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Heterogeneous method of approaching towards Hazop study for thermic fluid heater in a manufacturing industry.

INTRODUCTION

Development and concept of thermic fluid heater:

SINCE thermic fluid heaters have found wide application for indirect process heating. Incidents relating to thermal fluid systems are regrettably more common than we might realise and can be extremely serious. The fire and explosion hazards with thermal fluid systems have been re-emphasised by recent incidents. These incidents have a direct bearing on the estimated 4000 UK companies that operate thermal fluid systems. Water or steam can be used as heat transfer fluids but when high temperatures are needed organic fluids like mineral oil which are capable of forming explosive atmospheres are often used. Although fire and explosion hazards of low flash point flammable liquids are generally recognised, similar hazards of high flash point material such as thermal fluids are often missed. These heat transfer fluids are often handled at temperatures above the flash point. Employing petroleum based fluids as the heat transfer medium these heaters provide constantly maintainable temperatures for the user equipment. The combustion system comprises of a fixed grate with mechanical draft arrangements. The modern oil fired thermic fluid heater consists of a double coil three pass construction and fitted with a modulated pressure jet system. The thermic fluid, which acts as a heat carrier is heated up in the heater and circulated through the user equipment. There it transfers heat for the process through a heat exchanger and the fluid is then returned to the heater. The flow of thermic fluid at the user end is controlled by a pneumatically operated control valve based on the operating temperature. The heater operates on low or high fire depending on the return oil temperature which varies with the system load. Thermal oil heaters have been involved in serious accidents abroad. The induction of this equipment in Hong Kong is of relatively recent origin and as such should be operated with great care. The personnel engaged in operation and maintenance of these heaters should be fully conversant with correct operating procedures and safety devices.

Literature Survey:

Glenn E. Mahnken et al [9] investigated the use of case histories to energize your HAZOP in that it explains about the process safety management programs of many companies include formal process hazards analyses, using methods such as hazard and operability (HAZOP) studies and "what-if" reviews, as key elements of these programs. Kletz (1) summarizes the purpose of a HAZOP as follows: "to provide a final check on a basically sound process design, to make sure that no unforeseen effects have been overlooked."

Alison McKay et al [1] has investigated Fire and Explosion Hazards with Thermal Fluid Systems with case studies where explosions have occurred in thermal fluid systems, and the flash point of the thermal fluid was found to have decreased below the operating temperature. The paper emphasises the need to consider thermal fluid systems under the "Dangerous Substances and Explosive Atmosphere" DSEAR regulations, including assessing the fire and explosion risks and identifying where explosive atmospheres may occur. It also highlights the fact that where thermal oils are handled under pressure, explosive mist atmospheres may be formed at temperatures below the flash point. A variety of methods for avoiding fire and explosions in thermal fluid systems is also presented.

Ali Musyafa et al [7] has investigated the Hazard and Operability study in Boiler System of The Steam Power Plant where it found the Pulverize is a major part of the boiler combustion system and an important part in the system of steam power plant (PLTU). Pulverizer plant serves to break chunks of coal into the coal ash was then fed to the burner. Therefore the boiler has a very high pressure, is inflammable zone and has a dangerous and potentially very high risk, and then the system needs to be investigated. By performing an evaluation and analysis of critical points in the pulverize, boiler, measuring the level of danger and risk that occurs, and examine other possibilities that would occur in the worst condition by using hazard and Operability (HAZOP) studies by recording the deviation values variable process, making the model Fault Tree Analysis (FTA) and to simulate, it can be known the level of hazard and risk systems, so you can make recommendations and created a new work instructions.

Ali Musyafa et al [12] has predicted an risk management and safety system assessment from power plant steam boiler in power systems unit 5, paiton-indonesia where part of the power plant system that has a high risk of danger is a Boiler and therefore in danger of such a system is necessary to study and review of safety systems for the prevention of danger arising in the Boiler. Therefore hazard analysis used in this study using HAZOP. The biggest danger to the entire node is due to the fire. Therefore, an analysis of emergency response plan to respond to events that include fire evacuation maps, duties and responsibilities of each person as well as preventive measures and counter measurement.

Karthika S [10] investigated accident prevention by using HAZOP study and work permit system in boiler in which accidents can never be eliminated completely, employers can prevent many of the injuries and fatalities that occur each year. HAZOP study provide a safe system of work during inspection, maintenance operation especially in boilers, through that work permit system formed to prevent the accident. When, in a workplace, a hazard has been identified and the risk to health assessed, an appropriate prevention or control strategy is required. Here it tells the fact of preparatory work is more important than the work itself.

