Lesson 2 - Cleaning Systems and Control
This lesson explores the concepts of hygienic design and the Cleaning-in-Place (CIP) systems in the brewery. We examine the nature of soils, the chemicals used to remove them and how we can validate cleaning effectiveness. We also consider the optimisation of modern cleaning systems within the brewery.
Multiple Use Systems
Multi use systems can vary from a single to multiple vessels. They can optionally incorporate heating loops as required and will also have a return pump near the cleaned vessel.
Figure: Multi use hot CIP system
Detergent make-up is via a make-up loop and concentrated detergent is injected from the concentrated chemical supply to the correct conductivity in the detergent tank. Make-up can happen independently of the CIP cycle to save time.
Pre-rinse
Pre-rinse is usually recovered post-rinse water from the previous CIP. On rare occasions pre-rinse is dosed with sacrificial detergent to help remove soil and remove residual 
in the fermenter prior to the main clean. The pre-rinse pumped to the fermenter is typically run directly to drain.
Detergent recirculation
When the required volume of pre-rinse solution has been delivered to the vessel, the pre-rinse is run to drain until a no-flow condition is detected. The detergent solution is then pumped to the tank spray device and pumped back to drain until conductivity rises, at which point the detergent tank is opened and recirculation begins. The conductivity meter is set up to signal at 5 mS (milliSiemens) above the conductivity of the pre-rinse solution.
Post detergent rinse
Fresh water is pumped from the fresh water tank into the fermenter, and the detergent returned into the detergent tank until either the tank is full, or conductivity drops. The recovery tank then opens to allow collection of the residual detergent for the next CIP cycle.
Disinfectant rinsing is performed in the same way as with the single use system.
The sequence of a multiple use CIP plant can be viewed in the following animation. Note, this is for illustrative purposes only and is not a recommendation or endorsement of the supplier’s product: