GEAPS Great Lakes Regional Conference 2017 Explosion Protection Overview & Market Drivers April 6, 2017 1
Outline Combustible Dust Overview Explosion Protection Market Drivers Technology Options Questions 2
Combustible Dust Definition Very small particles become airborne settling on surfaces and within crevices throughout the manufacturing area Lighting, pipes, dust collectors, other equipment When disturbed, they can create dispersed clouds of combustible dust = explosion risk 3 Dusts diameters are typically less than 500 micron but surface area-to-volume is a key factor in rate of combustion, so shape influences combustion properties.
4 Classic Fire Triangle
5 Current Explosion Pentagon
Combustible Dusts Metals dust such as aluminum, magnesium, titanium, or steel Wood or wood products Coal or other carbon dust Plastic dusts or additives Organic dusts such as sugar, paper, soap, or dried blood even chicken poop 6
Quick Terms Dust Properties K st Deflagration Index for dust - The maximum rate of pressure rise during a contained deflagration of an optimum mixture [bar*m/sec] P max Maximum Pressure - maximum pressure developed in a contained deflagration of an optimum mixture [bar] 7
PRESSURE (BARA) Flame and Pressure Growth in a Vessel 10 K St [dp/dt] max P max 0 Pressure Wave 1100 ft./sec. Flamefront 80 ft./sec. Time 8
Equipment Involved in Dust Explosions Locations US (1985 1995) Number of Incidents UK (1979 1988) % Number of Incidents Germany (1965 1980) % Number of Incidents Dust Collectors 156 42 55 18 73 17 Grinders 35 9 51 17 56 13 Conveying Systems 32 9 33 11 43 10 Silos/Bunkers 27 7 19 6 86 13 Dryer/Oven 22 6 43 14 34 8 Mixers/Blenders >12 >3 7 2 20 5 Other or Unknown 84 23 95 31 114 27 Total 372 100 303 100 426 100 % 9 Source: Guidelines for Safe Handling of Powders and Bulk Solids, CCPS, AICHE
How to tell if your process dust is combustible? Is my dust Combustible? Easy way Sparks? Fire? Combustible Event? Test the dust Find out: Go No Go Minimal heat or energy to combust MIE minimal Ignition Energy millijoules MEC Minimal Explosible Concentration How much dust? Pressure signatures Explosion Severity Test Kst / Pmax Shouldn t I be GRANDFATHERED??? 10
Bartlett Grain Atchison, KS October 29, 2011 6 Fatalities & 2 Injuries (Grain Dust 9x more explosive than coal dust) 11
Imperial Sugar Port Wentworth, GA February 7, 2008-14 Fatalities & 38 Injuries 12
From 1980-2014 330+ MAJOR Combustible Dust Incidents N.A. 150+ Workers Killed 879+ Workers Injured $$ BILLIONS in Damages CSB Final Report November 2006 The Danger of Combustible Dust NYT August 2014 13
Organizations Involved U.S. Chemical Safety Board (CSB) Investigation Report / Combustible Dust Hazard Study Occupational Safety & Health Admin (OSHA) National Emphasis Program National Fire Protection Association (NFPA) Codes & Standards NFPA 652 / NFPA 61 Authorities Having Jurisdiction (AHJs) OSHA Fire Marshall City Inspectors Insurance Companies 14
NFPA Standards Guiding Safety Combustible Dust Standard Description Standards Around Combustible Dust NFPA 61 Standard for the Prevention of Fires and Dust Explosions in Agriculture & Food Processing Facilities (2017) Occupational Safety & Health Admin (OSHA) NFPA 652 Standard on Fundamentals of Combustible Dust (2016) NFPA 654National Standard Emphasis for the Program Prevention of Fire and Dust Explosions from National the Manufacturing, Fire Protection Processing, Association and Handling (NFPA) of Combustible Particulate Solids (2017) Codes & Standards NFPA 655 Standard for Prevention Sulfur NFPA 484 Standard around Combustible Metals NFPA 664 Standard around Wood Processing (2017) NFPA 68 NFPA 69 Standard on Explosion Protection by Deflagration Venting Standard on Explosion Prevention Systems 15
NFPA 652 (2016) Effective September 2015 New Hierarchy for commodity / Industry Standards Closest we ve been on national standard Process owner fully responsible Unawareness no longer acceptable DHA Protocol September 30, 2018 3 Year Mandatory (now out of date) Hazard Management NFPA 652 cross-references with NFPA 68 / NFPA 69 Stresses Isolation 16
NFPA 61 (2017) Effective June 2016 New Emphasis on Mitigation (Ch. 4.2.4) Clear Language on Responsibility (Ch. 5.1) Extensive Cross-Referencing to NFPA 652 Absence of previous incidents shall not be used as basis for determining if particulate is combustible (Ch.5.2.3) Hazard Identification added 3 options (Facility History, Published Data, or Testing Option) Performance-Based Design chapter present in all new generation NFPA Standards (Ch. 6) Modeling / testing meets AHJ s satisfaction then you can do it! New Chapter 7 - DHA 5 year deadline for existing processes (652 = 3 year) 17
Which Solution is the Customers Preference? Nothing Venting Most Requested Ducted Venting (often not possible) Building Venting (low awareness) Suppression / flameless Venting Containment Inert Gas / Oxygen Reduction 18
Explosion Venting 19 19
WHEN TO CONSIDER USING EXPLOSION VENTING 1. Flame trajectory and pressure wave can be safely released to atmosphere 2. Equipment is either outdoors 3. Or Indoors but safely ducted through outside wall One hydraulic diameter 20
Types of Explosion Vents Flat single Section Vents Single Section Construction Round or Rectangular Center or Perimeter Burst Limited Vacuum Resistance Poor Cycle Resist. (req. support) Sanitary Option 300F 2000F with insulation Storage Systems with no operating pressure fluctuations 21
