ITUD20100059A1 - SCREENING EQUIPMENT TO SELECT DIFFERENT AVENTIONAL MATERIALS DIMENSIONS - Google Patents

Description

Description of the invention having as title:

"SCREENING EQUIPMENT TO SELECT MATERIALS WITH DIFFERENT SIZES"

FIELD OF APPLICATION

The present invention relates to a screening apparatus for selecting materials having different dimensions, such as, for example, wood splinters or shavings, pieces of paper, or plastic material, or fibrous elements, and finds application in various industrial sectors for recovery of recycled material, such as in the wood, rubber, plastic and municipal solid waste sectors.

In particular, the apparatus according to the present invention allows to carry out a sorting, or screening, of materials having different dimensions, in order to separate the smaller pieces from the larger ones.

STATE OF THE TECHNIQUE

Various technologies are known for the dimensional selection of flows of coherent or incoherent material. For obtaining fractions of material with precise granulometry, or when very thorough sieving is required, the most efficient known sieving apparatus is that which uses a sieve subject to vibration or oscillation.

When the flow of material has a high degree of incoherence (different geometries, dimensions, materials of the individual particles) and a high degree of humidity, the sieve system is no longer functional and therefore other systems are adopted.

Some examples are disc or roller screens used, for example, in the wood sector, such as the one described in the Italian patent IT-B-1.330.681, in the name of the Applicant, where the selection is carried out by a train of rotating elements. in an concordant sense, coupled together so as to define predefined discharge ports of variable size, in the direction of advancement of the material flow. These are efficient and more versatile machines than the classic oscillating or vibrating screens, but the degree of undifferentiation of the flow to be treated is however limited. In fact, it has been found that when the screening of material with a large surface, or with fibrous elements is required, they present clogging or blocking problems, because the aforementioned materials tend to roll up around the screening rollers, disadvantageously reducing the dimensions of the discharge ports and altering the level of differentiation of the flow of material to be treated.

Further known equipment are the drum screens, used in waste recovery plants, which include a rotating drum, horizontal or inclined and fed by the flow of falling material and a peripheral net, fixed on the drum, with differentiated meshes along the longitudinal development. of the machine, which allow the separation of the different fractions. These equipments, even if they are very versatile, as they can select any flow of material and are simple from the constructive point of view, are not very efficient.

Further known screens are the ballistic ones, which exploit the different reactions of heavy or light particles to mechanical impulses provided by blade systems, but which also have poor selection efficiency.

An object of the present invention is to provide an apparatus for the dimensional selection of materials or elements having different dimensions, which does not present clogging and blocking problems.

A further object of the present invention is to provide an apparatus having a differentiation efficiency higher than that of known apparatuses, while maintaining maximum versatility in the treatment of material with different degrees of undifferentiation.

In order to obviate the drawbacks of the known art and to obtain these and further objects and advantages, the Applicant has studied, tested and implemented the present invention.

EXPOSURE OF THE FOUND

The present invention is expressed and characterized in the independent claim. The dependent claims disclose other characteristics of the present invention or variants of the main solution idea.

In accordance with the aforementioned purposes, a screening apparatus for selecting materials having different dimensions, according to the present invention, comprises a separation chamber in which said materials are able to be inserted, a plurality of screening rollers mounted, rotating on axes parallel to each other and lying substantially on the same plane of said separation chamber, and a rotating motor member.

According to a characteristic aspect of the present invention, the equipment further comprises a transmission device suitable for transforming the rotation of said rotating motor member, into an alternative rotary motion of said screening rollers, in a clockwise and counterclockwise direction, of lower amplitude. 360 °, so that the rotation of each screening roller occurs in the opposite direction to that of the adjacent screening roller, to allow the advancement of said materials inside said separation chamber.

According to an embodiment, the amplitude of rotation of said screening rollers is comprised between 30 ° and 90 °, for example 65 °.

In this way the screening rollers, being subject to a rotary and reciprocating movement, allow to advantageously treat also fibrous materials and large surface dimensions, without the latter rolling around the rollers themselves, thus increasing the efficiency of the equipment. according to the present invention.

