METHOD AND DEVICE FOR THE RAPID MEASUREMENT OF THE MASS AND CONCENTRATION OF PARTICLES

• US 3,844,174 A
• Filed: 10/12/1972
• Issued: 10/29/1974
• Est. Priority Date: 10/18/1971
• Status: Expired due to Term

• Current Assignee: Andre Paul Chabre
• Original Assignee: Andre Paul Chabre
• Inventors: Chabre, Andre Paul
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Roskos, Joseph W.
• Application Number:
  US05/296,944
• Time in Patent Office: 747 Days
• Field of Search: 73/432PS,61R,28,23,194B,11,12,DIG.4,17R,432R 324/71CP 310/8.7 340/191,236
• US Class Current: 73/865.5
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 2291/02408 Solids in gases, e.g. particle suspensions
• CPC Class Codes: G01N 2291/02416 Solids in liquids
• CPC Class Codes: G01N 29/046 using the echo of particles imparting on a surface; using acoustic emission of particles investigating concentration of particle suspensions G01N15/06; devices for measuring flow of solids in suspension G01F1/74
• CPC Class Codes: Y10S 73/04 Piezoelectric

Abstract

Particles contained in a fluid are set in motion and guided onto the sensitive face of a piezoelectric detector at an oblique angle of incidence and the relative velocity of the particles with respect to the detector is determined. The amplitudes and number of electrical signals delivered by the detector under the impact of the particles are measured and provide the masses and concentration respectively of said particles after calibration of said detector.

Claims

1. A method of measuring the mass and concentration of particles contained in a fluid, comprising the steps of causing a fluid containing particles to collide with the face of a piezoelectric detector at an oblique angle of incidence by moving said detector at a predetermined speed and with a predetermined inclination of the face thereof with respect to the direction of movement, determining the relative velocity of said particles with respect to said detector, measuring the amplitude and number of electrical signals produced by said detector under the impact of said particles to provide an indication of the masses and concentration of said particles.

2. A method of measuring a mass and concentration of particles contained in the fluid, comprising the steps of causing the fluid containing particles to collide with the face of a piezoelectric detector at an oblique angle of incidence by impelling said fluid at a predetermined speed and direction with respect to said detector such that said particles collide with the face of said detector at said oblique angle of incidence, determining the relative velocity of said particles with respect to said detector, measuring the amplitude and number of electrical signals produced by said detector under the impact of said particles to produce an indication of the masses and concentration of said particles.

3. The method of claim 2, wherein the step of determining said velocity includes measuring the rate of flow of said fluid with respect to said detector.

4. Apparatus for measuring the mass and concentration of particles contained in a fluid, comprising a piezoelectric probe with a sensitive fAce for producing electrical impulses when said face is struck by particles, means for impelling a fluid containing particles in a predetermined direction toward the face of said probe, said sensitive face being oriented obliquely with respect to said predetermined direction of said fluid, means producing an output indicative of the velocity of said particles relative to said probe, and a measurement system responsive to said output indicative of velocity and to the number and amplitude of said electrical impulses for indicating the concentration and masses of said particles.

5. The apparatus of claim 4, wherein said means for impelling said fluid includes a channel leading to said sensitive face and means to drive said fluid down said channel toward said face.

6. The apparatus of claim 4, wherein said means for producing an output indicative of velocity includes a flowmeter located upstream of said detector.

7. The apparatus of claim 4, wherein said measurement system includes an amplifier and a multichannel amplitude analyzer.

8. Apparatus for measuring the mass and concentration of particles contained in a fluid, comprising a piezoelectric probe with a sensitive face for producing electrical impulses when said face is struck by particles, means for impelling a fluid containing particles in a predetermined direction toward the face of said probe, means producing an output indicative of the velocity of said particles relative to said probe, and a measurement system responsive to said output indicative of velocity and to the number and amplitude of said electrical impulses for indicating the concentration and masses of said particles, said probe including a piezoelectric detector contained in the bottom of a hollow metallic cylinder, the axis of said detector being oblique with respect to the axis of said cylinder, a conductive layer electrically connecting the sensitive face of said detector with said metallic cylinder, a lead wire interconnecting the opposite face of said detector to said measurement system.

9. The apparatus of claim 8, wherein said conductive layer is an electrodeposited metal coating.

10. The apparatus of claim 8, wherein said metallic cylinder is filled with an elastic electrically insulating material.

11. Apparatus for measuring the mass and concentration of particles contained in a fluid, comprising a piezoelectric probe with a sensitive face for producing electrical impulses when said face is struck by particles, means for impelling a fluid containing particles in a predetermined direction toward the face of said probe, means producing an output indicative of the velocity of said particles relative to said probe, and a measurement system responsive to said output indicative of velocity and to the number and amplitude of said electrical impulses for indicating the concentration and masses of the said particles, said probe including two piezoelectric detectors operatively mounted to act in opposition, one of said detectors providing said sensitive face.