Agway Inc.

Other

Norwood K Talbert

A fertilizer product consisting of solid, substantially dry, spherical or semi-spherical granules of ammonium sulfate and sewage sludge solids is formed by adding to a quantity of crystalline ammonium sulfate in a mixing vessel a second quantity of water-laden sludge while mixing the two together and driving off water from the sludge until granulation is complete. The sludge is added slowly enough, relative to the rate at which water is removed therefrom, that the ammonium sulfate crystals do not dissolve in the water initially contained in the sludge. Sludge solids effectively fill the voids between individual ammonium sulfate crystals in the resulting granules, thereby producing an end product of improved size and shape.

Method of producing fertilizer product containing sewage sludge

A process for dewatering sewage sludge having a water content on the order of 75% to 95% and previously untreated for the release of such water. The sludge is mixed with a chemical selected from the group consisting of urea and the common ammonium and potassium salts in relative quantities which produce a desired degree of phase separation. The hygroscopic qualities of the chemical operate to remove water from the sludge to form a separate liquid phase of the chemical dissolved in water removed from the sludge, and a solid or semi-solid phase of the sludge solids with any remaining water. The phases may then easily be separated with great simplification of subsequent handling, disposal or further processing of each.

Process for dewatering sewage sludge

Sludge from a municipal or industrial sewage treatment facility is mixed with a mineral acid or anhydride thereof to release the entrapped water in the sludge. The remaining mixture of sludge solids and diluted acid or anhydride is then mixed with a basic material, such as ammonia, the heat generated by reaction of the base and acid evaporates the water to form either a completely dry mixture of sludge solids and a salt, or a mixture having a predetermined moisture content which may be air dried. In some applications it is preferable to recycle a portion of the end product by adding it to the reaction vessel.

Process of dewatering sewage sludge

A method of prilling material in a prilling tower having the usual means for discharging molten material at the upper end thereof in droplet form to fall freely downwardly therein whereby the droplets cool and solidify in spherical or spheroidal form. A manifold extends about the interior of the upper portion of the tower and directs a continuous spray of water against the interior wall of the tower to provide a falling film of water along such wall substantially entirely about the interior circumference of the prilling chamber to cool the chamber and thus hasten solidification of the material and also prevent deposit of the material on the tower wall. Relatively fine unprilled particles of material which drift outside of the prilling zone and reach the wall of the tower are entrained with the water which is collected separately from the prills at the bottom of the tower and conducted away from the tower where the entrained material may be recovered and the water may be conducted back to the manifold for reuse or discharged.

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Manlius, NY, United States of America

Norwood K Talbert