WO1995011429A1 - Appareil et procede de surveillance du debit massique de matieres solides - Google Patents

Appareil et procede de surveillance du debit massique de matieres solides Download PDF

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Publication number
WO1995011429A1
WO1995011429A1 PCT/US1993/009955 US9309955W WO9511429A1 WO 1995011429 A1 WO1995011429 A1 WO 1995011429A1 US 9309955 W US9309955 W US 9309955W WO 9511429 A1 WO9511429 A1 WO 9511429A1
Authority
WO
WIPO (PCT)
Prior art keywords
housing
particulate material
solid particulate
flux
flow rate
Prior art date
Application number
PCT/US1993/009955
Other languages
English (en)
Inventor
William Jefferson Mccown
Original Assignee
E.I. Du Pont De Nemours And Company
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
Priority to US07/801,920 priority Critical patent/US5253535A/en
Priority claimed from US07/801,920 external-priority patent/US5253535A/en
Application filed by E.I. Du Pont De Nemours And Company filed Critical E.I. Du Pont De Nemours And Company
Priority to AU54442/94A priority patent/AU5444294A/en
Priority to PCT/US1993/009955 priority patent/WO1995011429A1/fr
Publication of WO1995011429A1 publication Critical patent/WO1995011429A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
    • G01F1/86—Indirect mass flowmeters, e.g. measuring volume flow and density, temperature or pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G53/00—Conveying materials in bulk through troughs, pipes or tubes by floating the materials or by flow of gas, liquid or foam
    • B65G53/34—Details
    • B65G53/40—Feeding or discharging devices
    • B65G53/46—Gates or sluices, e.g. rotary wheels
    • B65G53/4608—Turnable elements, e.g. rotary wheels with pockets or passages for material
    • B65G53/4625—Turnable elements, e.g. rotary wheels with pockets or passages for material with axis of turning perpendicular to flow
    • B65G53/4633—Turnable elements, e.g. rotary wheels with pockets or passages for material with axis of turning perpendicular to flow the element having pockets, rotated from charging position to discharging position, i.e. discrete flow
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F11/00—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it
    • G01F11/10—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation
    • G01F11/12—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements
    • G01F11/20—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements wherein the measuring chamber rotates or oscillates
    • G01F11/24—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements wherein the measuring chamber rotates or oscillates for fluent solid material

