Shaft sealing arrangement for a pump for delivering hot fluids

Abstract

A shaft sealing arrangement for a pump for delivering hot fluids includes a dynamic shaft seal ( 4 ), in particular a slide ring seal, in order to seal a rotatable shaft ( 2 ) relative to a housing ( 1 ), and a cooling ring ( 5 ) which is mounted in front of the dynamic shaft seal ( 4 ) in the direction of the pump interior and which surrounds the shaft ( 2 ) at a small spacing. The shaft sealing arrangement further includes an additional seal ( 8 ) which seals the shaft ( 2 ) in the region of the cooling ring ( 5 ) in order to reduce the feed of hot fluid into the gap between the shaft ( 2 ) and the cooling ring ( 5 ), with the additional seal ( 8 ) being formed as a brush seal.

1 . A shaft sealing arrangement for a pump for delivering hot fluids, wherein the shaft sealing arrangement is arranged in a housing ( 1 ) and includes a dynamic shaft seal ( 4 ), in particular a slide ring seal, in order to seal a rotatable shaft ( 2 ) relative to the housing ( 1 ), and a cooling ring ( 5 ) which is mounted in front of the dynamic shaft seal ( 4 ) in the direction of the pump interior and which surrounds the shaft ( 2 ) at a small spacing, characterized in that the shaft sealing arrangement includes an additional seal ( 8 ) between the housing ( 1 ) and the shaft ( 2 ) and/or between the housing ( 1 ) and a relief piston ( 10 ) for the axial pressure and/or between the cooling ring ( 5 ) and the shaft ( 2 ) in order to reduce the feed of hot fluid into the gap between the shaft ( 2 ) and the cooling ring ( 5 ); and in that the additional seal ( 8 ) is formed as a brush seal which includes a plurality of closely arranged fibres, bristles and/or wires as sealing elements which are distributed and secured in ring-like manner and extend with their free ends towards the shaft surface to be sealed.  
     
     
         2 . A shaft sealing arrangement in accordance with  claim 1 , wherein the fibres, bristles and/or wires of the brush seal ( 8 ) are flexible and/or are flexibly secured.  
     
     
         3 . A shaft sealing arrangement in accordance with  claim 1  or  claim 2 , wherein the fibres, bristles and/or wires of the brush seal ( 8 ) are arranged at an acute angle to the shaft surface and the tip of the angle extends in the running direction ( 12 ) of the shaft ( 2 ).  
     
     
         4 . A shaft sealing arrangement in accordance with any one of  claims 1  to  3 , wherein the length of the fibres, bristles and/or wires of the brush seal ( 8 ) is pre-determined such that they can be ground to a suitable length by the rotating shaft ( 2 ).  
     
     
         5 . A shaft sealing arrangement in accordance with any one of  claims 1  to  4 , wherein the brush seal ( 8 ) is arranged close to the side boundary of the cooling ring ( 5 ), towards the pump interior.  
     
     
         6 . A shaft sealing arrangement in accordance with any one of  claims 1  to  5 , wherein the cooling ring ( 5 ) is integrated in the housing ( 1 ).  
     
     
         7 . A shaft sealing arrangement in accordance with any one of  claims 1  to  6 , wherein the shaft ( 2 ) is provided with a thermo-sleeve ( 9 ) in the region of the cooling ring ( 5 ) and/or in the region of the brush seal ( 8 ).  
     
     
         8 . A pump for delivering hot fluids having a shaft sealing arrangement in accordance with any one of  claims 1  to  7 .  
     
     
         9 . A pump in accordance with  claim 8 , wherein the pump is designed as a boiler feed pump.  
     
     
         10 . A pump in accordance with  claim 8  or  claim 9 , wherein the pump is designed for fluid temperatures from 150 to 250° C. and for pressures from 60 to 360 bar.  
     
     
         11 . A shaft sealing arrangement for a pump for delivering hot fluids, wherein the shaft sealing arrangement is arranged in a housing ( 21 ) and includes a dynamic shaft seal in order to seal a rotatable shaft ( 22 ) relative to the housing ( 21 ), characterised in that the dynamic shaft seal is designed as a brush sealing arrangement ( 28 ) which includes a plurality of individual brush seals ( 28 ′), wherein the brush seals ( 28 ′) include a plurality of closely arranged fibres, brushes and/or wires ( 28   a ) which are distributed and secured in ring-like manner and which extend with their free ends towards the shaft surface to be sealed.  
     
     
         12 . A shaft sealing arrangement in accordance with  claim 11 , characterised in that the brush sealing arrangement ( 28 ) includes a section through which a barrier liquid and/or a flushing liquid flow.  
     
     
         13 . A shaft sealing arrangement in accordance with  claim 12 , wherein the barrier liquid and/or the flushing liquid has a lower temperature than the delivered fluids to achieve a cooling action.  
     
     
         14 . A shaft sealing arrangement in accordance with any one of  claims 11  to  13 , wherein a plurality of ring-like brush seals ( 28 ′) of the brush sealing arrangement are arranged next to one another as a packing.  
     
     
         15 . A pump for delivering hot fluids having a shaft sealing arrangement in accordance with any one of  claims 11  to  14 .