DE102015200924A1 - Coaxial mill and feed unit for a mill - Google Patents

Abstract

A mill (1) and a feed unit (2) for a mill (1) are proposed. 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 supply pipe (7) which is arranged to guide ground material (8) into the grinding mechanism (46), and - an annular rotation bearing (9) on the feed tube (7), which is arranged such that, during operation, ground material (8) passes through the rotation bearing (8). 9) enters the grinder (46).

Description

State of the 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 granulates grain size reduction for the tabletting process or particle size reduction for wet granules in order to dry them faster or to give this structure to improve 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 5,405,094 shows a multi-stage mill, in which two screening units are used by means of rotationally driven stirring elements for the comminution of ground material. The stirring elements are driven by a shaft, which is supplied by means of a belt with kinetic energy.

US 5,863,004 shows a mill in which a arranged on a sieve element stirring element is moved by a downstream drive unit to press ground material through the sieve unit.

The mills known in the 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 thus expensive. Sometimes an increased set-up time can adversely affect the process reliability of an entire system. At times, prior art mills require additional brackets and pushers to bring the mills into working position, to equip (e.g., screen change, rotor screen tool), to clean and to service. 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 holding a stator of the grinder, which causes the comminution of the ground material in cooperation with the rotor by a relative movement between the rotor and the stator. Further, a supply pipe is 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 feed pipe such that the grinding material passes through the rotary bearing into the grinder during operation. In other words, the annular rotary bearing encloses at least a portion of a free pipe cross-section of the feed pipe so that the millbase is conveyed through the "eye" of the rotary bearing and through the feed pipe. In particular, all regrind is brought by the rotary bearing in the grinder. In this way, the geometry of the grinder as well as its attachment and accessibility for set-up and maintenance purposes can be made extremely low, whereby 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 can roll between an inner and an outer or an upper and a lower ring of the bearing to allow a particularly low frictional force at high pressure forces to be transmitted. Such a roller bearing can be configured as a roller bearing or as a ball bearing. The plain bearing can have material combinations with a particularly low sliding friction coefficient (eg nylon and metal), whereby 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 can be arranged to rotate about the supply tube.

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 is located between the feed tube and a stationary part of the mill or other fixed structure (for example, an upstream feed tube). 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 interface for holding the stator of the grinder and the supply pipe may be arranged. Also in this case, the supply pipe of the feed unit according to the invention can perform a rotational movement relative to the stator of the grinder while it is non-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, conveying elements may be attached to the rotor / stator system in the feeder 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 improve the flow capabilities and / or the service life of the grinder.

According to a second aspect of the present invention, a mill is proposed, which may be configured, for example, as a process mill in production technology. 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 arranged at the first interface and the stator 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 is constructed by mounting a rotor and a stator of a grinder on a feed unit according to the invention. Of course, additional parts (eg for closing a feed opening for ground material and / or for closing a discharge opening for ground material and / or other elements (eg dispersing elements for breaking lumps, product bridges) or conveying elements may be included.

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 rotating thread in the rotor of the grinder may be provided to allow a reversible, yet fixed mounting of the rotor to the supply 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 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:

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

2 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;

3 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;

4 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;

5 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;

6 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

7 a detailed view illustrating possible embodiments of the first and second interface and seals and fluid channels.

Embodiments of the invention

1 shows an embodiment of a mill according to the invention 1 which a feed unit according to the invention 2 having. The feed unit 2 has a first bayonet lock 3 as the first interface for mounting a rotor 4 a grinder 46 on. The first bayonet lock 3 is on a rotor 10 an electric machine 12 arranged, which of a stator 11 surrounded by the electric machine. At the stator 11 the electric machine 12 is a second bayonet lock 5 as a second interface for mounting the stator 6 of the grinder 46 arranged. Both between the rotor 10 and the stator 11 as well as between the supply pipe 7 and the rotor 10 are in the area of Grinder seals 22 . 23 arranged, which is an intrusion of regrind 8th in the spaces above the seals 22 . 23 prevent. The regrind 8th passes through a statically arranged filler pipe 18 in the supply pipe 7 the feed unit according to the invention 2 , On the input side is the supply pipe 7 provided with a flange, which is an annular rolling bearing 9b between itself and the filler pipe 18 having. In this way, the feed tube 7 opposite the filler pipe 18 rotate. Also on the input side is a guide 19 for the supply pipe 7 provided, which on the other hand on the stator 11 the electric machine 12 is attached. The leadership 19 can be lubricious at the feed tube 7 issue. If an annular rotary bearing 9a between the supply pipe 7 and the rotor 10 the electric machine 12 arranged, the guide can 19 also stuck to the supply pipe 7 be connected and the input side annular rotary bearing 9b can be omitted, since now the supply pipe 7 can be configured fixed. On the output side is the mill according to the invention 1 with an outlet pipe 20 provided, which firmly with the stator 11 the electric machine 12 connected is. An outlet opening 21 is explosion proof designed to protect people and material when needed. About a control unit 24 and a control line 25 can the electric machine 12 be supplied with electrical energy as needed.

2 shows an alternative embodiment of the in 1 illustrated mill 1 , so that below only the main differences of the mill shown here 1 will be received. To blockages and overloading of the electric machine 12 to prevent is a supply control in the form of an actuator 27 respectively. 27 ' intended. The actuator 27 is as a hinged flap similar to a throttle in the filler pipe 18 arranged and motorized via a control line 26 by a control unit 24 drivable.

