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EP-4276354-B1 - PELLET BURNER

EP4276354B1EP 4276354 B1EP4276354 B1EP 4276354B1EP-4276354-B1

Inventors

  • ZHENG, YING

Dates

Publication Date
20260506
Application Date
20210923

Claims (10)

  1. A pellet burner, comprising: a burner body (1) having a combustion chamber (100), a top of the burner body (1) being open; and a feed opening (101) provided at a first sidewall (1001) of the burner body (1), wherein a through port for air intake and ash falling is provided at an underside of the burner body, wherein a grate structure configured to support pellet fuel (9) is provided above the through port, the grate structure comprising a first tier of supports (11) and a second tier of supports (12), the first tier of supports (11) and the second tier of supports (12) being secured to the burner body (1), wherein supports in the first tier (11) are disposed lower than adjacent supports in the second tier (12), and the second tier of supports (12) are staggered with the first tier of supports (11) in a vertical direction, wherein a first passage (102) for ash falling and air intake is provided between the first tier of supports (11) and the second tier of supports (12), wherein a width of the first passage (102) is smaller than a diameter D of the pellet fuel (9), and a spacing L2 between two adjacent supports in the second tier (12) is greater than D but smaller than 2D, the diameter D being in a range from about 4 mm to about 6 mm, and wherein the feed opening (101) is disposed above the grate structure with a height difference H, H being no less than 3D, such that the pellet fuel (9) drops from the feed opening (101) to strike loose burnt pellet fuel ash, and air entering via the through port disperses the burnt pellet fuel ash between adjacent first and second tiers of supports (11, 12).
  2. The pellet burner according to claim 1, wherein the first tier of supports (11) and the second tier of supports (12) extend in a direction vertical to a feed direction of the feed opening (101), a spacing L1 between two adjacent supports in the first tier (11) gradually increases from a side portion where the feed opening (101) is located towards an opposite side portion, and the spacing L2 between two adjacent supports in the second tier (12) gradually increases from the side portion where the feed opening (101) is located towards the opposite side portion.
  3. The pellet burner according to claim 1, wherein the first tier of supports (11) and the second tier of supports (12) are inclined downward from a side portion where the feed opening (101) is located towards an opposite side portion.
  4. The pellet burner according to claim 1, wherein the burner body (1) comprises an open bottom that forms the through port.
  5. The pellet burner according to claim 1, wherein a mounting port (103) for mounting an igniter (8) is provided at the first sidewall (1001) of the burner body (1), wherein the feed opening (101), the mounting port (103), and the grate structure are sequentially arranged from top to down, and wherein a spacing from the feed opening (101) to the mounting port (103) is greater than a spacing from the mounting port (103) to the grate structure.
  6. The pellet burner according to claim 5, wherein a middle air inlet (104) is further provided at the first sidewall (1001) of the burner body (1), the middle air inlet (104) being disposed no lower than the mounting port (103) and no higher than the feed opening (101), or wherein an upper air inlet (105) is further provided at the first sidewall (1001) of the burner body (1), the upper air inlet (105) being disposed no lower than the feed opening (101).
  7. The pellet burner according to claim 1, wherein the first tier of supports (11) and the second tier of supports (12) are bars, or wherein the grate structure is formed by an undulated sheet metal element, the first tier of supports (11) is formed at valleys of the undulated sheet metal element, the second tier of supports (12) are formed at peaks of the undulated sheet metal element, and through holes forming the first passage (102) are provided between the valleys and the peaks of the undulated sheet metal element.
  8. The pellet burner according to claim 1, wherein auxiliary supports (14) for sustaining bottom fire are provided under the first tier of supports (11), wherein the auxiliary supports (14) are disposed higher than the through port, and wherein the auxiliary supports(14) are located at a side below the feed opening (101) and cover an area not exceeding 1/2 of an area covered by the grate structure.
  9. The pellet burner according to claim 8, wherein the burner body (1) comprises a second sidewall (1002) and a third sidewall (1003) which are disposed at two sides of the first sidewall (1001), respectively, and wherein the second sidewall (1002) and the third sidewall (1003) are extended into a splayed configuration towards two sides along a feed direction of the feed opening (101).
  10. The pellet burner according to claim 9, wherein the first tier of supports (11) and the second tier of supports (12) are parallel to the feed direction of the feed opening (101), wherein the burner body further comprises a fourth sidewall (1004) connected with the second sidewall (1002), a fifth sidewall (1005) connected with the third sidewall (1003), and a sixth sidewall (1006) connected to the fourth sidewall (1004) and the fifth sidewall (1005), and wherein the fourth sidewall (1004) and the fifth sidewall (1005) are parallel to the first tier of supports (11) and the second tier of supports (12), and the sixth sidewall (1006) is vertical to the feed direction of the feed opening (101).

