Pneumatic material delivery system with air flow limiting

Abstract

Apparatus 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 limiter connected to the vacuum pump, a first conduit connecting the receivers to the air flow limiter, and a second conduit connecting the material supply to the receivers.

The following is claimed: 
     
         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) a vacuum pump;   b) an air flow limiter connected to a suction head of the vacuum pump;   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 . Apparatus of  claim 1  wherein the air flow limiter further comprises:
 a) a tube; 
 b) a pair of open-ended tubular segments within the tube, an outer tubular segment being fixed and the other being slideably axially movable along the fixed segment; 
 c) a plate extending partially across the interior of the tube, 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; 
 d) a sail connected to the moveable segment, positioned in the tube upstream of the segments. 
 
     
     
         3 . Apparatus of  claim 2  wherein the tubular segments are telescoping. 
     
     
         4 . 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;   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.   
     
     
         5 . The apparatus of  claim 4  wherein at least one of the air flow limiters consists of:
 a) a tube; 
 b) a pair of open-ended tubular segments within the tube, an outer tubular segment being fixed and the other being slideably axially movable along the fixed segment; 
 c) a plate extending partially across the interior of the tube, 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; 
 d) a sail connected to the moveable segment, positioned in the tube upstream of the segments. 
 
     
     
         6 . Apparatus of  claim 1  wherein the air flow limiter comprises:
 a. a tube; 
 b. a valve within and connected to the tube; and 
 c. a baffle located within and connected to the tube, positioned to direct air flow within the tube against the valve. 
 
     
     
         7 . Apparatus of  claim 6  wherein the valve comprises a pair of telescoping tubular segments. 
     
     
         8 . Apparatus of  claim 7  wherein the outer one of the telescoping tubular segments is fixed by and the inner one of the telescoping tubular segments is slidably moveable along the fixed segment in the axial direction with the tube. 
     
     
         9 . Apparatus of  claim 8  wherein the valve further comprises a plate extending partially across the interior of the vertically oriented tube, being connected to the tube and positioned for contacting a moveable one of the telescoping tubular segments. 
     
     
         10 . Apparatus of  claim 9  wherein the valve further comprises a sail within the vertically oriented tube, connected to the moveable one of the telescoping tubular segments. 
     
     
         11 . Apparatus of  claim 4  wherein the air flow limiter further comprises:
 a. a tube; and 
 b. a valve within and connected to the tube; and a baffle located within and connected to the tube, positioned to direct air flow within the tube against the valve. 
 
     
     
         12 . Apparatus of  claim 11  wherein the valve comprises a pair of telescoping tubular segments. 
     
     
         13 . Apparatus of  claim 12  wherein the outer one of the telescoping tubular segments is fixed and the inner one of the telescoping tubular segments is slidably moveable along the fixed segment in the axial direction with the tube. 
     
     
         14 . Apparatus of  claim 13  wherein the valve further comprises a plate extending partially across the interior of the vertically oriented tube, being connected to the tale and positioned for contacting a moveable one of the telescoping tubular segments. 
     
     
         15 . Apparatus of  claim 14  wherein the valve further comprises a sail within the vertically oriented tube, connected to the moveable one of the telescoping tubular segments. 
     
     
         16 . Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, consisting of:
 a) a vacuum pump;   b) an air flow limiter connected to a suction head of the vacuum pump;   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.   
     
     
         17 . Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, consisting of:
 a) a vacuum pump;   b) air flow limiters connected to outlets of the receivers;   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.   
     
     
         18 . Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, consisting essentially of:
 a) a vacuum pump;   b) an air flow limiter connected to a suction head of the vacuum pump;   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.   
     
     
         19 . Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, consisting essentially of:
 a) a vacuum pump;   b) air flow limiters connected to outlets of the receivers;   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.   
     
     
         20 . 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) an air flow limiter connected to a suction head of the vacuum pump; the air flow limiter comprising:
 i) a tube; 
 ii) a pair of open-ended tubular segments within the tube, an outer tubular segment being fixed and the other being slideably axially movable along the fixed segment; 
 iii) a plate extending partially across the interior of the tube, 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; 
 iv) a sail connected to the moveable segment, positioned in the tube upstream of the segments. 
   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.   
     
     
         21 . Apparatus for conveying granular plastic resin from a supply to receivers that retain and dispense the resin when needed by a process machine, consisting of:
 a) a vacuum pump;   b) an air flow limiter connected to a suction head of the vacuum pump; the air flow limiter consisting of:
 i) a tube; 
 ii) a pair of open-ended tubular segments within the tube, an outer tubular segment being fixed and the other being slideably axially movable along the fixed segment; 
 iii) a plate extending partially across the interior of the tube, 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; 
 iv) a sail connected to the moveable segment, positioned in the tube upstream of the segments. 
   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.