Optimisation of Dewatering Process
EKOFINN utilizes SCRUDRAIN® Sludge Thickeners for municipal and industrial waste water treatment plants to increase the capacities and achieve better dewatering results with MONOBELT® Belt Filter Presses. The prethickener increases the dry substance content (DS) depending on type of sludge from 1 % up to 5 to 8 Prozent. The SCRUDRAIN® Thickener with Archimedean screw has a very compact design and high capacity.
Design and Function
The main part of the thickener is a rotating drum covered with a filter cloth. Water can pass the filter cloth while sludge and floccs remain inside the drum and are transported to the opposite outlet. The rotating Archimedian screw inside the drum ensures that the sludge is transported to the other end. By changing the speed of rotation the retention time of the sludge can be adjusted. The screw prevents short circuit flow inside the drum. Due to this design the thickener can achieve high dewatering results.
The filter cloth is continuously washed from outside, while solids remain inside the drum. In this way the filtrate remains clear and has such a quality that in most cases it can be used for washing.
By using a special way of fixing the cloth to the drum frame the cloth is not under tension and has a long life. The SCRUDRAIN® Thickeners can depending on the type of sludge and DS-content be used for applications with few m3/h to 60 m3/h. By changing the rotation speed of the filter drum and therefore also the retention time of the sludge the concentration of the discharge can be manually adjusted while also adjusting the consumption of polyelectrolyte.
In general the DS-content of the inlet sludge can be from 0.5 to 3 % while the outlet thickened sludge may range from 5 to 13 %. EKOFINN also supplies suitable polymer preparation units of the series CAP-CE and CAP-EM.