|Title of Invention||
ROLLER MILL HAVING A MODULAR CONSTRUCTION
|Abstract||The invention relates to a roller mill having a modular construction. In order to permit an increased rated grinding capacity with a limited roller/rocking lever mass and a larger number of rollers, the standards are displaced outwards and the rocking lever axes, relative to the displaced standards, are positioned eccentrically and radially inwards between the grinding table and standards.|
|Full Text||English translation of the filed PCT-Application
ROLLER MILL HAVING A MODULAR CONSTRUCTION
The invention relates to a roller mill according to the preamble of claim 1.
Roller mills having a modular construction can e.g. be constructed according to the
LOESCHE system. In such roller mills use is made of a power unit in the form of a module
and which comprises a support or standard with a rocking lever bearing for a rocking lever
and a grinding roller guided therein, a rocking lever seal with respect to the mill housing
and a hydropneumatic suspension system (DE 196 03 655 A1).
An advantage of the modular construction is a mill structure implementable at relatively
low cost and in accordance with the in each case required grinding capacity.
On principle, roller mills with two, three, four or more grinding rollers rolling on a rotary
grinding pan are known. Air-swept roller mills having a modular construction according to
the Loesche system have hitherto been implemented in arrangements with two, three and
four rollers. The hitherto largest Loesche roller mill for the cement industry has a rated
grinding capacity of 840 t/h for cement raw material. In this mill the weight of a grinding
roller with rocking lever is approximately 90 t.
In the meantime, particularly in the cement industry, there has been a need for even
higher rated production rates. To implement this it is in principle possible to place larger
grinding rollers, e.g. in a 4-roller mill.
However, larger grinding rollers have a much higher roller/rocking lever mass, which leads
to an increase in machine vibrations during milling operation and to higher costs for the
grinding rollers and the associated power transmission systems. Further disadvantages
are the relatively large space requirements on installing and dismantling the grinding
rollers and the heavy lifting equipment necessary for this.
In principle, it is also possible to increase the capacity of a roller mill by using a larger
number of rollers, e.g. five or six grinding rollers. This means a corresponding increase in
the number of standards and a smaller distance between the standards.
However, a higher rated/grinding capacity also requires the supply of higher gas flows and
therefore a larger annular duct or gas ducts with a larger diameter. For a higher number of
standards and adequately dimensioned gas ducts sufficient space is not available on the
mill circumference. It would also be impossible to implement the necessary building area
for installation and dismantling of the mill gearing and the grinding pan bearing.
The object of the invention is to provide a roller mill having a modular construction in
which, whilst retaining the advantages of the modular construction of a 4-roller mill, with a
larger number of grinding rollers it is possible to ensure a significant increase in the rated
grinding capacity whilst simultaneously providing adequate space for installation and
According to the invention this object is achieved through the features of claim 1.
Appropriate and advantageous developments appear in the subclaims and the specific
description relative to the drawings.
It is a fundamental idea of the invention to make the position of the rocking lever axes with
respect to the in each case associated standards such that the standard and grinding
roller-rocking lever construction, as well as the grinding table or pan can be retained,
whilst simultaneously providing adequate building space for the mill gear or the grinding
pan bearing and also for the annular duct and gas ducts below the grinding pan.
For an inventive roller mill, e.g. a 6-roller mill, use is made of grinding rollers with a limited
grinding roller/rocking lever mass and a grinding table, which are e.g. known from 4-roller
mills. The standards advantageously also correspond to the known standards. The
exception to this is the arrangement of the rocking lever axes in or on the standards.
For implementing an adequately large building area for the gearing and an adequate
space for the annular duct and the gas ducts for the gas flows, according to the invention
the standards are placed with a greater radial spacing from the grinding pan or the mill
centre, but there is no change to the position of the rocking lever axes with respect to the
grinding pan or mill centre.
Relative to the in each case associated standard, the rocking lever axis is in a new
position. Unlike in the known roller mills the rocking lever axis is no longer placed within
the standard profile, e.g. on the longitudinal axis of the standard.
According to the invention each rocking lever axis is located outside the standard and,
with respect to an annulus formed by the standards, is radially inwards in the direction of
the grinding table or mill centre.
The arrangement of the rocking lever axes for the grinding rollers outside the standards
simultaneously means that the rocking lever axes are no longer located within the plan
views of the standards.
Thus, according to the invention the rocking lever axis is no longer on the vertical standard
axis and the standards are no longer substantially cylindrical constructions with a usually
rectangular cross-section and instead have an upper area with a bearing part for the
rocking lever axis, which is e.g. a "broken off or bent area directed towards the mill
According to the invention the bearing part for the rocking lever axis can be integrated into
the standards and manufactured therewith, which can e.g. be advantageous in the case of
steel standards. The bearing part is then a part which projects in the mill centre direction
and receives the rocking lever axis.