Types of Explosion Vents Composite Vents Layers SS/Teflon/SS Round or Rectangular Center burst Limited Vacuum Resist. Fair to good Cycle Resist. NOT Sanitary 400F-1000F (with Ins.) High Temp Applications High Vacuum (round) 22
Types of Explosion Vents Round / Rectangular Compound Domed Vent Solid One-Piece Design Round or Rectangular Perimeter Burst Good Vacuum Resistance Full Vaccum Excellent Cycle Resistance Sanitary 300F-2000F (with Ins.) Good for all Applications 23
Other Domed Vents Often Fails Under Vacuum
Vent Mounting Frame Options Welded Design Bolted Design 10 September 24, 2015 25
Magnetic Burst Sensor MBS Sensor is designed for use in an intrinsically safe circuit and shall be used to shut down the process to end the supply of combustible material into a piece of equipment and to trigger an Isolation device 12 26
Lead Time & inventory Lead Time Stock Items Custom Items BS&B Inventory Management System (BIMS) 27 27
Flameless Vents 28
Flameless Vents BS&B Systems IQR flameless Vent (Intercept, Quench, & Retain) BS&B Systems R -IQR flameless Vent (Rectangular) 29
WHEN TO USE FLAMELESS VENTING 1. Flame trajectory is unsafe 2. Equipment is indoors 1. Vent Ducts would be too long 3. Cannot release the dust to atmosphere 4. Pressure shock of venting is unacceptable 5. Concern at negative publicity of simple venting 30
Flameless Vents Four Safety Functions of Flameless Vents Flame Arresting No flame escapes providing for safe operating environment. Reduces and/or Eliminates a secondary ignition Dust Retention Retains process dust after an event Pressure Absorption Reduces explosion pressure peak Temperature Control Absorbs flame front with negligible temperature rise. 31
Vents & flameless Vent Facts Passive Protection Relieves pressure Vent is sized according to strength of the vessel Opens prior to damaging integrity of the vessel NOT completely passive Yearly Inspection NFPA 68 Also requires isolation - NFPA 652 Can flameless Vents be Reused? Only on pneumatic activations Vent needs replacing 33
flameless Vent Efficiencies Rectangular Vents 64-85% Efficiency 135 o Venting (face) ~15sq ft Surface Area Dust Hazard Zone 7ft / Personnel 3.5ft Vertical or Horizontal Installation Maximum of 500Kst / 10.0 Pmax Round Vents 95% Vent Efficiency 360 o Venting (face) ~67sq ft Surface Area Dust Hazard Zone > 1ft / Personnel N/A Vertical or Horizontal Installation 34 Maximum of 500Kst / 10.0 Pmax
R-IQR Rectangular Flameless Vent Configuration Vent installation opening also allows periodic inspection without removal of R-IQR from service. 35
Design Benefits Both Models Extreme Level of Protection 500 Kst / Pmax 10.0 Both Models ATEX / EN Compliant R-IQR Trap Door for Inspections & Installation Burst Sensor to Trigger Isolation Device along with Shut-down Process 36
Chemical Suppression & Isolation 37
When to use Suppression? 1. The customer wants to avoid the full combustion process: - Unable to accept flame ball release - Unable to accept release of material (toxicity, cost, etc.) - Require fast clean up and restart of process without repair to the protected equipment 2. Can be the most cost effective approach: - Typically more economic than multiple flameless vents - Allows combination with Isolation in a single system 3. Flexible with respect to a wide range of shapes and volumes requiring protection: - Compact Cannon construction, low mass - Ability to install BS&B Cannons in almost any orientation 38
Suppression In Action Suppressor N 2 Suppressant Fireball Pressure Detector Fireball 30 ft/s Pressure Wave 1,100 ft/s 39
When Design Matters Suppression Cannon System Monitor Triplex Explosion Pressure Sensor Power Supply 40
Suppression Cannon Design Light Weight Low Pressure Nitrogen Tank Customer Replaceable Suppressant Canister 41
The Cannon Installation Advantage N 2 Mounting requirement within 10 degrees vertical Agent N 2 Agent Traditional Design Disadvantages: Requires Delivery Pipe Work Increases Installation cost Slows Agent Delivery Adds Blockage Potential The Cannon Advantage: Enables mounting at any angle Speeds agent delivery Eliminates need for costly pipe work 42
View of Triplex Sensor Assembly Pressure Sensors (3) Process Side Cutaway Side view Triplex Sensor Features: Three Pressure Sensors in One Housing; 2 must trip at the same time to trigger system; 2/3 voting logic Face 3 different directions; reduces chance of product impact or vibration induced unwanted activation. 43
Design Benefits Only requires 1 visit per year from BS&B Quarterly Inspections to be Handled by I-Paper Staff Saving $$$$ per quarter (x each system) Spare Parts Can be Stored ON SITE Greatly Reduced Down-Time for System Refit I-Paper Staff to Perform Refit Saving $$$$$ Control Panel Output to I-Paper Master Panel All Components (with exception of conduit) Included in Sale. 44
Next Steps Information needed to generate quotes Venting Dust Type (grain, metal, etc.) Kst Pmax Pred Drawing (or dims for volume) Explosion Protection Dust Type (grain, metal, etc.) Kst Pmax Drawing (or dims for volume) Duct Diameter (Isolation) Sensor type (for Isolation) Destination Country 45
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