Patent ID: 7997556

Claim:
A finely adjustable firing valve for rapidly discharging compressed air or compressed gas, for the purpose of generating a pressure wave in silos or containers of granular materials, comprising a pneumatic main valve ( 1 ) presenting a valve body ( 2 ) with an inlet ( 3 ) and a discharge ( 5 ) connected together via a main actuation chamber ( 8 ), a main access ( 26 ) connecting the inlet ( 3 ) to the main actuation chamber ( 8 ), and a main port ( 6 ) connecting the main actuation chamber ( 8 ) to the discharge ( 5 ), said main valve ( 1 ) also comprising a main valving element ( 7 ) arranged to move within said main actuation chamber ( 8 ) to alternately connect the inlet ( 3 ) to the discharge ( 5 ) or the inlet ( 3 ) to a first connection conduit ( 11 ) which opens into the main actuation chamber ( 8 ), said firing valve further comprising a pneumatic secondary valve ( 9 ), arranged to control the main valve ( 1 ) by acting on said main valving element ( 7 ), and comprising a secondary actuation chamber ( 15 ) of volume less than the main actuation chamber ( 8 ), and connected by said first connection conduit ( 11 ) to the main actuation chamber ( 8 ), a secondary discharge ( 12 ) connected to the secondary actuation chamber ( 15 ), a secondary access ( 10 ) connecting the first connection conduit ( 11 ) to the secondary actuation chamber ( 15 ), and a secondary port ( 13 ) connecting the secondary actuation chamber ( 15 ) to the secondary discharge ( 12 ), said secondary valve ( 9 ) also comprising a secondary valving element ( 14 ) arranged to move within said secondary actuation chamber ( 15 ) to alternately connect the first connection conduit ( 11 ) to the secondary discharge ( 12 ) or the first connection conduit ( 11 ) to a second connection conduit ( 18 ) which opens into the secondary actuation chamber ( 15 ), said firing valve further comprising a pilot valve ( 16 ), arranged to control the secondary valve ( 9 ) by acting on said secondary valving element ( 14 ) via said connection conduit ( 18 ), characterised in that said main valving element ( 7 ) is of membrane type, it is fixed to the centre of the main actuation chamber ( 8 ), and it can move within the main actuation chamber ( 8 ) by rising and falling peripherally.