The standards can also be constructed as concrete standards. It is then advantageous to
provide on the upper area of the standards a bearing block in the form of a casting and to
provide the bearing block with a bearing part projecting radially inwards in the grinding
The essential advantages of the inventive roller mill are that the rated grinding capacity
can be increased by the placing of several grinding rollers around a grinding table, the
known and proven roller/rocking lever construction being usable and the grinding table
can also essentially be retained. As only the standards are displaced radially outwards
and the arrangement or positioning of the bearing for the rocking lever axis of the
standards with respect to the mill centre or grinding table is unchanged, relatively limited
construction and investment costs are needed for mills having different grinding
When using a bearing block it is appropriate to provide a fixing part with which the bearing
block can be fixed to the standard and to place thereon the bearing part for the rocking
lever axis. For example, the bearing part can be constructed in the form of two spaced
flanks or side-pieces.
In the case of the inventive standard-rocking lever axis construction advantageously
rigidifying measures can be provided. For example, in the upper area of the standards and
the radially inwardly displaced rocking lever axes intermediate elements can be placed,
which fill the spacing between the standards and the rocking lever axes and form a
torsionally resistant ring or rim.
The intermediate elements can extend from the radially outer edge of the standards or
also the bearing blocks up to the mill housing or up to the radially inner end of the bearing
part and have an almost circular ring segmental construction.
The invention is described in greater detail hereinafter relative to the diagrammatic
drawings and wherein show:
Fig. 1 An inventive roller mill with a modular construction, but without the mill housing and
Fig. 1 A cross-section through the inventive roller mill in the vicinity of the standards and
the mill gearing.
Fig. 3 A side view of a standard with rocking lever axis.
Fig. 4 A view according to arrow IV in fig. 3.
Fig. 5 A plan view according to arrow V in fig. 3.
Fig. 1 shows a perspective view of a roller mill, but only showing the components essential
for the present invention. Thus, in order not to overburden representation the complete
mill housing with integrated classifier is not shown.
The roller mill according to figs. 1 and 2 is a 6-rolIer mill having a modular construction.
Six grinding rollers 2 are placed around a rotary grinding table 3. Each grinding roller 2 is
guided in a rocking lever 4 and pivotably mounted about a rocking lever axis 5 and
supported by means of said rocking lever axis on a standard 7.
For pivoting out the grinding rollers 2 and rocking lever 4 from the grinding position shown
in fig. 1 into a position (not shown) pivoted out of the mill housing 16, openings 17 are
provided in said mill housing 16. The openings 17 are provided for forming a gastight mill
housing 16 with corresponding covers (not shown).
Each grinding roller 2 with rocking lever 4 and horizontal rocking lever axis 5 has a
hydropneumatic suspension 18, which is anchored to the standard 7 in a mill foundation
In the mill centre, the gearing 6 and the mill drive (cf. also fig. 2) are positioned on a
gearing foundation 19. Furthermore, there are box-like gas ducts 20 between the
standards 7 through which the necessary gas flows are supplied to the mill in order to
pass through the blade ring (not shown) on the circumference of the grinding table 3 into
the grinding area and carry the adequately ground grinding material to the classifier (not
In the embodiment shown in fig. 1 the rocking lever axes 5 of the grinding rollers 2 are
mounted in a bearing block 10. The larger scale representations of a standard 7 in figs. 3
to 5 show the arrangement and construction of the bearing block 10. According to the
invention the rocking lever axis 5 is no longer located above the standard 7 or on the
longitudinal axis 14 of said standard, but instead is alongside the same and in a position
displaced radially inwards towards the grinding table 3.
The bearing block 10 is fixed with a fixing part 11 to the upper area of the standards 7. To
this end the fixing part 11 has a construction complementary to the upper area of the
standards 7. Laterally on the fixing part 11 and directed away from the same and in
upwardly sloping and projecting manner is provided a bearing part 12 in the form of two
flanks 13 used for mounting the rocking lever axis 5.
As the rocking lever axis 5 is no longer located in the vicinity of the standards 7, namely
within the plan view of the standards 7, but instead outside the same and, in the operating
position according to fig. 1, radially inwards between standard 7 and grinding table 3, an
arrangement of more than four grinding roller-standard units around a grinding table 3 is
possible at a relatively low cost. Advantageously grinding rollers 2 and rocking levers 4
with limited rollers/rocking lever masses and grinding tables 3 of a roller mill with fewer
grinding rollers, particularly of a 4-roller mill, can be used.
