A waste paper sorting conveyor for sorting waste paper from waste cardboard

IS 2 136 363 T5

DESCRIPTION

Selection conveyor for separating waste paper from waste cardboard.

Technical field

Waste paper and waste cardboard are generally collected in a mixed fashion. However, for recycling it is preferable to separate the typically brown cardboard from the waste paper, since the inclusion of substantial amounts of waste cardboard in the raw material from which the paper is to be made results in a relatively gray or brown paper. . The invention relates to an apparatus for sorting waste paper from waste cardboard.

Previous technique

A waste paper sorting conveyor according to the preamble of claim 1 is known from practice.

In operation, a mixture of waste paper and waste cardboard is fed to the front end of the sorting conveyor. The rotating motion of the impellers intermittently pushes the material on the front conveyor and forward in the conveying direction. Thus, the material on the conveyor is simultaneously agitated and transported along the conveyor. Since mix paper is typically smaller in size and more flexible than cardboard, conveyor paper tends to fall through gaps between shafts and impellers, while cardboard tends to stay on the side. top of the conveyor. Thus, the predominantly cardboard material can be collected at the downstream end of the conveyor or succession of conveyors and the predominantly paper material can be collected from below the conveyor.

A problem with this known sorting conveyor is that in most cases a satisfactory degree of sorting does not occur. Too much paper is included in the classified paper and / or too much cardboard is included in the classified paper.

In WO 95/35168 a waste sorter is disclosed comprising a frame, a plurality of cylinders mounted on the frame substantially parallel to each other and defining a substantially planar alignment, means for rotating the shafts in mating relationship with each other. and a plurality of discs mounted on the shafts in a substantially coplanar row. The discs are held in place on the shafts by spacers, using spacers of different lengths to determine the spacings between the discs. Changing the spacings between the discs of this type of sorting conveyor is a very time consuming operation.

Summary of the invention

It is an object of the present invention to provide a sorting conveyor with which a generally more satisfactory degree of sorting can be achieved, allowing quick adjustment of the axial gaps between the impellers.

According to the invention, this object is achieved by providing a sorting conveyor of the type described above with the characteristic features of claim 1.

By releasably attaching the single row impellers to the respective shaft to allow adjustment along the axis in a release condition, simple readjustment of the lateral spacing between the impellers is made possible.

In turn, this allows a better adjustment of the classifier to changes in the material to be classified and to changes in the classification requirements. Increasing the size of the gaps allows material of generally larger maximum size and greater stiffness to fall through the interspace. By decreasing the size of the gaps, material of generally smaller size and less stiffness is prevented from falling through the interspace.

Thus, the sorting properties can be adjusted exactly to the composition of the waste material mixture fed to the sorting conveyor, the demand for waste paper and waste cardboard and any requirement related to the maximum and minimum proportion of paper in the classified cartoon, and vice versa, as regards the maximum and minimum portion of the cartoon on the classified paper.

It has been found, for example, that the composition of paperboard waste in urban areas is substantially different from the composition of the same type of waste in rural areas. It has also been discovered that the composition varies from one country to another, being the distribution of the thickness and size of newspapers and magazines and the type of cardboard used topically important factors that determine the structure of waste paper and cardboard. In addition, in some cases the waste carton is required which includes approximately 10% waste paper. Instead of simply adding paper to the waste cardboard after sorting, this type of composition can be obtained more efficiently using the sorting apparatus according to the invention by narrowing the gaps so that the desired composition is directly obtained. As an advantageous side effect, the degree to which the sorted paper includes cardboard impurities is then reduced.

Another possibility of improved adjustment of the sorting conveyor to variations in the composition of paper and board material to be sorted can be obtained, provided that the position of at least one of the axes in the direction of the conveyor can also be adjusted.

Another possibility of improved adjustment of the sorting conveyor to variations in the composition of the paper and board material to be sorted can be obtained, provided that the rotational speed of the impellers can also be adjusted. In particular, if the combination of spacing in the conveying direction and rotational speed of the impellers can be adjusted independently in at least two sections of the conveyor, a substantially improved degree of purity can be achieved.

ES 2 136 363 T5 classified materials over a wide range of paperboard and paper mix compositions to be classified. Other objects, features and advantages of the present invention appear from the following description, in which a preferred embodiment of the present invention is described with reference to the drawings. Especially advantageous embodiments of the present invention are also described in the dependent claims.

Brief description of the drawings

Figure 1 is a schematic side view of a sorting conveyor system in accordance with the present invention.

Figure 2 is a side view of the sorting conveyor system shown in Figure 1 in another arrangement.

Figure 3 is a schematic top plan view of a section of the sorting conveyor system according to figure

1.

