# JNTU Previous Question Papers

# Process Engineering Principles

# May/Jun-2008 Set-I

1. (a) What are the various unit operations involved in downstream processing?

(b) Explain in detail about the various unit operations involved in process industries.

2. 17.2 Grams of N2O4 gas, when heated to 100oC at 720 mm Hg undergoes 90% dissociation according to the equation N2O4 ! 2NO2. Calculate the volume occupied at 100oC and 720 mm Hg assuming ideal gas law.

3. State and prove Bernoulli’s theorem for incompressible fluid and indicate the corrections necessary for its applications.

4. (a) If the velocity distribution of a fluid over a plate is given by u=(3/4)y-y2 where u is the velocity in metre per sec at a distance of y meters above the plate, determine the shears stress at y=0.15 meters. Take the dynamic viscosity of the fluid as 8.5×10?5 kg-sec/m.

(b) Classify the types of fluid.

5. Write briefly on the following :

(a) Friction factor chart

(b) Velocity distribution in laminar flow

(c) Velocity distribution in turbulent flow

(d) Indicate the difference between skin friction and form friction.

6. Explain

(a) Drag coefficients of typical shapes

(b) Ergun equation.

7. (a) Derive an expression for the pressure difference across two limbs of a differential manometer containing two gauge fluids, mutually immissible. What factors influence the sensitivity?

(b) A simple U-tube manometer is installed across an orifice meter. The manometer is filled with mercury (sp. Gravity =13.6) and the liquid above the mercury is carbon tetrachloride (sp. Gravity =1.6). The manometer reads 300 mm. What is the pressure difference over the manometer in Newton’s per square meter?

8. (a) Explain the construction and working of a volute pump. Explain its function with neat sketches.

(b) A centrifugal pump is to be used to extract water from a condenser in which the vacuum is 640 mm of Hg. At the rated discharge the net positive suction head must be at least 3.0m above the cavitation vapour pressure of 710 mm Hg. If losses in a suction pipe account for a head of 1.5 m. What must be the least height of the liquid level in the condenser above the pump inlet.

(c) Discuss briefly about centrifugal pumps.