Multi-functional fecal waste and garbage processor and associated methods

• US 9,708,937 B2
• Filed: 11/14/2014
• Issued: 07/18/2017
• Est. Priority Date: 11/14/2014
• Status: Active Grant

• Current Assignee: Bill & Melinda Gates Foundation
• Original Assignee: Bill & Melinda Gates Foundation
• Inventors: Janicki, Peter
• Primary Examiner(s): NGUYEN, HOANG M
• Application Number:
  US14/542,521
• Publication Number:
  US 20160138433A1
• Time in Patent Office: 977 Days
• Field of Search: 60670, 34 72, 34 73, 34 86, 34210, 34407
• CPC Class Codes: B01D 1/04 Evaporators with horizontal tubes
• CPC Class Codes: B01D 1/226 in the form of a screw or with helical blade members
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/004 using large scale industrial sized filters
• CPC Class Codes: C02F 1/04 by distillation or evaporation
• CPC Class Codes: C02F 1/20 by degassing, i.e. liberation of dissolved gases degasification of liquids in general B01D19/00; arrangement of degassing apparatus in boiler feed supply F22D
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 11/06 by oxidation incinerators for burning waste liquors, e.g. sulfite liquor from paper-making plant F23G7/04
• CPC Class Codes: C02F 11/12 by de-watering, drying or thickening
• CPC Class Codes: C02F 11/13 by heating
• CPC Class Codes: C02F 2303/06 Sludge reduction, e.g. by lysis
• CPC Class Codes: C02F 2303/10 Energy recovery
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage
• CPC Class Codes: F01K 17/04 for specific purposes other than heating F01K17/06 takes precedence
• CPC Class Codes: F01K 17/06 Returning energy of steam, in exchanged form, to process, e.g. use of exhaust steam for drying solid fuel or plant
• CPC Class Codes: F01K 25/04 the fluid being in different phases, e.g. foamed
• CPC Class Codes: F22B 31/0007 with combustion in a fluidized bed fluidized bed apparatus per se B01J8/00; fluidized bed combustors F23C10/00
• CPC Class Codes: F23G 5/04 drying
• CPC Class Codes: F23G 5/30 having a fluidised bed
• CPC Class Codes: F23G 5/40 : Portable or mobile incinerators
• CPC Class Codes: F23K 1/04 : Heating fuel prior to delivery to combustion apparatus
• CPC Class Codes: F23K 2201/20 : Drying
• CPC Class Codes: Y02E 20/12 : Heat utilisation in combustion or incineration of waste
• CPC Class Codes: Y02E 50/10 : Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 : Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02W 10/30 : Wastewater or sewage treatment systems using renewable energies
• CPC Class Codes: Y02W 10/40 : Valorisation of by-products of wastewater, sewage or sludge processing

Abstract

At least one aspect of the technology provides a self-contained processing facility configured to convert organic, high water-content waste, such as fecal sludge and garbage, into electricity while also generating and collecting potable water.

Claims

1. A multifunctional waste processing system for electricity and water generation, comprising:

a fuel dryer assembly having a fuel path with a fuel inlet configured to receive a flow of wet organic-based sludge comprising a mixture of water and solid fuel material, the fuel dryer assembly having a heater portion configured to boil the sludge and thermally separate water from the solid fuel material to provide dried fuel, the fuel dryer having a first steam outlet, a dry fuel outlet, and a condenser portion having fluid path with a steam inlet and a fluid outlet, the fluid path being isolated from the fuel path;

a fresh water condenser assembly coupled to the first steam outlet and configured to condense water vaporized from the sludge into clean liquid water;

a dry fuel combustor assembly coupled to the dry fuel outlet of the fuel dryer assembly, the dry fuel combustor assembly having a combustor portion and having a boiler configured to receive heat from the combustor portion, the boiler having a first water inlet and a second steam outlet;

a steam-powered generator coupled to the second steam outlet of the boiler and configured to generate electricity, the steam-powered generator having a third steam outlet coupled to the steam inlet of the condenser portion; and

a water pump having a second water inlet coupled to the fluid outlet of the condenser portion of the fuel dryer; and

the water pump having a water outlet coupled to the first water inlet of the boiler;

wherein the boiler is configured to convert a flow of water entering the boiler to a flow of steam to power the steam-powered generator.