Advantageously, said screening rollers are divided into the two series, which are arranged offset from each other by one position.

In particular, said transmission device comprises a first transmission mechanism adapted to move a first series of screening rollers and a second transmission mechanism adapted to move a second series of screening rollers.

According to another characteristic of the present invention, said transmission mechanisms each comprise a crank, a connecting rod, a bar and arms for connecting to the screening rollers. In particular, each crank is keyed to the aforementioned rotating motor member and is connected to the corresponding connecting rod, which, in turn, is connected to the connecting bar.

Each arm is hinged on the corresponding bar and keyed to a screening roller.

Advantageously, the crank of the first transmission mechanism is keyed onto the rotating motor member, offset by 180 ° with respect to the crank of the second transmission mechanism. This embodiment allows the first series of screening rollers to rotate in a direction of rotation opposite to that of the second series.

Advantageously, the first series of screening rollers comprises first screening elements having a determined shape while the second series of screening rollers comprises second screening elements having a shape different from that of the first.

In particular, the first screening elements are shaped in such a way as to have two active surfaces converging towards each other towards the center, which are adapted to facilitate the transfer of materials, from a screening roller to the adjacent one.

Each of the second screening elements, on the other hand, comprises two upper cusps which are also adapted to facilitate the transfer of materials from a screening roller to the adjacent one, and a lower cusp designed to facilitate the passage of the materials downwards, through the ports. drain.

ILLUSTRATION OF DRAWINGS

These and other characteristics of the present invention will become clear from the following description of a preferential embodiment, given by way of non-limiting example, with reference to the attached drawings in which:

- fig. 1 is a perspective view of a screening apparatus according to the present invention;

- fig. 2 is a top view of the apparatus of fig. 1;

- fig. 3 is a first side view of the apparatus of fig. 1;

- fig. 4 is a second side view, schematic and partially sectioned, of the apparatus of fig. 1;

- figs. 5 to 8 show in sequence some details of the apparatus of fig. 1 in some operating positions. To facilitate understanding, identical reference numbers have been used wherever possible to identify identical common elements in the figures. It should be understood that elements and features of one embodiment can be conveniently incorporated into other embodiments without further specification.

DESCRIPTION OF A PREFERENTIAL FORM OF

REALIZATION

With reference to fig. 1 a screening apparatus 10 according to the present invention, for selecting materials having different dimensions, comprises a supporting metal structure 11 substantially parallelepiped in shape and having two side walls 15 and 16 which define a separation chamber 12, open downwards .

The materials to be sorted are suitable for being introduced into the separation chamber 12 from above through a hopper opening 18 (fig. 3).

Inside the separation chamber 12 there is a first series of screening rollers 13 (fig. 1) and a second series of screening rollers 14, which is offset by one position with respect to the first series of screening rollers 13. In the present case, the screening rollers 13 are five, while the screening rollers 14 are four.

In this way the five screening rollers 13 are arranged in the odd positions (first, third, fifth, seventh and ninth) while the four screening rollers 14 are arranged in the even positions (second, fourth, sixth and eighth).

Both the screening rollers 13 and the screening rollers 14 are rotatably mounted on the side walls 15 and 16 of the structure 11 and have their axes of rotation parallel to each other and lying substantially on the same plane, so as to form a single bed of screening. The aforesaid plane can be either horizontal or inclined by a few degrees, advantageously upwards, to increase the screening efficiency of the materials. Each screening roller 13 comprises a shaft 20 on which a plurality of first screening elements 17 (fig. 4) are mounted, side by side and spaced apart by means of the interposition of known type spacer rings.

Each screening roller 14 comprises a shaft 25 on which a plurality of second screening elements 19 are mounted, also side by side and spaced from each other by means of the interposition of known type spacer rings.

The screening elements 17 and 19 are arranged in a comb-like pattern (Fig. 2), so as to define discharge ports through which the materials to be screened can pass.

One end of each shaft 20 protrudes from the side wall 15, while one end of each shaft 25 protrudes from the side wall 16.

