Download SGBAU (Sant Gadge Baba Amravati university) B-Tech/BE (Bachelor of Technology) 6th Sem FPOPC Petro Pulp n Paper Technology III Previous Question Paper
11051 : Pulp & Paper Technology - III : 6 PT 04
P. Pages : 4 AW - 3261
Time : Three Hours LI!!!le Max. Marks : 80
Notes : 1 Due credit will be given to neatness and adequate dimensions.
2. Assume suitable data wherever necessary.
3. Diagrams and chemical equations should be given wherever necessary.
4 Illustrate your answer necessary with the help of neat sketches.
5 Use of slide rule logarithmic table, Steam table, Mollier's Chart, Drawing
instrument, Thermodynamic table for moist air, Psychrometric Charts and ?
Refrigeration charts is permitted.
Discuss the reaction, mechanism wherever necessary.
Duhring rule chart, enthalpy concentration chart is permitted.
NS"
SECTION ? A
l. a) A horizontal belt pulp washer is processing 600.0 tonnes per day of (oven dry basis) pulp. 4
The length of workable surface of the belt washer is 10.0 m and width is 8.0 m. Calculate
the washer loading.
b) When fertilizer is used in high quality chemical pulps what problems does paper maker 4
face? -
c) Figure 1 shown below explains the ef?ciency of hydro-cyclones versus reject rate by 3
volume. It is given that AP, =50kPa, AP; =150kPa and AP3 =300kPa. Justify why
ef?ciency falls at AP] and AP3 pressure difference?
A?
.' I 1. 3. 3
? 'm'w: Iv mun:
/ Fig. 1
1 d) How does Pulmac Shive analyser measure the shive count? 2
? 0R
2. a) How would you measure soda losses in washed pulp? Ifthe washers soda losses is high 4
then what does it signify?
b) With the help of a neat graph explain the effect of Kappa No. and minimum reject rate on 5
shive removal ef?ciency of a screen.
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C)
b)
b)
a)
b)
a)
Explain with the help of a neat sketch the mechanism of contamination removal in reverse
centricleaners.
An evaporator is used to concentrate 4536 kg/Hr of 20.0% (wt %) solution of NaOH in
water entering at 60?C (333 K) to a product of 50.0% (wt %) solids. The pressure of
saturated steam used is 172.4 kPa and the pressure in the vapour space of the evaporator is
11.7 kl?a. The overall heat transfer coef?cient is 1560 w / m2 ? k. Calculate the steam used,
the steam economy and the heating surface are in m2 .
When you are concentrating black liquor to high solids of 80.0% then which technical
problems would you have to encounter?
OR
What is boiling point rise in black liquor? How does this affect during concentration of
black liquor?
Why should tall oil soap be removed from black liquor? Figure 2 show below plots the
effec: of residual active alkali on tall oil soap solubility. How would you maintain residual
effec tive alkali content.
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Fig?Z
.
Why would you use mixed feed multiple effect evaporator to concentrate black liquor?
Explain the advantages of using mixed feed arrangement.
How is black liquor ?red inside the recovery furnace? Write :10an the a vantages and
disadvantages of various methods followed.
ch is fume formation taking place in recovery furnace? Write down the chemical reactions
involved during the formation of fume.
How would you supply air in the recovery furnace? While sending air what precautions
would you take?
0R
?11y causticizing ef?ciency of green liquor never reaches 100.0%? Explain with the help
ofcausticizing curve.
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10.
11.
b)
C)
b)
Why green liquor should be ciari?ed and drugs washing undertaken?
Write down the chemical reaction of lime slaker.
SECTION - B
A single effect evaporator is being used to concentrate sul?te spent liquor entering the
evaporator at 300?C with 16.0% concentration (wt %). The concentrated black liquor would
be removed at 50.0% (wt %) concentration. Saturated steam is fed into the evaporator at
186.28 kPa and pressure in vapour space was maintained at 12.33 kPa. The speci?c heat of
black liquor was 2.77kJ/kg.?C and overall heat transfer coef?cient is 1560w/ m2.?C.
Neglecting BPR, heat of concentration calculate the steam consumption, steam econoxhy
and heat transfer area of evaporator. ,
With the help of a neat ?ow diagram explain the chemical recovery process of magnesium
base sul?te spent liquor.
0R
Explain the use of cyclone type direct contact evaporator to concentrate sul?te spent liquor.
Explain the TampeHa-pmcess of converting sul?te green liquor into sul?te cooking liquor.
Write down the elemental analysis of sul?te spent liquor using magnesium base.
Why bleaching of pulp becomes necessary?
How would you measure the brightness of pulp?
If 6.0 gm of wet pulp at 30.0% consistency used upto 23.0 ml of 0.1NKMnO4. Calculate
the theoretical amount of available chlorine required to bleach 2.0 tonnes of wet pulp. Also
calculate the percentage chlorine applied on the pulp during bleaching.
0R
Explain with the help of chemical reaction the bleaching of pulp by chlorine.
Why alkali extraction has to be performed 932:: every cxidativ: bleaching prcxaess?
In descending order write down the effectiveness of bleaching chemicals for particle
bleaching.
Write down the operating parameters of ozone bleaching.
What do you understand by Total Chlorine Free (TCF) bleaching sequence? What are the
bene?ts of TCF bleaching? Write down a TCF bleaching sequence.
What do you understand by reductive bleaching of pulp? Why reductive bleaching is not
preferred for chemical pulps?
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12.
OR
a) What role does magnesium sulphate play during oxygen bleaching of pulp?
b) Write down the typical Absorbablc Organic Halides (AOX) values for Kra? pulp
bleaching ef?uent.
c) Draw the chemical structure of 2, 3, 7, 8 tctrachlorodibenzo - p ? dioxin and 2, 3, 7, 8
tetrac hlorodibenzo ?? p -? furan. Write down the toxicological studies of these two chemicals.
*?i?th??i?
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This post was last modified on 10 February 2020