L. Pugi et al [13] has investigated a thermo-hydraulic tool for automatic virtual HAZOP Evaluation Development of complex lubrication systems in the Oil & Gas industry has reached high levels of competitiveness in terms of requested performances and reliability. In particular, the use of HAZOP (acronym of Hazard and Operability) analysis represents a decisive factor to evaluate safety and reliability of plants.

N.A. Siddiqui et al [14] has investigated Risk Management Techniques of HAZOP & HAZID Study Risk assessment and management techniques are used in industrial activities to reduce accidents by applying preventive and protective methods. Recommendations are made on the basis of the findings to improve the installation and make it better and more safe place to work. Attempt has been made to carry out HAZID and HAZOP study thoroughly through the Effluent Treatment Plant (ETP) and recommendations were given to make the plant more safe place to work.

Methodology:

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

Findings:
Table 1: Findings of nodes and intentions of thermic fluid heater

INTENTION 1   DIESEL FEED CIRCUIT TO THERMIC FLUID HEATER

NODE A        Transfer of fuel from storage tank to fuel oil service
              tank

NODE B        Transfer of fuel from fuel oil service tank to thermopac
              heater through fuel oil pre-heater

NODE C        Return of fuel from thermopac heater to fuel oil service
              tank

NODE D        Transfer of smoke from thermopac heater to stack

INTENTION 2   THERMIC FLUID TANK HEATER TO PROCESS (OVEN)

NODE A        Transfer of heated thermic fluid from thermopac heater
              to the process

INTENTION 3   RETURN OF OIL FROM PROCESS TO THERMIC FLUID TANK HEATER

NODE A        Transfer of used oil from oven to de-aerator cum
              expansion tank

NODE B        Transfer of oil from de-aerator cum expansion tank to
              the main circulation pump and to the thermopac heater

NODE C        Top up of shell mineral s2 oil from barrel to the
              expansion tank

NODE D        Transfer of excess oil from expansion tank to
              T.F. storage tank and to main circulation pump through
              make up pump


The figure 1 and 2 shows the process & instrumentation diagram and flow diagram of the complex process of a thermic fluid heater in a manufacturing industry respectively. Based on the diagrams the intention and nodes are found out as shown in table 1 with three intentions and nine nodes respectively. The process thermic fluid heater in this manufacturing industry is used for paint shop areas to dry the wet painted jobs quickly. The process works with the help of shell heat transfer oil, diesel, thermopac burner, de-aerator cum expansion tank, some valves, pipes, flanges, motors, pumps, etc. The diesel is used as the fuel source medium to heat the shell mineral oil. First the diesel is feed to the fuel service tank from the fuel storage tank. Then from the fuel service tank the diesel is passed to the thermopac heater with the help of motorized pump located at the bottom of the thermopac. Before the diesel send to the thermopac burner it is pre heated with the fuel oil pre heater. Once the burner starts the remaining fuel oil is returned to the fuel oil service tank with the help of motorized valve. The burner will take sufficient fuel to heat the mineral oil. The thermopac heater is a closed loop system where the flow rotates the mineral oil till it gets dried. The mineral oil is top up in the expansion tank where it contains oil level scale. The expansion tank is used to expand the oil level where it is integrated with the de-aerator thank where air bubbles present in the oil will be removed in this tank. The expanded oil will enter in to the thermopac heater with the help of main circulation pump. The burner will heat the oil to the set temperature and rotates the oil to the process. In process the heated oil circulates in to oven is compressed by the blower. The wet painted jobs enter in to one side will get dried at the other end with the help of heated oil and blower. The remaining oil gets in to the de-aerator cum expansion tank and the process continues since it is a closed loop system. Excess oil from expansion tank is flowed in to the T.F. Storage tank which is passed to the main circulating pump with the help of a makeup pump. Even after the burner stops the oil is allowed to rotate it it gets cooled down otherwise blockage could obtained. If the oil temperature gets low the burner will start automatically with the electrical interlock system as well as vice versa.

HAZOP Worksheet:

Intention: 1 Diesel Feed Circuit To Thermic Fluid Heater:

[ILLUSTRATION OMITTED]
GUIDE    DEVIATION     CAUSES                 CONSEQUENCE S
WORD

No       No flow       Storage tank empty,    Delay in process/
                       Line blockage, power   production, Large
                       failure, Pump          leakage can lead to
                       failure, Line          fire & explosion by
                       fracture,              near fire source.
                       incorrectly gate
                       valve, burst pipe,
                       large leak.

Less     Less flow     Line restrictions,     Delay in process/
                       filter blockage,       production , minor
                       defective pumps,       leaks could result
                       fouling of gate        in fire capture.
                       valve, minor leaks
                       and tuberculation.

