Control means of central flow system and central flow system

Abstract

The present invention relates to a control means for a channel connectable to a central flow system configured to create an underpressure or overpressure in the channel. The control means is configured to increase or decrease the flow resistance in the channel. The control means is further configured to reduce flow resistance when the flow in said channel falls below a preset flow and to increase the flow resistance when the flow in said passage exceeds the said preset flow.

1 . Control means ( 35 ) for a channel ( 60 ) connectable to a central flow system ( 11 ) configured to create an underpressure or overpressure in said channel ( 60 ), said control means ( 35 ) being configured to increase or decrease the flow resistance in said channel ( 60 );
 characterized in that
 said control means ( 35 ) is configured to reduce flow resistance when the flow in said channel ( 60 ) drops below a preset flow and to increase the flow resistance when the flow in said channel ( 60 ) rises above said preset flow. 
   
     
     
         2 . Control means ( 35 ) of  claim 1 , wherein said control means is further configured to send a first signal ( 36 ) to increase the pressure in case the flow does not reach said preset flow despite that said control means ( 35 ) is fully open in the event said control means ( 35 ) is configured to control the flow in a pressure relief systems and to reduce the pressure in case the flow does not reach said preset flow despite that said control means ( 35 ) is fully open in the event said control means ( 35 ) is configured to control the flow in a negative pressure system. 
     
     
         3 . Control means ( 35 ) according to anyone of  claim 1  or  2 , wherein said control means ( 35 ) is further configured to receive a signal  37  indicative of the flow in said channel ( 60 ), said signal ( 37 ) being a pressure change across a restriction in said channel ( 60 ). 
     
     
         4 . Control means ( 3 ) according to anyone of  claims 1  to  3 , wherein said signal ( 37 ) indicates the flow in said channel ( 60 ). 
     
     
         5 . Control means ( 3 ) according to anyone of  claims 1  to  4 , wherein said control means ( 35 ) is further configured to send a second signal indicating the flow in said channel ( 60 ). 
     
     
         6 . Control means ( 35 ) according to anyone of  claims 1  to  5 , wherein the control means ( 35 ) is configured to control the flow in a negative pressure system. 
     
     
         7 . Control means ( 35 ) according to anyone of  claims 1  to  5 , wherein the control means ( 35 ) is configured to control the flow in an overpressure system. 
     
     
         8 . Control means ( 35 ) according to anyone of  claims 1  to  7 , wherein said control means ( 35 ) comprises a motor operated valve. 
     
     
         9 . Control means ( 35 ) according to  claim 8 , wherein said motor driven valve comprises a diaphragm valve or other valve configured to cause minimal noise. 
     
     
         10 . A central flow system ( 11 ) comprising at least a control means ( 35 ) according to anyone of  claims 1  to  9  and a central fan ( 21 ) configured to create said underpressure or overpressure in the at least one channel ( 60 ) connected to said central fan ( 21 ) and an outlet ( 41 ) connected to said channel ( 6 ). 
     
     
         11 . A central flow system ( 11 ) according to  claim 10 , wherein said central fan ( 21 ) is further configured to receive said first signal ( 37 ) and increase the pressure in the case that said central fan ( 21 ) is configured to create an excess pressure and reduce the pressure in the case said central fan ( 21 ) configured to create a vacuum. 
     
     
         12 . A central flow system ( 11 ) according to anyone of  claims 10  to  11 , wherein said central fan ( 21 ) is a subchannel blower or other suction device configured to cause minimal noise. 
     
     
         13 . A central flow system ( 11 ) according to one of  claims 11  to  12 , wherein said central fan ( 21 ) is further configured to establish said increased or decreased pressure for a certain periods of time and then return to a normal state.