Multiple-fluid injection pump

A pump (100) for dispensing predetermined volumes of at least a first fluid (11A) and a second fluid (11B), the pump comprising:

• one or more first syringe units (55Al/r), each first syringe unit (55Al/r) comprising a first plunger (50Al/r) and a first chamber (80Al/r) within which the first plunger (50Al/r) slides;
• a first inlet channel (10A) fluidly connected to the first chamber (80Al/r) of each first syringe unit (55Al/r) and configured to receive the first fluid (11A);
• one or more first discharge ports (20Al/r) located in the first syringe unit (55Al/r) at a location different from a location of the first inlet channel (10A) in the first syringe unit (55Al/r), each first discharge port (20Al/r) fluidly connected to the first chamber (80Al/r) of a corresponding first syringe unit (55Al/r), wherein each first syringe unit (55Al/r) is operable to receive the first fluid (11A) via the first inlet channel (10A) and dispense a corresponding first predetermined volume of the first fluid (11A) via the corresponding first discharge port (20Al/r) with every cycle of the corresponding first plunger (50Al/r) sliding within the corresponding first chamber (80Al/r);
• one or more second syringe units (55Bl/r), each second syringe unit (55Bl/r) comprising a second plunger (50Bl/r) and a second chamber (80Bl/r) within which the second plunger (50Bl/r) slides;
• a second inlet channel (10B) fluidly connected to the second chamber (80Bl/r) of each second syringe unit (55Bl/r) and configured to receive the second fluid (11B);
• one or more second discharge ports (20Bl/r) located in the second syringe unit (55Bl/r) at a location different from a location of the second inlet channel (10B) in the second syringe unit (55Bl/r), each second discharge port (20Bl/r) is fluidly connected to the second chamber (80Bl/r) of a corresponding second syringe unit (55Bl/r) through a corresponding second discharge channel (70Bl/r).
• a shut-off valve (30) that is configurable at (i) a first position at which the shut-off valve (30) shuts off all of the discharge channels (70Al/r, 70Bl/r) and (ii) a second position at which the shut-off valve (30) opens all of the discharge channels (70Al/r, 7OBl/r);
• a first internal recirculating channel (90Al/r) formed in a surface of the shut off valve (30) and fluidly connecting each first discharge channel (70Al/r) to the first inlet channel (10A);
• and
• a second internal recirculating channel (90Bl/r) formed in a surface of the shut off valve (30) and fluidly connecting each second discharge channel (70Bl/r) to the second inlet channel (10B), wherein the first and second recirculating channels (90Al/r, 90Bl/r) are configured to recirculate the first and second fluids (11A, 11B) back to the first and second inlet channels (10A, 10B), respectively, when the shut-off valve (30) shuts off the discharge channels (70Al/r, 70Bl/r);
• and
• wherein each second syringe unit (55Bl/r) is operable to receive the second fluid (11B) via the second inlet channel (10B) and dispense a corresponding second predetermined volume of the second fluid (11B) via the corresponding second discharge port (20Bl/r) with every cycle of the corresponding second plunger (50Bl/r) sliding within the corresponding second chamber (80Bl/r), such that:
• the one or more first syringe units (55Al/r) and the one or more second syringe units (55Bl/r) are configured to be operated by a single actuator in parallel such that when the first plunger (50Al/r) moves to cause the first fluid (11A) to fill the first chamber (80Al/r) the second plunger (50Bl/r) moves to cause the second fluid (11B) to discharge from the second chamber (80Bl/r), and
• when the second plunger (50Bl/r) moves to cause the second fluid (11B) to fill the second chamber (80Bl/r) the first plunger (50Al/r) moves to cause the first fluid (11A) to discharge from the first chamber (80Al/r),
• the one or more first discharge ports (20Al/r) and the one or more second discharge ports (20Bl/r) are fluidly configured to deliver the first and second fluids (11A, 11B) to one or more common locations, whereby each common location receives both the first predetermined volume of the first fluid (11A) and the second predetermined volume of the second fluid (11B).