More     More flow,    Increased pumping      Over flow could lead
         Over change   capacity, increased    to fire & explosion.
                       suction pressure,
                       reduced delivery
                       head, greater fluid
                       density, control
                       faults.

Other    Static        Not electrically       Ignition of vapour
than     electricity   grounded, escape of    leads to fire &
                       material through       explosion.
                       cracks of flanged
                       joints.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Flow meter to be       Simplex filter,    8    8    2    128
         installed for every    Gate valve or
         250cm, duplex filter   sluice valve,
         can be installed;      Air vent.
         backup system
         required for power
         failure, Periodic
         maintenance required
         Institute regular
         inspection of
         transfer line.

Less     Install flow meter,                       5    6    5    150
         Clean the filter
         periodically

More     Monitor pump speed                        5    10   5    250
         by tachometer,
         Install high level
         alarm on storage
         tank, install flow
         level meter.

Other    Ensure proper                             2    10   8    160
than     earthing to all
         equipment, pipelines
         and storage tanks;
         ensure the integrity
         of joints and
         earthing continuity
         across flange
         joints, air vent
         pipes to oil fuel
         tanks should be
         fitted with flame
         arresters consisting
         of double wire gauze
         of fine mesh.


Node: A Transfer Of fuel From Storage Tank To Fuel Oil Service Tank:

[ILLUSTRATION OMITTED]

Node: B Transfer Of fuel Fuel Oil Service Tank To Thermopac Heather Through Fuel Oil Preheater:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Service or fuel tank   Delay in burner
                       empty, Line            start up, delay in
                       blockage, power        process, pump gets
                       failure, Pump          hotter, impeller
                       failure, Line          blades can be
                       fracture, fouled       damaged, fire &
                       gate valve, burst      explosion could
                       pipe, large leak,      occur by hot
                       flange leaks.          casings.

Less     Less flow     Line restrictions,     Delay in burner
                       filter blockage,       start up, pumps,
                       defective pumps,       impeller blades
                       fouling of valves,     could be damaged.
                       and tuberculation.

         Less          Generation of vacuum   Delay in
         pressure      condition,             process, leaks could
                       air dissolving in      cause fire &
                       liquid, restricted     explosion
                       pump/compress or
                       suction line,
                       undetected leakage,
                       vessel drainage.

More     More flow     Increased pumping      Leaks obtained
                       capacity, increased    through flanges
                       suction pressure,      could lead to fire &
                       reduced delivery       explosion.
                       head, greater fluid
                       density, control
                       faults condensation,

         More          Surge problems,        Pressure can create
         pressure      specifications of      bursting or rupture
                       contraction &          of pipe lines,
                       expansion of pipes,    damage equipments,
                       vessels, fittings,     instruments, water
                       instruments.           hammer, noise
                                              etc. and cause fire &
                                              explosion.

         More flue     Leakage of heat        Fire & explosion.
         gas           carrier into the
         temperature   system, fouling of
                       combustion chamber
                       and uptake,
                       incorrect air/fuel
                       ratio and blockage
                       of air filter.

Other    Static        Not electrically       Ignition of vapour
than     electricity   grounded, escape of    leads to fire &
                       material through       explosion.
                       cracks of flanged
                       joints.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Flow level meter       Non return         9    10   1    90
         with alarm system to   valve, Check
         be installed every     valve, Duplex
         250cm, periodic        filter, 2-
         checking of pump,      Needle valve,
         periodic maintenance   Angular safety
         required, duplex       valve, Gate
         filter, strainer to    valve, Strainer,
         be cleaned             Interlocks
         periodically.          (Pressure
                                switch high,

Less     Install flow           Temperature        5    5    5    125
         metering valve and     switch high,
         flow meter with        Temperature
         alarm system, clean    indicator,
         filter, strainer       Pressure
         periodically           indicator,
                                Temperature
         Check fuel flow        alarm low,         6    9    4    216
         control system         Temperature
         metering valve, NDT    switch low).
         test to be carried.
         through pressure
         indicator, Install
         flow

More     Install flow                              5    10   5    250
         metering valve and
         flow meter with
         alarm system, clean
         filter, strainer
         periodically

         Check fuel flow                           6    10   4    240
         control system
         through pressure
         indicator, Install
         flow metering valve

         Clean the furnace                         4    8    6    192
         and uptake, adjust
         the air/fuel ratio,
         clean the air filter
         and check for any
         damage of the coil
         tube.

Other    Ensure proper                             2    9    8    144
than     earthing to all
         equipment, pipelines
         and storage tanks;
         ensure the integrity
         of joints and
         earthing continuity
         across flange
         joints.


