WO2017085681A1

WO2017085681A1 - Pelletizer machine

Info

Publication number: WO2017085681A1
Application number: PCT/IB2016/056965
Authority: WO
Inventors: Massimo Basso
Original assignee: Teka Srl
Current assignee: Teka Srl
Priority date: 2015-11-19
Filing date: 2016-11-18
Publication date: 2017-05-26
Anticipated expiration: 2018-05-19
Also published as: EP3377313A1; CH711831A2; CH711831B1

Abstract

The present invention relates to a pelletizer machine (1), comprising a fixed load-bearing structure (3) on which at least an annular die (2) is solidly mounted, provided with radial through-holes (4) defined on a lateral surface thereof; a pressure wheel (5) being mounted internally of the annular die (2), rotatably constrained to an eccentric portion of a shaft (9) having a first end rotatably constrained to said fixed load-bearing structure (3); the shaft (9) being further set in rotation about an axis substantially parallel to the axis of the pressure wheel (5) and to the axis of said annular die (2). The particular feature of the present invention is that the machine comprises a head structure (14) for rotating support of a second end (15) of the shaft (9), opposite the first end; the head structure (14) is solidly mounted to the fixed load-bearing structure (3) so as to prevent bending and/or axial displacements of the shaft (9).

Description

Description of the industrial invention titled:

PELLETIZER MACHINE

DESCRIPTION

The present invention relates to a pelletizer machine usable both for production of combustible pellets and for preparation of fertilizers and feeds in the form of pellets.

As is known, pelletizer machines, or pellet- forming machines, are machines which by subjecting a material to an extremely high pressure, by passing the material internally of a die develop a temperature that is such as to enable cohesion of the material, which takes on the form of small cylinders.

The process of pelletizing can be applied both for production of fuels or fertilizers, using shavings, wooden chips or bio-masses such as for example clippings, maize, straw, wine marcs, olive residues, paper and cardboard, or can be used for production of feed for any type of animal, obviously using raw materials suitable for the purpose.

Pelletizer machines comprise in general one or more pressure wheels conceived and moved in such a way as to press the material against the surface of an extrusion die provided with through-holes, up to reducing it to the form of pellets. In a first type of machine the above-mentioned pressure wheels are arranged, with a horizontal axis, above dies that are substantially flat or, alternatively, internally of horizontal-axis cylindrical dies.

Other pelletizers on the other hand have pressure wheels, having a vertical axis, located internally of substantially annular dies.

In both cases, the power required for good functioning of the machine is considerable, as indeed is the level of maintenance needed.

These drawbacks have been at least in part obviated by the pelletizer press described and claimed in patent for invention no. 0001369007, which discloses commanding a vertical-axis pressure wheel with an eccentric movement, so as to reduce the torque arm necessary .

This solution however has some critical aspects mainly linked to the fact that following the stress to which it is subjected, the shaft moving the pressure wheels tends to bend, or displace axially, compromising the correct functioning of the machine.

Another critical aspect relates to the fact that in the above-mentioned machine a part of the material to be pelletized tends to lodge beneath the pressure wheels, leading to seizure.

A further drawback of the cited machine relates to the wear of the moving parts, which must be periodically replaced, with inevitable maintenance and machine down-time costs.

The main aim of the present invention is therefore to provide a pelletizer machine able to obviate the drawbacks of the prior art.

Within the scope of the above-mentioned aim, a particular objective of the invention is to realise a pelletizer machine which, given a same pellet produced, is able to considerably reduce the power required in the pelletizing process and at the same time enables preventing the risk of jamming or blocking of the parts in motion due to bending and/or axial displacements of the shaft transmitting the motion to the pressure wheels .

A further aim of the invention is to realise a pelletizer machine which enables obviating the issues related to the wear on the mechanical parts of the machine that are under stress.

Another object of the invention is to realise a pelletizer machine in which the risk of seizure is practically non-existent.

A further object of the invention is to realise a pelletizer machine that is compact and reliable.

The above-mentioned task, as well as the aims set down, and others which will more fully emerge in the following, are attained by a pelletizer machine, comprising a fixed load-bearing structure on which at least an annular die is solidly mounted, provided with radial through-holes defined on a lateral surface thereof; a pressure wheel being mounted internally of said annular die, rotatably constrained to an eccentric portion of a shaft having a first end rotatably constrained to said fixed load-bearing structure said shaft being set in rotation about an axis substantially parallel to the axis of said pressure wheel and to the axis of said annular die; said machine being characterised in that it comprises a head structure for the rotating support of a second end of said shaft, opposite said first end; said head structure being solidly mounted to said fixed load-bearing structure so as to prevent bending and/or axial displacements of said shaft.

Additional features and advantages will become more apparent from the description of a preferred, but non-exclusive embodiment of a pelletizer machine, illustrated by way of indicative and non-limiting example in the appended drawings, in which: figure 1 is a perspective view of a pelletizer machine according to the invention;

figure 2 is a perspective view of a section of the pelletizer machine according to the invention;

figure 3 is a schematic front view of the section of figure 2;

figure 4 is an enlarged view of a detail of figure

3;

figure 5 is another enlarged view of the detail represented in figure 4;

figure 6 is a perspective view of a part of the pelletizer machine according to the invention;

figure 7 is another perspective view of the pelletizer machine according to the invention.

