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
  • B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
  • B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
  • B07B7/083—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by rotating vanes, discs, drums, or brushes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C21/00—Disintegrating plant with or without drying of the material
• • 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
  • B07B9/00—Combinations of apparatus for screening or sifting or for separating solids from solids using gas currents; General arrangement of plant, e.g. flow sheets
  • B07B9/02—Combinations of similar or different apparatus for separating solids from solids using gas currents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C15/00—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs
  • B02C2015/002—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs combined with a classifier
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding

Definitions

• the invention relates to a sifter for sifting lumpy feed and a method for operating a classifier.
• the material In grinding systems in open mode, the material is once passed through the grinding plant and then has the desired product properties in terms of fineness and particle size distribution.
• a significant increase in the efficiency of the grinding system could be achieved through the use of classifiers, whereby the material to be ground is driven in a mill-classifier circuit.
• the fresh food can be abandoned before or after the mill.
• An oversize, as in the open mode, is reduced and the product properties can be better adjusted.
• ball mills, vertical and horizontal roller mills, stirred ball mills or high-pressure roller presses are used as mills in the cement and mineral sectors. The throughput of these mills is limited and independent of the separation result in the classifier nearly constant. In order to increase the amount of finished goods per hour, this can be done when using these mills therefore only on an improvement of the sighting.
• a better sighting has the consequence that less fines (Fertigut) is in the coarse material of the classifier and accordingly the proportion recirculated to the mill is reduced, so that a correspondingly larger proportion of fresh material in the mill can be processed.
• the classifiers have evolved from a static to a dynamic airflow sighting. That is, the rotation was added to the air flow and gravity.
• the usual structure consists in that an air guidance system is arranged around a rotating rotor cage so that a viewing zone is formed between the rotor cage and the air guidance system.
• the feed to be viewed is introduced either together with the classifying air flow through the air guidance system and / or from above directly into the viewing zone.
• the invention is based on the object of improving the visual efficiency of classifiers with a rotor basket rotating about a rotor axis and an air control system arranged around the rotor basket.
• the method according to the invention for operating a classifier for sifting lumpy feedstock has the following method steps:
• Abandonment of the chunky feed into the viewing zone wherein in the viewing zone one or more internals are arranged such that increases the torque acting on the rotor cage - at the same speed - by at least 20% compared to a version without internals and / or the distance of the air control system to the rotor cage is selected so that the torque acting on the rotor cage - at the same speed - increased by at least 20% compared to a version with a distance of the air control system without affecting the torque of the rotor cage.
• the sifter according to the invention for sifting lumpy feed has a rotor cage rotating about a rotor axis and an air guiding system arranged around the rotor cage, wherein a viewing zone is formed between the rotor cage and the air guidance system.
• a viewing zone is formed between the rotor cage and the air guidance system.
• one or more internals are arranged such that the torque acting on the rotor cage - at the same speed - increased by at least 20% compared to a design without internals and / or the distance of the air duct system to the rotor cage is selected so that on the rotor basket acting torque - at the same speed - by at least 20%> compared to a version with a distance of the air duct system without influence on the torque of the rotor cup is increased.
• an inhomogeneous flow is selectively generated in the viewing zone, at least in individual areas. It is therefore consciously away from the hitherto pursued concept of a homogeneous flow as possible and could surprisingly find in the experiments on which the invention is based, that a more effective sighting takes place precisely due to the inhomogeneous flow.
• the bypass so the proportion of the fine material, which is rejected by the classifier together with the coarse material is reduced.
• the above classifier or the associated method is also advantageous if the classifier is to produce two finished products of different grain size, since the fine material and thus the higher-quality proportion is obtained in a correspondingly larger amount.
• the increase in efficiency of the classifier is based on the fact that the installations in the viewing zone or the air guidance system placed closer to the basket cause an increased deagglomeration of the feed material to be viewed. Due to the built-in or narrowed viewing zone also flow bottlenecks, which can increase the kinetic energy of the feed particles by a multiple. As a result of the drag forces of the rotor-basket rotation and the internals, the feed material is subjected several times to a deagglomeration and again to a sighting on the rotor cage, whereby the particles can disintegrate and be more effectively sighted.
• the lumpy feed material to be inspected can be supplied together with the classifying air through the air guidance system and / or at least partially separately from the classifying air of the classifying zone.
• the rotor cage may be cylindrical, frusto-conical and / or stepped.
• the largest diameter of the rotor cage should be at least 0.5 m, preferably at least 1 m. But there are also rotor baskets with diameters of up to 8 m or more conceivable.
• the distance of the air guidance system to the rotor is preferably less than 60 mm, preferably ⁇ 55 mm, most preferably ⁇ 50 mm.
• the through the internals and / or the distance of the air control system to the rotor basket-related torque increase is preferably at least 25%, with values of at least 30% or at least 50%> higher bypass reductions are possible. In the experiments on which the invention is based, it has also been shown that torque increases of at least 75% or even at least 100% bring about an even greater increase in efficiency.
