Air flow regulation in granular material delivery system

Abstract

Methods for conveying granular material from a supply to receivers that retain and dispense the material when needed by process machine include a vacuum pump, an air flow regulator connected to the vacuum pump, a first conduit connecting the receivers to the air flow regulator, and a second conduit connecting the material supply to the receivers.

The following is claimed: 
     
         1 . In a method using a vacuum pump for pneumatically conveying granular resin from a resin supply to a plurality of standalone self-contained receivers, such conveyance being powered by a single vacuum pump connected to all of the receivers via a conveyance conduit, all of the receivers being connected to the supply by a supply conduit, the improvement in controlling conveyance of granular resin from the supply to the receivers without use of central control, comprising:
 a) positioning a standalone unpowered air flow regulator immediately upstream of the vacuum pump suction inlet;   b) drawing vacuum through the air flow regulator from the supply and the receivers;   c) closing the air flow regulator upon air flow drawn by the vacuum pump exceeding a preselected value by positioning a sail portion of the regulator in the air flow entering the regulator, the sail moving a telescoping member of the regulator against a blocking plate portion of the regulator thereby blocking draw of vacuum from the supply through the receivers and halting conveyance of granular resin material; and   d) opening the air flow regulator upon air flow drawn by the vacuum pump dropping to at least the preselected value thereby permitting resumption of granular resin material conveyance.   
     
     
         2 . A method for conveying granular resin plastic material from a supply to receivers, comprising:
 a) providing a vacuum pump;   b) connecting a self-contained air flow regulator, the regulator a telescoping member movable against a transverse blocking plate interior of the regulator, the blocking plate being connected to a sail positioned within air flow within the regulator, the regulator maintaining flow drawn by the vacuum pump to a preselected value, regulator to a suction head of the vacuum pump, the flow regulator blocking flow when the preselected value is exceeded and blocking any flow if the vacuum pump fails and vacuum draw ceases;   c) connected the receivers to the air flow regulator, 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) actuating the vacuum pump, thereby drawing vacuum from the supply via a conduit to the receivers and from the receivers via a second conduit to the pump;   the vacuum drawing the granular plastic material from the supply to the receivers.   
     
     
         3 . In a method using a vacuum pump for pneumatically conveying granular resin from a resin supply to a plurality of standalone self-contained receivers, such conveyance being powered by a single vacuum pump connected to all of the receivers via a conveyance conduit, all of the receivers being connected to the supply by a supply conduit, the improvement in controlling conveyance of granular resin from the supply to the receivers without use of central control, comprising:
 a) positioning a standalone unpowered air flow regulator between each receiver and the conveyance conduit;   b) drawing vacuum through the air flow regulators from the supply and the receivers;   c) close any of the air flow regulators upon air flow drawn by the vacuum pump and experienced by a given air flow regulator exceeding a preselected value by positioning a sail portion of the regulator in the air flow entering the regulator, the sail moving a telescoping member of the regulator against a blocking plate portion of the regulator thereby blocking draw of vacuum from the supply through the receivers and halting conveyance of granular resin material; and   d) opening the air flow regulator upon air flow drawn by the vacuum pump dropping to at least the preselected value thereby permitting resumption of granular resin material conveyance through the regulator.   
     
     
         4 . The method of  claim 1  wherein the regulator comprises a telescoping member movable against a transverse blocking plate interior of the regulator, the blocking plate being connected to a sail positioned within air flow within the regulator, the regulator maintaining flow drawn by the vacuum pump to a preselected value.