The screening apparatus 10 also comprises an electric motor 30 which, by means of a reducer 34, is able to transmit the motion to a rotating shaft 38 which in turn, by means of a transmission device 31, transmits the motion to the screening 13 and 14.

In particular, the transmission device 31 is adapted to transform the continuous rotation of the shaft 38, in a certain direction of rotation, into an alternative rotary motion of the screening rollers 13 and 14, in a clockwise and counterclockwise direction, of width β (fig. 3), advantageously 65 °, so that the rotation of each screening roller 13, 14 always takes place in the opposite direction to that of the adjacent screening roller 14, 13.

In particular (fig. 2), the transmission device 31 comprises, on each side of the supporting structure 11 and externally to the side walls 15 and 16, a first transmission mechanism 40 and a second transmission mechanism 41, substantially the same, but mirrored. between them, each of which in turn comprises a crank 33 (figs. 2 and 3), a connecting rod 35, a bar 36 and connecting arms 37.

Each crank 33 is keyed to the shaft 38 and is connected to the corresponding connecting rod 35, which in turn is connected to the corresponding bar 36. The connecting arms 37 are hinged to the latter. keyed to shafts 20, respectively 25.

The crank 33 (fig. 2) of the first transmission mechanism 40 is keyed onto the motor shaft of the gearbox, offset by 180 ° with respect to the crank 33 of the second transmission mechanism 41, so that, when the crank 33 of the first transmission mechanism 40 is in the lower dead center position, i.e. when the connecting rod 35 and the bar 36 are in the position of maximum excursion to the right, the crank 33 of the second mechanism 41 is in the upper dead center position, i.e. with the connecting rod 35 and the bar 36 in the position of maximum excursion to the left.

When the two cranks 33 are rotated by the electric motor 30, the first and second transmission mechanisms 40 and 41 impart a substantially pendular motion to the connecting arms 37, so that the screening rollers 13 and 14 connected to them perform a rotary and reciprocating motion, and with a direction of rotation which is opposite for the screening rollers 13 with respect to that of the screening rollers 14.

The separation chamber 12 (fig. 4) below the mouth 18, comprises a plurality of conveyor blades 42, fixedly mounted to the bearing structure 11, which allow the materials to be screened to be conveyed towards the first screening roller 13, avoiding that, inside the separation chamber 12, there are dead zones in which the materials can accumulate.

In a similar way, on the side opposite to the feed side, a plurality of receiving blades 43 are fixed, which convey the materials towards an unloading opening 45.

In particular, each first screening element 17 (Fig. 5) comprises two active surfaces 21 and 22, which converge towards the center and form an angle a of about 170 °, to facilitate the transfer of materials.

Each second screening element 19 is instead shaped with a different geometry compared to that of the first screening element 17 and comprises an upper surface 23 and a lower surface 24. The upper surface 23 includes two upper cusps 26 and facilitate the transfer of materials to be screened M towards the adjacent screening roller 13. The lower surface 24 comprises, near one of its ends, a lower cusp 27 which favors the downward passage of the materials M between the screening elements 17.

The operation of the screening apparatus 10 described up to now is as follows.

The materials to be screened M are fed into the separation chamber 12, through the mouth 18 (figs. 3 and 4). A part of the materials M of smaller dimensions passes through the discharge ports defined by the first screening roller 13, while the remaining part is screened by the screening bed formed by the screening roller 13 and 14. In particular, the materials M remain on the surfaces active elements 21 and 22 (Fig. 5) of the first screening elements 17. In this configuration, the active surface 22 is parallel to the plane on which the trees 20 and 25 lie which, in this case, is horizontal. The direction of rotation of the first elements 17 is counterclockwise, while that of the second elements 19 is clockwise.

During the alternating rotation of the screening rollers 13 and 14, the non-screened materials M are advanced towards the discharge opening 45, i.e. towards the left in Figs. from 4 to 8, thanks to the thrust exerted by the active surfaces 22 of the first elements 17, while the screened materials are pushed downwards by the lower surfaces 24 of the second elements 19. During the thrust exerted by the active surfaces 22, the non-screened materials M undergo impacts both with each other and with the screening elements 17 and 19, which cause the detachment of the individual parts that make up the materials M.

