- Open Access
- Total Downloads : 677
- Authors : Archa Tiwari, R . M. Choukse
- Paper ID : IJERTV4IS040205
- Volume & Issue : Volume 04, Issue 04 (April 2015)
- DOI : http://dx.doi.org/10.17577/IJERTV4IS040205
- Published (First Online): 04-04-2015
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Fire & Explosion Prevention Strategy in Refineries
M.Tech (Industrial Safety Engineering) Deptt. of Fire Technology and Safety Engg IES-IPS Academy, Indore,( M.P.), India
R. M. Choukse
Deptt. of Fire Technology and Safety Engg IES-IPS Academy, Indore,( M.P.), India
Abstract In current civilizations hydrocarbon are a primary source. Oil refineries are one way hydrocarbons are processed for use crude oil is processed in several stages to form desired hydrocarbons used as fuel & in other products. Hydrocarbon is useful as well as harmful if it is not treated properly and become the cause of fire & explosion. The main objectives of the paper to give a systematic approach to reduce the fire & explosion hazard in refinery. The prevention measures are to avoid any fire or explosion risks by eliminating either the potential ignition sources or both. Job Safety Analysis is the method we are applying for the fire prevention in refineries. In this we find Likelihood of occurrence, potential severity of harm by which we identify the level of risk and the prevention take place. This strategy will save the refinerys material as well as its property and mainly safe the lives of peoples.
KeywordsFire & Explosion; LPG bullet; BLEVE; Classification of petroleum products; Job safety analysis; Thermal Radiation etc.
Fire is a process in which substances combine chemically with oxygen from the air & typically give out bright light, heat & smoke. Explosion is a sudden release of mechanical, chemical, or nuclear energy is a sudden & often violent manner with the generation of high temperature & usually with the release of gases. Refinery is a production facility composed of a group of chemical engineering unit processes & unit operations refining certain materials or converting raw materials into products of value. Refinery is the highly risk prone area where the workplace hazard is occurred due to a minor mistake or irregularity and this mistake easily take a form of fire and explosion which cause a dangerous hazard. Fire & Explosion is a hazard if it occurs once then it cannot stop easily as it spread within a short period of time with the help of medium, so for the prevention of these hazard we are applying job safety analysis by which we can easily identify the risk and once risk is identify then it easy to prevent the hazard.
Some norms & laws which are applicable to petroleum industry like:
The Factories Act, 1948 with The Madhya Pradesh
/Chhattisgarh factories Rules, 1962, schedule viii Rule 107 prescribed under section 87.
The Gas Cylinders Rules, 2004 chapter II General Provisions.
The Gas Cylinders Rules, 2004 with the Static and Mobile Pressure Vessels (Unfired) Rules, 1981.
The Petroleum Act 1934, Rules 1976
The Explosive Act 1884, Rules 2008
MSHIC Rules 1989
CIMAH Regulations 1996
The motors transport workers Act 1961
The Manufacture storage and import of hazardous chemical Rules 2000
Classification of petroleum products on basis of flash points-
Class 0 Liquefied petroleum gases.
Class 1 Liquids which has flash points below 21Â°c. Class 2 Liquids flash point from 21Â°c up to 55Â°c. Class 3 Liquids flash point above 55Â°c up to 100Â°c.
Unclassified Liquids which have flash points above 100Â°c.
II. PROPOSED METHODOLOGY
Job safety analysis (JSA)
Job safety analysis is one of the risk assessment tools used to identify & control workplace hazards. A job safety
analysis is a second ties risk assessment with the aim of preventing personal injury to a person, or their colleagues & any other person passing or working adjacent, above or below. A workplace hazard is defined as anything that has the potential to injure or harm. Risk is the correlation between likelihood and consequence. Job safety analysis is an accident prevention technique that is used to find the potential hazard associated to the job and give the control measures to minimize the hazards. A job safety analysis can do much toward reducing accidents & incidents in the workplace but it is only effective if it is reviewed & updated periodically, even if no changes have been made in a job hazard that were missed in an earlier analysis could be detected. If an illness or injury occurs on a specific job, the job safety analysis should be reviewed immediately to determine whether changes are needed in the job procedure if a close call or a near miss has resulted from an employee equal to failure to follow job procedure, this should be discussed with all employees performing the job.
Job related fatal event, injuries and fatalities creates daily at the workplace. These occurring of unwanted event on the improper job procedure and on the untrained people. According to the job safety analysis method have reduced some improper job procedure and control the hazard activity of workplace. According to the job safety analysis method have some important facts and recording and selection of the job then identifying the potential hazard process and so on. JSA methodology using for the improve productivity and JSA have 4 basic step wise work which are-
Selection of jobs to be analyzing
Breaking the job down into steps
Identification of potential hazards in process
Determine preventive measure and control to overcome this problems.
The basic purpose of JSA is to identify workplace hazards with a likelihood of possible or greater, identifying problems and break the job, and then also control the main issues. The outcome of an event expressed in consequences of qualititatively or quantitatively a loss injury, disadvantage or gain.
