Note: Descriptions are shown in the official language in which they were submitted.
d ~32 9 5Çi~
A687-007
PROCESS AND APPARATUS FOR REMOVAL OF
DEPOSITS AND LININGS FRO~ HORIZONTAL CYLINDERS
The invention relates to a process for the complete or
partial removal of deposits and linings in horizontal cylinders
which revolve around their longitudinal axis, particularly from a
rotary kilns such as those which are used in the cement industry,
and to apparatus for carrying out the process.
Backqround of the invention
Other than breaking out encrustations and furnace linings by
hand, two kinds of methods are known for this purpose. According to
one type of method chemicals are used for the removal of the
encrustations and deposits. Generally these are not suitable for
the removal of the furnace linings in rotary kilns. According to
the second type of method, a variety of mechanical approaches can be
employed in which rinsing, shaking, blowing, striking, pushing,
turning or scraping can be used with or without special drive
mechanisms and a variety of different apparatus can be used to break
out the deposits and the furnace lining in rotary kilns and then to
remove them. For example, German Democratic Republic patent No.
64,844 discloses the principle of a mechanical cleaning apparatus
which is additionally actuated with ultrasound. German Federal
Republic published patent application No.271,164 discloses a guided,
driven drill rod provided with cutting or scraping means. Other
cleaning methods that are known from various technical literature
sources have a variety of drawbacks, among them in some cases the
complicated method or complicated construction of the apparatus,
high cost, difficulty of maintenance, temperature sensitivity,
frequent down time and difficulty of operation. Of course, in
manual removi.ng methods high labor costs, strenuous nature of the
labor that is involved and the frequency of industrial accidents
provide substantial disadvantages.
Objecti~es oP the Invention
In accordance with the objectives of the present invention, a
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method and apparatus are provided for the total or partial breaking
out of deposits and furnace linings from horizontal cylindrical
tubes which are adapted to rotate along their longitudinal axis,
particularly in rotary kilns of the cement industry. This should
be carried out in a continuous manner either completely or
partially without the need for cooling it down, and providing
controllable depth and length of removal as well as forward
velocity control, with the apparatus having a geometric shape which
enables the breaking out of the deposit by itself or together with
the furnace lining and the forward velocity of which can be
conveniently controlled through the cylindrical tube.
It is to be understood that while in the specification and the
clai~s the invention is explained with respect to rotary kilns, the
method and apparatus of the invention is meant to be equally
applicable to horizontal or substantially horizontal tubular
cylinders which rotate about their longitudinal axis and require
the removal of encrustations and/or cylinder linings.
Brief summary of the in~ention
A process for the partial or total removal of deposits and/or
linings from rotary kilns having a longitudinal axis, comprising
introducing an elongated break off roller, having a longitudinal
axis into the rotary kiln, rotating the rotary kiln for causing
rotation of the break off roller within the kiln, disposing the
longitudinal axis of the break off roller at anacute angle with
respect to the longitudinal axis of the rotary kiln to bring abouta
motion of the break off roller along the longitudinal axis of the
rotary kiln, causing the break off roller to break off parts of the
deposit and/or parts of the furnace lining from the interior of the
rotary kiln, thereby to collapse the interior deposit layer and/or
interior arch structure of the refractory lining within the kiln.
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The invention further comprises an apparatus for the removal
of deposits from and/or linings of rotary kilns thak have a
substantially horizontally disposed longitudinal axis, comprising a
substantially conical break off roller having a larger end and a
smaller end, and further having elongated guiding means for the
disposition and guidance of further means thereabout, cutting means
for cutting and/or crushing matter to be removed from within the
rotary kiln, and disc means disposed about said elongated guiding
means for mounting said cutting means from the periphery of said
disc means. Suitably the apparatus further comprises stabilizing
means disposed at the larger end of said conical removing roller for
stabilizing and supporting said break off roller within the rotary
kiln, said disc means being disposed on said elongated guiding means
off center with respect to the longitudinal axis of the removal
roller. The apparatus suitably further comprises means for
retarding, stopping and/or reversing the motion in an axial
direction of the break off roller.
