EP2205346B1 - Household waste processing device and system - Google Patents

Abstract

The invention relates to a household waste mixing device (1) comprising a drum (2) rotating about an axis (X2) in a mixing direction (M), said mixer comprising two drum plates (6, 7) and a belt (4) of cylindrical general shape around the mixing axis. The device according to the invention is noteworthy in that it also comprises mixing spades (13, 14) extending approximately parallel to the axis, inside the belt, at least one spade (14) comprising teeth capable of tearing bin liners. The bin liners may be sucked away through a chimney (19) for conversion into a gas for producing electricity. Such a device is used to extract value from waste and avoid the need to open bin liners before the drum is loaded.

Description

The present invention relates to a device and a system for treating and recovering household waste. It relates in particular to the valuation of garbage bags.

There are processes for recovering household waste, including sorting and then converting organic waste into compost. However, garbage is usually contained in garbage bags, resistant and difficult to open. Thus, it takes a lot of time for operators to open the bags and release the trash itself and, if necessary, sort the contents before a subsequent transformation. A device according to the state of the art is disclosed in US-A-5,427,947 .

A first objective of the invention is to propose a solution to facilitate the sorting operations, in particular the opening of the bags.

A second objective of the invention is also to provide a system for improving the recovery of household waste, including that of bags.

According to the invention, such a device is a mixing device for household waste comprising a drum comprising an interior volume defined by two generally disk-shaped sponges arranged transversely to the mixing axis, at a distance from each other according to said axis, and a generally cylindrical belt connecting the edges of said eardrums, characterized in that it further comprises mixing shovels protruding on an inner surface of the belt, at least one of said shovels comprising, on a distant ridge of the belt, a shredding toothing of garbage bags.

Preferably, each shovel extends from one eardrum to the other. Preferably, each shovel is disposed substantially parallel to the mixing axis. The shovels may further be provided to radially project on the inner surface of the belt.

The toothing advantageously extends over a major part of the length of the shovel, from a drum. The toothing preferably has a transverse inclination to the drum, in a direction corresponding to the mixing direction. Thus, during mixing, it comes to flee in the bags that would be in its path, to tear them.

The device may comprise an even number of shovels, and a shovel equipped with a toothing be arranged alternately between two shovels without toothing. Thus, a series of shovels is more particularly affected to the opening of the bags. The other series of shovels, which is not likely to hang some waste, is particularly suitable for mixing. The shovels with teeth preferably each have a substantially constant height and substantially between 6 and 9 percent of the inner diameter of the drum. The shovels without teeth preferably each have a substantially constant height and substantially between 9 and 13 percent of the inner diameter of the drum.

The toothing may be made of a plate whose free edge comprises a cutout in the form of successive triangles, fixed on the peak of the shovel by an edge opposite the free edge.

In such a device, one of the eardrums can be assigned to the supply of garbage in the drum, in the vicinity of the axis, and a hatch provided for the evacuation of the mixture can be arranged in the opposite tympanum, in the vicinity immediate area of the belt, said drum further comprising a coil extending along the inner surface of the belt from an end of a first shovel, near the entrance eardrum, away from the input eardrum in the direction of the tympanum drain while approaching a shovel immediately adjacent in the direction of mixing. The device may comprise several turns, each between two adjacent shovels, the hatch may be arranged between two shovels, in the immediate vicinity of the neighboring shovel in the mixing direction and the corresponding turn may extend to the emptying drum, then that or the other turns meet a respective shovel at a distance from said discharge drum. A turn may be formed of a sheet fixed perpendicularly to the inner face of the belt, and has a height, preferably constant, between 0.6 and 1 times the height of a shovel.

The device may further comprise suction means for inorganic residues and fines.

A system for recovering household waste according to the invention is particularly remarkable in that it comprises a mixing device according to the invention equipped with such suction means, and in that it further comprises a device for gasifying waste and fine aspirates.

