[go: up one dir, main page]

WO1986005420A1 - Appareil de triage de materiaux secs - Google Patents

Appareil de triage de materiaux secs Download PDF

Info

Publication number
WO1986005420A1
WO1986005420A1 PCT/US1985/000478 US8500478W WO8605420A1 WO 1986005420 A1 WO1986005420 A1 WO 1986005420A1 US 8500478 W US8500478 W US 8500478W WO 8605420 A1 WO8605420 A1 WO 8605420A1
Authority
WO
WIPO (PCT)
Prior art keywords
wind tunnel
screen
particles
granular material
sorting device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1985/000478
Other languages
English (en)
Inventor
James D. Vickery
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to PCT/US1985/000478 priority Critical patent/WO1986005420A1/fr
Publication of WO1986005420A1 publication Critical patent/WO1986005420A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
    • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
    • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
    • B07B1/4672—Woven meshes
    • 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
    • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
    • 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
    • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
    • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
    • B07B1/469—Perforated sheet-like 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
    • 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
    • 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
    • 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
    • B07B2201/00—Details applicable to machines for screening using sieves or gratings
    • B07B2201/04—Multiple deck screening devices comprising one or more superimposed screens

Definitions

  • the present invention relates generally to material separation devices and more particularly to a pneumatic device for physically sorting mixtures of granular materials having component materials, such as sand and gold with different specific gravities.
  • a particle of mass, m, free falling through a horizontal air stream of velocity, V, is accelerated vertically by the force of gravity, G.
  • the particle is accelerated horizontally by the flow of air against and around it having a force usually referred to as "drag", D.
  • the drag force is in turn dependent upon the relative velocity of the wind with respect to the particle. As the particle is accelerated in the horizontal direction, the relative velocity of the particle with respect to the wind diminishes until at some point the particle is moving horizontally at the same velocity as the wind. At this point the drag force on the particle is zero.
  • the viscosity of air,- ⁇ under operating conditions of the invention remains constant; thus, it may be seen that the drag force D which accelerates a particle horizontally varies linearly with both the diameter of the particle and with the relative air speed of the particle.
  • the initial drag force experienced by spherical particles introduced into a moving air stream will vary linearly with the diameter of the particle.
  • the horizontal acceleration, a, of a particle of mass, m is therefor: _ F _ D d ( v ⁇ V) M M
  • the particle having the smaller mass i.e. smaller specific gravity
  • a particle of sand, specific gravity of 2.3 will be accelerated more than a particle of gold, specific gravity 19.3, of the same diameter. This effect will be referred to generally as the "specific gravity effect”.
  • the mass of an object is directly proportional to the product of its volume and specific gravity and may be expressed as m - K, (Vol.) (Sp. Gr.) where K., is a
  • the "specific gravity effect” which causes lighter particles to be initially accelerated more than heavier particles of the same size will cause the heavier particles to fall out of the airstream at a point nearer the drop point then the lighter particles.
  • the "sizing effect” which causes small particles to be accelerated faster than large particles of the same material will cause the large particles to fall at a point nearer the drop point than the small particles.
  • a moving air stream may be used as a sorting device with denser particles such as gold falling in an area near the drop point and lighter particles such as sand falling at a greater distance.
  • gold and sand particles of random sizes are mixed together, the sorting function of the air
  • the present invention utilizes a horizontal air flow to sort particles of different materials which are combined in a granular mixture.
  • Different screening techniques are used in the invention in order to offset the "sizing effect" and effectively sort the granular
  • One technique employed by the invention is prescreening of material that is to be injected into a horizontal wind tunnel. When particles dropped are of substantially the same diameter the sizing effect is diminished and the particles tend to be sorted on the
  • Another method for overcoming the sizing effect is to use a screen having graduated apertures, referred to hereinafter as a "dynamic screen", to separate particles as they fall out of the wind tunnel.
  • a screen having graduated apertures referred to hereinafter as a "dynamic screen”
  • variously sized particles of the heavier element are dropped into the wind tunnel alone. The distances at which the particles land and the diameters of the particles are recorded.