Description of the drawings
The invention is described with reference being had to the
attached drawings in which:
Fig. 1 is a longitudinal cross-sectional view of a rotary
kiln schematically showing in elevation the break off roller oE the
present invention, and a winch;
Fig. 2 is a schematic, vertical cross-sectional view of a
rotary kiln showing the apparatus of the present invention in one
phase of its movement, and without showing the stabilizing disc;
Fig. 2a is another schematic cross-sectional view of the same
as in Fig. 1:
Fig. 2b is a schematic, vertical sectional view of a cutting
disc having cutting teeth and roll off teeth, viewed from the
conical end of the break orr roller;
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Fig. 2c is a schematic vertical view of the cutting disc of
Fig. 2b, in the rotary kiln, with a stabilizing disc indicated
behind it;
Fig. 3 is a side elevational view of the break off roller of
the present invention; and
Fig. 4 is a schematic front elevation of the apparatus of the
present invention with the stabilizing disc, within a schematic
transverse cross-section o~ rotary kiln.
Detailed description of the invention
In the following the invention is described in greater detail
with reference being had to the attached drawing.
Figs. 1, 2 and 3 show a part of a horizontal rotary kiln of
practically any desirable length and desirable diameter which, by
utilization of its own rotary drive mechanism, is freed from
deposits and the refractory lining. A break off roller 1 is
utilized for this purpose. Suitably cutting discs 4 are arranged -
according to size and provided with replaceable cutting teeth 3 as
well as roll-off teeth 3 , that are arranged along the central
guiding rod 2, provide for the conical mantle shape of the device in
the area of the guiding rod. If desired, in a different embodiment
of the inventon the conical end of the break off roller can be
omitted, and the cutting disc can be provided with its teeth
arranged in identical pairs (not shown). As the rotary kiln turns,
the break off roller 1 moves with it in a double motion~ On the one
hand, this comprises a rolling rotation in which the cutting teeth 3
of the cutting discs 4 rhythmically impact in the instantaneous
bottom portion of the rotating kiln onto the deposit and the masonry
lining while also cutting into their surfaces, and on the other
hand, in a longitudinal movement due to the conical mantle shape,
which movement is in the direction of the pointed end of the break
off roller 1. This longitudinal motion overcomes the slight angular
changes due to the inclination of the rotary kiln as well as the
UlleVellrle~ OL Lll~ de~osit therein. In other words, the break off
roller both rotates and climbs within the rotary kiln as the latter
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is rotated. As shown in Fig. 2a, in a working position in the
rotary kiln 10 the break off roller 1 has its central axis disposed
at an angle, relative to the longitudinal axis of the rotary kiln.
The longitudinal motion of the break off roller 1 can be regulated
by retarding that motion through a cable 9 attached to its rear
end. The other end of the cable is attached to a winch 8 which is
outside of the rotary kiln. The winch 8 enables both a retarding of
the forward motion of the break off roller as well as it stopping it
entirely. The winch 8 can be any suitable cable winding mechanism
such as a drum and equipped with suitable controls known per se.
Figs. 2h and 2c illustrate the relative positions of the
cutting teeth 3 and the roll off teeth 3 and the arrangement of
the tips of the teeth in a circle of identical center points. Here
the selected pairing of the cutting teeth 3 and roll off teeth 3
shows the supporting function of the roll off teeth 3 when the
break off roller 1 reaches its maximum elevated position on the
walls of the rotary kiln until rolling down again to or towards the
bottom of the rotary kiln 10. In Fig. 2c the break off roller 1 is
shown in its desired position in the rotary kiln, whereby the
stabilizing disc 5 can be seen in this view behind the cutting disc
4. The adjusting elements 6 of the stabilizing roller are
functioning. It is in this position that most effective operation
can be achieved. The cutting disc 4 is disposed on the work surface
with a cutting tooth 3 and a roll-off tooth 3 of the lower pair
of teeth. When duriny the counterclockwise rotation of the kiln,
the break off roller 1 rolls down counterclockwise an~ impacts upon
the work surface, from its maximum elevatecl position, the roll off
tooth 3 of the rear, lower pair of teeth rests on the furnace
deposit, and the left upper cutting tooth impacts downwardly. If
the severity of the impact should be ameliorated, and the effect
should be converted into a more uniform rolling that shakes the
deposit 13, then Fig. 2c shows a possibility by adjusting the
stabilizing disc 5 which with adjusting elements 6 closely
approaching with their contact point the furnace deposit surface and
the roll off teeth 3 .
