Classifications

• • 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
  • B07B4/00—Separating solids from solids by subjecting their mixture to gas currents
  • B07B4/02—Separating solids from solids by subjecting their mixture to gas currents while the mixtures fall

Definitions

• the invention relates to cone sifters for sifting restricted or non-free-flowing bulk material, which has a light material fraction and a heavy material fraction, and methods for carrying out the sifting.
• U is a cone sifter with a housing, with a filler tube protruding from above into the upper housing section for introducing the bulk material, with a double cone arranged below the outlet opening of the filler pipe, with a main air inlet connected to the lower housing section and with a air outlet connected to the upper housing section, a flow channel being formed between the filler pipe and the double cone on the one hand and the housing on the other hand.
• the bulk material or the product mixture is fed from the center through the filler pipe onto the inner double cone.
• the bulk material is distributed evenly over the entire classifier cross-section and thus reaches the main viewing zone, which is formed between the double cone and the housing.
• the air flow supplied from below occurs within the flow channel onto the debris falling into the flow channel from the lower edge of the distributor cone, which forms the upper cone of the double cone.
• the main air flow in the flow channel thus runs transversely to the direction of movement of the bulk material, so that the screening process ren is a cross-flow sighting.
• the main viewing zone In the main viewing zone, a large part of the light goods are pulled out of the heavy goods, the main viewing zone being constructed in such a way that the ascending light goods and the falling heavy goods do not interfere with each other.
• the light material is reliably separated and removed from the cone classifier via the air outlet arranged on the upper housing section, the classifier head.
• the heavy goods are discharged via an outlet arranged on the lower housing section, the classifier foot.
• an after-viewing zone for heavy goods is provided in the area of the main air intake.
• cross-flow screening occurs, as a result of which light goods which have not been separated from the heavy goods in the main screening are separated and transported in the direction of the main viewing zone and furthermore in the direction of the air outlet. Due to the current conditions, this is in the aftermath zone of the Heavy goods separated light goods are transported against the surface of the lower cone of the double cone.
• the cone classifiers known from the prior art described above have been used successfully with free-flowing bulk material. If, on the other hand, the bulk material is only of limited or not flowable at all, blockages occur in particular at the outlet opening of the filler pipe directly above the double cone and in the region of the surface of the lower cone of the double cone.
• the restricted or non-free-flowing bulk material mainly consists of structures that have a large surface area with a low weight. This is particularly the case with paper and cardboard, where individual sheets have a small volume with a very large surface area. This means that they tend to clump together due to interlocking and interlocking and to attach to surfaces due to friction and adhesive forces.
• the bulk material is braked sharply at the points described above, so that larger amounts of bulk material accumulate, as a result of which the described blockages occur which can put the cone classifier out of operation.
• the invention is therefore based on the technical problem of designing and developing the cone sifter known from the prior art and the associated screening method in such a way that blockages within the bulk material flow are largely avoided.
• a cone sifter according to claim 1 in that at least one filler air inlet is connected to the filler tube for admitting a downward air flow within at least part of the filler tube.
• the air flowing from top to bottom conveys the bulk material in the direction of the double cone, since in addition to the weight of the particles of the bulk material, the downward air flow acts as an additional force component in the direction of gravity. This enables the bulk material to be safely introduced into the classifier without any blockages forming. This is also with one - 5 -
• the at least one filler air inlet is preferably arranged at the upper end of the filler pipe and connected to the filler pipe via a distributor ring and an annular gap formed between a filler neck and the filler pipe.
• the bulk material is thus subjected to the downward air flow through the filler pipe along the entire drop distance. Blockages along the entire pipe are thus prevented in the beginning.
• a plurality of filling air inlets arranged in the wall of the filler tube and admitting a downward air flow within the filler tube can be provided, which are in particular designed as nozzles.
• nozzles are in particular designed as nozzles.
• a connecting line connects the fill air inlet to the air supply to the main air inlet.
• a secondary air flow is admitted through the filler pipe without additional expenditure on air flow generators.
• the line for the filling air inlet is preferably with the high pressure side of the circulating air system connected near the fan.
• the connecting line has a throttle valve in order to be able to adjust the amount of air through the filler pipe.
• the air flows can also be generated in an open system, the air outlet not being connected to the main air inlet.
• the filler air inlet can be connected to an additional compressed air generator in order to generate a high-strength airflow in the filler pipe.
• This embodiment can be used in particular when using nozzles as filling air inlets.