2. The system of claim 1 wherein the fuel dryer assembly comprises a steam-heated auger in the fuel carrier and configured to move and heat the sludge during the drying process.

3. The system of claim 1 wherein the fuel dryer assembly is a multi-segment dryer having sequential first and second dryer segments each coupled to the condenser portion and each configured to dry the sludge by vaporizing water from the sludge using heat from exhaust steam from the steam-powered generator.

4. The system of claim 3 wherein the first dryer segment generates sludge steam from the sludge, and the second dryer segment uses the sludge steam from the first segment to dry the sludge.

5. The system of claim 3 wherein the first dryer segment generates first dryer steam from water vaporized from the sludge, and the second dryer segment has a first steam carrier portion coupled to the first dryer segment and configured to carry the first dryer steam adjacent to the fecal sludge, and the second dryer segment having a second steam carrier portion isolated from the first steam carrier portion and configured to carry the exhaust steam from the steam-powered generator adjacent to the sludge, wherein heat from the first and second steam carrier portions dries the sludge moving therein.

6. The system of claim 1 wherein the fuel dryer assembly is configured to receive in the condenser portion exhaust steam from the steam-powered generator, the fuel dryer having a first dryer segment connected to the fuel inlet and has a first heater portion coupled to the condenser and configured to vaporize a first portion of the water from the sludge with heat from the exhaust steam, and a second dryer segment connected in series to the first dryer segment and configured to vaporize a second portion of the water from thickened sludge received from the first dryer segment with heat from the exhaust steam.

7. The system of claim 1 wherein the condenser portion of the fuel dryer assembly is configured to receive exhaust steam from the steam powered generator through the first steam inlet, and the fuel dryer assembly having a dryer portion connected to the fuel inlet and adjacent to the condenser portion, the dryer portion is configured to vaporize water from the sludge using the heat from the exhaust steam in the condenser.

8. The system of claim 1 wherein the combustor portion is a fluidized bed combustor assembly.

9. The system of claim 1 wherein the fuel dryer assembly, the fresh water condenser, the dry fuel combustor assembly, the steam powered generator, and the water pump are mounted on a frame and transportable with the frame as a unit.

10. The system of claim 1 wherein the steam-powered generator is a single action, liquid cooled steam engine.

26. The system of claim 1, further comprising a water filtration system coupled to the freshwater condenser assembly and configured to receive the clean water, the water filtration system having one or more filters that filters the clean water and provides potable water.

27. The system of claim 1, wherein the fluid inlet of the fluid dryer assembly is configured to receive a flow of fecal sludge.

28. The system of claim 1, wherein the sludge dryer assembly comprises a rotatable, hollow auger in the heater portion and configured to receive steam exhausted from the steam engine to heat the auger, wherein the auger is configured to move and heat the sludge during the drying process.

11. A sludge processing system for electricity and clean water generation, comprising:

a sludge dryer assembly having a fuel path with a sludge inlet configured to receive a flow of sludge comprising a mixture of water and solid fuel material, the sludge dryer assembly having a heater portion configured to heat the sludge and thermally separate water from the solid fuel material to provide dried fuel material, the heater portion having a first steam outlet, the sludge dryer assembly having a condenser portion adjacent to the heater portion and having fluid path isolated from the fuel path and having a steam inlet and a fluid outlet;

a fresh water condenser assembly coupled to the first steam outlet and configured to condense water evaporated from the sludge into clean liquid water;

a combustor assembly coupled to the sludge dryer assembly and configured to receive the dried fuel material therefrom, the combustor assembly having a combustor configured to receive and burn the dried fuel material, and having a boiler configured to receive heat from the combustor for creating steam in a fluid path extending between a water inlet and a second steam outlet; and

a power plant comprising a steam engine and a generator driven by the steam engine, the steam engine being coupled to the second steam outlet of the boiler to receive steam therefrom, and the generator being configured to generate electricity, the steam powered generator having a third steam outlet coupled to the steam inlet of the condenser portion;

wherein heat from the steam exhausted from the steam engine boils the water in the sludge in the sludge dryer;

wherein the steam exhausted from the steam engine is condensed to a flow of liquid water; and

wherein the boiler is configured to receive and convert the flow of liquid water to a flow of steam to power the generator.

