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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.
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.
Dynamic
counterweight
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.
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.
Maintenance
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.
Example for MB1200 –
80.000 dwt ships
Capacity 1.200 t/h
Horizontal
Boom 22 m
Vertical
boom 26 m
Max. Vessel
size 80.000 dwt
Belt
width 1.300 mm
Feeder
drive Hydraulic
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°
Travelling 12 m/min
Auxiliary
winch optional
Weight
~ 250 ton
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