Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/02—Cleaning by the force of jets or sprays
  • B08B3/022—Cleaning travelling work
• • 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
  • B03B9/04—General arrangement of separating plant, e.g. flow sheets specially adapted for furnace residues, smeltings, or foundry slags
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
  • B07B1/12—Apparatus having only parallel elements
  • B07B1/14—Roller screens
  • B07B1/15—Roller screens using corrugated, grooved or ribbed rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B13/00—Grading or sorting solid materials by dry methods, not otherwise provided for; Sorting articles otherwise than by indirectly controlled devices
  • B07B13/14—Details or accessories
  • B07B13/16—Feed or discharge arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J1/00—Removing ash, clinker, or slag from combustion chambers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J2900/00—Special arrangements for conducting or purifying combustion fumes; Treatment of fumes or ashes
  • F23J2900/01001—Sorting and classifying ashes or fly-ashes from the combustion chamber before further treatment
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J2900/00—Special arrangements for conducting or purifying combustion fumes; Treatment of fumes or ashes
  • F23J2900/01005—Mixing water to ash

Definitions

• the invention relates to an arrangement and a method for the first sorting of waste slag from a waste incineration furnace, for example in a district heating plant.
• First sorting is performed for the separation at an early stage of fine, non-magnetic pieces of waste slag from fine and coarse magnetic pieces of waste slag and coarse, non-magnetic pieces of waste slag prior to the subsequent recovery processes.
• Waste slag remains after the incineration of waste in a waste incineration furnace.
• the waste slag contains large quantities of metallic and non-metallic materials, which can be recovered with modern technology for re-use as raw materials, for example in steelworks, or as a filling material in building work.
• the metallic pieces of waste slag consist of everything from very small objects, such as nails, to larger metal objects, such as automobile silencers, gearboxes and body components.
• the waste slag is quenched with water, in conjunction with which fresh or wet slag is obtained.
• the quenching water initiates a chemical process in this way, in which ash and other impurities slowly become burnt onto the surfaces of the metallic pieces of waste slag.
• a coating of ash and other particles of slag which is very difficult to remove, will have formed on the metallic pieces of waste slag.
• vibrating screens and drum sieves are used among other things in conjunction with subsequent manual sorting to remove fine and coarse pieces of waste slag and to separate non-magnetic pieces of waste slag from magnetic pieces of waste slag prior to subsequent recovery processes.
• a problem with today's previously disclosed sorting facilities is that the separation of fine, non-magnetic pieces of waste slag takes place at a relatively late stage in the sorting chain, because as a general rule the waste slag first passes through at least one coarse sieve. Early separation of the fine, non-magnetic pieces of waste slag is desirable from the point of view of handling, as this material can be transported away more rapidly and dealt with as a filling material in conjunction with building work, for example.
• Another problem with the previously disclosed technology is that it is not possible to process fresh or wet slag immediately after incineration in the above-mentioned previously disclosed sorting facilities, because the wet waste slag adheres to and blocks the screens and the drum sieves in the sorting facility.
• the waste slag thus requires to be kept in intermediate storage for a time, usually for about a month, to enable the quenching water to drain away and to give the waste slag a chance to dry out.
• a large proportion of the recovery potential is lost during intermediate storage, however, as a consequence of the aforementioned coating of ash and other slag products on the metallic pieces of waste slag becoming burnt on.
• the invention makes available an arrangement for the first sorting of waste slag from a waste incineration furnace, comprising a motor- driven roller grating with a number of rollers for the purpose of permitting fine pieces of waste slag to pass through essentially vertically and for the onward transport of coarse pieces of waste slag essentially horizontally, where the aforementioned roller grating exhibits an intake end and- a discharge end.
• the invention is characterized in particular in that:
• a first belt conveyor situated beneath the roller grating, and so arranged as to collect fine pieces of waste slag falling through the roller grating and to transport these to a discharge end situated adjacent to the discharge end of the roller grating;
• a second belt conveyor exhibiting an intake end situated beneath the discharge end of the roller grating and so arranged as to collect coarse pieces of waste slag falling from the discharge end of the roller grating, where the intake end of the aforementioned second belt conveyor is also situated at a distance from the discharge end of the first belt conveyor such that a slag passage for fine pieces of waste slag is present between the discharge end of the first belt conveyor and the intake end of the second belt conveyor;
• a rotating roller situated at the intake end of the second belt conveyor, and equipped with a magnet so arranged as to attract fine pieces of magnetic scrap from the fine pieces of waste slag falling through the slag passage and to carry these to the second belt conveyor.
