2007 Explosion Protection Solutions

Fike Explosion Protection

Seminar

Presented by

Jeff Mycroft B.Sc

Ontario Regional Sales Manager

file:///G:/Fike Explosion Presentation/opening videos.ppt#1. PowerPoint Presentation

Welcome to our growing list of seminar recipients

Ontario Fire Prevention

Officers Seminar

BC Ministry of Mines Cold Springs Farm Inc

Hexion Inc

Tiger Drylac

Geomatrix Consultants

Mallot Creek Associates Inc

Global Risk Consultants

Magellan Engineering

Consultants

Greater Toronto Airports

Authority

LCI Engineering Inc

SNC Lavalin Toronto

Iogen Corporation

Amec Engineering

Baking Association of

Canada

Hamilton Fire Services

Simcoe County Fire

Prevention Officers Assoc.

St. Marys Cement

Toronto Fire Services

SNC Lavalin Halifax

JNE Consulting Limited

Colt Engineering Toronto

Quadro Engineering

Geomatrix Consultants Inc

Industrial Accident Prevention Assoc.

DustControl Inc

ICI Explosifs

Genpharm Inc

Ontario Ministry of Labour

Neill & Gunter Limited

Sandwell Engineering

Canadian Fire Safety Association

Hite Engineering

Smith & Anderson Architects

Patheon Labs

Tate & Lyle, (Redpath Sugars)

U.S. Filter, Asdor Products

Leber Rubes

Atlantic Air Cleaning Specialists

Mississauga Fire & Emergency Services

Stone & Webster Canada

Ontario Industrial Fire Protection Assoc.

Bregman & Hamann Architects

Stantec Engineering

JNE Pharmaceutical Division

Colt Engineering Sarnia

Durham Region Mutual Aid Fire Fighters

Assoc.

Apotex Inc.

3M Perth

Fire Marshall’s College of Ontario

Nederman Canada

Office of the Fire Marshall of Ontario

Air Separation Technologies

Toronto Fire Services

O’Hara Technologies

Society of Fire Protection Engineers

Toronto Transit Commission

Mohawk College

UMA Industrial Group

Markham Fire & Emergency Services

Sheridan College

Halton Hills Fire Protection & Prevention

Services

Canadian Fire Safety

Association

Explosion Suppression

Explosion Protection Solutions

Practical Guide on:

Open air cornstarch deflagration

Explosion Venting

Explosion Isolation

Explosion

Fundamentals

Between 1980 and June 2005 there have been 197 reported Dust Explosion incidents in the United States, causing 109 fatalities and 592 injuries

US Chemical Safety Board

These numbers EXCLUDE grain and coal mining incidents

Almost 8 dust explosions / yr or

~ one every SIX WEEKS

Explosions by Industry

33%

20%

10% 8%

8%

6%

Other

Wood Processing

Food Product Mfg

Furniture Mfg

Non-Ferrous Metal

Electric Generating

Paper / Pulp Mfg

Machinery Mfg

Plastic Processing

Non-Ferrous Metal Mfg

Ore Concentration

Misc Mineral Mine

Iron/Steel Mfg

Factory Mutual Data Sheet 7-76

Explosions by Industry

24%

15%

12% 8%

8%

8%

7%

7%

7% 4%

Food Products

Wood Products

Chemical Mfg

Primary Metal Ind

Plastic/ Rubber

Electric Services

Other

Fabricated Metal

Equip Mfg

Furniture

US Chemical Safety Board Investigation Report “Combustible Dust Hazard Study” Nov 2006

Explosions by Material

US Chemical Safety Board: Investigation Report “Combustible Hazard Study” Nov 2006

24%

23%

20% 14%

8%

7%

4%

Food

Wood

Metal

Plastic

Coal

Other

Inorganic

Explosions by Equipment Type

53%

15% 7%

7%

6%

4%

4% 4%

Dust Collector

Pulverizer / Mill

Dryer/Oven

Conveyor/Elevator

Silo/Bin

Sander

Electro Precipitator

Grinder

Factory Mutual Data Sheet 7-76

U.S. Grain-Dust Explosions,

1996-2005 (SOURCE: Robert W. Schoeff, Kansas State University, and FGIS-USDA., Mar 20 2006)

