Dairy Plant Equipment, Cleaning, Sanitation and Safety
Dairy Plant Equipment, Cleaning, Sanitation and Safety tests equipment function, CIP control and operator safety. The exam expects you to link equipment design with cleanability and process control.
Equipment and CIP
Know the pasteuriser, homogeniser, cream separator, spray dryer, pumps, valves and tanks. CIP uses circulated cleaning solutions: alkaline detergent for fat and protein, acid for milkstone and mineral scale, then rinse and sanitise. Typical caustic concentration is about 1-2% at 70-80 C; acid concentration is lower. Flow, temperature, concentration and contact time are the four control variables.
Worked example
A CIP tank holds 500 L of 1.5% w/v NaOH solution. NaOH required = 500 × 0.015 = 7.5 kg. If the solution is made from a 50% w/w stock, stock mass = 7.5 / 0.50 = 15 kg. This is a mass balance, not a volume balance; stock density would be needed for volume.
Traps
Caustic does not remove milkstone well; acid does. CIP does not replace manual cleaning of dead ends, gaskets and shadowed surfaces. Do not confuse sanitising with cleaning. Hot caustic is hazardous; use PPE and lockout for rotating equipment. Sanitizer concentration must be measured, not guessed.