• the cross section of the flow channel between the filler pipe and the upper housing section at least in sections larger than the cross section of the flow channel between the double cone and the middle housing section. Due to the larger amount of air flowing through and the larger cross section, approximately the same flow velocities can be achieved in the sections of the flow channel which are passed through in succession. Changes in the flow cross-sections can be used specifically to adjust the air speeds in the different viewing zones.
• the distance between the outlet opening of the filler pipe and the tip of the double cone is preferably adjustable.
• the size of the outlet gap between the two can thus be changed and adapted to the quantity of bulk material introduced. Occur frequently beginning Blockages, which are each resolved by the downward flow of secondary air within the filler pipe, the gap between the outlet opening of the filler pipe and the distributor cone can be increased to give more space for the bulk material to pass through.
• the problem of the asymmetrical introduction of the bulk material can be eliminated by at least one guide element in the filler pipe, with which the bulk material is centered relative to the tip of the double cone. Even if the at least one guide element constricts the cross section within the filler pipe, the beginning blockages occurring in the passage opening of the guide element are eliminated by the downward directed air flow.
• the above-mentioned technical problem according to claim 9 is solved by a cone separator in that at least one displacer cone air inlet is connected to the interior of the displacer cone and that an annular gap is provided between the cylindrical connector and the double cone.
• a cone separator in that at least one displacer cone air inlet is connected to the interior of the displacer cone and that an annular gap is provided between the cylindrical connector and the double cone.
• the width of the annular gap is preferably adjustable so that the intensity of the upward air jet can be regulated.
• the at least one displacer cone air inlet is designed as a support strut for the displacer cone.
• An additional function is thus assigned to the support strut, which is known per se. There is therefore no need for any additional elements which have to be arranged within the material flow.
• an outlet opening is preferably provided at the lower end of the displacement cone, through which the air introduced into the displacement cone can also exit.
• the lower outlet opening is necessary not least because particles entering through the annular gap would accumulate inside the displacement cone without the outlet opening and would ultimately lead to a blockage of the displacement cone.
• a regulating body allows the outlet opening to be adjusted in size, which creates a further degree of freedom of regulation.
• the regulating body also serves to laterally deflect the air flow emerging from the displacement cone and to supply it to the main air flow.
• a support strut for a cone classifier of the type described above for carrying the double cone within the housing in that the support strut is designed as an air-supplying hollow tube and that a plurality of openings in the wall of the hollow tube are arranged.
• the air flow emerging through the openings prevents heavy or light goods particles from accumulating on the surface of the support strut. If the particles come to rest on the surface of the support strut, the particles are detached by the air flow emerging from the openings, so that they continue to slide downward by gravity. This effectively prevents partial clogging of the flow channel in the area of the support struts.
• the openings are preferably arranged essentially on the upper sides of the hollow tube, since The particles falling from above accumulate on these surfaces.
• a preferred embodiment also consists in that the air flow emerging from the openings is distributed through a fabric layer arranged on the circumferential side of the hollow tube. The number of openings can thus be reduced, since the fabric layer ensures that the outward air flow is distributed uniformly, so that no deposit of particles of the bulk material flow can occur on any partial surface of the holding strut.
• the cone sifters explained above and the sifting methods have a positive effect, in particular in the case of bulk material which is restricted or cannot be poured.
• the free-flowing properties of a bulk material can be characterized in that the bulk material consisting of individual particles ensures continuous free flow essentially without clumping or caking. Granules are therefore pourable. The pourability is limited, among other things, when the particles of the bulk material have a low weight with a large surface area. This results in entanglement and interlocking between the particles of the bulk material due to the fact that they lie flat against one another, as well as high frictional and adhesive forces, which make it difficult or impossible to move the individual particles independently of one another.
• Restricted or non-free-flowing bulk material is, for example, a mixture of paper and cardboard, the bulk material being crushed before being sifted.
• a bulk material prepared in this way from a mixture of comminuted nertem paper and cardboard can then be spotted using the cone sifter according to the invention, so that the paper is separated as light goods from the cardboard as heavy goods.
• Waste paper that has been collected in conventional collection containers consists of 70% to 80% paper and approx. 20% to 30% cardboard, with a small proportion of contaminants such as metals, minerals, plastics and the like still contained in the mixture.
• the properties of the shredded waste paper can be characterized as follows.
• the mixture consists of very light and large-sized particles and therefore tends to form bridges and thus to accumulate in narrow places in the material flow as well as on surfaces and form blockages.
• the measures according to the invention prevent these blockages, so that the screening process for separating paper and cardboard can also be used in the case of restricted or not free-flowing bulk material.