  • a screen mesh or apertured plate is then constructed having apertures at the experimentally determined points of sufficient size to allow the heavy material particles landing at those points to pass through the apertures at relatively small tolerances. It will be found that this produces a plate having large apertures near the material drop point and progressively smaller apertures proceeding in a downstream direction.
  • the particles landing on the dynamic screen are of relatively larger sizes than the heavier metal particles landing in the same place.
  • the heavier metal particles will pass through the screen and may be collected thereunder while the lighter material particles are retained on the surface of the screen. If the screen is inclined slightly to one side and vibrated the lighter material may be allowed to roll off the side and collected for removal.
  • the mathematically predicted results are based on an assumption that the particles are relatively spherical and that the operation takes place at a relatively low Reynolds Number. If excessive air velocities are used or if a particle's shape varies substantially from a spherical shape, other aerodynamic effects are introduced which reduces the effectiveness of the invention. However, it must also be noted that if air velocities are too low, there may not be sufficient drag force to generate a noticeable separation in the larger particles. Thus determination of air velocity by experimental testing is desirable.
  • Figure 1 is an elevation view of a dry material sorting device
  • Figure 2 is a cross sectional elevation view of a dry material sorting device
  • Figure 3 is a cut away elevation view of a dry material sorting device
  • Figure 4 is a perspective view of a screen apparatus
  • Figure 5 is a perspective view of a truck bed mounted dry material sorting device with multiple wind tunnel chambers and attached screen apparatus;
  • Figure 6 is an elevation view of another embodiment of a dry material sorting device
  • Figure 7 is a plan view of a dynamic screen
  • Figure 8 is a plan view of another embodiment of a dynamic screen.
  • the dry material sorting device 10 of the present invention comprises a wind tunnel in fluid communication with air forcing means such as a blower 14.
  • a container for holding granular material such as hopper 18 is mounted on an upper portion of the wind tunnel 12 at the upstream end.
  • wind tunnel chamber 33 has a generally rectangular cross sectional shape defined by two vertical walls 32 and a top horizontal wall 34 in sealed attachment therewith.
  • the wind tunnel walls 32, 34 are formed from a smooth planar material such as sheet metal or the like.
  • the chamber 33 is open at the bottom end and at either end of the tunnel and the height and cross sectional shape are uniform throughout the length to provide an airflow of relatively constant velocity.
  • Wind tunnel 12 is supported by a frame 22 having spaced vertically upright posts 24 welded or otherwise rigidly attached to longitudinal members 26 and transverse cross members 28.
  • the wind tunnel is supported on the frame 22 as by longitudinal members 26 fixedly attached to either side of wind tunnel walls 32 and/or by connector bolts 35 attached to a lower portion of the walls 32 and connected to connector bar 27.
  • a generally V-shaped skirt 36 comprising skirt walls 38 rigidly attached to the lower portion of wind tunnel walls 32 communicates with the lower portion of the chamber 33 and is used to direct falling particles inwardly at the terminal portion of free fall.
  • opposite longitudinal ends of the skirt 36 are enclosed as by skirt plates 40 to prevent horizontal airflow through the skirt.
  • a blower 42 may be mounted on a suitable stand such as pedestal 46 mounted with wheels 48 to facilitate movement and adjustment during assembly of the device 10.
  • the blower may comprise an induction fan 42 provided with velocity controls 44.
  • the fan 14 discharges into a sealingly connected blower duct 49 of truncated pyramid config ⁇ uration having a frame formed from inclined longitudinal members 50 and transverse members 52. Side walls 54 of the duct 49 are sealingly attached to the frame members 50, 52 and may be constructed from trapezoidal sheet metal plates or the like.
  • a transverse plate 64 having a plurality of uniformly spaced holes therein may be positioned at the end of the blower duct 16 to equalize pressure distribution within the duct chamber 51.
  • Air veins 56, 60 mounted on air veins shafts 57, 61 may be pivotly mounted on blower duct transverse members 52 and provided with control knobs 62, 58 to adjust and control the direction of air flow through the duct chamber 51.
  • An injection duct 63 comprising injection chamber 66 having an identical cross section to the wind tunnel chamber 33 communicates with connects duct 16 outlet and wind tunnel 12 inlet.
  • the injection chamber 66 is defined by enclosing wall members 67 mounted on longitudinal frame members 68 in turn weldingly or otherwise rigidly attached to wind tunnel and air duct frame members 24,52.
  • a transparent elongate plate 67 may be mounted on a cutout portion of an injection chamber side wall 67 and provided with transverse ports 72.
  • Streamers or the like may be inserted through the ports for observing the relative air flow velocities at any point within the injection chamber.
  • the air flow may be adjusted by means of veins 60, 56 to achieve a uniform flow distribution through the injection chamber 66 and wind tunnel chamber 33.
  • Venturi tubes or other devices may be inserted in ports 72 to measure air flow velocities. Screw-plugs or other conventional sealing means are provided to close the ports 72 after the measurements have been made.