With reference to the cited figures, a pelletizer machine is denoted in its entirety by reference number 1.

The machine 1, in the preferred embodiment thereof, comprises an annular die 2, having a substantially vertical axis, solidly mounted on a fixed load-bearing structure 3 which has a substantially cylindrical conformation.

The annular die 2 is provided with a plurality of radial through-holes 4 for extrusion of the pellet, calibrated and internally smooth, which open onto the lateral surface thereof.

A pressure wheel 5 having a substantially vertical axis is mounted internally of the annular die 2, which pressure wheel 5 essentially consists of a truncoconical body delimited by a truncoconical surface 6 which overlies a cylindrical lateral surface 7, which is able to interact with the internal lateral surface of the annular die 2.

The pressure wheel 5 is rotatably constrained to the eccentric portion 8 of a shaft 9 and is idle about an axis thereof.

The base of the pressure wheel 5 overlies a disc^¬ shaped balancing organ 10 that is integral in rotation with the shaft 9 and located above a base wall 11 of the fixed load-bearing structure 3.

The shaft 9 is substantially vertically located, with the axis parallel to the axes of the annular die 2 and the pressure wheel 5, and has a first end 12 rotatably constrained to the fixed load-bearing structure 3 by means of a first rotational bearing 13.

During the use of the machine 1, the shaft 9 is set in rotation by motorised activating means which, being of themselves of known type are not described. According to the present invention, the machine 1 comprises a head structure 14 for rotating support of a second end 15 of the shaft 9, opposite the first end 10.

The head structure 14 is advantageously solidly mounted to the fixed load-bearing structure 3 so as to prevent bending and/or axial displacements of the shaft 9.

In greater detail, the head structure 14 consists of a substantially hollow body delimited by a bottom wall 16 and by a substantially cylindrical lateral wall 17 solidly mounted to the annular die 2 ;

A seating 18 is defined at the centre of the bottom wall 16 for an axial thrust-bearing assembly 19 which houses a second rotational bearing 20 associated to the second end 15 of the shaft 9.

A series of infeed openings 21 for the material to be pelletized is also appropriately fashioned on the bottom wall 16.

The openings 21 are distributed almost symmetrically and are conceivable in such a way as to place the outside of the machine 1 with a pressing chamber 22 internally of which the pressure wheel 5 is housed .

The pressing chamber 22 is delimited by a combination of the internal surfaces of the substantially hollow body which constitutes the head structure 14, by the annular die 2 and by the fixed load-bearing structure 3.

According to a further aspect of the invention, a dispensing device 23 of the material to be pelletized is predisposed internally of the pressing chamber 22.

The device 23 is preferably constituted by a disc^¬ shaped body 24, integral in rotation with the shaft 9, from which one or more blades 25 radially project and are appropriately profiled, located in proximity of the openings 21.

A further important aspect of the present invention relates to the presence of a wear compensating device for the pressure wheel 5 and the annular die 2, not illustrated in the figures.

In greater detail, the above-mentioned device is conceived in such a way as to enable the position of the pressure wheel 5 to be regulated with respect to the eccentric portion 8 of the shaft 9, via axial translation .

In other terms, by using the wear compensating device it is possible to near, more or less, the pressure wheel 5 to the base wall 11 of the fixed load- bearing structure 3, as illustrated by way of example in figures 4 and 5.

For this purpose, it is important to emphasise that the surfaces of the pressure wheel 5 and the annular die 2 destined to interact with one another are not only parallel but also inclined with respect to the base wall 11.

This detail enables conserving the interactive ability of the pressure wheel 5 and the annular die 2 almost unvaried, even following the relative axial displacements .

A further important aspect of the present invention relates to the presence of a plurality of discharge channels 26 vertically fashioned on the base wall 11 for placing the inside of the pressing chamber 22 in communication with the outside of the machine 1.

In greater detail, the discharge channels 26 open into the space comprised between the balancing organ 10 and the surface of the base wall 11 and are connected by means of a circumferential recess 27 defined on the fixed load-bearing structure 3.

The presence of discharge channels 26 enables evacuating the excess material which otherwise would tend to accumulate below the pressure wheel 5, capable of possibly causing a seizure.

The functioning of the machine according to the present invention is as follows.

With an appropriate loading system, which is not part and parcel of the present invention, the material to be palletized is introduced into the pressing chamber 22 through the openings 21.

Internally of the pressing chamber 22 the material is uniformly dispensed from the device 23 and by sliding on the truncoconical surface 6 of the pressure wheel 5 accumulates in the gap existing between the latter and the annular die 2.

At the same time, the motorised activating means set the shaft 9 in rotation which, via the eccentric portion 8 thereof, transmits the motion also to the pressure wheel 5.

