Features
- Reduction of energy consumption
- Reduction of waste water
- Low maintenance
-
Hygienic design, food safety
General Process Description
From the storage the raw product is brought into the cyclone de-stoner by means of a belt conveyor. The water carries the potatoes into the washing drum, where an (adjustable) layer of potatoes is present, creating thus intensive rubbing of the individual potatoes. The washing process is enhanced by overhead sprays in the drum.
A screw conveyer subsequently transports the potatoes to the weighing hopper, that doses a pre�set amount of potatoes into the steam vessel. Steam pressure is built-up in the vessel and held during a pre-set time, while a rotating arm stirs the potatoes. Thereafter the steam is relieved very fast into the expansion vessel. As a result the skin explodes off the potatoes. The batch is emptied into the extraction screw, transporting the potatoes to the dry peel remover. In the counter-flow screw washer the remaining peels, sand and other foreign objects are washed off.
The specifications of the final product determine whether the potatoes are sliced or processed as whole. Sliced potatoes pass the vibrating screen washer. Removed free starch is collected in a concentration pocket and is evacuated continuously for further treatment in a starch recovery system. The sliced or whole potatoes are generally delivered to the blancher.
From the slicing unit and vibrating screen washer, the potatoes are fed into the blancher and subsequently to the cooler, or bypass this via the flume system to the even flow screw conveyor. In the cooler the product is cooled in a counter current flow with water.
The potatoes are dosed in a cooker. Condensate is removed continuously. At the end of the cooking section the potato mash drops in screw conveyors for delivery in the powder back-mixer. Additives are mixed in the additive station and pumped to the inlet of the back-mixer.
The cooked potatoes drop into a ricer. In the ricer the potatoes are mashed and either fed into the feed hopper or into a screw conveyor. In the bottom part of the feed hopper a small screw brings the potato mash to the product pump, which in turn transports the potato mash to the center of the trough of the feed screw located on the drying drum of the potato flake dryer. Potato mash that is fed into a screw conveyor is transported to the center of the trough of the feed screw located on the drying drum of the potato flake dryer.
The screw evenly distributes the product for the first applicator roll over the full length of the drying drum.
Product passing between the applicator roll and drying drum, will be precipitated on the drying drum. After passing the last applicator roll, the final film thickness has been achieved.
On the last applicator roll peel waste will be collected and scraped off periodically by a transfer scraper. The waste drops into the waste conveyor and is subsequently discharged.
During its residence time on the dryer the water evaporates and the dry solid in the puree increases in the area from the feed point to the last applicator roll. Next, the remaining water in the product layer on the drum surface evaporates until, after an almost complete turn of the drum, the film layer is scraped off by the knife and the product has reached its required final residual moisture content.
The evaporated water is evacuated via the vapor hood above the dryer and the vapor extraction system underneath the drying drum using in total four vapor fans. The vapors are evacuated through a chimney.
The scraped off product film falls into the side screw conveyor and is then pre-crushed and transported to the inclined screw conveyor or into a pneumatic transport system.
The product film fragments are transported to the Mill Sifter to ground to flakes of the required size. The flakes leave the Mill Sifter through the funnel shaped hopper underneath.