  • a hopper 18 having a conically shaped container 74 may be mounted on a mounting plate 75 with a hole 73 therein immediately above the injection chamber 66.
  • the hopper 18 may be provided with baffle plates 76 or a vibrator (not shown) to facilitate movement of granular material 15 therethrough.
  • a transverse slit 77 running the width of the injection chamber 66 may be formed from a fixed plate 68 and movable plate 80 operably mounted on the container wall 74.
  • a slit control knob 82 may be provided to allow an operator to change the width of the slit 77. This control 82 facilitates injection of the proper amount of granular material 15 into the air chamber. If the slit is too large the material will tend to "bunch up" or "piggyback" which diminishes the effectiveness of the device 10 in that all of the particles 15 are not equally exposed to the horizontal air flow.
  • a slit closure plate 84 with control knob 86 may be pivotally mounted below the slit to stop or start the flow of material.
  • granular material 15 is screened before it is injected into the injection chamber 66.
  • One screening arrangement as shown by Figure 4 comprises a series of screen means such as a wire screen mesh 130 mounted on a rectangular wood frame 128 in turn pivotally mounted in vertical alignment between two vertical post members 124 mounted on a rectangular base 126.
  • Each screen 131-139 is of progressively smaller mesh from top to bottom.
  • Granular material poured onto the top screen will therefore descend through the screens with each screen retaining those particles having a diameter larger than the retaining screen and smaller than the screen mounted immediately above it.
  • first screen 131 may be provided with #2 mesh having a clear opening of .965 centimeters (.380 inches); second screen 132 with #4 mesh, opening .452 centimeters (.178 inches); third screen 133 with #8 mesh, opening .229 centimeters (.090 inches); fourth screen 134 with #16 mesh, opening .113 centimeters (.0445 inches); fifth screen 135 with #30 mesh, opening .0566 centimeters (.0223 inches); sixth screen 136 with #50 mesh, opening .0279 centimeters (.011 inches); seventh screen 137 with #100 mesh, opening .0127 centimeters (.0055 inches); eighth screen 138 with #200 mesh, opening .00737 centimeters (.0029 inches); ninth screen 139 with #400 mesh, opening .00381 centimeters (.0015 inches).
  • the screens may be alternately tilted in opposite directions and provided with collection troughs (not shown) to collect the materials retained on each tray.
  • a batch of material retained on any given screen 131-139 is placed in the hopper 18, one batch at a time, for sorting.
  • Other screening means and conveying means for placing individual batches in a wind tunnel 12 may also be practiced.
  • a cascading series of mesh covered drums 122 mounted on a suitable frame 124 may be provided with inclined collection trays 126 mounted immediately below each drum 122 and discharging into the interior of each succeeding drum 12.
  • End chutes 128 may be provided to collect material retained on the interior of each drum and rolling out the lower end thereof through the action of gravity.
  • the chutes 128 may be adapted to feed into a multiple air chamber arrangement 152 to facilitate continuous blowing of materials rather than blowing of individual batches in a single chamber 33.
  • a single blower 14 with multiple ported air ducts 16 may be equipped with control valves (not shown) and a control panel 154 to match the air flow velocity with the particular particle size in a given air chamber 152.
  • Multiple blowers could also be used.
  • Such a unit might be mounted on a truck bed 150 to facilitate transportation from site to site.
  • the slit width is adjusted to the proper dimension for the material.
  • the fan 42 is then turned on and adjusted to a velocity compatible with the material 15 in the hopper 18. Suitable adjustments are made through the use of vein control knobs 58, 62 to provide a uniform air flow through the wind tunnel 12.
  • the slit closure plate 84 is then lowered allowing a narrow band of particles 15 to fall into the injection chamber 66. As the granular material particles 15 fall into the injection chamber 66 horizontal air flow through the chamber accelerates the particles in a downstream direction.
  • a dynamic screen 90 may be used to obviate prescreening.
  • the dynamic screen may comprise a v/ire mesh having progressively smaller apertures therein or as shown by Figure 8 may comprise a plate bored with holes of progressively smaller size proceeding in a downstream direction.
  • the dynamic screen will have to be constructed on the basis of the "fallout" characteristics of the particle having the higher specific gravity and will also depend on the air velocity in the wind tunnel 12.
  • the collection tray 20 is mounted below the dynamic screen 90 and a side trough 92 is mounted at the edge of the dynamic screen. As described above as particles fall through the wind tunnel those having a higher specific gravity tend to fall out nearer the drop point than those with a lower specific gravity of the same diameter.
  • the tray 90 may be tilted in the direction of the trough 92 and may also be vibrated as by a vibrator 94 to cause the retained material to roll off the screen into the trough 92.
  • a vibrator 94 to cause the retained material to roll off the screen into the trough 92.