Total: 106

Fewest: 6 (2004)

Most: 18 (1998)

Total Killed or Injured: 142

Total Damage: $162.8M

Highest Hazard: Corn (57 incidents)

Bucket Elevators involved in 51 incidents

12

Brief History of Major Events

5 elevator explosions in the United States in December 1977, resulting in 59 deaths and 48 injuries prompted a committee to be formed by the National

Academy of Sciences (NAS )

From 1979 to 1981, the (NAS) Panel on Causes and Prevention of Grain Elevator Explosions

investigated 14 grain elevator explosions in USA.

of the 14 primary explosions…

were followed by secondary explosions - which generally caused most of the resulting damage.

Continental Grain Co, Westwego La, Dec 22, 1977

The top 100’ of head house atop this 250’ tall grain elevator facility was blown

away, killing 36 and injuring 9, making it the worst such disaster in U.S. history.

Blaye France, Aug 20 1997

Corn Wheat & Barley stored in 72 silos, 20’ dia x 120’ tall

22 silos remained standing after event, although all were damaged.

Ignition due to fan or auto-ignition

11 people killed, 6 in offices under outflow

Blaye France, Aug 20 1997

AZF Fertilizer, Toulouse France, Sept 2001

Silo holding 300 tons of Ammonium Nitrate.

29 killed, 441 hospitalized.

3000 homes and apartments damaged or destroyed.

West Pharma, Kinston N.C., Jan 2003

Kinston N.C.

Rubber & Plastic Dust.

4 killed, 15 hospitalized, 10 critical. Damage est $150 million.

CTA Acoustics, Corbin Kentucky Feb 20 2003

Phenolic Resin Dust Kst 165

7 Killed, 37 injured

Dust lifted during cleaning operations ignited by fire in open oven

3 identified explosions destroyed manufacturing area

Most fatalities did not occur at explosion locations

World’s largest grain elevator (by capacity), including 246 circular grain silos, 30' dia x 120' tall, 3 silos abreast.

164 star-shaped interstice silos (spaces between the circular silos) also used for grain storage.

Total 310 grain storage silos.

7 killed, 10 injured

DeBruce Grain Elevator, Witchita

Kansas, June 8 2003

DeBruce Grain Elevator, Witchita

Kansas, June 8 2003

Halifax Grain, Halifax N.S. Aug 7 2003

365 Silos, most 108’ tall x 16’ dia

Some up to 32’ dia

No injuries, 400 people evacuated


16’ dia 32’ dia

Lots

more

Gallery!

New Neighborhood built 1990

Tafisa Canada, Lac-Megantic, Quebec Apr 17 2006

• Largest particleboard Manufacturing facility in the WORLD.

• Quebec’s largest industrial accident ever

• Built in 1990

• 325 employees

• Wood flour

Tafisa Canada, Lac-Megantic, Quebec Apr 17 2006

Domino Sugar Baltimore, November 2nd, 2008

Explosion at Ind. furniture plant injures 10

Fri Jan 9, 2009 5:19 pm ET JASPER, Ind. – An explosion at a southern Indiana wood laminate plant Friday sent 10 workers to a

hospital with injuries, collapsed walls and set dust on fire, authorities said. The injuries were not considered life-threatening, and all 10 workers were released after treatment, said

Rita Howell, a spokeswoman for Jasper Memorial Hospital and Health Care Center. The explosion at the Indiana Laminate plant occurred when a board became stuck inside a machine,

caused a spark and triggered the explosion, Fire Chief Kenny Hochgesang said. "We have several walls that have collapsed," Hochgesang said.

The explosion also caused a fire in a dust-collection system outside the plant, but it was extinguished in 40 minutes, Hochgesang said.

At least six of those hurt were working in the immediate area of the explosion, Hochgesang said. The plant employs about 60 people, but not all were believed to be there at the time.

The explosion occurred about 7:15 a.m. Workers built dikes to contain the water runoff to mitigate any environmental threats, Hochgesang said.

Officials of Indiana Furniture Industries, which owns the plant, did not immediately return messages. Jasper is about 50 miles northeast of Evansville.

What is an Explosion?

