor housekeeping Inadequate change management Failure to investigate and respond to previous incidents 38 19 22/10/2015 Awareness of the Hazard • MSDSs do not convey the explosion hazard • Employees not trained about dust explosion prevention • Third-party inspections with no recognition of the hazard 39 Hazard Evaluation • Often, no hazard analysis performed • Focus on exposure hazards but not facility process safety issues 40 20 22/10/2015 Housekeeping • The worst damage from a dust explosion is often the result of one or more secondary explosions. 41 Change Management • Major modifications performed without adequate design review, hazard analysis or documentation 42 21 22/10/2015 Incident Investigation • Precursor events – Small deflagrations or fires – Events at other facilities – “Whew” events (if not for the safety device, this could have been bad) • • • • Not reported Not investigated No corrective actions taken Findings not communicated to employees 43 MEANS OF PREVENTING & MITIGATING • PREVENTION - Preventing ignition sources – Smouldering combustion in dust, dust fire – Other type of open flames – hot work – Hot surfaces (electrically, thermically or mechanically heated) – Heat from mechanical impact (metal sparks or hot spots) – Electric sparks and arcs. Electrostatic discharges 44 R.K. Eckhoff 2005 22 22/10/2015 MEANS OF PREVENTING & MITIGATING • PREVENTION – preventing explosive dust clouds – Inerting of dust clouds by N2, CO2 and rare gases – Intrinsic inerting of dust clouds by combustion gases – Inerting dust clouds by adding inert dust – Keeping dust concentration outside explosive range R.K. Eckhoff 2005 45 MEANS OF PREVENTING & MITIGATING • MITIGATION – Explosion–pressure resistant construction – Explosion isolation (sectioning) – Explosion venting – Automatic explosion suppression – Partial inerting dust cloud by inert gas – Good housekeeping (dust removal/cleaning) R.K. Eckhoff 2005 46 23 22/10/2015 Logic diagram for dust explosion hazard identification and risk reduction [Abuswer 2012] 47 Keys to Prevention • Inherently safe process design • Process itself be designed in such a way that no explosion hazard exists • Increased hazard awareness – Improved MSDSs – Dust explosions taught in undergrad curriculum – Access to NFPA standards • Applied principles of PSM – Change management; Hazard evaluation; Incident investigation; Hazard communication etc. 48 24 22/10/2015 R&D : SIMULATION OF DUST EXPLOSION FACULTY OF CHEMICAL & NATURAL RESOURCES ENGINEERING [FKKSA] 49 WHY MODELING & SIMULATION? 1. CAPABILITY OF COMPUTING POWER 2. AVAILABILITY OF RELATED SOFTWARE 3. SAFE AND RELIABLE 4. COST-SAVING AND REPEATIBILITY 50 25 22/10/2015 In UMP, we simulate the likelihood for dust explosion in silo using CFD code, FLUENT Feeding Process Explosive atmosphere Dispersion Turbulence Fuel Ignition source Factors for Dust Explosion Confinement Oxidant Mixing Dust/particles + O2 (from air) → mixture (dispersion in confined space (silo) Identify Hazards Dust cloud formation without ignition factor Understand Hazards Likelihood of dust explosion (compare to LEL value) 26 22/10/2015 Experiment vs CFD Simulation • Expensive setup & instruments • High risk • Time consuming to setup the silo • • • • Save cost No risk Provide good prediction Provide insight view Geometry and condition νin gas (air) νin solid (particles) ṁin solid (particles) 0.075m 5m 3.75m 1.6 m Feeding rate = 3 kg/m3 Conveying velocity = 23 m/s Particle mean diameter = 15:m Validated using LDA measurement by Hauert and Vogl (1995) 27 22/10/2015 Modeling Strategy CFD code, Fluent, 3D, 100% quality hexahedral grid SIMPLE scheme; 1st & 2nd order discretization; standard & PRESTO Dust cloud formation in silo Gas phase: Classical k>epsilon turbulence model Disperse phase: DPM –Eulerian Langrangian; gravity; Saffman’s force & 2 way coupling Results - Prediction of mean velocity at various levels Center of the silo = = > ## = > ## = > ## = > ## = > ## = ! 28 22/10/2015 Results - Prediction of turbulence flow at various levels % ## > ## > ## > ## " # > $ Center of the silo > ## ! Conclusion The most important factor to prevent dust explosion is by increasing the awareness of Malaysian industries that produce, process, store or use combustible dust. Malaysian industries should learn the lessons from the previous incidents occurred around the world. Simulation is one of the important and significant tools in understanding and managing dust explosion phenomena. 58 29 22/10/2015 REFERENCES 1) 2) 3) 4) 5) 6) 7) 8) 9) Abbasi, T. and Abbasi, S.A., 2007. Dust Explosions – Cases, causes, consequences, and control. Journal of Hazardous Materials 140, 7-44. Amyotte, P. R., & Eckhoff, R. K., 2010. Dust explosion causation, prevention and mitigation: An overview. Journal of Chemical Health & Safety, January/February. CSB., 2006. Investigation report: Combustible dust hazard study. U.S. Chemical Safety and Hazard Investigation Board. DOSH, 2011a. Combustible dust explosion. http://www.dosh.gov.my/ safety alert-2009 (Accessed on April 28, 2011). DOSH, 2011b. Fire and explosion at biotechnology factory. http://www.dosh.gov.my/safety alert-2009 (Accessed on April 28, 2011). DOSH, 2011c. Combustible dust at motorcycle rim manufactured factory. http://www.dosh. gov. my/ safety alert 2010 (Accessed on April 28, 2011). Eckhoff, R.K., 2009. Dust Explosion Prevention and mitigation, Status and Developments in Basic Knowledge and in Practical Application, International Journal of Chemical Engineering. Zalosh, R.G., 2003. Industrial fire protection engineering. John Wiley & Sons S.I. Rani, J. Gimbun and B.A Aziz (2014) “CFD Simulation of Dust Cloud Formation in Silo”, Australian Journal of Basic and Applied Sciences, 8(4) Special 2014, Pages: 521527. 59 30