Biomass Furnace PAES 242-243:2010

Question 1

organic materials used as renewable source of energy like wood chips, corncobs and rice
hulls, etc.

Answer 1

biomass

Question 2

enclosed structure for intense heating by fire using any biomass like woodchips, corncobs and
rice hulls as fuel

Answer 2

biomass furnace

Question 3

fire resistant surface located at the heating chamber of the biomass furnace

Answer 3

hearth

Question 4

materials to be processed (i.e. dried, burned, melted, etc.) using biomass furnace

Answer 4

workload

Question 5

framework of metal bars or fire bricks used to hold biomass fuel in furnace for more efficient
combustion

Answer 5

grate

Question 6

Flue gas and other products of combustion goes into the dryer.

Answer 6

Direct-fired biomass furnace

Question 7

Biomass fuels are fed on the combustion chamber in cyclonic manner using a blower. The
biomass fuels in this type of furnace are burned while in suspension.

Answer 7

Cyclonic

Question 8

Biomass furnace with combustion chamber that have stair-liked arrangement of grate

Answer 8

Step-grate

Question 9

Biomass furnace that uses gravitational force on feeding the biomass fuel.

Answer 9

Gravity

Question 10

This type of biomass furnace shall use a heat exchanger to prevent flue gas and other
products of combustion to go with the drying air.

Answer 10

Indirect-fired biomass furnace

Question 11

Uses ambient air to be heated inside or outside the heat exchanger and be used as drying air.

Answer 11

Dry type biomass furnace

Question 12

Uses hot fluid as medium of heat transfer

Answer 12

Wet type biomass furnace

Question 13

Heat resisting lining of the furnace using layer/s of fire bricks

Answer 13

Brick lining

Question 14

Heat resisting lining of the furnace using ceramic materials

Answer 14

Ceramic fiber lining

Question 15

Heat resisting lining of the furnace using aggregates and bonding agent(s)

Answer 15

Monolithic lining

Question 16

Consist of course and fine grains with suitable bonding cement. These are poured in place
using molds or pouring forms after mixing with water.

Answer 16

Castable refractory

Question 17

Kind of castable refractory mortar with a consistency that makes it easy to trowel into place.
These are very useful for patching and for shaping complex surfaces.

Answer 17

Trowelable refractory

Question 18

Contain a binder material, and are tempered with water so that they have suitable plasticity
for pounding or ramming into place.

Answer 18

Plastic refractory

Question 19

Similar to that of plastic refractory but stiffer.

Answer 19

Ramming refractory

Question 20

Tempered with water and/or with a binder added for softer plasticity and permits patching in
place.

Answer 20

Patching refractory

Question 21

Have course and fine refractory grains and bonding agents, suitable for installation with a
gunning machine.

Answer 21

Gunning refractory

Question 22

Can be injected in a slurry state into small places such as gaps and wide cracks, and for filling
molds with narrow passageways.

Answer 22

Injection refractory

Question 23

Castable refractory materials that should be vibrated to fill all the voids in a mold.

Answer 23

Vibratable refractory

Question 24

Form of a thin slurry that can be brushed onto or otherwise coated on the working surface of
other refractory.

Answer 24

Coating refractory

Question 25

Finely ground refractory materials that, when tempered with water, become trowelable for bonding layered-up refractory shapes.

Answer 25

Refractory mortars

Question 26

Single layer heat resisting lining of the combustion chamber and walls shall be able to withstand the operating temperature of at most ________.

Answer 26

760 °C (1400 °F).

Question 27

Biomass furnace that is operating with higher temperature than 760 °C (1400 °F) shall have a ____.

Answer 27

multi-layer wall of hearth.

Question 28

Insulation shall be made of fireproof materials like ceramic fiber paper or ceramic wool, _____ magnesia, rock wool and/or mineral wool. It shall be placed between wall linings and steel frame of the biomass furnace

Answer 28

85%

Question 29

Angle of Repose (Cornhub)

Answer 29

30°-36°

Question 30

Angle of Repose (Ricehull)

Answer 30

35°-50°

Question 31

Combustion chamber shall have a force draft blower and/or passages/opening for air inlet to ensure the complete burning of biomass fuel. For rice hull furnace, this blower or chimney shall be able to support combustion and sustain temperature of __________ to _____ avoid crystallization of silica and caking. (Nguyen, 1995)

Answer 31

700 °C to | 750 °C

Question 32

The center to center distance of the heat exchanger tubes installed shall be more than _____ times the tubes outside diameter.

Answer 32

1.25

Question 33

Heating system efficiency of the furnace shall be at least ____ for direct-fired and _____ for indirect-fired

Answer 33

65% | 50%

Question 34

Burning efficiency of the biomass furnace shall be at least ____.

Answer 34

95%.

Question 35

Furnace efficiency shall be at least ___

Answer 35

65%

Question 36

ratio of the actual and the theoretical heating value of fuel, expressed in percent

Answer 36

burning efficiency

Question 37

ratio of the heat transferred and heat available in biomass furnace, expressed in percent

Answer 37

furnace efficiency

Question 38

heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas without temperature change

Answer 38

latent heat of vaporization

Question 39

distance between the horizontal supporting plane surface and the horizontal plane touching the uppermost part of the biomass furnace. NOTE: All parts of the biomass furnace projecting upwards are contained between these two planes.

Answer 39

overall height

Question 40

distance between the vertical planes at the right angles to the median plane of the biomass furnace and touching its front and rear extremities. NOTE: All parts of the biomass furnace, in particular, components projecting at the front and at the rear are contained between these two planes. Where an adjustment of components is possible, it shall be set at minimum length.

Answer 40

overall length

Question 41

distance between the vertical planes parallel to the median plane of the machine, each plane touching the outermost point of the biomass furnace on its respective side. NOTE: All parts of the biomass furnace projecting side wards are contained between these two planes

Answer 41

overall width

Question 42

heat absorbed or evolved by a substance during a change of temperature that is not accompanied by a change of state

Answer 42

sensible heat

Question 43

ratio of actual and theoretical heat supplied by the fuel to the furnace, expressed in percent

Answer 43

heating system efficiency

Question 44

Moistute Content Corn cobs ____ (maximum) Rice hulls___ (maximum)

Answer 44

10% | 7%

Question 45

Moistute Content Corn cobs ____ (maximum) Rice hulls___ (maximum)

Answer 45

10% | 7%

Question 46

Test duration shall be _______ after steady state operation and needed measurements (heated air temperature from blower, air flow rate from blower and ambient air temperature) shall be obtained and recorded every ________ interval.

Answer 46

two hours | ten minutes

Question 47

Three- _____ samples of biomass fuel shall be randomly collected to be analyzed in the laboratory.

Answer 47

50 g

Question 48

The samples shall be totally burned using electric furnace for _______ Temperature.

Answer 48

5 hours at 1000°C