Industry Definitions

Explosion

“Rupture of an enclosure due to the internal pressure from a deflagration.”

Deflagration

“Propagation of a combustion zone at a velocity that is LESS than the speed of sound.”

Detonation

“Propagation of a combustion zone at a velocity that is GREATER than the speed of sound.”

Explosion Ingredients

Fuel – Dust or Gas, or Both. Dust

must be IN SUSPENSION.

Oxygen – Usually Air, but

sometimes a process ingredient,

and sometimes a product of

combustion.

Containment

The “Mystery” Ingredient….

…an Ignition Source

Top identified Explosion Ignition Sources

“Other” 21 %

Process Friction 10 %

Electricity 9.3 %

Unknown 8.7 %

Mechanical Spark 7.3 %

Cutting / Welding 6.6 %

Per FM 7-76 2006

Minimum Ignition Energy (NFPA-68 2007 assumes 10 mJ ignition)

Potential MIE Stored Energy

Single Screw .01 mJ

Flange 2” thk 0.5 mJ

Funnel 6.0 mJ

Person 15 mJ

40 Gal Drum 40 mJ

Tanker Truck 100 mJ

Zirconium Hydride 0.19 mJ

Titanium <.036 mJ

Sulphur <0.043 mJ

Al flakes <0.018 mJ

10 mJ

What kind of stuff explodes?

propane

acetylene

hydrogen

methane

alcohol

solvents

petrochemical fumes

etc...

wood

plastics

grain

pharmaceuticals

aluminum

ink toner

chocolate

etc…

Gases & vapours Dusts

Explosibility Rule of Thumb

“If it will burn as a solid,

it can deflagrate or detonate

as a dust in suspension.”

Explosion Characteristics

Flame and Pressure Waves (2 Components)

PR

ES

SU

RE

(B

AR

A)

TIME

Explosion

KSt

[dp/dt]max

Explosion Pressure Curve

10

0 Normal pressure

Pmax

Explosibility Index

KSt (bar-m/sec) = (dp/dt)maxV1/3

Kst

200

201-300

300

Hazard Class

St-1

St-2

St-3

Pmax

10

10

12

file:///G:/Fike Explosion Presentation/Kst.xls


MATERIAL Particle Size

Microns (μ)

PMAX

bar

KSt

bar-m/sec

Hazard

Class

COAL

(Bituminous) 24 9.2 129 1

SUGAR 30 8.5 138 1

POLYETHYLENE <10 8 156 1

CORNSTARCH 7 10.3 202 2

ALUMINUM 29 12.4 415 3

Explosibility Data

So the Kst of sugar is…..? Kst

102

28

99

138

165

31

ST-2

All of the above

Description Mean Particle Size

Fructose 150 μ

Fructose 200 μ

Pectin 17 μ

Refined Cane 30 μ

Beet 27 μ

Beet 250 μ

Icing Sugar 27 μ

All of the above !!

…And the Kst of Aluminum is?

NFPA-68 2007 Table F.1(d)

Aluminum, median 29 micron

diameter.

Kst 415 bar-m/sec.

Canadian Centre for Occupational Health & Safety, “Working Safely with Aluminum Powder”

Aluminum, Atomized and Flake

Maximum Rate of Pressure Rise:

Greater than 20000 psi/sec,

or 1380 bar/sec

Kst explained

Generally, max pressure generated (Pmax) will

typically be 8-10 barg (116 to 145 psig)

…and that pressure will be generated at:

Max barg per sec=

50

200

300

450

If Kst in 1m3 vessel =

50

200

300

450

Max psig per sec=

725

2900

4350

6525


So how much time do I have…?

50 50 725 0.20

200 200 2900 0.05

300 300 4350 0.033

450 450 6525 0.022

Assuming a fictional scenario involving a constant rate of pressure rise to 10 barg (145 psig) in a 1m3 vessel:

Kst bar/sec psi/sec Time

Average duration of an eye blink, is 0.250 seconds



Average duration of an eye blink, is 0.250 seconds Average duration of an eye blink, is 0.250 seconds

NFPA-68 2007 edition

Para 6.1.2

“For Dusts, Kst & Pmax values shall be determined

…per ASTM E 1226 or ISO 6184/1”

Para 8.1.2.2

When the actual material is available, the Kst shall be verified by test”

Appendix F.2:

“The user is cautioned that test data on the flammability characteristics of dusts are sample specific.”

