Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
  • B03B9/00—General arrangement of separating plant, e.g. flow sheets
  • B03B9/06—General arrangement of separating plant, e.g. flow sheets specially adapted for refuse
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
  • B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
  • B08B9/027—Cleaning the internal surfaces; Removal of blockages

Definitions

• the present disclosure relates generally to processing of mixed waste to remove non-compost compatible materials. More specifically, the present disclosure proposes a method of processing mixed waste to remove materials such as car batteries, steel objects and glass containers.
• the presently disclosed method will be described hereinafter with reference to this application. However, it will be appreciated that the method is not limited to this application and may be gainfully employed for other purposes.
• MSW Municipal solid waste
• MSW is general waste materials generated by households and business, and contains a vast array of discarded materials, including food wastes, discarded apparel, packaging and paper of various forms, glass and metal objects, plant matter, nappies, household pet wastes, etc.
• MSW may also include recyclables, such as plastic, glass and metal containers, paper and cardboard.
• One method of reducing MSW inputs to landfills, and recovering materials from the MSW stream, is to pre-process to remove valuable materials prior to composting the remaining organic rich fraction. After composting, a refining stage is performed to remove physical contaminants such as glass fragments and plastics.
• the present disclosure provides a method of processing mixed waste, said method comprising:
• At least a portion of the inclined conveyor may be vibratory.
• the vibratory portion may be provided by providing the inclined conveyor with one or more striker axles that have longitudinally and circumferentially spaced apart radially extending formations thereon that engage an underside of a belt of the conveyor to agitate the belt. Material in the mixed waste that has similar height to base dimension
• a cleaning mechanism may be provided for cleaning the conveyor belt.
• the cleaning mechanism may comprise an opposed counter rotating brush roller provided to an upper or drive roller of the inclined conveyor. Waste cleaned from the belt by the cleaning mechanism may be combined with the second proportion.
• the inclined conveyor may comprise a cross-angle.
• the inclined conveyor may comprise side guards to inhibit side spillage of the MSW.
• the inclined conveyor may be inclined at an angle of between 15 to 30 degrees, 20 to 25 degrees or in some embodiments around 22 degrees.
• the inclined conveyor may have a cross-angle of between 0 and 30 degrees. The cross angle may facilitate shedding of material from a main belt of the conveyor to a side belt of the conveyor.
• the inclined conveyor may have a length up to 20 metres, and in some embodiments the conveyor length is between 5 to 15 metres.
• the further processing of the first proportion may include selective removal of one or more of the items selected from the group consisting of: lead acid batteries, ferrous materials, intact glass, aluminium, plastic containers, e-waste, and
• Light ferrous materials may be removed from the first proportion by passing the first proportion through a magnetic field.
• Lead acid batteries may be manually removed from the first proportion.
• Heavy ferrous materials may be manually removed from the first proportion.
• Intact glass may be manually removed from the first proportion.
• Plastic containers may be manually removed from the first proportion.
• E- waste may be manually removed from the first proportion.
• Organics/nappies may be manually removed from the first proportion.
• Aluminium may be electro-mechanically removed from the first proportion, such as by eddy current. Material not removed during the further processing of the first proportion may be sent to landfill.
• a plurality of the inclined conveyors may be provided in series.
• a feed mechanism may uniformly meter the MSW onto the inclined conveyer.
• the feed mechanism may comprise a vibratory feeder.
• An excavator, front-end-loader or similar machine may load the MSW into the feed mechanism. .
• a processing plant for processing mixed waste comprising:
• an inclined conveyor for receiving the mixed waste from the feeding mechanism, the conveyor having an upward incline in the direction of belt travel, such that the mixed waste is separated into a first proportion that rolls backward due to the incline and a second proportion that continues in the direction of belt travel;
• At least a portion of the inclined conveyor may be vibratory.
• the vibratory portion may be provided by providing the inclined conveyor with one or more striker axles that have longitudinally and circumferentially spaced apart radially extending formations thereon that engage an underside of a belt of the conveyor to agitate the belt. Material in the mixed waste that has similar height to base dimension
• a cleaning mechanism may be provided for cleaning the conveyor belt.
• the cleaning mechanism may comprise an opposed counter rotating brush roller provided to an upper or drive roller of the inclined conveyor. Waste cleaned from the belt by the cleaning mechanism may be combined with the second proportion.
• the inclined conveyor may comprise a cross-angle.
• the inclined conveyor may comprise side guards to inhibit side spillage of the MSW.
• the inclined conveyor may be inclined at an angle of between 15 to 30 degrees, 20 to 25 degrees or in some embodiments around 22 degrees.
• the inclined conveyor may have a cross- angle of between 0 and 30 degrees.
• the cross angle may facilitate shedding of material from a main belt of the conveyor to a side belt of the conveyor.
• the inclined conveyor may have a length up to 20 metres, and in some embodiments the conveyor length is between 5 to 15 metres.
• a plurality of the inclined conveyors may be provided in series.
• a feed mechanism may be provided upstream of the inclined conveyor to uniformly meter the MSW onto the inclined conveyer.
• the feed mechanism may comprise a vibratory feeder.
• Figure 1 is a schematic illustration of a processing plant for processing MSW in accordance with an embodiment of the presently disclosed MSW processing method
• FIG 2 is a perspective view of a vibratory feeder and an inclined conveyor of the processing plant of Figure 1;
• FIG 3 is a perspective view of the inclined conveyor of Figure 2, shown with the conveyor belt removed;