• a liquid washing device arranged for rinsing the waste slag is installed adjacent to the intake end of the second belt conveyor.
• a corresponding liquid washing device is installed adjacent to the discharge end of the roller grating.
• the liquid washing device is installed adjacent to the intake end of the second belt conveyor and the discharge end of the roller grating.
• the liquid washing device preferably comprises one or more rinsing nozzles, through which liquid washing takes place by means of pressure within the range of 2-20 bar, and preferably 5-10 bar.
• the liquid washing device is situated above the intake end of the second belt conveyor and the discharge end of the roller grating.
• a chute for coarse items of waste slag extends from the discharge end of the roller grating to a position above the intake end of the second belt conveyor.
• the magnet in the previously mentioned rotating roller is preferably a permanent magnet, which is executed as an essentially solid jacket on the rotating roller.
• the magnet in the rotating roller consists of an electromagnet.
• the rate of feed of the second belt conveyor exceeds the rates of feed of the roller grating and the first belt conveyor.
• the aforementioned fine pieces of waste slag preferably exhibit a greatest cross-sectional width of up to 50 mm, and preferably up to 40 mm.
• the aforementioned coarse pieces of waste slag exhibit a cross-sectional width exceeding 40 mm.
• a slag collection point for fine, non-magnetic pieces of waste slag is situated essentially directly beneath the slag passage.
• a third belt conveyor is situated beneath the slag passage for the onward transport of fine, non-magnetic pieces of waste slag.
• This third belt conveyor is preferably arranged essentially at right angles to the first belt conveyor.
• the invention also relates to a method for the first sorting of waste slag from a waste incineration furnace, where fine pieces of waste slag are initially separated from coarse pieces of waste slag by means of a motor-driven roller grating with a number of rollers together with an intake end and a discharge end, in conjunction with which the aforementioned fine pieces of waste slag pass essentially vertically through the roller grating, while coarse pieces of waste slag are transported onwards essentially horizontally on the roller grating to its discharge end.
• the method is characterized essentially:
• the waste slag is rinsed with water from a liquid washing device installed adjacent to the intake end of the second belt conveyor.
• the waste slag is rinsed with liquid from a liquid washing device installed adjacent to the discharge end of the roller grating.
• the waste slag is rinsed with liquid from a liquid washing device installed adjacent to the intake end of the second belt conveyor and the discharge end of the roller grating.
• Rinsing takes place preferably via one or more rinsing nozzles by means of a water pressure within the range of 2-20 bar, and preferably 5-10 bar.
• fine, non-magnetic pieces of waste slag are collected at a slag collection point situated essentially directly beneath the slag passage.
• fine, non-magnetic pieces of waste slag are collected and transported onwards on a third belt conveyor situated beneath the slag passage.
• Fig. 1 shows a schematic side view of an arrangement for the first sorting of waste slag in accordance with a first embodiment of the invention
• Fig. 2 shows an enlarged side view of the area around the slag passage between the first and the second belt conveyors
• Fig. 3 shows a schematic side view of a second embodiment of the invention, where a third belt conveyor is situated beneath the slag passage for the onward transport of fine, non-magnetic pieces of waste slag, and where a feed belt conveyor is situated at the intake end of the roller grating.
• DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS the reference designation 1 is used generally to denote an arrangement for the first sorting of waste slag in accordance with a first embodiment of the invention.
• the waste slag consists of residual products from the incineration of waste in a waste incineration furnace (not shown) and contains ash mixed with metallic objects which have not melted in the course of incineration and non- metallic unburned objects such as gravel and concrete residues.
• the metallic pieces of waste slag consist of everything from very small objects such as nails, to larger metal objects such as automobile silencers, gearboxes and body components.
• the arrangement in accordance with the invention for sorting is situated with advantage in proximity to the waste incineration furnace, either directly adjacent to it or at a distance from it such that it is accessible to slag waste transport by lorry or other means of transport within one or a few hours after the waste slag has left the incineration furnace.
• the waste slag is quenched with water. This initiates a chemical process in which ash and other impurities slowly become burnt onto a coating on the surfaces of the pieces of metallic slag. After storage for a relatively short period, a coating of ash and other particles of slag, which is very difficult to remove, will have formed on the aforementioned pieces of metallic slag, for which reason rapid transport to the first sorting facility makes further processing easier.
• the waste slag is first fed onto a roller grating 2, as indicated by the arrow 3 on the right-hand side of Fig. 1. Feeding can take place directly by unloading from a lorry or via a feed conveyor, which will be described later with reference to the alternative embodiment of the invention shown in Fig. 3.