Governing Documents

file:///G:/Fike Explosion Presentation/1999 EP Solutions.ppt#3. Explosion Protection Solutions

Current NFPA Documents

NFPA-68 2007 Standard on Explosion Protection by Deflagration Venting

NFPA-69 2008 Standard on Explosion Prevention Systems

Current NFPA Documents

NFPA-654 2006 Standard for the Prevention of Fire & Dust Explosions from the Manufacturing, Processing & Handling of Combustible Particulate Solids

NFPA-61 2008 Standard for the Prevention of Fires and Dust Explosions in the Agricultural and Food Processing Industries

NFPA-664 2007 Prevention of Fires and Explosions in Wood Processing and Woodworking Industries

Referenced Documents

CURRENT EDITION

2007 OFC TABLE 1.2.1.A

2005 NFC TABLE 1.3.1.2

NFPA-68 2007 1994 2002

NFPA-69 2008 1992 2002 1992

1994

2005 National Fire Code 5.3.1.4

Collectors > 0.5 m3 shall be located outside and equipped with Explosion Vents, or

Indoors equipped with venting ducted to outside, or

Equipped with an Explosion Prevention System.


Vents are to be applied to dust producing processes per NFPA-68 2002 edition


Where conditions exist that prevent adequate Explosion Venting, an Explosion Prevention System shall be provided,….as described in NFPA-69 (2002 edition) Explosion Prevention Systems.

2007 Ontario Fire Code

5.10.1.5. (1) Except as provided in Sentences (2) and (5), a dust collector shall be located outside of a building.

(2) A dust collector is permitted to be located inside a building if it is: (a) provided with explosion venting to the outdoors in conformance with NFPA

68, “Guide for Venting and Deflagrations”, (b) equipped with an automatic explosion prevention system or (c) located in a room (i) with fire separations having a minimum 1 h fire-resistance rating, (ii) provided with explosion venting to the outdoors, and (iii) used solely for the housing of dust-collecting equipment.

(4) Existing explosion venting to the outdoors providing not less than 0.1 m2

of vent area for each cubic meter of dust collector enclosure volume is deemed to be in compliance with Clause (2)(a).

Comparison of NFPA-68 editions

Section 1 Questions

1. What is Kst of Wood?

2. What is minimum Kst value which constitutes an “Explosion Hazard”?

BREAK !

1. Define The Hazard

2. Choose The Protection Method

Explosion Protection 2 Easy Steps

Step 1 Defining the Hazard –

Equipment at Risk

Dust Collectors

Filter Receivers

Spray Dryers

Fluid Beds

Cyclones

Silos

Vibrating Screens

Pulverizers

Pneumatic Grinders

Thermal Oxidizers

Ovens

Dryers

Conveyors

Bucket Elevators

Etc…etc…etc…

Step 2 Choose the Protection Method

Preventative Approach

Or

Responsive Approach

Preventative / Responsive

Limit Oxygen

Control Fuel Concentration

Eliminate Ignition Sources

Detect and respond to sparks

Eliminate Human Error

Containment

Flame Venting

Flameless Venting

Isolation

Suppression

RUN !!

.

Explosion Containment

Containment per NFPA-69 Explosion Prevention Systems, Chapter 10

Vessel designed to withstand max pressure generated (typ 10 -12 barg)

Vessel must be isolated to prevent flame and pressure propagation

Can be extremely expensive – vessels must be constructed in accordance with ASME VIII Pressure Vessel Code.

.

Explosion Venting

Venting Concept

A predetermined area Av releases pressure at a given level Pstat resulting in a reduced pressure Pred.