[ILLUSTRATION OMITTED]

Node: C Return Of Fuel From Thermopac Heater To Fuel Oil Service Tank:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Line blockage, power   Fire & explosion
                       failure,               could occur by hot
                                              casings, nearby heat
                       Line fracture,         source and by
                       fouled gate valve,     burner.
                       non return valve,
                       motorised valve,
                       burst pipe, large
                       leaks in flange and
                       burner leaks.

Less     Less flow     Line restrictions,     Delay in burner
                       filter blockage,       start up, pumps,
                       defective pumps,       impeller blades
                       fouling of valves,     could be damaged.
                       and tuberculation.

         Less          Generation of vacuum   Delay in process,
         pressure      condition,             leaks could cause
                       condensation, air      fire & explosion
                       dissolving in
                       liquid, restricted
                       pump/compress or
                       suction line,
                       undetected leakage,
                       vessel drainage.

More     More flow     Increased pumping      Leaks obtained
                       capacity, increased    through flanges
                       suction pressure,      could lead to fire &
                       reduced delivery       explosion.
                       head, greater fluid
                       density, control
                       faults

         More          Surge problems,        Pressure can create
         pressure      specifications of      bursting or rupture
                       contraction &          of pipe lines,
                       expansion of pipes,    damage equipments,
                       vessels, fittings,     instruments, etc.
                       instruments.           And cause fire &
                                              explosion.

Other    Static        Not electrically       Ignition of vapour
than     electricity   grounded, escape of    leads to fire &
                       material through       explosion.
                       cracks of flanged
                       joints.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Flow level meter       Non return         9    10   1    90
         with alarm system to   valve, Gate
         be installed every     valve, Motorised
         250cm, periodic        valve, Vent,
         maintenance to be
         done, eliminate the    Modulating
         nearby heat source     valve.
         or make some
         substitution
         process, isolate the
         area.

Less     Install flow                              5    5    5    125
         metering valve and
         flow meter with
         alarm system, clean
         filter, strainer
         periodically

         Check fuel flow                           6    9    4    216
         control system
         through pressure
         indicator, Install
         flow metering valve,
         NDT test to be
         carried.

More     Install flow                              5    10   5    250
         metering valve and
         flow meter with
         alarm system, clean
         filter, strainer
         periodically

         Check fuel flow                           7    10   3    210
         control system
         through pressure
         indicator, Install
         flow metering valve

Other    Ensure proper                             2    10   8    160
than     earthing to all
         equipment, pipelines
         and storage tanks;
         ensure the integrity
         of joints and
         earthing continuity
         across flange
         joints.


[ILLUSTRATION OMITTED]

Node: D Transfer Of Smoke From Thermopac Heater To Stack:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Wrong routing, Line    Burner stops if
                       blockage, burst        smoke contained in
                       pipe, large leak,      heater, Production
                       equipment failure      stops.
                       (isolation),
                       isolation in error.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Muffler, bar mesh      Gate valve,        6    3    4    72
         screen to be           Temperature
         provided for clean     switch high,
         burned gas out and     Temperature
         for sound reduction,   indicator,
         gas flow level meter   Capillary
         to be provided.        tubing filled
                                system,
                                Interlocks.


Intention: 2 Thermic Fluid Tank Heater To Process (Oven):

[ILLUSTRATION OMITTED]

Node: A Transfer Of Heated Thermic Fluid From Thermopac Heater To The Process:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Heater tube failure,   Delay in process,
                       line blockage,         production.
                       incorrectly gate,
                       globe valve, burst
                       pipe, large leak,
                       equipment failure
                       (isolation valve,
                       pump, vessel, etc.),
                       incorrect pressure
                       differential,
                       isolation in error.

Less     Less Flow     Dirty filters,         Delay in process,
                       deterioration of       production, if the
                       pump performance and   leakage happens
                       circuit valve          inside the
                       accidentally shut      heater furnace,
                       off, Line              explosion may occur.
                       restrictions, filter
                       blockage, fouling of
                       vessels, valves,
                       density of viscosity
                       changes, minor
                       leaks.

         Less          Ambient conditions,    Quality problem in
         temperature   reducing pressure,     jobs, delay in
                       fouled or failed       process, production.
                       exchanger tubes,
                       loss of heating.

         Less          Generation of vacuum   Delay in process,
         pressure      condition,             production, quality
                       condensation,          problem arises.
                       restricted pump/
                       compressor suction
                       line, undetected
                       leakage, vessel
                       drainage.

More     More Flow     Increased pumping      No problem
                       capacity, increased
                       suction pressure,
                       reduced delivery
                       head, greater fluid
                       density, control
                       faults.

