The FEEDER receives the material and introduces it to the MULTIBELT conveyor.
The conveyor runs vertical and horizontal without a transfer point up to the discharging point. The belts run inside the AIR BOX that has a special seal to minimize air losses.
Hydraulic cylinders are used for kick in, kick out and luffing movements. A slewing movement and travelling completes the different movements.
The operation can be carried out from the operator’s cabin or via radio remote control from the ship’s deck.
The low power consumption compared to any other continuous unloader makes it possible to work with 0,25 kWh/ton.
The design of the MULTIBELT allows unloading almost all material left in the ships hold, leaving only approx. 5 ton that needs to be lifted out. Please compare this to other continuous systems like chain elevators.
The MULTIBELT unloader is available with capacities between 600 t/h and 1.200 t/h. The speed of the screws and thrower can be adjusted by the operator to get the desired capacity.
2 rotating screws, one left and one right brings the material to the centre where the thrower is located. The thrower has bolted shovels and introduces the material between the carrier and the cover belt. The speed of the screws and the thrower can be adjusted to get the best capacity.
The FEEDER is driven by an independent hydraulic pack located on top of the FEEDER box.
The FEEDER box has a dust collecting point connected to a central filter located on the machinery house platform.
MULTIBELT conveyor inside the air box
The material is conveyed between the carrier and cover belt, inside the air box. The air box has a positive pressure that keeps both belts together. The air box has a special seal to avoid air losses.
The cover belt elongates in the width in order to accommodate the material in between. A centrifugal fan creates the positive pressure that keeps both belts together.
The vertical boom accommodates the FEEDER and the MULTIBELT conveyor. The kick in and kick out movements are effected by using hydraulic cylinders. The vertical structure is connected to the dynamic counterweight system.
The horizontal boom is pivoted with the vertical boom. The MULTIBELT conveyor runs on an air cushion belt up to the discharging point.
Machinery house platform and discharging point
The machinery house platform incorporates several functions.
At the discharging point the material leaves the MULTIBELT conveyor. A chute feeds a conveyor that delivers the material to the quayside.
The electric room contains all electric panels, MCC and PLC.
The dust suppression filter system receives the dust from the different transfer points and feeds it into the mainstream product flow.
Hydraulic power pack and hydraulic cylinders for the upper part movements are installed as well at the machinery house platform.
The dynamic counterweight is a movement connection between vertical boom and counterweight. The movement of the vertical boom makes the counterweight change its position.
The main advantages of this system are weight economy and constant feeder pressure independent of the FEEDER position.
Power and control
The MULTIBELT unloader can be powered using a power cable drum or using a Diesel Generator Set. The communication to the quayside installation can be via radio, optic fibre or cable. The automatic unloading operation of the MULTIBELT is possible using level indicators at the FEEDER.
Gantry conveyor and travelling
The gantry supports the belt conveyor which receives the product from the discharging point. This belt can incorporate a belt scale which indicates the capacity of the MULTIBELT unloader. This is very useful for the right operation settings.
This is an important point to get the real cost and reliability. Chain flights, screws or buckets runs with different speed than the material flow, causing wear. This wear is not only located at the vertical leg but also in the horizontal casings and intermediate bearings.
This problem is solved with the MULTIBELT because the belt and material are running at the same speed.
At the screws and thrower of the FEEDER the wear is limited to replaceable bolted segments and is located in an area of easy access.
The MULTIBELT is equipped with slow speed belt motion and local movement control that allow an easy and safe inspection.
Foreign materials are affecting all continuous systems and can cause operations stop. Screw and chain may jam with foreign bodies and the belt can be damaged at the MULTIBELT. Foreign body sensors and automatic stops minimize the problem.
In case of damage, the belts can be patched or be exchanged. Normally the change and vulcanisation is done at preventive maintenance and requires approx. 24 hours.
Routine inspections and preventive maintenance instructions are shown in the operating instructions handbook.
|Horizontal Boom||22 m|
|Vertical boom||26 m|
|Max. Vessel size||80.000 dwt|
|Belt width||1.300 mm|
|Main drive||200 kW|
|kW consumption||approx. 300 kW|
|Slewing speed||0,16 rpm|
|Slewing range||< 360°|
|Luffing speed||< 0,2 m/s variable|
|Luffing range||-30° to +35° (+55° at parking)|
|Kick In-Out||< 0,2 m/s variable|
|Kick In-Out range||-30° to +35°|
|Weight||~ 250 ton|