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30 Cards in this Set

  • Front
  • Back

What do the following stand for?


1. FBC


2. AFBC


3. PFBC

1. Fluidity Bed Combustion


2. Atmospheric Fluidized Bed Combustion


3. Pressurized Fluidized Bed Combustion

The elimination of SO2 emissions using AFBC depends on three things.

1. How much limestone is added.


2. The depth of the bed


3. Time in the limestone flux

About 10% limestone reduces SO2 emissions by _____%.

80%

About the only thing that limits the type of fuel burned in a FBC is:


1) How well the material has been mixed prior to burning


2) The size of the burners


3) The amount of slag the fuel will produce


4) The size of the plant using the fuel


5) The heating value of the material being burned

5) The heating value of the material being burned

One method of increasing combustion control at low operating rates in FBC units is to:


1) Add fuel gas to the combustion process


2) Add more expensive control equipment


3) Add hot steam to the fluidized bed


4) Add an electrical charge to the pulverized limestone


5) Close all air dampers

2) Add more expensive control equipment

For effective removal of fine dust, most of the power plants in the world use:


1) Oil wetted fiberglass


2) Electrostatic precipitators and fabric filters


3) Cyclone separators


4) Dust collectors


5) Cyclone separators and filter beds

2) Electrostatic precipitators and fabric filters

A gradual loss of the fluidized bed, including fuel (carbon) particles, is due to:


1) Overheating


2) Carryover


3) Slag content


4) Uplift


5) Priming

2) Carryover

The FD fan power requirements of a FBC unit are how many times more than a normal furnace?


1) 8 times


2) 6 times


3) 1.5 times


4) 3 times


5) 4 times

4) 3 times

State the abbreviation for flue gas de-sulfurization:


1) FD


2) FBGD


3) FBD


4) FGD


5) GD

4) FGD

To what temperature must the inert bed material of a FBC unit be heated before the introduction of coal to the furnace for burning?


1) About 900ºC


2) About 750ºC


3) About 350ºC


4) About 600ºC


5) About 500ºC

4) About 600ºC

Large "clinkers" are not produced in FBC furnaces because of:


1) The kind of fuel


2) Lower furnace temperatures


3) The fluidized bed created by air passage through the furnace


4) Not burning gaseous fuels


5) The introduction of limestone into the combustion mixture

2) Lower furnace temperatures

The introduction of limestone into the combustion mixture An especially important point in the operation of fluidized beds of fine particles is:


1) Waste solids handling


2) Feedwater temperature


3) The color of limestone


4) Bubble size


5) Solids injection rate

4) Bubble size

A design disadvantage of a PFBC furnace is:


1) A great deal of maintenance is required


2) A wide range of fuels cannot be used


3) Erosion and/or corrosion/fouling of turbine blades may occur


4) The boiler is too compact for ease of cleaning


5) Fuel preparation is very complex

3) Erosion and/or corrosion/fouling of turbine blades may occur

What type of research is conducted before large commercial and electric utility plants are built?


1) No particular research


2) Aerospace research


3) Government supervised research


4) Demographic research


5) Pilot plant research

5) Pilot plant research

The efficiency of a combined cycle plant based on fluidized bed combustion (PFBC) is about _____ higher than a conventional pulverized coal plant.


1) 25%


2) 10%


3) 5%


4) 15%


5) 20%

3) 5%

Steam generators of the FBC type can be reduced in size by up to:


1) 15%


2) 45%


3) 10%


4) 25%


5) 35%

4) 25%

Operating a PFBC furnace at low temperatures results in:


1) A restricted type of fuel used


2) The generation of wet steam


3) The need for the installation of soot blowers


4) Steam temperature limited over the period of heat supply


5) The formation of "clinkers"

4) Steam temperature limited over the period of heat supply

Feed through tubes are located in the:


1) Corners of the furnace


2) Furnace walls


3) Furnace bottom


4) Furnace windbox


5) Furnace ceiling

3) Furnace bottom

An especially important point in the operation of fluidized beds of fine particles is:


1) Waste solids handling


2) Feedwater temperature


3) The color of limestone


4) Bubble size


5) Solids injection rate

4) Bubble size

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:


1) 10%


2) 60%


3) 70%


4) 55%


5) 30%

3) 70%

AFBC units permit the reduction of furnace temperatures from:


1) 1 600 to 850°C


2) 1 700 to 750°C


3) 1 550 to 900°C


4) 1 350 to 500°C


5) 1 800 to 650°C

1) 1 600 to 850°C

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:


1) 30 cm of water pressure, 20 cm of water pressure and above atmospheric


2) 25 cm of water pressure, 16 cm of water pressure and atmospheric


3) 40 cm of water pressure


4) 15 cm of water pressure, 10 cm of water pressure and below atmospheric


5) 20 cm of water pressure, 14 cm of water pressure and atmospheric

2) 25 cm of water pressure, 16 cm of water pressure and atmospheric

The typical time needed to heat a FBC unit bed to fuel ignition temperature prior to the introduction of coal is:


1) One hour


2) Six hours


3) Three hours


4) Two hours


5) One half hour

1) One hour

In FBC, the fuel content by mass of the turbulent material is usually less than:


1) 5%


2) 4%


3) 2%


4) 3%


5) 1%

3) 2%

What percentage of SOx reduction that can be gained by adding an excess amount of limestone to the bed of an AFBC unit?


1) 40 - 50%


2) 90 - 95%


3) 50 - 60%


4) 80 - 90%


5) 70 - 80%

4) 80 - 90%

The gradual loss of the fluidized bed in an FBC furnace is called:


1) Fluidization


2) Carryover


3) Starving


4) Attrition


5) Reduction

2) Carryover

In a typical AFBC unit, what depth is the combustion bed kept at?


1) 1.5 metres


2) 2 metres


3) 2.5 metres


4) 3 metres


5) 1 metre

5) 1 metre

What is the ignition temperature of coal?


1) 300ºC


2) 900ºC


3) 450ºC


4) 550ºC


5) 600ºC

5) 600ºC

Carryover in FBC units results in:


1) Overheating of the breaching


2) Lower efficiency and higher costing dust collectors


3) Lower furnace temperatures and the need for higher furnace ceilings


4) Lower tube location and higher combustion rates


5) Lower steam pressures and higher water temperatures

2) Lower efficiency and higher costing dust collectors

For coal containing 5 percent sulphur, how much limestone might be fed to the furnace of an AFBC unit with each tonne of coal?


1) 1 tonne of limestone


2) 1 500 kg of limestone


3) 250 kg of limestone


4) 750 kg of limestone


5) 500 kg of limestone

5) 500 kg of limestone