         More          Ambient conditions     Over temperature
         temperature   fouled or failed       could cause rapid
                       exchanger tubes,       deterioration of
                       fire situation         thermal oil, above
                       increases, heater      auto ignition
                       control failure,       temperature could
                       internal fires, and    cause fire &
                       reaction control       explosion.
                       failures.

         More          Blockage in            Generation of heated
         pressure      pipeline, accidental   oil from heater will
                       shut off of circuit    be more, Expansion
                       valves and             of pipe lines could
                       malfunction of         occur.
                       circulating pump
                       relief valve, Surge
                       problems, connection
                       to high pressure
                       system, thermal
                       overpressure,
                       positive
                       displacement pumps,
                       and design
                       pressures,
                       specifications of
                       pipes, vessels,
                       fittings, and
                       instruments.

Other    Thermal       Blocked filters and/   Line/process stops.
than     oil heater    or water in fuel,
         misfire       defective fuel pump,
                       malfunction of
                       burner and defective
                       flame detector.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Thermal oil flow       Gate valve,        9    6    1    54
         limiter to be          Globe valve,
         installed, Flame       Non return
         detector               valve, Needle
         installation will      valve, Pressure
         sense the loss of      indicator,
         fire and actuate the   Temperature
         cut out device to      switch high,
         shut off the fuel      Temperature
         supply to the burner   indicator,
         in order to avoid      Temperature
         any accumulation of    indicator &
         flammable gas/         controller,
         vapour inside the      Temperature
         furnace. Pinch         alarm high,
         valves, flow meter,    Capillary
         strainer to be         tubing filled
         installed, NDT test    system,
         to be done, valve      Interlocks.
         checks to be done.

Less     Flow control valve,                       9    5    1    45
         orifice meter to be
         installed, Expansion
         tank low oil level
         cut out to be
         installed where any
         loss of thermal oil
         due to leakage can
         be indicated by this
         device which will cut
         out the fuel supply
         to the burner. The
         leakage is usually
         found on boiler
         tubes, shaft seals
         of circulating pump,
         pipeline and flanges
         of the system. clean
         filters, check the
         pump speed, motor
         current and pump
         coolant, check the
         circuit valves.

         Periodic maintenance                      4    4    6    96
         of heater, tubes to
         be done

         Safety valve with an                      5    5    5    125
         easing gear is
         usually fitted in
         order to lift the
         valve from its seat.
         When fitted with an
         easing gear, it
         should be actuated
         once a day and the
         valve should be
         tested by oil
         pressure every week.
         Operator should
         check the pressure
         indicator and inform
         to the authority

More     Flow control valve                        5    1    5    25
         to be installed,
         Install reducer/
         expander.

         Thermal oil high                          6    10   4    240
         temperature cut out
         alarm installation
         required. Flue gas
         temperature limiter
         to be installed to
         safeguard against
         thermal overload,
         Periodic maintenance
         of heater, tubes to
         be done

         Isolation valves to                       9    5    1    45
         be placed and
         operated by the
         operator, safety
         valve with an easing
         gear are usually
         fitted in order to
         lift the valve from
         its seat. When
         fitted with an
         easing gear, it
         should be actuated
         once a day and the
         valve should be
         tested by oil
         pressure every week,
         check the pipeline &
         valves and check the
         relief valve.

Other    Clean all filters                         4    4    6    96
than     and drain all the
         water from the
         system, check the
         fuel system and
         flame detector.


Intention: 3 Return Of Oil From Process To Thermic Fluid Tank Heater:

[ILLUSTRATION OMITTED]

Node: A Transfer Of Used Oil From Oven To De-Aerator Cum Expansion Tank:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Line blockage,         Delay in process,
                       incorrectly globe      production, Pipe
                       valve, burst pipe,     expansion,
                       large leak,            tuberculation.
                       equipment failure
                       (isolation valve,
                       pump, vessel, etc.),
                       incorrect pressure
                       differential,
                       isolation in error.

Less     Less Flow     Line restrictions,     Delay in process,
                       filter blockage,       production.
                       fouling of vessels,
                       valves, density of
                       viscosity changes.

         Less          Ambient conditions,    Quality problem in
         temperature   reducing pressure,     jobs, delay in
                       fouled or failed       process, production.
                       exchanger tubes,
                       loss of heating.

More     More Flow     Increased pumping      No problem
                       capacity, increased
                       suction pressure,
                       reduced delivery
                       head, greater fluid
                       density, control
                       faults.

