What is the CIP Cleaning System

In industries, CIP cleaning is one of the most widely used procedures to provide fast, safe, and efficient environmental sanitation. Learn more about the importance of proper CIP cleaning and the particularities of this type of sanitation.

Keeping an industrial plant clean is essential to ensure the quality of what is produced and prevent the presence of microorganisms that could harm production and consumer health. For this to happen, this cleaning must be complete and thorough. In industries, CIP cleaning is one of the most commonly employed procedures, as it minimizes potential human errors in the procedure, ensuring efficiency in system sanitation. Moreover, it is considered an environmentally sustainable procedure, as it is possible to reuse the chemical products applied in the procedure when you have a CIP central unit. Below are some advantages of the CIP system, its importance, and the particularities of this type of sanitation.

What is the CIP System

The CIP method or Cleaning in Place is the name given to the industrial sanitation process, using the passage or circulation of cleaning products without prior disassembly of equipment. In this procedure, all contact surfaces are cleaned, achieving a high standard of sanitation. This type of cleaning is a reality in any automated or semi-automated plant and aims to remove dirt that causes stains, generates odors, and product contamination.

Advantages of the CIP System

• Reduces environmental impact and operating costs
• No equipment disassembly required
• Reproducible results
• Ensures the highest levels of food safety
• Guarantees precision in liquid control
• Uses predefined cleaning programs
• Preserves operational safety
• Most viable method for large tanks, piping, heat exchangers, and concentrators
• Optimizes time and production availability

Stages of the CIP Cleaning Process

However, for CIP cleaning to achieve the expected results, the procedure itself must be done correctly. Nevertheless, the cleaning process may vary according to the processing plant (food, beverages, and dairy, for example). Generally, CIP cleaning includes the following stages:

• Pre-wash with water to remove gross dirt
• Plant wash with an alkaline detergent or acid detergent
• Intermediate rinses to remove detergent residues
• Application of disinfectant for microbiological control
• Final rinse

It is important to highlight some particularities in each of these stages:

• Pre-rinse: The purpose of using the pre-rinse is to remove gross dirt. It is recommended to use temperatures between 40 to 45°C to avoid food solidification.

• Alkaline cleaning: The alkaline detergent circulates throughout the entire system at the predetermined concentration (generally 2% in food industries) and the recommended temperature is up to 80°C, to saponify fats and dissolve proteins.

• Intermediate and final rinses: Water passes through the system at temperatures up to 40°C. This rinse has the purpose of extracting most of the residual product from the alkaline or acid cleaning stage. Detergent residues can reduce the effect of the acid agent from neutralization reactions of the products (acid/base reactions).

• Acid cleaning: Must be done with hot water, between 60 to 65°C with the application of acid detergent. Acid cleaning is done to remove possible mineral residues. The physical-chemical and microbiological quality of water must be guaranteed, especially for disinfection and final rinse.

• Disinfection: Must be done shortly before production restart, on the same day or the following day, or repeated after an overnight shutdown. This phase requires water circulating through the system at ambient temperature and aims to ensure microbiological control of surfaces for upcoming production runs.

• Final wash: The final rinse, properly speaking, consists of passing water through equipment and piping with water circulation within quality standards.

Sanitation can be done shortly before production restart, on the same day or the following day. It is important to mention that, for good cleaning, planning is essential. Considering this aspect, the Sinner's circle helps to quickly and simply elucidate the factors involved in achieving high levels of cleaning efficiency. In general, the four elements of Sinner's circle can be visualized in the figure below:

Chemical action, mechanical action, temperature, and time must be present in the process. If any of these elements needs to be reduced, another or others must be increased to compensate the circle and maintain efficient cleaning.

Performance of Cleaning Agents

Detergents are used as cleaning agents in the CIP process. The most commonly used for this purpose are alkaline, acid, and enzymatic. Alkaline detergents generally contain sodium hydroxide and are normally used at concentrations of 0.5% to 4%. This type of solution is very efficient for removing fats and proteins, as well as other organic compounds. Additionally, depending on the need, acid detergents can also be used, usually at concentrations of 0.5% to 2%. Acid detergents - containing phosphoric acid and nitric acid, for example - are applied in removing inorganic scale, at lower temperatures than alkaline detergents. They must be used with great caution to avoid affecting valves and pump seals, as they can cause corrosion.

Advantages of using alkaline and acid detergents:

It is important to consider that, regardless of the detergent used, it is essential that they present good effectiveness for dirt removal, in addition to not forming foam. Furthermore, one of the main requirements for using these detergents is that they do not cause corrosion, thus avoiding wear and possible ruptures of equipment or piping.

Use of Disinfectants in the CIP System

Although the use of detergents provides a reduction in antimicrobial contamination levels, in most cases the use of disinfectants is recommended for more efficient cleaning, meeting the requirements of current legislation and regulatory bodies.

During the application of disinfectants, the application temperature must be controlled throughout the entire process time. The disinfection time will depend on the active substance and the adjuvants in the formulation. To achieve this objective, some disinfectants containing hypochlorite, chlorine dioxide, quaternary ammonium, hydrogen peroxide, and peracetic acid can be used.

The conventional CIP process in food processing factories can involve many cycles. Some elements can still be cleaned daily with "short" cycles, only with alkaline product, and once a week apply the complete cycle. However, any recommendation about these processes requires the knowledge and analysis of a technician. Our specialists are ready to assist with the most appropriate sanitation programs for the reality of each manufacturing plant.

In industrial plants, sanitary control, technologies, and efficient products are part of the package of actions in combating contamination. Check out some important challenges of sanitation processes in the food industry.