Compressed air supply for the operation of moving bed filters

Abstract

A method for supplying compressed air for the operation of moving bed filters by way a compressor is characterized by controlling the pressure of compressed air from the compressor by controlling the rotational speed of the compressor. A system for supplying compressed air is also provided. By use of the described method and system, substantial energy savings of approximately 50 percent can be achieved.

1 . A method for supplying compressed air for the operation of moving bed filters by means of a compressor, characterized by
 controlling the pressure of compressed air from the compressor by controlling the rotational speed of the compressor.   
     
     
         2 . The method according to  claim 1 , comprising using an electrical frequency control device for the control of the rotational speed of an electrical motor. 
     
     
         3 . The method according to  claim 1 , comprising controlling the rotational speed of a combustion engine by controlling the fuel/air mixture fed to the engine. 
     
     
         4 . The method according to  claim 1 , comprising condensing water vapor in the compressed air in an air supply system downstream of the compressor and discharging the condensed water. 
     
     
         5 . The method according to  claim 1 , comprising cooling the compressed air in order to condense the water vapor. 
     
     
         6 . The method according to  claim 1 , wherein a claw compressor is used. 
     
     
         7 . The method according to  claim 1  any of  claims 1   6 , wherein the pressure of compressed air from the compressor is kept in the range of 1.2-2.0 Bars. 
     
     
         8 . A system for supplying compressed air for the operation of a moving bed filter, the system comprising:
 a compressor ( 11 ),   a conduit ( 12 ) interconnecting the compressor and the moving bed filter,   characterized in that   the compressor is a variable speed compressor.   
     
     
         9 . The system according to  claim 8 , wherein the moving bed filter comprises an air lift pump. 
     
     
         10 . The system according to  claim 8 , comprising a controller ( 14 ) and a pressure sensor ( 13 ) adapted to sense the pressure in the conduit ( 12 ), wherein the controller is adapted to control the speed of the compressor in dependence of the sensed pressure in the conduit. 
     
     
         11 . The system according to  claim 8 , wherein the compressor is a claw compressor. 
     
     
         12 . The system according to  claim 8 , wherein the compressor is devoid of lubrication in the air part. 
     
     
         13 . The system according to  claim 8 , comprising a heat exchanger ( 15 ) adapted to cool compressed air in the conduit ( 12 ). 
     
     
         14 . The system according to  claim 8 , wherein the compressor is adapted to keep the pressure in the conduit at close to a predetermined pressure in the range of 1.2-2.0 Bars. 
     
     
         15 . The system according to  claim 9 , comprising a controller ( 14 ) and a pressure sensor ( 13 ) adapted to sense the pressure in the conduit ( 12 ), wherein the controller is adapted to control the speed of the compressor in dependence of the sensed pressure in the conduit. 
     
     
         16 . The method according to  claim 2 , comprising condensing water vapor in the compressed air in an air supply system downstream of the compressor and discharging the condensed water. 
     
     
         17 . The method according to  claim 3 , comprising condensing water vapor in the compressed air in an air supply system downstream of the compressor and discharging the condensed water.