It has long been recognized that the cleaning and/or peeling of fruits and vegetables (produce) at a high rate with minimal waste and handling damage is important in the food processing industries. Attempts to accomplish this have presented difficult problems due to many factors, including the highly irregular surfaces of certain produce, such as potatoes, the substantial variation in optimum abrasive surface pressure, the susceptibility of some produce to handling damage, differences in epidermis characteristics of different produce types and different species of the same type, the ever increasing difficulties in disposing of waste wash water and treating chemicals and the recent substantial increase in the cost of energy for producing steam, hot water or radiant heat for certain related operations.
High capacity produce peeling and cleaning devices have been utilized for many years, as exemplified in U.S. Pat. Nos. 3,134,413; 3,566,942 and 3,946,658. Such devices relied upon gravitational tumbling of produce groups in a generally horizontally oriented, rotating, peeling cage constructed of rotating abrasive spindles, with a revolving auger therein for moving the tumbling groups therealong. A new concept was presented in U.S. Pat. Nos. 4,062,985 and 4,068,574 wherein the peeling cage accelerated the produce to a rotary speed sufficient for maintaining the produce in continuous centrifugal force contact against the spindle abrading surfaces. This greatly improved the potential cleaning and/or peeling efficiency by presenting a many fold increase in functioning abrasive surface area within the cage, while also permitting highly accurate control of produce pressure thereagainst by merely varying the cage speed. Further, the new arrangement reduced the likelihood of produce damage by substantially decreasing tumbling.
Although the improved method and apparatus disclosed in said U.S. Pat. Nos. 4,062,985 and 4,068,574 constituted a marked improvement over prior art devices, some difficulty was experienced in accurately controlling the residence time of the produce within the treating cage. It was also recognized that certain variations in the abrasive surface of the cage spindles were desirable for optimum utilization of the new produce treating arrangement.