Article
Project:
Bangladesh
Dhaka, 1999
1. Situation
City vegetable Oil Company is a growing and dynamic company in Bangladesh. At
the plant in Gandaria - Dhaka, beside the oil extraction activity, Peas and
Mustard seeds are unloaded from ships then weighed and bagged.
- 1.1 Before
- The ships were unloaded mainly by hand, baskets or bags were filled and
carried out of the vessel. Then the bag or basket emptied and returned to the
queue.
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- 1.2 After
- NEUERO GSD 250/220 TA12
- The unloading of the ship and direct filling of weighing and
bagging machines is now directly handled.
- A mobile pneumatic ship unloader type GSD 250/220 TA12 in
suction-pressure mode is responsible for an efficient and faster
operation.
- The ship lead time, the grain loss and the required man power is
reduced with direct consequent reduction of the operation costs.
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Suction-pressure conveying
- Material and air enters the intake nozzle and is separated at the
cyclone/airlock. The material falls through the airlock and is
picked up with the same air but now pushing the material. At the
pressure cyclone, the material falls down and the air goes up.
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- Pressure bends
- At assembly of the pressure line of the mobile pneumatic conveyor.
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- Scale and bagging
- A pressure cyclone at the end of the pressure line feeds a buffer
hopper of the scales - bagging machines at 100t/h rate.
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1.3 Consideration
A question that many times is asked. Is it ethical to use modern
machines in developing countries generating unemployment?
From the macroeconomic point of view, the use of a machine is freeing
work forces to do other jobs. The short time fate of each person is in
fact hard. This however is not consequence of the use of modern machines
but wrong or poor investment in education.
Man is driven to realise jobs faster and cheaper, in this specific
case reducing the food cost for the consumer as consequence.
This thoughts should be used for all kind of machines. Technology
should be incentive and not blocked because it must also consider the
total group of people in a society, not a specific one.
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2. Technical
Mobile pneumatic conveyors type GSD have following typology:
NEUERO mobile pneumatic conveyor number typology
GSD 250/250 D TA8 DA7,5
I I I I I I Pressure boom length (m)
I I I I I Suction boom length (m)
I I I I Diesel or Electric motor
I I I Motor power in HP
I I Conveying pipe diameter
I Suction-pressure blower (in German Gebläse Saug – Druck)
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- 2.1 Flexibility suction-pressure
- The pneumatic mobile conveyor can be operated in three modes:
- -suction only
- -pressure only and
- -suction-pressure combined
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- 2.2 Nozzle
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- An intake nozzle with adjustable air inlet attached to a flexible
pipe is showed in this figure.
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- 2.3 Boom
- TA12 boom is made in square profile with total of 12 m long and a
telescopic range of 4m, luffing of 50° and slewing of 310° grant liberty
of movements for operation.
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- 2.4 Turbo
- Material is conveyed by air movement. 2 turbo blower connected in series
bring the necessary air movement (volume and pressure). The air flow
regulator has the property to maintain the air volume in a defined range,
therefore adjust air speed and limit the power consumption.
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- 2.5 Mobile
- Chassis with rubber tyres and brakes makes this equipment suitable for
moving.
- 2.6 Remote Control
- A pendant remote control for the movements of slewing (310°), luffing
50° and telescoping 4m.
3. Operation Maintenance
Operation and Maintenance are key issues, specially in areas where parts are
difficult to supply.
- 3.1 Simple
- Pneumatic systems are simple and with less moving parts also less
susceptible to breakdown. This is important because of ships cost.
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- 3.2 Safety
- Suction nozzle in the material moved by slewing, luffing and telescoping
the boom. The movements are slow and the system is safe also for operators
inside the hatch.
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- 3.3 Easy
- Simple and slow movements to move the nozzle into the material. The use of
a pendant control with buttons is easy to learn. Normally a week should be
planned for assembly installation and training.
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4. Cost
- The cost of such machines normally are questioned in cheap labour
countries but the mobile units are a good solution for capacity increase
and/or cost reduction.
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- 4.1 Energy
- The energy consumption must be taken into account. In places where
energy is rare, a diesel powered machine can be used.
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- 4.2 Material loss
- The enclosed system from the hatch to the bin, truck or other
destination grant the product against contamination and losses.
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- 4.3 Spillage
- Material is conveyed directly from the hatch to destination without
material loss.
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- 4.4 Standard equipment
- The use of a standard machine takes a benefit of reduced cost. A
characteristic of pneumatic conveyors is the flexibility and adaptation to
new layouts, specially important in fast growing facilities.
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