SINTER CRUSHER WITH HARD FACING

BROYEUR DE TRAVERTIN

English Abstract

Abstract
A sinter crusher in which the working angle between
the carbide working surfaces of the rotating breaker arms and
the horizontal griddle bars is smaller than the friction angle
of sinter to carbide. In addition, the working surface of the
griddle bars is sloped toward the inclined feed shoot at an
angle of 8-15° to the horizontal and the working surfaces of
the breaker arms are arranged such that the end towards the
breaker arm shaft in relation to the connecting line from the
other end to the center of the shaft will form an angle of
?8° between the connecting line and the working surface. Further-
more, the distance between integral hold-backs and the dis-
charge edge of the inclined chute is 40-50 cm while the dis-
tance between the discharge edge and the breaker arm tips is
equal to one-half the distance between adjacent griddle bars.
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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A sinter crusher, consisting of a driven shaft
with breaker arms, horizontal griddle bars under the shaft,
with the breaker arms reaching through the griddle bars, a car-
bide layer on the working surfaces of the breaker arms and the
griddle bars, as well as a sloped chute in front of the griddle
to deliver the medium to be crushed, is characterized by
working surfaces of breaker arms and griddle bars which in the
working area are arranged at an angle to each other which will
be smaller than the friction angle of sinter to carbide.
2. A sinter crusher according to claim 1
characterized by hold-backs on the shaft to shorten the dis-
tance between the shaft and the discharge edge of the chute
in front of the griddle.
3. A sinter crusher according to claim 2
characterized by a distance between hold-backs and the dis-
charge edge of 40 to 50 cm.
4. A sinter crusher according to claim 2
characterized by hold-backs which are integral parts of the
breaker arms.
5. A sinter crusher according to claim 1
characterized by working surfaces of the griddle bars which
are sloped towards the chute.

6. A sinter crusher according to claim 5
characterized by working surfaces of the griddle bars which
are sloped toward the chute at an angle of 8 to 15° to the
horizontal.
7. A sinter crusher according to claim 6
characterized by working surfaces of the breaker arms which
are arranged such that the end towards the shaft in relation
to the connecting line from the other end to the center of
the shaft will form an angle of ?8° between the connecting
line and the working surface.
8. A sinter crusher according to claim 7
characterized by a distance between the breaker arm tips and
the discharge edge of the chute which equals half the dis-
tance between two adjoining griddle bars.

Description

1~40ZZ
Specification
This invention describes a sinter crusher, which
consists of a driven breaker shaft with breaker arms, a hori-
zontal grate under the shaft with the breaker arms reaching
through the griddle bars, a carbide layer on the working sur-
faces of the breaker arms and the griddle bars, as well as a
sloped chute in front of the griddle to deliver the medium to
be crushed.
The sinter coming from a sinter plant is delivered
in large interlocked lumps in the form of sinter cake, which
must be crushed for further processing. ThiS is done with
sinter crushers which force the sinter cake through a griddle
~ith its breaker arms, thus crushing the lumps. Both the
crusher arms and griddle bars are subject to considerable wear
as well as high thermal stress. This thermal stress is due
to the sinter which arrives in hot condition, and/or the heat
which the crushing operation generates. Breaker arms and
griddle bars will thus wear rapldly and must frequently be
exchanged.
To extend the life o~ the breaker arms and of the
griddle bars, they can be lined with wearing parts (German
Patent Publications 1,121,436; 1,229,822; 1,657,666;
2,216,120), or lined with carbide (U.S. Patent 2,57~,426;
German Patent Publication 2,234,019). In addition, breaker
arms or griddle bars will be cooled by cooling media flowing
through them (German Patent Publications 2,234,019; 2,216,120).
The use of wearing parts will extend the life of the
components thus protected, but will increase costs of fabrica-
tion or repalr. This is also the case for carbide layers. The
process of cooling o~ breaker arms and griddle bars is quite
costly.
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iO~4022
This invention attempts to extend the li~e of the
carbide-clad sinter crushers, without the necessity of cooling.
This task will be accomplished by arranging the working sur-
faces of the breaker arms and the griddle bars at such an angle
to each other that this angle will always be smaller than the
friction angle of sinter in relation to the carbide surfaces.
The working surfaces of the breaker arms and the
griddle bars are those surfaces which will have contact with
the sinter during crush~ng. The carbide tipping is being pre-
ferred in sintered condition. The friction angle of the slnteris that angle between the working surfaces of the griddle bars
and the breaker arms, by which the ~inter cake will not slide
towards the open side of the angle during crushing. This
angle is normally about 30 to allo~ for an arrangement of
breaker armfi and griddle bars in an angle of less than 30.
A preferred design for this invention con~ists of
hold-backs on the breaker shaft, to shorten the distance
between breaker shaft and disc~arge edge of the sloped chute
in front of the griddle. I~e sinter cake can thus slide only
partially into the ~orking range of the crusher, while the
remaining portion is still on the chute. The discharge edge
of the chute ~ill thereby act as separating step, and thus
prebreak or aid in the process of breaking by e~ualizing the
sizes to be crushed.
A preferred design provides for a distance between
the hold-bac~s and the discharge edge of 40-50 cm. This
dlstance has shown very good results.
A preferred design makes the hold-backs integral
part~ of the breaker arms. This makes for a simplified con-
struction which achieves excellent strength of the breaker arms.

