FLOUR BOMB!!!!!!!!!!!!!!!!!!!!!

The Ever Exciting

Sterling and Alex

PROJECT TIME

Sterling and Alex go to Whitefish High School. They have been executing their experiment during Todd Spangler’s 2011 ADVANCED

Chemistry class.

Mister Spangler has been doing flour bomb experiments since the beginning of his teaching career. It is a tried-and-true experiment in the chemistry world, designed for teachers to impress their students. For how common-place these flour bombs may seem, Alex and Sterling still find them freshly exciting…

INTRODUC TION.

The problem was that the candle for the flour bomb would never light up twice—so Alex and Sterling set out to solve the problem.

Along with getting consecutive results, we tried to see if other baking products would have an effect on the explosion.

Baking soda, corn meal, powdered sugar, white & wheat flour

BACKGROUND INFORMATION

Typically this experiment has always been done with white flour and a medium sift and candle. Every source we found on the internet provided the same steps, but we wanted to see if that was the most efficient way to procure a massive explosion.

On May 2nd, 1878, in Minnesota there was the first famous mill explosion. It resulted from copious amounts of flour dust being produced in their factory. It takes one flame, and BOOM, the entire mill was in flames and 18 workers were killed.

A similar thing happened with the Mount Mulligan Mine Disaster of 1921 in Australia; however, this resulted from coal dust.

BACKGROU ND

National Fire Protection Association (NFPA) Combustible Dust Standards include:

Oxidant Concentration Reduction Deflagration venting Deflagration pressure containment Deflagration suppression Deflagration venting through a dust retention and

flame-arresting device

These standards are derived from safety precautions against more dust explosions.

TABLE OF PARTICLE SIZES

PARTICLE SIZE (microns) μm

One inch 25,400

Saw Dust 30 - 600

Bone Dust 3 - 300

Cement Dust 3 - 100

Milled Flour, Milled Corn 1 - 100

Coal Dust 1 - 100

Sugars 0.0008 - 0.005

Oxygen 0.0005

* 1 micron = 1,000,000th of a meter, or approximately 0.00003937 inches

WHOLE VERSUS WHITE

Whole wheat has a micron size of 150, but a typical white ground flour has a smaller particle size less than 100 microns.

This affected Alex and Sterling’s experiment when trying to get consecutive lightings.white wheat

PROCEDURE…..

By alternating their controls, Alex and Sterling used many variables to try to find the best combination of strategies.

INDEPENDENT

DEPENDENT (CONTROL)

Candle Size Flour TypeSift Size

Flour Type Candle SizeSift Size

Sift Size Flour Type Candle Size

PROCEDURE STEPS

1. Melt candle onto wooden platform so stable

2. Light candle3. Place 4ft PVC pipe over lit flame4. Check by looking down to ensure

flame5. Fill chosen sift with specified flour6. Sift the flour over open top of pipe7. Continue until explosion8. Scream with excitement9. Repeat

Data…

02468

Number of Consecutive Explosions

Number of Consecu-tive Explosions

More Data

TYPE DID IT EXPLODE?

IF NOT, WHY??

White Flour Duh …

Wheat Flour For sure …

Powdered Sugar Nope Too dense, packed together instead of combusting

Baking Soda Nope Too heavy and too fine

Corn-meal Nope Too heavy, put out candle flame because of large particle size

Bone Dust? Yup It just would

o Alex and Sterling concluded that White Flour with a Large Sift worked exceptionally well, when it comes to flammable baking products

o The wide sift provided the largest surface area for the flour to expand into a larger cloud and combust

o The small particle size of White Flour allowed more to billow into a proper dust cloud formation, and therefore explode in a bigger dust cloud

THE ULTIMATE CONCLUSION

THE ULTIMATE ANSWER

Alex and Sterling also answered Mr. Spangler’s original problem: why the candle never lit twice

SOLUTION: After the explosion, the burnt flour remains on the wick. The candle will not light or maintain a strong enough flame for the second flour bomb. Between explosions, you must thoroughly scrape off excess burnt flour from the candle wick.

Yes, their project is relevant.

Alex and Sterling’s project is a mini-scale example of what happens in massive grain/lumber/flour mills.

By identifying the most dangerous combination of variables for a PVC pipe explosion, we can identify what mills need to take more precautions against these flammable products

REAL WORLD???

Alex and Sterling have used the same concept that scientists do in preventing massive grain or wood factory explosions.

Improvements Never experiment on a windy day;

could result in person lighting on fire Do not bother with 7ft PVC pipe;

person will light on fire If there is time and proper resources,

actually try lighting bone dust on fire Do project on a larger scale

See affect in giant mill

REFERENCES

"Combustible Dust in Industry: Preventing and Mitigating the Effects of Fire and Explosions." Occupational Safety and Health Administration. Web. 25 May 2011. <http://www.osha.gov/dts/shib/shib073105.html>.

"The Cornflour ‘bomb’ - Experiments." Practical Chemistry. Web. 25 May 2011. <http://www.practicalchemistry.org/experiments/the-cornflour-bomb,224,EX.html>.

"Everything You Always Wanted to Know about Flour Bomb." Relan.net. Web. 25 Mar. 2011. <http://www.relan.net/How-to/Flour_bomb.html>.

Madrigal, Alexis. "The Explosive Truth About Modern Flour Mills | Wired Science | Wired.com." Wired. 04 Mar. 2008. Web. 31 May 2011. <http://www.wired.com/wiredscience/2008/03/the-explosive-t/>.

"Particle Sizes." Engineering Tool Box. Web. May 2011. <http://www.engineeringtoolbox.com/particle-sizes-d_934.html