External Reflux Ratio Calculator

✖The External Reflux Flowrate to Distillation Column is the number of moles of condensed top product flowing back into the column as reflux per unit time.ⓘ External Reflux Flowrate to Distillation Column [L₀]			+10% -10%
✖The Distillate flowrate from Distillation Column is the amount of moles of condensed top product (distillate) flowing out from the column per unit time.ⓘ Distillate Flowrate from Distillation Column [D]			+10% -10%

✖The External Reflux Ratio is the ratio of the liquid flowrate from the reflux drum back to the distillation column to the flowrate of distillate taken as product.ⓘ External Reflux Ratio [R]

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External Reflux Ratio Solution

STEP 0: Pre-Calculation Summary

Formula Used

External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column
R = L₀/D
This formula uses 3 Variables

Variables Used

External Reflux Ratio - The External Reflux Ratio is the ratio of the liquid flowrate from the reflux drum back to the distillation column to the flowrate of distillate taken as product.
External Reflux Flowrate to Distillation Column - (Measured in Mole per Second) - The External Reflux Flowrate to Distillation Column is the number of moles of condensed top product flowing back into the column as reflux per unit time.
Distillate Flowrate from Distillation Column - (Measured in Mole per Second) - The Distillate flowrate from Distillation Column is the amount of moles of condensed top product (distillate) flowing out from the column per unit time.

STEP 1: Convert Input(s) to Base Unit

External Reflux Flowrate to Distillation Column: 6.5 Mole per Second --> 6.5 Mole per Second No Conversion Required
Distillate Flowrate from Distillation Column: 4.2 Mole per Second --> 4.2 Mole per Second No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

R = L₀/D --> 6.5/4.2

Evaluating ... ...

R = 1.54761904761905

STEP 3: Convert Result to Output's Unit

1.54761904761905 --> No Conversion Required

FINAL ANSWER

1.54761904761905 ≈ 1.547619 <-- External Reflux Ratio

(Calculation completed in 00.004 seconds)

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Created by Vaibhav Mishra

DJ Sanghvi College of Engineering (DJSCE), Mumbai

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Murphree Efficiency of Distillation Column Based on Vapour Phase

LaTeX Go Murphree Efficiency of Distillation Column = ((Average Mole Fraction of Vapour on Nth Plate-Average Mole Fraction of Vapour at N+1 Plate)/(Average Mole Fraction at Equilibrium on Nth Plate-Average Mole Fraction of Vapour at N+1 Plate))*100

Liquid Reflux Flowrate based on External Reflux Ratio

LaTeX Go External Reflux Flowrate to Distillation Column = External Reflux Ratio*Distillate Flowrate from Distillation Column

External Reflux Ratio

LaTeX Go External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column

Overall Efficiency of Distillation Column

LaTeX Go Overall Efficiency of Distillation Column = (Ideal Number of Plates/Actual Number of Plates)*100

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Feed Q-Value in Distillation Column

LaTeX Go Q-value in Mass Transfer = Heat Required to Convert Feed to Saturated Vapor/Molal Latent Heat of Vaporization of Saturated Liq

External Reflux Ratio

LaTeX Go External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column

Internal Reflux Ratio

LaTeX Go Internal Reflux Ratio = Internal Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column

Boil-Up Ratio

LaTeX Go Boil-Up Ratio = Boil-Up Flowrate to the Distillation Column/Residue Flowrate from Distillation Column

External Reflux Ratio Formula

LaTeX Go

External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column
R = L₀/D

What is the importance of Reflux Ratio in Distillation Column?

If reflux ratio is reduced (or if distillate rate D is increased compared to L) the more stages are required. Further reduction in Reflux Ratio leads to a point where infinite stages are required. This condition is known as minimum reflux.
Any Increase in Reflux ratio above this point gives a workable system, upto the point where the reflux ratio reaches infinity and minimum number of stages are required, this condition is known as Total Reflux.

What is the effect of Reflux Ratio on Distillation Operation?

Distillation process is done to achieve a specific level of enrichment. To achieve this enrichment level, one must specify a reflux ratio. Decreasing that reflux ratio (i.e, increasing D), has an advantage that the duty of condenser and reboiler decreases, since the load in distillation column decreases (more mass goes out as D increases) . In other sense, the operating cost of distillation column decreases. However, it would be at expense of less enrichment achieved than required.
Increasing reflux ratio would act in reverse i.e, it would have a disadvantage of increase in duty of condenser and reboiler as load increases. This increases the operation cost of distillation column; however, more enrichment is achieved.

How to Calculate External Reflux Ratio?

External Reflux Ratio calculator uses External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column to calculate the External Reflux Ratio, The External Reflux Ratio formula is defined as the ratio of liquid fed back to the distillation column from the accumulator to the distillate taken out as a product. External Reflux Ratio is denoted by R symbol.

How to calculate External Reflux Ratio using this online calculator? To use this online calculator for External Reflux Ratio, enter External Reflux Flowrate to Distillation Column (L₀) & Distillate Flowrate from Distillation Column (D) and hit the calculate button. Here is how the External Reflux Ratio calculation can be explained with given input values -> 1.547619 = 6.5/4.2.

FAQ

What is External Reflux Ratio?

The External Reflux Ratio formula is defined as the ratio of liquid fed back to the distillation column from the accumulator to the distillate taken out as a product and is represented as R = L₀/D or External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column. The External Reflux Flowrate to Distillation Column is the number of moles of condensed top product flowing back into the column as reflux per unit time & The Distillate flowrate from Distillation Column is the amount of moles of condensed top product (distillate) flowing out from the column per unit time.

How to calculate External Reflux Ratio?

The External Reflux Ratio formula is defined as the ratio of liquid fed back to the distillation column from the accumulator to the distillate taken out as a product is calculated using External Reflux Ratio = External Reflux Flowrate to Distillation Column/Distillate Flowrate from Distillation Column. To calculate External Reflux Ratio, you need External Reflux Flowrate to Distillation Column (L₀) & Distillate Flowrate from Distillation Column (D). With our tool, you need to enter the respective value for External Reflux Flowrate to Distillation Column & Distillate Flowrate from Distillation Column and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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