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| ARMOURED
CONVEYORS |
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| Manufacturing General
Program |
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| Twin central
chain armoured conveyor. |
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Armoured conveyors
are the ideal transport mean for high efficiency cuts. They
were mainly developed for their application in the coal mining
industry and soon became very popular in other mining industries,
in the construction industry and civil works and in the stone
and quarry industry. Their adatability to any circumstance,
their robust construction, their easy operation and maintenance
and, consequently, their full ability assure their profitability
and have contributed to make the armoured lateral and central
chain conveyors the standard transport and raising system in
many mining countries wordwide.
The conveyor is made up of a series of channels which, in addition
to guide the chain and to transport the raised coal in the integral
systems of longwalls, also provide a safe guinding for the raising
machine. They are used as a counterweight for the propping logs
connected to the propping logs connected to the conveyor when
they move forward as wel.
In the short lenght conveyors, the chain returns by means of
a transfer station directly linked to the groove mill. |
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conveyors with lengths up to 50 m and for distribution conveyors,
the use of a tensioning transfer station is recommended. It
is mechanically and hydraulically operated and provides the
required tension every time. For longer conveyors, a non-tensioning
transfer station is installed. In this case, the chain is tensioned
by means of a tensioning device. |
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When
the transfer station is mechanically tensioned, the chain tension
is set by means of tensioning screws that operate on the transfer
drum while when the transfer station is hydraulically tensioned
the chain tension required is obtained extending it towards
two hydraulic rollers operated with a water an oil olution or
a fat solution. The transfer stations are supplied with in-built
pulley drums or chain stars.
The latest is preferred to the previous one since it provides
a detter chain guiding.
The drive stations offer a very compact construction al different
levels and can be used for single or twin drives.
Their sides are provided with drills suitable for fixing reducers
or drive sets. These transfer stations can also be installed
in the conveyor´s transfer, as an auxiliary motive station.
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| Twin lateral
chain armoured conveyor. |
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The
drive stations include a hauling drum with chain stars and rigid
coupling. The hauling drum is bipartite, the semi-drums encircle
the reducer output shaft or the blind bearing if it just has
a drive set. In certain driving stations, the contact surfaces
of the semi-drums have scratches that provide the set with a
high torsion resistance. The torque transmission is performed
with keys. |
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| Single central
chain armoured conveyor. |
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The
transport channels are made up of sigma shaped side profiles
wiht different thickness and heights. They are highly dending
resistant and are linked through a special welding to bottom
plates, which has different thickness and qualities as well,
sometimes reaching a tensile breaking strength of 1.000 N/mm2
and a hardness of 360/440 HB. This results into an extraordinary
resistance, a great wearing reserve and a number of hours of
operation which assure the raising of a remarkable quantity
of tonnes with no general revision needed.
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| Twin central
chain armoured conveyor with inbuilt crusher. |
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| Crusher type
500 / E-2. |
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In the case of
the lateral chain channels, they have been considerable armoured
with hard manganese steel ends and can be exchandeable with
those channels without that kind of reinforcemente.
The length of the channels is 1.500 mm. Adaptation channels
of 500, 700 or 1000 mm lenght are sometimes supllied and can
be mounted between two channels in any point of the conveyor.
In order to increase the useful transversal section, rise plates
screwed into the sifma profile outer side are mounted. |
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Guiding
plates for the plane or for the crosscutter can also be installed.
Their design is varied depending on the conveyor size and if
it is a lateral o central chain conveyor. The assembling, coupling
or trasition channels are used to link the groove mill to the
drive or transfer station.
Their design allows the tensioned strand of the portative chain
to prefectly fit the chain sprocket, with no wearing.
The profiles are considerably reinforced in order to be able
to support the high twisting times of the motors as well as
the efforts suffered when the conveyor is shifted and when this
type of channel is linked to the driving frame. |
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The
use of two lateral chains and one central chain for those conveyors
equipped with a crusher is recommended. The central chain is
not activated in order to avoid the links deformation.
When compared to lateral chains, the central chain has the following
advantages:
·The central chain receives the whole traction load while
in the case of the lateral chains, the load is necer equally
shared by both branches.
·The blockage is not possible due to the disposition
of the links and the chain. In case of blockage and when a twin
lateral chain is used, the traction load considerably increases
and is focused on the chain. This provokes its enlargement or
ruptures. |
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| Armoured
abstractor type EMT-1000. Driving drum with three haulage
stars Z=8. Distance between lateral chains, 1000 mm. Scrapers
mounted each 736 mm. at staggered between chains separated
500 mm. |
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Conveyors
can be fitted with twin lateral chain, twin lateral and one
central chain or with with single or twin central chain. Thanks
to its compact and resistant links, the chain assures an efficient
conveying of all the material loaded. Only the central chain
assembly can be perfectly included in the curves. In a certain
way the turning circle of the curve depends on the distance
between the links. The twin lateral chain assembly is not adequate
to be included in the curves. |
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| Armoured
abstractor EMT-1000. Lateral spill plates of 1000 mm.
high. |
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The links obliquely
located do not disturb the operation with just one chain. For
twing lateral chain conveyors, when a links is bended or when
the chain is enlarged, it can jump on the star, provorking breaks
of the joint pieces and of the chains.
For crushing on the conveyor, a continuous crusher is installed.
It is integrated in a mining gallery conveyor of a coal working
or of any other working.
It is used for coarse-crushing (precrushing) of the raised coal
so that this coal can still being conveyed by a linked belt
conveyor. |
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The
material to be crushed is conveted by the gallery conveyor through
the crusher. At this stage the biggest coal fragments are crushed
by the crushed rotor while the smaller pieces are conveyed under
the rotor.
The crusher can make combination of the fragments from a 1 x
1 m. cross section and a fragment weighing up to
2 t. |
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The
crusher output depends on the rotor rim speed, on the clearance
height under the rotor and on the conveyor speed. Its output
can reach 1.500 t / h.
The clearance height under the rotor can be set with four laggings
35 mm. thick, obtaining a 140 mm .setting height.
The grain size is reduced from 0 to 300 mm depending on the
clearance height under the rotor.
The installation of this type of crusher conveyors with two
lateral chain and one central chain is not recommended, even
if it is used.
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| Armoured
abstractor EMT-1000 with capacity for 1600 t/h and variable
speed from 0,15 to 0,40 m/s with a frecuency changer.
Power 75 kW. Length 25,2 m. Three chains of 26x92 mm.
diameter, and distanced 500 mm. |
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