Pilot extraction column startup, top interphase level

Start the model Pilot extraction column with default options. The objective is to start and run the column with heavy phase being continuous phase, light phase being dispersed one, and to check material balance.

• Stop the peristaltic feed valves, open emptying valve of gravity feed drums, and check feed tanks holdup (should be 1000 kg). Close the valves and start peristaltic pumps
• Feed the column with 400 kg.h^-1 of heavy phase, and wait until heavy phase level reach the top of the packing
• Decrease heavy phase feed flowrate to 200 kg.h^-1, and set light phase feed flowrate to 180 kg.h^-1
• Check that interphase level stay in the middle of column overhead (between heavy phase inlet and light phase overflow), otherwise control it with the hydraulic seal height on heavy phase draw off (256 cm)
• Wait for the process to reach steady state (use =4X or 8X as necessary)
• Display equilibrium curve in mass ratio units, partition coeficient is Y/X=1
• Display Mac Cabe and Thiele graphic construction in mass ratio (operating line, number of theoretical stages). The yellow point represent column bottom mass ratios, the blue one column overhead
• Calculate mass ratios of input and output, based on mass fraction displayed on synoptic, and check yellow and blue points are correct
• Control that process has reached steady state, and check global and solute mass balance in continuous
• Calculate solute transferred from heavy phase and transferred to light phase (they should be similar)
• Calculate extration yield and compare it with the displayed one
• Stop feeding the column when extract and raffinate drums contain more than 100 kg
• Stop the feed pumps and empty gravity feed drums
• Check global mass balance on the overall operation

Startup with heavy phase dispersed, bottom interphase level

• Feed the column with 400 kg.h^-1 of light phase, and wait until light phase level reach the top of the packing
• Decrease heavy phase flowrate to 250 kg.h^-1, and set heavy phase flowrate to 200 kg.h^-1
• Check that interphase level stay in the middle of column bottom (between light phase inlet and column bottom), otherwise control it with the hydraulic seal height on heavy phase draw off (output heavy flowrate ~180 kg.h^-1, 247.5 cm)
• Wait for the process to reach steady state (use =4X or 8X as necessary)
• Display Mac Cabe and Thiele graphic construction , and check that slope of operating line is below 1, i.e. (pure diluent/pure solvent)=200×(1-0.11)/[250×(1-0.02)]=0.727
• Look at extraction yield, and compare with the one obtained with solvent flowrate of 180 kg.h^-1 and light phase dispersed