No more waste in the dairy
February 2014, Analytical Instrumentation & Environmental Monitoring
CIP cleaning is mandatory for most food processes. But when can the product be used for filling again after cleaning? Every litre of milk lost to wastewater hurts in a dairy.
In CIP cleaning, the system alternates between flushing a base and an acid in water through system parts that have come into contact with the milk. Precise control of phase boundaries is important to carry out this CIP process without wasting time or money:
* During cleaning: when is the rinse water clean and free of milk again so that CIP ends and the next production cycle can start? That saves time and resources. Milk in the rinsing wastewater is indicative of a leak in the process, which leads to product loss and higher costs for wastewater treatment.
* Once production has started again: when is the milk free of rinsing water residue so that filling can start again? That prevents unnecessary product loss and saves money.
The OUSAF11 absorption sensor is well-suited for this process. It determines how much milk is in the rinse water using the method of light attenuation: the more solids in the water, the less light gets through. The sensitivity is adapted to the application using the optical path length (5 or 10 mm). The sensor also has a compact design and the housing for the optical components is made from stable, break-proof Teflon. This means no glass can get into the process.
Too good for the drain
The largest dairy in Costa Rica lost yogurt down the drain every day. This not only wasted product, but also drove up the costs of the wastewater treatment for removing the organic load peaks. Lacking proper measurement instrumentation, the manufacturer did not know how much yogurt was being lost every day. Tests with conductivity measurement failed, since the differences in conductivity between the yogurt and water were too small. The overall situation was very challenging for measurement instruments due to:
* High solids content.
* High temperatures in CIP processes.
* Excessive deposit formation.
The identified solution was the OUSAF11 absorption sensor. It detects product transitions, such as the switch from water to yogurt, by optically determining a fluid's turbidity.
Measurements were accurate and stable and the manufacturer was able to control the process based on reliable values. Less yogurt was wasted and the energy consumption in the wastewater treatment plant’s aeration process decreased dramatically. This resulted in savings of more than R40 000 per week.
For more information contact Jan Swart, Endress+Hauser, +27 (0)11 262 8000, firstname.lastname@example.org, www.za.endress.com