Product Handling and Transportation
To design ideal conveyors for every application, it is necessary to understand the nature of the product and how it slides, rolls and flies, as well as how to present product at each step in the process to optimize each machine’s performance. The art and science of designing conveyors incorporates the perfect combination of chutes, lanes, diverters, gates, geometry, speed and stroke in order to feed, collect, grade and distribute.
Belting designs and materials are key to ensuring the overall safety of food products. For example, regular sanitation uses harsh chemicals and high temperatures. A belt’s design features allow access to hard-to-reach areas where bacteria hides. In terms of material, only stainless-steel belting can withstand that treatment over time and come out clean.
Conveying Whole Potatoes
According to Key Technology, after being washed and mechanically size graded, whole potatoes are fed to a whole potato sorter (WPS) either before or after peeling, depending on the processor’s objectives. While every conveyor at this point in the line needs to feature rigid, heavy-duty structures to withstand the weight of whole potatoes for the throughput required, feeding a digital sorter requires extra consideration. To maximize the whole potato sorter’s performance, the cameras, laser scanners or hyperspectral sensors must get a good ‘look’ at each object so product defects and foreign material (FM) can be identified.
“It is also critical that the product trajectory between inspection and rejection is consistent and predictable so defects and FM can be accurately targeted and removed without ejecting good product. The success of these objectives is largely dependent on an infeed conveyor’s ability to separate and singulate the mass flow of potatoes into discrete objects and to stabilize them for presentation to the sorter at the ideal velocity. Well-designed vibratory conveyors with corrugated lanes help the WPS to optimize product quality and maximize yield,” explains Jim Ruff, Vice President, Process Systems & Integrated Solutions at Key Technology.
Conveying Potato Strips
Once potatoes have been cut into strips by water knives, a dewatering shaker is required. To remove as much water as possible, a vibratory conveyor’s speed and stroke is critical. A mesh bed allows water to pass through the conveyor for recirculation. A sliver sizer remover follows, removing slivers typically 2-3 mm and smaller from the line. This is generally followed by a length sizing grader to remove shorts that will be transferred to a co-product line.
Next, a system of conveyors with a series of diverters and gates distributes the product flow to match the capacity of downstream equipment, which is either a strip sorter or automatic defect removal (ADR) system, depending on the philosophy and line configuration adopted by the processor.
To read the entire article, please check out the Jan-Feb print issue of Potato Processing International here.