• restricted or non-free-flowing bulk goods are a mixture of composted material and foils or the like, shredded plastic packaging material or a light shredder fraction.
• FIG. 1 shows a first exemplary embodiment of a cone classifier according to the invention in cross section, the material flow in the form of particles and the air flows being drawn in as arrows,
• Fig. 2 shows the cone sifter shown in Fig. 1
• Fig. 6 shows a second embodiment of a cone sifter according to the invention in cross section, the air flows are shown with arrows, and
• FIGS. 1 and 2 show the side view of the conical sifter according to the invention shown in FIGS. 1 and 2 together with a circulating air system.
• FIGS. 3 to 5 show a first exemplary embodiment of a conical classifier according to the invention, FIGS. 3 to 5 representing corresponding cross sections.
• the conical sifter generally identified by 100, has a housing 2 with an upper housing section 2a, one middle housing section 2b and a lower housing section 2c.
• a filler tube 4 protrudes from above into the upper housing section 2a and is used to introduce the bulk material.
• a main air inlet 12 is connected to the lower housing section 2c, while an air outlet 14 is connected to the upper housing section 2a.
• the air flowing in through the main air inlet 12 is supplied via a distributor ring 13 to the lower housing section 2c in a radially distributed manner, the distributor ring 13 being circular, as shown in FIGS. 3, 4 and 5.
• a flow channel 16 is formed between the filler pipe 4 and the double cone 6 on the one hand and the housing 2 on the other hand.
• This cone sifter results in particular from FIG. 1.
• the bulk material which has a light material fraction and a heavy material fraction, is introduced into the filler tube 4 from above using a cellular wheel sluice 18.
• a filler neck 20 is provided at the lower end of the cellular wheel sluice.
• the particles of the light goods are represented as lines and the particles of the heavy goods as circles in order to distinguish them graphically from one another.
• the bulk material After passing through the filler pipe 4, the bulk material reaches the distributor cone 8 and slides downward and radially outward on its conical surface.
• the bulk material slides off at the lower outer edge of the distributor cone 8, that is to say at the contact edge with the lower cone 10, and falls into the flow channel 16
• Air flow shown by arrows which enters the housing 2 via the main air inlet 12 and is initially directed downwards at a conical guide surface 22, flows into the flow channel 16 from below.
• the air flow hits the bulk material, the particles of the light material being lifted upward due to the air speed, while the particles of the heavy material essentially fall downward.
• the spatial region of the flow channel 16 in the vicinity of the lower end of the distributor cone 8 thus represents the main viewing zone 24. Due to the direction of movement of the bulk material and the direction of flow of the air flow in the flow channel 16, a cross-section of the bulk material takes place in the main viewing zone 24.
• the separated light material rises with the one in the flow channel 16, which is formed between the inlet pipe 4 and the upper housing section 2a.
• the flow velocity of the air flow is set so that heavy goods particles detach from the separated fraction and fall down.
• this after-inspection of the light goods also known as countercurrent screening, there is a further improvement in the purity of the light goods fraction.
• the heavy material falling down from the main viewing zone 24 collides against the inner wall of the central housing section 2b and then slides down along the guide surface 22.
• the lower end of the guide surface 22 represents the discharge edge 26, from which the particles of the separated heavy material fraction once again enter the air stream that flows around the discharge edge 26 from the main air inlet runs around into the flow channel 16 upwards.
• an inspection of the heavy material fraction takes place in the area of the flow channel 16 near the discharge edge 26, which in turn represents a transverse view.
• Light goods particles, which are still in the heavy goods fraction after the main screening are detached from the air flow in the screening and are directed towards the surface of the lower cone 10 in order to be transported from there upwards in the direction of the main viewing zone 24.
• the heavy material gets into the tapered lower housing section 2c and is discharged with the help of a rotary valve 19 for further processing.
• blockages occur at the outlet opening 4a of the filler pipe 4 near the distributor cone 8 and along the surface of the lower cone 10, since the material of the bulk material is only free-flowing to a limited extent.
• a filling air inlet 28 is connected to the filling pipe 4, whereby a downward air flow can be let inside the filling pipe 4.
• the filler inlet 28 is connected to the upper end of the filler pipe 4.
• the filler air inlet 28 is connected to the filler pipe 4 via a distributor ring 29 and an annular gap 31 formed between a filler neck 20 and the filler pipe 4.
• the air flow supplied is thus directed downward from the annular gap 31 into the interior of the filler pipe 4.
• a connecting line 30 is provided, which connects the filling air inlet 28 mt of the air supply to the main air inlet 12.