In this regard, it is of interest to emphasise that being the pressure wheel 5 idle with respect to the eccentric portion 8 it does not rotate about the axis thereof but has an eccentric motion which however leads to interaction with the annular die 2, in a gradual and alternating way.

More precisely, during a whole revolution of the shaft 9, the pressure wheel 5 is progressively displaced from one end to another of the internal surface of the annular die 2, touching all points thereof .

The material to be pelletized can thus accumulate in the gap which is progressively created as a consequence of the distancing of the pressure wheel 5 from the annular die 2, then to be gradually pressed into the radial through-holes 4 during the nearing thereof, determining the formation of the pellet.

During the pressing, a part of the excess material would tend to lodge beneath the pressure wheel 5, but it is effectively evacuated from the discharge channels 26, preventing any risk of seizure.

It is also worthy of note that the interaction between the pressure wheel 5 and the annular die 2 inevitably determines a wearing thereof, though minimal with respect to known machines, which however can be compensated for by using the wear compensating device.

The pelletizer machine according to present invention therefore offers numerous and varied advantages with respect to known machines.

In particular, given a same pellet produced, the pelletizer machine of the invention enables considerably reducing the power required in the pelletizing process and at the same time enables preventing the risk of jamming or blocking of the parts in motion caused by bending and/or axial displacements of the shaft 9 during the transmission of the motion to the pressure wheel 5.

A further advantage consists in the fact that the machine 1 enables obviating the problems connected to the wear on the mechanical parts subjected to stresses.

It is also worthy of note that risk of seizure is also notably reduced with the machine of the invention. The pelletizer machine of the invention is also compact and reliable.

In practice, it has been noted that the pelletizer machine according to the invention fully achieves the prefixed tasks and aims.

The pelletizer machine as conceived herein is susceptible to many modifications and variations, all falling within the scope of the concept of the invention; furthermore, all the details may be replaced by technically equivalent elements.

Naturally, the materials used, as long as they are compatible with the specific use, the dimensions and the contingent shapes can be varied according to needs and to the state of the art.

Claims

1. A pelletizer machine, comprising a fixed load- bearing structure on which at least an annular die is solidly mounted, provided with radial through-holes defined on a lateral surface thereof; a pressure wheel being mounted internally of said annular die, rotatably constrained to an eccentric portion of a shaft having a first end rotatably constrained to said fixed load- bearing structure; said shaft being set in rotation about an axis substantially parallel to the axis of said pressure wheel and to the axis of said annular die; said machine being characterised in that it comprises a head structure for the rotating support of a second end of said shaft, opposite to said first end; said head structure being solidly mounted to said fixed load-bearing structure so as to prevent bending and/or axial displacements of said shaft.

2. The machine according to the preceding claim, characterised in that said head structure consists of a substantially hollow body delimited by a bottom wall and by a substantially cylindrical lateral wall solidly mounted to said annular die; said bottom wall defining a seating for an axial thrust-bearing assembly able to house at least a rotational bearing of said second end of said shaft.

3. The machine according to one or more of the preceding claims, characterised in that said substantially hollow body comprises one or more infeed openings of the material to be pelletized; said openings being able to place an outside of said machine in communication with a pressing chamber containing said pressure wheel; said pressing chamber being delimited jointly by said substantially hollow body, said annular die and said fixed load-bearing structure.

4. The machine according to one or more of the preceding claims, characterised in that it comprises a dispensing device of the material to be pelletized arranged internally of said pressing chamber.

5. The machine according to one or more of the preceding claims, characterised in that said dispensing device of the material to be pelletized comprises at least a blade that is integral in rotation with said shaft; said blade being arranged internally of said pressing chamber adjacent to said infeed openings of the material to be pelletized.

6. The machine according to one or more of the preceding claims, characterised in that said pressure wheel is constituted by a substantially truncoconical body rotatably constrained to said eccentric portion and idle about an axis thereof; said substantially truncoconical body being arranged on a substantially disc-shaped balancing organ; said balancing organ being integral in rotation with said shaft and being arranged on a base wall of said fixed load-bearing structure.

7. The machine according to one or more of the preceding claims, characterised in that said substantially truncoconical body comprises a cylindrical lateral surface interacting with the internal lateral surface of said annular die; said cylindrical lateral surface being joined to a truncoconical surface facing towards said bottom wall of said substantially hollow body.

8. The machine according to one or more of the preceding claims, characterised in that it comprises a wear compensating device of said pressure wheel and said annular die; said wear compensating device being adapted to regulate the position of said pressure wheel with respect to said eccentric portion, by means of axial translation; said lateral surface of said substantially truncoconical body and said internal lateral surface of said annular die being substantially parallel to one another and inclined with respect to said base wall.

9. The machine according to one or more of the preceding claims, characterised in that it comprises one or more discharge channels obtained on said base wall for communication between an outside of said machine, the space comprised between said balancing organ and said fixed load-bearing structure, and a circumferential recess defined on said base wall.

10. The machine according to one or more of the preceding claims, characterised in that the axis of the pressure wheel and the axis of said annular die are substantially vertical.