GB2551106B

GB2551106B - Solid fuel burner

Info

Publication number: GB2551106B
Application number: GB1607275.3A
Authority: GB
Inventors: Elliott Brian; Elliott Gregory
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-04-26
Filing date: 2016-04-26
Publication date: 2019-07-31
Anticipated expiration: 2036-04-26
Also published as: GB2551106A

Description

Solid Fuel Burner

The present invention relates to a solid fuel burner which uses solid fuels and more specifically to biomass burners.

Conventional heating systems that utilise a solid fuel such as biomass are generally formed of two main components - the first component being the heating component such as but not limited to water boilers/heaters, outdoor patio heaters, space heaters for both domestic and commercial use, barbecue grills, ovens and cookers for both domestic and commercial use and the second component being the burner component. The burner component performs the combustion of the fuel in order to provide the required heat for heat emanation from the heating component. The burner can be either automatically operated by a control system or manually operated by an operator.

In typical burner systems fuel is fed into combustion chambers whether automatically or manually operated from the devices external to the combustion chamber by the use of a hopper loaded with fuel for example. This presents problems more generally with regards to manually operated burner units. For manually operable burner units an operator must predetermine the amount of pellets for combustion to heat the boiler or other such heating component over a certain fixed time as the combustion chamber is continually replenished with fresh fuel from the hopper. Should an operator add too little of an amount of solid fuel to the hopper insufficient heat will be generated and more fuel will be required to be added at a later stage. The worst case scenario is that all of the fuel is already combusted during a time of heat demand. Likewise if too much fuel is added to the hopper, the boiler or the like will produce inefficient heat spikes and/or will heat for a longer period of time than would be necessary. Conventional manual burners continue to burn until the fuel supply has combusted. As a result, this produces an inefficient use of energy and can be a costly exercise for an operator over time.

It is an object of the present invention to obviate or mitigate the problem of energy efficiency in conventional manually operable burner units for heating systems.

Accordingly, the present invention provides a burner for solid fuel comprising: at least one combustion chamber, a means for delivering solid fuel to the at least one combustion chamber and means for adjusting the volume of the combustion chamber wherein the means for adjusting the volume of the combustion chamber is moveably displaceable to adjust the width of the at least one combustion chamber.

Preferably, the means for adjusting the volume of the at least one combustion chamber is a manual adjustment means.

Preferably, the means for adjusting the volume of the combustion chamber is moveably displaceable to adjust the surface area of a floor of the at least one combustion chamber.

Ideally, the means for adjusting the volume of the combustion chamber is moveably displaceable traverse to the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the means for adjusting the volume of the combustion chamber is moveably displaceable traverse to a direction of flow of the fuel.

Ideally, the means for adjusting the volume of the combustion chamber is moveably displaceable perpendicular to a direction of flow of the fuel.

Preferably, the means for adjusting the volume of the combustion chamber is moveably displaceable in a direction parallel to a floor of the combustion chamber.

Advantageously, the ability to adjust the volume of the combustion chamber allows an operator to adjust the heat output of the solid fuel burner in a simple and efficient way conserving energy and costs to the operator.

Ideally, the volume of the combustion chamber can be adjusted prior to solid fuel combustion, during combustion and after combustion.

Preferably, the at least one combustion chamber is at least partly formed by a grate.

Ideally, the grate of the at least one combustion chamber is capable of retaining the solid fuel within the at least one combustion chamber for at least partial combustion of the solid fuel.

Ideally, the means for adjusting the volume of the combustion chamber is at least partly formed by a grate.

Ideally, the grate of the means for adjusting the volume of the combustion chamber is capable of retaining the solid fuel within the at least one combustion chamber for at least partial combustion of the solid fuel.

Preferably, the at least one combustion chamber comprises guide means to guide the movement of the means for adjusting the volume of the combustion chamber into and out of the combustion chamber.

Preferably, the means for adjusting the volume of the combustion chamber is slidably displaceable traverse to a direction of flow of the fuel.

Ideally, the means for adjusting the volume of the combustion chamber is slidably displaceable perpendicular to a direction of flow of the fuel.

Preferably, the at least one combustion chamber has a solid fuel combustion means.

Ideally, the solid fuel combustion means is located proximal to the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the solid fuel combustion means is in fluid communication with the combustion chamber.

Ideally, the solid fuel combustion means is in fluid communication with a portion of the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the solid fuel combustion means is a flame.

Ideally, the means for adjusting the volume of the combustion chamber is slidably displaceable in a direction parallel to the main plane of a floor of the combustion chamber.

