EP1833612A1 - Roller mill having a modular design - Google Patents

Abstract

The invention relates to a roller mill having a modular design. In order to make possible an increased nominal grinding capacity with a limited roll/oscillating lever mass and with a greater number of rolls, the supports are transferred toward the outside, and the oscillating lever pins, with regard to the transferred stands, are arranged in an off-center and radially inward manner between the grinding plate and the support.

Description

Roller mill in modular design

The invention relates to a roller mill according to the preamble of claim 1.

Roller mills in modular design can be constructed, for example, according to the LOESCHE system. In these Wälzmühlen a power unit is used as a building block, which consists of a stand with a rocker arm bearing for a rocker arm and guided therein grinding roller, a rocker arm seal against the mill housing and a hydropneumatic suspension system (DE 196 03 655 Al).

An advantage of the modular construction is a mill construction which can be realized with a relatively low outlay in accordance with the required grinding capacity.

In principle, roller mills with two, three, four or more, rolling on a rotating Mahlschüs'sel grinding rollers are known. Modular air flow roller mills according to the Loesche system have hitherto been implemented in arrangements with two, three and four rollers. The largest Loech roller mill for the cement industry to date has a nominal grinding capacity of 840 t / h for cement raw material. In this mill, the weight of a grinding roller with rocker arm is about 90 t.

There is now a demand for even higher nominal product rates, especially in the cement industry. To realize basically there is the possibility to arrange larger grinding rolls, for example in a 4-roll mill.

However, larger grinding rolls have a significantly higher roll / rocker mass, which results in an increase in machine vibration during the grinding operation as well as higher costs of the grinding rolls and the associated power transmission systems. Other disadvantages are the relatively large footprint in mounting and dismounting of the grinding rollers and the necessary heavy lifting equipment.

An increase in the capacity of a roller mill can in principle also be achieved with a larger number of rolls, for example with five or six grinding rolls. This means a corresponding increase in the number of stands and a smaller distance between the stands.

However, a higher nominal / grinding power also requires the supply of higher gas flows and thus a larger annular channel or gas channels with a larger diameter. For a higher number of stands and adequately sized gas ducts there is not enough room at the circumference of the mill. Also, the installation space for assembly and disassembly of the mill gear and the grinding bowl storage would not be feasible.

The invention has for its object to provide a roller mill in modular design, in which while maintaining the advantages of the modular design of a 4-roll mill with a larger number of grinding rollers a significant increase in grinding nominal power while sufficient space for installation and maintenance is guaranteed . According to the invention the object is achieved by the features of claim 1. Advantageous and advantageous embodiments are contained in the subclaims and in the description of the figures.

A basic idea of the invention can be seen in designing the position of the oscillating lever axes with respect to the respectively associated stand in such a way that the stator and grinding roller oscillating lever construction as well as the grinding table can be maintained and, at the same time, sufficient installation space for the mill gear or for the mill gear Mahlschüssellagerung and also for the annular channel and the gas channels below the grinding bowl are present.

For a roller mill according to the invention, for example a 6-roller mill, grinding rollers with a limited grinding roller / oscillating lever mass and a grinding plate are used, which are known, for example, from 4-roller mills. The stands can advantageously also correspond to the known stands. Excluded is the arrangement of the rocker arm axes in or on the uprights.

According to the invention, the stands are arranged to realize a sufficiently large installation space for the transmission and a sufficient space for the annular channel and the gas channels of the gas streams at a greater radial distance from the grinding bowl or to the mill center, the position of the rocker axes to the grinding bowl or but the mill center is not changed.

Based on the respectively associated stand, the oscillating lever axis is in a new position. The oscillating lever axis is no longer arranged as in the known roller mill within the stator profile, for example on the longitudinal axis of the stator. According to the invention, each oscillating lever axis is formed outside of the stator and is located, relative to a circular ring formed by the uprights, radially inward in the direction of the grinding table or mill center.

The arrangement of the rocker axles for the grinding rollers outside the stand means at the same time that the rocker axes are no longer provided within the floor plans of the stand.

According to the invention, therefore, the rocker shaft is no longer on the vertical column axis, and the stands are no longer substantially cylindrical structures with a generally rectangular cross-section, but have an upper portion with a bearing part for the rocker shaft, which for example, a "bent" and pointing towards the mill center area.

