Plant for Heating by Combustion of a Solid Fuel

Abstract

The invention relates to a heating plant. The plant comprises a combustion chamber for combustion of a solid fuel, an outlet from the combustion chamber, and a heat exchanger containing a cooling medium and arranged in connection with the combustion chamber. A flue duct is connected to the outlet of the combustion chamber and passes through the heat exchanger. Downstream the heat exchanger, a cyclone is arranged to separate ash from the flue gases, and a flue fan is arranged to draw flue gases through the flue duct. The flue duct and the flue fan are dimensioned to maintain a high velocity of flow in the flue duct, all the way from the outlet of the combustion chamber and up to the cyclone, in order to achieve a blasting effect on the inside of the flue duct by ash particles being drawn through the flue duct.

1 - 10 . (canceled) 
   
   
       11 . A heating plant comprising a combustion chamber for combustion of a solid fuel, an outlet from the combustion chamber, a heat exchanger arranged in connection with the combustion chamber, a flue duct connected to the outlet of the combustion chamber, which flue duct passes through the heat exchanger, such that heat energy in flue gases from the combustion chamber can be transferred to a cooling medium in the heat exchanger, an ash separator for separation of ash from the flue gases and positioned downstream from the heat exchanger, and a fan arranged in connection with the ash separator in order to draw the flue gases through the flue duct, wherein the flue duct and the fan are dimensioned to maintain a velocity of flow of at least 15 m/s in the flue duct, all the way from the outlet of the combustion chamber and up to the ash separator, in order to achieve a blasting effect on the inside of the flue duct by ash particles being drawn through the flue duct. 
   
   
       12 . A heating plant according to  claim 11 , wherein the flue duct and the fan are dimensioned to maintain a velocity of flow of at least 18 m/s all the way from the outlet of the combustion chamber and up to the ash separator. 
   
   
       13 . A heating plant according to  claim 11 , wherein parts of the flue duct project from the heat exchanger, which parts are detachable from the rest of the flue duct, such that the flue duct becomes accessible for cleaning. 
   
   
       14 . A heating plant according to  claim 11 , wherein the heating plant comprises no more than a single flue duct. 
   
   
       15 . A heating plant according to  claim 11 , wherein the ash separator is a cyclone, the heating plant further comprising an ash collector that is detachably arranged at a lower end of a conduit from the cyclone. 
   
   
       16 . A heating plant according to  claim 11 , wherein a movable ash scraper is arranged in the combustion chamber in order to be able to shove ashes towards the outlet of the combustion chamber. 
   
   
       17 . A heating plant according to  claim 11 , wherein the outlet from the combustion chamber is positioned at a bottom of the combustion chamber. 
   
   
       18 . A heating plant according to  claim 11 , wherein the fan is arranged to be operated with a variable rotational speed. 
   
   
       19 . A heating plant according to  claim 11 , wherein the fan is arranged to be operated with a variable blade angle. 
   
   
       20 . A heating plant according to  claim 18 , wherein the fan is arranged to be controlled as a function of a pressure level in the combustion chamber. 
   
   
       21 . A heating plant according to  claim 19 , wherein the fan is arranged to be controlled as a function of a pressure level in the combustion chamber.