Ideally, the means for adjusting the volume of the combustion chamber is capable of reducing the volume at least a portion of the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the means for delivering solid fuel to the at least one combustion chamber comprises a fuel chute.

Preferably, the means for adjusting the volume of the combustion chamber is capable of reducing the volume of the fuel chute of the means for delivering solid fuel.

Advantageously, this constricting of at least a portion of the means for delivering solid fuel to the at least one combustion chamber limits the amount of solid fuel capable of entering into the combustion chamber via the delivery means.

Preferably, the means for adjusting the volume of the combustion chamber comprises a body portion and a handle which displaces the body portion upon application of force to the handle by an operator.

Ideally, the guide means of the combustion chamber guides the body portion of the means for adjusting the volume of the combustion chamber.

Preferably, the guide means and the handle are in substantial alignment to the combustion means of the at least one combustion chamber.

Ideally, actuation of the handle by an operator slides the means for adjusting the volume of the combustion chamber towards and away from the origin of the combustion means.

Preferably, a means for delivering solid fuel to the at least one combustion chamber comprises the chute.

Ideally, the burner for solid fuel comprises choke means.

Preferably, the choke means is disposed between the combustion chamber and the fuel inlet.

Ideally, the choke means is disposed proximal to the combustion chamber.

Preferably, the choke means is disposed above the combustion chamber.

Ideally, the choke means is disposed proximal to the chute of the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the choke means is moveable transverse to a direction of the flow of the fuel.

Ideally, the choke means is capable of adjusting the volume of the chute of the means for delivering solid fuel to the at least one combustion chamber.

Preferably, the choke means is capable of closing off the chute of the means for delivering solid fuel to the least one combustion chamber.

Ideally, the choke means comprises a slidable main body.

Preferably, the slidable main body of the choke means is slidable into and out of the chute of the means for delivering solid fuel to the at least one combustion chamber.

Ideally, the choke means comprises a manually operable handle coupled to the mean body.

Preferably, the choke means is moveably displaceable traverse to the means for delivering solid fuel to the at least one combustion chamber.

Ideally, the choke means moveably displaceable traverse to a direction of flow of the fuel.

Preferably, the choke means is moveably displaceable perpendicular to a direction of flow of the fuel.

Ideally, the choke means is moveably displaceable in a direction parallel to the ceiling of the combustion chamber.

Preferably, the choke means is moveably displaceable in a direction parallel to the moving direction of the means for adjusting the volume of the combustion chamber.

Ideally, the at least one combustion chamber with the means for adjusting the volume of the combustion chamber is a primary combustion chamber.

Preferably, the burner for solid fuel comprises a secondary combustion chamber.

Preferably, the secondary combustion chamber is at least partly formed by a grate.

Ideally, the grate of the secondary combustion chamber is capable of retaining the solid fuel within the secondary combustion chamber for at least partial but preferably complete combustion of the solid fuel.

Preferably, the burner for solid fuel comprises an ash tray.

Ideally, at least a part of the ash tray is removable.

Preferably, the means for delivering solid fuel to the at least one combustion chamber is directly above the primary combustion chamber.

Ideally, the primary combustion chamber is directly above the secondary combustion chamber.

Advantageously, the burner can take advantage of gravity fed fuel and gravity acting on the fuel as it passes down through the stacked combustion chambers.

Preferably, during combustion the solid fuel passes from the primary combustion chamber into the secondary combustion chamber.

Ideally, upon entry to the secondary combustion chamber the combusting solid fuel is retained until fully combusted. After which, it drops into the ashtray.

Preferably, the secondary combustion chamber is capable of retaining combusting fuel of a size smaller relative to the fuel held within the primary combustion chamber.

Preferably, the means for delivering solid fuel to the at least one combustion chamber is substantially vertical.

Ideally, the means for delivering solid fuel to the at least one combustion chamber is vertical.

Preferably, the burner for solid fuel comprises an induction chamber for extracting heat from the at least one combustion chamber.

Ideally, the induction chamber guides the heat to a connected heat load.

Preferably, the heat load is any one of a water boiler, water heater, outdoor patio heater, space heater, oven or cooker.

Ideally, the floor of primary combustion chamber and/or the secondary combustion comprises a grate comprising a plurality of spaced apart rods.

Alternatively, the floor of primary combustion chamber and/or the secondary combustion comprises a grate comprising a plurality of spaced apart apertures.

Ideally, the solid fuel is a biomass fuel.