Definitions

  • the invention relates to an apparatus and method for monitoring the mass flow rate of particulate solids, particularly, titanium dioxide.
  • U.S. Patent 4,520,677 discloses a method and apparatus for indicating mass flow of a solid particulate material through a star wheel rotary feeder.
  • Such feeders include a plurality of vanes extending radially from a rotating shaft, mounted within a housing, to form a plurality of rotating pockets which receive, transport through the housing, and subsequently discharge solid particulate material.
  • the apparatus utilizes a source for discharg ⁇ ing a radiation flux positioned within the rotating shaft. The radiation flux is discharged toward a detector, through the shaft and pockets containing the solid particulate material.
  • This invention provides an apparatus and method for calculating mass flow rate of solid particulate material through a rotary feeder.
  • the apparatus comprises a rotary feeder having a rotatable shaft mounted within a housing.
  • the rotatable shaft has a plurality of vanes extending helically therefrom forming helical pockets which receive, transport and subsequently discharge solid particulate material.
  • the housing contains a housing inlet for receiving the solid particulate material into the helical pockets and a housing outlet through which the solid particulate material is discharged from the helical pockets.
  • the rotatable shaft is operationally connected to a means for rotating the rotatable shaft.
  • the apparatus further comprises a flux discharging radiation source disposed within the rotatable shaft, a first and second flux- radiation detectors disposed externally of uhe housing, means for measuring the flux radiation received by the detectors and converting the measurements to electrical signals for trans ⁇ mitting, means for measuring rate of rotation of the rotatable shaft and converting the measurement to an electrical signal for transmitting; a means for calculating mass flow rate of particulate solid material based on the signals received from the means for measuring the flux radiation received by the detectors and the means for measuring rate of rotation; and a means for displaying the calculated mass flow rate.
  • the first detector is disposed downstream of the housing inlet and upstream of the housing outlet, i.e., where the pocket is filled with solid particulate material.
  • the second detector is disposed downstream of the housing outlet and upstream of the housing inlet, i.e., where the pocket has discharged the solid particulate material.
  • a known amount of flux radiation is discharged from the source toward the first and second detectors.
  • the flux radiation therefore passes through each pocket twice during rotation, once in the filled position and again in the discharged position.
  • the amount of flux radiation received at the first and second detectors is measured.
  • the shaft and helical pockets is measured.
  • the measurements are converted to electrical signals and are transmitted to the means for calculating the mass flow rate.
  • the means for calculating the mass flow rate can accurately determine the actual mass discharged.
  • the method uses the accurate mass determination and the measurement of rotation of the shaft to calculate an accurate mass flow rate which is then displayed.
  • FIG.l is a side elevation, in section, of an apparatus of the invention.
  • FIG.2 is a top view of the device of FIG. 1.
  • the feeder 10 includes a housing 12 within which is mounted a rotatable shaft 14. Helically extending from the shaft are a plurality of vanes 16 which form within the housing a plurality of helical pockets 18. The helical pockets 18 are bounded laterally by side walls 19 of the vanes.
  • the housing is generally affixed to an inlet conduit 20 and an outlet conduit 22 through which flow a solid particulate material 24 such as titanium dioxide. The particulate material 24 does not consistently display free flowing characteristics.
  • the housing 12 has a housing inlet 26 for receiving solid particulate material 24 into the helical pockets 18 and a housing outlet 28 through which the solid particulate material 24 is discharged from the helical pockets 18.
  • the shaft 14 is rotated by a rotating means, not shown, thereby rotating the vanes 16 and helical pockets 18 to transport solid particulate material 24 from the housing inlet 24 to the housing outlet 28.
  • the rotating means is a motor coupled with a gear mechanism to enable the rate of rotation to be controlled by the operator.
  • the apparatus has a means, not shown, for measuring the rate of rotation of the shaft 14 and helical pockets 18.
  • the means is a tachometer.
  • the flux radiation is directed from the source 32 through the shaft 14, pockets 18 and vanes 16 and housing 12 to flux radiation detectors 34A and 34B.
  • the flux radiation source is Cesium-137 which provides excellent penetration through the shaft 14, vanes 16 and housing 12 and through the solid particulate material 24.
  • the amount of flux radiation and number of flux radiation sources required is established by analyzing parameters such as composition and thickness of the shaft 14, vanes 16, and housing 12 , the density of the solid particulate material 24 and the span. Multiple flux radiation sources of differing strengths may be required to achieve a uniform flux radiation field intensity at the face of the detector. The determination of individual source strength, plurality and spacing between sources is application dependent and is largely governed by the physical dimensions of the feeder pocket width and separation between radioactive source and detector.
  • the radiation source material is placed in a suitable holder surrounded with lead in all directions except where the radiation is colli ated and beamed to detectors 34A and 34B.
  • the lead effectively blocks radiation to a safe field intensity level which complies with applicable national and international standards.
  • the flux radiation is attenuated during passage to a degree which is a function of the mass of the shaft 14, vane 16 and housing 12, and the solid particulate material 24 contained within the helical pocket 18.
  • the detectors which are highly sensitive and stable, preferably consist of an ionization chamber and, more preferably, include a pre-amplifier.
  • the detectors are mounted directly opposite a directed beam from the radiation source. The detectors extend the length of the pockets as does the collimated flux radiation.
  • the detectors 34A and 34B As the flux passes from the source 32 to the detectors 34A and 34B, indicated by the dotted lines LI and L2, it is attenuated by any material in its path.
  • the detectors receive the attenuated collimated beam of flux radiation and generate an electrical signal, preferably a low impedance voltage signal, inversely proportional to the mass of the material through which the beam passed.
  • the electrical signal from the detectors 34A and 34B and the means for measuring the rate of rotation of the shaft is provided to a means for calculating mass flow rate, not shown, which analyzes the signals.
  • the calculating means is preferably a remote electronic monitor having a calculating and displaying means.
  • the detectors, means for measuring rotation and monitor are integrated to yield the quality of solid particulate material retained within a given pocket after discharge of the solid particulate material.
  • the monitor compares the value of the signal received from the first detector at the filled position with the value of the signal received from the second derector at the discharged position to determine the mass of solid particulate material actually discharged from a given pocket.
  • the difference between the determined mass contained in a given pocket in its full and discharged positions provides an accurate measure of the mass of solid particulate material discharged from the feeder. This determination takes into account the amount of material left in the pocket subsequent to discharge of most of the contained solids particulate material.
  • the mass determined is multiplied by the flow rate as measured by the means for measuring the rotation rate to provide the mass flow rate of the solid particulate material.
  • the mass flow rate is preferably displayed on a digital readout.
  • the inventors have found this apparatus and method to be of particularly advantage for use in measuring the transport of titanium dioxide which has a tendency to adhere to the pockets.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Measuring Volume Flow (AREA)

