Theory ::
Dense Phase
Pressure Conveying Systems generally use compressed air at above 1 Bar g to
push materials from a Pressure Vessel
(also known as a sender unit or pressure pot) through a pipeline to the
destination where the air and product are separated by a filter or other system. The product extrudes through
the pipeline, initially at low velocity, and gradually accelerating towards the
destination.
>> Systems
generally operate on a batch basis as follows: (simplified) <<
Fill
the sender unit with product to be conveyed.
Pressurize
with compressed air
Open
discharge valve until the product has been conveyed out.
Close
discharge valve and refill vessel.
A panel of valves and sensors are used to control the air
pressures and velocities at all parts of the system to ensure smooth reliable conveying
of the product.
Applications ::
Dense Phase Pressure Conveying Systems are particularly
suitable for systems, which convey materials at high capacities over long distances, to multiple destinations. Most
systems include several air control valves and the high pressure compressed air
supply is able to overcome the pressure
drop generated by the most difficult materials, while also providing controlled
conveying for friable materials. The
lower convey velocities also extend the service life for systems conveying
abrasive materials.
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Convey Rates :
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High, up to 100 tonnes/hr or higher
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Convey Velocities:
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Low, 1-10 m/s
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Convey Distances:
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High, up to 500m or longer
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Air Mover :
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Compressor (Screw, rotary,
reciprocating)
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Operating Pressure:
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Up to 8 Bar g
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Material/Air Ratios:
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high, up to 150 kg/kg
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Note All values approximate,
refer Nu-Con for advice about how to convey your product.
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Options ::
To optimise the system various techniques are used to
reduce compressed air consumption and cost, and additional options for specialised
applications are available:
Air
injectors to fluidise materials to reduce friction
Pulsed
air injection to break up the product flow into discrete slugs
Line
Boosters to assist conveying along convey route
Vibration
to loosen cohesive powders prior to conveying
Twin
vessels to provide continuous conveying
In-Line
sifting, sampling, delumping, metal detection and magnetic separation systems
Stepped
convey lines to reduce terminal velocities, abrasion and degradation
Stainless
Steel construction for sanitation or corrosion resistance
Demountable
and polished designs to USDA 3A standards for ease of cleaning