         More          Ambient conditions     Above auto ignition
         temperature   fouled or failed       temperature could
                       exchanger tubes,       cause fire &
                       fire situation         explosion.
                       increases, heater
                       control failure,
                       internal fires, and
                       reaction control
                       failures.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Pinch valves, flow     Globe valve,       7    5    3    105
         meter, strainer to     Safety valve.
         be installed, NDT
         test to be done,
         valve checks to be
         done, flow meter
         with alarm to be
         installed.

Less     Flow control valve,                       4    3    6    72
         orifice meter to be
         installed

         Thermal oil heater                        4    4    6    96
         control installation
         required (when the
         temperature of the
         heater carrier has
         attained the lower
         temperature setting
         limit, the burner
         will again be
         actuated by the
         thermostat),
         Periodic maintenance
         of heater, tubes to
         be done

More     Flow control valve                        5    1    5    25
         to be installed,
         Install reducer/
         expander.

         Thermal oil heater                        5    8    5    200
         control installation
         required (when the
         temperature of the
         heat carrier inside
         the equipment has
         attained the upper
         temperature setting
         limit, the heat
         input will be
         stopped but the
         circulating pump
         continues running),
         flue gas
         temperature limiter
         to be installed to
         safeguard against
         thermal overload,
         Periodic maintenance
         of heater, tubes to
         be done


[ILLUSTRATION OMITTED]

Node: B Transfer Of Oil From De-Aerator Cum Expansion Tank To The Main Circulation Pumpandto The Themopac Heater:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Line blockage,         Delay in process,
                       incorrectly gate,      production.
                       globe valve, burst
                       pipe, large leak-
                       equipment failure
                       (isolation valve,
                       pump, vessel, etc.),
                       incorrect pressure
                       differential,
                       isolation in error.

Less     Less Flow     Line restrictions,     Delay in process,
                       filter blockage,       production.
                       fouling of vessels,
                       valves, density of
                       viscosity changes.

         Less          Ambient conditions,    Quality problem in
         temperature   reducing pressure,     jobs, delay in
                       fouled or failed       process, production.
                       exchanger tubes,
                       loss of heating.

         Less          Generation of vacuum   Delay in process,
         pressure      condition,             production, quality
                       condensation,          problem arises.
                       restricted pump/
                       compressor suction
                       line, undetected
                       leakage, vessel
                       drainage.

More     More Flow     Increased pumping      No problem where
                       capacity, increased    reducer presents.
                       suction pressure,
                       reduced delivery
                       head, greater fluid
                       density, control
                       faults.

         More          Ambient                Above auto
         temperature   conditions fouled or   ignition temperature
                       failed exchanger       could cause fire &
                                              explosion.

         More          Surge problems,        Generation of heated
         pressure      connection to high     oil from heater will
                       pressure system,       be more, Expansion
                       thermal                of pipe lines could
                       overpressure,          occur.
                       positive
                       displacement pumps,
                       and design
                       pressures,
                       specifications of
                       pipes, vessels,
                       fittings, and
                       instruments. tubes,
                       fire situation
                       increases, heater
                       control failure,
                       internal fires, and
                       reaction control
                       failures.

Other    Noise and     Gas or air found in    Tuberculation,
than     vibration     the system, heat       ruptures in pipe
                       carrier                lines, leaks of hot
                       deteriorated, water    oil spread over can
                       found in the system.   affect the nearby
                                              person, property.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Pinch valves, flow     Gate valve,        7    4    3    84
         meter, strainer to     Globe valve,
         be installed, NDT      Strainer,
         test to be done,       Reducer/
         valve checks to be     Expander,
         done.                  Reducer/
                                Expander,
                                Temperature
                                switch high,
                                Temperature
                                indicator,
                                Pressure
                                indicator,
Less     Flow control valve,    Differential       4    3    6    72
         orifice meter to be    pressure switch
         installed              low,
                                Differential
                                pressure alarm
                                low, Interlocks.

         Thermal oil heater                        4    3    6    72
         control to be
         installed, Periodic
         maintenance of
         heater tubes to be
         done

         Operator should                           5    3    5    75
         check the pressure
         indicator and inform
         to the authority

More     Flow control valve                        5    1    5    25
         to be installed,
         Install reducer/
         expander.

         Thermal oil heater                        5    8    5    200
         control to be
         installed, Periodic
         maintenance of
         heater, tubes to be
         done

         Isolation valves to                       8    5    2    80
         be placed and
         operated by the
         operator.

Other    Check the de-                             3    5    7    105
than     aerator and drain
         water in the
         expansion tank,
         check the air vent,
         check the shaft seal
         of the circulating
         pump.


