Spiral dewaterers

Metso's spiral dewaterer consists basically of an open trough with arrangements for collection of the products.
The inlet flow is evenly spread out by means of a feed distributor. Coarse material settles and is continuously removed by means of the transport spiral. The material will be dewatered by drainage in the upper part of the spiral before discharge.

The discharge launder for the dewatered material is easily adjusted between two positions, allowing alternative discharge into two separate bins. The clarified water passes an overflow weir which is adjusted at start-up to give even distribution of flow over the full width of the trough. A baffle plate will prevent floating materials from being drawn by the clarified water discharge.

The spiral dewaterer is suitable for:

• Mill scale treatment in continuous casting, hot rolling and scarfing
• Coarse material dewatering

Main benefits of the spiral dewaterer:

• Competitive price
• Assembly and installation friendly
• Fewer components
• New lamella pack design
• High strength
• ”Self supporting”

Main features of the spiral dewaterer:

• Separate bolted assembly details designed for easy erection
• No assembly welding at erection
• No after work such as painting
• Easy erected components prepared with fixed lifting points
• One lamella package with straight vertical fit
• Part dimensions suitable for 40’ Container transport

Washing effluents coming from the steel industry with high flows and a low to moderate content of well defined solids like mill scales and slag has been proven optimal for the spiral dewaterer. In the sedimentation tank the wash water is reclaimed and sent back to the washing operation again.
The solids are removed by and dewatered in the discharge spiral and can be sent to recycling if this is considered of value.