GEAPS Great Lakes Regional Conference 2017

Explosion Protection Overview & Market Drivers

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April 6, 2017

Outline

• Combustible Dust Overview

• Explosion Protection Market Drivers

• Technology Options

• Questions

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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

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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.

Classic Fire Triangle

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Current Explosion Pentagon

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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

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Quick Terms – Dust Properties

Kst Deflagration Index for dust - The maximum rate of pressure rise during a contained deflagration of an optimum mixture [bar*m/sec]

Pmax Maximum Pressure - maximum pressure developed in a contained deflagration of an optimum mixture [bar]

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Flame and Pressure Growth in a Vessel

PR

ES

SU

RE

(B

AR

A)

Time

10

0

Pressure Wave – 1100 ft./sec.

Flamefront – 80 ft./sec.

KSt

[dp/dt]max

Pmax

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Equipment Involved in Dust Explosions

Locations

US

(1985 – 1995)

UK

(1979 – 1988)

Germany

(1965 – 1980)

Number of

Incidents

% Number of

Incidents

% 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

Source: Guidelines for Safe Handling of Powders and Bulk Solids, CCPS, AICHE9

How to tell if your process dust is combustible?

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• 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???

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Bartlett Grain Atchison, KS October 29, 2011 6 Fatalities & 2 Injuries

(Grain Dust 9x more explosive than coal dust)

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Imperial Sugar Port Wentworth, GA February 7, 2008 - 14 Fatalities & 38 Injuries

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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

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 Companies14

NFPA Standards Guiding Safety –Combustible Dust

• Standards Around Combustible Dust

• Occupational Safety & Health Admin (OSHA) National Emphasis Program

• National Fire Protection Association (NFPA) Codes & Standards

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Standard Description

NFPA 61 Standard for the Prevention of Fires and Dust Explosions in Agriculture & Food Processing Facilities (2017)

NFPA 652 Standard on Fundamentals of Combustible Dust (2016)

NFPA 654 Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids (2017)

NFPA 655 Standard for Prevention Sulfur

NFPA 484 Standard around Combustible Metals

NFPA 664 Standard around Wood Processing (2017)

NFPA 68 Standard on Explosion Protection by Deflagration Venting

NFPA 69 Standard on Explosion Prevention Systems

NFPA 652 (2016) – Effective September 2015

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• 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

NFPA 61 (2017) – Effective June 2016

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• 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)

Which Solution is the Customers’ Preference?

• Nothing

• Venting

• Ducted Venting (often not possible)

• Building Venting (low awareness)

• Suppression / flameless Venting

• Containment

• Inert Gas / Oxygen Reduction 18

Most Requested

Explosion Venting

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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

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

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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)

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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

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Other Domed Vents Often Fails Under Vacuum

Vent Mounting Frame Options

10September 24, 2015

Welded Design Bolted Design

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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

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Lead Time & inventory

• Lead Time Stock Items

Custom Items

• BS&B Inventory Management System (BIMS)

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Flameless Vents

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Flameless Vents

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BS&B Systems IQR flameless Vent

(Intercept, Quench, & Retain)

BS&B Systems R -IQR flameless Vent

(Rectangular)

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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

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.

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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

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flameless Vent Efficiencies

• Rectangular Vents 64-85% Efficiency• 135o 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• 360o Venting (face)• ~67sq ft Surface Area• Dust Hazard Zone > 1ft / Personnel N/A• Vertical or Horizontal Installation• Maximum of 500Kst / 10.0 Pmax

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R-IQR Rectangular Flameless Vent

Configuration

• Vent installation opening also allows periodic inspection without removal of R-IQR from service.

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

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Chemical Suppression

& Isolation

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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

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Suppression In Action

PressureDetector

Fireball 30 ft/sPressure Wave 1,100 ft/s

N2 Suppressant

Suppressor

Fireball

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When Design Matters

System Monitor

Triplex Explosion Pressure Sensor

Suppression Cannon

Power Supply

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Customer ReplaceableSuppressant Canister

Suppression Cannon Design

Light Weight Low Pressure Nitrogen

Tank

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The Cannon Installation Advantage

Mounting requirementwithin 10 degrees vertical

Traditional Design Disadvantages:Requires Delivery Pipe Work• Increases Installation cost• Slows Agent Delivery• Adds Blockage Potential

N2

Agent

N2 Agent

The Cannon Advantage:• Enables mounting at any angle• Speeds agent delivery• Eliminates need for costly pipe work

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View of Triplex Sensor Assembly

Process Side

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.

CutawaySide view

Pressure Sensors (3)

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.

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Next Steps

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

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Information needed to generate quotes…

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