WO2016116189A1

WO2016116189A1 - Coaxial mill and feed unit for a mill

Info

Publication number: WO2016116189A1
Application number: PCT/EP2015/076828
Authority: WO
Inventors: Martin Gross
Original assignee: Robert Bosch Gmbh
Priority date: 2015-01-21
Filing date: 2015-11-17
Publication date: 2016-07-28
Also published as: CN107206391B; EP3247499A1; DE102015200924A1; CN107206391A; CA2970039C; CA2970039A1; EP3247499B1

Abstract

The invention relates to a mill (1) and to a feed unit (2) for a mill (1). The feed unit (2) comprises: a first interface (3) for holding a rotor (4) of a grinder (46), a second interface (5) for holding a stator (6) of the grinder (46), a feed pipe (7), which is arranged to feed material for grinding (8) into the grinder (46), and an annular rotary bearing (9) on the feed pipe (7) which is disposed in such a way that, in operation, material for grinding (8) enters the grinder (46) through the rotary bearing (9).

Description

Description title

Coaxial mill and feeding unit for a mill prior art

The present invention relates to a mill and a feed unit for a mill. In particular, the present invention relates to a coaxial mill in which set-up and maintenance operations can be carried out in a particularly simple and time-saving manner.

In current processes for the production of granules, mills are regularly used to eliminate irregularities in the particle size distribution with respect to maximum grain size and / or to structure wet granules. As a result, follow-up processes can be optimized or made possible in the first place. By way of example, these are for dry granules

Grain size reduction for the tableting process or

Grain size reduction for wet granules in order to dry them faster or to give this structure for improving the drying, flowability and / or meterability.

The mills known in the art are grown as ancillary equipment to machinery and apparatus (e.g., manufacturing and / or production technology) for producing granules. Since these machines were designed and built for closed batch operation, they are provided with lockable emptying and filling openings. These apparatuses are designed and operated in such a way that the risks of explosion are minimized and their effects do not pose a risk to the persons in the environment of the machines due to the material properties and the process requirements.

US Pat. No. 5,405,094 shows a multi-stage mill in which two sieving units are driven by means of rotationally driven stirring elements for comminuting regrind be used. The stirring elements are driven by a shaft, which is supplied by means of a belt with kinetic energy.

No. 5,863,004 shows a mill in which a stirring element arranged on a sieve element is arranged downstream from one

Drive unit is moved to press ground material through the sieve unit.

The mills known in the prior art is common that in case of a required replacement of the screening units or in case of opening of the grinder to remove clogging large parts of the mill must be taken apart, which is time-consuming and therefore expensive. Sometimes an increased set-up time can adversely affect the process reliability of an entire system. Sometimes mills require the

Prior art additional consoles and sliding or

Swivel devices to bring the mills into working position, to equip (e.g., screen change, rotor screen tool), to clean and to maintain. In addition, in the known solutions, the material to be ground (product) flows from above at a flow direction upstream mill drive from above the drive rod, which therefore hinders the product flow on the input side. In addition, in solutions with a drive with a drive downstream in the flow direction, the product drain down is obstructed by the bevel gear and sieve and rotor can be maintained or changed only from above (after disassembly of the product supply). The same applies to the removal process of blockage of the mill and for cleaning and inspection operations. It is therefore an object of the present invention to alleviate or overcome the aforementioned drawbacks.

Disclosure of the invention

The object identified above is achieved by a mill and a feed unit for a mill according to the invention. The feed unit is used to supply regrind in the direction of the grinder. According to the invention, a first interface for holding a rotor of a grinder is provided. The rotor forms the moving component of the grinder. A second interface is provided for mounting a stator of the grinder, which in

Cooperation with the rotor causes the comminution of the ground material by a relative movement between the rotor and the stator. Next is one Supply pipe provided, which is adapted to guide ground material in the grinder. According to the invention, an annular rotary bearing is provided on the feed tube, which allows relative rotation between the feed tube and another component of the mill. Due to the ring shape, the rotary bearing can be arranged on the supply pipe such that in operation

Grist passes through the rotary bearing in the grinder. In other words, the annular rotary bearing encloses at least part of a free pipe cross-section of the feed pipe so that the material to be ground is conveyed through the "eye" of the rotary bearing and through the feed pipe the geometry of the grinder as well as its attachment and accessibility for set-up and maintenance purposes are made extremely low, so that the downtime of a mill equipped according to the invention can be reduced.

The dependent claims show preferred developments of the invention.

The rotary bearing can be configured for example as a rolling bearing or as a sliding bearing. In other words, rolling elements between an inner and an outer or an upper and a lower ring of the

Roll down the bearing to ensure a particularly low frictional force at high speeds

to allow transferring compressive forces. Such a roller bearing can be configured as a roller bearing or as a ball bearing. The plain bearing can

Having particularly low coefficient of sliding friction (e.g., nylon and metal), the sliding friction coefficient can be further reduced by the use of lubricants.

