FR2556246A1 - DEVICE FOR THE SEPARATION OF SHEET MATERIALS IN A WASTE TREATMENT FACILITY - Google Patents

Abstract

1. A device for separation of sheet material in an apparatus for treatment of refuse, comprising separation means, stop means for the sheet materials, a cyclone (28), a second duct (27) between said stop means and the cyclone, a third duct between the cyclone and the separation means, and a blower (31) for ensuring a flow of air in a circuit formed between the separation means, the stop means, the cyclone, and back to the separation means, through said second and third ducts, characterised in that said separation means comprises a first passage (9), substantially vertical, and means (10, 14) for causing in this first passage an ascending flow of air, in that said device comprises a first duct (16) of venturi shape between said first passage and said stop means to close said air circuit, and in that said first and third ducts open substantially opposite each other on to the upper part of said first passage to cause a transverse flow of air.

Description

The present invention relates to a device for the separation of

  sheet materials in a waste treatment facility.

  It is known to produce humus from waste, for example from household waste. It is known, however, that only fermentable materials are involved in the formation of humus, whereas non or little fermentable materials such as plastic bags, rags, paper, cardboard, etc. may, on the contrary, be advantageously used.

as fuels.

  The present invention aims to provide a device for the separation of sheet materials which constitute, in waste and more particularly in urban waste, an essential part of

  non-ferrous and non-fermentable materials.

  For this purpose, the invention relates to a device for the separation of sheet materials in a waste treatment plant, characterized in that it comprises a first substantially vertical sheath, means for causing in this first sheath an ascending air flow, a first conduit opening to the upper portion of said first sheath, and air suction means in said first conduit to cause at the upper portion of said sheath a loaded transverse air flow said sheet materials and

  penetrating into said first conduit.

  The sheet materials which on the one hand are light and on the other hand have a large surface are thus driven by the upward flow at the upper part of the sheath where they are entrained by the transverse flow in the first duct. their subsequent processing. Said first sheath may for example be the supply sheath of a first shredder. In the case of a hammer mill, it can participate itself, by its rotation, in the formation of the air flow.

ascending.

  Advantageously, said first sheath forms a venturi below the zone through which said first duct opens, which has the effect of

  to cause an acceleration of the rising airflow.

  In a particular embodiment of the invention, the upper surface of said first duct is inclined upwards in the direction of

  the inside of the sheath in its area adjacent to said sheath.

  This provision is intended to prevent heavy materials, projected for example by the impact of the hammer mill, do not engage in the first conduit. Such heavy materials hit the surface

  tilted, and are thus returned to the sheath where they fall downwards.

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  The lower surface of said first duct may instead be inclined downwards towards the interior of the duct in its zone.

adjacent to said sheath.

  This measure also aims to prevent the penetration into the first conduit of heavy products since they would be brought by sliding on the lower surface of the first conduit to fall back into the sheath. According to a preferred embodiment of the invention, the device comprises means arranged at the end of said first conduit to stop

said sheet materials.

  A second conduit from said halting means can then cause the air flow, freed of said sheet materials, to

cyclone for its dusting.

  The materials in sheets are thus recovered on the means

  provided at the end of the first conduit.

  A third conduit can then be planned from the cyclone to

recycle the dusted air.

  This third duct advantageously opens into said first sheath substantially vis-à-vis said first duct to achieve

  the transverse air flow under the best conditions.

  Said means for stopping the sheet materials preferably comprise a receiving member such as a grid or a wire mesh disposed in a plane transverse to the air flow at the end of said first duct and movable in this plane of the position o it is across said flow at positions where it is away

of this flow.

  Thus the sheet materials are, at the outlet of the first conduit, pressed against the receiving grid which is across the air flow and then are brought by the movement of this gate outside the flow at a point o they stand out from themselves from the grid. According to another aspect of the invention, it also relates to a device for the separation of sheet materials in a waste treatment plant, characterized in that it comprises a first conduit, means for driving in this first conducts a charged air flow of said sheet materials, and a receiving member such as a grid or wire mesh disposed in a plane transverse to the air flow at the end of said first conduit and movable in this plane of the position where it is across said

  flow at positions where it is away from this flow.

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  In any case, said receiving member is preferably constituted by one of the strands of a grid mat rotating in front of

  the end of said first conduit.