• a throttle valve 32 is arranged in the connecting line 30 to regulate the strength of the air flow through the filling air inlet 28.
• the flow cross section of the upper section of the flow channel 16 formed between the filler pipe 4 and the upper housing section 2a is larger in sections than the flow cross section of the lower section of the flow channel 16 formed between the double cone 6 and the middle housing section 2b.
• the upper housing section 2a has two conical sections trained housing sections 34 and 36. In the area of the housing sections 34 and 36, due to the widening flow cross section, the flow rate of the rising air is lower, so that the light material fraction can be inspected in this area.
• the flow cross-section which is again reduced above the housing section 34, then serves the purpose To accelerate air for a deflection into the air outlet 14.
• the filler pipe 4 has at its lower end a displaceable pipe section 4b with which the vertical position of the outlet opening 4a can be adjusted.
• a displaceable pipe section 4b with which the vertical position of the outlet opening 4a can be adjusted.
• a guide element 38 is also arranged within the filler pipe 4 in order to center the bulk material relative to the tip 6a of the double cone 6. This is necessary because the cellular wheel sluice 18 provided for introducing the bulk material into the filler pipe 4 does not ensure a symmetrical introduction of the bulk material. On the contrary, the movement of the rotary valve 18 often leads to the bulk material being applied on one side to the tip 6a of the double cone 6. The guide element 38 counteracts this, since the bulk material is centered at a short distance above the double cone 6 on its tip 6a.
• a displacement cone 40 with an upper cone 40a and a lower cone 40b is arranged below the double cone 6. Furthermore, a cylindrical connecting piece 42 is provided which connects the upper cone 40a to the lower cone 10.
• the displacement cone 40 serves mainly to guide the air stream entering via the main air inlet 12 and guided by the guide surface 22 upward into the flow channel 16. Without the displacement cone, the air flow portions entering radially from all sides from the distributor ring 13 would meet and swirl below the double cone 6, so that no uniform flow along the flow channel 16 could be achieved.
• the interior 44 of the displacer cone 40 is connected to a displacer cone air inlet 46, through which a secondary air stream branched off from the main air stream is supplied.
• the supplied secondary air flow leaves the interior 44 of the displacement cone 40 through an annular gap 48 formed between the cylindrical connecting piece 42 and the lower cone 10 of the double cone 6, so that an upward air flow forms along the surface of the lower cone 10. This is shown in Fig. 1 with small arrows.
• the additional upward air flow reliably prevents light goods particles, which have been released in the indulgence of the heavy goods, from accumulating on the surface of the lower cone 10 and from forming blockages.
• the double cone 6 is connected to the cylindrical connection piece 42 of the displacer cone 40 via a holder 50.
• the double cone 6 is attached to itself within the housing 2, so that no additional support struts for the double cone 6 are required.
• the bracket 50 is designed so that the distance between the double cone 6 and the cylindrical nozzle 42 can be changed with the aid of a screw connection. The size of the annular gap 48 can thus be changed for setting the air quantity.
• the displacer cone air inlet 46 is designed as a support strut for the displacer cone 40, as a result of which the cylindrical connecting piece 42 and the double cone 6 are also carried. It is therefore not necessary to provide an additional supply line for supplying an air flow in addition to the support struts which are present per se. As shown in FIG. 5, all four support struts are designed as displacement cone air inlets 46. However, since the displacer cone air inlet 46 has a larger diameter than a normal mounting strut, it is also possible to design only one or at least not all of the mounting struts as displacer cone air inlets 46. The aim here is not to restrict the cross section of the flow channel 16 in the region of the mounting struts more than is necessary.
• FIG. 1 and 2 also show that at the lower end of the displacement cone 40, that is to say at the lower tip of the lower cone 40b, there is an outlet opening 52 in which a regulating body 54 is arranged.
• the regulating body 54 is held by means of a holder 56 arranged in the interior 44 in the region of the lower cone 40b, the distance between the regulating body 54 and the outlet opening 52 being adjustable by means of a screw connection.
• the amount of air exiting through the outlet opening 52 can thus be tiv to be adjusted to the amount of air emerging through the annular gap 48.
• the regulating body 54 also has a conical surface in order to laterally deflect the emerging air flow.
• the mobility of the regulating body 54 in the vertical direction is shown in FIG. 1 with a small double arrow.
