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A high density alumina ceramic venture
encased in HDPE. |
Composite Hdpe/Ceramic Innovation On Tailings Line Venturis
In slurry transportation applications
it is important, irrespective of the distance over
which the material is moved in a pipeline, that
material flow is controlled for various reasons
including protection against wear.
It is generally argued that increase in velocity can
effectively increase wear depending on the
application and nature of the product. Inversely,
slowing material velocity will decrease the wear
rate.
Fritz Schoeman, engineer at Multotec Wear Linings
explains that venturis are used within the pipelines
to restrict slurry flow, thereby controlling
material velocity and for necessary energy
dissipation at choking stations. |
“As a norm the restriction of flow in a slurry pipeline is
facilitated through the use of metal or polymer orifice
plates. However, these can be troublesome, requiring regular
costly maintenance,” Schoeman says.
Multotec Wear Linings has devised a simple, yet effective,
alternative for this application using a high density
alumina ceramic venture encased in HDPE. Major advantages of
this abrasion and corrosion resistant innovation are that it
can be custom engineered for a variety of pipeline
applications and is environmentally friendly.
Schoeman says that the principle of operation is fairly
straightforward. “The material moves through the throat of
the venturi, which is designed to accommodate the specific
pressure requirements of the individual pipeline resulting
in a reduction in downstream pipeline pressure and slurry
velocity.
The high density polyethylene (HDPE) pipe is lined with an
isostatically pressed wear resistant ceramic lining that has
been engineered for its specific design requirements.
“Aspects to be considered would include the throat diameter
and length as well as the total length of the venturi. We
also determine the inlet and outlet angles to acquire more
favourable flow. Specialised technology is used to adhere
the ceramic to the HDPE casing and we have had previous
successes on bends, straight sections and now in a venturi
which has been installed in a kimberlite tailings line,”
Schoeman says.
“Multotec Wear Linings has a team of technical experts
capable of analysing specific slurry pipeline requirements
to ensure that the most appropriate cost effective solution
is provided. “In addition to the venturis, this ceramic
lined HDPE concept can also be applied to bends as well as
sections close to the choke stations and venturis,” Schoeman
says.
The use of HDPE has seen substantial increase in service
over the last years. It is relatively lightweight and
inexpensive, has excellent corrosion resistance properties
and is ideal for slurries that are uniformly abrasive.
“Lining HDPE pipes with engineered, high density alumina
ceramics provides a corrosion resistant system that can
accommodate extremely abrasive slurries at pressures up to
2500 kPa,” Schoeman says.
Multotec Wear Linings’ engineering department is staffed by
individuals who have specialist experience with wear
resistant lining materials and the company has a reference
base of successful installations across all minerals
sectors.
“It is our ability, through the use of innovative thinking
and technology, to be able to provide wear lining solutions
to the required dimensions at the request of customers and
end users, combining the benefits and material properties of
ceramic as well as other components of the composite
including HDPE or any other material,” Schoeman concludes. |
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