Independent pre-thickening with rotary drum thickener (RDT): Enhanced capacity and cake solids. Independently controlled pre-thickening and dewatering pressure section allows significantly greater process optimization than possible when the two sections are coupled. Pre-thickening is accomplished by an Independent RDT. Because the RDT is a totally separate unit the size can be easily changed to provide the pre-thickeing filtration area required for the application.
Slot screen design: Prevents plugging, maximizes capacity. Perforated plate or wedge wire limits the porosity of the filter surface to 1 mm diameter due to structural issues. The DSP Screw Press uses a unique in-house fabricated water jet slotted screen design to allowing maximin drainage. The slotted arrangement /configuration and special wedge cross section profile of each slot prevents solids loss with the filtrate while allowing for maximum drainage by not plugging or blinding.
Filtrate recycle: Significantly improves solids capture. Filtrate from the end of the high pressure screw section is recycled back to the Rotary Drum Thickener section, thereby capturing solids that would normally be lost with the pressure section filtrate.
Replaceable flight: Lowers maintenance costs. Competitors typically incorporate screw flights welded to the shaft. BDP’s design has flights that are bolted to a base assembly allowing the flights to be adjusted and easily replaced, thereby maintaining proper clearance between the flight tip and the slotted screen. This ensures optimum performance as it reduces thickness of the material that accumulates on the internal screen surface thereby maximizing filtrate drainage.
Tapered screw design: Highest cake solids in the industry. A screw press functions by reducing the volume inside the perforated enclosure as the screw augers the cake toward the discharge. BDP Industries uses a tapered auger shaft. This creates a reduction in path length for the liquid to be expressed from the cake and causes a pressure force at right angle to the auger shaft and against the perforated drum. This reduces the tendency for plug formation and means higher pressures are possible or drier cake. Most manufacturers reduce the distance between screw flights toward the discharge end. This method means that the path length for the liquid to be expressed from the cake stays constant and the pressure exerted on the cake is primarily along the axis of the screw flights. This axial pressure against the face of the screw flights increases the potential to cause the cake to turn with the screw. When this happens the cake is no longer being augered, causing what is referred to as plug formation.
Pressure Plate: Easy adjustment ensures desired cake solids. An adjustable pressure plate at the discharge of the screw allows maximization of the cake solids. The pressure plate utilizes three adjustment nuts to vary the pressure. This easyto- operate design allows for simple pressure setting.