Explosion Hazards

In the plot shown here, what label below should be inserted where the question mark is shown? (It is right where the spike of the graph occurs and there is a right triangle overlapping the spike in the curve)

(dP/dt)max

For most combustible dusts, a typical value for the minimum ignition energy is about:

10 mJ

A length to diameter (L/D) ratio of ___ is usually requires for deflagration-to-detonation transition (DDT).

10 to 60

In general, the faster the fundamental burning velocity, the greater the potential for the fuel to:

2 choices: transition to detonation and generate hazardous pressures

How is Pmax establised for...

20 liter

What is the name of the test typically used to characterize combustion behavior of both vapor-air mixtures and dust-air mixtures?

20 liter sphere test

The plot shown here represents: (its a plot with pressure on the y-axis and time on the x-axis that starts low with two characteristic bumbs and then has a sharp increase then decreases gradually)

20 liter sphere test of a dust-air explosion

BLEVE requires:

3 choices: a sudden loss, containment that causes, and a liquid that exists

What type of hazards do BLEVEs present?

3 choices: fragment, thermal, and blast

Factors that need to be considered to determine the distance a fragment could travel in an explosion include fragment:

3 choices: mass, trajectory, and shape

Which of these two illustrations represents grounding?

A, the one with a tube in the ground

The explosive behavior of a dust is related to particle ___.

All choices

When considering facility siting for explosion protection, what are the building hazards to deign against?

All of the above

Byproducts of a fire at a process facility can present a toxic hazard to:

All of the choices

What hazards can contribute to the damage and injury caused by explosions?

All of the choices

In what way(s) can ignition be achieved in the 20 liter sphere test?

All of the choices EXCEPT match

In Mexico City LPG terminal incident, fire impinging on the LPG tanks resulted in a series of ___, which destroyed the site.

BLEVEs

The change in momentum of a blast is known as the:

Blast impulse

What was the flammable material used in the process involved in the Flixborough incident?

Cyclohexane

T or F: Spring actuated relief valves are well-suited for deflagration venting because they respond quickly enough to effectively

F

T or F: Test data suggests that only aerosols in a confined cloud have the potential to explode.

F

T or F: The TNT equivalency method has been historically used for VCE blast modelling because of its accuracy estimating blast energy for these types of explosions.

F

T or F: The amount of ammonium nitrate stored at the West Texas Fertilizer Company had little impact on the overall destruction that occurred; instead, it was the fire that caused the widespread destruction.

F

T or F: The hazard zone for fires is typically defined as the region occupied by the fire itself.

F

T or F: The incident at the BP Texas refinery was confined to the plant; the surrounding community was not affected.

F

T or F: The negative phase of a blast wave does not contribute to the damage caused by the blast wave.

F

T or F: The six spherical storage tanks and 48 smaller horizontal cylindrical tanks all exploded instantaneously at the Mexico City LPG terminal.

F

Which incident discussed in this unit was a cornerstone event that prompted the need to address process safety issues around the world?

Flixborough

Failures in which two RBPS elements contributed to the Flixborough incident?

HIRA and MOC

Electric heaters and dryers are examples of which type of igntition source?

Hot surface

Among other sources, the source of energy for a pressure vessel burst resulting in a physical explosion can be:

I got it wrong but I know it is overfilling and phase change. It has to be another option so I would also pick combustion

In what ways can testing and computational fluid dynamics (CFD) programming codes be used?

Idk but it is not both to design and to evaluate. I think its not evaluate

A dust explosion requires a suspended cloud of combustible particulates at a concentration above the ____.

MEC

Which incident discussed in this unit resulted in the greatest loss of life?

Mexico

Where can you find guidelines on the design of electrical equipment within a classified area?

NEC

Which U.S. recommended practice provides criteria to determine ignitability hazards in chemical process areas using flammable liquids, gases, or vapors?

NFPA 497

Which U.S. guideline focuses on explosion protection for gaseous mixtures in pipe systems?