Figure 4 is a cross-sectional side view along line IV-IV in figure

3.

Figure 5 is a side view according to figure 4 with impellers in different rotational positions.

Fig. 6 is a view according to Fig. 1 showing the steering system and discharge means of the sorting conveyor system shown in Figs 1-5.

Figure 7 is a view according to Figure 6 in an arrangement corresponding to the arrangement shown in Figure 2.

Figure 8 is a detailed side view of a drive member of the sorting conveyor system shown in Figures 1-7.

Figure 9 is a detailed cross-sectional view along line IX-IX in Figure 10; Y

Figure 10 is a detailed side view of a section of the sorting conveyor system shown in Figures 1-9. Ways to carry out the invention

The waste paper sorting conveyor system shown in the drawing comprises two sorting conveyors 1, 2. The upstream conveyor 1 of the conveyors shown has a front end positioned over the rear end of the front conveyor 2 , so that the material that has passed over the rear conveyor 1 falls onto the front conveyor 2. The system also includes a feed conveyor 3 which is shown only in Figures 1, 2 and 6 and the discharge conveyors 4, 5, 6 are only shown in Figure 6.

Each of the classifying conveyors 1, 2 is provided with a row of rotary, driven shafts 7 (not all shafts are designated by reference numbers). The shafts 7 are arranged at mutually spaced positions in a transport direction (arrow 8) and each extends in a direction perpendicular to the transport direction. Each of the shafts 7 carries a row of radially extending impellers 9 (not all the impulse members are designated by reference numbers) to intermittently push the material on the sorting conveyors 1, 2 up and in the direction of transportation 8. The impellers 9 of each of the axes 7 are mutually spaced in the longitudinal direction of the respective axis 7 and the rotational contours 10 (see Figures 4 and 5) of the impellers 9 carried by each of the axes 7 project between the rotational contours 10 'of the impellers 9 carried by one of the neighboring axes 7.

Each of the conveyors 1, 2 is also provided with a motor-transmission unit 12 (figures 6, 7 and 9) and with transmission systems to drive the axles 7. Each of the transmission systems includes sprockets 13 ( Not all the sprockets 13 are designated by reference numbers) mounted on the shafts 7, to transmit drive forces exerted by the respective motor 12. The sprockets 13 are coupled by a chain 14 (omitted in figure 9) that passes over the sprockets 13, over the deflection wheels 15 (not all the deflection wheels 15 are designated by reference numbers) and over idler wheels. 16. Tensioning wheels 16 are rotatably suspended from a tensioning structure 17 (Figure 10) that is adapted to elastically exert a tensioning force in a direction indicated by arrows 18 in Figures 6 and 7. chain are well known in the art and are therefore not described in further detail.

In operation, the material to be sorted is fed along the infeed conveyor 3. From there, the material is deposited on the rear sorting conveyor 1. The rear sorting conveyor 1 conveys the material in the conveying direction 8 by rotating the impellers 7 in the direction of transport 8.

Since the impellers include radially projecting parts, in this corner-shaped embodiment 11, the material on the conveyor 1 is simultaneously intermittently pushed upward and thus agitated, increasing the likelihood that Sufficiently small and / or flexible items that pass through open spaces on conveyor 1 will eventually fall through conveyor 1. Material that has not fallen through conveyor 1 and has reached the forward end thereof is dropped into forward sort conveyor 2, where the same sorting treatment is repeated. Dropping the material being sorted as it passes over the two conveyors 1, 2 provides the advantage that very intensive additional agitation and mixing of the material is obtained, so that any paper article that is Even if it is supported on top of the cardboard items it reaches a position below the cardboard material, allowing that paper item to fall through the second conveyor 2.

Material that has fallen through conveyors 1, 2 (predominantly waste paper) is carried along discharge conveyors 4, 5. Material that has also pa3

By the forward conveyor 2 without falling through it falls into a third discharge conveyor 6 and is carried to another location.

The mutual spacing between the impellers 9 of each axis 7 is adjustable in the longitudinal direction of that axis 7.

If, for example, the carton in a mix includes relatively few small, flexible items, a wide spacing can be selected to achieve maximum paper throughput without undue sacrifice in the purity of the sorted waste paper. On the other hand, if the waste paper includes relatively few large, stiff items such as books or other bonded stacks of paper, a small spacing can be selected to achieve maximum paper purity without undue sacrifice of paper production.

Other factors that determine an optimal adjustment of the spacing between the drivers are the relationship between demand and prices of waste paper and waste cardboard, and the requirements related to the maximum and minimum proportion of paper in the classified cardboard and, at the same time, inversely, in relation to the maximum and minimum portion of cartoon in the classified paper.

