# US 8,464,437 B1 · Apparatus and method for the treatment of biosolids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,437 B1 - Document ID: US8464437B1 - Status: Granted - Kind: B1 - Application number: 13/480,732 - Filed: 2012-05-25 - Granted: 2013-06-18 - Earliest claimed: 2012-05-25 - Assignees: Wyssmont Company Inc. - Applicants: Edward Weisselberg - Inventors: Edward Weisselberg - Web page: https://patentgrep.com/patent/US8464437B1 ## CPC - C02F 11/18: by thermal conditioning (by pyrolysis C02F11/10) - C02F 11/13: by heating - F26B 17/003: {with fixed floors provided with scrapers (F26B17/006 and F26B17/007 take precedence)} - F26B 2200/18: Sludges, e.g. sewage, waste, industrial processes, cooling towers - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - F26B: DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM (drying devices for combines A01D41/133; racks for drying fruit or vegetables A01F25/12; drying foodstuffs A23; drying hair A45D20/00; body-drying implements A47K10/00; drying household articles A47L; drying gases or vapours B01D; chemical or physical processes for dewatering or like separating liquids from solids B01D43/00; centrifugal apparatus B04; drying ceramics C04B33/30; drying yarns or fabrics in association with some other form of treatment D06C; drying frames for laundry without heating or positive air circulation, domestic laundry-or spin-driers, wringing or hot pressing laundry D06F; furnaces, kilns, ovens F27) ## Abstract Biosolids in the nature of sewage sludge is processed in a controlled environment to produce a dried sludge product of relatively high dry solid content with the elimination of or reduced levels of pathogens. The water containing sewage sludge is dried while cascading within a processing chamber using heated air at a temperature below the ignition or smoldering temperature of the sewage sludge to prevent the formation of embers. The sewage sludge before discharge is retained within the processing chamber for a sufficient time and temperature as mandated by the Environment Protection Agency rules and guidelines. ## Claims ### Claim 1 A method for treatment of sewage sludge containing a pathogen, comprising: cascading sewage sludge containing water and at least one pathogen between a plurality of supports vertically stacked within an upper portion and a lower portion of a processing chamber; heating the sewage sludge while cascading between the supports within the upper portion of the processing chamber to remove a portion of the water within the sewage sludge thereby forming a reduced water content sewage sludge; heating the reduced water content sewage sludge within the lower portion of the processing chamber for a sufficient time and at a sufficient temperature to reduce the amount of the at least one pathogen thereby forming a treated sewage sludge; exiting exhaust gas created in the upper and lower portions of the processing chamber; recycling at least a portion of the exhaust gas to the processing chamber for heating the sewage sludge contained therein; supplying heated gas to the upper portion of the processing chamber for removing a portion of the water contained within the sewage sludge and to the lower portion of the processing chamber for reducing the amount of the at least one pathogen within the sewage sludge; and controlling the temperature of the heated gas within the processing chamber below the ignition temperature of the sewage sludge to prevent the formation of embers therefrom. ### Claim 2 (depends on 1) The method of claim 1, wherein the treated sewage sludge has a dry solid content of at least 90% by weight. ### Claim 3 (depends on 1) The method of claim 1, wherein heating the sewage sludge for a sufficient time and at a sufficient temperature to reduce the amount of the at least one pathogen comprises heating the sewage sludge of reduced water content to a temperature in the range of 50° C.-80° C. or higher for a time in the range of 20-30 minutes or longer. ### Claim 4 (depends on 1) The method of claim 1, wherein the temperature comprises 80° C. and the time comprises at least 30 minutes. ### Claim 5 (depends on 1) The method of claim 1, wherein the heated gas supplied to the processing chamber is in the range of 150° C.-175° C. ### Claim 6 (depends on 5) The method of claim 5, wherein the heated air within the processing chamber is controlled within the range of 120° C.-150° C. ### Claim 7 (depends on 1) The method of claim 1, wherein supplying the heated gas to the processing chamber further comprises discharging the gas into the processing chamber in a direction perpendicular to a diameter of a housing providing the processing chamber. ### Claim 8 (depends on 1) The method of claim 1, further including rotating the supports while the sewage sludge cascades within the processing chamber.