Bio Gro Systems, Incorporated

Other

Mark J Girovich

Donald P Clark

Jerome F Dausman

Michael A Pace

An alkaline stabilization process for treating partially dewatered sludge while reducing lime consumption, increasing nutrient values and applicability of the product, and enhancing physical handling characteristics such as dryness, granularity and spreadability including feeding a predetermined amount of partially dewatered sludge to a first mixer, adding a predetermined amount of alkaline material to the sludge in the first mixer, mixing the sludge and alkaline material together in the first mixer to form a mixture, discharging the mixture from the first mixer, directing the mixture to a second mixer, adding a predetermined amount of end product enhancing additive to the second mixer, mixing the mixture and end product enhancing additive in the second mixer to form an end product and discharging the end product from the second mixer. The system for carrying out the process includes a first mixer, a first feeder for feeding a predetermined amount of partially dewatered sludge to the first mixer, a holding bin to retain the mixture, a second feeder for feeding a predetermined amount of alkaline material to the first mixer in sufficient quantity to heat a mixture of sludge and alkaline material to a predetermined temperature and raising the pH level of the mixture to a predetermined level, a transferring device for transferring the mixture from the first mixer, a second mixer for receiving the mixture from said transferring device, a third feeder for feeding a predetermined amount of an end product enhancing additive to the second mixer and a discharge conveyor for discharging a beneficial use end product from the second mixer.

Method for alkaline treatment of sewage sludge for beneficial use

A process for the production of a durable granular or pelletized sludge product is disclosed whereby a minimal amount of high calcium oxide material is utilized for pathogenic stabilization, a portion of the resulting hot mixture being recycled back to the mixing stage to reduce the requisite lime consumption by utilizing unreacted lime, for energy recovery and to increase dryness.

Method for the treatment of sewage sludge and the like

A stackable combination party tray for food, drink, utensils and napkins has a flat rectangular platform with two or more recessed food compartments, surrounded by an upturned peripheral retaining lip, one recessed compartment for holding a plurality of sizes of beverage containers, one recessed compartment for holding utensils and one recessed compartment for holding a napkin. These three compartments are each of the same depth and have flat bottom surfaces to provide three points of support for permitting the tray to be supported on a support surface. The beverage container compartment extends a distance below the bottom surface of the rectangular platform a distance sufficient to allow a person's hand to grip the tray. Thus, one's tray and drink can be held in one hand.

Combination food, drink, utensil and napkin tray

A process for the production of a durable granular or pelletized sludge product is disclosed whereby a minimal amount of high calcium oxide material is utilized for pathogenic stabilization, the resulting material being further processed through an agglomeration stage. A portion of the agglomerated material is further processed in a moisture reduction or drying stage and recycled back to the agglomeration stage for percent solids adjustment and promotion of agglomeration. An apparatus for performing the process is also disclosed.

Method and apparatus for the treatment of sewage sludge and the like

Dewatered municipal sludge is dried and simultaneously pelletized in an indirect dryer. A sweep air is introduced into the dryer to extract a water vapor and air mixture. The water vapor and air mixture is condensed and cleaned in a condensor and a scrubber to obtain a clean non-condensable gas. The non-condensable gas is heated and recycled to the dryer after heating for use as the sweep air. Since air leakage into the system is inevitable, an excess amount of air accumulates that does not need to be recycled to the dryer. The excess amount of air is diverted from the recycled sweep air and thermally treated to destroy any malodorous gaseous constituents contained therein. Preferably, the indirect dryer is a horizontal drum dryer that is heated by the hot flue gases from a combustion furnace. The condenser for condensing the water vapor and sweep air mixture extracted from the dryer is cooled by the liquid sludge entering the dewatering treatment phase of the process, and the waste flue gas from the furnace is used to heat the recycled sweep air in order to save energy by recovering waste heat of the system.

Process of drying and pelletizing sludge in indirect dryer having

Municipal sludge is dried in an indirect heating dryer to simultaneously dry and pelletize the sludge while preventing the escape of malodorous gases. The product exiting the dryer contains pelletized, undersized and oversized fractions. The dried product is classified to separate the undersized and oversized fractions from the pellets. The pellets are then cooled and stored for subsequent use as a fertilizer or fuel. The oversized fraction is crushed to obtain fines and mixed with the undersized fraction, which contains mostly fines. The fines are added to the liquid sludge before it is input to the dryer. The air that is used to cool the pellets, and that is used as sweep air in the dryer contains malodorous gases. In order to prevent the escape of these malodorous gases, the pellet cooling air and sweep air, which also includes the water vapor generated during the drying of the sludge, is deodorized by thermal treatment, preferably in a high temperature combustion zone.

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Baltimore, MD, United States of America

Mark J Girovich