For liquid-liquid extraction, which flow arrangement is the most efficient and most commonly used?
Explanation
This question tests the understanding of different process flow-schemes for multi-stage extraction and the fundamental reason why countercurrent operation is preferred for maximizing separation efficiency.
Other questions
In the general procedure for separation column design, what is the first step that needs to be calculated?
What is the definition of the net area available for vapor-liquid disengagement (An) for a single-pass plate as described in Section 17.13.2?
For designing separation columns, what is the recommended range of vapor velocity as a percentage of the flooding velocity?
What correction should be applied to the K1 value for flooding velocity estimation if the hole:active area ratio is 0.08, according to the table on page 677?
What is the recommended range for weir height in columns operating above atmospheric pressure?
According to Section 17.13.10, what is the preferred hole size for nonfouling applications on a sieve plate?
What is the normal range for the hole pitch (lp) as a multiple of the hole diameter?
What is the minimum recommended residence time in the downcomer to allow for the disengagement of entrained vapor?
In the plate design procedure, if checking the downcomer backup reveals it is too high, what is the recommended corrective action?
In the plate design calculation in Example 17.6, what was the calculated downcomer backup (hb)?
In Example 17.6, the initial check for weeping showed that the actual minimum vapor velocity was lower than the minimum design velocity. What action was taken to rectify this?
What is the primary advantage of using packed columns over plate columns for handling corrosive liquids?
For a column with a diameter greater than 0.9 m, what is the recommended packing size range?
What is the packing factor (Fp) for 2.0 inch metal Raschig rings according to Table 17.2?
For distillation applications using 38 mm (1.5 in) Pall rings, what is the approximate Height Equivalent to a Theoretical Plate (HETP)?
What is the primary function of an impingement baffle in a shell and tube heat exchanger?
In the TEMA designation for shell and tube heat exchangers, what does the first letter of the three-letter code represent?
What is the recommended tube pitch for a triangular tube arrangement in a shell and tube heat exchanger?
For a shell and tube heat exchanger, what is the typical range for the optimum tube length-to-shell diameter ratio?
What is the main purpose of using baffles in the shell of a shell and tube heat exchanger?
What is the generally considered optimum range for a segmental baffle cut?
Under what condition should an economic exchanger design be reconsidered, based on the temperature correction factor Ft?
When allocating fluids in a shell and tube exchanger, where should the more corrosive fluid be placed?
What is the typical design velocity for liquid process fluids on the tube-side of a shell and tube exchanger?
What is the suggested allowable pressure drop for liquids with a viscosity between 1 and 10 mN s/m2 in a heat exchanger?
In the general equation for turbulent flow heat transfer inside tubes (Nu = C Re^a Pr^b (mu/mu_w)^c), what is the generally accepted value for the Reynolds number exponent 'a'?
For laminar flow (Re less than 2000) inside tubes, what is the recommended minimum value for the Nusselt number if the value calculated by Equation 19.13 is lower?
What is the recommended number of velocity heads to account for pressure losses per pass in a heat exchanger, according to Frank's recommendation cited in the text?
In the Tinker flow model for shell-side analysis, what does stream C represent?
What is the recommended design velocity for vapors at atmospheric pressure on the shell side of a heat exchanger?
What does a TEMA type BEU exchanger signify?
According to the TEMA standards, what is the minimum nominal shell thickness for a 760-990 mm diameter carbon steel pipe shell?
What is the primary disadvantage of a fixed tubesheet (TEMA type BEM) heat exchanger?
In Equation 19.3b for estimating bundle diameter (Db), what does K1 represent?
For a shell and tube exchanger with a triangular pitch of 1.25do, 2 tube passes, and a bundle diameter of 1000 mm with 25 mm tubes, what is the estimated number of tubes (Nt)?
What is the primary reason for using a packed column instead of a plate column for small-diameter columns (less than 0.6 m)?
In packed column design, what does HETP stand for?
What are the recommended design values for pressure drop in packed columns used as absorbers and strippers?
What is the function of a liquid redistributor in a packed column?
What is the general guide for the maximum bed height in a packed column using Pall rings and saddles before liquid redistribution is needed?
In solvent extraction, under what condition might it be more economic than distillation?
In solvent selection for extraction, what is the partition ratio?
On a triangular equilibrium diagram for liquid-liquid extraction, what is the plait point?
What is the typical range for the Height Equivalent to a Theoretical Plate (HETP) in random packings for extraction?
What is the definition of the active area (Aa) for a single-pass plate?
According to the plate design procedure, what is the recommended action if the check for entrainment shows it is too high?
For a stainless steel plate, what is the minimum hole size that can typically be punched?
What is the total plate pressure drop (ht) considered acceptable in the conclusion of the calculation in Example 17.6?
In the final plate specification from Example 17.6 shown in Figure 17.44, what is the specified hole pitch?