While clean in place (CIP) has been the dominant cleaning method for food industries since the second half of 20th century, it’s now facing several challenges. Food processors are questioning how to make it more efficient and less expensive.
The four main parameters in cleaning (knows as TACT) include:
T: Time (total and of each cleaning phase)
A: Action (mechanical effect)
C: Concentration (of cleaning chemicals)
T: Temperature (of water/cleaning chemicals)
There are two main challenges when starting an optimization process. One includes how modifying one of these four parameters will affect hygiene or quality performance. Raising the temperature, for example, will have a bactericidal effect but can increase mineral scaling when cleaning chemicals have a high pH and are loaded with product remains, as the same cleaning chemicals are being recirculated in the CIP process. This situation is very common in dairies where the main cleaning agent is caustic: The cleaning chemical contaminates itself with calcium-rich product residues during washes, which in turn reduces its effectiveness over time.
Another challenge is how to measure performance. Typical CIP sensors will be flowmeters (action), conductivity meters (concentration), and thermometers (temperature). The sensors will just report the current or planned situation (for example, run caustic at 1.2% and 30 m3/h for 20 minutes at 75 C [132 GPM and 167 F]). None of these sensors will report whether this time is ridiculously long or just barely sufficient. Let’s be clear—sensors are very important during production, but the installation of novel devices that use methods like spectrophotometry to accurately measure each step’s time of efficiency remain relatively infrequent. For this reason, any change done without introducing new technology will be very inefficient as it will require extensive visual checks, bacteriological tests, and a lengthy validation process.
As the benefit-risk ratio of implementing new technologies for CIP optimization is often perceived unfavorably, when it comes to solving hygiene or quality issues most companies will try in the beginning to extend washing time or raise chemical concentrations. However, most of the time these changes won’t solve the problem.
At the end, all this then translates to massive resources wasted globally every day, with a huge environmental and economic impact, without ensuring a better-quality performance. Hence, the best ways to achieve both quality improvement and savings is to increase the information available by adding specialized sensors, investing in data analysis, and adding novel technologies.
Technology-Supported Clean in Place Optimization
A relatively novel technology that can support a CIP optimization through several angles is software-guided power ultrasound. This technology involves plate waves, sound-guided in metal plates, or pipes (also called Lamb waves). Akin to a low-power micro-vibration, the ultrasonic waves act on the fact that the first connection between fouling and metal pipe is weak Van der Waals forces, and disrupt this first interaction, preventing fouling from sticking harder. If action is taken already at that point and nucleation points are prevented from forming, then metal surfaces can be kept clean for a very long time.
This power ultrasound technology is efficient on various types of fouling and its benefits are especially seen where CIP chemicals aren’t performing as expected or chemical use isn’t an option. Uses include:
- Burnt Foodstuff: Caramelized sugars or Maillard reaction residues are difficult for chemicals to remove. They need surfactant additives, and even with them, washing performance is often poor if the layer is thick. Ultrasound is able to crack this layer and help cleaning chemicals to act deeper and remove burnt residues.
- Thick Fat: Caustics are efficient on fat provided the layer remains relatively thin. In very fatty processes (like butter or meat processing), fat clogging of pipes is common. Ultrasound has a very strong emulsifying effect that removes fat blockages in a matter of minutes, or can even prevent fat from depositing.
- Thick Scale: Though minerals are often handled by complexing additives or by acid, some processes aren’t able to use them or require lengthy and costly rinses. Ultrasound cracks through loosely assembled crystals within seconds.
Software-guided power ultrasound will increase mechanical effect (the “A” of TACT), which in CIP is often the most critical performance parameter. This is done mostly thanks to cavitation.
Besides its use during CIP, software-guided power ultrasound can be used during most production runs to prevent fouling from forming in the most difficult places. It can also be used for sterilization steps. This technology allows for longer production runs and increases production capacity and savings as CIP is needed less often.