EP0867234B1 - Selective vibrating separator - Google Patents

Description

The present invention relates to a selective separator device vibrating, based on a classic screen box to which is applied a unidirectional vibration, and comprising a sorting system allowing to separate elements made of materials of nature very different in the agglomerated or separated state.

The screens allowing a selection of elements by their size are well known and used for a long time in different industries. A example is provided by GB 2 228 692, which presents a filing date dating back to 1990, and the design of which is based on displacement of elements to be sorted on a plurality of successive combs partially superimposed, between the teeth of which the parts to separate may fall depending on their size.

These partially superimposed combs, in fact constituting the ground a corridor at the entrance of which is sorted parts supply, are mechanically fixed to a frame to which a movement is applied vibratory for advancing said parts. They are grouped according to the size of their teeth, constituting for example two zones successive each surmounting a conveyor belt ensuring the evacuation of parts whose passage is authorized by the combs which overcome it.

The purpose of the screens described in GB 2 228 692 is therefore to proceed with a separation based essentially on the size of the elements that power the machine.

In the present invention, it is in fact a question of sorting elements by depending on their difference in nature, this being not only characterized by size, as is the case with conventional screens either as described above, or fitted with fabrics or sheets perforated with orifices only allowing the elements of smaller size to pass through said orifices, but by other properties such as density, hardness, shape, etc.

The problem is therefore much more complex, if only because there are many more parameters to take into account. In addition, very different behaviors of the elements subjected to vibrations do not allow not to easily formalize an implementation of the sorting, and the results obtained therefore required a significant amount of testing.

The principle which is the basis of the invention, allowing to achieve a separation of the elements at a satisfactory rate, lies in the characterization and the use of the behavior of each type of element composing the material complex to sort on contact with a vibrating surface, for given parameters of vibration.

In the following description, in order to facilitate understanding of the device the invention, the example which will be used relates to the separation of jets and weights aluminum flows, polymerized cores and soft sand, these elements from clusters of castings from an aluminum foundry. The behavior of the aforementioned elements in contact with vibrating surfaces provided specific equipment is very different, due to the individual response that they bring to the given vibration.

This answer depends in particular on the specific properties of each material, these in turn being linked to the physical characteristics of the elements. So the coefficient of friction, the tendency to roll, the possible abrasion, this last modification if necessary during the process some of the characteristics like weight and volume, are among the parameters that influence the differences in behavior when a predetermined vibration is applied to the system.

The problem is therefore to design an apparatus able to use these differences for separation / sorting purposes. Additionally, the modification of the state of certain elements during the process must also be taken into account and managed by said apparatus.

The separator of the invention, solving the problems posed previously, includes a classic vibrating box fitted with an equally traditional mechanism to generate unidirectional vibrations. This mechanism could for example be based on two motorcycle vibrators, or have a known mechanical exciter, or be made up of two crossed unbalanced trees. These equipment, conventional in current screens, and not being the subject of the invention, are therefore not described in detail in the context of the present description.

The box fitted to the invention comprises a sorting system consisting of troughs succeeding each other linearly, fed at one end of the succession by elements formed of materials of different nature, which occur in agglomerated or in a separate state, but not sorted, and are intended to move on said troughs.

In addition, the sorting of said elements is carried out by the combination between on the one hand the angle α, the amplitude a and the frequency η of the vibrations communicated to the troughs via the vibrating box, and on the other hand the configuration and the relative positioning of said troughs.

The optimization which is characteristic of the invention requires more particularly additional technical data, which are the subject of the following lines.

According to a main characteristic the successive troughs of the separator of the invention, of which one of axial ends of each trough comprising a filtering comb intended to trap small volume materials by gravity, one area to another axial end of each trough forms an angle with said surface main of the trough giving it an inclination relative to the horizontal angle γ greater than β, an axial end of each trough present a horizontal overlay area with the opposite axial end of the adjacent trough, are characterized in that the end of the filter comb of a trough is located below and at a horizontal distance | of the line of intersection of the two surfaces of angles γ and β of the adjacent trough which is less than the length of the corner portion γ, and at a vertical distance h from said portion of angle γ which is greater than the horizontal distance I.