Abstract

Procédé et appareil permettant de transporter des matières particulaires solides et de calculer le débit massique des matières particulaires par l'intermédiaire d'un dispositif d'alimentation rotatif muni de chambres hélicoïdales. Au moins une source de rayonnement et au moins deux détecteurs sont positionnés de façon qu'un flux de rayonnement soit dirigé à travers les matières particulaires contenues dans une chambre hélicoïdale et atténué par lesdites matières. On mesure le niveau d'atténuation au moins lorsque la chambre est remplie par les matières particulaires et lorsqu'elle en a évacué la majeure partie. On utilise la différence entre les niveaux de flux détectés lorsque la chambre est remplie et lorsqu'elle est vide pour déterminer le débit massique des matières particulaires.
PCT/US1993/009955 1991-12-03 1993-10-19 Appareil et procede de surveillance du debit massique de matieres solides WO1995011429A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US07/801,920 US5253535A (en) 1991-12-03 1991-12-03 Apparatus and method for monitoring mass flow of solids
AU54442/94A AU5444294A (en) 1991-12-03 1993-10-19 Apparatus and method for monitoring mass flow of solids
PCT/US1993/009955 WO1995011429A1 (fr) 1991-12-03 1993-10-19 Appareil et procede de surveillance du debit massique de matieres solides

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/801,920 US5253535A (en) 1991-12-03 1991-12-03 Apparatus and method for monitoring mass flow of solids
PCT/US1993/009955 WO1995011429A1 (fr) 1991-12-03 1993-10-19 Appareil et procede de surveillance du debit massique de matieres solides

Publications (1)

Publication Number Publication Date
WO1995011429A1 true WO1995011429A1 (fr) 1995-04-27

Family

ID=26787072

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1993/009955 WO1995011429A1 (fr) 1991-12-03 1993-10-19 Appareil et procede de surveillance du debit massique de matieres solides

Country Status (2)

Country Link
AU (1) AU5444294A (fr)
WO (1) WO1995011429A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT501790A1 (de) * 2005-04-20 2006-11-15 Helmut Simon Ing Orgler Zellenradschleuse, für grosses schüttgut mit geringer antriebsleistung

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2273909A1 (fr) * 1974-06-04 1976-01-02 Linden Alimak Ab Dispositif d'alimentation pour un agent de stabilisation du sol
EP0042245A1 (fr) * 1980-06-14 1981-12-23 Claydon Yield-O-Meter Limited Dispositif de mesure de grains pour moissonneuses-batteuses
EP0079421A1 (fr) * 1981-10-30 1983-05-25 KRW Energy Systems Inc. Indicateur d'un flux massique de matériaux solides
DE3417583A1 (de) * 1984-05-11 1985-11-21 Endress U. Hauser Gmbh U. Co, 7867 Maulburg Anordnung zur massedurchsatzmessung

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2273909A1 (fr) * 1974-06-04 1976-01-02 Linden Alimak Ab Dispositif d'alimentation pour un agent de stabilisation du sol
EP0042245A1 (fr) * 1980-06-14 1981-12-23 Claydon Yield-O-Meter Limited Dispositif de mesure de grains pour moissonneuses-batteuses
EP0079421A1 (fr) * 1981-10-30 1983-05-25 KRW Energy Systems Inc. Indicateur d'un flux massique de matériaux solides
US4520677A (en) * 1981-10-30 1985-06-04 The United States Of America As Represented By The United States Department Of Energy Solids mass flow indication with radiation
DE3417583A1 (de) * 1984-05-11 1985-11-21 Endress U. Hauser Gmbh U. Co, 7867 Maulburg Anordnung zur massedurchsatzmessung

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT501790A1 (de) * 2005-04-20 2006-11-15 Helmut Simon Ing Orgler Zellenradschleuse, für grosses schüttgut mit geringer antriebsleistung
AT501790B1 (de) * 2005-04-20 2008-01-15 Helmut Simon Ing Orgler Zellenradschleuse zur förderung von schüttgut

Also Published As

Publication number Publication date
AU5444294A (en) 1995-05-08

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