M Sand manufacturing takes places through many stages, Sand classifier is one such stage, where if any larger sand particles found are removed here. Sand classifier are of two types, Dry sand classifier and Wet sand classifier.
1. Dry Classifier
Heaviest particle mainly + 150 microns - 5 mm not ascending will fall to the bottom of the inner cone and on to a chute and stock plied on the ground through a conveyor belt. which is classified Sand conforming to the standards prescribed in IS 383.
Air velocity, volume of Air and speed of Rotation are important factors to achieve the good separation of fines from heavier particles. The Moisture content in the input material. As per the available data it can operate up to 2-3% moisture by weight in the feed material.
- Conserves water – As no water is required.
- As a closed system – no Pollution.
- Ease of operation & economical as low operating cost.
- Quality - With variable speed can monitor the fines content.
2. Wet Classifier:
The dry feed material 0-5 mm from the crushing plant and water is added in to the fabricated tank equipped with slow moving screw where decantation takes place with low turbulence flow.
Water with (-) 150 microns will be carried away by the flowing water moves in the opposite side and collected in weir and discharged outside.
The washed /Classified cleaned sand, through rotation of the screw against the water stream flow. The cleaned sand will be lifted by the rotating bucket wheel fall on the DE watering screen.
The slotted perforations in the special screen deck allows to remove water from the washed sand and water goes back in to the washing process. The cleaned & DE watered sand falls on to belt conveyor and to stock.
- Does not cause any air pollution
- Silt and other impurities are completely removed
- Since its water washed it uses less water while mixing mortars