The rotary bearing can be arranged, for example, between the first interface for mounting the rotor of the grinder and the feed pipe. In this way, the supply tube can be stored statically and the rotor around the

Supply tube to be arranged rotating.

Alternatively, the supply pipe can be designed to rotate automatically and be connected in a rotationally fixed manner to the rotor of the grinding mechanism. In this case, the annular rotary bearing between the feed tube and a fixed part of the mill or other fixed structure (for example, a upstream supply pipe) may be arranged. Also in this case, the material to be ground is transported through the rotary bearing in the grinder.

Alternatively or additionally, the rotary bearing between the second

Be arranged interface for holding the stator of the grinder and the supply pipe. Also in this case, the supply pipe of the

Feed unit according to the invention perform a rotational movement relative to the stator of the grinder, while it is rotatably mounted on the rotor of the grinder.

The second interface for mounting the stator of the grinder can be arranged mechanically non-rotatable and coaxial with a stator of an electric machine, via which the grinder (for example, electrically) is driven. In this way, the power transmission can be omitted by means of a belt or a chain, whereby energy losses and additional space for power transmission can be saved.

The first interface for holding the rotor of the grinder can be connected via a belt drive or a chain with a rotor of an electric machine, whose shaft is arranged substantially parallel to the axis of the grinder. As an alternative to an electric machine, a hydraulic or pneumatic drive mode for the machine can be provided. In this way, the actual supply unit can be designed to be particularly compact and volume-optimized, while the electric drive can be arranged at a different position in the production space. In this way, a maintenance or replacement of the electrical machine can be favored.

The supply pipe can have a channel which extends in the axial direction, by means of which a fluid can be conducted to outlets arranged in the region of the grinding mechanism. For example, the feed pipe can be designed as a double-walled hollow wall pipe, so that the fluid can be guided between an inner and an outer wall in the grinder. The fluid may include, for example, a gas and / or a liquid. In this way, a cleaning of the inventively equipped mill simplified by no removal of parts of the supply unit is required for rinsing. Alternatively or additionally, a fluid can also be introduced between the feed tube and the first interface for holding the rotor of the grinding mechanism, for which purpose a connection can be arranged in a front region of the feed unit with respect to the ground material flow. Here, if necessary, a fluid supply (a hose or similar) can be connected or a permanently connected hose can be supplied with pressurized fluid. In this way it can be prevented, for example, that grinding stock penetrates between the feed tube and a rotating part of the feed unit and leads to contamination or mechanical problems.

Additionally or alternatively, mixing, dispersing, loosening,

Conveyor elements are attached to the rotor / stator system in the feed unit, e.g. To break lumps of raw material or product bridges or to improve the product flow (regrind).

Optionally, fluid (e.g., a gas) may be employed to assist, for example, product transport when using the mill in pneumatic conveying.

Further, optionally, a fluid (e.g., an inert gas) may be used to, for example, aerate the mill interior to reduce the oxygen content such that an explosion hazard can be reduced.

More preferably, a fluid (e.g., a liquid) may be used to wet the product to be ground before it is fed into the grinder. This can, for example, the flow capabilities and / or the life of the

Improve grinder.

According to a second aspect of the present invention, a mill is proposed which, for example, as a process mill in the

Production technology can be designed. The mill may alternatively or additionally be configured as a wet mill or as a wet and dry mill for processing granules. In other words, the mill may be configured to process three phases (solid, liquid and gas). It comprises a rotor of a grinder and a stator of a grinder, which effect a predetermined comminution of material to be ground in cooperation with each other. The rotor is at the first interface and the stator is arranged at the second interface of a supply unit, as have been described in detail in connection with the first-mentioned aspect of the invention. Accordingly, a mill according to the invention by mounting a rotor and a stator of a grinder on a

constructed supply unit according to the invention. Of course, additional parts may be included (e.g., for closing a feed port for regrind and / or closing a reject port for regrind and / or other elements (e.g., dispersing elements for breaking lumps, product bridges) or conveying elements.

The first interface for holding the rotor of the grinder, for example, allow a screw connection between the rotor and another component of the supply unit. Alternatively or additionally, a bayonet closure may be provided between the rotor and the additional component of the supply unit. Alternatively or additionally, a snap / locking connection, a clamping connection or even an opening of the

Feed unit circumferential thread be provided in the rotor of the grinder to allow a reversible, yet fixed mounting of the rotor to the feed unit. The same applies to the stator of the grinder and its connection to a second component of the feed unit according to the invention.