  In a particular embodiment of the invention, said receiving member is substantially vertical and is arranged to move downwardly from the position where it is across said flow to

  positions o it is away from this flow.

  Thus the sheet materials which are pressed against the grid are driven down and then fall off the grid when the grid portion on which they are located is brought out of the air flow. An air collection box may be disposed behind said receiving member, said box having a first opening

  substantially vis-à-vis said end of the first conduit.

  This box may also have a second opening to which is connected a second conduit for the evacuation of the removed air

said sheet materials.

  In a particular embodiment of the invention, said receiving member is disposed inside a second substantially vertical sheath, this second sheath constituting the sheath.

  feeding a second mill.

  Thus, the recovered sheet materials can be crushed for further processing, for example for processing.

in combustible granules.

  A particular embodiment of the invention will now be described by way of nonlimiting example with reference to the appended diagrammatic drawings in which: FIG. 1 is a perspective view of a device according to the invention, FIG. is an enlarged view of the air collection chamber shown in FIG. 1 and FIG. 3 is a sectional view along the line III.III of FIG.

figure 1.

  The device shown in the drawing generally comprises a feed assembly 1 of waste, for example of urban waste, a set 2 for separating the sheet materials and grinding the other materials, a set 3 for recovery and grinding materials in

  sheets, and a set 4 of dusting and recycling of air.

  The assembly 1 comprises a belt conveyor 5 whose upper end is disposed above an endless belt 6 scales -4-

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  metal with blades 7 for opening the plastic bags generally used for the collection of urban waste. The endless belt 6 conveys the waste to an opening 8 formed in one of the vertical walls of a vertical feed sheath 9 of a hammer mill 10. A stop plate 11, whose height is adjustable using a member 12 such as a screw and whose lower part is also provided with opening blades 13,

  is disposed at the entrance of the orifice 8 above the end of the carpet 6.

  Thus, the waste is brought onto this carpet 6 where the plastic bags are opened using the blades 7 and 13, after which the waste is dumped into the sheath 9 where the heavy materials fall towards the mill 10. A fan 14 a its outlet duct 15 which opens into the sheath 9 facing upwards. The fan 14 creates in the sheath 9 an upward flow of air which drives the light materials, and more

  particularly the sheet materials, upwards.

  A first suction duct 16 opens at the top

  the sheath 9 through an orifice 17 (Figure 3).

  A venturi 18 made for example by means of angles or folded sheets forms a constriction in the sheath 9 between the feed orifice 8 and the orifice 17 of the conduit 16. This venturi 18 has the effect of accelerating

  the rising airflow that drives the sheet materials.

  The duct 16 has in its zone adjacent to the sheath 9 an upper surface 19 inclined upwards in the direction of the sheath 9 and a lower surface 19b inclined downwards. Thus heavy products that would be projected into the upper part of the sheath 9 by the action of the mill 10 could not be driven into the conduit 16 since they would hit the surface 19 which would return them either directly in the sheath 9 or on the bottom surface 19 b o they would slip into the

  sheath 9 as shown by the arrow 20.

  The conduit 16 has its other end which enters a second

  vertical sheath 21 for feeding a second mill 22.

  Between these two sheaths, the conduit 16 has a form of venturi

to speed up the flow.

  Inside the sheath 21 and in front of the end of the duct 16 is arranged an endless belt 22 made in the form of a grid and wound on two rollers 23, one of which is a motor for driving the grid 22 in a rotational movement. In this movement, the strand of the belt 22 which receives the flow of air from the conduit 16 moves downwards. The pitch of the grid 22 may for example be of the order of a few centimeters

  and its speed of advancement of the order of 2 meters per second.

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  A box 24 of air collection is disposed in the sheath 21 between the two strands of the grid 22. For clarity, this grid 22 does not have

  shown in Figure 2 which shows in detail the box 24.

  This box has an opening 25 opposite the opening 26 of the end of the conduit 16, on the other side of the grid 22.

  which therefore passes between the openings 25 and 26.

