Multi disc screw press dehydrator / Sludge drying, Recycling drying

There are a lot of kinds of dehydrator for sludge arises from wastewater treatment plants. Among them, multi disc screw press dehydrator is a dehydrator which has function of both multi disc dehydrator and screw press dehydrator together. While screws rotate, sludge is filtered and dehydrated from gaps between filtering devices which is configured with moving discs and fixed discs surrounding the screws.
 

Multi disc screw press dehydrator has configuration with screw surrounded by filtering devices which have moving discs and fixed discs combined together and lined up. As screw rotates, screw filters and dehydrates sludge while it is conveying sludge. Moving disk of the filtering device is moved upward as screw rotates and water was discharged from the gap made between the moving disc and fixed disc, so that sludge is filtered and dehydrated.
The space between the screw and filtering device configured by fixed disc and moving disc becomes narrower as it comes nearer to outlet. Pressure which squeeze sludge become bigger as the sludge moves toward to the outlet, so that the sludge is filtered and dehydrated tightly. Also, more sludge particles flew out together with water as sludge get closer to outlet because of increased squeezing pressure though, gap between moving disc and fixed disc around the screw becomes narrower as they get closer to outlet and sludge particles are prevented to be flew out.
This type of dehydrator doesn’t need cleaning since moving disc in the filtering device is always being moved by the rotating screws and clogging never happen. Therefore, in some wastewater treatment plants, waste sludge pulled out from aeration tank can be dehydrated directly without condensation. Polymer flocculation is used in conditioning before the dehydration.

About types of sludge dewatering / Sludge drying, Recycling drying

Water in the sludge thickened in the sludge thickener tank are removed at dehydration process to a certain degree.
However, moisture content is normally more than 80% and the sludge still has adhesiveness and stickiness. Also, latter processes are not easy because of influence of flocculants. Our drying apparatus of KENKI DRYER with international patented technology can surely dry any sticky, adhesive and viscus sludge, and also materials in liquid state like slurry, without clogging inside of the dryer. Also, because of its simple structure, its price is low and apparatus cost of the dryer can be retrieved by reducing industrial waste disposal cost within 3 years. Dried materials can be recycled as fuel, bacterial fertilizer, soil conditioner, etc. since component of the material is hardly changed because of its low-temperature drying method.
It can be applied to a system with pyrolysis apparatus as well.

Sludge drying

Self-cleaning screw

Methods