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Name
Reg No

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
07 THRISSUR CLUSTER
THIRD SEMESTER M.TECH. DEGREE EXAMINATION DEC 2017
Department: Chemical Engineering
Specialisation: Process Control
07CH 7111 Process Safety Engineering
Time 3 hours Max.Marks: 60
Answer all six questions. Part of each question is compulsory.
Answer either part or part of each question
Q.no. Module 1 Marks
1a What are the hazards of Ionizing and Non ionizing radiation? Explain. 4
Answer b or c
b With help of suitable examples, discuss the condition which leads to runaway
reaction.
5
c Discuss about the most preferred approach in addressing industrial hazards
with suitable examples.
5
Q.no. Module 2 Marks
2a Create a methodology for Inventory analysis and explain its significance. 4
Answer b or c
b Flixborough incident is considered as the eye-opener of Industrial safety in the
world scenario. Justify and explain the possible reason for Flixborough
incident.
5
c Determine 8hr TWA worker exposure if the worker is exposed to toluene
vapours as follows.
Duration of exposure ppm
2 110
2 330
4 90
5
Q.no. Module 3 Marks
3a Explain the salient features of FMEA technique and write the applications. 4
Answer b or c
b Draw the Fault tree of Unconfined Vapour Cloud Explosion of leakage from
LPG tanker.
5
c A liquid storage tank is filled by pump P1. It has a level indicator LI, a level 5
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alarm LA and a trip LT at successively higher levels. The pump discharge line
to the storage tank has independent shut off valves V1 and V2, both of which
are operator actuated. LI is simply an indicator, LA has an audible alarm and
LT automatically trips the pump in case of a very high level. Draw a fault tree
for the top event Tank overflows. Estimate the probability of overflow using the
following data.
Event Description Probability
A Valve V1 stuck open 0.01
B Valve V2 stuck open 0.01
C Level indicator LI fails flow 0.01
D Level alarm LA fails 0.0005
E Pump trip fails 0.005
H Operator fails to respond to LI 0.03
K Operator fails to respond to LA 0.01
Q.no. Module 4 Marks
4a Define ALR, ELR and stability of atmosphere. Which stability criterion is more
suitable for dispersion of gases in the atmosphere? Why.
4
Answer b or c
b A gas with a molecular weight of 30 is used in a particular process. A source
model study indicates that for a particular accident outcome, 1 kg of gas will be
released instantaneously. The release will occur at ground level. The plant
fence line is 500m away from the release.
Determine the time required after the release for the centre of the puff to
reach the plant fence line. Assume a wind speed of 2m/s.
ii) Determine the Maximum concentration of the gas reached outside the fence
line. Assume stability class σy =6.1 σz =2.2 m and σy σz.
iii) Determine the distance the cloud must travel downwind to disperse the
cloud to a maximum concentration of 0.5 ppm. Assume σy or σx 0.02 x 0.89,
σz 0.05 x 0.61.
5
c Explain the salient features of dense gas dispersion model with suitable
example.
5
Q.no. Module 5 Marks
5a Discuss the role of vulnerability model in consequence analysis. Write the
probit equation for toxic effects.
5
Answer b or c
b Generate a methodology for calculation of Individual risk and how do you
represent the individual risk.
7
c
i. Determine the likely percentage of fatalities from a 500 seconds exposure of
200 ppm of Ammonia. For ammonia -35.9, b 1.85, n=2.
ii. Define MAH unit.
4
3
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Q.no. Module 6 Marks
6a Explain the concept of process reliability and write the ways to improve the
process reliability.
5
Answer b or c
b Briefly explain various techniques for assessing human error. 7
c Explain the concept of inherent safety. Describe the various tools for
assessing inherent process safety.
7