AS is snowrl in Fig. 2, the removal process taKes place
essentially in two phases. In the first phase, the break off roller
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1 shakes and loosens the interior layers by means of steady impact
of the cutting teeth so that the arch structure becomes so loosened
that in the second phase duriny constant rotation the loose pieces
become increasingly looser and then can fall down when the loose
piece reaches a top position during rotation. If the stabiiizing
disc 5 is mounted at the rear end of the break off roller 1, as is
shown best in Fig. 4, 2 and 2c, the stabilizing disc causes the rear
part of the break off disc 1 to lie outside the lowest point 15 of
the cross section 11 of the rotary kiln. As the break off roller 1
moves due to the rotary motion of the rotary kiln 10, during the
break off process the following effects are produced: (a) the break
off roller 1 moves, as shown in Fig. 4, relatively independently and
outside of the flow 14 of broken off material that moves against it,
whereby the resistance toward forward motion is minimized; and (b)
the arrangement of the stabilizing disc 5 as shown in Figs. 3 and 4
enables the forward movement of the break off roller 1 in the
direction of its pointed end even in those portions of the rotary
kiln where the deposit and the refractory wall were removed and only
a bare kiln surface is exposed.
The stabilizing disc 5 is provided at its periphery with a
number of radial adjusting elements 6 which are provided at their
outer ends with contact elements 7. These are uniformly distributed
throughout the periphery of the stabilizing disc 5. According to
the adjusted length of the radial adjusting element 6, the effective
diameter of the stabilizing disc can be adjusted to regulate the
motion and characteristics of the break off roller 1. The striking
or bite depth of the cutting teeth 3 as well as the maynitude of
their impact can be adjusted by changing the effective diameter of
the stabilizing disc 5 by means of the radial adjusting elements 6.
Furthermore, the nature of the motion of the break off roller can be
changed in the same manner from a noisy rhymthmical impact in the
case of smaller stabilizing disc 5 diameters to a more calm rolling
when the diameter of the stabilizing disc 5 is adjusted to a larger
size. In this manner, it is possible to minimize any damage that
could be caused by cutting teeth 3 to exposed steel wall surfaces of
the rotary kiln 10 or to intact parts of the refractory lining 12
~r.d~ are to be retained. This kind o~ ad~s~menl, o~ course,
permits that the break off roller be set only for removing the
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deposits 13 separately, without damaging the furnace lining.
Suitably in carrying out the process of the present
invention, the axial distance of the stabilizing disc 5 from the
first, the largest cutting disc 4, is greater than the size of a
stone or even its multiple. When the adjusting elements of the
stabilizing disc are fully extended, then the position of the break
o~f roller 1 is changed to the extent that the roll off teeth 3
b~come lifted out from their operational function and the break off
roller will tilt towards its pointed end. In this position the
larger end of the break off roller 1 is supported to a greater
extent by the stabilizing disc. The further the adjusting elements
of the stabilizing disc are extended, the less the penetration of
the cutting teeth into the deposit and kiln lining to be removed.
The impact intensity and removal results of the larger cutting discs
is reduced and the weight is displaced increasingly towards the
smaller cutting discs towards the pointed end of the break off
roller 1.
These cutting discs 4 require less energy due to their
geometric shape and their arrangement on the break off roller. It
is an advantageous feature of the present invention that due to the
geometric relationships the break off roller that is adjusted to the
conditions of the rotary kiln, will necessarily move along with the
moving rotary kiln into which it was introduced. There, due to its
own mass and the exchangeable working tools attached to it, it will
break out the kiln wall deposits and the kiln walls, as may be
re~uired, due to light impact, pushing and tearing forces. Thus,
according to the particular circumstances, the break off roller can
be constructed to have suitable mass, and can be articulated,
hollow, or variable in its mass, size, number of working tooling and
of desired cross section. Independently of such variables, the
break off roller has a conical shape which when inserted into a
rotating rotary kiln, will move in the direction of its pointed end.