The positions of all except one of the axes 7 of each conveyor 1, 2 are adaptable in relation to the other axes 7 in the direction of transport 8.

By adjusting the position in the conveying direction of the shafts 7 with respect to each other, the size in the conveying direction of the spacing between the respective shaft 7 and the next successive and / or preceding shafts 7 can also be changed. By increasing the size of a gap, material of generally larger maximum size and stiffness is allowed to fall through the interspace, that is, less paper reached the third discharge conveyor 6 and more cartoons reached the first and second. discharge conveyors 4 and 5. By reducing the size of a gap, material of generally smaller minimum size and stiffness is prevented from falling through the interspace, that is, more paper reached the third discharge conveyor 6 and less cardboard reached the first and second paper conveyors. download 4 and 5.

Thus, also the spacings in the conveying direction can be adjusted exactly to the characteristics of the mix of paper and board material fed to the sorting conveyors 1, 2. It should be noted that the adaptability of the positions of the shafts 7 in the direction of transport is also advantageous if the impellers are arranged on the shafts in fixed positions, but that in combination with the lateral adaptability of the spacings between the impellers 9, can achieve particularly good classification results, probably because the dimensions of the spacings between the impellers in both longitudinal and transverse directions can be adapted to the size and flexibility distributions of the paper and board in the material to be classified.

Since the positions of each of the adaptive shafts 7 of each of the conveyors 1, 2 in relation to the other respective shafts 7 can be adjusted independently in the conveying direction 8, it is possible not only to adjust the spacing between successive shafts 7, but also vary the spacings as a function of the distance in the direction of transport along the conveyors, depending on the structure of the materials to be classified.

In most cases, it is preferable that the size of the spacings in the longitudinal and transverse direction between the impellers and shafts is generally increased in the direction of transport.

Thus, the spacings found by the material fed to the rear transport lane 1 are initially relatively small, so that, initially, very small items are classified, while keeping the amount of cardboard at the same time. that falls through it. After the material has traveled some distance along the conveyor track, the larger, stiff items have generally assumed positions where they are essentially flat on the conveyor track 1. In these types of positions, the cartoon articles can pass through larger spacings with little or no probability of falling through them, so that increasing the size of the spacings as a function of the distance traveled by the material that passes in the respective space, increased paper yield can be obtained without sacrificing the degree of purity of the sorted paper. The same principle applies to front conveyor 2.

Each of the classifying conveyors 1, 2 consisted of a rear section 29 and a front section 30. The mutual spacings between the axles 7 in the rear sections 29 and between the axles 7 in the front sections 30 are independently adjustable. Since the rear and front sections 29, 30 of each of the sorting conveyors 1, 2 are driven by separate chains 14, the circumferential speeds of the shafts 7 in each of the rear and front sections can be controlled independently of each other. . Thus, the circumferential speed of the impellers 9 in each section can be controlled according to the size in the conveying direction of the spacings between the shafts 7 and the drive plates 9. Preferably, a higher circumferential speed is selected if larger spacings are adjusted in the transport direction. Increasing the circumferential speed in the forward direction further provides the advantage that the items on the sorting conveyor are pushed outward as they reach the forward sections, increasing the likelihood that smaller items will pass through larger gaps between the items. big maos.

The drive wheels 13 are positioned in a row. The deflection wheels 15, which are also rotatable, are arranged along the row of drive wheels 13 in staggered relation to the row of wheels.

ES 2 136 363 T5 transmission 13. The drive chain 14 is alternatively coupled on the transmission wheels 13 and the deflection wheels 15. This transmission structure allows the shafts 7 carrying the impellers 9 to move in the Direction of transport over substantial distances without requiring structural changes in the transmission structure or even the repositioning of the deflection wheels 15.

A particularly efficient construction is obtained because the deflection wheels 15 are mounted on a support structure in fixed positions.

It should be noted that the rear sections of the rear conveyor 1 in Figures 1 and 6 have five axes 7, while the corresponding sections in Figures 2 and 7 have only four axes

7. By allowing the elimination of axes 7, the spacing between successive axes along a given track can be extended more than if the settings were restricted to settings of a fixed number of axes to the length of that track. The chain 14 at the rear parts of the rear conveyors 1 in Figures 2 and 7 is coupled with the rear deviation wheel 15 which is shown in dotted lines jumping at the same time. Depending on the selected arrangement and the length of the chain 14, various ways of guiding the chain 14 are available, on the deflection wheels 15 and the transmission wheels 13.

In the drawings, the rear sections of both conveyors 1, 2 are shown in an arrangement in which the chain also jumps on a deflection wheel 15. The spare deflection wheels 15 allow an additional axle to be fitted. In other arrangements, it may be advantageous to skip a deflection wheel 15 instead of the most advanced deflection wheel 15.