Preferably, the biomass fuel is wood pellets or the like.

The invention will now be described with reference to the accompanying drawing which shows by way of example only one embodiment of an apparatus in accordance with the invention.

Figure 1 is a vertical cross sectional view of the burner with the choke closing the chute;

Figure 2 is a vertical cross sectional view of the burner with the choke partially open and primary combustion chamber operating at maximum volume;

Figure 3 is a vertical cross sectional view of the burner with the choke fully open and primary combustion chamber operating at maximum volume;

Figure 4 is a vertical cross sectional view of the burner with the choke partially open and primary combustion chamber operating at a partially reduced volume;

Figure 5 is a perspective partly exploded rear view of the burner partly cut away;

Figure 6 is a second perspective rear view of the burner partly again cut away;

Figure 7 is a vertical section view through the burner.

In the drawing, there is shown a solid fuel burner indicated generally by the reference numeral 1 having a primary combustion chamber 2 and a chute 3 for delivering solid fuel to the primary combustion chamber 2. An arrangement 4 for adjusting the volume of the primary combustion chamber 2 is shown. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is a manual adjustment assembly 4. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable to adjust the width of the primary combustion chamber 2. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable to adjust the surface area of the floor of the primary combustion chamber 2. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable traverse to the chute 3 for delivering solid fuel to the primary combustion chamber 2. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable traverse to the direction of flow of the fuel. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable perpendicular to the direction of flow of the fuel. The arrangement 4 for adjusting the volume of the primary combustion chamber 2 is moveably displaceable in a direction parallel to the floor 5 of the primary combustion chamber 2.

Advantageously, the ability to adjust the volume of the primary combustion chamber 2 allows an operator to adjust the heat output of the solid fuel burner 1 in a simple and efficient way conserving energy and costs to the operator. The volume of the primary combustion chamber 2 can be adjusted prior to solid fuel combustion, during combustion and after combustion. The combustion chamber 2 is at formed by a grate arrangement 6, see Figures 5 and 6. The grate 6 of the primary combustion chamber 2 is capable of retaining the solid fuel within the combustion chamber for at least partial combustion of the solid fuel. Additionally, the arrangement 4 for adjusting the volume of the combustion chamber is at least partly formed by a grate 7, see Figures 5 to 7. The grate 7 of the arrangement 4 for adjusting the volume of the combustion chamber 2 is capable of retaining the solid fuel within the combustion chamber 2 for at least partial combustion of the solid fuel.

The primary combustion chamber 2 has a guide arrangement being provided by the floor grate 6 and side walls 8, 9 see Figures 5 to 7 of the primary chamber 2 to guide the movement of the arrangement 4 for adjusting the volume of the combustion chamber 2 into and out of the combustion chamber 2. The arrangement 4 for adjusting the volume of the combustion chamber 2 is slidably displaceable traverse to the direction of flow of the fuel and in the embodiment shown in the drawings is slidably displaceable perpendicular to the direction of flow of the fuel. The primary combustion chamber 2 has a solid fuel combustion member in the form of a flame generator. The flame generator is located proximal to the arrangement 4 for delivering solid fuel to the primary combustion chamber 2. The flame generator is in fluid communication with the combustion chamber 2 and/or with a portion of the chute 3 for delivering solid fuel to the primary combustion chamber 2. The arrangement 4 for adjusting the volume of the combustion chamber 2 is slidably displaceable in a direction parallel to the main plane of the floor 5 of the combustion chamber 2. The arrangement 4 for adjusting the volume of the combustion chamber 2 is also capable of reducing the volume of the chute 3 for delivering solid fuel to the primary combustion chamber 2. The arrangement 4 for delivering solid fuel to the primary combustion chamber 2 comprises fuel chute 3. Advantageously, this reduction of the volume of the chute 3 for delivering solid fuel to the combustion chamber 2 limits the amount of solid fuel capable of entering into the combustion chamber 2 via the chute 3.

The arrangement 4 for adjusting the volume of the combustion chamber 2 comprises a body portion 11 and a handle 12 which displaces the body portion 11 upon application of force to the handle 12 by an operator. The guide arrangement 5, 8, 9 of the combustion chamber 2 guides the body portion 11 of the arrangement 4 for adjusting the volume of the combustion chamber 2. The guide arrangement 5, 8, 9 and the handle 12 are in substantial alignment with the flame generator of the primary combustion chamber 2. Actuation of the handle 12 by an operator slides the arrangement 4 for adjusting the volume of the combustion chamber 2 towards and away from the flame generator.

