Constant discharge device in a conveyor for powdery and granular materials

A constant discharge device in a pneumatic conveyor for discharging a powdery or granular material, comprising:

• a pressure tank for storing the powdery or granular material, said pressure tank having a fluidizing apparatus for fluidizing the material;
• a conveyor pipe penetrating said tank;
• a discharge nozzle disposed in said pressure tank adjacent to said fluidizing apparatus and adapted to be connected to the conveyor pipe, said discharge nozzle having an open end;
• a discharge regulator valve disposed in said pressure tank in confronting relation to said open end of said discharge nozzle and having an outlet in an end thereof facing said discharge nozzle for ejecting a stream of air therethrough;
• a driver for adjusting said discharge regulator valve positionally with respect to said open end of said discharge nozzle, whereby the amount of the material as discharged through said discharge nozzle into the conveyor pipe can be controllably adjusted by adjusting the position of said discharge regulator valve with respect to said open end of said discharge nozzle and also by adjusting the amount of the stream of air ejected through said outlet in said discharge regulator valve;
• a booster pipe coupled to said conveyor pipe;
• a first pressure sensor for detecting the pressure in said booster pipe;
• a second pressure sensor for detecting the pressure in said pressure tank;
• and
• a differential pressure regulator controlled by signals supplied from said first and second pressure sensors, said fluidizing apparatus and said discharge regulator valve being supplied with air under pressure, the rate of flow of which is controlled by said differential pressure regulator.