At its rear end the break off roller is attached through a rope
connection to a winch. Functionally dependent from the use of the
winch, the conical shape of the break off roller guides in a
longitudinal and rolling motlon Inat overcomes the longitudinal tilt
of the rotary kiln. The winch enables the breaking, slowing or even
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reversing the movement of the break off roller in the longitudinal
direction. The break off roller can, by utilizing the rotating
drive of the rotary kiln, cover the entire inner cylindrical surface
of the kiln. The cross sec-tional shape of the break off roller has
a pronounced influence on the operating characteristics of the break
off roller. Thus an angular roller cross section will exert during
its rotation advantageously rhytmic impacts of increased force.
Furthermore, a break off roller of angular construction can elevate
itself from the bottom of the rotary kiln and thus from time to time
~ree itself from the flow of loose, broken out matter. The effect
of the break off roller during the constant rotation of the rotary
kiln, is substantially amplified by the fact that the shaken and
loosened deposit in the rotary kiln, as well as its lining, lose
their arch structure under the constant pounding and shaking and
will collapse under its own weight when the kiln rotation brings it
into a hanging, upper position. The size and outer effective
diameter of the stabilizing disc has to be adjusted according to the
shape and size of the break off roller. The disc stabilizes the
operation of the break off roller and its positioning in the
direction of its pointed end. This especially so, when tbe break
off roller moves along the inner surface of the rotary kiln which is
already free from its lining and any deposits thereon. Therefore,
the stabilizing disc can be constructed as compact or adjustably
articulated, and can be of various mass, position, or material. It
can be recognized that the stabilizing disc enables the break off
roller to assume a position which enables that the operation of the
roller is not unduly influenced by the main flow of the broken out
particles.
When the movement of the break off roller 1 is controlled on
an exposed steel wall against a flow 14 broken off material, the
radial adjusting elements are set so that, as shown in Fig. 3, the
cutting teeth 3 are lifted between the pointed end of the break off
roller 1 and the stabilizing disc 5. Thus, the main load rests on
the stabilizing disc 5, due to the shape of the break off roller 1.
The contact elements 7 should be made of a material which has a
suitable contact attachment properties to adjacent surfaces as well
as good weaL~ CildL ~ L istics ~ sucn as rough casting or hard rubber.
This can contribute substantially to the movement characteristics of
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the break off roller 1 at various tilt angles of the rotary kiln and
stabilized against the flow 14 of broken ~ff material.
When the direction of rotation is chosen to be counter
clockwise, then the break off roller 1 moves to its maximum
elevation within the rotary kiln, until the center of gravity of the
roller becomes labile and the roller tilts counterclockwise towards
the bottom of the kiln. Since the roller has a conical form in this
preferred embodiment, its rolliny down or tilting distances of the
cutting discs 4 are longer at the larger end than at the smaller
one. This results in the longitudinal axis of the roller assuming a
tilted position, with respect to the longitudinal axis of the rotary
kiln which is constantly rotating. This movement of the break off
roller from the bottom of the kiln to a maximum vertical elevation
and back, is continuously repeated due to the con~inuous rotation of
the rotary kiln. At the pointed tip, the roller describes a
pendulous motion with the axial position of the roller relative to
the axis of the kiln. This pendulous motion is obtained by the fact
that the length of the break off roller is generally larger than the
diameter of the rotar~ kiln. In this procedure the deposit is
removed separately, partially or totally, until the furnace lining
becomes exposed, and when required, also the lining is removed.
The break off roller 1 is made as a robust, preferably
conically-tipped, cylindrical body, having sufficient mass and size,
provided with teeth, so that it is set to passive rotation by and
within a rotary kiln that is rotated about its longitudinal axis.
This rotary motion is converted by an advantageously polygonal
cross-sectional structure of the body of the break off roller 1,
into rhytmic impacting of the break off roller onto the surface on
which it rotates, whereby the teeth 3 and 3 will manhandle the
deposit layer 13 and the furnace lining 12 and cause them to
collapse through destruction of the arch structure. The conical
construction of the break off roller assists in it achieving a
slight inclination relative to the longitudinal axis of the rotary
kiln and this divides the relative movements of the break off roller
into two main components.
