Book 1 Chapter 19: Introduction To Thermoil Heaters & Systems

Question 1

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

Answer 1

A) A hot water heating system

Question 2

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%

Answer 2

D) Efficiencies of about 45%

Question 3

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

Answer 3

B) Oil temperature exceeds 350ºC (662ºF)

Question 4

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

Answer 4

B) Are usually single stage centrifugal units

Question 5

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

Answer 5

D) Combined radiation and convection

Question 6

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

Answer 6

D) Hot spots from forming

Question 7

During shutdown, hot oil heater pilots and main burners are checked for:
A) Cleanliness
B) Flame pattern
C) Temperature
D) Pressure
E) Setting

Answer 7

A) Cleanliness

Question 8

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

Answer 8

E) Below the surge tank

Question 9

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

Answer 9

E) Outlet line of the oil heater

Question 10

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

Answer 10

C) Clean steam

Question 11

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

Answer 11

B) Conventional, single stage centrifugal pump

Question 12

_________ 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

Answer 12

E) Dikes

Question 13

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

Answer 13

C) Refractory brick

Question 14

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

Answer 14

C) A ruptured tube

Question 15

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

Answer 15

E) A low pour point

Question 16

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

Answer 16

E) Breeching

Question 17

Hot oil convection heaters have an approximate efficiency of:
A) 85-95%
B) 80-90%
C) 75-85%
D) 70-80%
E) 55-65%

Answer 17

C) 75-85%

Question 18

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

Answer 18

B) Hot oil

Question 19

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

Answer 19

D) Bulk truck

Question 20

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

Answer 20

D) Interlocks

Question 21

Overheated oil in fired heater’s tubes breaks down to form:
A) Ash
B) Paraffin
C) Carbonic acid
D) Clinkers
E) Coke

Answer 21

E) Coke

Question 22

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

Answer 22

A) The vapour space of the surge tank

Question 23

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

Answer 23

E) Resist thermal breakdown at normal operating temperatures

Question 24

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

Answer 24

B) Automatic fuel valve

Question 25

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

Answer 25

A) Have a low vapour pressure at operating temperature

Question 26

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

Answer 26

E) Heat recovery steam generator

Question 27

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

Answer 27

B) 55ºC

Question 28

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

Answer 28

B) Flow control valve

Question 29

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

Answer 29

A) Metallic

Question 30

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

Answer 30

D) Schedule 40

Question 31

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

Answer 31

B) Thermal efficiency

Question 32

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

Answer 32

E) Are usually single stage centrifugal units