The filter combs are intended to trap by gravitation of small volume materials.

They allow in particular to trap, in the illustrative example used, the blurred sand and small-sized polymerized cores based on sand.

Likewise, in order to be able to trap said blurred sand as continuously as possible, each trough may comprise on at least part of the surface on which move the items to be sorted, a screen cloth.

Preferably, the main surface of said troughs is inclined at an angle β by compared to the horizontal, so that the succession of troughs present for the materials to be separated a corresponding succession of jumps at the passage of a trough to the other.

The ability of the elements to move in one direction or the other, depending their own characteristics and the slope of the troughs, as well as their ability to make the jump between the troughs, are important factors of the sorting carried out by the invention, as will be seen in more detail below.

Said comb is preferably of a length greater than the area of horizontal overlay.

In such a configuration, part of the filter comb does not have of elements located between it and the system responsible for recovering the elements filtered. They can therefore drop down without obstacles and be recovered.

In the overlapping zone, on the contrary, there is an obstacle constituted by the zone of angle γ. However, it is not intended to act on the elements trapped by said comb, but on larger elements agitated with a movement which drives them, for example after falling from one trough to another, towards this inclined plane, then towards said recovery organs. The different movements which animate the items to be sorted will be discussed in more detail below.

In the particular example serving as a common thread in said description, the materials to be sorted are, as we have seen, jets and pouring weights aluminum, polymerized cores based on sand and fuzzy sand from clusters of aluminum castings.

• ± 0,03 ≤ a ≤ ± 0,035 (m)
• 35 ≤ α ≤ 45 (°)
• 900 ≤ η ≤ 1100 (Hz)
• 5 ≤ β ≤ 9 (°)
• 10 ≤ γ ≤ 15 (°)
• 0,08 ≤ h ≤ 0,12 (m)
• 0,06 ≤ l ≤ 0,1 (m).

For these particular types of materials, with their physical properties and the characteristics relating thereto, the values of the abovementioned parameters used for separation are included in the following ranges:

• ± 0.03 ≤ a ≤ ± 0.035 (m)
• 35 ≤ α ≤ 45 (°)
• 900 ≤ η ≤ 1100 (Hz)
• 5 ≤ β ≤ 9 (°)
• 10 ≤ γ ≤ 15 (°)
• 0.08 ≤ h ≤ 0.12 (m)
• 0.06 ≤ l ≤ 0.1 (m).

• a = ± 0,032 m
• α = 42°
• η = 1000 Hz
• β = 7°
• γ = 12°
• h = 0,1 m
• l = 0,08 m.

Fully satisfactory operation, validated by the tests, was obtained for the following more precise values:

• a = ± 0.032 m
• α = 42 °
• η = 1000 Hz
• β = 7 °
• γ = 12 °
• h = 0.1 m
• l = 0.08 m.

In this case, said operation is schematically as follows:

The jets and weights, the polymerized cores and the blurred sand supply continues the first trough, on which they vibrate according to the vibration parameters a, α and η.

The blurred sand, either coming directly from the feeding system, or detaching polymerized cores and aluminum parts due to vibrations, is filtered by the surface portions comprising a screen cloth, and / or by the end comb.

Each subsequent trough then traps the blurred sand in the same way.

Small agglomerated sand elements are also trapped in the level of the combs of each trough.

Larger nuclei are displaced along the troughs in the opposite direction of the progression of the aluminum elements.

They recede slowly, and partially disintegrate during their displacement, generating fuzzy sand which also undergoes the aforementioned treatment.

The steeper slope of the lower end of the troughs, near the jump zone, allows their evacuation. A number of nuclei are directly evacuated after jumping from one trough to another, when they fall on or in the immediate vicinity of the larger area.