Explosion flame, pressure and unburned mixture are vented to a safe area. (the most widely used method)

PR

ES

SU

RE

TIME

Explosion

KSt

[dp/dt]max

Explosion Pressure Curve

Pmax

Normal pressure

PR

ES

SU

RE

TIME

Vented Explosion

Pmax

Pstat

Pred

Venting

Efficiency

Normal pressure

A Successful Venting

Expect a serious fire after venting

NFPA-68 2007 Chapter 8 Venting of Deflagrations of Dusts & Hybrid

Mixtures Av is the total of SEVEN separate calculations:

1. Min area

2. L/D > 2 compensation

3. Tangential flow exceeding 20 m/sec compensation

4. Vent Panel mass compensation

5. Partial volume effects

6. Initially elevated Pressure (>0.2 barg)

7. Discharge Duct compensation

Equation 8.2.2. Minimum Required Vent Area:

Av0=1x10-4(1+1.54Pstat4/3) x Kst x V0.75 x √(Pmax/Pred)-1

Equation 8.2.3 if L/D > 2 then:

Av1 = Av0 x [1+0.6 x (L/D-2)0.75 x exp (-0.95xPred2)]

Equation 8.2.6.8. If Axial or Tangential Air Velocity exceeds 20/m/sec then:

Av2=[1+(max(Vaxial,Vtan)-20/36) x0.7] x Av1

Equation 8.2.8 If Vent mass exceeds threshold mass then:

Av3 = [1+(0.0075).M0.6 x (Kst0.5/n0.3) x V x Pred

0.2] x Av2

Equation 8.3.1 If Partial Volume effects apply then:

Av4=Av3 x Xr-1/3 x √[(Xr-(Pred/Pmax))/1-(Pred/Pmax)]

Equation 8.4.1 If Initially Elevated Pressure (>0.2 barg) then:

Avep=Av1/Av0x10-4[1+1.54X(Pstat-Pinit/1+Peff)4/3]xKst.V

.75x√(1/II eff)-1

Equation 8.5.1a Effects of Vent Ducts if applicable:

Avf=Av4x(1+1.18xE10.8xE2

0.4)x√K/K0

Dust Collector Vent Location

Vents should ideally be completely below bags. Use Vol below tube sheet.

Partially below bags, with retention devices is acceptable, use dirty vol.

In the middle of the bags, with retention devices and bags removed is also acceptable – use Full Vol.

Flame discharge length (Assuming 1 vent, agricultural dust)

D=K x (V/n)1/3 1 m3 vessel = 8 m (26 ft)

2 m3 vessel = 10 m (33 ft)

5 m3 vessel = 13.68 m (45 ft)

25 m3 vessel = 23.36 m (76 ft)

Where ‘K’ = 10 for metal dusts, and 8 for chemical or

agricultural dusts, and ‘n’ = number of evenly distributed

Explosion Vents.

D is limited to 60 m max.

outdoors

Yes

Location Indoors

Discharge

Duct

Discharge Ducts

Available in many sizes and shapes

Diversity of materials & designs process (compatibility)

Low cost, long life expectancy

Must vent to a safe location (outdoors)

Explosion Vents Highest efficiency

Low unit mass < 2.5 lb./ft²

Certified burst pressures

Full predictable opening

Non-Fragmenting

Low maintenance requirements

Dusts

(Rolling Fireball)

Gases (Straight lines)

VENTING SUMMARY

ADVANTAGES Relatively inexpensive

Easy to install or replace

Low or no maintenance

Passive system

CONSIDERATIONS Releasing pressure does not put out the flame. Flame,

pressure and unburned products will exit through the vent and may cause further damage or injury.

Toxic products may be dispersed into the atmosphere.

Flame and Pressure propagation through connecting lines should be expected

A serious fire afterwards should be expected


Venting Examples


Bucket Elevators

EXAMPLES

Coal Dust Collector

Flameless Venting

Flameless Concept

Release pressure, without releasing flame.

Same venting approach as flame venting – with addition of a “muffler” or Flame Quench.

Flameless Venting


Elevex, Bucket Elevator Flameless Vents

Advantages / Considerations

No flame

Allows indoor venting

Does not address flame propagation.

Expensive

Large areas needed

Radiant heat and room pressurization

Explosion Isolation

Reminder ………

From 1979 to 1981, the (NAS) Panel on Causes and Prevention of Grain Elevator Explosions

investigated 14 grain elevator explosions in USA.

of the 14 primary explosions… 12 were followed by secondary explosions - which generally caused most of the resulting damage.

