Screw washers are used for transporting the washed products by dewatering during the screening stage in crushing and screening plants. They may be produced single and double screw.
What Is a Screw Sand Washer and How Does It Work?
A screw (spiral) washer consists of slowly rotating screw flights inside an inclined tank. Sand is fed with water to the lower end; as the screw conveys the sand upwards, clay, silt and light contaminants are carried away with the water over the overflow weir.
The sand leaves the top washed and partly dewatered, meeting the cleanliness and fines limits required for concrete and mortar sand.
Applications
- Washing river sand and manufactured sand
- Producing concrete and plaster sand
- Cleaning material containing clay and silt
- Sand and gravel pits
Selection Checklist
- Tank length and screw diameter chosen for capacity
- Water quantity and weir height determine the fine size lost
- Screw flights protected against wear
- Thickener and filter press planned for waste water
Main Spare Parts for Screw Sand Washers
- Screw flights and wear shoes
- Lower (submerged) bearing and seals
- Gear reducer and electric motor
- Bearings
Frequently Asked Questions
Does a screw washer lose fine sand?
If water quantity and weir setting are wrong, fine sand is lost with the overflow; a hydrocyclone and dewatering screen can recover it.
What is the most common screw washer failure?
Water and sand entering the submerged lower bearing through damaged seals; check seals and grease regularly.
Detailed guides: screw sand washer, sand and gravel plants.