Equipment and method for enhancing combustion and heat transfer in a boiler by using sound

Abstract

The invention concerns equipment and a method for enhancing the combustion event and heat transfer in a heating boiler. According to the invention, the space above the major combustion zone in the combustion space of the heating boiler is equipped with sound sources, which are used to generate an acoustic field to enhance the combustion event and to achieve more complete combustion.

1 . Equipment for enhancing the combustion event and heat transfer in a heating boiler, said equipment comprising sound sources (S) in a space above the major combustion zone in a combustion space ( 11 ) of the heating boiler ( 10 ), which sound sources (S) generate an acoustic field in order to enhance the combustion event and a more complete combustion, characterised in that the sound sources (S) are placed in such a way that the acoustic pressure patterns generated by the sound sources (S) meet at angles of 20-90° sideways and/or vertically and that the sound sources (S) are fitted into the heating boiler ( 10 ) in such a way that the generated acoustic field is rotating.  
   
   
       2 . Equipment as defined in  claim 1 , characterised in that the acoustic field generated by the sound sources (S) is continuous.  
   
   
       3 . Equipment as defined in  claim 1  or  2 , characterised in that the acoustic pressure level generated by the sound sources (S) is no less than 130 dB at the place where the acoustic pressure patterns meet.  
   
   
       4 . Equipment as defined in any one of claims  1 - 3 , characterised in that the frequency of the sound generated by the sound sources (S) is in a range of 20-1000 Hz.  
   
   
       5 . Equipment as defined in any one of claims  1 - 4 , characterised in that the secondary and/or tertiary air of the heating boiler ( 10 ) or a part of that air has been supplied into the boiler through the sound sources (S).  
   
   
       6 . Equipment as defined in any one of claims  1 - 5 , characterised in that the sound sources (S) are fitted into the heating boiler ( 10 ) in such a way that the generated rotating acoustic field rotates in the direction of the positive acoustic pressure.  
   
   
       7 . Equipment as defined in any one of claims  1 - 6 , characterised in that the sound sources (S) are fitted into the heating boiler ( 10 ) in such a way that the sound frequency increases towards the top part of the heating boiler ( 10 ).  
   
   
       8 . Equipment as defined in any one of claims  1 - 7 , characterised in that the sound sources (S) are acoustic horns.  
   
   
       9 . Equipment as defined in any one of claims  1 - 7 , characterised in that the sound sources (S) are pneumatically operated continuous sirens.  
   
   
       10 . Equipment as defined in any one of claims  1 - 7 , characterised in that the sound sources (S) are sound sources (SP) based on a pulse burner.  
   
   
       11 . Equipment as defined in  claim 10 , characterised in that the fuel of the pulse burner (SP) functioning as sound source essentially includes a gaseous inflammable matter and an oxidiser.  
   
   
       12 . Equipment as defined in  claim 10  or  11 , characterised in that the pulse burner (SP) functioning as sound source includes an antechamber (SP 1 ), into which air under pressure is arranged to be supplied, a set of valves (V) opened and closed by pressure and separating the space between the antechamber (SP 1 ) and the combustion chamber (SP 2 ), and into which combustion chamber (SP 2 ) supply of fuel is arranged, and a sound horn (SP 3 ).  
   
   
       13 . Equipment as defined in  claim 12 , characterised in that a continuous supply of air under pressure is arranged into the antechamber (SP 1 ) of the pulse burner (SP) through an assembly (L 1 ).  
   
   
       14 . Equipment as defined in  claim 12  or  13 , characterised in that the supply of fuel into the combustion chamber (SP 2 ) of the pulse burner (SP) is arranged through an assembly (L 2 ).  
   
   
       15 . Equipment as defined in any one of claims  12 - 14 , characterised in that the pressure of the combustion chamber (SP 2 ) of the pulse burner (SP) discharges into the combustion space ( 11 ) of the heating boiler ( 10 ).  
   
   
       16 . Method for enhancing the combustion event and heat transfer in a heating boiler, in which method an acoustic field is generated with sound sources (S) in a space above the major combustion zone in a combustion space ( 11 ) of the heating boiler ( 10 ), characterised in that a rotating acoustic field is generated by sound sources (S), which are located on various sides and/or at different elevations of the heating boiler ( 10 ) in such a way that the acoustic pressure patterns generated by the sound sources (S) meet at angles 20-90° sideways and/or vertically.  
   
   
       17 . Method as defined in  claim 16 , characterised in that sound sources (SP) based on a pulse burner are used as sound sources (S).