In order to ensure the necessary spacing between the standards 7 for the requisite
arrangement of adequately dimensioned gas ducts 20 and also for installation and
dismantling of the gearing 6 positioned in the centre of the mill, compared with a 4-roller
mill the standards 7 are displaced outwards. In order not to modify the rocking lever axis 5
with respect to the rocking lever 4 and grinding roller 2 and also in the direction of the mill
centre or mill axis, the position of the rocking lever axis 5 with respect to the standards 7
was modified. In the example shown in the drawings there is an eccentric arrangement of
the rocking lever axis 5 relative to the standards 7 as a result of a corresponding
construction of the separate bearing block 10.
It is fundamentally also possible to integrate the radially inwardly projecting bearing part
12 with the rocking lever axis 5 to be located outside the standards 7 into said standards
7. For example, this can be achieved in the case of steel standards by a correspondingly
bent or angled upper area.
In the upper area of the standards 7 and at least adjacent to the fixing parts 11 of the
bearing blocks 10, intermediate elements 15 are placed for rigidification and the
construction of a torsionally resistant ring.
Fig. 2 shows in highly diagrammatic form the arrangement of the mill standards 7
according to fig. 1 in the lower area thereof. Through showing the gearing 6 in the centre
of the mill with a gearing foundation 19, it is clear that the necessary building area 21
exists between two adjacent standards 7.
The standards 7 shown in fig. 1 are represented on a larger scale in figs. 3 to 5 and they
make clear the eccentric position of the rocking lever axis 5 outside the plan view of the
standards 7. As a result of this construction or positioning of the rocking lever axis 5
between the grinding table 3 or the mill housing 16 and the given standard 7, without any
significant change of the grinding table 3, grinding rollers 2 with rocking lever 4 and lower
areas of the standards 7, it is achieved that more and in particular six grinding rollers 2
can be provided and an increased grinding capacity can be obtained.
1. Roller mill having a modular construction
with grinding rollers (2) rolling on a rotary grinding table (3) and in each case
pivotably mounted about a rocking lever axis (5) with a rocking lever (4), having a
gearing (6) for the grinding table (3) and with standards (7) which, for the separate
supporting of the grinding rollers (2) and accompanied by the formation of an
building area (21) for the gearing (6), are arranged around the grinding table (3)
and constructed for receiving the rocking lever axes (5) of the grinding rollers (2),
characterized in that
the rocking lever axes (5) of the grinding rollers (2) are placed outside the plan view
of the standards (7) and are displaced radially inwards towards the grinding table
(3) on the standards (7).
2. Roller mill according to claim 1,
characterized in that
for receiving the rocking lever axis (5), on the upper end of the standards (7) is
placed a bearing block (10), which has a fixing part (11) for fixing to the standard
(7) and a bearing part (12) for the rocking lever axis (5), and that the bearing part
(12) is positioned laterally on the fixing part (11) and, in the installed state of the
bearing block (10) on the standard (7), projects towards the grinding table (3).
3. Roller mill according to claim 1 or 2,
characterized in that
the bearing block (10) has a fixing part (11) constructed in complementary manner
to the upper end of the standards (7) and that the bearing part is in the form of two
upwardly sloping flanks (13), which are spaced from one another for receiving the
rocking lever (4).
4. Roller mill according to one of the preceding claims,
characterized in that
for placing of more than four grinding rollers (2), particularly six grinding rollers (2),
and the associated standards (7) around a grinding table (3) of constant size and
for maintaining the building area (21) for the gearing (6), only the standards (7) are
displaced radially outwards and corresponding to the resulting radial spacing
between the retained grinding rollers (2) with rocking levers (4) and rocking lever
axes (5), correspondingly dimensioned bearing parts (12) positioned radially
inwards between the grinding table (3) and the standards (7) with rocking lever axis
(5) are provided.
5. Roller mill according to one of the preceding claims,
characterized in that
intermediate elements (15) are placed for rigidification purposes between the
standards (7) with the radially inwardly displaced bearing parts (12) for the rocking
lever axes (5).
6. Roller mill according to claim 5,
characterized in that
the intermediate elements (15) are located in the upper area of standards (7),
particularly laterally adjacent on the bearing blocks (10), and form a torsionally
7. Roller mill according to one of the preceding claims,
characterized in that
the bearing parts (12) are integrated with the rocking lever axis (5) into the
The invention relates to a roller mill having a modular construction.
In order to permit an increased rated grinding capacity with a limited roller/rocking lever
mass and a larger number of rollers, the standards are displaced outwards and the
rocking lever axes, relative to the displaced standards, are positioned eccentrically and
radially inwards between the grinding table and standards.
|Indian Patent Application Number||1359/KOLNP/2007|
|PG Journal Number||22/2011|
|Date of Filing||18-Apr-2007|
|Name of Patentee||LOESCHE GMBH|
|Applicant Address||HANSAALLEE 243, 40507 DUESSELDORF|
|PCT International Classification Number||B02C 15/04|
|PCT International Application Number||PCT/EP2005/012301|
|PCT International Filing date||2005-11-16|