Granular material delivery system with air flow limiter

1. A method for vacuum powered pneumatic conveying, without central control, granular resin plastic material from a supply to receivers, comprising:

a) connecting self-contained, self-regulating air flow limiter for regulating flow rate between no flow and a preselected rate irrespective of pressure drop across the limiter, the limiter comprising a tube, a pair of open-ended tubular segments within the tube, a fixed outer tubular segment and a segment slideably axially movable along the fixed segment, a plate extending at least partially across the tube interior, positioned for contacting and limiting travel of the moveable tubular segment, the plate covering an outlet end of the movable tubular segment upon contact therewith, and a sail connected to the moveable segment, positioned in the tube upstream of the segments, the limiter maintaining flow to a preselected value, to a suction head of a vacuum pump, the flow limiter blocking flow when the preselected value is exceeded and blocking flow if vacuum draw ceases;

c) connecting the receivers to the air flow limiter, each of the receivers being self contained without connection to or receipt of electrical signals;

d) connecting a supply of granular plastic resin material to the receivers; and

e) drawing vacuum from the supply via a conduit to the receivers and from the receivers via a second conduit to a vacuum pump suction intake, the vacuum drawing the granular plastic material from the supply to the receivers; and;

f) blocking flow when either the preselected value is exceeded or vacuum draw ceases.

2. A method for vacuum pump powered pneumatic conveying granular plastic resin material without central control from a supply to receivers comprising:

a) providing a vacuum drawing conduit connected to a suction head of a vacuum pump;

b) providing self-contained, self regulating air flow limiter for regulating flow rate between no flow and a preselected rate irrespective of pressure drop across the limiter, the limiter comprising a tube, a pair of open-ended tubular segments within the tube, a fixed outer tubular segment and a segment slideably axially movable along the fixed segment, a plate extending at least partially across the tube interior, positioned for contacting and limiting travel of the moveable tubular segment, the plate covering an outlet end of the movable tubular segment upon contact therewith, and a sail connected to the moveable segment, positioned in the tube upstream of the segments, the limiter maintaining flow to a preselected value between each receiver and the vacuum drawing conduit;

c) providing a conveying conduit between the supply and the receivers;

d) drawing vacuum from the supply via a conduit to the receivers and from the receivers via a second conduit to a vacuum pump suction intake, the vacuum drawing the granular plastic material from the supply to the receivers; and;

e) blocking flow from an individual receiver to the second conduit when either the preselected value is exceeded at the individual receiver or vacuum draw ceases.