Delaere big bag filling line for FGR and boiler ashes mixture
Delaere big bag filling line for FGR and boiler ashes mixture
Delaere supplied a bigbag filling line to a large recycling plant in Ireland. The bigbag filling line is used to pack a mixture of Flue Gas Residue (FGR) and boiler ashes.
The bigbag filling line is equipped with 2 buffer hoppers, one for each product, which are connected to existing screw conveyors. These 2 buffer hoppers are positioned on loadcells to have exact knowledge of the amount of product inside the hoppers at all time.
On the outlet of the buffer hoppers, 2 dosing screw conveyors are installed which are connected to a Y-piece guiding the mixture of FGR and boiler ashes to the bigbag filling station.
Delaere installed an EV2SR bigbag filling station with height adjustable roller conveyor to enable filling of different types of bigbags. The filling station is equipped with a rotating filling head creating torsion on the filling spout after reaching the set weight in the bigbag. This rotating filling head is significantly reducing the labor effort of the operator to close the bigbag.
The semi-automatic bigbag filling line is equipped with a pallet dispenser and a number of roller conveyors installed behind the filling station to buffer filled bigbags on the line.
Challenge
A first major challenge in the design were the constraints of the existing building. The orientation of the 2 existing screw conveyors, who are feeding the FGR and boiler ashes to the new bigbag filling line, had to be modified to fit with the design of the new buffer hoppers. New steel structures for the support of the 2 buffer hoppers had to be installed on an existing intermediate floor inside the packaging building.
The mixture of FGR and boiler ashes are being filled in 1000 to 1250 kg bigbags with a ratio of 88% FGR and 12% boiler ashes. Moreover, the density of the FGR is varying between 0.5 and 1 Ton/m³ and this depending on the temperature and season. To achieve these requirements with the varying density of the product, control of the speed of the screw conveyors is crucial.
Also dust control was an important requirement for the customer. Delaere installed 2 dust hoods on the left and right hand side of the bigbag filling station and a third dust hood on the bigbag closing position. To reclaim the dust, these 3 dust hoods and the de-aeration outlet of the fill pipe are all connected to 1 de-dusting group positioned above the dosing screw conveyor for FGR. By means of a rotary valve installed on the outlet of the de-dusting group, the reclaimed product is discharged into the FGR dosing screw and brought into the packaging process again.
The bigbag filling line is installed in a harsh environment. Therefore C3 painting was applied on all the frames and structures of the bigbag filling line. SEW OS4 execution was considered for all the motors. The main electrical panel, control cabinet and junction boxes were supplied in stainless steel.