[ILLUSTRATION OMITTED]

Node: C Top Up Of Shell Mineral S2 Oil From Barrel To The Expansion Tank:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Line blockage, large   Delay in process,
                       leak-equipment         production and start
                       failure (isolation     up.
                       valve, pump),
                       incorrect pressure
                       differential,
                       isolation in error.

Other    Expansion     Malfunction of level   Delay in process,
than     tank low      controller and         production
         level         leakage in the
                       system.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Pinch valves, flow     Level switch       4    5    6    120
         meter, strainer to     low, Level
         be installed, NDT      Alarm low,
         test to be done,       Interlocks.
         valve checks to be
         done, strainer,
         filter can be
         installed.

Other    Check the level                           2    5    8    80
than     controller and check
         for any leakage of
         the whole system.


[ILLUSTRATION OMITTED]

Node: D Transfer Of Excess Oil From Expansion Tank To T.F. Storage Tank And To Main Circulation Pump Through Make Up Pump:
GUIDE    DEVIATION     CAUSES                 CONSEQUENCES
WORD

No       No flow       Line blockage,         Delay in process,
                       incorrectly gate,      production.
                       globe valve, burst
                       pipe, large leak,
                       equipment failure
                       (isolation valve,
                       pump, vessel, etc.),
                       incorrect pressure
                       differential,
                       isolation in error.

Less     Less Flow     Line restrictions,     Delay in process,
                       filter blockage,       production.
                       fouling of vessels,
                       valves, density of
                       viscosity changes.

         Less          Ambient conditions,    Quality problem in
         temperature   reducing pressure,     jobs, delay in
                       fouled or failed       process, production.
                       exchanger tubes,
                       loss of heating.

         Less          Generation of vacuum   Delay in process,
         pressure      condition,             production, quality
                       condensation,          problem arises.
                       restricted pump/
                       compressor suction
                       line, undetected
                       leakage, vessel
                       drainage.

More     More Flow     Increased pumping      No problem where
                       capacity, increased    reducer presents.
                       suction pressure,
                       reduced delivery
                       head, greater fluid
                       density, control
                       faults.

         More          Ambient conditions     Above auto ignition
         temperature   fouled or failed       temperature could
                       internal fires, and    cause fire &
                       reaction control       explosion.
                       failures. exchanger
                       tubes, fire
                       situation increases,
                       heater control
                       failure,

         More          Surge problems,        Generation of heated
         pressure      connection to high     oil from heater will
                       pressure system,       be more.
                       thermal
                       overpressure,
                       positive
                       displacement pumps,
                       and design
                       pressures,
                       specifications of
                       pipes, vessels,
                       fittings, and
                       instruments.

GUIDE    RECOMMENDED ACTION     PRESENT SYSTEM     O    S    D    RPN
WORD

No       Pinch valves, flow     Gate valve,        8    5    2    80
         meter, strainer to     Globe valve,
         be installed, NDT      Non return
         test to be done,       valve, Strainer,
         valve checks to be
         done.                  Reducer/
                                Expander,
                                Drain valve.

Less     Flow control valve,                       5    5    5    125
         orifice meter to be
         installed

         Thermal oil heater                        4    4    6    96
         control to be
         installed, Periodic
         maintenance of
         heater tubes to be
         done

         Operator should                           4    3    6    72
         check the pressure
         indicator and inform
         to the authority

More     Flow control valve                        5    1    5    25
         to be installed,
         Install reducer/
         expander.

         Thermal oil heater                        5    8    5    200
         control to be
         installed, Periodic
         maintenance of
         heater, tubes to be
         done

         Isolation valves to                       6    4    4    96
         be placed and
         operated by the
         operator.


Risk priority number:

Each failure (mode) has an assigned severity, probability or occurence and detectability values. This common approach uses the following qualitative scale for ranking.

* The severity score (S) is an integer between 1 and 10, where the most severe is a 10

* The probability or occurence score (P or O) is an integer between 1 and 10, where the highest probability or occurence is a 10

* The detectability score (D) is an integer between 1 and 10 where most difficult to detect is a 10.

Here the RPN is not a measure of risk, but of risk priority. Through the HAZOP worksheet it is seen that the high temperature and high pressure created at the nodes A, B, C of intention 1 and node A of intention 2 of thermic fluid heater process should be taken more care to avoid those type of accidents and hazards happening in future. Thus HAZOP of qualitative approach is shown with great intention of risk priority number as a quantitative manner.

Conclusions:

After the usage of HAZOP studies in thermic fluid heater we found that maximum potential danger occurs in the area of diesel pipe lines and burner areas, care must be taken based on the given recommendations provided and periodic check up of equipment and maintenance to be carried at regular intervals to avoid the dangerous fire hazards accident happening in future. Thus HAZOP studies makes easier to show the complexity process of thermic fluid heater in a detailed manner with making process simple with the help of guide words, deviations, and also makes HAZOP of qualitative approach in to quantitative manner to show the impact factor of thermic fluid heater process with the help of risk priority number.