When the first and second elements 17 and 19 reach their maximum rotation (fig. 7), i.e. when the active surfaces 22 have been rotated by the angle β with respect to the horizontal condition, the active surfaces 22 of the first elements 17 discharge the material M not screened on the upper surfaces 23 of the second elements 19

After reaching this position, which also corresponds to that shown in fig. 3, the screening rollers 13 and 14 reverse their direction of rotation.

During the return rotation towards the initial position of fig. 5, passing from the intermediate position shown in fig. 8, the materials M arranged on the upper surfaces 23 of the second elements 19 undergo a thrust towards the left, that is towards the first adjacent elements 17. After a rotation of 65 ° all the screening elements 17 and 19 return to the initial position shown in fig. 5 to receive further material on their active surfaces 21 and 22 again.

It is clear that modifications and / or additions of parts can be made to the screening apparatus described up to now, without departing from the scope of the present invention.

For example, the transmission device can be made using one or more transmission chains, or toothed wheel kinematics connected to the two series of screening rollers, in order to carry out the movements described above.

It is also clear that, although the present invention has been described with reference to some specific examples, a person skilled in the art will certainly be able to realize many other equivalent forms of screening apparatus, having the characteristics expressed in the claims and therefore all falling within the scope of the scope of protection defined by them.

Claims (10)

CLAIMS 1. Screening apparatus for selecting materials (M) having different dimensions, comprising a separation chamber (12) in which said materials (M), a plurality of screening rollers (13, 14) rotatably mounted on rotation axes parallel to each other and lying substantially on the same plane of said separation chamber (12), and a rotating motor member (38), characterized in that it also comprises a transmission device (31) adapted to transform the rotation of said rotating motor member (38), in a reciprocating rotary motion of said screening rollers (13, 14), clockwise and counterclockwise, with an amplitude (β) less than 360 °, so that the rotation of each roller of screening (13, 14) takes place in the opposite direction to that of the adjacent screening roller (14, 13), to allow the advancement of said materials inside said separation chamber (12). 2. Screening apparatus as in claim 1, characterized in that said screening rollers (13, 14) comprise a first series of screening rollers (13) and a second series of screening rollers (14), and that said first series of screening rollers (13) is arranged in said separation chamber (12) offset by one position with respect to said second series of screening rollers (14). 3. Screening apparatus as in claim 2, characterized in that said transmission device (31) comprises a first transmission mechanism (40) adapted to move said first series of screening rollers (13) and a second transmission mechanism ( 41) adapted to move said second series of screening rollers (14). 4. Screening apparatus as in claim 3, characterized in that said first transmission mechanism (40) and said second transmission mechanism (41) each comprise a crank (33) fixed to said rotating motor member (38) and connected to a connecting rod (35), which is connected to a bar (36), on which a plurality of connecting arms (37) are hinged, each of which is fixed to one of said screening rollers (13, 14 ). 5. Screening apparatus as in claim 4, characterized in that the crank (33) of said first transmission mechanism (40) is fixed to said rotating motor member (38), offset by 180 ° with respect to the crank (33) of said second transmission mechanism (41). 6. Screening apparatus as in any one of claims 2 to 5, characterized in that said first series of screening rollers (13) comprises first screening elements (17) each having two active surfaces (21 and 22) converging towards each other. the center is adapted to favor the transfer of said materials (M), from said first screening rollers (13) to said second screening rollers (14). 7. Screening apparatus as in any one of claims 2 to 5, characterized in that said second series of screening rollers (14) comprises second screening elements (19) each having two upper cusps (26) adapted to favor the transfer of said materials (M), from said second screening rollers (14) to said first screening rollers (13). 8. Screening apparatus as in claim 7, characterized in that said second screening elements (19) further comprise a lower cusp (27), adapted to facilitate the passage of said materials (M) downwards. 9. Screening apparatus as in claim 1, characterized in that the amplitude of rotation (β) of said screening rollers (13, 14) is comprised between 30 ° and 90 °. 10. Screening apparatus as in claim 9, characterized in that the rotation amplitude (β) of said screening rollers (13, 14) is 65 °.