Explain how the temperature is controlled on the (a) top (b) middle (c) bottom part of the tower in separation systems.

Compare and contrast the three types of plates in plate distillation systems.

Air at Ts passes over a large flat surface that has a dimension of length (L) of 70 cm and a width (W) of 10 cm. The air velocity over it is V and the surface temperature is maintained at Ts =250 oC.
a) For these conditions, what is the heat transfer rate of the large flat surface?

To increase the heat removal rate, a stainless steel (AISI 304) uniform cross sectional rectangular pin fin of a base dimensions of 30 X 30 mm is fixed to the surface which is assumed to remain at Ts =250 oC. The length of the rectangular tip is 100 mm. The tip of the fin is insulated. Assume the convective heat transfer coefficient is the same before and after the addition of the fin.

b) Calculate the temperature at the end of the tip? b) Determine the heat removal rate through the fin. d) Determine the fin effectiveness.

A 600 MW pulverized coal-fired power plant of 40% efficiency uses coal with an ash content of 15% and a heating value of 26,700 kJ/kg. Assume 35% of the ash content goes up the stack as particulate matter in the flue gas. The PM emission is controlled by an ESP which has the following efficiencies and weight distribution in the given size ranges. Find the fly ash emitted in g/s.

Explain the factors affecting the design of reactor systems.

A curtain over a window provides a thermal solution. With your knowledge of the three heat transfer mechanisms describe how a curtain accomplishes its objectives.? (5 pts)

A single stage RO desalination system has the following design data:
-6 3 2
- Water permeability = 2.05xl0 m /m .s.kPa
-5 3 2
- Salt permeability = 2.03x10 m /m .s
- Feed salinity = 38,500 ppm
- Feed flow rate = 3.0 kg/s
- Permeate flow rate = 1.0 kg/s - Feed pressure = 6,600 kPa
- Reject pressure = 6,350 kPa
- Permeate pressure = 101 kPa
Calculate permeate salinity, brine salinity, brine flow rate, and membrane area

The percentage composition by mass of a certian feul is given as C 90%, H 3.5%, O 3% and remainder is incombustible. The fuel is burnt in air and the resulting dry analysis gave the following result by volume: CO2 12.7@, O2 7%, N2 remainder.

a) find the mass of air supplied per kilogram of fuel.

b) Determine the percentage excess air.

1.Explain the methods are used to avoid material hazards.

2. Explain the control measures for overpressure

3. Explain the Process Design Strategies

4.Describe the Flash point and Auto Ignition temperature

5.Explain the causes of Dust explosions in detail.

A diffusion process is run at 1200 ºC with the surface concentration of diffusing atoms kept constant at 1024 atoms/m3 . The process is run for 3 h. If there are no diffusing atoms at the start of the diffusion process inside the diffusing material, at what depth below the surface is the concentration of atoms 1022 atoms/m3 ? The diffusion coefficient at 1200ºC is 7.0 X 10-17 m2 /s.

Calculate the pressure drop across a stenosis of diameter 6mm in the femoral artery in which the crosssection is reduced to one-third of normal if the flow rate through the artery is 50cc/min, and the upstream pressure is 100 mmHg?

A)

Explain what is Fugacity (provide an explanation as detailed as possible). Explain how the fugacity criteria for VLE and Chemical reactions is related to the concept of increasing entropy

B)

What are internal Energy and Enthalpy? how are they related?

C)

A mixture of water-ethanol containing a significant amount of methanol is being distilled (separation by VLE). Someone tells you that the methanol is not a problem because it boils off first as it has a lower boiling point. Is this true? Discuss in detail.

A 2-in-ID wetted wall column is being used to strip CO2 from an aqueous solution by an air stream at 1.0 m/s. At one point in the column, the concentration of CO2 in the air stream is 1.5 mole percent. At the same point in the column, the concentration of CO2 in the water is 0.5 mole percent. Determine the gas-mass-transfer coefficient kG (kg mole/atm-m2-s) and the mass flux at the point in the column. The column is operated at 10 atm and 25°C. The Henry’s constant of CO2 in water at 25°C is 1.64 × 103 atm/mole fraction CO2 in solution.

Write down the equation for the rate of entropy production, diS/dt, for the Bernoulli process 0⇄1 with states 0 and 1, forward rate constant w10 and reverse rate constant w01. Reformulate the equation to eliminate the summation of logarithmic terms. Use your final result to calculate the equilibrium distribution. What are the equilibrium probabilities of states 0 and 1 if w10=w01. Calculate the equilibrium entropy, S°, of the system for w10=w01. 6