Such a system advantageously comprises a device for producing electricity from waste and gasified fines.

• La figure 1 est une vue partiellement arrachée d'un dispositif selon l'invention ;
• La figure 2 est une vue en coupe d'une pelle simple pour le dispositif de la figure 1 ;
• La figure 3 est une vue partielle, en perspective et en coupe, d'une pelle dentée pour le dispositif de la figure 1 ; et,
• La figure 4 est une vue schématique d'un système de traitement des ordures ménagères incluant un dispositif selon l'invention.

Other features and advantages of the invention will become apparent from the description below, relating to non-limiting examples illustrated in the accompanying drawings in which:

• The figure 1 is a partially cutaway view of a device according to the invention;
• The figure 2 is a sectional view of a simple shovel for the device of the figure 1 ;
• The figure 3 is a partial view, in perspective and in section, of a toothed shovel for the device of the figure 1 ; and,
• The figure 4 is a schematic view of a garbage treatment system including a device according to the invention.

As particularly illustrated at figure 1 , a device 1 according to the invention comprises a mixing drum 2. The drum is designed to receive garbage to be treated, homogenize and mix with suitable treatment products. The drum rests on rollers 3 which serve to support and rotate it around a drum axis X2. The mixture is made in a chosen direction of rotation, illustrated by an arrow M.

In the example shown, the drum axis X2 is substantially horizontal. The drum 2 defines an interior space intended to receive the garbage. This interior space is defined by a substantially cylindrical belt 4 and two eardrums 6.7. The belt 4 is substantially of revolution about the axis X2. The eardrums each have substantially the general shape of a disc perpendicular to the axis X2, said two eardrums being spaced from each other along the axis X2 and their peripheral edges being interconnected by the belt 4.

The device of the figure 1 further comprises a hopper 10 provided for receiving refuse intended to be processed in the device. A supply screw 8 is disposed at the bottom of the hopper 10. This screw is of the worm type; it is substantially coaxial with the drum 2, that is to say that the supply is made through an input tympanum 6 among the two drum sponges 6,7, substantially in the center of the input tympanum 6.

The device also comprises a hatch 9 for evacuation of garbage contained in the drum. This trap is formed in the other tympanum, said discharge drum 7. A hopper 11 and a worm 12 collect garbage at the exit of the hatch 9, and then transport them.

To ensure mixing inside the drum 2, it comprises shovels 13, 14 and 15,16 turns.

Each shovel extends from one eardrum to the other, substantially longitudinally, that is to say substantially parallel to the axis X2. Each shovel extends radially from an inner surface of the belt, towards the axis X4. The shovels are regularly distributed around the X2 axis. In the example illustrated, the shovels are eight in number. The shovels are in addition of two categories; the shovels of one are equipped with teeth while others do not. In the illustrated example, there are four toothed shovels 14 arranged alternately between two toothless shovels 13.

Each shovel has a hollow cross section substantially symmetrical on both sides of a respective radial and longitudinal plane P (see FIG. figure 3 ). The section narrows as one moves away from the belt 2, first slowly, then more quickly by a triangular tip forming a crest of the shovel. The teeth 17 are formed in a plate 18 fixed on one of the sides of the tip, so that it is inclined relative to the respective radial plane P, in the mixing direction M. The teeth 17 are formed in a free edge of the plate 18, so that that they exceed beyond the crest of the shovel. In the illustrated example, the teeth extend over the entire depth L17 of the plate protruding beyond the crest of the shovel. The plate extends longitudinally from the input tympanum 6 over a distance L18 greater than half the length L2 of the drum.

Each turn 15,16 extends along the inner surface of the belt 2 from one end of a first shovel 13,14, near the input eardrum 6, away from the entrance eardrum towards the drain drum 7 while approaching a shovel 14,13 immediately adjacent in the direction of mixing M. A turn 15,16 is disposed between each shovel and each of its immediate neighbors.