Kernels whose physical characteristics are such that they could advance at least originally in the direction of progression of the pieces aluminum, also disintegrate due to vibrations and are treated with as explained above for soft sand.

The aluminum parts lose the sand which is agglomerated to them during their slow progression, always carried out since the start of the start, i.e. the one which is continuously fed by the unsorted elements, towards the last trough, from which they fall towards an evacuation system provided for this purpose.

The three materials making up the input elements are therefore separated during the continuous routing carried out by the machine.

• La figure 1 est une vue schématique d'un séparateur sélectif selon l'invention ;
• La figure 2 est une coupe longitudinale partielle, montrant notamment une auge selon la présente invention, ainsi que ses zones d'alimentation et d'évacuation ; et
• La figure 3 est une vue de dessus de ladite auge, partiellement représentée et localisée dans le caisson vibrant de l'invention.

The invention will now be described in detail with reference to the figures, for which:

• Figure 1 is a schematic view of a selective separator according to the invention;
• Figure 2 is a partial longitudinal section showing in particular a trough according to the present invention, as well as its supply and discharge zones; and
• Figure 3 is a top view of said trough, partially shown and located in the vibrating box of the invention.

In the separator shown in Figure 1, the direction of progression of aluminum elements is symbolized by the arrow F.

The separator box (1) is traditional, for example made up of two vertical walls connected to each other by cross beams, and it is equipped of a mechanism (2) known per se generating a unidirectional vibration. Said vibration (v) is symbolized by the double arrow which provides at the same time its direction. The parameters (a, α, η) are the amplitude, the angle with respect horizontally and the frequency of this vibration (v).

The reception area (3) for the materials to be sorted is located under a strip conveyor (4) bringing said materials continuously.

The troughs (5) follow one another axially from left to right, each comprising at least two distinct zones as will be seen below.

The blurred sand and the polymerized sand cores are recovered in a vibrating chute (6) which conveys the sand laterally to a simple bucket handled or, preferably, a band carrying out the evacuation in continuous waste.

The same goes for the bucket (7), intended for the recovery of the elements metal, which can be replaced by an automated conveyor belt.

In the separator of the invention, only the reception area (3) and the last trough (5) are preferably provided with screening cloth, with openings calibrated from 5 mm, allowing to sift the blurred sand. In the other troughs, trapping said blurred sand is preferably made at the level of the jumping zones.

Figure 2 is an enlargement of a possible configuration of the troughs (5, 5 ', 5 ") comprising the essential features of the invention.

The main surface (8) forming the longest section of the trough (5), is inclined by an angle β, while the zone of greatest slope (9), located under the comb (10) of the previous trough (5 '), is inclined at an angle γ. The meaning of reading (F) of this diagram is reversed compared to figure 1. The parts metallic aluminum therefore in this figure from the right to the left, jumping from the comb (10) of a trough (5) towards the zone of slope γ of the trough next (5 ") then progressing slowly on the main surface (8) of said trough (5 "), whether or not fitted with screening cloth.

When these aluminum parts reach the comb (10), the cycle start again. At this level, said parts get rid of agglomerated sand that the vibrations v have detached parts during the progression. Sand indeed progresses in the same direction as said metal parts.

The nuclei generally progress in the opposite direction to the arrow F and disappear under the effect of their weight, towards the bottom of the box (1), direction of the recovery system (6). The same goes for nuclei cured which have jumped from one trough (5) to the other, which separate at this level metallic elements, which plunge directly towards the area angle γ, then towards the bottom of the box (1).

The configuration shown in this figure is only an example of an illustration, and the troughs (5, 5 ', 5 ") can of course be constructed of any other way, if they subscribe to the essential features of the invention.

The particular geometry appearing in the jump areas is also important in the context of the invention. Given the elements to be sorted, the length I and height h must be chosen with care, and validated by trials.