NFPA-68 2007 Annex A.8.10

“Interconnections between separate pieces of equipment present a special hazard….the effects can be significant…isolation devices should be considered… Without successful isolation or venting of the interconnection, vent areas calculated…can be inadequate. Equations 8.2 and 8.2.3 can give insufficient vent area if a dust deflagration propagates from one vessel to another…”

NFPA-69 2002 Para 9-1.1

9-1.1) The technique for deflagration isolation shall be permitted for interruption or mitigation of flame, deflagration pressures, pressure piling, and flame jet ignition between equipment interconnected by pipes or ducts.

Explosion pressure and flame will propagate through process interconnections to other plant equipment or personnel occupied areas.

Explosions in connected vessels (secondary explosions) tend to be of higher severity than explosions occurring in single unconnected vessels because of precompression and flame-jet ignition.

St-2 & 3 deflagrations can accelerate to detonation velocities while traveling through pipelines.

Is Isolation really necessary?

Fike High Speed Isolation Valve Closes in 3 milliseconds

per inch diameter

Average duration of an eye blink,

is 250 milliseconds

A 24” Valve will be

fully closed in

72 milliseconds,

or less than a 1/3

of a blink

Ventex Explosion Isolation Valves

Valve Normally Open

Valve Closed by pressure wave

Chemical Isolation

Deflagration to Detonation Pipeline Propagation

Length

Propagation

Explosions in Interconnected Enclosures

P = 7.4 bar dP/dt = 32 bar/s


V = 1.0 m3

V = 5.0 m3


P = 23.0 bar dP/dt = 1,000 bar/s

V = 1.0 m3 V = 5.0 m3

Explosions in Interconnected Enclosures

Precompression

Flame Jet



1ft. min 10 dia. max

Xmax

Xmin

Explosion Isolation

Fike

Explosion Isolation

Prevents flame and/or pressure propagation

Prevents secondary explosions

Allows vents to perform as designed

Allows containment to perform as designed

Schedule 40 piping / 150# ANSI flanges required

Active system requires maintenance

Advantages Considerations

….But what if I CAN’T apply venting cuz……

My vessel isn’t close to an outside wall

My room cannot tolerate radiant pressurization

My vessel won’t withstand the min design pressure if I duct a vent

My process is toxic or a controlled substance

Building modifications are too expensive

Flames flying out of my factory are not good for my Public Relations


INSTEAD OF Venting… INSTEAD OF

Deflagration Suppression Discharge Cloud Profile

20 Millseconds

40 Milliseconds

60 Milliseconds

Distance (Feet)

12

10

4

8

0

6

2

12

10

4

8

0

6

2

8 6 4 2 0 2 4 6 8

Injection Suppression agent released through dispersion nozzle.

Fike

Suppression Container continues to release agent. Explosion is suppressed.

Response time is measured in Milliseconds

Fike

Suppression Concept

The heat of combustion develops pressure.

Upon pressure detection, sufficient suppressant agent is dispersed into the protected volume.

Flame is quenched which prevents any further pressure increase.

Flame, pressure and unburned mixture are contained inside the vessel

Fike Patented High Rate Discharge Design

Removable Gas Cartridge

Actuator

900 psig Nitrogen and Suppressant

Zero Restriction Nozzle

Forward Acting Non-Fragmenting Rupture Disc

Incorporated Elbow and Piping

PR

ES

SU

RE

Pmax

TIME

Suppressed Explosion

Normal pressure

TSP

Pdesign

Pdetect

System

Performance

Definition of “TSP” (Total Suppressed Pressure)

1) Detector set pressure. Typically 0.5 - 1.5 psig

2) Propellant expansion

3) Products of combustion

TSP is the sum of:

Most Fike Suppression Systems

involve TSP’s of about 3.0 psig 3.0


ADVANTAGES

Process media is contained

Chemical Isolation prevents secondary explosions

Can be used inside buildings - near personnel -

Almost eliminates possibility of ensuing fire (after initial deflagration)

Can provide automatic process shutdown

CONSIDERATIONS

Active system

Requires regular maintenance

file:///G:/Fike Explosion Presentation/2006 close loop.ppt#1. Fike Explosion Protection Solutions

2007 Explosion Protection Solutions

Documents

Transcript of 2007 Explosion Protection Solutions