12. The system of claim 11 wherein the heater portion of the sludge dryer assembly comprises a sludge carrier portion through which the sludge moves, a steam carrier adjacent to the sludge carrier and positioned adjacent to the sludge for delivery of heat from steam in the steam carrier to the sludge, and a plurality of propulsion members moveably disposed within the fuel carrier and configured to move the sludge in the fuel carrier relative to the steam carrier.

13. The system of claim 11 wherein the fuel dryer assembly is a two-stage dryer having sequential first and second dryer stages each coupled to the condenser portion and each configured to dry the sludge by boiling the water in the sludge to provide dried solid fuel material using heat from exhaust steam from the steam engine.

14. The system of claim 11 wherein the fuel dryer assembly is a two-stage dryer having sequential first and second dryer stages, wherein the first dryer stage generates sludge steam from the sludge, and the second dryer stage uses the sludge steam from the first dryer stage to dry the sludge.

15. The system of claim 11 wherein the fuel dryer assembly is a multi-segment dryer having sequential first and second dryer segments, the first dryer segment generates first dryer steam from water vaporized from the sludge, and the second dryer segment has a first steam carrier portion coupled to the first dryer segment and configured to carry the first dryer steam adjacent to the sludge, and the second dryer segment having a second steam carrier portion isolated from the first steam carrier portion and configured to carry the exhaust steam from the steam engine adjacent to the sludge, wherein heat from the first and second steam carrier portions dries the sludge moving therein.

16. The system of claim 15 wherein the first dryer segment comprises a first fuel carrier, a first steam carrier adjacent to the first fuel carrier, a plurality of propulsion members moveably disposed within the first fuel carrier and configured to move the sludge through the first fuel carrier past the first steam carrier;

and the second dryer segment comprises a second fuel carrier, a plurality of steam-heated members within the second fuel carrier and being stationary relative to the second fuel carrier, and a second steam carrier assembly rotatably disposed within the second fuel carrier and configured to move the sludge within the second fuel carrier and past the steam-heated members.

17. The system of claim 11 wherein the condenser portion of the sludge dryer assembly is positioned to receive exhaust steam from the steam engine, the sludge dryer assembly has a first dryer stage with a first heater portion coupled to the condenser portion and configured to vaporize a first portion of the water from the sludge with heat from the exhaust steam, and a second dryer stage connected to the first dryer stage and configured to vaporize a second portion of the water from thickened wet sludge received from the first dryer stage with heat from the exhaust steam.

18. The system of claim 11 wherein the condenser portion is configured to receive exhaust steam from the steam powered generator, and the fuel dryer assembly has a dryer portion adjacent to the condenser portion and configured to vaporize water from the sludge using the heat from the exhaust steam in the condenser.

19. The system of claim 11 wherein the combustor portion is a fluidized bed combustor assembly with a firebox having a combustor bed for dry fuel combustion and an air grate configured to provide combustion air to the combustor bed, and the boiler comprising first heat exchanger connected to the water inlet and configured to heat water flowing therethrough, a steam drum coupled to the first heat exchanger, an evaporator coupled to the steam drum and configured to receive heated, saturated fluid therefrom, the steam drum being configured to receive a flow of steam from the evaporator, and a second heat exchanger coupled to the steam drum and configured to receive dry steam from the steam drum, the second heat exchanger connected to the second steam outlet.

20. The system of claim 11, further comprising:

a sludge containment tank; and

a sludge transporter connected to the sludge containment tank and configured to provide the sludge to the sludge inlet of the sludge dryer assembly.

21. The system of claim 20, wherein the sludge containment tank is a fecal sludge containment tank, and the sludge transporter is configured to provide fecal sludge to the sludge inlet of the sludge dryer assembly.

22. The system of claim 11, further comprising a water filtration system coupled to the freshwater condenser assembly and configured to receive the clean water, the water filtration system having one or more filters that filters the clean water and provides potable water.

23. The system of claim 11, wherein the sludge inlet of the sludge dryer assembly is configured to receive a flow of organic-based sludge.

24. The system of claim 11 wherein the fuel dryer assembly comprises a steam-heated auger in the heater portion, the steam-heated auger being configured to move and heat the sludge during the drying process.

25. The system of claim 11, wherein the sludge dryer assembly comprises a rotatable, hollow auger in the heater portion and configured to receive steam exhausted from the steam engine to heat the auger, wherein the auger is configured to move and heat the sludge during the drying process.