One of the components of movement of the break off roller is
vertical to the longitudinal axis of the rotary kiln. When the
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movement is not impeded, then the second component of movement of
the break off roller, is parallel to the longitudinal axis of the
rotary kiln. When the winch 8 is subjected to a retarding breaking,
then the second component of movement changes to a varying
longitudinal force, the magnitude of which depends from the weight
and total geometry of the body of the break off roller l, the
rotating motion and the inclination of the rotary klln, as well as
especially from the frictional force between the break off roller
and the working surface it is disposed on, and also from the deposit
13 on, ancl lining 12 on, the interior wall of the kiln.
A further resultant component of movement occurs during the
unhindered movement of ~he break off roller l in the rotary kiln lO.
This component has a spiral direction.
Due to the aforementioned second component of movement, break
off rollers can overcome upward inclinations of rotary kilns.
Thereby it is possible to insert the break off roller into the open
rear end of a rotary kiln, by the conical tip of the roller facing
in the forward direction, and then conducting the removal operation
against the inclination of the rotary kiln.
The flow of broken out particles created during the break off
operation, is continuously removed in the direction of the
inclination of the rotary kiln, by means of the continuous rotation
thereof. During this, the break off roller l moves during the
guided working phase as much as possible in front of the flow of
broken out particles. The method of manufacture of the material,
the size, and the cutting edge of the tool can vastly differ while
the principle of operation of the break off roller remain unchanged.
Suitably, the body of the break off roller l is made of a conical,
robust and strongly articulated apparatus which is provided with
replaceable break off teeth 3, the stabilizing disc 5 having
radially adjustable elements, building elements that are based in a
protected manner, such as spring hanger, a universal coupling (not
shown), and a winch 9. The stabilizing disc 5 is mounted from the
end of the break off roller opposite to its conical end, and is
fi~ ly dttached to the roller. The transmlsslon OI $orces takes
place over robust, cylindrical bosses to enable taking up of the
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strong pushing and impact forces in the connection between the
stabilizing disc, the hody of the roller and the cutting disc 4.
These bosses are protrudingly welded to a stable flange disc (not
shown) of the roller body, and range in a locking relationship into
mating circular cavities on a flange disc. Connecting screws (not
shown) are inserted into the cylindrical bosses for establishing the
connection. The cylindrical bosses essentially take up the impact
and pushing forces. The sizes and shapes of the cutting disc 4, the
stabilizing disc 5 and the roller body are functionally harmonized
with each other. The roller body is connected with the replaceable
cutting teeth 3 of different size, for the breaking out process,
while the stabilizing disc has a stabilizing and supplemental
complementary function which can be advantageously employed for the
technologically advantageous guidance of the working and movement
relations of the break off roller. The construction of the break
off roller 1 involves a central, thick walled tube having stable
mainly radially arranged longitudinal ribs (not shown) welded on to
it, and generally four cutting discs 4 with teeth, which discs are
varied in size and strength.
At least one cutting disc 4 has a square shape and is
provided with a variety of suitably replaceable cutting teeth 3 of
various shapes and positions. The cutting disc is disposed on the
central guiding rod 2 outside of the center of gravity of the break
off roller, between its conical end and the attached cable 9. The
cutting teeth 3 rotate alony circular paths. Advantageously the
cutting teeth 3 are mounted in pairs, the constituent teeth of which
are of equal size within each pair. Suitably at least four cutting
teeth have the same size. Most suitably, the tips of the cutting
teeth 3 and the roll off teeth 3 form a square shaped cutting
disc and the squares formed from the various tips of the teeth are
offset with respect to each other in a manner that an irregular
octagon is formed. The cross sectional shape of the break off
roller 1 determines its effectiveness and its motion character-
istics. Thus, a roller cross section which is suitably provided
with corners provides rhymthmical impacts during rotation and this
significantly increases the destructive effect. Furthermore, in the
case of a cross section wicn COLI~r~, cne ~reaK orr roller can move
out from a bottom position in the cylinder and thus constantly free
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itself anew from a flow of particulate removed material. The effect
of the break off cylinder during the continuous rotation of the
rotary kiln can be decisively amplified due to the fact that the
deposit, and if desired the furnace lining, which has been shaken
and loosened by the break off roller, will lose its circular arch
structure and due to its own weight will collapse as the break off
roller 1 moves during the rotation to a maximum elevation and then
rolls back with an impact.
It is preferable that in all cases four cutting teeth 3 have
the same size. The shape of the cutting discs includes the feature
that the cutting teeth 3 are larger than the roll off teeth 3 .
