April 2020

38 n FOOD AND BEVERAGE April 2020 www.drivesncontrols.com C ompact, efficient geared motors are used on many food processing lines. They are ideal for driving stirrers, agitators and conveyors. However, while standard designs are suitable for many applications, strict hygiene regulations mean that for some duties, more specialised motors are preferable. The Hazard Analysis and Critical Control Point (HACCP) system is an internationally recognised method for reducing risk factors in the production or processing of food. It requires manufacturers to evaluate all processes in their production lines continuously to identify possible hazards and to minimise risk at critical points. The aim is to protect people from food-borne illness, although it is also recognised as a best practice approach to improving quality and consistency in the final product. Understanding the process of analysing risks on production lines and making improvements helps to explain the evolution in the industry’s preferred choice of geared motor technologies. In the past, geared motors were always used because of their efficiency and reliability. However, as hygiene regulations became tighter, it was became necessary to source specialist drives for food and beverage applications. Aseptic drives were developed for applications where washdowns are needed to maintain a clean environment. These drives are typically painted using acid- and alkali- resistant coatings, which can withstand chemicals with a pH of 2–12. As a result, they can withstand the cleansing solutions and disinfectants commonly used in the food industry without affecting their performance. Aseptic drives deliver all of the performance benefits of a standard geared motor, while eliminating some of the hygiene risks. However, with a HACCP system in place, a further risk assessment may identify that the coatings on these drives are prone to damage. This would expose the motor’s surface to corrosive chemicals and risk the food product being contaminated with paint fragments, even if the coating is FDA-approved. Therefore, many in the industry are now specifying stainless-steel motors instead. Stainless-steel geared motors meet all of the regulations set out by organisations such as the FDA and NSF, without needing specialised coatings. As a base material, stainless-steel is inherently resistant to corrosion and chemicals, ensuring that repeated washdowns do not affect the reliability or hygienic qualities of the geared motor. Furthermore, if stainless steel is scratched, it does not compromise the motor’s corrosion or contamination resistance. Stainless-steel geared motors – such as Bauer Gear Motor’s HiflexDrive – are designed so that fans and cooling ribs are not needed, resulting in a smooth outer casing and a sealed non-drive end. This allows the motors to offer protection up to IP69k – protecting them against high-pressure washers and steam cleaning. Eliminating venting elements creates a smooth outer surface, making it easier to clean the motor and preventing the re-infection of the local environment caused by air movement from a cooling fan. Take for example, the German dairy, Rücker, which processes 2.2 million kg of milk at its two factories each day. Every year, it produces 80,000 tonnes of cheese, 20,000 tonnes of milk powder and 20,000 tonnes of butter. Reducing HACCP risk factors is essential on Rücker’s production lines. It has moved from standard geared motors, through aseptic models, and now uses stainless machines. At one of its sites, Rücker uses a 60m-long coagulator to process cheese curd. The machine has several stirrers that keep the milk moving as the whey is removed. Each stirrer moves along a section of a lane. Once it reaches the end, it is lifted out of the curd and moves back to the starting point. Rücker’s engineers realised that integrating brakes into the housings of its geared motors would increase their cleanability and thus reduce risk. It upgraded its geared motors to aseptic drives to take advantage of their improved hygiene ratings. Now the first of the aseptic drives have, in turn, been replaced by stainless steel drives with integrated brakes, offering added hygiene performance and mechanical resilience. n Yasar Yüce, product manager at Bauer Gear Motor, explains the growing popularity of stainless-steel geared motors in the food and beverage industry. Rücker’s 60m-long cheese curd coagulator machine has several stirrers that keep the milk moving as the whey is removed. Stainless-steel geared motors comply with regulations set out by organisations such as the FDA and NSF without needing specialised coatings. Reflecting on the benefits of stainless motors