Figure 3 shows the components of Figure 2, in partial top view for the troughs (5, 5 ', 5 "). Each is in fact half represented in width, so that their axial ends are clearly visible.

This figure shows a possible configuration of the combs (10), as well as the partial overlap of said combs with the zone of greatest slope (9) troughs (5, 5 ', 5 "). The top view also allows you to view an order of size for length I.

The direction of operation is identical to that of the previous figure. The small pieces of sand and blurred sand are trapped on the combs and pass below the troughs (5, 5 ', 5 ").

The blurred sand is also sieved on the fabrics of the reception area (3) and from the last trough (5 ").

On the slope of the main surface (8), the aluminum parts rise slowly, as well as the fuzzy sand and small nuclei, while the others nuclei slowly recede and partially disintegrate again forming sand advancing in reverse.

Other nuclei are trapped directly at the time of the jump, and they are immediately evacuated via the steepest area.

Claims (7)

1. Selective vibrating separator comprising a box (1) to which a unidirectional vibration is applied, said box (1) comprising a sorting system constituted by a succession of troughs (5, 5', 5") in a straight line, fed at one of the ends of the succession with elements formed of materials of different nature present in separated or agglomerated state, designed to move over said troughs (5, 5', 5"), the sorting of said elements being achieved by the combination of firstly the angle α, the amplitude a and the frequency η of the vibrations communicated to the troughs (5, 5', 5") via the vibrating box (1), and secondly the configuration and the relative positioning of said troughs (5, 5', 5"), one of the axial ends of each trough (5, 5', 5") comprising a filtering comb (10) designed to trap materials of small volume by gravitation, a zone (9) situated at the other axial end of each trough (5, 5', 5") forming an angle with said main surface of the trough (5, 5', 5"), giving it an inclination in relation to the horizontal of angle γ greater than β, one axial end of each trough (5, 5', 5") exhibiting a horizontal superposed zone with the opposite axial end of the adjacent trough (5, 5', 5"), characterised in that the end of the filtering comb (10) of a trough (5, 5', 5") is located within and a horizontal distance 1 from the line of intersection of the two surfaces (8, 9) of angles γ and β of the adjacent trough (5, 5', 5") which is less than the length of the portion (9) of angle γ, and a vertical distance h from said portion (9) of angle γ which is greater than the horizontal distance l.
2. Selective vibrating separator according to the preceding claim, characterised in that over at least one portion of the surface (8) over which said elements move, each trough (5, 5', 5") comprises a screening cloth.
3. Selective vibrating separator according to any one of the preceding claims, characterised in that the main surface (8) of said troughs (5, 5', 5") is inclined at an angle β in relation to the horizontal so that the succession of troughs (5, 5', 5") exhibits a corresponding succession of jumps for the materials to be separated when passing from one trough to the other.
4. Selective vibrating separator according to any one of the preceding claims, characterised in that the axial end of each trough (5, 5', 5") is provided with a comb (10) with a length greater than the horizontal superposed zone.
5. Selective vibrating separator according to any one of the preceding claims, characterised in that the materials to be sorted are splashes and dead heads from aluminium castings, polymerised cores based on sand and fuzzy sand emanating from moulding clusters produced by an aluminium foundry.
6. Selective vibrating separator according to the preceding claim, characterised in that the values of the parameters used for the separation lie within the following ranges:

   ± 0.03 ≤ a ≤ ± 0,035 (m)

   35 ≤ α ≤ 45 (°)

   900 ≤ η ≤ 1100 (Hz)

   5 ≤ β ≤ 9 (°)

   10 ≤ γ ≤ 15 (°)

   0.08 ≤ h ≤ 0.12 (m)

   0.06 ≤ 1 ≤ 0.1 (m).
7. Selective vibrating separator according to the preceding claim, characterised in that the values adopted are the following:

   a = ± 0.032 m

   α = 42°

   η = 1000 Hz

   β = 7°

   γ = 12°

   h = 0.1 m

   l = 0.08 m.

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