Introduction

Date: 2015-10-07; view: 494.

Article Outline

1. Introduction

1.1. Acoustic force field

1.2. Primary axial acoustic force

1.3. Primary and secondary acoustic force

2. Application of Newton's second law

3. Mathematical model

3.1. Preliminary analysis

4. Equation for particle trajectories

5. Concentration equation

6. Experimental procedure and results

6.1. SiC particle trajectories in an acoustic field

7. Comparison between experimental results and mathematical model

8. Summary and conclusions

Acknowledgements

References

It is difficult to fractionate ultra-fine particles and particles with neutral buoyancy, or uniform electro-magnetically charged surfaces. Existing methods are extremely slow or require prohibitive pressure drops, or extremely high electric or magnetic fields. Hence this exploratory research (cf. [1] and [2]) using acoustic and flow fields was conducted to evaluate the feasibility of fractionating ultra fine suspended particles and at the same time segregating them. In this technology the particle movements due to density and compressibility differences between fluid and particles rather than the particle size are used to fractionate ultra-fine suspended particles. In the following section, the basic derivation for particles in equilibrium in an acoustic field is given, which will be used for the derivation of particle trajectory and concentration equations.