# Pune University BE Petrochemical Engineering Elements of Fluidization Engineering Question Papers

B.E. (Petrochemical) ELEMENTS OF FLUIDIZATION ENGINEERING (2008 Course) (Sem. – I) (Elective – I)

Time: 3 Hours]                                                                                              [Max. Marks :100

Instructions to the candidates:

1)            Answer any 3 questions from each section.

2)            Answers to the two sections should be written in separate books.

3)            Neat diagrams must be drawn wherever necessary.

4)            Figures to the right indicate full marks.

5)              Use of logarithmic tables, slide rule, Mollier charts, electronic pocket calculator and steam table is allowed.

6)            Assume suitable data, if necessary.

 Q1) a) b) c) Q2) a) b)

SECTION – I

With help of neat sketches explain the Fluidization process.                              [6]

Explain the liquid like behavior of fluidized bed with help of neat diagram.          [6]

Write a short note on Quality of Fluidization.                                                       [4]

OR

Write the mathematical expression of flow through packed bed. From the base model derive the formula to obtain minimum fluidization velocity in case of a Fluidized Bed.        [8]

Discuss the effects of Temperature and Pressure on Fluidized Bed. [8]

Q3) Calculate the minimum fluidizing velocity umf for a bed of microspherical catalyst of wide size distribution ranging from 0 to 260 pm. Compare the calculated value with the experimentally obtained value of umf = 2.6 cm/s. Data :                                                                 [18]

Solids : ps = 1.83 g/cm3, emf = 0.45 Gas : pg = 1 x 10-3 g/cm3, p = 1.7 x 10-4 g/cm.s.

Size frequency distribution :

 dp (mm) 5 8 10 12 14 15 16 17 18 20 22 24 9.5 p(cm-1) 5 13 23 45 95 135 145 115 88 50 22 12 1

OR

Q4) a) Write a short note on Geldart’s classification of particles and their important characteristics. Provides suitable examples as well. [10]

b) Explain the need for providing distributor in fluidized bed. Name four different types of distributors often used in industrial scale.                                                      [8]

Q5) a) Discuss important characteristics of Multiphase Meters. Name five industrially important multiphase meters and explain operating principle of any one of them with help of suitable example. Provide neat sketches.

[8]

b) Discuss important assumptions of Kunii Levenspiel model. Explain the model with help of suitable example.                                                                                                [8]

OR

Q6) Write short notes on :                                                                                                  [16]

a)            Davidson Bubble.

b)            Coalescence and Splitting of Bubbles in a Densed Bed.

c)            Circulating Bed Fluidized bed.

SECTION – II

Q7) a) Discuss the information needed for designing a fluidized bed. Explain all of them.          [8]

b) With help of mathematical expressions explain gas interchange between bubble and emulsion phase.                                                                                        [8]

OR

Q8) a) What are different variables affecting heat transfer rate in fluidized bed- Explain in brief.                                                                                                             [8]

b) With help of neat sketches explain operations of various types of Fluidized Bed Dryers.                                                                                                        [8]

Q9) a) Discuss the Reactor model for Fine Particle Bubbling Bed.          [9]

b)            In a fluidized bed, mixing is combined effort of plug flow and mixed flow mode- Explain with help of neat diagram.                                                                 [9]

OR

Q10)a) Write a short note on conversion of gas in Catalytic Reaction in a Fluidized Bed Reactor. In this context highlight measures of reaction rate and reactor performance.        [6]

b)            Write short notes on Sintering and Agglomeration.                                    [6]

c)            Write a short note on Slugging fluidized bed.                                               [6]

Q11)a) With help of neat sketches explain operation of a Fluidized Bed Reactor for Polymerization.                                                                                                            [8]

b) Discuss Fluidized bed operation for Combustion of Coal, provide suitable sketches.                                                                                                                     [8]

OR

Q12)Write short notes on :                                                                               [16]

a)            Ranz-Marshal Correlation.

b)            Fluidized bed Catalytic Cracking.

c)            Scale up of fluidized bed reactors.

d)           Free board Region and its usefulness.