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‘Spiroflow’ Big Bag Dischargers – smashing!

Posted on 10th January 2008 by

We are delighted that brand leader Premier Foods have recently purchased 2 of our Big Bag Dischargers and 4 of our Flexible Screw Conveyors to deliver processed product to packing lines at their Histon site. The product in question is SMASH Instant Mashed Potato. As Premier Foods’ 1970’s ‘Martians’ advertisement has been voted the best TV ad of all time, SMASH ranks among the UK’s best known consumer brands.

Premier Foods operate 7 production sites in the UK and employ over 3,000 people. Their Histon site has been in existence for over 100 years with a complement of around 350 employees. It is also the home of Hartley’s jam, Rose’s marmalade and Chivers Jelly.

It was a change in the SMASH production and handling methods that brought about the need for the new Big Bag Dischargers and Flexible Screw Conveying system. Previously, product made on site at Histon was held in storage hoppers and then transferred from the production area to the packing hall via an overhead conveyor belt system feeding each of the 4 main packing lines. Processed product is now filled into and stored in 2m3 big bags. These are brought to the packing hall by forklift truck at the rate of 16 a day. In the packing hall, these big bags need to be discharged in an efficient and dust tight manner. The forklift truck removes empty bags and places full bags into position on the ‘Spiroflow’ Dischargers using the Big Bag Lifting/Support Frames supplied with the dischargers.

When lifted into place, the bags sit in the discharger on an annular flexible membrane, this forms a dust-tight seal around the base of the bag. By way of access doors in the dust-tight cabinet below the membrane, the neck of each bag is pulled down through the aperture in the membrane and stretched over an upstanding spigot. The bag spout is held in place by a large o-ring band. This spigot is the inlet to the collection hopper below each Discharger. With the cabinet doors closed, for safety reasons, pneumatic spout closure bars pinch the bag spout above the point at which it is tied. With the interlocked doors open again, operators are able to untie the bulk bag spouts. Once the spouts are untied, the cabinet doors are closed again, the spout closure bars are opened and product then flows into the collection hoppers below.

As product is discharged, and the big bags become ever lighter: springs within the big bag support arms, on each side of the Dischargers, raise the bags higher and higher to keep them taught and to ensure maximum discharge of the contents.

An alarm indicates when the bags are empty. The removal of the bags is a simple procedure during which they can be tied off to prevent any residual dust escaping during lifting from the Dischargers.

Each of the collection hoppers below the 2 Dishargers has bifurcated outlets from which 2 ‘Spiroflow’ Flexible Screw Conveyors from each of the 2 Dischargers deliver product to the 4 packing lines. These conveyors are controlled by ‘low’ and ‘high’ level probes in the buffer hoppers above each of the filling machines. The Flexible Screw Conveyors range in length from 8 to 10 metres and operate at a variety of angles. There is a fifth, pre-existing, ‘Spiroflow’ Flexible Screw Conveyor that is used to return perfectly good product to one of the packing machines after it has been recovered from any ‘out of spec.’ packaging. It was this existing conveyor and other ‘Spiroflow’ equipment on site that encouraged Engineering Manager, Kevin Murray, and his colleagues to choose Spiroflow as the supplier for their new SMASH handling system.

Although Premier Foods already use ‘Spiroflow’ Flexible Screw Conveyors on sugar at Histon, given that the Smash application was new, tests were carried out our comprehensive test facility to determine the optimum specification for the Dischargers and also the correct type of spiral for the conveyors. The controllers for the Dischargers and Conveyors were designed and manufactured by us ‘in-house’. The installation and commissioning was carried out by our engineers.

The equipment has been in operation for 10 hours a day for over 6 months now and Kevin Murray reports that the equipment has performed to his satisfaction. Since installation, Premier foods have benefited from improvements to product quality and they have also seen reductions in both labour and utility costs.