To allow adjustment of the positions of the shafts 7 in the direction of transport, the support members 19 of the shafts 7 are detachably mounted on the rails 20 which extend along the conveyors 1, 2 in the direction of transport. transport 8. The rails 20 are provided with a row of holes along the length of the rails 20. By inserting bolts through the support member 19 and through selected holes, the support members 19, and therefore the shafts 7, can be fixedly inserted at the desired positions. It will be apparent that many other constructions are feasible for adjustably positioning the shafts, such as clamping the support members on the rails.

To prevent waste material from escaping from the conveyors in lateral direction, the conveyors 1, 2 are provided with guide plates 21. To allow adjustment of the shafts 7 without removing the guide plates 7, grooves 22 are provided in guide plates 7. The slots 22 in turn are elastically closed by brushes 23 that prevent waste material from falling through the slots 22, but do not interfere with the adjustment, removal or addition of any of the shafts 7.

To facilitate the drive of the conveyor from the transmission motor units 12, which are in fixed positions, one of the shafts 7 of each of the transmitters 1, 2 is mounted in a fixed position.

Since the axles 7 in fixed positions are central axes 7 located between the front and rear axles 7 in adaptable positions, a given readjustment of the spacings between the axles 7 implies a relatively small maximum displacement of the axles 7. If, for example, the fixed axis were positioned at one end of the conveyor, a given proportional readjustment would require, for example, a displacement of the axis at an opposite end of the conveyor approximately twice as large as the displacement of the axes 7 at the ends of the conveyor. conveyors 1, 2 with fixed center shafts 7.

An efficient and compact construction of the conveyor is further promoted by arranging the transmission motor units 12 closely adjacent to the fixed shafts 7 and particularly by providing a direct drive from the reduction transmission of the unit 12 to the respective fixed shaft 7.

As can best be seen in figure 8, the impellers 9 are releasably clamped on the shafts 7, which are preferably of a polygonal cross section. This allows for easy readjustment of the lateral spacing between successive impellers 9 in a row. Thus, not only the spacing in the conveying direction, but also the lateral spacing between the successive impellers 9 can easily be adapted to the properties of the material to be classified and the requirements regarding the classified materials. The latter advantage can also be achieved if fixed impellers of the type described above are applied to a sorting conveyor whose impeller bearing shafts are not adjustable.

Furthermore, each of the impellers 9 was provided with an opening 24 through which the shaft 7 carrying that impeller extends. A release part 25 can move when in a released condition. When the releasable part 25 is in the displaced condition, a radial pitch is obtained to pass the shaft 7 radially in and out of the opening 24. This impeller construction allows the impellers 9 to be mounted and disassembled outside the shafts 7 without disassembling the shafts 7. Thus, if a damage to an impeller 9 or a readjustment of the lateral spacing between the impellers 9 requires the assembly or disassembly of Impellers 9, Impellers 9 can be disassembled from shaft 7 and mounted on shaft 7 without disassembling shaft 7 or requiring a shaft having a free end on which the impeller can be mounted. In particular, given the fixed width of the sorting conveyors 1, 2, the lateral adjustment of the mutual, lateral spacing between the impellers 9 of a shaft 7 would generally necessitate the elimination or addition of at least one set of push plates 9.

The impellers 9 of the sorting conveyors shown can be manufactured especially efficiently, since the impeller body was made up of two mutually identical parts 25. The parts 25 are detachably fixed around one of the axes 7 bearing that impeller 9 by means of bolts 26

ES 2 136 363 T5 which engage the plug-shaped nuts 27 on the opposite parts. The body of the impeller can also advantageously be formed by more than two identical parts fastened around the axis.

The contour of the impellers 9 with corners 11 projecting radially outward and outwardly curved sections 28, the corner 11 projecting more outward than at least adjacent portions of the curved sections 28, is advantageous because, on the one hand, it generates a Substantial intermittent vertical movement of the material bearing on the bed formed by the impellers 9 when the impellers 9 rotate, but, on the other hand, it provides a relatively large minimum overlap between the impellers 9 carried by successive axes 7. Furthermore, when the impellers 9 carried by successive axes 7 are in orientations in which the curved sections 28 face each other, as shown in Figure 5, relatively sloping cradle-shaped edges are obtained from the intermediate spaces between successive drive-shaft assemblies, that cause any material that tends to fall through that interspace to be gradually pushed into a flexed condition allowing passage through that interspace. To prevent even small, but rigid cardboard articles from falling through gaps between successive rows of impellers 9, the spacings between successive shafts 7 are preferably set so that impellers 7 of neighboring shafts 7 mutually overlap at each position. rotation of the respective impellers 9.