Automate CIP, track pipe status
O h how much easier the manufacturing of pharmaceuticals, nutritional, and beverage products would be if the vessels, equipment, and pipes used in processing the product could be disassembled, dropped in a sink, vigorously scrubbed and then run through a sterilizer to remove contaminants. In reality it's impractical to use cleaning techniques commonly found in laboratories and kitchens in large-scale production facilities. Vessels, equipment, and pipes must be cleaned where installed. The clean in place (CIP) process ensures that piping, vessels, and equipment are free of inorganic and organic contaminants. For processes where microbiological cleanliness is essential, CIP also encompasses steam in place (SIP) procedures.
What to look for in a CIP `aware' control system
A utomating CIP procedures requires the control system provide capabilities to ensure:
Many production facilities do CIP manually, but history repeatedly indicates manual cleaning can be unsafe and the level of cleaning is typically much less effective and less consistent than fully automated CIP procedures provide. But what's eye opening to first timers is that automating CIP procedures is often more complex and requires greater efforts in design, testing, and validation than for automating 'real' products.
How hard can it be?
For those who have never automated a CIP process, it seems simple and straightforward. After a vessel is drained of a product, all that's required is to rinse, clean, wash, and do a final rinse-how hard is that?
Not too hard if all that were required was to ensure cleaning and washing mixtures were correctly formulated and proper flows, temperatures, and pressures were maintained for one product or product family. But production facilities designed and hard-piped to produce a single product or family of products, are giving way to flexible facilities capable of producing multiple products and maximizing the use of vessels and equipment.
Key to achieving near maximum flexibility and asset utilization is the ability to move contents of one vessel to any other vessel with minimum effort. This requires replacing 'hard-piping' with any one of several flexible transfer-piping methods, adding to the complexity of CIP automation. For example, vessel, transfer piping, and equipment path integrity must be maintained until cleaned, and each piece of equipment must be individually tracked for dirty, cleaning, clean, and cleaned but expired status.
Cleaned but expired?
Given time, some contaminants can reappear, so a vessel, pipe segment, or piece of equipment may require recleaning before being used to produce a product, thus the need for the cleaned but expired status.
In developing a product's control logic, it's important to 'acquire' each piece of equipment as a prerequisite for introducing material. Usually vessels and pipe segments are exclusive use; meaning only one operational sequence can acquire the element at a time. Equipment, such as transfer pumps, are often available for shared use, meaning they can be acquired and used by more than one operational sequence as long as the materials passing through the shared resource are compatible.
When evaluating the next control system, be sure to investigate the system's ability to handle CIP (See sidebar). In the long run, it may be less effort to automate CIP than to ensure manual CIP activities provide contamination-free vessels, equipment, and piping segments.
Dave Harrold, senior editor