• the distance of the control system and / or the internals to the rotor cage is adjustable, so that you can park the system targeted to the available drive power of the rotor cage.
• the air duct system consists of a plurality of baffles (vanes and / or Bo genschaufeln and / or Rieselblechen), wherein the arranged in the viewing zone internals are attached to some or all of these baffles. It is also conceivable that the internals are formed by end portions of some baffles, wherein the end portions protrude into the viewing zone. The internals may extend over the entire or only part of the axial extent of the rotor cage and may be aligned parallel or not parallel to the rotor axis.
• the rotor cage has additional, projecting into the viewing zone and mitrotierende with the rotor basket components for supporting generating an inhomogeneous flow field in the viewing zone.
• the rotor basket rotates about a vertically oriented axis.
• the invention relates to a grinding plant, in particular a Umlaufmahlstrom for grinding lumpy Good with a mill and associated with the mill classifier, as described above.
• Fig. 2 is a schematic representation of a classifier with a common material and reformulationzu operation
• Fig. 3 is a schematic representation of a vertical roller mill with integrated
• FIG. 4 schematic representation of a classifier with a frusto-conical
• FIG. 5 is a sectional view of the classifier transversely to the rotor axis according to a first embodiment
• FIG. 6 is a sectional view of the classifier transversely to the rotor axis according to a second embodiment
• Fig. 7 is a detail view of the separator with a arranged in the viewing zone
• Fig. 8 is a schematic side view of the classifier with internals
• FIG. 10 shows a detail view of the separator with a component co-rotating with the rotor basket
• FIG. 11 shows a schematic representation of a rotatable installation for adjusting the distance to the rotor cage
• Fig. 12 is a schematic representation of a sliding installation for
• Adjustment of the distance to the rotor cage 13 is a diagram illustrating the torque as a function of the distance of the air duct system to the rotor cage
• Fig. 15 is a block diagram of a grinding plant consisting of mill and classifier and
• FIG. 1 shows a separator 1 with a cylindrical rotor cage 3 rotating about a rotor axis 2 and an air guiding system 4 arranged around the rotor cage, wherein a viewing zone 5 is formed between the rotor cage and the air guidance system.
• lumpy feed material 6 is placed over a arranged above the rotor basket 3 material task 7 on the ceiling of the rotor cage 3.
• Classifying air 9 is supplied to the classifying zone 5 via a classifying air feed 8 and the air guiding system 4.
• Coarse material 6a of the feed material 6 falls downwards and is discharged via a coarse material outlet 10, while the fines 6b together with the classifying air 9 is sucked into the rotor basket 3 and discharged via a fine material outlet 11.
• a sifter 1 ' according to a second embodiment is shown, which in turn has a vertical rotor axis 2' rotating rotor cage 3 'and a rotor cage surrounding air duct 4', wherein between the rotor cage and air control system a viewing zone 5 'is formed.
• the feed material 6 'to be viewed is supplied here together with the classifying air 9' via a common material and classifying air feed 12 'and enters the classifying zone 5' via the air guidance system 4 '.
• a portion of the feed material is supplied separately from the classifying air of the classifying zone 5 ', for example over the ceiling of the rotor basket 3' according to FIG. 1.
• the coarse material 6'a falling out of the classifying zone 5 ' will turn via a Grobgutauslass 10 'and with the prepare for the rotor basket fines 6'b discharged via a fine material outlet 11'.
• Fig. 3 shows a specific embodiment of a circulating system with a vertical roller mill 201, which has a grinding table 202 and thereon rolling rollers 203.
• the material to be shredded is fed via a material feed 204 above the center of the grinding plate 202.
• An inventive classifier 101 is integrated above the grinding plate 202 in the mill housing.
• the crushed by the grinding rollers 203 material passes over the edge of the grinding plate 202 to the outside and is detected there by a stream of air flowing from bottom to top and registered in the separator 101.
• the classifier is designed, for example, according to one of the exemplary embodiments illustrated in FIGS. 1 to 2.
• the coarse material of the classifier 101 is again supplied to the grinding table 202 via the coarse material outlet 110, while the classifying air is discharged together with the fine material via the fine material outlet 111.
• a separator 1 is provided with a frustoconical rotor basket 3", which in turn rotates about a vertical rotor axis 2 ".
• the air guide system 4 is designed to be complementary, so that a viewing zone 5" is again provided between the rotor cage 3 "and the air guidance system 4".
• the feed material 6 can optionally be supplied directly to the classifying air 9" and / or separately thereof to the classifying zone 5 "The coarse material is in turn discharged via a coarse material outlet 10" and the fine material via a fine material outlet 11 ".
• the air guide system 4 is formed with baffles 40 and the rotor cage 3 is equipped with rotor basket blades 30.
• the viewing zone 5 is in turn formed by the space between the air control system and rotor cage.
• the distance a of the air guide system 4 to the rotor cage 3 is chosen so that the torque acting on the rotor M - at the same speed - increased by at least 20% compared to a version with a distance of the air control system without affecting the torque of the rotor cage.
