Resin delivery system with air flow regulator

1. Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, comprising:

a. vacuum pump;

b. an air flow limiter connected to a suction head of the vacuum pump, comprising:

i. a vertically oriented tube;

ii. pair of open-ended telescoping tubular internal segments within the tube, an outer tubular segment being fixed and the other being slide ably movable along the fixed segment in the axial direction;

iii. a plate extending partially across the interior of the vertically oriented tube, positioned for contacting the movable one of the telescoping tubular segments and limiting travel of the moveable telescoping tubular segment, the plate covering an open upper end of the movable telescoping tubular segment upon contact therewith;

iv. a sail positioned in the vertically oriented tube below the telescoping segments;

v. a strut connecting the sail and the moveable telescoping tubular segment;

vi. the baffle positioned to direct upward air flow within the tube into the telescoping tubular segments;

the movable telescoping tubular segment moving vertically within the tube unitarily with the sail responsive to air flow upwardly through the tube against the sail;

c. a first conduit connecting the receivers to the air flow limiter; and

d. a second conduit connecting the supply to the receivers;

whereby suction created by operation of the vacuum pump draws granular plastic resin from the supply into the receivers through the second conduit and draws air from the second conduit through the receivers, the first conduit. and the air flow limiter.

2. The air flow limiter of claim 1 wherein the tubular segments are cylindrical.

3. The air flow limiter of claim 1 wherein the surface of the plate contacted by the movable tubular segment is planar.

4. The air flow limiter of claim 3 wherein the portion of the moveable tubular segment contacting the plate surface is annular.

5. The air flow limiter of claim 1 wherein a surface of the plate contacted by the movable tubular segment is flat, the tubular segments are cylindrical, and a circular edge of the tubular segment contacting the plate surface is annular and normal to the axis of the tubular segment.

6. Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, comprising:

a. a vacuum pump;

b. air flow limiters connected to outlets of the receivers, wherein at least one of the air flow limiters is comprised of:

i. a tube;

ii. a tubular segment within the tube being movable in the axial direction;

iii. a plate extending at least partially across the interior of the tube, for contacting the movable tubular segment and defining a limit of travel of the movable tubular segment;

iv. a sail connected to the moveable tubular segment and being movable therewith within the tube;

v. a baffle, connected to and within the tube, defining a second limit of travel of the movable tubular segment, the moveable tubular segment being in sliding telescoping engagement with a tubular portion of the baffle, the baffle directing air flow within the tube into the tubular segment;

the movable tubular segment being movable unitarily with the sail in response to upward air flow through the tube contacting the sail;

c. a first conduit connecting the air flow limiters to a suction head of the vacuum pump; and

d. a second conduit connecting the supply to the receivers;

whereby suction created by operation of the vacuum pump draws granular plastic resin from the supply into the receivers through the second conduit and draws air from the second conduit through the receivers, the air flow limiters and the first conduit.