  The box 24 has in one of its vertical faces adjacent to the face in which the opening 25 is formed, another opening connected to a second conduit 27. Thus, the flow of air laden with sheet materials which arrives by the conduit 16, enters the box 24 after being discharged from its sheet materials on the grid 22 and then leaves the box 24 by the second conduit 27. The sheet materials which are pressed against the grid in the area of the opening 25 are dragged down by the movement of this grid and then detach when the portion of the grid on which they are plated out of the air flow. These sheet materials then fall into the sheath 21

  until the mill 22 where they are shredded.

  The conduit 27 opens in a known manner in a cyclone 28 where it emerges through the axial duct 29 after being dusted. Dust

  are recovered at the bottom of the cyclone 28 at the valve 30.

  The dust-free air is then accelerated by a fan 31 driven by a motor 32 to be returned to a third conduit 33 which opens to the upper part of the sheath 9 through an orifice 34 located substantially in

face of the orifice 17 of the conduit 16.

  It is therefore conceivable that, thanks to the device of the invention, is recovered at the outlet of the mill 10 fermentable products that can form humus, at the outlet of the mill 22 non or little fermentable products in the form of sheets such as plastics, paper, fabrics, cardboard, etc., which can then be used to produce combustible granules, and dust at the base

cyclone 28.

  The sheet materials are separated from the fermentable materials at the sheath 9 where they are driven upwards by the rising air flow caused by the fan 14. They are then supported by the transverse air stream coming from the orifice 34 of the conduit 33 and going towards the orifice 17 of the conduit 16

  to be brought to the reception grid 22 which allows their recovery.

  Of course, the invention is not limited to the embodiment described above to which various variants and modifications can be made without departing from the scope of the invention.

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Claims (15)

CLAIMS -   1. Device for the separation of sheet materials in a waste treatment plant, characterized in that it comprises a first substantially vertical sheath (9), means (14) for causing in this first sheath a flow of ascending air, a first duct (16) opening to the upper part of said first duct, and air suction means in said first duct for causing at the upper part of said duct a charged transverse air flow   said sheet materials and penetrating into said first conduit.   2. Device according to claim 1, characterized in that said first sheath forms a venturi (18) below the zone in   which opens said first conduit.   3. Device according to any one of claims 1 and 2,   characterized in that the upper surface (19a) of said first duct is inclined upwards towards the inside of the duct,   in its area adjacent to said sheath.   4. Device according to any one of claims I to 3,   characterized in that the lower surface (19b) of said first duct is inclined downwardly towards the interior of the duct,   in its area adjacent to said sheath.   5. Device according to any one of claims 1 to 4,   characterized in that it comprises means arranged at the end   said first conduit, for stopping said sheet material.   6. Device according to claim 5, characterized in that it comprises a second conduit (27), starting from said stop means, for causing the flow of air freed of said sheet materials to a   cyclone (28) for its dedusting.   7. Device according to claim 6, characterized in that it comprises a third conduit (33) from said cyclone to recycle air dusted.   8. Device according to claim 7, characterized in that said third conduit opens into said first sheath substantially in vis-à-vis said first conduit.   9. Device according to any one of claims 5 to 8,   characterized in that said means for stopping sheet materials comprises a receiving member (22) disposed in a plane transverse to the air flow at the end of said first duct and movable in that plane from the position where it is across said   flow at positions where it is away from this flow. - 7 - 2556246   10. Device for the separation of sheet materials in a waste treatment plant, characterized in that it comprises a first conduit (16), means for driving in this first conduit a charged air flow of said materials in sheets, and a receiving member (22) disposed in a plane transverse to the air flow at the end of said first duct and movable in this plane from the position where it is across said flow to positions where it is away from this flow.   11. Device according to any one of claims 9 and 10,   characterized in that said receiving member is constituted by one of the strands of a grid mat rotating in front of the end of said first conduit.   12. Device according to any one of claims 9 to 11,   characterized in that said receiving member is substantially vertical and is arranged to move downwardly from the position where it is across said flow to positions where it is away from that flow.   13. Device according to any one of claims 9 to 12,   characterized in that an air collection box (24) is disposed behind said receiving member, said box having a first opening (25) substantially opposite said end of the first channel. 14. Device according to claim 13, characterized in that said box has a second opening to which is connected a second conduit (27) for the evacuation of the air freed of said materials. in leaves.   15. Device according to any one of claims 9 to 14,   characterized in that said receiving member is disposed inside a second substantially vertical sheath (21), this second   sheath constituting the supply duct of a second mill (22).