The burner 1 for solid fuel comprises a choke arrangement 14 .The choke arrangement 14 is disposed between the primary combustion chamber 2 and the fuel inlet. The choke arrangement 14 is disposed proximal to the primary combustion chamber 2. The choke arrangement 14 is disposed above the combustion chamber 2. The choke arrangement 14 is disposed proximal to the chute 3 of the arrangement 4 for delivering solid fuel to the primary combustion chamber 2. The choke arrangement 14 is moveable transverse to the direction of the flow of the fuel. The choke arrangement 14 is capable of adjusting the volume of the chute 3 for delivering solid fuel to the primary combustion chamber 2. The choke arrangement 14 is capable of closing off the chute 3 for delivering solid fuel to the primary combustion chamber 2. The choke arrangement 14 has a slidable main body 15. The choke arrangement 14 has the slidable main body 15 slidable into and out of the chute 3 for delivering solid fuel to the primary combustion chamber 2. The choke arrangement 14 has a manually operable handle 16 coupled to the main body 15. The choke arrangement 14 is moveably displaceable traverse to the chute 3 for delivering solid fuel to the primary combustion chamber 2. The choke arrangement 14 is moveably displaceable traverse to the direction of flow of the fuel and is moveably displaceable perpendicular to the direction of flow of the fuel in the embodiments shown in the drawings. The choke arrangement 14 is moveably displaceable in a direction parallel to the ceiling of the combustion chamber 2. The choke arrangement 14 is moveably displaceable in a direction parallel to the moving direction of the arrangement 4 for adjusting the volume of the combustion chamber 2.

The burner 1 for solid fuel has a secondary combustion chamber 18. The secondary combustion chamber 18 is at least partly formed by a grate 19 see Figure 6. The grate 19 of the secondary combustion chamber 18 is capable of retaining the solid fuel within the secondary combustion chamber 18 for at least partial but preferably complete combustion of the solid fuel. The burner 1 for solid fuel comprises an ash tray 21. At least a part of the ash tray 21 is removable to allow cleaning of the burner 1.

The chute 3 for delivering solid fuel to the primary combustion chamber 2 is directly above the primary combustion chamber 2. The primary combustion chamber 2 is directly above the secondary combustion chamber 18. Advantageously, the burner 1 can take advantage of gravity fed fuel and gravity acting on the fuel as it passes down through the vertically stacked combustion chambers 2, 18. During combustion the solid fuel passes from the primary combustion chamber 2 into the secondary combustion chamber 18. Upon entry to the secondary combustion chamber 18 the combusting solid fuel is retained until fully combusted. After which, if drops into the ashtray 21. The secondary combustion chamber 18 is capable of retaining combusting fuel of a size smaller relative to the fuel held within the primary combustion chamber 2. The chute 3 for delivering solid fuel to the combustion chamber 2 is substantially vertical. The burner 1 for solid fuel comprises an induction chamber 22 for extracting heat from the combustion chamber. The induction chamber 22 guides the heat to the connected heat load. The burner 1 when attached to the heat load uses natural draw to create a clean and intense burn with high efficiency producing minimal ash. The flames are drawn horizontally through the outlet port of the induction chamber into the heat load apparatus. When running at operational temperatures the burner 1 uses preheated air through an air intake which also incorporates the second combustion chamber grate 19. This aids the burner to completely burn the fuel which contributes to the high operating efficiency of the burner 1. Ash then discharges through the second combustion chamber grate 19 into the ash tray 21. The heat load apparatus is any one of a water boiler, water heater, outdoor patio heater, space heater, oven or cooker. The fuel is a biomass fuel such as wood pellets or the like.

Claims

1. A burner for solid fuel comprising: at least one combustion chamber, a means for delivering solid fuel to the at least one combustion chamber and means for adjusting the volume of the combustion chamber wherein the means for adjusting the volume of the combustion chamber is moveably displaceable to adjust the width of the at least one combustion chamber.

2. A burner for solid fuel as claimed in claim 1, wherein the means for adjusting the volume of the at least one combustion chamber is a manual adjustment means.

3. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is moveably displaceable to adjust the surface area of a floor of the at least one combustion chamber.

4. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is moveably displaceable traverse to the means for delivering solid fuel to the at least one combustion chamber.

5. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is moveably displaceable traverse to a direction of flow of the fuel.