They are arranged in pairs relative to each other. The roll off
teeth have a supporting function which influences the movement of
the break off roller 1. This influence is achieved through the fact
that the roll off teeth 3 are in a geometrical relationship with
the stabilizing disc 5 which cannot become snagged when these teeth
are in operatlon.
A small distance between cutting teeth 3 and the roll off
teeth 3 results in the case of a small distance, to a rolling off
movement of the break off roller, and when the distance is large,
then to an impacting of the teeth. This means that the cutting
tooth will impact on the bottom of the kiln as the break off roller
1 rolls back onto it.
According to another embodiment of the invention, the wedge
shaped cutting teeth are arranged on at least two cutting discs 4,
and the wedges of several of the cutting teeth are disposed at a
right angle to the longitudinal axis of the break off roller l. In
this case, the cutting teeth 3, during the movement of the break off
roller in the rotary kiln, are perpendicular to the inside of the
rotary kiln and, in relation to the transverse axis, they are
arranged also to coincide with the longitudinal axis.
A common feature of each cutting disc 4 is that the teeth 3
and 3 attached thereto, are arra~ged with their tips along a
circular path, oo~c~n~rioaly with the central axis of the roller.
The relative distances of the cutting discs 4, the sizes of the
29~ .
aforementioned circular paths of the tips o~ the teeth, ~s well as
the distribution and alignment of the teeth 3 and 3 are to be
made according to funckional requirements.
p
The operation of the break off roller 1 can be influenced by
the arrangement of the cutting discs 4 and the ~eeth 3 and 3 as
well as of the stabilizing disc 5 as follows. The principal
breaking off action of the break off roller 1 is oriented towards
the largest, the rearmost cutting disc 4. This results on one hand
from the position of the center of gravity, the impact lever arm of
the cutting disc ~ and its teeth, and on the other hand, from the
conical nature of the body of the break off roller. It is possible
that all teeth on all cutting discs 4 are biting into the deposit
under the break off roller, placing a bigger load on the drive, with
the result that the teeth dig deeper into the deposit and this
results in their breaking off more therefrom. By the use of the
stabilizing disc 5 all cutting teeth are bridged over and a smoother
running of the break off roll~r can be achieved. The use of the
stabilizing disc improves the movement over the base metal surface.
By means of the bridging over of the cutting teeth, no or only small
impacts are made onto the metal surface. Thus, the metal surface of
the interior of the rotary kiln and the cutting teeth can be better
protected against undue wear. It is a significant fact that the
movement of the break off roller 1 on the bare metal surface, in one
of its settings, without the use of the stabilizing disc, is
entirely different from its normal operating movement. The
considerable reduction of the frictional forces between the break
off roller and the bare metal surface in comparison to movement over
the deposit in the rotary kiln 10, results in that, in spite of the
rotation of the rotary kiln, the break off roller hardly rotates
therein. Thus the principal vertical output forces in the rotary
kiln 10 are supported to a greater extent by the flow of removed
matter 14, than the longitudinal motion components of the break off
roller 1 in the direction of its pointed end, and the break off
roller, therefore, moves in an uncontrolled fashion in the direction
of the rear end of the rotary kiln. The break off roller can be
properly adjusted by the use of the stabilizing disc and the
possibill~y or ilS ra~ia.L enlargement.
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A smooth rollable cross section can be achi~ved through
eleven radially ad~ustable polygon points that arP approximately
uniformly distribu~ed over the periphery of the stabilizing disc 5,
in contrast to the irregular octagon of the cutting disc 4. This
rollable cross sec~ion is disposed generally to the side, away from
the flow of broken off matter 14. In the case that it becomes
necessary to increase the friction between the stabilizing disc 5
and the metal hull of the rotary kiln 10, the radial adjusting
elements 6 of the stabilizing di6c 5 can be temporarily tipped with
contact elements 7, or the adjusting elements 6 can be provided in
the contact range, with suitable metals or metal alloys which have a
more favorable, i.e. higher coefficient of friction vis a vis steel.