The control unit 24 is also (as described above) with the electric machine 12 through a control line 25 connected. Detects the control unit 24 that an energy requirement of the electric machine 12 it can rise over the control line 26 the actuator 27 in the position of the actuator 27 ' bring, reducing the amount of incoming grinding material 8th decreases and the load on the electric machine 12 is reduced. Accordingly, at a reduced load condition of the electric machine 12 the actuator 27 ' back to the position of the actuator 27 be brought to the stream of ground material 8th again to increase and adjust the processed per unit time Mahlgutmenge to the capacity of the electric machine.

3 shows an alternative embodiment for the in 2 shown mill 1 , Here is an alternative embodiment of the actuator 27 to recognize which as a cellular wheel or rotary valve 27 is arranged within a circular envelope structure. Rotates the cell wheel or the rotary valve 27 faster, becomes more regrind 8th from the filling opening 18 in the supply pipe 7 promoted. The regulation results in accordance with in connection with 2 Described.

4 shows a with respect to the Mahlgutdosierung (actuator 27 ) Modified embodiment of the in the 1 to 3 shown mill 1 , The actuator 27 is designed as a circular membrane, which hydraulically or pneumatically a taper of the free cross-section of the filler pipe 18 can cause. If the fluid pressure behind the membrane 27 decreases, the membrane takes the position of the membrane 27 ' one. If the fluid pressure behind the membrane 27 ' subsequently increased again, the position of the membrane results again 27 , The illustrated embodiment allows for the use of pulsating fluid pressures to move the membrane 27 . 27 ' an additional advantage, which is as follows. Without the free cross section inside the filler pipe 18 To change, pulsating fluid pressures can block the filler tube 18 Counteract without a control by a control unit 24 (corresponding 2 and 3 ) is required.

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

6 shows a based on the embodiments of the 1 to 4 , modified embodiment, in which the supply pipe 7 is designed as a hollow-walled double tube. In this way results between an inner and an outer wall parallel to the flow direction of the ground material 8th extended fluid channel with annular cross-section. connections 17 are for introducing fluid into the fluid channel 14 as well as in the space between the rotor 10 the electric machine 12 and the outer wall of the feed tube 7 intended. In the latter gap thus an overpressure is generated, which is an inadvertent penetration of regrind 8th prevented. The use of the fluid channel 14 is used in conjunction with the detail view in 7 explained, which illustrates the dash-dotted highlighted area A enlarged.

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

The present invention enables a particularly compact design and thereby savings in terms of height and required mechanical interfaces. As a result, a significant cost reduction of the structure, the parts and the maintenance / armor of the mill according to the invention over arrangements known in the art can be achieved. It can be a Tourque drives with almost constant torque over the speed used to drive the grinder. In addition, the insert can be optimized by transmitting vibrations to the housing, the sieve insert and the sieve rotor (grinder).

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5405094 [0004]
• US 5863004 [0005]

Claims (10)

Supply unit ( 2 ) for a mill ( 1 ) - a first interface ( 3 ) for mounting a rotor ( 4 ) of a grinder ( 46 ), - a second interface ( 5 ) for mounting a stator ( 6 ) of the grinder ( 46 ), - a supply pipe ( 7 ) which is set up, regrind ( 8th ) into the grinder ( 46 ), and - an annular rotary bearing ( 9 ) at the feed tube ( 7 ), which is arranged such that during operation regrind ( 8th ) through the rotary bearing ( 9 ) into the grinder ( 46 ). Feed unit according to claim 1, wherein - the rotary bearing ( 9 ) is a roller bearing or a plain 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 ( 8th ) in the supply unit ( 2 ) are provided. Feed unit according to claim 1 or 2, wherein the rotary bearing ( 9 ) between the first interface ( 3 ) for holding the rotor ( 4 ) and the feed tube ( 7 ) is arranged. Feeding unit according to one of the preceding claims, wherein the rotary bearing ( 9 ) between the second interface ( 5 ) for mounting the stator ( 6 ) and the feed tube ( 7 ) is arranged. Supply unit according to one of the preceding claims, wherein the first interface ( 3 ) for holding the rotor ( 4 ) of the grinder ( 46 ) mechanically non-rotatable and coaxial with a rotor ( 10 ) an electric machine ( 12 ) connected is. Feeding unit according to one of the preceding claims, wherein the second interface ( 3 ) for mounting the stator ( 6 ) of the grinder ( 46 ) mechanically non-rotatable and coaxial with a stator ( 11 ) an electric machine ( 12 ) connected is. Feeding 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 ) an electric machine ( 12 ) connected is. Feeding unit according to one of the preceding claims, wherein the supply pipe ( 7 ) an axially extending channel ( 14 ) for guiding a fluid ( 15 ) in the area of the grinder ( 46 ) arranged outlets ( 16 ) having. Supply 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 ). Grinder comprising - a rotor ( 4 ) of a grinder ( 46 ), and - a stator ( 6 ) of a grinder ( 46 ), where - the rotor ( 4 ) at the first interface ( 4 ) and - the stator ( 6 ) at the second interface ( 5 ) of a supply unit ( 2 ) are arranged according to one of the preceding claims.

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