6. A burner for solid fuel as claimed in any one of claims 1 to 4, wherein the means for adjusting the volume of the combustion chamber is moveably displaceable perpendicular to a direction of flow of the fuel.

7. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is moveably displaceable in a direction parallel to a floor of the combustion chamber.

8. A burner for solid fuel as claimed in any one of the preceding claims, wherein the volume of the combustion chamber can be adjusted prior to solid fuel combustion, during combustion and after combustion.

9. A burner for solid fuel as claimed in any one of the preceding claims, wherein the at least one combustion chamber is at least partly formed by a grate.

10. A burner for solid fuel as claimed in claim 9, wherein the grate of the at least one combustion chamber is capable of retaining the solid fuel within the at least one combustion chamber for at least partial combustion of the solid fuel.

11. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is at least partly formed by a grate.

12. A burner for solid fuel as claimed in claim 11, wherein the grate of the means for adjusting the volume of the combustion chamber is capable of retaining the solid fuel within the at least one combustion chamber for at least partial combustion of the solid fuel.

13. A burner for solid fuel as claimed in any one of the preceding claims, wherein the at least one combustion chamber comprises guide means to guide the movement of the means for adjusting the volume of the combustion chamber into and out of the combustion chamber.

14. A burner for solid fuel as claimed in any one of claims 1 to 5 or any one of claims 7 to 13, wherein the means for adjusting the volume of the combustion chamber is slidably displaceable traverse to a direction of flow of the fuel.

15. A burner for solid fuel as claimed in any one of claims 1 to 4 or any one of claims 6 to 13, wherein the means for adjusting the volume of the combustion chamber is slidably displaceable perpendicular to a direction of flow of the fuel.

16. A burner for solid fuel as claimed in any one of the preceding claims, wherein the at least one combustion chamber has a solid fuel combustion means.

17. A burner for solid fuel as claimed in claim 16, wherein the solid fuel combustion means is located proximal to the means for delivering solid fuel to the at least one combustion chamber.

18. A burner for solid fuel as claimed in any one of claims 16 to 17, wherein the solid fuel combustion means is in fluid communication with the combustion chamber.

19. A burner for solid fuel as claimed in any one of claims 16 to 18, wherein the solid fuel combustion means is in fluid communication with a portion of the means for delivering solid fuel to the at least one combustion chamber.

20. A burner for solid fuel as claimed in any one of claims 16 to 19, wherein the solid fuel combustion means is a flame.

21. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is slidably displaceable in a direction parallel to the main plane of a floor of the combustion chamber.

22. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber is capable of reducing the volume of at least a portion of the means for delivering solid fuel to the at least one combustion chamber.

23. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for delivering solid fuel to the at least one combustion chamber comprises a fuel chute.

24. A burner for solid fuel as claimed in claim 23, wherein the means for adjusting the volume of the combustion chamber is capable of reducing the volume of the fuel chute of the means for delivering solid fuel.

25. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for adjusting the volume of the combustion chamber comprises a body portion and a handle which displaces the body portion upon application of force to the handle by an operator.

26. A burner for solid fuel as claimed in claim 25 when dependent on claim 13 or any one of claims 14 to 24 when dependent on claim 13, wherein the guide means of the combustion chamber guides the body portion of the means for adjusting the volume of the combustion chamber.

27. A burner for solid fuel as claimed in claim 25 or claim 26 when dependent on claim 13 or any one of claims 14 to 24 when dependent on claim 13, wherein the guide means and the handle are in substantial alignment to the combustion means of the at least one combustion chamber.

28. A burner for solid fuel as claimed in any one of claims 25 to 27 when dependent on claim 13 or any one of claims 16 to 24 when dependent on claim 13, wherein actuation of the handle by an operator slides the means for adjusting the volume of the combustion chamber towards and away from the origin of the combustion means.

29. A burner for solid fuel as claimed in any one of the preceding claims, wherein the burner for solid fuel comprises choke means.

30. A burner for solid fuel as claimed in claim 29, wherein the choke means is disposed between the combustion chamber and a fuel inlet.

31. A burner for solid fuel as claimed in any one of claims 29 to 30 when dependent on claim 23, wherein the choke means is disposed proximal to the chute of the means for delivering solid fuel to the at least one combustion chamber.

32. A burner for solid fuel as claimed in any one of claims 29 to 31, wherein the choke means is moveable transverse to a direction of the flow of the fuel.

33. A burner for solid fuel as claimed in any one of claims 29 to 32 when dependent on claim 23, wherein the choke means is capable of adjusting the volume of the chute of the means for delivering solid fuel to the at least one combustion chamber.