• Figure 4 is an enlarged view of the circled portion of Figure 3;
• Figure 5 is a side elevational view of the vibratory feeder and inclined conveyor of Figure 2.
• Figure 6 is an enlarged view of the circled portion of Figure 5.
• FIG. 1 to 6 there is shown a processing plant 10 for processing mixed MSW 100.
• the plant 10 includes an inclined (or "bounce") conveyor 12 having an upward incline of around degrees in the direction of belt travel.
• the conveyor 12 has a main belt 12a with a length of around 7 metres and a width of around 1.8 metres.
• the conveyor 12 also comprises a side belt 12b of the same length as the main belt 12a, but having a lesser width of around 400mm.
• the conveyor 12 comprises an adjustable sub- frame 12c allowing for the conveyor incline to be set at a desired gradient of between 20 and 24 degrees in the direction of belt travel.
• the sub-frame 12a also allows a cross angle of the main belt 12a to be set at a desired angle of between 0 and 22 degrees.
• the conveyor 12 includes several striker axles 14 that have longitudinally and circumferentially spaced apart radially extending formations 16 thereon that engage an underside of the conveyor belt to agitate the belt.
• the striker axles 14 are spaced apart by around 600mm and are individually driven.
• the rotational direction of the striker axles 14 is opposite to the direction of belt travel.
• the speed of the conveyor belt is adjustable, as is the rotational speed of the striker axles 14.
• toppling of relatively high centre of gravity materials down the incline may be inhibited by the presence of relatively "flat" materials on belt. Accordingly, especially when the main belt 12a is set to have a cross-angle, the action of the striker axles 14. facilitates toppling of relatively high centre of gravity materials onto the side belt 12b, where such materials may have a clearer path down the incline.
• the conveyor 12 also comprises side guards 18 to inhibit side spillage of the MSW.
• a cleaning mechanism in the form of an opposed, under-slung, counter rotating, self-adjusting cleaning brush roller 1 , is provided to an upper drive roller of the inclined conveyor for cleaning the conveyor belt. Waste cleaned from the belt by the cleaning mechanism 19 may be combined with the second proportion.
• an excavator, front-end-loader or similar machine 20 loads unscreened MSW into a feed mechanism, in the form of a vibratory feeder 30, which uniformly meters the MSW onto the conveyer 12.
• the upward incline and vibration of the conveyor 12 facilitates "flat' materials with a relatively low centre of gravity progressing to the top discharge end 12d of the conveyer, while heavy or round objects with higher centre of gravity already effected by the belt incline are pushed past their point of balance by the localised elevation of the main belt 12a and momentum imparted by the striker axles 14 under the main belt.
• the momentum, incline and further impacts by striker axles 14 continue the toppling backwards of the relatively high centre of mass objects for discharge at the bottom end 12d of the conveyer, whilst the rest of the MSW progresses to the top discharge end 12e of the conveyor.
• the MSW is separated into a first proportion that rolls backwards and a second proportion that continues in the direction of belt travel.
• the first proportion generally comprises lead-acid batteries and other non-compost compatible materials, whilst the second proportion contains a high proportion of compost compatible materials.
• the second proportion is directed to a compost producing system 40 for further processing to produce compost.
• the second proportion may be fed directly to the compost producing system 40 or fed to the compost producing system 40 after further pre-processing to increase its organic content.
• the non-compost compatible first proportion is directed to a recycling system 50 and is further processed to remove lead acid batteries, ferrous materials, intact glass, aluminium, and organics/nappies.
• Light ferrous materials are removed from the first proportion by passing the first proportion through a magnetic field.
• Lead acid batteries, heavy ferrous materials, intact glass and organics/nappies and bagged materials are manually removed from the first proportion.
• Aluminium cans are electro-mechanically removed from the first proportion by eddy current. Material not removed during the further processing of the first proportion is sent to landfill.
• the above described processing plant 10 and method have been found to reliably maintain the second proportion of MSW that passes the conveyor 12 substantially free from lead acid batteries, such that this second proportion is rendered compliant with the relevant State regulations for compost.
• the resulting lead concentrations in the second proportion have also been found to be lower than those resulting from pre-treatment systems that have been used in the past.
• Other benefits provided by the above described processing plant 10 and method include:
• PET and other round plastic containers tend to roll backwards down the incline of the conveyor 12. These containers can be recovered from the first proportion for recycling or sale.
• Aluminum round containers such as aluminium cans, tend to roll backwards down the incline of the conveyor 12.
• the aluminium containers tend to remain clean, and can be recovered from the first proportion by an electro-mechanical process (eg. eddy current) for recycling or sale.
• an electro-mechanical process eg. eddy current
• E-waste such as small NiCd and alkaline batteries, and electronic components from televisions to telephones, appears to be more concentrated in the first proportion of the MSW that rolls backwards down the incline of the conveyor 12. Reduction in e-waste in the second proportion facilitates a reduction in heavy metal contamination in compost produced from the second proportion that passes the conveyor 12.
• E-waste may be manually removed from the first proportion for further processing
• Plastic containers may be manually removed from the first proportion for further processing, recycling or sale; and/or

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• Processing Of Solid Wastes (AREA)

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Cited By (1)

Citations (2)

• 2013
  • 2013-03-27 WO PCT/AU2013/000314 patent/WO2013142904A1/fr not_active Ceased
  • 2013-03-27 AU AU2013239323A patent/AU2013239323A1/en not_active Abandoned

Patent Citations (2)

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