iO84~2Z
A preferred design provides for a sloped working
~urface of the griddle bars towards the chute, thus creating
excellent crushing conditions.
A preferred deæign arrange~ the working surface of
the griddle bars in an angle of 8-15. mls angle ald~ in the
crushing process.
A preferred design arranges the working surfaces of
the breaker arm~ so that the end towards the shaft in relation
to ths connecting line of the other end to the center of the
shaft ~or~s an angle bet~een the connecting line and the working
~urface of +8. This arrange~ent will further ~inialze
squeezlng and friction during the crushing proce~s,
A preferred de~ign place~ the distance of the tip of
the breaker arms from the discharge edge of the ~loped chute
to be half the distance between t~o adjoining griddle bars.
This ~ill al~o reduce squeezing and friction during crushing.
The invention ~111 be explained by the sche~atic
sketches.
Figure 1 is a ~ide view of the crusher; and
Flgure 2 i8 a front view seen from the chute end.
The working surface~ 1 of breaker arms 2 and grlddle
bars 3 ~ e ~ormed by the ~urface~ of the carbide layers 4.
Wor~ing sur~ace 1 of carbide layer 4 and griddle bars 3 forms
an angle B of 8-15~ to the horizontal in direction of sliding
sur~ace 8. Working ~ur~ace~ 1 of carbide layers 4 on breaker
ar~s 2, and working surfaces 1 of carbide layers 4 on griddle
bars 3 are arranged iD an angle C of less than 30 within the
working range of the griddle. Thi~ angle C ~ill be less than
30 ~hen the cru~htng operation start~, and it will decrease
~uring the cru~hlng proce~s. ~reaker arms 2 are arranged on

0A~;Z
shaft 5~ These breaker arms 2 are designed in such a way that
hold-backs 6 become integral parts of breaker arms 2 which
shorten the distance between shaft 5 and discharge edge 7 of
chute 8. The sinter cake 9 can thus only partially slide into
the operating range of the cru~her, while discharge edge 7 of
chute 8 will act as prebreaking step. Working surfaces 1 of
breaker arms 2 are located in such a way that the end towards
shaft 5 in relation to the connecting line from the other end
to the center of shaft 5 will form an angle A between the con-
necting line and working ~urface 1 of +8. The distance ofthe tips of breaker arms 2 to the front of discharge edge 7
of chute 8 equals half the distance betwsen two adjoining
griddle bars 3.
The advantage~ of this invention l~e in the geometry
of the crushing process, whereby a rapid crushing operation will
take place, thus reducing the heat-up of breaker element, and
reducing the wear of carbide layers as ~ell as of the crusher
a6 6uch. The wear of breaker elements within the actual opera-
ting area will thus be reduced considerably, which results in
a considerable reduction of carbide cos~s. Because of minimal
squeeze and friction during crushing, the accumulation of
rejects will be held to a minimum.