Current turns 15 stop at a distance L15 from the discharge tympanum 7. The current turns 15 form with an transverse plane, for example with a tympanum, an angle A15.

Preferably, L2 - L15 <L18 is selected.

In the illustrated example, the hatch 9 is disposed just before a shovel, here a shovel 14, by traveling along the belt in the direction of mixing M. A special turn 16 is disposed between the shovel that precedes the shovel and this shovel toothed. This special turn 16 extends substantially from the junction of the previous shovel 13 with the input tympanum 6, until the junction of the corresponding toothed shovel with the emptying drum 7, in the immediate vicinity of the hatch 9. Thus , the special turn extends from one tympanum to the other, and also extends from one shovel to the other of the two shovels flanking the hatch 9.

The device of the figure 1 further comprises means for generating a stream of air within the drum, adapted to entrain the finest particles and the low density waste and / or having a strong hold in the wind, in particular the sheets or the plastic bags . Means for evacuating this air and what it carries with it, here a chimney 19, are also provided.

An airlock 21 is provided upstream of the drum 2 and around the screw 8, downstream of the hopper 10. Another lock, not shown, is also provided downstream of the drum and around the screw 12. These airlocks make it possible to avoid that loading and / or unloading part of the garbage, the most volatile can escape and spread out of the device 1.

The operation of the device 1 will now be described.

The household waste is transported to the device 1 and then discharged into the hopper 10. From there, the garbage is entrained by the worm 8 into the drum 2 where they penetrate substantially in the middle of the input eardrum 6.

The drum being rotated in the direction M provided for mixing, the waste is stirred by the shovels 13,14 as they are introduced and during their presence in the drum 2. Products are added during the brewing to accelerate the stabilization and disinfection of garbage. The plastic bags, in particular, are torn by the teeth 17 of the toothed shovels 14; the garbage they still contain is released and comes to mix with others. During mixing, the remains of plastic bags, generally lighter than the garbage itself, as well as the fine particles, are entrained in the air stream, and discharged through the stack 19 to be specifically treated.

The turns 15, 16, when the drum is rotating in the direction of mixing M, tend to return the garbage to the input eardrum 6, which has the effect of mixing more homogeneously with newly re-entering garbage. The homogeneity of the final mixture is thus improved.

When the mixing is complete, the drum is then rotated in the opposite direction of M. In this direction of reverse rotation, the turns 15, 16 tend to return the garbage to the emptying drum 7, that is to say say in particular to the hatch 9. In particular, the turn 16 which extends to the discharge drum 7, in the immediate vicinity of the hatch, allows to bring the garbage up behind the hatch 9, which facilitates their evacuation.

To facilitate mixing, the drum 2 is provided such that its length L2 measured along the mixing axis X2 is smaller than its inside diameter D2.

A device 1 according to the invention, in particular as represented in FIG. figure 1 can be integrated in a system 30 for recycling household waste as schematically illustrated in the figure 4 . In addition to the device 1, illustrated by the drum 2, the system 30 comprises a digester 31, a device 32 for gasification of the waste entrained by the air stream, that is to say in particular the pieces of plastic bags, and a power plant 33 able to produce electricity from the gases thus produced.

Beyond the drum 2, the garbage can then be brought by the worm 12, into the digester 31. The digestion of this garbage can stabilize them. They can then be sorted further, manual, in conditions of improved comfort for operators.

Garbage extracted from the digester, possibly after the additional sorting, form a soil 34 which can be immediately reused, especially in agriculture.

Furthermore, the plastic waste and the fine extracts of the drum 2 through the chimney 19, are directed to the gasification device 32 to be converted into a gas that can be used by the plant 33 to produce electricity. This electricity can be used by the household waste treatment system 30 for its own operation. The surplus electricity produced is advantageously supplied to third parties, individuals or businesses.

