Food purity: the fluid spaces of the pumps are free from 26 critical substance groups
"The wrong nutrition and malnutrition can have a very rapid and long-term impact on health, especially in the case of young children," said Rainer Sonnenfroh, a sales engineer at LEWA GmbH." For this reason, the production systems in this sensitive food sector must meet particularly stringent specifications, which often makes special designs necessary." This also applies to the new filling line for baby food with fish oil metering, for which LEWA supplied the pump technology. In order to ensure perfect food purity, a total of 26 substance groups must be excluded from the metering pumps used: they must not come into contact with the baby food during production under any circumstances. The substance groups include phthalate plasticizers, organotin and halogen-containing compounds, heavy metals, flame retardants, bisphenols, formaldehydes, melamines and microplastics.
In addition, the new line fills a range of food products for babies. Depending on whether the product contains vegetables, meat or fish, for example, the fish oil added to the baby food must be dosed higher or lower due to its high levels of omega-3 fatty acids. Therefore, the pump must ensure a very high metering accuracy of +/- 0.5 percent over the entire speed range. The sum of these requirements made it difficult to find a pump manufacturer able and willing to supply suitably compliant units. When the plant construction company finally sent an inquiry to LEWA, the Leonberg-based pump specialist, at the end of March 2021, the order was already classified as time-critical.
LEWA ecodos diaphragm metering pumps with wide-range speed control for sensitive food production
"Our ecodos sanitary/hygienic diaphragm metering pumps are predestined for sensitive food production in the low-pressure range," explained Sonnenfroh." They are made of hygienic stainless steel and have both FDA-compliant Gylon seals and PTFE sandwich diaphragms, so they already meet all the baby food manufacturer's specifications regarding substance bans as standard." In addition, for food production – and especially for such critical product groups as baby food – it is essential that the metering pumps used are easy to clean and also have robust, reliable technology for continuous operation. Therefore, ecodos sanitary/hygienic diaphragm metering pumps have only minimal dead space and even when installed, are CIP and SIP capable. The fluid valves of the pumps are the main wear parts. They achieve a service life of more than twelve months, while the four-layer PTFE sandwich diaphragms are designed for a service life of approximately 24 months.
The second challenge that the pumps of the new filling line had to master was high metering accuracy of +/- 0.5 percent across the entire control range. "For this purpose, we put the new technical concept for wide-range speed control of ecodos metering pumps into practice," said Sonnenfroh. The NORD drives 71N1/8 with 0.35 kW and 71N2/8 with 0.7 kW are controllable with high precision, and can maintain a constant torque curve even in the lower speed range. Wide-range speed control with permanent magnet synchronous motor (PMSM) also offered the plant construction company the possibility to implement previously tested and approved frequency inverters from DANFOSS for control. "To be able to realize the delivery in the very tight time frame required, we relied on only two model types from the very beginning, namely LEC1 for the lower flow rate and LEE1 for the higher one," Sonnenfroh continued.
LEWA proves itself as a customized solution provider
LEWA delivered the six type LEC1 ecodos pumps and the four type LEE1 models – including all the necessary certificates of conformity with regard to banned substances – within a few months: by August 2021. The baby food producer was able to commission the completed filling line on schedule in November of the same year. "The project shows that we can implement customized solutions even at relatively short notice," said Sonnenfroh in summary. "With our ecodos Sanitary/Hygienic diaphragm metering pumps and the PMSM wide-range speed control as standard, we already cover the sensitive food sector and the rigorous requirements for metering accuracy, as they prevail in baby food production and fish oil metering."
