The inside of a commercial fryer is an incredibly hostile environment for machine components. Bearings, for example, are subject to regular splashing by extremely hot oil for long periods of time, which can eventually cause sealing material to break down and allow contaminants to enter the arrangement’s inner envelope as well as the food-production area. There is also the issue of the cleaning operation: Every week or so, fryers must be drained and undergo a boil-out procedure with caustic-based fluids, during which some lubricant is inadvertently washed away, potentially into the food-processing area. This necessitates time-consuming relubrication with high-cost, high-temperature lubricants after each cleaning.

Bearing the burden

Even if bearings are cared for in this way, the severe operating conditions of fryers limit bearing service life to around 3,000 operating hours – or a service life of around three to six months. During this time, it is imperative that the condition of bearings and seals is monitored closely, as failure can lead to catastrophic outcomes. A fryer containing hot oil cannot just be switched off and repaired. Unplanned maintenance takes the equipment out of service for at least 24 hours and negatively impacts productivity. Operators and engineers have to take responsibility to ensure sealing and bearing integrity.

If a bearing becomes damaged it can leak lubricating grease, and pieces of the bearing itself can spill out into the fryer. With a failure of this type the oil must be drained and then strained and possibly even replaced to recover any wayward material. There is also the issue of contamination of the product. Food recalls and standards are on the rise, and any incident like this could render a product unfit for the market. The company suffers in terms of not only money and productivity but also reputation.

Cooking up a solution

To help food and beverage stakeholders – specifically operators of commercial fryers – combat these challenges, SKF engineers have developed a unique solution that facilitates a symbiotic relationship between the fryer and the bearing itself.

SKF’s team of experts concluded that fryer bearings’ load and speed requirements were low enough that the cooking oil itself could provide the necessary lubrication, so they set about developing a bearing with characteristics that allowed reliable operation despite the extreme temperatures and aggressive chemicals found in the customer’s equipment. The solution was a high-temperature plastic cage, specially designed to perform well in poorly lubricated environments with stainless steel rings and rolling elements.

The innovative SKF fryer bearings required no relubrication and met materials requirements for food and beverage manufacturing in corrosive environments. As a result, the snack food producer can use the same bearing for up to 17,500 hours – significantly increasing the existing bearing’s lifespan and eradicating unplanned stoppages.