CIP preventing the risk of cross-contamination in bag filters

CIP preventing the risk of cross-contamination in bag filters

Globally, we see a growing demand for high quality and safe food products. To make the most of this opportunity, the dairy and food ingredients industries have to focus on high productivity while ensuring a low cost of ownership. At the same time, they also have to guarantee a high level of cleanliness – to uphold hygiene and sanitary standards and prevent cross contamination between productions.

The threat of product carry-over and cross-contamination

Fulfilling hygiene and sanitary standards for process equipment with CIP (cleaning in place) can be a challenge. Especially when you have a mix of different materials in the process equipment. E.g. the interface between filter bag fabric and stainless steel tube sheet to be identified as a critical control point (ccp) in a HACCP audit. This is where you risk cross-contamination or product carry-over. If you have a production line that makes fatty or high protein dairy or food products, for example, traces of fat or protein may be carried over when you switch to a production that does not contain these ingredients. Or you could have traces of critical enzymes or proteins from one product being carried over to another product or caffeine in decaffeinated coffee powder — which may cause an allergic reaction to some people. The risk of cross-contamination is not restricted to dairy and food ingredients, though. It is a challenge the pharma industry faces as well.

Clean air chamber CIP

Clean air chamber CIP with nozzles for internal bag CIP controlled by the indexing system.

Simatek’s Special Full CIP Wash

We’ve developed a solution to address this challenge. Unlike standard bag filter CIP that cleans the filter bags only from the outside, the CIP function of our bag filter and Special Full CIP Wash cleans the filters bags from both inside and outside (film above). It uses a unique CIP recipe and CIP nozzles that are designed to ensure complete CIP in all critical areas. These include the filter bags and the interface between the filter bag and the tube sheet (film below) connecting the clean air chamber and the powder side of the bag filter.


The cycling of CIP supply pressure to the CIP nozzle ensures effective CIP cleaning between the bag and the tube sheet, as well as along the length of the bag. When not in CIP the CIP nozzle is supplied with purge air to avoid condensation and product build up underneath the tube sheet.

Another challenge with CIP is that the filter bags are not sufficiently drained after CIP — this can result in product deposits being left at the bottom of the filter bags and an extended drying time. Simatek’s specially designed bag cages solve this problem by ensuring proper draining of the filter bag.

For powders containing allergens, the special CIP recipe contains an extra wash with special cleaning agents. One of these works to inactivate the allergen during cleaning; another sterilises the bag filter.

If filter bags are not cleaned both from inside and outside, they need to be replaced as a part of the cleaning of the bag filter. In addition to the cost of the new bags, this process increases downtime and cost of the CIP before the next production. The Simatek SimPulse 3C bag filter with internal bag CIP complies with the EHEDG and USDA standards and carries the 3-A certification (40-04), ensuring that your food powder production line meets the best practices in hygiene and sanitary standards.


The SimPulse bag filter series 3CX-CIP is 3-A symbol certified according to Sanitary Standards for Bag Collectors 40-04 and apply to the USDA guide lines as well.

The 3CX-CIP filter series comprises a complete range of filters up to air flow of 210,000 Am³/h (123,000 ACFM), each of which equipped with fully automatic CIP of the filter chamber and the clean air chamber as well as the filter bags.

The certification has been assigned in compliance with the Third Party Verification.
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The Simatek SimPulse 3C bag filter with internal bag CIP complies with the EHEDG and USDA standards and carries the 3-A certification (40-04), ensuring that your food powder production line meets the best practices in hygiene and sanitary standards.

Benefit from lower cost of ownership

The advantages of choosing the Simatek SimPulse 3C bag filter are not limited to preventing cross contamination through product carry over.

CIP nozzle animation

Animation shows full CIP coverage of all internal sources in the top section. The indexing of the pulse air pipes on which CIP nozzles for internal CIP are mounted, takes care of internal bag CIP.

When you opt for the Simatek SimPulse 3C bag filter, you benefit from lower energy consumption, higher uptime and longer bag life. This helps you save on bag replacement costs and reduces the downtime involved in changing the bags. Combined with the Special Full CIP Wash, it delivers a lower total cost of ownership.

If you would like to discuss how the Simatek SimPulse 3C bag filter and the Special Full CIP Wash can help you tackle the risk of cross contamination, please contact us for more information.

We have gathered some few questions regarding 3C CIP
What is special about the CIP-nozzles?

Simatek has two special developed CIP-nozzles for CIP of the bags (4B and 6B) which is the most critical part of the bag filter. The 4B and the 6B nozzle has the same function, to wet and clean the bags from the top and to clean the interface where the bags are mounted in the tube sheet. By pulsation of the CIP-liquid pressure the nozzle head moves out and in, and hereby adjust the shape of the CIP-liquid spray from down the bag to the top at the bead ring tightening the bag to the tube sheet. The nozzles are blockage free secured by a min. 3mm passage through the nozzle.

How does the CIP of the bags from the inside work?

The bags in the SimPulse 3C bag filter is cleaned at the inside by using special CIP nozzles situated on the Pulse Air Distributor in the clean air chamber. During CIP of the bag filter the CIP nozzles positioned over the filter bag opening are rotating step by step via the index system.

Is the CIP-liquid recirculate during CIP of the bags from the inside?

Yes and to avoid accumulation of powder solids in the bags, we use a fabric filter on the CIP line to filter out particles before the liquid enters the bags.

Are the CIP-nozzles EHEDG or 3A certified?

The Simatek 6B CIP-nozzle is holder of the USDA Equipment Acceptance Certificate and so made in compliance with the USDA GUIDELINES FOR THE SANITARY DESIGN AND FABRICATION OF DAIRY PROCESSING EQUIPMENT or applicable 3-A SANITARY STANDARDS. With this certification the CIP nozzle fulfills applicable EHEDG standards as well.

How can allergen carry over to next production be avoided?

The combination of the 4B or 6B CIP nozzle with the internal bag CIP Simatek ensures perfect cleaning of the critical areas of the bag filter such as the interface between filter bag and tube sheet preventing product carry over and cross contermination. Powder particles in the filter bag material or particles gone through the filter bag material, can be blown back through the bag material and into the bag house powder fraction of the next production – this can avoid by CIP of the filter bag inside. A special CIP program comprising an enzyme wash is typically used as well to ensure inactivation of allergens.

How long does the CIP of the bag filter take?

Typically, CIP of the bag filter takes 13 to 20 hours including drying, depending on design and capacity of the CIP system, powder characteristics and chemicals used.