Filtration, Distillation and Gas Absorption Set 1 – Exam

This batch filter is a tank with a false bottom, which supports a filter medium.

Of all continuous filters, this is the lowest in cost per unit area of filter when mild steel is used.

Which of the following is false regarding constant rate filtration?

Which of the following batch filters cannot be used to processa100-kL/hr slurry for recovery of untreated solids?

Which of the following filter media cannot be used for an dilute aqueous mixture at near atmospheric boiling?

In a laboratory experiment, a sample is pumped at a constant pressure drop of 5 psi through 0.25 ft² of filter medium with negligible resistance. After 3 minutes, 1 gallon of filtrate was collected. The slurry is then filtered using a plate-and-frame press with 16 frames, 4 ft² of filtering area per frame, and operating at constant flow rate of 30 gpm. It takes 15 minutes to disassemble, clean, and reassemble the press. The press must be shut down for disassembly when the pressure difference builds up to 10 psi.  What is the net filtration rate in gpm for the plate-and-frame filter press?

Which of the following will increase HETP?

To reduce the required flow rate of stripping agent, which of the following operations can be done to optimize the stripping factor?

A packed absorption tower has straight operating line and equilibrium curve with a Henry’s constant of 2.81 and without heat effects. What is the number of overall gas-phase mass transfer units if Y₁ = 0.25, Y₂ = 0.05, and X₂ = 0.01 if L_M/G_M is 4?

It is desired to absorb 90% of the acetone in a gas containing 1.0% mol acetone in air in a countercurrent stage tower. The total inlet gas flow to the tower is 30 kg mol/hr, and the total inlet pure water flow to be used to absorb the acetone is 90 kg mol H₂O/hr. The process is to operate isothermally at 300 K and a total pressure of 101.3 kPa. The equilibrium relation for the acetone in the gas-liquid is y_A = 2.53x_A. Determine the number of theoretical stages required for this separation.

Ammonia in air is being absorbed using pure water at 25 °C and 1 atm abs in a tower with 1-in metal Pall rings. The feed rate is 1440 lb_m/h and contains 0.03 mol fraction of ammonia in air. The liquid to gas mass flow rate ratio is 2.

Calculate the flooding velocity.

Ammonia in air is being absorbed using pure water at 25 °C and 1 atm abs in a tower with 1-in metal Pall rings. The feed rate is 1440 lb_m/h and contains 0.03 mol fraction of ammonia in air. The liquid to gas mass flow rate ratio is 2.

Determine the tower pressure drop at 50% of the flooding velocity.

Ammonia in air is being absorbed using pure water at 25 °C and 1 atm abs in a tower with 1-in metal Pall rings. The feed rate is 1440 lb_m/h and contains 0.03 mol fraction of ammonia in air. The liquid to gas mass flow rate ratio is 2.

Solve for the tower diameter at 50% of the flooding velocity.

Which of the following is not a consideration to use a partial condenser in a distillation process?

For a T-x-y phase diagram, what is the horizontal line that defines the temperature and intercepts the equilibrium curves?

Which of the following is true at minimum reflux ratio?

The optimum feed-stage location will result to

What method considers variable molar overflowby employing energy balances with anenthalpy-concentration diagram?

A mixture of benzene and toluene is to be separated at 1 atm into a liquid distillate and a liquid bottoms product of 99.9% and 0.1% mol, respectively. At the top of the column, α is 2.53 with benzene as the lighter species, which has a K nearly equal to 1.

Using a reflux ratio of 1.88, determine the additional stages for the rectifying section from y_i+1 = 0.982.

A mixture of benzene and toluene is to be separated at 1 atm into a liquid distillate and a liquid bottoms product of 99.9% and 0.1% mol, respectively. At the top of the column, α is 2.53 with benzene as the lighter species, which has a K nearly equal to 1.

In the said section, what fraction of toluene in the entering vapor is not absorbed?