• D2 = 4m50
• L2 = 3m50
• A15 = 49,7°
• H13 = 0,5m
• H14 = 0,3m
• L15 = 0,6m
• A17 = 45°
• L17=0,1m
• L18 = 3m

In a preferred embodiment of the drum 2, its dimensions are approximately:

• D2 = 4m50
• L2 = 3m50
• A15 = 49.7 °
• H13 = 0.5m
• H14 = 0.3m
• L15 = 0.6m
• A17 = 45 °
• L17 = 0.1m
• L18 = 3m

Other preferred, non-limiting embodiments may have dimensions that vary within a range of about 10% plus or minus the above values.

Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

Thus, the mixing axis can be inclined towards the discharge drum, to facilitate the emptying of the drum.

Claims (14)

1. A household waste mixing device (1) comprising a drum (2) rotating around a mixing axis (X2) and means (3) for driving said drum in rotation in a mixing direction (M), said drum comprising an inner volume defined by two drum plates (6, 7) in the general shape of discs arranged transversely to the mixing axis, at a distance (L2) from each other along said axis, and a generally cylindrical belt (4) connecting the edges of said drum plates, the device comprising mixing spades (13, 14) protruding over an inner surface of the belt, characterized in that at least one of said spades (14) comprises, on a crest remote from the belt, a toothing (17,18) for tearing bin liners.
2. The device according to claim 1, characterized in that the toothing extends over a majority (L17) of the length of the spade (14), from a drum (6).
3. The device according to claim 1 or 2, characterized in that the toothing has an incline (A17) transverse to the drum, in a direction corresponding to the mixing direction (M).
4. The device according to one of the preceding claims, characterized in that it comprises an even number of spades, and in that a spade (14) equipped with a toothing is alternatingly arranged between two spades (13) without a toothing,
5. The device according to one of the preceding claims, characterized in that the spades equipped with a toothing each have a substantially constant height (H14) that is substantially between 6 and 9% of the inner diameter (D2) of the drum.
6. The device according to one of the preceding claims, characterized in that the spades without a toothing each have a substantially constant height (H13) that is substantially between 9 and 13 percent of the inner diameter (D2) of the drum.
7. The device according to one of the preceding claims, characterized in that the toothing is formed in a plate (18) whereof one free edge comprises a cutout in the shape of successive triangles, fastened on the crest of the spade (14) by an edge opposite the free edge.
8. The device according to one of the preceding claims, characterized in that a drum plate (6) is allocated to providing waste in the drum, near the axis, and in that a hatch (9) for discharging the mixture is formed in the opposite drum plate (7), in the immediate vicinity of the belt (4), said drum also comprising a coil (15, 16) extending along the inner surface of the belt from one end of a first blade, close to the input drum plate (6), while moving away from the input drum plate towards the emptying drum plate while coming closer up to an immediately adjacent spade along the mixing direction (M).
9. The device according to claim 8, characterized in that it comprises several coils (15, 16), each between two adjacent spades, in that the hatch is arranged between two spades (13, 14), in the immediate vicinity of the adjacent spade (14) in the mixing direction, and in that the corresponding coil (16) extends up to the emptying drum plate (7), the other coil(s) (15) rejoining a respective spade at a distance (L15) from said emptying drum plate (7).
10. The device according to claim 8 or 9, characterized in that a coil is formed from a sheet fastened perpendicularly on the inner face of the belt, and with a height between 0.6 and 1 times the height of a spade.
11. The device according to one of the preceding claims, characterized in that it also comprises suction means (19) for non-organic residue and fines.
12. the device according to one of the preceding claims, characterized in that each spade extends substantially parallel to the mixing axis.
13. A system (30) for extracting value from household waste, characterized in that it comprises a device (1) according to the preceding claim, and in that it also comprises a device (32) for gasifying suctioned waste and fines.
14. The system according to the preceding claim, characterized in that it also comprises a device (33) for producing electricity from gasified waste and fines.

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