Spiral Sand Washing Machine

Effective Clay & Silt Removal, High Sand Cleanliness

The slowly rotating screw continuously agitates and scrubs sand particles against each other and against the screw blade surface in the water-filled washing pool, breaking down clay coatings on individual sand particle surfaces and releasing fine silt and dust particles into the wash water. The overflow water carries these liberated clay, silt, and fine contaminants over the adjustable weir at the lower end of the trough while clean sand is retained and conveyed upward, producing consistently clean, clay-free sand that meets the most stringent cleanliness specifications for high-grade concrete and asphalt aggregate applications.

Low Fine Sand Loss, Controlled Grading

Unlike high-energy attrition scrubbers or hydraulic classifiers that can wash away significant proportions of fine sand particles along with contaminants, the Spiral Sand Washing Machine uses gentle screw agitation and a controlled overflow weir height to separate only clay, silt, and particles finer than the target cut size — typically below 0.075–0.15 mm — while retaining the majority of commercially valuable fine sand particles in the product. This selective washing action minimizes fine sand loss, maximizing product yield and commercial value per tonne of feed material processed.

Simultaneous Washing, Grading & Dewatering

The single Spiral Sand Washing Machine performs three process functions simultaneously: washing clay and silt from the sand surface; grading the washed sand by removing particles finer than the set cut size over the overflow weir; and partially dewatering the washed sand as it rises above the water level on the inclined screw and drains before discharge at the upper end. This multi-function operation eliminates the need for separate scrubbing, classification, and dewatering equipment stages, significantly reducing plant capital cost, footprint, and operating complexity.

Robust Heavy-Duty Construction for Continuous Operation

The trough is fabricated from 8–12 mm carbon steel plate with full-penetration welds on all structural joints and wear-resistant rubber or polyurethane lining on all internal surfaces in contact with wet sand and aggregate, providing corrosion protection and abrasion resistance simultaneously. The screw shaft and blade assembly is designed for continuous 24-hour operation under full load, and the sealed bearing assemblies at both ends of the screw shaft use grease lubrication with extended re-greasing intervals, eliminating daily lubrication requirements and reducing routine maintenance to a minimum.

Adjustable Weir Height for Flexible Grading Control

The height of the overflow weir at the lower end of the trough is adjustable via bolted weir plate inserts or a sliding weir gate, allowing the water level in the washing pool — and therefore the grading cut point and fine removal efficiency — to be adjusted without stopping the machine or modifying the drive system. Raising the weir increases water depth, extending particle residence time and removing finer particles; lowering the weir reduces water depth and retains more fine sand in the product. This adjustability allows a single machine to produce sand meeting different gradation zone specifications by simple weir height adjustment.

Simple Structure, Easy Maintenance, Long Service Life

The Spiral Sand Washing Machine has no complex sealed chambers, high-pressure systems, or precision-clearance moving parts — the rotating screw, the trough, the drive head, and the overflow weir are the primary components. This mechanical simplicity results in very low scheduled maintenance requirements, straightforward on-site repair using standard workshop equipment, and long service life with typical major overhaul intervals of 3–5 years under continuous operation. Screw blade wear inserts and trough lining replacement are the primary wear maintenance tasks, both performable by plant maintenance crews without specialist contractor support.