Fluidized Bed Combustion Flashcards
State the abbreviation used for fluidized bed combustion.
a) FC
b) FBCB
c) FBC
d) FBBC
e) FB
c) FBC
The abbreviation FGD stands for
a) flue gas desulphurization
b) fuel gauge diameter
c) flow gas density
d) fluid gas detector
a) flue gas desulphurization
State the abbreviation for a “fluid catalytic cracker”.
a) CC
b) FC
c) FCCB
d) CFC
e) FCC
e) FCC
FCC, with regard to the refining industry means
a) Federal Communications Commission
b) Fresh condensate control
c) Fluid catalytic cracker
d) Federated consumer costs
e) Fuel Combustion Code
c) Fluid catalytic cracker
AFBC stands for
a) Alberta/Federal boiler calculations
b) Alberta foot board control
c) after-fired boiler circuitry
d) atmospheric fluidized bed combustion
e) automatically flooded boiler condenser
d) atmospheric fluidized bed combustion
PFBC stands for
a) Provincial/Federal boiler calculations
b) Provincial footboard control
c) pre-fired boiler circuitry
d) petroleum fired boiler control
e) pressurized fluidized bed combustion
d) petroleum fired boiler control
With the AFBC, the combustion air pressure is typically
25 cm of water pressure at the FD fan,16 cm at
the base of the active bed, and _______________ at the
top of the combustion mass.
a) at boiler pressure
b) at flue gas exit temperature
c) negative pressure
d) atmospheric pressure
e) absolute pressure
d) atmospheric pressure
With the AFBC, the three pressure zones are typically as
follows at the FD fan, the base of the active bed, and at
the top of the combustion mass respectively.
a) 25 cm of water pressure, 16 cm and atmospheric
b) 20 cm of water pressure, 14 cm and atmospheric
c) 15 cm of water pressure, 10 cm and below atmospheric
d) 30 cm of water pressure, 20 cm and above atmospheric
e) 40 cm of water pressure, 25 cm and above atmospheric
a) 25 cm of water pressure, 16 cm and atmospheric
In FBC, the fuel content by mass of the turbulent inert material is usually less than a) 5 percent b) 3 percent c) 2 percent d) 4 percent e) 1 percent
c) 2 percent
AFBC units permit the reduction of furnace temperatures from
a) 1600 to 850 degrees Celsius
b) 1800 to 650 degrees Celsius
c) 1700 to 750 degrees Celsius
d) 1550 to 900 degrees Celsius
e) 1350 to 500 degrees Celsius
a) 1600 to 850 degrees Celsius
Reducing furnace bed temperatures by use of AFBC units reduces
as well
a) production of hot flue gases
b) efficiency of operation
c) production of NOx’s
d) the turbulence of the furnace interior
e) the steam generating capacity
c) production of NOx’s
Crushed coal mixed with pulverized limestone in an AFBC unit does what? a) lower the combustion bed temperature b) act as a desulphuring agent c) create the perfect fuel; hydrogen d) pressurizes the fluidized bed e) produces no gaseous effluent
b) act as a desulphuring agent
What is the percentage of SOx reduction which can be gained by adding an excess amount of limestone to the bed of an AFBC unit? a) 40 - 50 percent b) 50 - 65 percent c) 70 - 80 percent d) 80 - 90 percent e) 90 - 95 percent
d) 80 - 90 percent
About the only thing limiting the kind of fuel burned in a
FBC is
a) how well the material has been mixed prior to burning
b) the heating value of the material being burned
c) the amount of slag the fuel will produce
d) the size of the plant using the fuel
e) the size of the burners
b) the heating value of the material being burned
The gradual loss of the fluidized bed in an FBC furnace is called a) attrition b) fluidation c) carryover d) reduction e) starving
c) carryover
The ash content of a fuel which can be burned in a FBC unit and which will not burn successfully in any other type of furnace is a) 10 percent b) 30 percent c) 55 percent d) 60 percent e) 70 percent
e) 70 percent
Large “clinkers” are not produced in FBC furnaces because
of
a) lower furnace temperatures
b) the fluidized bed created by air passage through the furnace
c) the kind of fuel used
d) the introduction of limestone into the combustion mixture
e) not burning gaseous fuels
a) lower furnace temperatures
The reason FBC plants can be built smaller than plants
currently in vogue is because of
a) higher steam temperatures and pressures
b) higher heat transfer rates and the absence of wet
exhaust gas scrubbing equipment
c) lower maintenance costs and the ability to burn a wide
variety of fuels
d) less slag production and the elimination of soot-
blowing equipment
e) the burners being smaller
b) higher heat transfer rates and the absence of wet
exhaust gas scrubbing equipment
Steam generators of the FBC type can be reduced in size by up to a) 35 percent b) 15 percent c) 45 percent d) 25 percent e) 10 percent
d) 25 percent
Because of the one quarter reduction in size of FBC plants a significant saving is gained in a) fuel and waste costs b) material and construction costs c) heat and light costs d) "Clinker" and soot blowing costs e) fuel storage costs
b) material and construction costs
Feedthrough tubes are located?
a) in the furnace windbox
b) in the furnace ceiling
c) in the furnace walls
d) in the corners of the furnace
e) in the furnace bottom
e) in the furnace bottom
An especially important point in the operation of fluidized beds composed of fine particles is a) feedwater temperature b) solids injection rate c) bubble size d) waste solids handling e) the colour of the limestone
c) bubble size
Operating a PFBC furnace at low temperatures results in
a) the formation of “clinkers”
b) a restricted type of fuel used
c) the need for the installation of soot blowers
d) the generation of wet steam
e) steam temperature limited over the period of heat supply
e) steam temperature limited over the period of heat supply
Carryover in FBC units results in
a) lower efficiency and higher costing dust collectors
b) lower furnace temperatures and the need for higher
furnace ceilings
c) lower tube location and higher combustion rates
d) lower steam pressures and higher water temperatures
e) overheating of the breeching
a) lower efficiency and higher costing dust collectors
One way of increasing combustion control at low operating rates
in FBC units is to
a) add fuel gas to the combustion process
b) add more expensive control equipment
c) add hot steam to the fluidized bed
d) add an electrical charge to the pulverized limestone
e) close all the air dampers
b) add more expensive control equipment
To what temperature must the inert bed material of a FBC unit be heated before the introduction of coal to the furnace for burning? a) about 350 degrees Celsius b) about 500 degrees Celsius c) about 600 degrees Celsius d) about 750 degrees Celsius e) about 900 degrees Celsius
c) about 600 degrees Celsius
What is the ignition temperature of coal?
a) 300 degrees Celsius
b) 450 degrees Celsius
c) 550 degrees Celsius
d) 600 degrees Celsius
e) 900 degrees Celsius
d) 600 degrees Celsius
The typical time needed to heat a FBC unit bed to fuel ignition
temperature prior to the introduction of coal is
a) one hour
b) one half hour
c) two hours
d) three hours
e) six hours
a) one hour
Due to various differences in the operation of FBC plants the
following is required:
a) a considerably larger floor space
b) better qualified operators
c) a taller furnace stack
d) using new technology in the construction of boiler tubes
e) a considerably different control system
e) a considerably different control system
In order to get maximum heat transfer in a FBC furnace it is
required to
a) increase the fuel consumption per hour
b) ensure that the boiler tubes are covered by the expanded bed
c) build larger FBC’s
d) add fuel gas to the regular fuel being burned
e) line the floor and ceiling of the furnace with steel plates
b) ensure that the boiler tubes are covered by the expanded bed
