How the MD Press Works
The MD Press machine are made of stainless steel X5CrNi18-10 (1.4301/SS304). The tungsten carbide screw itself and the plates are made of X2CrNiMo17-12-2 (1.4404/SS316) with special surface treatment technology (tungsten carbide coated).
We are the only manufacturer in the industry using ss316 and surface treatment technology. This ensures abrasion resistance, sufficient hardness and resistance to wear and tear. And of course, this provides the necessary resistance from corrosion from materials which come into contact with aggressive sludge waters.
Sludge-water is carried to the dewatering screw press using a feed pump, which pumps sludge water to the first inlet chamber, where the flow to the other part of the screw press is optimized by means of an overflow. When sludge water leaves the inlet chamber and enters the mixing chamber, a flocculant/polymer is added which makes solid particles aggregate into “flock”.
This process occurs in the mixing chamber while sludge water is slowly mixed with the flocculant by a bladed shaft. The treated sludge water that is flocked flows via an overflow into the screw cylinder, which is the basic mechanism of the press. The variable pitch helix of the screw is completed with plates fulfilling the function of a self-cleaning/moving filter.
Fixed plates form the static structure of the grid whereas the moving plates ensure continuous self-cleaning while the screw is in motion. In terms of structure, there are two fixed and one loose plate on four guiding rods; the loose plate rotates while the screw is in motion. The gap between the fixed and loose plates varies from 0.5 to 0.1 mm.
Water from dewatering flows through this gap. Since the size of the gap continuously changes, the dewatering process is smooth. A pressure piece is mounted at the end of the screw which pushes against the already dewatered sludge, thus increasing the dewatering efficiency. Sludge which is discharged from the end of the machine can be transported, for instance, by means of a belt conveyor.
Dewatering substantially reduces sludge volume, thus reducing transportation and disposal costs.
Sludge-water is a product of the mechanical, biological and chemical treatment of wastewater in wastewater treatment plants. Our dewatering screw press, which serves to thicken sludge water to 15-30% dry-matter content, can provide efficient de-sludging.
In terms of quality, it surpasses traditional sedimentation sludge removal. Our dewatering/thickening screw presses are designed to be used in wastewater treatment plants and can also be used for thickening both industrial water and wastewater in food processing operations. If a dewatering press is already incorporated into a WWTP, design and costs related to the construction of sedimentation tanks are eliminated as this equipment can also be used for thickening secondary sludge directly from activation.
Benefits of this MD Screw Press:
• Low energy use
• Simple installation and operation
• 0.5–5% sludge at inlet and 15–30% sludge at outlet
• Low noise and vibration levels
• Wide use applications
• Automated mode
• Affordable spare parts
• Low transport weight
• Economical operation and a smaller footprint
• High quality workmanship, manufactured in the Czech Republic
These presses can operate in an automatic mode reducing labor costs. The operator can check the status of the equipment and make the necessary adjustments for optimal performance using the PLC touch screen display. The main screw motor is connected to a SEW-EURODRIVE gearbox and thanks to the front transmission achieves 7 rpm. The motor is connected via a frequency inverter, which makes it possible to further accelerate/slow down the screw. These presses can also run in manual mode, where each component can be manually turned on/off by means of the control display.