L1 & 2- Introduction & Equipment for batch processing

Question 1

Why batch over continuous operation

Answer 1

Scale of production- small scale, high value
Variability in production rate- easier to run more/fewer batches than turn up/down continuous
Multi-product manufacture- more than one product per campaign
Conditions of individual batch not affect subsequent
Continuous operation costly if multiple steps & solids
Presence of solids- avoid metering solid flows
High purity- easier in batch
Easily scaled up- more adaptable

Question 2

Jacket adv & dis

Answer 2

Easier for cleaning
Problem as vessel size increases as SA:V decreases

Question 3

Why use baffles?

Answer 3

Baffles improve mixing performance

Mixing energy source of heat- removed by cooling

Question 4

What size batch vessel used?

Answer 4

More cost-effective to use standard batch vessel sizes from manufacturer

Question 5

Filter press (Solid-liquid separation)

Answer 5

Allow constant pressure/flowrate for filtration

Squeezing/pressing to reduce moisture in cake via membrane plates and compressed air applied

Cake washed to displace mother liquor in press

Question 6

Monoplate Pressure Filter/Nutsche Filter

Answer 6

Positive pressure and vacuum can be applied

Heated/cooled to use as reactor - produce dry cake with no mother liquor contamination

Question 7

Centrifuges

Answer 7

Rotational speeds can be higher than continuous

Manual handling of cake

Question 8

Drying types

Answer 8

Most dryers used in batch mode

Fluidised bed, flash, tray, rotary dryers

Question 9

Main heating and cooling equipment

Answer 9

Jacket or internal coils