The drainagealso known as dewatering is a central step in the sludge drying sludge drying. The term refers to the process of water removal from sludge produced by various industrial, municipal and agricultural processes. The aim is to reduce the volume of the recyclable material and to prepare it for disposal disposal or later recycling.
What is the aim of dewatering in sludge drying?
The aim of dewatering sewage sludge, metal sludge, biosludge and other sludges is to reduce the water content of the sludge down to 10-30%. In this way, it is possible to reduce the volume and weight of the sludge, which generally had a high water content beforehand, many times over.
This process step greatly simplifies transportation, logistics and further processing, as well as possible final storage of the sludge. Dewatering therefore plays a decisive role in sludge drying, as it increases the dry mass and makes the subsequent drying processes energetically more efficient.
Typical methods of dewatering include mechanical processes such as centrifugingfilter pressing or the use of belt filters, which effectively extract water from the sludge without damaging the solids.
How does dewatering work in sludge drying plants?
The dewatering is an indispensable part of sludge disposal, as it forms the basis for all further processing steps. Dewatering comprises the following steps:
- Addition of flocculants: Improving separation efficiency by agglomerating fine particles
- Mechanical separation: Use of devices such as centrifuges, hydrocyclones and filter presses that separate water from sludge using pressure and rotational forces
- Water discharge: Collection and filtration of separated water to meet all environmental requirements
- Checking the consistency: Checking the sludge consistency after dewatering to ensure quality for subsequent processes
After these steps, the dewatered sludge can be used directly, dried further or used as a starting material for the manufacture of products such as fertilizers or fuels.