Code No: 07A80802 R07 Set No.

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IV B.Tech II Semester Examinations,APRIL 2011
INDUSTRIAL SAFETY AND HAZARD MANAGEMENT
Chemical Engineering
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks

1. (a) Explain in detail about vapor cloud explosions (VCE)
(b) Explain in detail about blast damage due to over pressure. [8+8]
2. What are the ways by which res and explosions prevented and controlled in pro-
cessing ammable materials? [16]
3. (a) What is the methodology used in the design of pressure relief systems?
(b) State the sequential steps involved in sizing relief systems. [8+8]
4. (a) What is the signicance of Limiting Oxygen Concentration (LOC) and how it
will be useful in determining inert gas requirements?
(b) What are the safe levels below LOC to which inerting is normally carried out?
[10+6]
5. A reactor contains the equivalent of 8000 lb of TNT. If it explodes, estimate the
injury to people and the damage structures 450 ft away.
Take deaths due to lung hemorrhage as:
y = -77.1 + 6.91 ln p
Probit equation For eardrum rupture is
y = -15.6 + 1.93 ln p [16]
Probit Percent
2.5 1
3 2.5
3.5 6.5
4 16
6. (a) What are hazard and operability studies?
(b) What are check lists? How are they useful in identifying hazards? [8+8]
7. The lid of a drum with 3ft diameter is kept open. The drum contains 42 gallons
of toluene. Determine the time required to evaporate all the toluene in the drum.
The temperature is 77
0
F. Estimate the concentration of toluene (in ppm) near the
drum if the local ventilation rate is 1000 ft
3
/min. [16]
P
sat
toluene
= 28.2 mm Hg
8. (a) Propylene is in contact with water at 87.8
0
C and 1atm in an industrial process.
The concentration of propylene in the air at the surface of water is measured at
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Code No: 07A80802 R07 Set No. 2
9000 ppm on a mole basis (y =9000 ppm (mole)). Estimate the concentration
of propylene in liquid at the surface of water.
For propylene: A = -2570.0227 ; B = 6.86740 10
4
; C = 1.03384 10
3
D = -7.1969 10
1
; T = 360.8
0
C
Take log H = A + B/T + C log
10
(T) + DT Where H = Henrys law constant
at one atm. Pressure (atm/mole fraction) A,B,C,D are constants for the gas
T = Temperature,
0
K
The partition coecient is given by K = H / P
t
where P
t
= total pressure,
atm vapour concentrations & liquid concentration. are related by y = Kx
(b) A chemical process plant has 800 workers on roll. Average number of hours of
operation of each worker is 2000. Every year, during operation, four operators
suer disabling injuries; estimate the frequency rate of injuries. [10+6]

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Code No: 07A80802 R07 Set No. 4
IV B.Tech II Semester Examinations,APRIL 2011
INDUSTRIAL SAFETY AND HAZARD MANAGEMENT
Chemical Engineering
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks

1. (a) What are the advantages and disadvantages of vacuum and pressure purging
systems for inerting?
(b) State why vacuum purging is not suitable for large storage tanks? [10+6]
2. How does a spring-operated relief valve function? Describe. [16]
3. (a) What are the scenarios that can give rise to overpressures inside pressure
vessels?
(b) Describe dierent situations for such overpressures to develop. [8+8]
4. The TLV-TWA for a substance is 150 ppm. A worker begins a work shift at 8
AM and completes the shift at 5 PM. A one hour lunch break is included between
12 Noon and 1 pm; where it can be assumed that no exposure to the chemical
occurs. The data were taken in the work area at the times indicated. Has the
worker exceeded the TLV specication? [16]
TIME CONCENTRATION
8.10 am 110
9.05 am 130
10.07am 143
11.20 am 162
12.12 pm 142
1.17 pm 157
2.03 pm 159
3.13 pm 165
4.01 pm 153
5.00 pm 130
5. Discuss and explain plant layout issues that are to be included in a hazard survey.
[16]
6. The peak over pressure expected due to explosion of a tank in a plant facility is
approximated by the equation
log p = 4.2 - 1.8 log r
Where p is the over pressure in psi and r is the distance from the blast in feet. The
plant employs 500 people who work in an area from 10 to 500 feet from the potential
blast site. Estimate the number of fatalities expected due to lung hemorrhage and
the number of eardrums ruptured as a result of this blast
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Code No: 07A80802 R07 Set No. 4
Data:
Probit equation:
for deaths due to lung hemorrhage: y = -77.1 + 6.91 ln p
for eardrum ruptures : y = -15.6 + 1.93 ln p [16]
Probit Percent
2.5 1
3.0 2.5
3.5 6.5
4.0 16.0
7. (a) List out the various rst degree and second degree hazards.
(b) Assuming that a car travels at an average speed of 50 miles per hour, how
many miles must be driven before a fatality is expected? [10+6]
8. (a) Explain the terms:
i. Auto ignition
ii. Auto oxidation
iii. Adiabatic compression.
(b) Determine the MOC of a mixture of 2% hexane, 5% propane and 2% methane
by volume. LFL for Hexane: 1.1 % by volume
LFL for Propane: 2.1 % by volume
LFL for Methane: 5 % by volume [6+10]