• the air guidance system 4 is formed by curved guide plates 40 '.
• the distance a of the air control system to the rotor cage is selected so that the torque acting on the rotor cage M - at the same speed - increased by at least 20% compared to a version with a distance of the air control system without affecting the torque of the rotor cage.
• an installation 13 is provided, all existing in the viewing zone 5 internals 13 are arranged such that the torque acting on the rotor cage - at the same speed - turn by at least 20% compared to a design without internals elevated.
• the internals need not necessarily have all the same distance b from the rotor cage 3.
• the at least 20% increase in the torque is due to both the internals 13 in the viewing zone 5 and by a reduced distance a of the air guide system 4 to the rotor cage 3.
• the internals 13 and / or the closer to the rotor cage 3 approached air control system 4 causes an agglomerated milieugutteilchen 60 is at least partially disagglomerated by the internals 13 and / or the air handling system 4 and thereby more efficient sighting is possible.
• the rotor basket 3 extends in the direction of the rotor axis 2 (axial extent of the rotor cage) over a height h.
• the internals 13, 17 may extend over the entire height h or a part thereof.
• the internals are arranged in parallel (installation 13) or not parallel (installation 17) in the viewing zone 5.
• Fig. 9 illustrates a variant in which the baffles 18 are formed by end portions of a baffle 42 of the air handling system.
• the installation 18 protrudes into the viewing zone 5, wherein all installations and possibly the distance of the air control system effect the at least 20% increase in the torque M of the rotor cage 3.
• the internals can in principle be designed as desired in order to exert the desired effect on the feedstock. It is particularly conceivable that various trained internals are provided in the viewing zone 5.
• components 19 which rotate with the rotor basket 3 and project the viewing zone 5 can also be provided which, in conjunction with the internals 13, lead to turbulence in turbulence (FIG. 10).
• the arranged in the viewing zone 5 baffles 20 can be arranged rotatable about a rotation axis 21, thereby to adjust the distance to the rotor cage 3 can (Fig. 11).
• the adjustment of the distance of a mounting 22 can be done according to FIG. 11 but also by shifting the installation along the double arrow 23.
• the diagram shown in FIG. 13 shows the influence of the distance a of the air guiding system 4 to the rotor 3 as a function of the torque M of the rotor cage 3 at a predetermined speed. It can be seen that the torque M decreases with increasing distance a of the air guidance system from the rotor cage and the air guidance system exerts no influence on the torque from a certain distance. In this state, the torque M in Fig. 13 is given as 100%.
• the shaded area 24 shows the known from the prior art area, according to which the distance of the control system is more than 60 mm to the rotor cage.
• the power of the torque M is to be increased by shortening the distance of the air guidance system 4 to the rotor cage 3 and / or by additional installations in the viewing zone 5 to at least 120% (area 25), preferably to at least 150%> (area 26).
• Particularly preferred is a range of more than 175% or even more than 200% of the torque over a design without internals and / or with a distance of the air control system without affecting the torque of the rotor cage.
• the bypass T m i n , norm is the minimum degree of separation of the separator curve of a classifier.
• the bypass is at a particle size smaller than that at which the separator section is located (see common practice of trump evaluation of separation curves).
• the bypass thus represents a measure of the proportion of the fine material, which is rejected by the classifier due to agglomeration with the coarse material.
• the bypass Tmi n , norm [%>] is usually normalized to compare the number of classifiers to a circulation factor (ratio of classifier input to fines) of 2, in order to eliminate influences of raw material and milling process of bypass value.
• the classifier 100 and the mill 200 is operated as Umlaufmahlstrom, wherein the coarse material 600a is returned to the mill 200 and there further comminuted together with fresh material 300.
• the fresh food can also be given to the classifier first.
• a ball mill, a vertical and horizontal roller mill, a stirred ball mill or a high-pressure roller press may be considered as the mill 200.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Combined Means For Separation Of Solids (AREA)
• Grinding-Machine Dressing And Accessory Apparatuses (AREA)
• Disintegrating Or Milling (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2013
  • 2013-02-15 DE DE102013101517.4A patent/DE102013101517A1/de not_active Ceased
• 2014
  • 2014-02-10 EP EP14703392.2A patent/EP2956249A1/de not_active Withdrawn
  • 2014-02-10 JP JP2015557389A patent/JP6581508B2/ja not_active Expired - Fee Related
  • 2014-02-10 MX MX2015010470A patent/MX2015010470A/es active IP Right Grant
  • 2014-02-10 CA CA2900880A patent/CA2900880C/en not_active Expired - Fee Related
  • 2014-02-10 BR BR112015019143-6A patent/BR112015019143B1/pt not_active IP Right Cessation
  • 2014-02-10 CN CN201480008620.8A patent/CN104994968B/zh not_active Expired - Fee Related
  • 2014-02-10 WO PCT/EP2014/052543 patent/WO2014124899A1/de active Application Filing
  • 2014-02-10 US US14/768,045 patent/US10137478B2/en not_active Expired - Fee Related

Non-Patent Citations (2)

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