Boiler burner for solid fuels of the biomass or tyre type and boiler comprising such burner

Abstract

The invention relates to a burner for solid fuel such as biomass or tyres, that comprises a heating body in the shape of a cylinder ( 1,1′, 1 ′) with solid fuel supply means and means for the inlet of primary air ( 13, 13′, 13 ′) as oxidant, said cylinder being provided with a plate ( 3,3′,3 ′) in its lower part. The invention comprises placing the plate above the means for the inlet of primary air ( 13, 13′, 13 ′), wherein the plate has through holes and is arranged so as to receive the fuel without the fuel flowing therethrough, and said burner further includes inside said cylinder ( 1, 1′,1 ′) means for generating a negative pressure within the burner so as to generate a primary air circulation from the underside of the plate ( 3, 3′,3 ′) and through said plate and the fuel resting thereon up to a gas outlet duct ( 4, 4′, 4 ′) in the upper portion of said burner. Application in the combustion of biomass, tyres and the like.

1 . Burner of solid fuel, such as biomass and tires, comprising a heating body in the form of a cylinder equipped with solid fuel feed means and primary air inlet means as oxidant, said cylinder being provided at its lower part with a plate, characterized in that said plate is positioned above the primary air inlet means, that plate provided with through holes being set up to receive the fuel without the fuel flowing through, and said burner further containing inside said cylinder means generating a partial vacuum in the burner, so as to create a primary air circulation from the bottom of said plate through the latter and the fuel resting on top up to a gas outlet duct in the upper part of said burner. 
   
   
       2 . Burner according to  claim 1 , characterized in that the means capable of creating a partial vacuum inside the burner consist of a compressed air feed means positioned in the upper part of the cylinder of the burner and generating a Venturi effect creating the partial vacuum. 
   
   
       3 . Burner according to  claim 2 , characterized in that the air from the Venturi effect also supplies the oxidant necessary for combustion in an outlet pipe of the burner. 
   
   
       4 . Burner according to  claim 1 , characterized in that the regular solid fuel supply means consist of a feed pipe engaged through an opening provided in the cylinder and connected to a fuel reserve by means of a rotary feeder which ensures the regular fuel supply. 
   
   
       5 . Burner according to  claim 1 , characterized in that the air inlet means consists of a space provided in the bottom plate of said burner, into which the air is fed. 
   
   
       6 . Burner according to  claim 1 , characterized in that it contains a means of scraping the bottom plate, also serving to even the fuel level so that the air will pass regularly. 
   
   
       7 . Burner according to  claim 6 , characterized in that it contains inside the cylinder a shaft, preferably tubular, which extends across the upper wall of the cylinder to the bottom wall, this shaft being rotatable at its end outside the cylinder, while its free end in the lower part of the cylinder is equipped with scraping means. 
   
   
       8 . Burner according to  claim 7 , characterized in that it contains means for translation drive of the shaft so as to lower the scraping means from its fuel spreading position to a position of contact with the plate, so that the scraping means will then serve to grind the residues present on the nozzle in order to make them pass the through holes of the nozzle. 
   
   
       9 . Burner according to  claim 6 , characterized in that it contains inside the cylinder a shaft, preferably tubular, which extends across the upper wall of the cylinder to the bottom wall, this shaft being driven rotatably at its end outside the cylinder, while its free end bears the bottom plate, which is thus driven in rotation with said shaft, the scraping means being mounted fixed in rotation in the cylinder. 
   
   
       10 . Burner according to  claim 9 , characterized in that the bottom plate preferably has a diameter roughly corresponding to the internal diameter of the cylinder, while the space constituting the air inlet means, provided under said bottom plate, has a greater diameter. 
   
   
       11 . Burner according to  claim 9 , characterized in that it contains means for translation drive of the shaft in order to lower the bottom plate in the space, thus freeing the periphery of the plate, the scraping means also being lowered with a wider amplitude, so that it abuts said bottom plate in its scraping position. 
   
   
       12 . Burner according to  claim 11 , characterized in that the bottom of the space is mounted pivoting on a pin, so as to open when the shaft, which is in one piece with said bottom, is lowered in order to lower the bottom plate, and so as to close when the shaft is raised again. 
   
   
       13 . Burner according to  claim 11 , characterized in that the shaft contains in its upper part outside the cylinder a pin extending crosswise to said shaft, that pin being mounted pivoting at one end, which is in a position lower than a pivot point of this pin on the shaft, lower in turn than the opposite end of the pin mounted at the end of the rod of a jack that is preferably pneumatic, the scraping means being borne by a shaft extending parallel to shaft and the end of which is mounted pivoting at on the pin in proximity to the end. 
   
   
       14 . Burner according to  claim 1 , characterized in that the primary air feed means consist of a pipe extending preferably centrally in the cylinder across the upper wall of the latter and entering under the plate of said burner through a central opening of sufficient section for the primary air. 
   
   
       15 . Burner according to  claim 14 , characterized in that the pipe is concentric to the shaft and surrounds the latter. 
   
   
       16 . Burner according to  claim 1 , characterized in that it further contains an outer casing defining with the cylinder an annular compartment in which the primary air is fed up to the air inlet means. 
   
   
       17 . Burner according to  claim 7 , characterized in that the rotary drive of the shaft is carried out simultaneously with the rotary feeder. 
   
   
       18 . Burner according to  claim 7 , characterized in that secondary air inlet means consisting of a pipe connected to primary air feed and/or inlet means extend into the cylinder and enter the upper part of the cylinder, so as to ensure a constant flame at the top of the burner at the level of the Venturi effect. 
   
   
       19 . Burner according to  claim 1 , characterized in that flame generating means, such as means of distribution of a gas such as propane or butane, are provided in the outlet pipe. 
   
   
       20 . Boiler for solid fuel such as biomass, having a burner, comprising a heating body in the form of a cylinder equipped with solid fuel feed means and primary air inlet means as oxidant, said cylinder being provided at its lower part with a plate, characterized in that said plate is positioned above the primary air inlet means, that plate provided with through holes being set up to receive the fuel without the fuel flowing through, and said burner further containing inside said cylinder means generating a partial vacuum in the burner, so as to create a primary air circulation from the bottom of said plate through the latter and the fuel resting on top up to a gas outlet duct in the upper part of said burner. 
   
   
       21 . Boiler according to  claim 20 , characterized in that the means of primary air feed from the boiler to the bottom of the burner are provided at the bottom of the boiler and consist of a pipe concentric to the gas outlets, which makes it possible to reheat the primary air and cool the outlet gases. 
   
   
       22 . Boiler according to  claim 20 , characterized in that contains a second stage of reheating of the return water from heating with the cooled gases of the first stage, a T-shaped gas outlet making it possible to take cooler gases at the bottom of the main body of the boiler, while the vertical part of the T-piece makes it possible to cool the cooler gases with water at lower temperature, a pipe enabling the water to be taken up at the top of the second heating body and to be injected in the bottom of the main body on the other side of a partition of the first stage of the boiler. 
   
   
       23 . Boiler according to  claim 20 , characterized in that it contains a boiler set up so that it can be positioned on the door of a standard type boiler.