November/December 2020

42 n CONTROLGEAR AND ENCLOSURES November/December 2020 www.drivesncontrols.com Get into the zone Food and beverage plants can be broken down into areas with differing hygienic requirements. Emma Ryde, Rittal’s product manager for industrial and outdoor enclosures, explains the three main zones and the types of enclosure needed in each of them. M aiintaining high standards of hygiene is a priority in all food and beverage factories. This means keeping machines, enclosures and systems spotlessly clean, while maintaining production efficiency. Within food and beverage production and processing plants, there are three categories of hygiene“zones”– high, medium and low. Choosing suitable enclosures to use in such plants depends on the zone where they will be installed. Zone 1: Food zone (high hygiene) The food preparation zone is the most critical area in a food plant. Due to the high risk of contamination, it is essential that the enclosures in this area are designed according to strict hygiene rules. Hygienic design guidelines state that materials must, among other things, be corrosion-resistant and easy to clean, while all joints must be sealed, seamlessly welded or glued. Unfortunately, many electrical enclosures fail to meet these requirements, and this can lead to water entering control enclosures during washdown and sanitation procedures. Water ingress affecting electrical components can cause considerable damage, leading to unnecessary maintenance and repair costs as well as production downtime. Hygienic-design enclosures have become the standard for electrical controls in food zones because they allow rapid cleaning, create a sealed environment for electrical systems, and prevent the formation of pockets of dirt. Zone 2: Spray zone (medium hygiene) The risk of contamination in this zone is lower than in the food preparation zone. Here, the food is already packaged or is undergoing further sterilisation treatments. So, for example, products such as milk are enclosed in pipe systems and are thus protected from the outside environment. However, floors are cleaned with chemical agents so any enclosures in this area should resist both corrosion and airborne chemical particles from the cleaning products. Stainless-steel enclosures are ideal for use in these areas. Cabinets constructed from this type of steel have long lives because they are resistant to water vapour, humidity and weak acids. It is essential to provide adequate climate control for the equipment housed in the cabinets. Design flaws in air-conditioning systems, or high ambient temperatures, can cause components to overheat, resulting in costly repairs and loss of revenue. Using thermal design techniques, these risks can be detected and remedied during the design phase. Climate control systems (also made of stainless steel) can be used to manage the temperatures within an enclosure, thus reducing energy consumption and extending the lives of electrical components. Zone 3: Non-food zone (basic hygiene) In low hygiene zones – for example, in IT areas or offices – the risk of contamination of food and beverage products is minimal. Enclosures in these areas do not need to comply with specific hygiene rules. The ever-increasing amount of data gathered from processing equipment, diagnostic systems and IoT devices means there is a rising demand to locate high-speed data processing as close to the source as possible. Edge data centres can handle a wide variety of such tasks, and can help perform critical processes, such as data capture and production monitoring, while providing scalability and resilience. If there is any risk to an edge data centre’s internal electrical components, enclosures can be tailored to specific industrial applications. For example, on a busy shop floor, the enclosure may need to have a high IP rating to avoid dust particles fouling the system. n Food and beverage plants can be broken down into a series of zones with different enclosure requirements in each