• the support strut 46 is designed as an air-supplying hollow tube and has a plurality of openings 58 in the wall. An air flow emerges through these openings, so that particles which accumulate on the surface of the holding strut 46 are detached from the air flow emerging from the openings 58. This effectively prevents deposits that are too large from forming on the support struts 46. Since the particles of the air flow essentially fall onto the support struts 46 from above, the openings 58 are preferably formed on the upper side of the support struts 46.
• FIG. 6 shows a second exemplary embodiment of a conical sifter 100 ′ according to the invention, which essentially corresponds to the previously described exemplary embodiment. Therefore, the same reference numerals designate the same device elements as previously described with reference to FIGS. 1 to 5.
• a further double cone 60 is provided, which has an upper cone 60a and a lower cone 60b.
• a cylindrical nozzle 62 connects the upper cone 60a to the lower cone 10.
• the interior 64 of the double cone 60 is fluidically connected to the interior 44 of the displacement cone 40 and of the cylindrical connecting piece 42. Furthermore, an annular gap 66 is formed between the cylindrical connecting piece 62 and the lower cone 10, through which an air flow is admitted along the surface of the lower cone 10. Similarly, with the aid of the annular gap 48 formed between the lower cone 60b and the cylindrical neck 42, an air flow is formed along the surface of the lower cone 60b. In this way, it is effectively prevented at both lower cones 10 and 60 b that light goods particles can accumulate on the surface and lead to blockages.
• the double cone 60 is held vertically adjustable relative to the displacement cone 40.
• Another bracket 68 is connected to the cylindrical nozzle 62 and carries the double cone 6, so that it is vertically adjustable relative to the double cone 60.
• FIG. 7 finally shows the cone sifter according to the invention together with a device for generating a circulating, closed air flow.
• the circulating air cycle is described starting with a fan 70.
• the fan 70 draws in air via an intake line 72 and delivers it at the outlet with increased pressure to the main air inlet 12 of the classifying cone 100 via the supply line 74.
• Two secondary lines 76 and 78 are branched off along the supply line 74, which serve to supply the filling air inlet 28 via the connecting line 30 on the one hand and to supply the displacer cone air inlets 46.
• Two throttle valves 80 and 82 are arranged in the supply line 74, on the one hand to be able to adjust the total amount of air and on the other hand the ratio of the main air flow to the main air inlet 12 and the secondary air flows through the secondary lines 76 and 78. Furthermore, the above-mentioned throttle valve 32 in line 30 serves to adjust the ratio of the air quantities in the secondary lines 76 and 78.
• the separated light material with the exhaust air enters an exhaust air line 84 which is connected to the inlet 86 of a cyclone.
• the exhaust air is let in tangentially within the cylindrical section 90 of the cyclone 88, so that a rotational flow is generated within the cyclone 88. This creates centrifugal forces that throw the light goods out of the air stream.
• the light material then moves downward spirally along the container wall into the calming funnel 92 due to the air flow. From there, the light material passes outside via a cellular wheel sluice 94 and can be processed further.
• the air flow separated from the light material arrives inside the cyclone 88 in a dip tube, not shown, which is connected to an outlet 96, which in turn is connected to the suction line 72 of the fan 70. This results in a closed air recirculation mode.
• the mixed material and the heavy and light material fractions can be introduced and exported from outside via the cellular wheel locks 18, 19 and 94.

Landscapes

• Combined Means For Separation Of Solids (AREA)
• Centrifugal Separators (AREA)
• Supply Of Fluid Materials To The Packaging Location (AREA)
• Analysing Materials By The Use Of Radiation (AREA)
• Feeding Of Articles To Conveyors (AREA)

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• 1999
  • 1999-12-02 DE DE19957993A patent/DE19957993B4/de not_active Expired - Fee Related
• 2000
  • 2000-11-18 EP EP00993231A patent/EP1156892B1/fr not_active Expired - Lifetime
  • 2000-11-18 DK DK00993231T patent/DK1156892T3/da active
  • 2000-11-18 JP JP2001541624A patent/JP2003515447A/ja active Pending
  • 2000-11-18 AT AT00993231T patent/ATE261783T1/de not_active IP Right Cessation
  • 2000-11-18 ES ES00993231T patent/ES2221871T3/es not_active Expired - Lifetime
  • 2000-11-18 WO PCT/EP2000/011496 patent/WO2001039899A1/fr active IP Right Grant
  • 2000-11-18 DE DE50005686T patent/DE50005686D1/de not_active Expired - Fee Related
  • 2000-11-18 AU AU54374/01A patent/AU5437401A/en not_active Abandoned
  • 2000-12-01 TW TW089125625A patent/TW473402B/zh active

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