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Code No: 07A80802 R07 Set No. 1
IV B.Tech II Semester Examinations,APRIL 2011
INDUSTRIAL SAFETY AND HAZARD MANAGEMENT
Chemical Engineering
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks

1. Discuss about:
(a) How toxicants are eliminated from biological organisms?
(b) Eects of toxicants on biological organisms. [16]
2. What are the preventive and protective measures for a safety program in a process
plant? Describe and discuss. [16]
3. List out and explain various chemical plant control techniques to reduce the work
place exposures. [16]
4. What is an explosion suppression system? Under what circumstances it is used in
place of pressure relieving devices? [16]
5. (a) What are the three components of a re triangle that must be satised for
ignitions to occur?
(b) State the criteria for prevention of ignition of ammables? [6+10]
6. (a) Explain in detail about detonation & deagration.
(b) Explain the experimental explosion apparatus for vapors & dusts with neat
diagrams. [6+10]
7. Describe a safety review process for using a cylinder of phosgene to charge gaseous
phosgene to a reactor. Review up to the reactor only. [16]
8. (a) In a process plant, Benzene was owing through a pipeline of 50mm diameter.
The drain valve of the pipeline remained open by fault. Pressure at the up-
stream side was 13 10
5
N/m
2
while Pressure on down stream side was 1
10
5
N / m
2
. Temperature was 20
0
C. Benzene spread in the area and ignited
after 30s. Calculate the quantity of Benzene leaked through the drain valve.
Discharge coecient = 0.63. Density of Benzene = 780 Kg/m
3
.
(b) A process plant has 1800 workers on roll. Average number of hours of operation
of each worker is 2000. Number of days lost in a year due to accidents is 45.
Estimate the severity rate of accident. [10+6]

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Code No: 07A80802 R07 Set No. 3
IV B.Tech II Semester Examinations,APRIL 2011
INDUSTRIAL SAFETY AND HAZARD MANAGEMENT
Chemical Engineering
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks

1. What is the signicance and importance of Limiting Oxygen Concentration (LOC)?
What are its other names? [16]
2. How is wetted surface useful in the estimation of vaporization rates on re exposure?
[16]
3. (a) By making a mass balance on volatile vapor in an enclaser, derive an expression
for average concentration in ppm of any volatile species in an enclosure.
(b) Discuss about vaporization rate of a liquid. [8+8]
4. What are the dierent types of hazards associated with chemical process plants?
Give brief description of each of such hazards. [16]
5. (a) Discuss about safely problems in site selection & plant layout.
(b) If thrice as many people used motor cycles for the same average amount of
time each, what will happen to:
i. OSHA incidence rate
ii. FAR
iii. The fatality rate and
iv. The total number of fatalities. [10+6]
6. What are the dierences among safety valve, relief valve and safety relief valve?
Explain. [16]
7. (a) Discuss about damage produced by over pressure.
(b) Estimate the LFL and UFL of the gas mixture, composed of 1.0% ethy-
lene,1.0% Acetone, 1.0% Ethyl ether: [6+10]
LFL, vol% UFL, vol%
Ethylene 2.7 36.0
Acetone 2.5 13.0
Ethyl ether 1.9 36.0
8. A blast produces a peak over pressure of 47000 N/m
2
. What fraction of structures
will be damaged by exposure to this over pressure? What fraction of people exposed
will die due to lung hemorrhage? What fraction will have eardrums ruptured:
Probit equations:
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Code No: 07A80802 R07 Set No. 3
for eardrum rupture : y = -15.6 + 1.93 ln p
deaths due to lung hemorrhage: y = -77.1 + 6.91 ln p
structural damage: -23.8 + 2.92 ln p [16]
Probit percent
2.5 1
3.0 2.5
3.5 6.5
4.0 16

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