The rotor and the stator of the grinder can be provided as correspondingly designed sieve elements with openings and / or cutting. By way of example, its envelope surface can be configured in the shape of a truncated cone. Due to the assembly according to the invention in particular the possibility arises to use the entire vertically oriented to the longitudinal axis of the feed tube screen surface of the grinder also for the comminution, since no drive shaft o.ä. must be provided.

Brief description of the drawings

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawings:

Figure 1 is a schematic side view of an embodiment of a mill according to the invention equipped with a Embodiment of a supply unit designed according to the invention; a schematic side view of an alternative

Embodiment of a mill according to the invention equipped with an alternative embodiment of an inventively designed supply unit; a schematic side view of an alternative

Embodiment of a mill according to the invention equipped with an alternative embodiment of an inventively designed supply unit, comprising a belt drive and a separate electric machine for driving the mill; a schematic side view of an alternative

Embodiment of a mill according to the invention equipped with an alternative embodiment of an inventively designed supply unit; and a detailed view illustrating possible embodiments of the first and second interfaces as well as seals and fluid channels. Embodiments of the invention FIG. 1 shows an exemplary embodiment of a mill 1 according to the invention, which has a feed unit 2 according to the invention. The supply unit 2 has a first bayonet closure 3 as the first interface for mounting a rotor 4 of a grinder 46. The first bayonet closure 3 is arranged on a rotor 10 of an electric machine 12, which is surrounded by a stator 1 1 of the electric machine. On the stator 1 1 of the electric machine 12, a second bayonet lock 5 is arranged as a second interface for mounting the stator 6 of the grinder 46. Both between the rotor 10 and the stator 1 1 and between the supply pipe 7 and the rotor 10 seals 22, 23 are arranged in the region of the grinder, which prevent penetration of ground material 8 in the spaces above the seals 22, 23. The material to be ground 8 passes via a statically arranged filling pipe 18 into the supply pipe 7 of the supply unit 2 according to the invention. On the input side, the supply pipe 7 is provided with a flange which has an annular rolling bearing 9b between itself and the filling pipe 18. That way that can

Rotate feed tube 7 relative to the filler pipe 18. Also on the input side, a guide 19 is provided for the supply pipe 7, which on the other hand is fixed to the stator 1 1 of the electric machine 12. The guide 19 may slidably abut the supply pipe 7. If an annular rotary bearing 9a is arranged between the supply pipe 7 and the rotor 10 of the electric machine 12, the guide 19 can also be fixedly connected to the supply pipe 7 and the input-side annular rotary bearing 9b can be dispensed with, since now the supply pipe 7 can be designed to be fixed , On the output side, the mill 1 according to the invention is provided with an outlet tube 20, which is fixedly connected to the stator 1 1 of the electric machine 12. An outlet opening

21 is explosion proof designed to protect human and material when needed. Via a control unit 24 and a control line 25, the electric machine 12 can be supplied with electrical energy as needed.

FIG. 2 shows an alternative embodiment of the mill 1 shown in FIG. 1, so that only the essential differences of the mill 1 shown here will be discussed below. To blockages and one

To prevent overloading of the electric machine 12, a supply control in the form of an actuator 27 and 27 'is provided. The actuator 27 is arranged as a pivotable flap similar to a throttle valve in the filler pipe 18 and driven by a control line 26 via a control line 24. The control unit 24 is also (as described above) connected to the electric machine 12 by a control line 25. If the control unit 24 detects that an energy requirement of the electric machine 12 is increasing, it can bring the actuator 27 into the position of the actuator 27 'via the control line 26, thereby reducing the amount of ground material 8 flowing in and reducing the load on the electric machine 12. Accordingly, at a reduced load condition of the electric machine 12, the actuator 27 'can be brought back into the position of the actuator 27 to increase the flow of the material to be ground 8 again and processed per unit time

Grist quantity to adapt to the capacity of the electric machine.

FIG. 3 shows an alternative exemplary embodiment of the mill 1 shown in FIG. Here, an alternative embodiment of the actuator 27 can be seen, which is arranged as a cellular wheel or rotary valve 27 within a circular envelope structure. Turns the cell wheel or the

Rotary valve 27 faster, more material to be ground 8 is conveyed from the filling opening 18 in the supply pipe 7. The regulation results according to the in

Compound with Figure 2 described.