Block diagram of LPG overfilling
Discharge of LP gas
Fire Failure to close container valve
Loss of property Fatalities or material
Jet fire LP gas
Blown out from nearby container
Sharp pressure Pressure rise rise over time
Elastic collapse by Bursting by
excessive pressure external force
Rupture Rapid fracture
Multiple explosion of container
JOB SAFETY ANALYSIS WORKSHEET
Company name: Date:.
Site name:. Permit to work:.
Unit in charge:… Approved by:..
JOB SAFETY ANALYSIS WORKSHEET: WORK AREA – LPG BULLET
Spillage and pipe bursting.
Loading of bullet is up to limit with proper attention
Crack & rupture
Proper inspection and measurement.
Back flow and incident occur.
Proper training to employees and use proper PPEs.
Static electricity generated, leakage, leak & line rupture.
Ground ignitable hazardous waste to prevent spark.
It leads to a violent rupture of the container.
Delay of process, loss of time and material used.
Use of PPEs and proper inspection required.
Failure of bullet
Risk of unconfined external fire or high risk of explosion.
By maintain its proper safety valve.
Bullet is not air tight
Uncontrolled vapors release to ambient or risk of confined external fire.
It can be control by proper design of bullet.
BLEVE, fracture, rupture, boil over.
Provided proper cooling medium.
Bursting of storage tank
Causing shock wave, heat wave, sound wave & shooting out of fragments.
By monitoring temperature and pressure.
SAMPLE CALCULATION OF EXPLOSION
The calculation of explosion storage LPG tank capacity of 56 gallon which is liquefied under the pressure and has above ground storage at ambient temperature has the following details.
Total capacity = 56 gallon
Design Temperature = -42 to 55Â°C, Design Pressure = 20 kg/cm2 or 1.96 mpa Density of LPG = 0.52
Normal Working Pressure = 15 Kg/cmÂ², Tank = Bullets,
Maximum Filling ratio = 80%, Maximum Ambient Temperature = 45Â°C.
Heat of combustion of LPG (Hc)= 46000kj/kg
Capacity of tank= 56 gallon Convert gallon into kg;
1 us gallon =3.78 L
56Ã—3.78= 211.682 L
Density of LPG = 0.52 211.68Ã—0.52=110.073=110kg (Approx)
Calculation for intensity of radiation:
1. td =0.9m1/4
td = Duration of combination
= 0.9(110) 1/4 =2.84 sec
2. D max =5.8m1/3
D max = Diameter of fireball
HFB, Height of fire wall = 0.75Ã— D max
= 20.51 m
Thermal radiation from fire ball or Maximum emitted thermal flux =
E max = 0.133Ã—fÃ—Hc Ã— MF 1/2
Where: – f, Radiant heat fraction = 0.27 P 0.32
As normal bursting pressure is 15kg/cm2 and maximum bursting pressure are 20 kg/cm2 so we are
taking maximum bursting pressure for calculation, so that we can identify the maximum limit of bullet.
Hence PB =20 kg/cm2 or 1.96 mpa (Assume)
f= 0.27(1.96) 0.32
f= 0.27 Ã— 1.240
f=0.33(Radiant heat fraction)
E max =0.0133Ã—0.33Ã—46000Ã— (110)1/2
Radiation received by a target at a distance of 10 m (assumed):
I, Intensity of radiation is expressed as
= Ã—fÃ— Ep
Pw: Partial pressure of water vapors
= 2.02(Pw Ã—X)-0.09
=0.783 atmospheric transmissivity (Dimensional less)
d X= H2 +d2 R
= (20.51)2 +(10) 2 -13.67
= 9.147 m
F, View factor= D2 /4(r + x) 2
= (27.35) 2 / 4(13.67+9.147) 2
= 0.35(View factor)
Ep, Emissive power= Ã—MÃ—Hc /Ã— D2Ã— t
= 0.25Ã—110Ã—46000/(27.35) 2 Ã—2.84
= 189.63kw/m2 I= Ã—fÃ— Ep
= 51.97kw/m2 to target at 10m distance.
The intensity of explosion in which result is 51.97 kW/m2 to target at 10m distance.
Thermal dose: The thermal expression is give by (Explosion) Dose= I4/3 t
Where, I= Incident thermal flux(kw/m2 ) t = Duration of exposure (s)
Dose = (51.97) 4/3 Ã—10 (Assume t= 10 sec)
This result conclude that thermal dose 1914(kW/m2 ) 4/3 s effect is 50% lethality, members of the public.
Thermal dose Fatality criteria (use for fireballs)
Thermal Dose units
(kW/m2 ) 4/3 s
50% lethality, members of the public
50% lethality, offshore workers
These two tables showed the rank and level of hazards:
Very slight harmful
The fire safety preventing methodologies helps in control various kind of hazards & accidents & reduce the rate of loss in many kinds of industries. This approach is to give a systematic way to minimize the fire & explosion hazard in a high risk area. This paper describe the general terms required to create a safe atmosphere under the guidance of various laws related to health & safety. The tool job safety analysis which is used in this paper describes the various levels of risk & hazard which is associated with a LPG bullet or storage tank by using calculation of explosion and the thermal dose. This paper may also helpful to recognizing all possible hazard & their effects on the atmosphere where accidents is happen in any of LPG storage area. There paper is may also represent a good technique to recognize hazard & minimize it.
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