REFERENCES

[1.] Alison Mckay and Richard Franklin, 2011. Fire and explosion hazards with thermal fluid systems. Symposium Series No. 156 Hazards XXII.I ChemE.

[2.] Wassila Benaissa, B., A. Nadine Gabas, A. Michel Cabassud, B. Douglas Carson, A. Se' bastien Elgue, B. Michel Demissy, 2006. Evaluation of an intensified continuous heat-exchanger reactor for inherently safer characteristics, INERIS (Institute National de Environment Industrial et des Risques).

[3.] Bodkhe, R.G., Y.Y. Nandurkar, S.S. Akant, S.L. Bankar, 20140. Performance Analysis of Separating and Throttling Calorimeter to Determine Quality of Steam on Thermax Diesel Fired Water Tube Boiler. International Journal of Research in Engineering and Applied Sciences (IJREAS), 02: 01.

[4.] Triloki Nath Mishra, 2015. Modelling and CFD Analysis of Tube in Tube Helical Coil Heat Exchange, International Journal of Science and Research (IJSR), 4: 8.

[5.] Atul N. Pote1, Pramod R. Pachghare2, 2015. Experimental Analysis on Thermal Performance of Closed Loop Pulsating Heat Pipe Using Zno/Water Nano fluid, International Journal of Science and Research (IJSR), 4: 5.

[6.] Jorge Sanchez, 2009. SIL Application in Burner Management Systems--A Case Study: Thermal Burner, Safety Control & Instrumentation Systems Conference--IDC Technologies.

[7.] Ali Musyafa, Hardika Adiyagsa, 2012. Hazard and Operability study in Boiler System of The Steam Power Plant, IEESE International Journal of Science and Technology (IJSTE), 1(3)1-10 ISSN : 2252-5297.

[8.] Christopher Ian Wright, 2014. Thermal heat transfer fluid problems following a system flush with caustic and water, Elsevier, Case Studies in Thermal Engineering, 2: 91-94.

[9.] Glenn, E., 2001. Mahnken, Use Case Histories to Energize Your HAZOP.

[10.] Karthika, S., 2013. Accident Prevention by using HAZOP Study And Work Permit System In Boiler, International Journal of Advanced Engineering Research and Studies, IJAERS/Vol. II/ Issue II.

[11.] Tony Ennis, 2009. Safety In Design Of Thermal Fluid Heat Transfer Systems, Symposium Series No. 155 Hazards XXI, IChemE.

[12.] Ali Musyafa, Luluk Kristianingsih, 2013. Risk Management and Safety System Assessment from Power Plant Steam Boiler in Power Systems Unit 5, Paiton-Indonesia, Australian Journal of Basic and Applied Sciences, 7(11): 349-356.

[13.] Pugi, L., R. Conti, A. Rindi, S. Rossin, 2014. A thermo-hydraulic tool for automatic virtual HAZOP evaluation, metrology and measurement systems, XXI(4): 631-648.

[14.] Siddiquia, Dr. N.A., 2014. Abhishek Nandana, Madhuben Sharmaa, Abhinav Srivastavaa, Risk Management Techniques HAZOP & HAZID Study, international journal on occupational health & safety, fire & environment--allied science ISSN 2349-977x 1(1): 005-008.

(1) A. Aravind. A, (2) Mr. PSS. Srinivasan, (3) Mr. J. Anbarasu, (4) PSS. Srinivasan, (5) K. Visagavel, (6) D. Sakthivel

(1) PG Scholar, Department of Mechanical Engineering, Knowledge Institute of Technology, Tamilnadu, India (2,4,5,6) Faculty of Mechanical Engineering, Knowledge Institute of Technology, Salem, Tamilnadu, India.

(3) Deputy Safety Manager, Department of Industrial Safety Engineering, Royal Enfield (A Unit of Eicher Motors Limited), Thiruvottiyur, Chennai, Tamilnadu, India.

Received 25 April 2016; Accepted 28 May 2016; Available 5 June 2016

Address For Correspondence:

A. Aravind.A, PG Scholar, Department of Mechanical Engineering, Knowledge Institute of Technology, Tamilnadu, India.

E-mail: aravindmct@gmail.com
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Author:A.Aravind, A.; Srinivasan, PSS; Anbarasu, J.; Visagavel, K.; Sakthivel, D.
Publication:Advances in Natural and Applied Sciences
Date:Jun 15, 2016
Words:5544
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