• the roller grating 2 is equipped with a number of rollers 4, which, in the illustrative example, are ten in number.
• the rollers 4 are supported parallel with one another about shafts 5.
• the rollers 4 are illustrated most clearly in the enlarged, cut-away side view in Fig. 2, where it can also be clearly seen that the rollers 4 are provided with projecting carrier flanges 6.
• the carrier flanges 6 are executed in such a way that they convey the waste slag in the direction of feed of the roller grating 2, as indicated by the arrow 7.
• the rollers 4 are driven in synchronized fashion by a motor, not shown here, foe example via a chain transmission (not shown) in a previously disclosed fashion.
• the rollers 4 are also positioned at a distance from one another such that fine pieces of waste slag 8 pass essentially vertically between the rollers 4, while coarse pieces of waste slag 9, as a consequence of their coarse dimensions, are unable to pass between the rollers and are transported onwards horizontally on the roller grating 2 from its intake end 10 to its discharge end 11.
• fine pieces of waste slag_ is used here to denote objects whose greatest cross-sectional width amounts to 40 mm, while the expression coarse pieces of waste slag denotes objects whose cross-sectional width exceeds 40 mm. It must also be appreciated, however, that these dimensional details can vary upwards or downwards to a certain extent depending on the requirements that are set in respect of sorted material for recovery. Thus, for example, the aforementioned fine pieces of waste slag 8 can exhibit a maximum cross-sectional width of 50 mm, in conjunction with which coarse pieces of waste slag 9 consequently exhibit a cross-sectional width exceeding 50 mm.
• the discharge end 14 of the first belt conveyor 13 is, as can be appreciated from Figs. 1 and 2, situated adjacent to the discharge end 11 of the roller grating 2 and directly beneath it.
• the vertical distance between the first belt conveyor 13 and the roller grating 2 is relatively small and corresponds essentially to the vertical thickness of the belt conveyor 13.
• the first belt conveyor 13 is equipped in a conventional fashion with an endless belt web 16, which runs around two rotating rollers 17 and 18.
• the first belt conveyor 13 is driven by an electric motor 19 connected to one of the rotating rollers 18, as illustrated in Fig. 1.
• Each of the rotating rollers 17, 18 is mounted for this purpose about its own axle 21 and 22 in a longitudinal beam framework 20.
• a second belt conveyor 24 exhibits an intake end 25 situated beneath the discharge end 11 of the roller grating 2.
• the second belt conveyor 24 is so arranged in this way as to collect coarse pieces of waste slag 9, which fall from the discharge end 11 of the roller grating 2 via a chute 26 inclined downwards at an angle, which chute extends from the discharge end 11 of the roller grating 2 to a position immediately above the intake end 25 of the second belt conveyor 24.
• the intake end 25 of the second belt conveyor 24 is also situated at a distance from the discharge end of the first belt conveyor 13 such that a slag passage 27 for fine pieces of waste slag 8 is present between the discharge end of the first belt conveyor 13 and the intake end 25 of the second belt conveyor 24.
• the second belt conveyor 24 is conventionally constructed with an endless belt web 28, a beam framework 29 in which a rotating roller 30 is mounted at the intake end 25 by means of a shaft 31, and a rotating roller 32 is mounted at the discharge end
• the second belt conveyor 24 is equipped with a number of carrier projections
• the carrier projection 23 runs in a transverse direction across the width of the second belt conveyor 24 and as such extends at right angles to the plane of the Figures.
• the magnet 36 consists of a permanent magnet designed as an essentially solid jacket around the shaft 31, as may best be appreciated from Fig. 2.
• the magnet 36 instead consists of an electromagnet .
• the three arrows 38 in Fig. 2 illustrate how the fine pieces of magnetic scrap 37 are attracted by the magnet 36 and are carried on the second belt conveyor 24, whereas fine, non ⁇ magnetic pieces of waste slag 39 fall unobstructed through the slag passage 27 and are collected at a slag collection point 40 situated essentially directly beneath the slag passage 27.
• a considerable advantage over previously disclosed technology is gained in this way, because the fine, non-magnetic pieces of waste slag 39 can be dealt with at a very early stage in the sorting procedure to permit their reuse, for example as a filling material in building work.
• the second belt conveyor 24 is inclined upwards at an angle such that the discharge end 33 is situated at a higher level than the intake end 25.
• the angle ⁇ 18°.
