Pulp and Paper Multiple Choice Questions on “Wood Chips and Sawdust”.
1. What caused the diminished use of Sawdust?
a) Saw blades have become thinner with more teeth
b) Saw blades have become thicker with no teeth
c) Saw blades have become thinner with less teeth
d) Saw blades have become thicker with more teeth
Answer: a
Clarification: This makes the output Sawdust too small to be used as a fiber source for pulp.
2. Mechanical dis-integrated wood pieces are of size ___________ along the grain.
a) 12 – 25mm
b) 0.3 – 2.00mm
c) 26 – 30mm
d) 9 – 12mm
Answer: a
Clarification: Uniform chip size is very important in chemical pulping because large chips are under cooked.
3. Bark, dirt and other materials should always be kept to a minimum of____________
a) 3% or less
b) 0.5% or less
c) 0.005% or less
d) 0.01% or less
Answer: b
Clarification: If not then they give a dark pulp that cannot be brightened, since lignen must be retained in these pulps.
4. Where are Silos located?
a) Over pile of wood chips
b) Over rotor table
c) Under pile of wood chips
d) Under rotor table
Answer: c
Clarification: It is not visible to the wood area. A large supply assures a constant wood supply to the digesters.
5. Whole tree chips undergo cleaning operation prior to the use
a) True
b) False
Answer: a
Clarification: They are made from entire stem of tree and contains dirt, twigs. Hence, whole tree chips undergo cleaning operation prior to use.
6. Which of the following is an example of residual chips?
a) Chip silos
b) Chips
c) Pulp
d) Sawdust
Answer: d
Clarification: Residue generated by the teeth of the saw, then chemically pupled in continuous digesters with short residence time.
7. Which is the closest average fiber length for a 12mm long chip from Douglas fiber?
a) 6mm
b) 2mm
c) 3mm
d) 13.5mm
Answer: c
Clarification: Since, axis is parallel to fiber orientation. We’ll have reduced average fiber lengths.
8. What is the closest percentage of wood received as chip waste from primary wood process and what percentage is chipped on site?
a) 40% and 60%
b) 60% and 40%
c) 80% and 20%
d) 20% and 80%
Answer: c
Clarification: The more amount is exported from the other parts and nearly 20% is collected from machines around plant.
9. One method used for metering the wood chips into the digesters without constant supervision is with the use of chip silos of capacity __________
a) 1 – 10 tons
b) 10 – 50 tons
c) 11 – 100 tons
d) 50 – 300 tons
Answer: d
Clarification: Chip silos are designed in a way to produce more efficiency, after screening.
10. Fuel value of softwood is less than hardwood.
a) True
b) False
Answer: b
Clarification: The value for softwood is higher due to higher lignen content.
>