Method and a system for drying sludge
Patent 5373647 Issued on December 20, 1994. Estimated Expiration Date: 
February 8, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 8, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2439384 Two-stage mechanical dewatering of sewage sludge Method and apparatus for drying sludge Method and device for removing liquid from a mixture of solids and liquids Patent #: 4962592 InventorsAssigneeApplicationNo. 958354 filed on 02/08/1992US Classes:34/382, Material shaping34/60, For diverse operations on treated material34/182, Axial treated material feed type34/183, Axial treated material feed type34/385, Material shaping34/420, Including radiation or convection treatment34/449Condensation of gas or vaporExaminersPrimary: Gromada, Denise L.Attorney, Agent or FirmForeign Patent References
International ClassesF26B 007/00618 619 623 Foreign Application Priority Data1990-06-28 DKAbstractA method and a system serve to completely or partially dehydrate sludge by evaporation which originates from e.g. sewage. The sludge is dried with addition of heat in a drying chamber (2), the sludge being transported on an endless travelling grate (3) from an inlet opening (8) in the drying chamber (2) to a discharge opening (9) in it. The sludge is deposited on the grate in a plurality of juxtaposed sludge strings (18) by means of an extruder (6), in which the sludge is preheated to almost 100° C. prior to extrusion. The extruded strings (18) are then heated with such an intensity that the water in the sludge immediately begins to boil, and that a zone of preferably saturated water steam is formed at any rate in the immediate vicinity of the sludge. This provides a light and porous, dried sludge product which is in no way either burnt or scorched, and which constitutes excellent fuel as well as excellent compost. The system has a simple and compact construction and is inexpensive to produce, just as it works at moderate operation costs.Field of SearchStationary receptacle or tube with agitator or conveyorPlural units With gas or vapor flow for contact with treated material Axial treated material feed type Axial treated material feed type Rotary or swinging carrier or rack For diverse operations on treated material With two or more nondrying means With nondrying treating of material Nondrying treating precedes drying Material shaping Material shaping Sheet, web, or strand Including radiation or convection treatment Running length Gas or vapor contact with treated material Sheet, web, or strand Condensation of gas or vapor Condensation of gas or vapor Diverse heater types and/or gas or vapor contact types only By vapor condensation | |
