# I B.Tech Regular Examinations, May/Jun 2008

# PROCESS ENGINEERING PRINCIPLES

# SET-IV

1. (a) Describe the membrane separation process.

(b) What are the various polymeric materials that can be used as membranes in the membrane separation process?

2. (a) An empirical equation for calculating the inside heat transfer coefficient, hi,

for the turbulent flow of liquids in a pipe is given by:

hi = 0.023 G0.8K0.67C0.33, p/D0.2?0.47

where

hi = heat transfer coefficient, Btu/(hr)(ft)2(0F)

G = mass velocity of the liquid, lbm/(hr)(ft)2

K = thermal conductivity of the liquid, Btu/(hr)(ft)(0F) C

p = heat capacity of the liquid, Btu/(lbm)(0F)

m = Viscosity of the liquid, lbm/(ft)(hr)

D = inside diameter of the pipe, (ft).

i. Verify if the equation is dimensionally consistent.

ii. What will be the value of the constant, given as 0.023, if all the variables in the equation are inserted in SI units and hi is in SI units.

(b) Write the dimensions for the following in S.I.

i. kg/m3

ii. N/ m3

iii. Watt

iv. J/kg v. m.m.kg.m.s/s.m3.kg.

(c) Convert 80 degree celcius into degree fahreinheit and 120 degree fahreinheit into centigrade celcius.

(d) Calcium carbonate is a naturally occuring white solid used in the manufacture of lime and cement. Calculate the number of lb mols of calcium carbonate in:

i. 50 g mol of CaCO3.

ii. 150 kg of CaCO3.

iii. 100 lb of CaCO3.3.

(a) Water at 60oC is pumped from a reservoir to the top of a mountain through a 15 cm pipe at a velocity of 3.5 m/s. The pipe discharges into the atmosphere at a level of 1000 m above the level in the reservoir. The pipe itself is 1500m long. If the overall efficiency of the pipe is 65 %. Calculate the power requirement?

(b) Explain the concept of hydrostatic pressure.

4. Describe the concept of velocity profiles of a fluid in between two plates, one is stationary and the other moving with the velocity u.

5. (a) Briefly explain Reynold’s number and its importance.

(b) Distinguish between laminar flow and turbulent flow Write briefly on the following:

i. Friction factor chart

ii. Velocity distribution in laminar flow

iii. Velocity distribution in turbulent flow.

6. (a) Derive relations for Reynolds number and friction factor and establish the Ergun equation for single-phase flow of fluid through packed bed.

(b) A mixture of vapors pass through a packed bed of glass spheres having density 2.4 g/cc each of diameter 0.5 cm. The pressure drop due to the flow is 4000N/m2. The height of packed bed is 1.85 m. The density and viscosity of the vapor mixture are 3.8×10?3 g/cc and 0.015 cP respectively.

Data:

Cross sectional area of the packed column tube = 0.09 m2 Bed porosity = 0.4 Find the mass flow rate of the vapor mixture.

7. A differential manometer is used to measure the pressure drop in a pipeline conveying methane gas at 20oC and 1 atm pressure. The two liquids in the differential manometer are kerosene (specific gravity 0.82) and water. The inside diameter of the reservoirs and the U-tube manometer are 5cm and 0.5cm respectively. If the reading in the manometer is 15cm, calculate the pressure difference indicated, when the change in levels in the reservoir

(a) is neglected and

(b) is taken into account.

8. (a) Briefly explain the situation under which vane pumps are used.

(b) Explain the construction and working of reciprocating pump and rotary pump.