FIG. 4 shows an embodiment of the mill 1 shown in FIGS. 1 to 3 with respect to the grinding stock metering (actuator 27). The actuator 27 is configured as an annular membrane, which hydraulically or pneumatically can cause a tapering of the free cross section of the filler pipe 18. If the fluid pressure behind the membrane 27 is reduced, the membrane assumes the position of the membrane 27 '. If the fluid pressure behind the membrane 27 'subsequently increased again, the position of the membrane 27 results again

Use of pulsating fluid pressures to move the membrane 27, 27 'an additional advantage, which is as follows. Without changing the free cross-section within the filler pipe 18, pulsating fluid pressures can counteract blockage of the filler pipe 18 without a

Control by a control unit 24 (corresponding to Figures 2 and 3) is required.

FIG. 5 shows an exemplary embodiment of a mill 1 according to the invention, in which the electric machine 12 is arranged radially offset from the axis of the supply pipe 7. For mechanical energy transfer is a belt drive 13th used, which rotatably drives the first interface 3 for holding the rotor 4 of the grinder 46. The stator (not shown) of the electric machine 12 is in turn mechanically non-rotatably connected via the second interface 5 for holding the stator 6 of the grinder 46 to the stator 6.

FIG. 6 shows an embodiment modified on the basis of the exemplary embodiments of FIGS. 1 to 4, in which the feed tube 7 is referred to as FIG

hollow-walled double tube is configured. In this way results between an inner and an outer wall extending parallel to the flow direction of the material to be grounded 8 fluid channel with annular cross-section.

Ports 17 are provided for introducing fluid into the fluid passage 14 and into the space between the rotor 10 of the electric machine 12 and the outer wall of the supply pipe 7. In the latter

Interspace is thus generated an overpressure, which prevents inadvertent penetration of regrind 8. The use of the fluid channel 14 is in

Connection with the detail view explained in Figure 7, which illustrates the dash-dotted highlighted area A enlarged.

FIG. 7 shows an enlarged view of the region A marked in FIG. 6, in which the first and second interfaces 3, 5 are provided for holding the grinder 46 in the form of screw connections. At the lower end of the supply pipe 7, two outlets 16 are provided for fluid 15, by means of which the grinder 46 can be rinsed. Also, the path of the fluid 15 flowing between the supply tube 7 and the rotor 10 of the electric machine 12 along the seal 22 is illustrated by an arrow.

The present invention enables a particularly compact design and thereby savings in terms of height and required mechanical interfaces. This can be a significant cost reduction of the structure, the parts and the maintenance / armor of the mill according to the invention compared to in

State of the art known arrangements can be achieved. It can be a Tourque drives with almost constant torque over the speed used to drive the grinder. In addition, the use of a

Transmission of vibrations to the housing, the sieve insert and the

Siebrotor (grinder) can be optimized.

Claims

claims

1 . Supply unit (2) for a mill (1) comprising

a first interface (3) for supporting a rotor (4) of a

Grinder (46),

a second interface (5) for holding a stator (6) of the

Grinder (46),

a feed tube (7) which is adapted to guide ground material (8) in the grinder (46), and

an annular rotary bearing (9) on the feed tube (7), which is arranged such that in operation grinding stock (8) passes through the rotary bearing (9) in the grinder (46).

2. Feed unit according to claim 1, wherein

the rotary bearing (9) is a roller bearing or a slide bearing, and / or further a mixing element and / or a dispersing element and / or a loosening element and / or a conveying element for processing the ground material (8) in the feed unit (2) are provided.

3. Feeding unit according to claim 1 or 2, wherein the rotary bearing (9).

between the first interface (3) for supporting the rotor (4) and the supply pipe (7) is arranged.

4. Feeding unit according to one of the preceding claims, wherein the

Rotational bearing (9) between the second interface (5) for holding the stator (6) and the supply pipe (7) is arranged.

5. Feeding unit according to one of the preceding claims, wherein the first interface (3) for holding the rotor (4) of the grinder (46) mechanically non-rotatably and coaxially connected to a rotor (10) of an electrical machine (12). Feed unit according to one of the preceding claims, wherein the second interface (3) for holding the stator (6) of the grinder (46) mechanically non-rotatably and coaxially connected to a stator (1 1) of an electrical machine (12).

Feed unit according to one of the preceding claims 1 to 4, wherein the first interface (3) for holding the rotor (4) of the grinder (46) via a belt drive (13) or a chain with a rotor (10) of an electric machine (12). connected is.

Feed unit according to one of the preceding claims, wherein the feed tube (7) has an axially extending channel (14) for guiding a fluid (15) in the region of the grinder (46) arranged outlets (16).

Feed unit according to one of the preceding claims, further comprising a connection (17) for guiding a fluid (15) between the feed tube (7) and the first interface (3) for holding the rotor (4) of the grinder (46).

Comprising mill

a rotor (4) of a grinder (46), and

a stator (6) of a grinder (46), wherein

the rotor (4) at the first interface (4) and

the stator (6) are arranged on the second interface (5) of a supply unit (2) according to one of the preceding claims.