According to the invention, the bearing part for the rocker arm axis can be integrated into the uprights and manufactured with them, which can be advantageous, for example, in the case of steel uprights. The bearing part is then a projecting towards the mill center part which receives the rocker arm axis.

The stand can also be designed as a concrete stand. It is then advisable to arrange a bearing block at the top of the stand as a casting and to provide the bearing block with a radially inwardly projecting towards grinding plate bearing part.

The main advantages of the roller mill according to the invention are that an increase in the nominal grinding capacity by arranging several grinding rollers around a grinding table can be achieved, the known and proven roller / rocker arm construction can be used and also the grinding table can be substantially maintained. By only the stands are displaced radially outward and the arrangement or positioning of the bearing for the oscillating lever axis of the stator with respect to the mill center or the grinding table is not changed, relatively low construction and investment costs for mills different grinding performance required.

When using a bearing block, it is expedient to provide a fastening part, with which the bearing block can be attached to the stand, and to arrange the bearing part for the swing lever axis. For example, the bearing part may be in the form of two cheeks spaced apart from each other.

In the stator rocker arm axle construction according to the invention advantageous measures for stiffening can be provided. For example, in the upper region of the uprights and the radially inwardly staggered oscillating lever axes, intermediate elements can be arranged which fill the space between the uprights and oscillating lever axes and form a torsion-resistant rim or ring.

The intermediate elements may extend from the radially outer edge of the stand or the bearing blocks to the mill housing or to the radially inner end of the bearing part and be formed almost circular ring segment-like.

The invention will be further explained below with reference to a drawing; in this show in a highly schematized way 1 shows a rolling mill according to the invention in modular design, but without mill housing and classifier.

2 shows a cross section of the roller mill according to the invention in the region of the stator and the mill gear;

3 is a side view of a stand with swing lever axis.

4 is a view according to arrow IV in FIG. 3 and

5 is a plan view according to arrow V in FIG. Third

In Fig. 1 is a perspective view of a roller mill, but only the components essential to the present invention are shown. For better clarity, it was decided not to display the entire mill housing with integrated sifter.

In the roller mill according to FIG. 1 and 2 is a modular 6-roller mill. There are six grinding rollers 2 arranged around a rotating grinding table 3. Each grinding roller 2 is guided in a rocking lever 4 and mounted pivotably about a rocking lever axis 5 and supported on a stand 7 via the rocking lever axis 5.

For swinging the grinding rollers 2 and the rocker arm 4 of the in Fig. 1 shown in Fig. 1 in a swung out of the mill housing 16 position (not shown) openings 17 are provided in the mill housing 16. The openings 17 are provided to form a gas-tight mill housing 16 with corresponding covers (not shown). Each grinding roller 2 with rocker arm 4 and horizontal rocker shaft 5 has a hydropneumatic suspension 18, which is anchored to the stator 7 in a mill foundation (not shown).

In the mill center, the transmission 6 and the mill drive are arranged on a transmission foundation 19 (see also FIG. 2). Furthermore, box-shaped gas channels 20 are arranged between the uprights 7, through which the required gas flows are fed to the mill (not shown) on the circumference of the grinding table 3 in the grinding chamber and the sufficiently comminuted millbase for classifier (not shown ) to wear.

In the embodiment shown in Fig. 1, the rocker axes 5 of the grinding rollers 2 are mounted in a bearing block 10. From the enlarged representations of a stator 7 in FIGS. 3 to 5, arrangement and design of the bearing block 10 are apparent. According to the invention, the oscillating lever axis 5 is no longer above the stator 7 or on the longitudinal axis 14 of the stator, but next to or in a radially inwardly offset in the direction of the grinding table 3 position.

At the upper region of the stator 7, the bearing block 10 is fastened with a fastening part 11. For this purpose, the fastening part 11 has a complementary design to the upper region of the uprights 7. Laterally on the fastening part 11 and directed away from this and projecting obliquely upwards, a bearing part 12 in the form of two cheeks 13 is provided, which serve for the mounting of the oscillating lever axis 5.

By the swing lever axis 5 is no longer in the area of the stator 7, namely within the outline of the stator 7, but outside, and, seen in the operating position shown in FIG. 1, radially inwardly between the stator 7 and grinding plate 3 is arranged, an arrangement of more than four grinding roller stand units is possible around a grinding table 3 with a relatively low effort. In this case, grinding rollers 2 and rocker arm 4 with limited roller / rocker arm masses and grinding table 3 can advantageously be used by a grinding roller with fewer grinding rollers, in particular by a 4-roller mill.