Landscapes

  • Combined Means For Separation Of Solids (AREA)

Abstract

Appareil de triage de matériaux secs servant à trier de manière sélective des mélanges de matériaux granulaires comprenant des composants tels que du sable et de l'or possédant des poids spécifiques différents. Dans un premier mode de réalisation, un dispositif de pré-criblage (120) est utilisé pour séparer les particules par lots en fonction de leur taille. Chaque lot est ensuite envoyé à une soufflerie horizontale (12) où les particules plus lourdes tombent, lorsqu'elles sont entraînées par le jet d'air, plus près du point d'introduction que les particules plus légères, la séparation s'effectuant en fonction des poids spécifiques. Dans une variante, le criblage est effectué en utilisant un tamis dynamique (90) possédant des ouvertures de taille variable, après la séparation des particules dans la soufflerie (12) en fonction de leur poids spécifique.
PCT/US1985/000478 1985-03-19 1985-03-19 Appareil de triage de materiaux secs Ceased WO1986005420A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US1985/000478 WO1986005420A1 (fr) 1985-03-19 1985-03-19 Appareil de triage de materiaux secs

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1985/000478 WO1986005420A1 (fr) 1985-03-19 1985-03-19 Appareil de triage de materiaux secs

Publications (1)

Publication Number Publication Date
WO1986005420A1 true WO1986005420A1 (fr) 1986-09-25

Family

ID=22188619

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1985/000478 Ceased WO1986005420A1 (fr) 1985-03-19 1985-03-19 Appareil de triage de materiaux secs

Country Status (1)