Description

FIELD Thepresent disclosure relates to the field of combustion apparatuses, and more particularly relates to a pellet burner. BACKGROUND For conventional pellet stoves, e.g., barbecue stoves, a burner adopted basically has an enclosed bottom structure. Such a structure is very inconvenient to cleanse because after each use, the burnt pellet fuel ash has to be cleaned with a suction cleaner, rendering a poor user experience. Consider a heating stove as another example, which is generally configured with a layer of grate for holding fallen ash. However, as biomass pellet fuel usually has a cylindrical structure extruded from biomass raw materials, with a diameter of about 4-6 mm and a length ranging from 1cm to 6cm, and without an external force applied, the burnt pellet fuel ash would still maintain the original cylindrical shape, the ash hardly collapses down autonomously, rendering a poor ash falling efficiency and effect. After the combustion has lasted for a relatively long time, additional means is needed to break the ash loose so as to facilitate clearing the ash. Such additional means leads to a complex structure and increases the manufacturing cost. Furthermore, conventional pellet stoves need user involvement, inconvenient to use. US 5 617 841 A describes stoves fueled by biomass pellets provided with a grate assembly that supports the pellets for combustion and directs combustion gas into the fire, the grate assembly including a passive grate of equally or unequally spaced rods. CN 202 813 454 U describes a stove comprising a combustion chamber and a water storage chamber, wherein the combustion chamber is surrounded by the inner stove wall and is used for combusting fuel, the water storage chamber is placed between the inner wall of the stove and the outer wall of the stove and is used for heating water flow. A water inlet and a water outlet which are in communication with the water storage chamber are placed on the stove. An ash bin which can be pulled is placed on the lower portion of the combustion chamber. A stove door is placed in the front of the combustion chamber and is used for adding fuel into the combustion chamber and ventilating. A smoke flue is placed on the back position of the combustion chamber. A tube-type stove grate composed of a plurality of stove pipes is placed between the combustion chamber and the ash bin, wherein the stove pipes are parallelly placed at intervals and two ends of the plurality of the stove pipes are communicated with the water storage chamber. SUMMARY The present invention provides a pellet burner, which enables automatic ash falling without user involvement in clearing the ash and offers a good ash falling effect. According to the present invention, a pellet burner comprises: a burner body having a combustion chamber, a top of the burner body being open; and a feed opening provided at a first sidewall of the burner body, wherein a through port for air intake and ash falling is provided at an underside of the burner body, wherein a grate structure configured to support pellet fuel is provided above the through port, the grate structure comprising a first tier of supports and a second tier of supports, the first tier of supports and the second tier of supports being secured to the burner body, wherein supports in the first tier are disposed lower than adjacent supports in the second tier, and the second tier of supports are staggered with the first tier of supports in a vertical direction, wherein a first passage for ash falling and air intake is provided between the first tier of supports and the second tier of supports, wherein a width of the first passage is smaller than a diameter D of the pellet fuel, and a spacing L2 between two adjacent supports in the second tier is greater than D but smaller than 2D. The diameter D is in a range from about 4 mm to about 6 mm. The feed opening is disposed above the grate structure with a height difference H, H being no less than 3D. The pellet fuel drops from the feed opening to strike loose burnt pellet fuel ash, and air entering from the through port disperses the burnt pellet fuel ash between adjacent first and second tiers of supports. According to an embodiment, the first tier of supports and the second tier of supports extend in a direction vertical to feed direction of the feed opening, a spacing L1 between two adjacent supports in the first tier gradually increases from a side portion where the feed opening is located towards an opposite side portion, and the spacing L2 between two adjacent supports in the second tier gradually increases from the side portion where the feed opening is located towards the opposite side portion. According to an embodiment, the first tier of supports and the second tier of supports are inclined downward from a side portion where the feed opening is located towards an opposite side portion. According to an embodiment, the burner body comprises an open bottom that forms the throu