This calculator is best for 2", 3", 4" or 6" diameter plate reflux columns having 2, 3, 4, 5 or 6 plates installed over a potstill. Plate spacing values can be 4", 6" or 9". Values other than these numbers may also be ok.
Calculations are given for both sieve plates and bubble cap plates. You can specify the hole diameter and number for sieve plates or use the program values. Bubble caps for each size column are standard and specified by the program.
You enter the input data for the column and include an estimated initial distillate rate or an observed initial distillate rate. The calculator will then determine the reflux ratio for this operation. It can also be used to find a distillate rate that will give a certain reflux ratio.
This calculator also gives an estimate of several other operating characteristics for a reflux column with sieve or bubble cap plates using the specified input data. Distillation time starts after the column reaches equilibrium.
The results are for an operation where the watts and reflux ratio are not increased during the run. When they are increased to keep the distillate rate more constant, the time to tails is decreased and tails vapor velocity is increased. Increasing power before the tails will help to prevent weeping.
The run time to reach tails is estimated. Calculations are then made for the amount and % ABV of heads and hearts produced up to the start of tails. The calculations are not to be used for fast strip runs.
The vapor rate to the condenser is calculated from the pot watts and the abv % of the vapor from the top plate or packing. You make an estimate of this abv% in the input data and can update it if needed. A heat loss of 30% is used in the calculation.
For a CM column, you enter an estimate of the Cooling Water Flow Rate then the program can search to find the cw value to match the Condenser Heat Transfer Watts equal to the Heat Transfer Required Watts to condense the reflux. Or, you can use the entered cw flow value.
For a VM or CCVM column, you enter an estimate of the Cooling Water Flow Rate then the program can search and find the value to match the Condenser Heat Transfer Watts equal to 1.2 times the Heat Transfer Required Watts to condense the reflux. This will insure that all the reflux is condensed and subcooled so there is no alcohol vapor escaping through the condenser. Or, you can use the entered cw flow value.
An estimate of the still heat loss is a required input. For very well insulated pot and column, use 20% heat loss. For average insulation or not the pot insulated, use 30% heat loss. For uninsulated stills, use 36% to 40% heat loss.
The results are based on run data from many HD posts, calculations from a simulation of a plated reflux column and established distillation column design equations. Estimates are made for Flooding and Weeping conditions ( Yes / No ) and the plate efficiency of the column. The results can be used to study your operation.
Information about this calculator can be found in the thread "Plate Reflux Column Operating Characteristics".