34. A burner for solid fuel as claimed in any one of claims 29 to 33 when dependent on claim 23, wherein the choke means is capable of closing off the chute of the means for delivering solid fuel to the least one combustion chamber.

35. A burner for solid fuel as claimed in any one of claims 29 to 34, wherein the choke means comprises a slidable main body.

36. A burner for solid fuel as claimed in claim 35 when dependent on claim 23, wherein the slidable main body of the choke means is slidable into and out of the chute of the means for delivering solid fuel to the at least one combustion chamber.

37. A burner for solid fuel as claimed in any one of claims 29 to 36, wherein the choke means comprises a manually operable handle coupled to the means body.

38. A burner for solid fuel as claimed in any one of claims 29 to 37, wherein the choke means is moveably displaceable traverse to the means for delivering solid fuel to the at least one combustion chamber.

39. A burner for solid fuel as claimed in any one of claims 29 to 38, wherein the choke means is moveably displaceable traverse to the direction of flow of the fuel.

40. A burner for solid fuel as claimed in any one of claims 29 to 38, wherein the choke means is moveably displaceable perpendicular to a direction of flow of the fuel.

41. A burner for solid fuel as claimed in any one of claims 29 to 40, wherein the choke means is moveably displaceable in a direction parallel to a ceiling of the combustion chamber.

42. A burner for solid fuel as claimed in any one of claims 29 to 40, wherein the choke means is moveably displaceable in a direction parallel to the moving direction of the means for adjusting the volume of the combustion chamber.

43. A burner for solid fuel as claimed in any one of the preceding claims, wherein the at least one combustion chamber with the means for adjusting the volume of the combustion chamber is a primary combustion chamber.

44. A burner for solid fuel as claimed in any one of the preceding claims, wherein the burner for solid fuel comprises a secondary combustion chamber.

45. A burner for solid fuel as claimed in claim 44, wherein the secondary combustion chamber is at least partly formed by a grate.

46. A burner for solid fuel as claimed in claim 45, wherein the grate of the secondary combustion chamber is capable of retaining the solid fuel within the secondary combustion chamber for at least partial combustion of the solid fuel.

47. A burner for solid fuel as claimed in any one of the preceding claims, wherein the burner for solid fuel comprises an ash tray.

48. A burner for solid fuel as claimed in claim 47, wherein at least a part of the ash tray is removable.

49. A burner for solid fuel as claimed in any one of claims 43 to 48, wherein the means for delivering solid fuel to the at least one combustion chamber is directly above the primary combustion chamber.

50. A burner for solid fuel as claimed in any one of claims 44 to 49 when dependent on claim 43, wherein the primary combustion chamber is directly above the secondary combustion chamber.

51. A burner for solid fuel as claimed in any one of claims 44 to 50 when dependent on claim 43, wherein during combustion the solid fuel passes from the primary combustion chamber into the secondary combustion chamber.

52. A burner for solid fuel as claimed in any one of claims 44 to 46 or claims 48 to 51 when dependent on claim 47, wherein upon entry to the secondary combustion chamber the combusting solid fuel is retained until fully combusted, after which, it drops into the ashtray.

53. A burner for solid fuel as claimed in any one of claims 44 to 52 when dependent on claim 43, wherein the secondary combustion chamber is capable of retaining combusting fuel of a size smaller relative to the fuel held within the primary combustion chamber.

54. A burner for solid fuel as claimed in any one of the preceding claims, wherein the means for delivering solid fuel to the at least one combustion chamber is substantially vertical.

55. A burner for solid fuel as claimed in any one of the preceding claims, wherein the burner for solid fuel comprises an induction chamber for extracting heat from the at least one combustion chamber.

56. A burner for solid fuel as claimed in claim 55, wherein the induction chamber guides the heat to a connected heat load.

57. A burner for solid fuel as claimed in claim 56, wherein the heat load is any one of a water boiler, water heater, outdoor patio heater, space heater, oven or cooker.

58. A burner for solid fuel as claimed in any one of the preceding claims, wherein the solid fuel is a biomass fuel.

59. A burner for solid fuel as claimed in any one of claims 43 to 58, wherein a floor of primary combustion chamber and/or the secondary combustion comprises a grate comprising a plurality of spaced apart rods.

60. A burner for solid fuel as claimed in any one of claims 43 to 58, wherein a floor of primary combustion chamber and/or the secondary combustion comprises a grate comprising a plurality of spaced apart apertures.