Drives and Controls January 2023

SUPPLY CHAINS TRAP £24BN OF GOODS We might have hoped that the supply chain issues resulting from the Covid pandemic would have eased by now – but, unfortunately, this is far from the case. A recent survey of UK manufacturers by Barclays Corporate Banking has revealed that goods with a total value of £23.6bn are currently awaiting completion because they have been held up by supply chain issues. The survey of 631 UK manufacturers with more than ten employees found that the vast majority (72%) are currently holding items in their warehouses that are awaiting rawmaterials, ingredients or components that have not been delivered by their suppliers. On average this“unfinished business”is worth more than £1m to each company impacted. Worst affected is the steel and metals sector with £9bn of incomplete goods – equivalent to 19% of the sector’s annual turnover. In the food and drinks industry there is a £3bn backlog, while £2.6bn of plastics products and £2bn of electronic goods are also awaiting completion. Some 59% of the manufacturers surveyed report that they are facing supply chain issues, which have been exacerbated by Brexit and the Ukraine war. To offset rising costs such as energy and transportation, 55% of those polled are planning to increase the prices they charge for their products – by an average of 37%. To tackle the supply chain issues, 39% of businesses say they are increasing their storage capacities, while 33% are“near shoring”– moving their supply sources closer to home. A similar proportion (32%) have“friend shored”– working with suppliers in countries with strong trading relationships with the UK. More than a third (37%) are now working with more suppliers. To help tide them over, 38% of the manufacturers are seeking cash injections from private equity, while 32% report they have been selling off assets to raise funds. On average, the manufacturers reckon that they will only be able to sustain their operations for a further 15 months if conditions do not improve. Despite this, most manufacturers remain optimistic with 66% of them expecting supply chain conditions to improve in the coming six months, and 86% predicting that they will grow this year. Many automation suppliers have had to redesign their products to use more readily available components. But there have also been reports of some machine-builders abandoning their traditional European suppliers for Far Eastern alternatives to ensure more reliable supplies. Will they return when the pressures ease? We have yet to see whether China’s recent relaxation of its Covid rules will improve supplies, but with the virus now reported to be running rampant, the prospects do not look good – in the short term at least. Eventually, global trade will return to a stable state, but it will probably look very different to the way it was before the pandemic. Tony Sacks, Editor n COMMENT Drives & Controls & n BACK TO BASICS SPONSORED BY Almost all food and beverage plants need cooling and refrigeration at some point in the process, whether for raw ingredients or finished products. George Dodwell, ABB area sales manager for drives, explains what to consider when installing VSDs for refrigeration applications. I ndustrial cooling and refrigeration systems can consume a lot of energy, not least because they often run continuously. Screw and reciprocating compressors also need high overload capabilities. A variable-speed drive (VSD) is a natural fit for these applications because drives can reduce energy usage significantly throughout their lifetime, allow better control over temperature to reflect needs at a given time, and reduce equipment wear. Here are three things to bear in mind when installing, replacing or upgrading drives for refrigeration applications: Understand the compressor’s overload requirements Depending on the type of compressor, overload requirements may be much higher than for other applications. Compressing air needs a lot of mechanical inertia, and thus a high starting current. This has implications for the kind of drive to use, because the overload requirement can be up to 160%. In some cases, this will require a heavy-duty drive. Many general-purpose drives (such as ABB’s ACS580) will have heavy- and normal- duty ratings, however you may still need to oversize your drive to handle both the application’s power requirement and the overload current. For example, an 11kW compressor application with 160% overload will require a drive rated at 30kW or more. Check mechanical infrastructure Before the advent of VSDs, cooling power was controlled using valves, louvres and dampers. A VSD can instead provide constant and precise pressure and flow control automatically, regardless of the conditions, and without the need for any mechanical vents or other devices. After a drive has been installed, these mechanical items are sometimes not only left in place, but left fully or partially open/closed. This is extremely inefficient, because everything a damper is stopping, and/or anything that is escaping through a vent, is simply wasted energy. After installing a drive, check the mechanical infrastructure and fully open/close, or remove, any unnecessary mechanical controls to allow the drive to operate with maximum efficiency. Use a trusted provider For the reasons outlined above, and many others, refrigeration is not like other applications. To achieve the best outcome for your facility, you need to work with a service provider, installer or OEM who has knowledge and experience of the F&B industry, as well as compressor drive requirements, where drives should be installed, and how they should be used. n Three rules for installing refrigerator compressors