In order to ensure the necessary distance between the uprights 7 for the required arrangement of sufficiently sized gas ducts 20 and also for the assembly and disassembly of the gear 6 positioned in the center of the mill, the uprights 7 are outwardly compared to a 4-roll mill relocated. In order not to change the rocking lever axis 5 with respect to the rocking lever 4 and the grinding roller 2 and towards the mill center or mill axis, the position of the rocking lever axis 5 with respect to the uprights 7 has been changed. In the examples shown in the figures, an eccentric arrangement of the oscillating lever axis 5 relative to the uprights 7 is achieved by a corresponding design of the separate bearing block 10.

In principle, it is also possible to integrate the radially outwardly projecting bearing part 12 with the outside of the stand 7 to be arranged rocking lever axis 5 in the stator 7. For example, this can be achieved in steel stands by a corresponding angled or bent upper portion.

In the upper region of the uprights 7 and at least adjacent to the fastening parts 11 of the bearing blocks 10, intermediate elements 15 are arranged to stiffen and form a torsionally rigid ring. In Fig. 2 is a highly schematic representation of the arrangement of the stator 7 of the mill shown in FIG. 1 in its lower region. By the gear 6 is shown in the center of the mill with a geared foundation 19, it is clear that the required expansion space 21 between two adjacent uprights 7 is present.

In the Figs. 3 to 5 are the in Fig. 1 shown stand 7 shown enlarged. They illustrate the eccentric or outside the outline of the stator 7 positioned oscillating lever axis 5. This training or positioning of the oscillating lever axis 5 between the grinding table 3 and the mill housing 16 and the respective stator 7 is without substantial change of the grinding table 3, the grinding rollers. 2 achieved with rocker arm 4 and the lower portions of the stator 7 that more grinding rollers 2, in particular six grinding rollers 2 can be arranged and increased mill performance can be achieved.

Claims

1. Roller mill in modular design with grinding rollers (2), which roll on a rotating grinding table (3) and each with a rocking lever (3) about a rocking lever axis (5) are pivotally mounted, with a gear (6) for the grinding table (3) and with uprights (7), which for separate support of the grinding rollers (2) to form a construction space (21) for the transmission (6) arranged around the grinding plate (3) and for receiving the rocker axes (5) of the grinding rollers (2) are, characterized in that the oscillating lever axes (5) of the grinding rollers (2) outside the floor plan of the stator (7) and offset radially inwardly toward the grinding table (3) on the uprights (7) are arranged. 2. Roller mill according to claim 1, characterized in that for receiving the oscillating lever axis (5) at the upper end of the stator (7) a bearing block (10) is arranged, which has a fixing part (11) for attachment to the stator (7) and a Bearing part (12) for the oscillating lever axis (5), and that the bearing part (12) laterally on the fastening part (11) and, in the mounted state of the bearing block (10) on the stator (7), in the direction of grinding plate (3) is cantilevered , 3. Roller mill according to claim 1 or 2, characterized in that the bearing block (10) has a fastening part (11) which is complementary to the upper end of the stator (7) is formed, and that the bearing part in the form of two obliquely upward Cheeks (13) is formed, which for receiving the rocker arm (4) are spaced from each other. 4. Roller mill according to one of the preceding claims, characterized in that for the arrangement of more than four grinding rollers (2), in particular of six grinding rollers (2), and the associated stands (7) to a grinding plate (3) of constant size and to maintain of the expansion space (21) for the transmission (6) only the stator (7) adjusted radially outward and according to the formed radial distance between the retained grinding rollers (2) with rocker arms (4) and rocker axes (5) correspondingly dimensioned, radially in between the grinding plate (3) and the uprights (7) arranged bearing parts (12) with the swing lever axis (5) are provided. 5. Roller mill according to one of the preceding claims, characterized in that between the uprights (7) with the radially inwardly offset bearing parts (12) for the rocker axes (5) intermediate elements (15) are arranged for stiffening. 6. Roller mill according to claim 5, characterized in that the intermediate elements (15) are arranged in the upper region of the uprights (7), in particular laterally adjacent to the bearing blocks (10), and form a torsion-resistant bandage. 7. Roller mill according to one of the preceding claims, characterized in that e e e c e s e n e that the bearing parts (12) are integrated with oscillating lever axis (5) in the stator (7).