NFPA 67

Unit 2

Question below

Final exam

Questions below

Unit 1

Questions below

Unit 3

Questions below

Unit 4

Questions below

Unit 5

Questions below

When measuring blast wave pressure, if the pressure transducer is at right angles to the blast wave, the overpressure measured is called the:

Side-on overpressure

'Sublimation' refers to a phase change from:

Solid to gas

A loose connection in a meter or radio can be an ignition source for an industrial fire or explosion.

T

T or F: A cold fuel released and mixed with hot air or contacting a hot surface can autoignite.

T

T or F: Combustible aerosols are sometimes created intentionally.

T

T or F: It is generally considered impractical to eliminate all possible ignition sources in a process facility

T

T or F: NFPA 69 permits operating systems above the UFL under specific conditions.

T

T or F: Pressure vessel bursts can occur with inert gases or mixtures.

T

T or F: The explosion that occurred at the West Texas Fertilizer Company caused extensive damage and destruction in the town of West, Texas.

T

T or F: The fundamental burning velocity is the highest achievable value that is obtained in a quiescent environment.

T

T or F: The higher the explosion energy, the greater the impulse at a given peak pressure.

T

T or F: The initial change in the gas, density, pressure, and velocity of air that occurs with a blast can be either discontinuous or gradual.

T

T or F: The minimum ignition energy of a material is difficult to characterize and is highly dependent on the experimental configuration.

T

T or F: The most common RPT is due to the sudden exposure of a material to another material which is at a high enough temperature to cause the phase change.

T

The ___ method is a simple way to equate a known energy of an explosive substance to an equivalent mass of TNT

TNT equivalency

Which case discussed in this unit involved improper storage of a large quantity of explosible material near combustible material?

West Texas Fertilizer Company

Elbows, bends, and internal obstacles may increase turbulence ___ run-up distance.

and reduce

The ___ is the lowest temperature at which a fuel-oxidant mixture will spontaneously ignite under specified test conditions.

autoignition temp

Combustible liquid aerosols are liquid droplets small enough to remain suspended in air for prolonged periods of time which are released at a temperature ___ their flash point.

below

In a physical explosion, when a vessel under pressure bursts, the sudden expansion of a compressed gas generates a ___ that propagates outwards from the source.

blast wave

As pressure increases, the minimum ignition energy

decreases

As temperature increases, the minimum ignition energy:

decreases

What is the term used to describe a combustion or decomposition reaction that propagates by heat and mass transfer through the unreacted medium at a velocity less than the speed of sound?

deflagration

Passive isolation includes:

deflagration only

What is the name of the device shown below? (It looks like a sprinkler head)

end-of-line arrester

Unlike ___, which allows the static charge to drain away, ___ equalizes the potential

grounding, bonding

Why were the people and structures outside of the T2 Laboratories fence affected by the explosion

idk but its not only structures and the effects. I think it's those two and poor communication

The ignition of a flammable material may result in which type(s) of fire?

idk honestly, it is not only fireball and flash fire: it might be all of them? maybe not jet fire

The AIT of a mixture generally ____ as mixtures become either rich or lean.

increases

If a vessel containing liquid propane suddenly loses containment, the pressure will drop and ____.

liquid propane will flash to vapor

Deflagration time scales are typically measures on the order of:

milliseconds

Among other safety measures, explosives manufacturer facilities often use ___ and separation distance to prevent shock ignition of explosive material in neighboring building.

minimization

Which of the following should not be permitted to operate in areas where flammable materials might be present?

not fuel+ignition+oxidizer. I think it's just oxidizer and ignition

____ is a measure of the work done by the positive phase of the explosion at a specific location.

positive phase impulse

When a gradual change occurs in the gas density, pressure, and velocity of the air as a result of a blast, this is referred to as a _____.

pressure wave

A discontinuous change in gas density, pressure, and velocity of the air surrounding an explosion point is known as a:

shock wave

What does the term "run-up distance" refer to?

the distance between the steady deflagration

What is the general name of the device that detects and stops combustion in a confined space while the combustion is still in its beginning stage, preventing the development of pressures that could result in an explosion?

um it's not deflagration arrestor so ig it might be rotary valve

In the West Texas Fertilizer Company case, the majority of the fatalities were _____.

volunteer firefighters