TOUGHEST SHELL IN THE SHELLFISH LINE
Krijn Verwijs is one of Europe’s foremost suppliers of shellfish products including oysters, lobster and in particular fresh blue or common mussels. In its Yerseke – Netherlands based shellfish production centre, rapid drive corrosion due to the seawaterinfused atmosphere has long been a major concern. NORDaluminium geared motors with a special surface conversion treatment now provides an economical solution to resolve this issueFresh catches arriving at the factory are transferred into large holding basins with a constant flow of clean salt water to keep the product in good condition and thoroughly rinse off sand and debris. Given the close proximity of these containers and the fact that live mussels are then conveyed wet, all processing lines throughout the factory are inevitably exposed to a humid, salty atmosphere. These conditions spell swift corrosion for all sorts of unprotected metal parts used across the process automation equipment, for example in the numerous conveyor lines. For conventional cast iron geared motors, rusty spots first appear on brand new systems in a matter of weeks, and end of working life draws near for such units after only a year or two. Special coatings or varnishes merely help only to moderately delay the onset of corrosion. Stainless steel drives have never qualified as a solution since they proved not only very costly but impractical due to their requisite disruptive cool-off periods before every hose-down.
RESILIENT, AFFORDABLE, EASY TO CLEAN
Frequent drive replacements therefore used to be the order of the day at Krijn Verwijs until the company learned of a new design approach for drives deployed in aggressive environments: NORD DRIVESYSTEMS’ ‘CLEAN DRIVE’ nsd tupH surface treatment. This technology enables aluminium geared motors – which can be very easily and effortlessly washed down – to achieve stainless steel grade resistance to corrosion.
Krijn Verwijs has begun to roll out CLEAN DRIVE nsd tupH systems that are sure to provide considerable longer service lives in the salt-rich atmosphere. Though these aluminium geared motors do come at a premium compared to the price of conventional cast iron units, both lab trials and extensive real-life testing in the factory in Yerseke indicate that nsd tupH systems will last for the better part of the typical 10-year lifetime of a conveyor line, or even outlast the line altogether. Krijn Verwijs will therefore no longer have to purchase five to ten replacement drives for every unit, nor bother with the expense and effort for associated maintenance work.
PHYSICALLY INGRAINED PROTECTION
NORD’s nsd tupH treatment is not the application of a coating, but rather a surface conversion that produces a base layer that is permanently bonded to the substrate. Based on an electrolytic process, this treatment renders aluminium cases resilient and similarly unsusceptible to corrosion as stainless steel. The scratch resistant surface also becomes more than six times as hard as untreated alloy, and a thousand times as hard as paint.
SMART ALTERNATIVE TO STAINLESS STEEL
Featuring a very lightweight, compact, and self-draining design, CLEAN DRIVE nsd tupH systems for the food industry can be easily washed down. They are impervious to common chemical cleaning agents – neither rinsing them with acids or alkaline solutions nor applying highpressure cleaners will cause damage. In addition, the nsd tupH surface treatment is universally available for all NORD aluminium gear unit and motor products – unlike many stainless steel geared motor ranges which most manufacturers limit to a few types. The salty atmosphere everywhere in the Krijn Verwijs Yerseke production centre makes this seafood factory a textbook case for adverse environmental conditions – several hundred 1.5 kW class geared motors in various conveyor lines have long suffered from rapid corrosion. A full transition to resilient CLEAN DRIVE nsd tupH systems is now underway: in the months and years to come, every drive at Krijn Verwijs will eventually be replaced by an extradurable NORD geared motor. Bram de Visser of Krijn Verwijs technical service, comments: “This new NORD solution means we no longer have to worry about drives all the time. We expect nsd tupH systems to last at least five times as long as the old geared motors.”