Look behind the scenes
A food manufacturer used a multi screw pump to convey hot chilli and tomato sauce until 2015. However, this pump did not achieve the required flow rate and at the same time by shearing reduced the product quality. In order to avoid this problem in future and to ensure efficient production and smooth conveyance, the existing unit was re-placed by two NEMO® progressing cavity pumps from NETZSCH.
The first pump transports the medium into the heater at a temperature of 65°C and then the second pump conveys the medium at 98°C into the heat retention section, which is upstream of the heat exchanger (cooler). The progressing cavity pumps’ design and the way they work mean of unit conveys the medium in a way that is particularly gentle on the product. In contrast to the multi screw pump used previously, the progressing cavity pumps work at a low speed which does not affect the quality of the chilli and tomato sauce.
Both progressing cavity pumps were connected in series to achieve high conveying pressures overall and thus an efficient pumping process. This configuration was necessary because there are pressure losses of 35 to 40 bar due to the design of the pasteurisation system. “The heat exchanger and the heat retention section mean that pressure losses accumulate”, said Gozzer. “Spreading these across two pumps enables us to avoid exposing the product to mechanical stresses that are too high.” This means smooth handling of the sauces is ensured during pasteurisation. The NETZSCH progressing cavity pumps which are used have a CIP system. The elastomer materials are manufactured and comply the requirements with the FDA (Food and Drug Administration) and Regulation (EG) Nr. 1935/2004. Both NEMO® progressing cavity pumps have been successfully employed by the food manufacturer since July 2015 and have been running smoothly and quietly. They relia-ble achieve the desired flow rate, although the food manufacturer has been able to re-duce the energy consumption due to the technology change. Since then the manufac-turer has no longer been able to detect any damage to the product structure during con-veyance.