Bottle washers are one of the most cost-intensive pieces of equipment in a line, and so their resistance to malfunctions and their efficiency are vital considerations for plant managers.
A line processing 60,000 bottles an hour, with 1 g of dirt per bottle will produce 60 kg an hour, which with a weekly constant running time of 150 hours adds up to nine tonnes.
Krones, based in Germany, has developed a new pre-soak concept, which the company says can clean a high volume of returnable bottles.
The debris can consist of sand, beverage residues, crowns, cigarette ends, glass fragments and bits of dress.
Mechanical systems, such as sieving-conveyor removal systems or rotating cullet scrapers, are susceptible to malfunctions and are difficult to clean and maintain, claims Krones.
Krones' pre-soak system uses hydraulics to operate a propeller pump with a recirculation rating of about 500 cubic meters per hour ensures a flow across the machine. Krones claims this system is more efficient and reliable than competing products.
The recirculated flow is taken from the filtered side of a small label removal unit, pumped through a pipe extending over the width of the machine, and then fed back into the machine again. This flow energy is sufficient to convey all the dirt and dress residues through the pre-soak channel into the sieve case, the company claims.
In the specially shaped lower section of the sieve case, the heavier parts, like glass or sand, settle to the bottom under gravitational force. The lighter substances, like label paper, are carried along on the surface and taken out of the machine on the sieving conveyor removal unit.
The glass fragment collecting tank is connected to a removal lock with a vertical pipe. The valves are controlled and the lock emptied in dependence on the amount of glass fragments collected.
The flow channel in the bottom pre-soak segment. The high turbulence of the flow gives the dirt involved no opportunity to collect, claims Krones.