Schwing Bioset, Incorporated

Charles Michael Wanstrom

Thomas M Anderson

Franz Tillman

Wim H M Moerman

Lakshminarasimha Krishnapura

Shahzad M Khan

Jonathan N Orr

Michael M Mott

A waste treatment process utilizes a two-stage digestion process with a thermophilic digester, a heat exchanger, and a mesophilic digester. The pH of the thermophilic digestate is increased by removal of carbon dioxide with an air stripper, or by adding a pH increasing reagent upstream of the heat exchanger. The pH adjustment of the digestate protects the heat exchanger and downstream equipment and processes from struvite formation. A struvite reactor may be located in various locations downstream of the heat exchanger to produce a treated digestate or effluent that contains struvite, which can optionally be recovered for beneficial use.

Struvite recovery and phosphorus management techniques for wastewater treatment plants

A method of processing biological solids includes blending a sludge with calcium oxide and delivering the blended sludge and calcium oxide to a pressurized container; injecting, into the blended sludge and calcium oxide in the pressurized container, an additive capable of exothermic reactions with the calcium oxide; regulating pH in the pressurized container to produce class A biological solids from the sludge; and pumping the blended sludge, calcium oxide, and additive from the pressurized container to a reactor. A system used for this process include sources of calcium oxide and biological solids, an additive injector, and a pressurized reactor.

Biological solids processing

A sludge flow monitoring system and method measures volume of sludge pumped by a positive displacement pump through a pipeline by determining a fill percentage during each pumping cycle. The start and end of each piston stroke are identified by hydraulic system sensors. The fill percentage is determined based upon a first summation of periodic piston speed command values from the start of a pumping stroke to the end of a pumping stroke, and a second summation of periodic piston speed command values from a poppet valve opening indicating output flow from the pump to the end of the pumping stroke.

Sludge flow measuring system

A drying system includes a fluidized bed dryer and fluidizing gas loop. The system is a closed loop so that fluidizing gas used to dry particulate matter can be reconditioned and recycled to fluidize and dry additional particulate matter. The fluidizing gas is reconditioned by removing fine particulates and water vapor. The drying system includes oxygen control features to prevent oxygen from entering the system. A method for drying particulate matter includes fluidizing the particulate matter in a dryer with a fluidizing gas, heating the particulate matter to remove water, removing water vapor and fluidizing gas from the dryer, removing fines and water vapor from the fluidizing gas, recirculating the fluidizing gas to the dryer to fluidize additional particulate matter and removing dried particulate matter from the dryer. A modular drying system reduces the amount of construction necessary at the installation site.

Closed loop drying system and method

A pump system for pumping a viscous material that includes N positive displacement pumps, where N is an integer greater than two, and a hydraulic drive. Each pump has an inlet and an outlet therefrom, and a pair of cylinders each with a piston movable in a reciprocating stroke cycle therein. The hydraulic drive is connected to the N positive displacement pumps to reciprocate the pistons within the cylinders. The stroke cycle includes a discharging stroke and a filling stroke. The discharging stroke and the filling stroke of the N positive displacement pumps are staggered from one another by 1/N stroke positions such that no two pumps have pistons in the same stroke position at the same time.

Multi-pump sequencing

A method for clearing obstructions in a silo having a reciprocating frame uses an obstruction clearance mode. The method includes driving at least one frame in a reciprocal motion across a silo floor until sensing an indication that at least one frame has encountered an obstruction. Upon sensing the indication of obstruction, an obstruction clearance mode is initiated in an attempt to clear the obstruction.

Growing community of inventors

Maplewood, MN, United States of America

Charles Michael Wanstrom