APPARATUS FOR CRUSHING RELATIVELY SOFT MATERIAL SUCH AS COAL

INSTALLATION DE BROYAGE DE MATIERES RELATIVEMENT TENDRES, NOTAMMENT LA HOUILLE

English Abstract

Abstract of Disclosure
Apparatus for crushing relatively soft material such as coal,
said apparatus comprising a container for material entering
the apparatus and meant to be crushed, and within said
container a conveyor, which feeds the material to be crushed
in between crush rolls belonging to the apparatus. The
conveyor consists of a screening roll set, through which the
material conforming to the permissible grain size is screened,
and that immediately after the crush rolls there is a
screening means by which the crushed material is separated
from uncrushed, undesirable objects such as stones and pieces
of wood.

Claims

Claims
1. Apparatus for crushing relatively soft material such as
coal, said apparatus comprising a container for material entering
the apparatus and meant to be crushed, and within said container
a conveyor feeding the material to be crushed in between crush
rolls belonging to the apparatus, wherein the conveyor consists
of a screening roll set through which the material conforming
to permissible grain size is screened, and that immediately
after the crush rolls there is a screening means by which the
crushed material is separated from uncrushed, undesirable
objects such as stones and pieces of wood.
2. Apparatus according to claim 1, wherein the conveyor is
upwardly inclined a few degress in the conveying direction.
3. Apparatus according to claim 1, wherein in association
with the conveyor there is a precrusher.

Description

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The present invention concerns apparatus for crushing relatively soft
material such as coal, said apparatus comprising a container for the
material arriving in the apparatus and meant to be crushed, and a conveyor
within said container, feeding the material to be crushed in between crush
rolls belonging to the apparatus.
The ob~ect of this invention is to provide a new type of apparatus which
presents remarkable advantages over any`apparatus known in the art. The
apparatus of the invention is characterized in that the conveyor consists
of a set of screening rolls, through which the material conforming to the
permissible grain size is screened, and that immedi~tely after the crush
~olls there is a screening m~ans by which the ~rushed material is
separated from uncrushable, undesirable objects such as stones-and wood
parts. By the aid of the invention the size and power of the crush rolls
can be reduced because a very large proportion of the material to be
crushed is screened out earlier already and is not compelled to pass
through the rolls. The screening means located after the crush rolls
screens out the undesirable components in the same apparatus, and no
separate screening means is therefore needed.
One favourable embodiment of the invention iG characterized in that the
conveyor is upwardly inclined in the conveying direction a few degrees.
When the mass flow is set in a slightly ascending motion, this enhances
the screening effect.
Another embodiment of the invention is characterized in that there is a
precrusher in association with the conveyor. The prescrusher ~lreaks up
the largest pieces, and at the same time smaller crushed pieces are
produced, which become separated with the aid of the screening roll set~
The invention is described in the following with the aid of an example
with reference being made to the attached drawing, presenting the
apparatus of the invention in sectional view.
The apparatus comprises a container 1 for coal material arriving in the
apparatus and which is meant to be crushed. The container houses a roll
conveyor 2, feeding coal material to be crushed in between crush rolls 3,4
belonging to the apparatus. After the crush rolls there is disposed a
screening means 5 by which the crushed coal 6 is separated from uncrushed
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stones and wood pieces 7. The conveyor consists of a set of screening
rolls, through which the pieces 8 of the material arriving in the
container 1 which have been crushed to final size are screened out. The
conveyor is up~ardly running in the conveying direction to the extent of a
few degrees. In connection with the conveyor 2 there is a precrusher 9,
which crushes the largest pieces to be suitabIe to enter the crush rolls.
The coal material to be crushed is supplied into the container 1 belonging
to the apparatus, where the screening roll set 2 separates the pieces of
coal 8 found in the material which are of suitable size already. The rest
of the coal material goes forward to the precrusher 9, where the largest
pieces are crushed to smaller size. In connection with the precrushing
also smaller pieces of coal 10 are pr~duced, which are screened in the
screening roll set and fall therethrough. The actual crushing takes place
between the crush rolls 3,4. Stones and pieces of wood are also carried in
between the rolls 3,4, and ln that event one of the rolls, 4, yields
elastically, enough to let such pieces pass through. These ~ieces are
separated by a screening ~eans 5 located beneath; All crushed pieces end
up in a fluted conveyor (not depicted in the figure) under the apparatus
and are carried onward thereby.
Since a very great part of the coal material already as it arrives in the
apparatus is in such form that it can be screened with the screening roll
set 2 directly through the apparatus and therefore need not go through the
crush rolls 3,4, the power requirements of the crush rolls is remarkably
less than in any apparatus of prior art.
It is obvious to a person skilled in the art that various embodiments of
the invention may vary within the scope of the claims stated below.