Pneumatic evacuation pump

A pneumatic evacuation pump for transporting material from a material supply using air from a compressed air supply, the pneumatic evacuation pump comprising:

• a material inlet configured to receive the material from the material supply;
• an inlet valve configured to controllably restrict flow of the material through the material inlet;
• a chamber disposed downstream of the inlet valve, the chamber extending along a chamber axis between the inlet valve and a delivery valve, the delivery valve being configured to controllably restrict flow of material out of the chamber;
• a purge air injection assembly in communication with the compressed air supply and including a purge air injection line configured to direct the air from the compressed air supply to the chamber, via a purge air inlet, with a downstream component of direction relative to the chamber axis;
• a passage extending along a passage axis between the delivery valve and a discharge end, the passage axis being aligned with the chamber axis;
• a vacuum assembly including a venturi jet within a housing, the venturi jet being in communication with the compressed air supply such that, when air flows from the compressed air supply through the venturi jet, the venturi jet generates a zone of low pressure within the housing;
• a vacuum valve disposed downstream of the purge air inlet and upstream of the delivery valve, the vacuum valve configured to controllably restrict flow from the chamber to the vacuum assembly such that, when air flows from the compressed air supply through the venturi jet and the vacuum valve is open, the zone of low pressure within the housing lowers air pressure in the chamber;
• a diffuser tube disposed downstream of the venturi jet to receive exhaust air from the venturi jet;
• a flexible exhaust line disposed downstream of the diffuser tube to direct the exhaust air from the diffuser tube to the passage, via a passage inlet disposed downstream of the delivery valve, with a downstream component of direction relative to the passage axis;
• a diffuser valve disposed downstream of the diffuser tube and upstream of the passage inlet and the flexible exhaust line, the diffuser valve being configured to controllably restrict flow of the exhaust air from the venturi jet to the passage inlet via the diffuser tube;
• and
• a controller configured to coordinate a cycle of operation of the vacuum valve, diffuser valve, inlet valve, and delivery valve.