A biomass burner and a method of burning biomass in the form of solid particulate fuel

Abstract

A biomass burner comprising a primary oxygen feed 13 and gas distributor 15 configured to fluidize solid particulate fuel 17 within a primary combustion zone 11. The primary combustion zone 11 is loca

Claims

1. A biomass burner for burning a solid particulate fuel, the biomass burner comprising:a fuel feed channel configured to convey a solid particulate fuel to a primary combustion zone;a primary oxygen feed configured to convey oxygen to the primary combustion zone;a gas distributor connected to the primary oxygen feed, the gas distributor configured to fluidize the solid particulate fuel within the primary combustion zone;wherein the fuel feed channel is located adjacent to the primary combustion zone such that, in use, solid particulate fuel therein is heated by combustion within the primary combustion zone, resulting in gasification of the solid particulate fuel within the feed channel to produce combustible gas, prior to introduction into the primary combustion zone;a duct configured to convey the combustible gas from the fuel feed channel to a secondary combustion zone; anda secondary oxygen feed configured to convey oxygen to the secondary combustion zone, so as to combust the combustible gas.

2. The biomass burner of claim 1, wherein the primary combustion zone surrounds a radial periphery of the fuel feed channel.

3. The biomass burner of claim 1 or claim 2, wherein the fuel feed channel is configured to be under-stoked such that solid particulate fuel supplied to a lower (first) end thereof causes solid particulate fuel within the fuel feed channel to be expelled from an upper (second) end thereof, opposing the lower (first) end.

4. The biomass burner of any preceding claim, further comprising paddles within the fuel feed channel for stirring the solid particular fuel.

5. The biomass burner of any preceding claim, further comprising a rotating arm located adjacent to the upper periphery, and configured to rotate about a central shaft.

6. The biomass burner of any preceding claim, further comprising at least one horizontal screw conveyer arranged to supply the solid particulate fuel to a lower end of the fuel feed channel.

7. The biomass burner of any preceding claim, further comprising a gas distributormay comprise a distributor plate configured such that, with a predefined flow-rate of gas conveyed from the primary oxygen feed through the distributor plate from below, the solid particulate fuel within the primary combustion zone is fluidized.

8. The biomass burner of any preceding claim, further comprising an ignition deviceconfigured to ignite combustion of the solid particulate fuel within the primary combustion zone.

9. The biomass burner of any preceding claim, further comprising a flue configured to convey hot gas away from the primary combustion zone, and wherein the duct may comprise the flue.

10. The biomass burner of any preceding claim, wherein the secondary oxygen feed is configured to pass around the flue such that the oxygen is pre-heated before reaching the secondary combustion zone.

11. A food waste processing system, comprising:an aerobic digester configured to convert food waste into solid particulate fuel; andthe biomass burner according to any preceding claim, further configured to receive the solid particulate fuel from the aerobic digester.

12. A generator system, comprising:the biomass burner according to any one of claims 1 to 10; anda heat converter configured to convert heat produced by the biomass burner into usable energy.

13. An energy-from-food waste system, comprising:an aerobic digester configured to convert food waste into solid particulate fuel;the biomass burner according to any one of claims 1 to 10, further configured to receive the solid particulate fuel from the aerobic digester; anda heat converter configured to convert heat produced by the biomass burner into usable energy.

14. A method of burning biomass in the form of solid particulate fuel, the method comprising the steps of:providing a biomass burner according to any one of claims 1 to 10;conveying a solid particulate fuel through the fuel feed channel to the primary combustion zone;conveying oxygen through the primary oxygen feed to the primary combustion zone;fluidizing the solid particulate fuel within the primary combustion zone by passing oxygen through the gas distributor from the primary oxygen feed;combusting solid particulate fuel within the primary combustion zone;heating solid particulate fuel within the fuel feed channel with heat from said combusting within the primary combustion zone, resulting in gasification of the heated solid particulate fuel within the fuel feed channel to produce combustible gas, prior to introduction into the primary combustion zone;conveying the combustible gas through the duct from the fuel feed channel to the secondary combustion zone; andconveying oxygen through the secondary oxygen feed to the secondary combustion zone, so as to combust the combustible gas.

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