The arrangement of the teeth 3, 3 on both smaller cutting
discs 4 depends geometrically from the arrangement of the larger
cutting discs 4. While the teeth 3 of both larger cutting discs 4
do the actual breaking out of matter, the teeth 3 of the two smaller
cutting discs 4 essentially serve to assure a sufficient bite of the
break off roller 1 in the deposit 13 and the lining 12 and in the
c~ntral part of the roller 1. The first cutting disc 4, as shown in
Fig. 2b of the preferred embodiment, is provided with four larger
cutting teeth 3 as well as four smaller roll off teeth 3 . As
further shown in Fig. 2b, the four large break off teeth 3 are
attached on alternate sides of the disc. This means that two teeth
3 are mounted with their wedges parallel, and two others with their
wedges perpendicular, to the longitudinal axis of the break off
roller 1. The arrangement of the teeth with their wedge
perpendicular to the longitudinal axis of the break off roller 1,
wear off the deposit and serve to tear up the arch of the kiln
lining, primarily at the starting area of the process, and behind
bracings. In contrast, the tooth arrangement wherein the wedge is
parallel to the longitudinal axis of the rotary kiln 10, serves
primarily for carrying on the break out process in the longitudinal
direction of the rotary kiln. The teeth 3 pry apart the rings of
the arch of the furnace lining in the direction of the longitudinal
axis of the rotary kiln, and this leads to their rapid collapse when
the impact takes place near to the breaking joint.
In addition to the nature of the material of the deposit, the
precise orientation of the four breaking off teeth 3 is important
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for determining ~heir useful life. This re~uires that when the
cylindrical roller body is til~ed, the teeth 3 should meet the
surface of the deposit as perpendicularly as possible. The need for
the four smaller roll off teeth 3 can be demonstrated from their
geometrical relationship to the stabilizing disc 5. The roll off
tooth 3 serves to lift the entire rolle~ body, especially in the
region of the stabilizing disc 5. This allows the realization of
the full impact strength of the teeth 3, without an intermediate
impact or rolling of the stabilizing disc 5 in any working position
of the break off roller 1. The second cutting disc 4 has, as the
first disc, eight teeth which are arranged on the second disc in a
manner similar to the first disc. Break off, and roll off teeth 3
and 3 are here of the same size as the roll off teeth 3 of the
first disc 4, due to the reduced effect. In contrast to the first
cutting disc 4, four break off teeth 3 are arranged with their
wedges being parallel to the longitudinal axis of the break off
roller 1, to support and ease the breakout process by the cutting
disc primarily in the direction of the longitudinal axis of the
kiln. The roll off ~eeth 3 are, in this embodiment, embedded in
the plane of the second cutting disc 4, and are turned about 45
with respect to the longitudinal axis.
The insertion of the break off roller 1 is concluded when its
rear end ranges into the rotary kiln lo at least to a depth of 0.~
to 1 meters. The starting speed of rotation of the rotary kiln 10
should be adjusted according to working experience, layer thickness
to be removed and the amount of loose mat~er in the kiln. The
deposit 13 should be removed first, at least to a full length of the
break off roller 1, before attempting to remove the first ring of
the furnace lining arch. In the case of break off roller insertions
when the furnace is hot, before the insertion of the break off
roller 1 into the rotary kiln 10, a possibly fat free and hemp free
rope, with thimbles on both sides and of about 10 meter length,
should be attached to the hook on the break off roller so that the
free end o~ the rope will be outside the rotary kiln and its
immediate hot vicinity, so that it can be connected to the rope of
the winch. The breaking out of the first rings of the furnace
~ arch takes place usually when tne Iorwar~ movement of the
break off roller 1 is slowed down by means of the rope, since the
lining at this point is usually under strong tension, especially
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~LX~956
towards the longitudinal direction of the kiln. In this phase o~
the operation, the first cutting disc 4 of the break off roller 1 is
to be run in a ~loating manner for about 0.2 to about 1 meter before
the rear edge of the rotary kiln 10, until that range i~ lightly
worked over. When the break out roller 1 is subsequently operated
at the rear end of the rotary kiln 10, it should not be able to be
displaced by the flow of loose broken material. Only when the break
out roller operates with controlled movements, should the initial
speed of the rotary kiln be increased. When the first three or four
rings of the furnace wall lining 12 to the next supporting ring are
completely broken out, then the guidance of the break out roller 1
should be adjusted for a strongly accelerated breaking out.
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