Abstract: In a premixing combustion device (1) for a heating boiler, comprising a blower (2) which delivers a combustion mixture composed of fuel and air from an outlet opening (8) of the blower (2) via a burner cylinder (9) to a combustion zone, wherein a mixing device (3) arranged upstream of the blower (2) prepares the combustion mixture, it is sought to provide a solution which, in a structurally simple manner, ensures reliable starting of the heating boiler and prevents failures. This is achieved by means of a throughflow reduction device (10) which is arranged between the outlet opening (8) of the blower (2) and the burner cylinder (9) and which has a throughflow reduction element (13) which can be adjusted between a position in which it opens the outlet opening (8) of the blower (2) and a position in which it reduces the size of the outlet opening (8) of the blower (2).

Abstract: The grate is used for burning a granular fuel material, for instance a biomass material, to be fed onto a loading area of the grate while a primary air feed is coming from below the grate. The grate includes a perforated bed floor having a downwardly-sloping upper surface converging towards a discharge opening where char is concentrated as the granular fuel material is burned during operation. The grate also includes an elongated and bottom-perforated char-receiving conduit positioned immediately under the bed floor. The char-receiving conduit has an inlet end positioned under the discharge opening, and an outlet end that is opposite the inlet end. The char-receiving conduit downwardly slopes between the inlet end and the outlet end. A method of burning a granular fuel material is also disclosed. The proposed concept can increase the overall thermal efficiency of a heat generator and reduce gas and particle emissions in the atmosphere.

Abstract: In a premixing combustion device (1) for a heating boiler, comprising a blower (2) which delivers a combustion mixture composed of fuel and air from an outlet opening (8) of the blower (2) via a burner cylinder (9) to a combustion zone, wherein a mixing device (3) arranged upstream of the blower (2) prepares the combustion mixture, it is sought to provide a solution which, in a structurally simple manner, ensures reliable starting of the heating boiler and prevents failures. This is achieved by means of a throughflow reduction device (10) which is arranged between the outlet opening (8) of the blower (2) and the burner cylinder (9) and which has a throughflow reduction element (13) which can be adjusted between a position in which it opens the outlet opening (8) of the blower (2) and a position in which it reduces the size of the outlet opening (8) of the blower (2).