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The
PRECIOUS Hammer
Mills are durable utility grinders capable of grinding most
free-flowing materials. Hammer mills operate on the principle
that most materials will grind or crush upon impact with the
hammers. The Precious Hammer Mill are designed for fine crushing
of soft up till medium hard, non abrasive and non adhesive materials,
such as bituminous coal, limestone etc.
A
large application of hammer mills can be seen in cement factories
and in lime works foe preliminary crushing of bituminous coal
for treatment of lime stones, for sintering purpose and according
to the needs even in other industrial branches. Their advantages
is a high degree of crushing, high performance, a possibility
of change of granulometric composition of the product within
a large range an easy access to the internal compartment and
consequently an easy operation and maintenance of the machines.
Operating area of the Precious hammer mills can be heated
by means of hot gases and thus conditions are created for
treatment of materials with a higher degree of moisture.
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Description:
Main parts of the PRECIOUS hammer mill are a welded case, rotor
with hammers, grates and drive. The case of the hammer mill
consists of lower and upper three parts portions. The middle
part of the upper portion is fixed to the charging hopper, while
the lateral parts which are lined with grooved armours can be
lifted around revolving hangers either hydraulically or in case
of smaller sizes, manually. In the lower part of the case are
adjustable discharge grates, the position of which as against
the concerned space can be adjusted by means of upper and lower
regulation, placed on the exterior side of the lower part of
the case. In the crushing compartment delimitated by the upper
part of the case and by the grates turns the rotor consisting
of a shaft and of a number of disks through which are passed
bars of hammers. On the bars are fixed the hammers in a rotary
way. The drive consists of a dust-proof electric motor of a
closed structure, connected with a flexible coupling or through
transmission by means of vee- belts with shaft of rotor. A particular
attention during the stage of development of hammer mills was
devoted to easy service and maintenance. Hydraulic or mechanical
lifting equipment facilitates access to the whole upper half
of the rotor without a difficult disassembly of the entry part;
thus it shortens substantially outage time during repairs of
the machines and during the exchange of hammers.
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Operation
of the mill:
The
material is fed into a hammer mill from the top and by gravity
falls into the grinding chamber. The material is contacted
by a series of rotating hardened hammers. The material
is ground by repeated contact with these hammers, contact with
the walls of the grinding chamber, and particle to particle
contact. The material remains in the grinding chamber
until it is suitably sized to pass through the perforated screen
that covers the bottom half of the grinding chamber. We
offer interchangeable screens with whole diameters from 2"
to 1/64" to allow for course or fine grinding of most any
product. The output (volume) of the hammer mill is dependent
upon the screen size, shaft speed (normally 3,600 rpm), and
the configuration of the hammers. We offer hammer
mills with bottom discharge (gravity fall) and we offer hammer
mills equipped with material handling fans (recommended for
finer grinds). Precious hammer mills may be belt
driven or direct driven to fit your specifications. As
a consequence of symmetric design the mills can be operate in
both directions of rotor rotation they are reversing. The material
to be crushed arriving in to the crushing area through the entry
orifice comes into a direct contact with the hammers; the hammers
rotating at a speed of 35 ÷ 60 m.s -1, both crush the
material and throw it against the armour plating of the upper
part of the case. Here the material is crushed furthermore rebounds
back and is pulled down by the hammers to the grate, where the
milling process comes to the end. Material of a required fineness
falls down through slots in between the grate bars. Dimensions
of the slots can be chosen according to the needs from 10 to
40 mm, the slot of 10 mm width being the standard dimension.
Composition of the granulometry of the product going out can
be changed within large limits by changing the arrangement of
the outlet grate and of the milling path.
We can configure our hammer mills to best suit your application.
We are happy to test grind any product free of charge.
If you are interested in sending a product for test grinding
please contact us. By test grinding your product we are able
to prove the capability of our hammer mills and determine the
proper model and set up (bottom discharge or material handling
fan, and belt drive or direct drive) to suit your needs. |
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