Book 1 Chapter 19: Introduction To Thermoil Heaters & Systems Flashcards
A hot oil heating system is similar in principle to:
A) A hot water heating system
B) An oil refinery
C) A condensate return system
D) A firetube boiler burner
A) A hot water heating system
Radiant type oil heaters for a hot oil system have:
A) An efficiency of about 75 to 85%
B) Combustion gases flowing across tubes
C) Tubes containing fins on their outer surfaces
D) Efficiencies of about 45%
D) Efficiencies of about 45%
Hot oil may coke in the heater tubes if:
A) Stack temperature gets too high
B) Oil temperature exceeds 350ºC (662ºF)
C) A tube should develop a leak
D) Furnace temperature drops too low
B) Oil temperature exceeds 350ºC (662ºF)
Hot oil circulating pumps:
A) Are positive displacement units
B) Are usually single stage centrifugal units
C) Must be capable of temperatures above 500ºC (932ºF)
D) Need not be kept hot if on standby
B) Are usually single stage centrifugal units
The type of hot oil system heater which is most efficient is the:
A) Radiant
B) Convection
C) Combined conduction and convection
D) Combined radiation and convection
D) Combined radiation and convection
When shutting down a hot oil system, the oil is circulated in order to prevent:
A) Uneven cooling of the oil
B) Oil viscosity becoming too low
C) Over-pressurization of the heater
D) Hot spots from forming
D) Hot spots from forming
During shutdown, hot oil heater pilots and main burners are checked for:
A) Cleanliness
B) Flame pattern
C) Temperature
D) Pressure
E) Setting
A) Cleanliness
A hot oil system pump inlet is located:
A) Above the surge tank
B) Level with the surge tank
C) At the side of the tank
D) Inside the surge tank
E) Below the surge tank
E) Below the surge tank
Low hot oil flow shutdowns (FSDL) are usually installed on the:
A) Pump discharge line
B) Inlet line of the oil heater
C) Surge tank line
D) Pump inlet line
E) Outlet line of the oil heater
E) Outlet line of the oil heater
Steam which comes in contact with people is called:
A) Treated steam
B) Low temperature superheated steam
C) Clean steam
D) Disinfected steam
E) Low flow steam
C) Clean steam
The kind of pump normally used with a hot oil system is a:
A) Multistage reciprocating pump
B) Conventional, single stage centrifugal pump
C) Regenerative pump
D) Rotary screw pump
E) Sliding vane, volute pump
B) Conventional, single stage centrifugal pump
_________ are required to prevent oil from spreading beyond the confines of a heater in the event of a ruptured tube.
A) Bypass piston
B) Rails
C) Moats
D) Tunnels
E) Dikes
E) Dikes
The inner walls and floor of a furnace of a fired heater are usually lined with:
A) Fibreglass blocks
B) Asbestos blocks
C) Refractory brick
D) Pyrex glass
E) Ceramic tile
C) Refractory brick
A high stack temperature in a hot oil heater may be an indication of:
A) A low oil flow
B) A high oil flow
C) A ruptured tube
D) An increase in fuel gas flow
E) Pump cavitation
C) A ruptured tube
To avoid start-up difficulties in cold weather a thermal fluid must have:
A) A low fire point
B) Methanol injected into it periodically
C) Antifreeze added to it
D) A dehydration system installed in the surge tank
E) A low pour point
E) A low pour point
The convection tubes of a typical up-draft model fired heater are located in the:
A) Waterwalls
B) Stack
C) Superheater
D) Burner windbox
E) Breeching
E) Breeching
Hot oil convection heaters have an approximate efficiency of:
A) 85-95%
B) 80-90%
C) 75-85%
D) 70-80%
E) 55-65%
C) 75-85%
A _______ system uses a thermal fluid in place of steam or water to conduct heat from a central source to other vessels and heating coils in a plant.
A) Cooling
B) Hot oil
C) Gas turbine
D) Condensing
E) Vapour
B) Hot oil
The initial fill of a hot oil system surge tank is done by:
A) Bucket brigade
B) Use of a vacuum pump
C) Pipe line
D) Bulk truck
E) Field pressure
D) Bulk truck
The automatic shutdown devices on a hot oil system are called:
A) Circuit breakers
B) Lock-ups
C) Fail safe locks
D) Interlocks
E) Locksmith
D) Interlocks
Overheated oil in fired heater’s tubes breaks down to form:
A) Ash
B) Paraffin
C) Carbonic acid
D) Clinkers
E) Coke
E) Coke
Blanket Gas is used in storage tanks to prevent contact between the liquids and their vapours in the tank and the outside air. The blanket gas is injected in:
A) The vapour space of the surge tank
B) The flare system
C) The hot oil heaters to remove coke
D) The radiant section to prevent tubes overheating
E) The atmosphere to dilute CO emissions
A) The vapour space of the surge tank
Oils intended for use as heat transfer fluid in a hot oil system should:
A) Be corrosive to metals used in the system
B) Have a high viscosity
C) Have a high vapour pressure at operating temperature
D) Possess low heat transfer characteristics
E) Resist thermal breakdown at normal operating temperatures
E) Resist thermal breakdown at normal operating temperatures
With reference to hot oil systems the acronym AFV stands for:
A) Accelerated fuel valve
B) Automatic fuel valve
C) After flow valve
D) After fuel valve
E) Automatic flow valve
B) Automatic fuel valve
Oils intended for use as heat transfer fluid in a hot oil system should:
A) Have a low vapour pressure at operating temperature
B) Possess low heat transfer characteristics
C) Have a high viscosity
D) Be corrosive to metals used in the system
A) Have a low vapour pressure at operating temperature
HRSG is the acronym for:
A) Hot radiation steam generator
B) Hot recovery system generator
C) Heavy recovery steam grader
D) High recovery system grader
E) Heat recovery steam generator
E) Heat recovery steam generator
While the hot oil heater refractory is being dried out the oil circulating in the tubes should be limited to a temperature rise of not more than ______ per hour.
A) 35ºC
B) 55ºC
C) 25ºC
D) 30ºC
E) 60ºC
B) 55ºC
With reference to hot oil systems the acronym FCV stands for:
A) Full cascade valve
B) Flow control valve
C) Flow cutoff valve
D) Fuel cutoff valve
E) Fuel control valve
B) Flow control valve
Flanges used in hot oil systems should be raised face and suitable _______ gaskets should be used.
A) Metallic
B) Graphite/asbestos
C) Garlock
D) Rubber
E) Cork
A) Metallic
Larger diameter piping (above 25.4mm or 1in) may be _______ pipe.
A) Double extra strong
B) Strong
C) Schedule 1600
D) Schedule 40
E) Schedule 80
D) Schedule 40
One of the weaknesses of the gas turbine is its:
A) Weight to power ratio
B) Thermal efficiency
C) Reciprocating motion
D) Startup time
E) Heavy weight
B) Thermal efficiency
Hot oil circulating pumps:
A) Are positive displacement units
B) Need not be kept hot if on standby
C) Lobe type pumps
D) Must be capable of temperatures above 500ºC (932ºF)
E) Are usually single stage centrifugal units
E) Are usually single stage centrifugal units
