Pneumatic conveying system utilizing a pressured hopper with intermittent volumetric feed control

An assembly comprising:

• a hopper;
• a pressure valve operable between an opened position to connect the hopper to a pressure source to pressurize the hopper and a closed position;
• a vent valve operable between an opened position to vent the hopper and a closed position;
• a fill valve operable between an opened position to fill the hopper with material and a closed position;
• a feed device coupled to the hopper and operable to dispense material from the hopper;
• at least one load cell coupled to the hopper;
• and
• a controller assembly including circuitry coupled to the feed device, the pressure valve, the vent valve and the fill valve and configured to open the pressure valve to the opened position during a first phase to pressurize the hopper and open the vent valve and fill valve and close the pressure valve in a second phase to depressurize and fill the hopper and the controller assembly is configured to utilize input from the at least one load cell to control the feed device in the first phase while the pressure valve is opened to pressurize the hopper and feedback from a speed sensor coupled to the feed device to control the feed device during the second phase while the pressure valve is closed.

A method comprising:

• opening a pressure valve to pressurize a hopper;
• operating a feed device to dispense material from the pressurized hopper into a pressurized convey line while the pressure valve is opened utilizing feedback from at least one load cell to increase or decrease a speed of the feed device utilizing a loss-in-weight feed control scheme during a first phase;
• detecting an input weight from the at least one load cell below a threshold weight;
• closing the pressure valve and opening a vent valve to vent the hopper;
• opening a fill valve to fill the hopper;
• and
• operating the feed device to dispense material from the hopper while the fill valve is opened to fill the hopper and the pressure valve is closed utilizing a volumetric feed rate control scheme during a second phase.