System For Milling And Air-Water Cooling Bottom Ash From Heating Furnaces For Solid Fuels

Abstract

The present invention relates to a milling and water-air combined cooling system for bottom ash from heating furnaces for solid fuels, able to maximize the efficiency in milling and cooling also large ash lumps at high temperature and in improving cooling air fluid dynamics which passes said system in counter-flow. The system comprises a crusher ( 1 ) provided with a pre-crusher integral with the crusher's ( 1 ) port, a water cooling system ( 3 - 4 ), and a separation ( 5 - 6 ) of the flow of the fine material entering the crusher ( 1 ) from the lump sized ash. The pre-milling device ( 2 ) allows a partial milling of the large lumps and it is actuated by laser or equivalent sensors ( 7 ) which detect the presence of ash agglomerates in the milling area. The cooling water passes preferably throughout the shaft ( 8 ) of the toothed rotor ( 9 ) and/or throughout the fixed slab ( 10 ) and moves therefrom, through suitable ducts ( 4 ) and nozzles ( 3 ), to the milling area. The water intervention is automated depending on the crusher rotor's ( 9 ) or casing's ( 11 ) temperature detected by suitable sensors ( 12 ). The flow separation of the fine material is achieved creating an opening ( 13 ) at the rear wall of the crusher and isolating it by a counterweight or automatic valve ( 5 ) at the unloading channel ( 14 ) and a closing shield ( 6 ) downstream of the traction head of the fine ash recuperator ( 15 ).

1 . A milling and air and water cooling system for bottom ash from heating furnaces for solid fuels, able to maximize efficiency in:
 milling and cooling also large ash lumps at high temperature and improving cooling air fluid dynamics using the integrated action of a pre-crusher ( 2 ) integral with the crusher's ( 1 ) port, a water cooling system  3 - 4  and the separation of the fine material flow, entering the crusher ( 1 ), from the lump sized ash, that permits the most suitable passing of the crusher ( 1 ) for the cooling air counter-flow relative to the ash flow, avoiding entrainment of the recuperated fine material.   
   
   
       2 . The milling and air and water cooling system according to  claim 1  characterized by the presence of a pre-crusher ( 2 ) integral with the crusher's ( 1 ) port formed by slabs with punches ( 20 ), made of suitable anti-wear material, which slide opposing on a fixed frame ( 21 ) connected to the port of the crusher ( 1 ), and actuated by hydraulic cylinders ( 22 ), functioning as pre-crusher of large ash lumps obstructing the crusher's ( 1 ) inlet thanks to the action of the slabs with punches ( 20 ). 
   
   
       3 . The milling and air and water cooling system according to  claim 1  characterized by the fact that water of the cooling system passes preferably throughout the shaft ( 8 ) of the toothed rotor ( 9 ) and/or though the fixed slab ( 10 ) and moves therefrom, through suitable ducts ( 4 ) and nozzles ( 3 ), in the milling area cooling the ash entering the crusher ( 1 ) and indirectly the milling members ( 9 ). 
   
   
       4 . The milling and air and water cooling system according to  claim 1  characterized by the separation of the fine material inlet within the crusher ( 1 ) from the lump sized ash achieved by a dedicated opening ( 13 ) at the rear wall of the crusher ( 1 ), which is connected to the unloading channel ( 14 ) and a closing plate ( 6 ) downstream of the traction head of the fine ash recuperator ( 15 ); all of this allowing the counter-flow passing of the crusher for the cooling air avoiding entrainment of recuperated fine ash. 
   
   
       5 . The milling and air and water cooling system according to  claim 2  characterized by the fact that the pre-crusher's ( 2 ) intervention is controlled by a laser or equivalent sensor ( 7 ) which detects presence of large ash lumps in the milling area. 
   
   
       6 . The milling and air and water cooling system according to  claim 3  characterized by the fact that the water cooling intervention is controlled by the rotor's ( 9 ) and casing's ( 11 ) temperature value detected by suitable sensors ( 12 ) whilst the water flow rate adjustment to the nozzles ( 3 ) is carried out depending on the temperature of the ash exiting the crusher ( 1 ) detected by a suitable sensor ( 19 ) on the machine downstream the crusher ( 1 ). 
   
   
       7 . A system for crushing relatively large ash lumps or cinders from a solid fuel furnace which comprises
 a fine ash separator ( 15 ) for separating fine ash from the lumps or cinders;   a precrusher ( 2 ) adapted to receive from the separator ( 15 ) separated lumps or cinders;   a crusher ( 1 ) having an inlet in communication with the precrusher ( 2 ) and adapted to receive lumps or cinders processed in the precrusher ( 2 );   a crusher by-pass unloading conduit ( 14 ) for preventing separated ash from entering the crusher ( 1 );   a water supply ( 3 ,  4 ) for introducing cooling water into the crusher ( 1 ); and   means for introducing a counter current air flow through the crusher ( 1 ) and precrusher ( 2 ).