• coarse pieces of waste slag 9 - both magnetic and non-magnetic - and fine pieces of magnetic scrap 37 are fed towards the discharge end 33 of the second belt conveyor 24, as indicated by the arrow 41.
• the rate of feed of the second belt conveyor 24 in this case exceeds the rates of feed of the rotating roller 2 and the first belt conveyor 13, in conjunction with which effective onward transport is achieved without the risk of accumulations of waste slag at the intake end 25 of the second belt conveyor 24.
• the objects 9, 37 then fall into a container 42, which is shown schematically in Fig. 1.
• the container 42 in the illustrative embodiment is situated in a separate space 43, which is segregated from the slag collection point 40 by means of a dividing wall 44.
• the separate space 43 is also situated at a higher level than the slag collection point 40.
• a subsequent sorting facility not shown
• Final sorting and separation of coarse, non-magnetic items of waste slag 9 and, as a rule, sorting of coarse, magnetic pieces of waste slag 9 and fine, magnetic pieces of waste slag 37 take place in the subsequent sorting facility, which is not shown here.
• the aforementioned subsequent sorting facility can be situated in the separate space 43, in which case the container 42 shown in Fig. 1 is accordingly replaced by the subsequent sorting facility.
• the waste slag is rinsed with liquid from a liquid washing device 45 installed adjacent to the intake end 25 of the second belt conveyor 24 and to the discharge end 11 of the roller grating 2.
• the liquid washing device 45 can be attached only adjacent to the intake end 25 of the second belt conveyor 24.
• the liquid washing device 45 can instead be attached only adjacent to the discharge end 11 of the roller grating 2.
• the liquid consists preferably of clean water, but as an alternative it can also contain cleaning additives of various kinds or may consist entirely of a cleaning agent.
• the liquid washing device 45 in the illustrative embodiment is equipped with four washing nozzles 46, via which liquid washing takes place at a pressure within the range 2-20 bar, and preferably 5-10 bar.
• the washing nozzles 46 are mounted on an elongated carrier arm 47, which is fixed or adjustably attached above the intake end 25 of the second belt conveyor 24 and the discharge end 11 of the roller grating 2.
• the washing nozzles are provided in the illustrative embodiment with a pressurized liquid via branch liquid lines 48 connected to a distribution unit 49, which in turn is connected to an incoming liquid line 50 from a liquid source, not shown here, with a water pump (also not shown) .
• washing nozzles 46 can be varied freely within the scope of the following Patent Claims.
• Liquid washing is illustrated schematically with broken lines 51 from the washing nozzles 46, which can be appreciated most clearly in the enlarged view in Fig. 2. It can be appreciated in this case that the liquid washing is concentrated at the discharge end 11 of the roller grating 2, the intake end 25 of the second belt conveyor 24 and the interjacent chute 26. The coating of ash and other impurities that was deposited on the pieces of waste slag 8, 9 during the previous incineration is removed effectively during liquid washing.
• a third belt conveyor 52 is situated beneath the slag passage 27 for the onward transport of fine pieces of non-magnetic waste slag 39.
• the third belt conveyor 52 is arranged at right angles to the first belt conveyor 13.
• the third belt conveyor 52 in this way replaces the stationary slag collection point 40 in the previously described embodiment.
• feeding of the waste slag to the roller grating 2 takes place by means of an upward-angled feed belt conveyor 53.
• Angled lateral containment walls 54 enclose the feed belt conveyor 53 so that a greater volume of waste slag can be loaded onto the feed belt conveyor 53, as indicated by the arrow 55.
• the feed belt conveyor 53 like the second belt conveyor 13, is equipped with carrier projections 23 and is constructed around a beam framework 29.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Processing Of Solid Wastes (AREA)
• Combined Means For Separation Of Solids (AREA)
• Paper (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Sorting Of Articles (AREA)
• Gasification And Melting Of Waste (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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Family Cites Families (2)

• 2002
  • 2002-02-14 SE SE0200431A patent/SE0200431L/xx unknown
• 2003
  • 2003-02-13 DK DK03739663T patent/DK1474240T3/da active
  • 2003-02-13 AU AU2003210084A patent/AU2003210084A1/en not_active Abandoned
  • 2003-02-13 DE DE60328266T patent/DE60328266D1/de not_active Expired - Lifetime
  • 2003-02-13 AT AT03739663T patent/ATE435703T1/de not_active IP Right Cessation
  • 2003-02-13 WO PCT/SE2003/000234 patent/WO2003068406A1/en not_active Application Discontinuation
  • 2003-02-13 EP EP03739663A patent/EP1474240B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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