Sample supplying device for a dry particle-size distribution measuring apparatus and method

• US 20030147074A1
• Filed: 12/18/2002
• Published: 08/07/2003
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: Horiba Limited
• Original Assignee: Horiba Limited
• Inventors: Kitamura, Hiroyuki, Yamaguchi, Tetsuji
• Granted Patent: US 7,042,557 B2
• Time in Patent Office: Days
• US Class Current: 356/336
• CPC Class Codes: G01N 15/0205 by optical means
• CPC Class Codes: G01N 2015/0096 Investigating consistence of powders, dustability, dustiness

Abstract

A dry particle-size distribution measuring apparatus and method is provided for suspending a plurality of bristle members across a support surface of a dispensing trough with bristles being arranged to contact and disperse any clusters of particles to a primary state prior to releasing the particles to a sample flow cell. A source of light can irradiate the sample flow cell and a detector unit can measure any scattered and/or diffracted light to provide corresponding signals. A control unit can determine the size and distribution of particles from the corresponding signals. The bristle members can be mounted on a brush unit that is directly mounted on the trough and both the trough and the brush unit can be driven by the same vibrator unit.

Claims

1. In a sample supplying device for a dry particle-size distribution measuring apparatus which is configured by a trough that accommodates a sample, and a linear feeder that vibrates said trough, and in which the sample in said trough is dropped through a sample drop hole formed in said trough, by vibrating said trough, the improvement comprising:

a brush unit operatively positioned in said trough and vibrated by the vibration of the trough to contact and disperse the sample to a primary particle state before being dropped through the sample drop hole.

2. The sample supply device of claim 1, wherein the sample contains particles of approximately 1 μ

m in size and the brush unit includes bristles that are spaced greater than 1 μ

m in distance apart.

3. The sample supply device of claim 2, wherein the brush unit includes a cylindrical base with bristles extending 360°

around the base.

4. The sample supply device of claim 1, further including a mounting unit for mounting the brush unit to provide both vertical and horizontal movement in said trough.

5. The sample supply device of claim 1, wherein the brush unit includes bristles that are progressively positioned closer to each other the closer to the sample drop hole.

6. The sample supply device of claim 1, wherein the brush unit includes bristles that are positioned in an elongated arrangement across said trough.

7. The sample supply device of claim 1, wherein the brush unit includes bristles arranged in rectangular pattern with center devoid of bristles.

8. A method of separating particles into a primary state in a particle-size distribution measuring apparatus, comprising the steps of:

supplying a sample of particles to a support surface;

vibrating the support surface while moving the sample of particles along the support surface; and

contacting the sample of particles with a plurality of bristles that vibrate relative to the support surface, the arrangement of bristles being spaced to assure contact with any cluster of particles attached together whereby the bristles will contact and disperse the cluster of particles to a primary state so that the sample of particles will be in a primary state after contact with the bristles.

9. The method of claim 8, wherein the sample of particles are approximately 1 μ

m in size.

10. The method of claim 8, wherein the bristles are vibrated in a vertical and horizontal direction relative to the support surface.

11. The method of claim 8, wherein the bristles are mounted on the support surface and are vibrated by the vibration of the support surface.

12. A dry particle-size distribution measuring apparatus comprising:

a sample supplying device having a support surface for holding a sample of particles to be measured and a dispersing position for releasing the sample of particles from the support surface including;

a vibrator unit for vibrating the support surface;

a plurality of bristle members spaced across the support surface upstream of the dispersing portion, wherein the distance between bristles are arranged to contact and disperse any cluster of particles to a primary state so that the sample of particles will be in a primary state after contact with the bristles;

a sample flow cell for receiving the sample of particles from the dispensing portion;

a source of light for irradiating the sample flow cell;

a detector unit for measuring the scattered and/or diffracted light and providing corresponding signals; and

a control unit for determining the size of particles from the corresponding signals.

13. The dry particle-size distribution measuring apparatus of claim 12, wherein the sample contains particles of approximately 1 μ

m in size and the bristles are spaced greater than 1 μ

m in distance apart.

14. The dry particle-size distribution measuring apparatus of claim 13, wherein the bristles extending 360°

around a cylindrical base.

15. The dry particle-size distribution measuring apparatus of claim 12, further including a brush unit for mounting the bristles to provide both vertical and horizontal movement in said trough.

16. The dry particle-size distribution measuring apparatus of claim 15, wherein the brush unit includes bristles that are progressively positioned closer to each other the closer to the dispensing portion.

17. The dry particle-size distribution measuring apparatus of claim 15, wherein the brush unit includes bristles that are positioned in an elongated arrangement across said trough.

18. The dry particle-size distribution measuring apparatus of claim 15, wherein the brush unit includes bristles arranged in rectangular pattern with center devoid of bristles.

19. The dry particle-size distribution measuring apparatus of claim 15, wherein the vibrator unit includes a pair of plate spring members.

20. The dry particle-size distribution measuring apparatus of claim 19, wherein the plurality of bristle members are mounted on a brush unit supported by the support surface so that the vibrator unit also vibrates the plurality of bristle members.