for applications where you're wanting to move material out of a liquid. The open center allows the fluid to remain in place while the material is extracted. I've seen them used in large machining equipment to extract shavings from the cutting lubricant/coolant, but they are also popular in sewage treatment facilities as well.

Have you ever seen a shaft conveyor try to bend around a slight incline , obviously impossible , However it can be done with a spring steel shaftless screw .Also you have no clogging or wrapping of debris when dealing with screening . They are more expensive however .

Below a list of the main benefits to the shaftless spiral conveyors: - Intended for the transport of difficult, stringy, spongy, sticky, wet, lumpy materials - suitable for a wide range of moisture contents and viscosities. - The shaftless spiral conveyor has a high volume capacity for a small cross section. - No intermediate or end bearings. - Complex geometries and limited space easily satisfied. - High resistance to corrosion provides for very long equipment life expectancy in the harshest of conditions. - Low RPM for long life expectancy. - Liners are the only wear component in a shaftless screw conveyor. The DURAFLO® Type SPX liner has a built-in wear indicator with a snap-in, snap-out feature, making it as painless as possible when the time comes to replacing the liner. - Totally enclosed troughs for odor and mess containment. - Very high load/torque capability. - Low maintenance costs. - Long continuous runs on a single gearbox. - Easily able to handle large foreign objects or product lumps. - The forgiving operation allows for a wide capacity range. - Custom designed to match field equipment.

Yes, you can transport dry river sand with shaftless spiral conveyors.