Country Link
WO (1) WO1986005420A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5400908A (en) * 1993-07-26 1995-03-28 Prestwood; James R. Method and apparatus for separating materials of different weights
CN113499989A (zh) * 2021-07-23 2021-10-15 西安赛隆金属材料有限责任公司 一种用于球形空心粉末的分选装置及方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10272A (en) * 1853-11-29 gritzner
FR336106A (fr) * 1903-10-17 1904-02-29 Leon Bloume Système de classement de toutes matières par volume et densité
US846140A (en) * 1906-10-22 1907-03-05 Louis F Lumaghi Coal screening and grading apparatus.
US916625A (en) * 1907-12-04 1909-03-30 Robert Stein Separator.
GB284546A (en) * 1927-07-11 1928-02-02 Gerald Petrie Improvements relating to apparatus for sorting and grading refuse and other mixed materials
US1834981A (en) * 1928-04-02 1931-12-08 Albert H Stebbins Air classifier
FR43404E (fr) * 1933-02-04 1934-06-06 Cadre trieur pour olives
US3044619A (en) * 1958-12-04 1962-07-17 Knolle Wilhelm Apparatus for sorting seed material
SU732033A1 (ru) * 1977-03-11 1980-05-05 Харьковский Институт Механизации И Электрификации Сельского Хозяйства Вибрационна очистительно-сортировальна машина дл разделени зерновых смесей по коэффициенту парусности

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10272A (en) * 1853-11-29 gritzner
FR336106A (fr) * 1903-10-17 1904-02-29 Leon Bloume Système de classement de toutes matières par volume et densité
US846140A (en) * 1906-10-22 1907-03-05 Louis F Lumaghi Coal screening and grading apparatus.
US916625A (en) * 1907-12-04 1909-03-30 Robert Stein Separator.
GB284546A (en) * 1927-07-11 1928-02-02 Gerald Petrie Improvements relating to apparatus for sorting and grading refuse and other mixed materials
US1834981A (en) * 1928-04-02 1931-12-08 Albert H Stebbins Air classifier
FR43404E (fr) * 1933-02-04 1934-06-06 Cadre trieur pour olives
US3044619A (en) * 1958-12-04 1962-07-17 Knolle Wilhelm Apparatus for sorting seed material
SU732033A1 (ru) * 1977-03-11 1980-05-05 Харьковский Институт Механизации И Электрификации Сельского Хозяйства Вибрационна очистительно-сортировальна машина дл разделени зерновых смесей по коэффициенту парусности

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5400908A (en) * 1993-07-26 1995-03-28 Prestwood; James R. Method and apparatus for separating materials of different weights
CN113499989A (zh) * 2021-07-23 2021-10-15 西安赛隆金属材料有限责任公司 一种用于球形空心粉末的分选装置及方法

Similar Documents

Publication Publication Date Title
US5032256A (en) Method and apparatus for air separation of material
US4519896A (en) Dry material sorting device
US4851110A (en) Air pump separator method and apparatus
US7708145B2 (en) Dry separating table, a separator and equipment for the compound dry separation with this table
CA2062825C (fr) Procede de triage par flottation d'objets de densites legerement differentes et dispositif correspondant
US3164548A (en) Tower type pneumatic separator
US4213852A (en) Method and apparatus for particle classification
US4950388A (en) Separation of mixtures in a wind tunnel
US4089422A (en) Air classifier
EP0267948A1 (fr) Procede et appareil de separation
AU570554B2 (en) Dry material sorting device
US4946584A (en) Hydraulic product separator
US4137155A (en) Method of and apparatus for pneumatically sorting heterogeneous mixtures
US4849099A (en) Particle feeding apparatus
WO1986005420A1 (fr) Appareil de triage de materiaux secs
US2635745A (en) Apparatus for separating a mixture of granular or comminuted materials by air suspension
CA1235387A (fr) Dispositif de tri de matieres seches
US3108950A (en) Separator apparatus
CA2420306C (fr) Dispositif permettant de repartir des copeaux de bois en fractions distinctes
CA1116558A (fr) Separateur par derivation pour melange de sable et de fine terre vegetale
EP0395675A1 (fr) Procede et appareil de classage de particules
US5191981A (en) Specific gravity metal separator
US2717692A (en) Mineral concentrators
RU2672697C1 (ru) Способ для разделения сыпучих материалов по фракциям методом метания смеси частиц с одинаковой скоростью и устройство для его осуществления
JPH01274858A (ja) サイクロン分別方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): CF CG CM GA ML MR SN TD TG