Spiral classifier is a widely used solid-liquid separation equipment in mineral processing, building materials, chemical industry and other industries. Its core function is to realize the particle size classification of material particles through the rotational movement of spiral blades.This article will systematically analyze the technical characteristics of this equipment from the aspects of structure composition, working principle, grading process and influencing factors.

1. Equipment structure and basic composition

    The spiral classifier is mainly composed of the following components：

    Spiral blade: installed obliquely in the tank body, and thrust is generated by rotation to push the material up along the tank body.

    Graded tank body: it is designed in a U-shaped or V-shaped shape, with a sedimentation area at the bottom and an overflow area at the upper part.

    Transmission device: drive the spiral blade to rotate, and the speed is adjustable to adapt to different material characteristics.

    Lifting mechanism: used to adjust the spacing between the spiral blade and the bottom of the groove and control the grading accuracy.

2. Grading process and working principle

    Feeding and sedimentation

    The slurry enters from one end of the tank, the coarse particles quickly settle to the bottom of the tank due to gravity, and the fine particles rise to the overflow port with the water flow.

    Spiral push effect

    The rotating spiral blades push the deposited coarse particles upward, forming a "return sand”, while preventing the fine particles from mixing.

    Particle size separation mechanism

    Difference in sedimentation speed: Fine particles are suspended and rise by the action of water flow, while coarse particles are trapped because the sedimentation speed is greater than the rising water flow speed.

    Hydraulic grading effect: The slope of the tank body and the spiral rotation speed jointly affect the critical particle size of the separation.

3. Analysis of key influencing factors

    Spiral speed: Too high speed will cause fine particles to be forced to be pushed, reducing the grading efficiency.

    The inclination of the tank body: it is usually designed to be 12°-18°, and the increase of the inclination can improve the processing capacity of coarse particles.

    Slurry concentration: Too high concentration can easily cause particle agglomeration, which affects the accuracy of grading.

4. Application scenarios and optimization suggestions

    The equipment is suitable for the grading of iron ore, copper ore and other metal minerals. Optimization measures include：

    Regularly check the wear of spiral blades

    Dynamically adjust the speed and inclination angle according to the material characteristics

    Cooperate with hydrocyclone to achieve multi-stage classification

Conclusion

    The spiral classifier realizes efficient particle size separation through mechanical and hydraulic synergy, and its performance directly affects the efficiency of the subsequent mineral processing process.Understanding its working principle and optimizing operating parameters are the key to improving the production capacity of the production line.