Blenders

Abstract

The invention relates to a material transfer device ( 1 ), in particular for use with blenders associated with a material processing device such as a plastics extruding device. The material transfer device ( 1 ) can be used for controlling delivery of measured amounts of particulate material to or from a weigh hopper, or for mixing materials in a mixing chamber of the blender. The material transfer device ( 1 ) includes a pipe ( 2 ) defining a material delivery path. The pipe ( 2 ) has a material inlet ( 4 ) and a material outlet ( 5 ). An air inlet manifold ( 10 ) encircling the pipe ( 2 ) is connected by an air supply line ( 14 ) to a pressurised air supply. Air outlets ( 12 ) of the manifold ( 10 ) direct an air stream towards the outlet ( 5 ) of the pipe ( 2 ) to draw material through the pipe ( 2 ) from a hopper ( 6 ) of particulate material ( 7 ), the pipe inlet ( 4 ) being located within the hopper ( 6 ). An air inlet valve ( 16 ) in the air supply line ( 14 ) is connected to a controller ( 22 ) which is operable to open an shut the valve ( 16 ) for pulsing the gas steam to control the amount of material delivered through the pipe ( 2 ).

1 . A material transfer device, including: 
 a pipe defining a material delivery path,    the pipe having a material inlet and a material discharge outlet,    means for delivering a gas steam along the material delivery path directed towards the outlet, and    means for controlling the gas stream for controlling delivery of material through the pipe.    
     
     
         2 . A material transfer device as claimed in  claim 1  wherein said control means is operable for pulsing the gas stream.  
     
     
         3 . A material transfer device as claimed in  claim 1  wherein said control means is a gas inlet valve connected to a controller which is operable to open and shut the valve for desired time periods.  
     
     
         4 . A material transfer device as claimed in  claim 1  wherein the gas control means includes means for regulating the pressure of the gas.  
     
     
         5 . A material transfer device as claimed in  claim 3  wherein said means comprises a pressure regulator mounted upstream of the gas inlet valve.  
     
     
         6 . A material transfer device as claimed in  claim 1  wherein the gas control means includes means for regulating gas flow rate.  
     
     
         7 . A material transfer device as claimed in  claim 1  including means for delivering an annular gas steam into the pipe.  
     
     
         8 . A material transfer device as claimed in  claim 7  wherein the means for delivering an annular gas stream into the pipe comprises a gas inlet manifold extending about the pipe having an inlet for connection to a pressurised gas supply and an outlet communicating with the material delivery path.  
     
     
         9 . A material transfer device as claimed in  claim 8  wherein the outlet includes a number of circumferentially spaced-apart outlet openings extending through the pipe and arranged to direct gas towards the outlet of the pipe.  
     
     
         10 . A material transfer device as claimed in  claim 8  wherein the outlet of the means for delivering the annular gas stream into the pipe is located intermediate the ends of the pipe for delivering the gas stream into the pipe directed twos the outlet of the pipe.  
     
     
         11 . A material transfer device as claimed in  claim 1  wherein the means for delivering a gas stream along the material delivery path has a gas outlet angled relative to the pipe to diet a gas stream into the pipe towards the outlet of the pipe.  
     
     
         12 . A material transfer device as claimed in  claim 1  in combination with a weighing device with either the inlet or the outlet of the pipe being connected to an outlet or an inlet respectively of the weighing device.  
     
     
         13 . A mixing device incorporating a material transfer device and an associated nag chamber, a material transfer device including a pipe defining a material delivery path be pipe having a material inlet and a material discharge outlet, means for delivering a gas steam along the material delivery path directed towards the outlet to deliver material between the inlet and the outlet, the outlet of the pipe being located adjacent and spaced-apart from a deflector baffle within the mixing chamber for scattering material discharge from the pipe within the nixing chamber.  
     
     
         14 . A nixing device as claimed in  claim 13  including a mixing chamber with the material transfer device having an inlet of the pipe located adjacent a bottom of the mixing chamber and an outlet of the pipe located above the inlet for directing material from the pipe outlet against a deflector baffle for discharge into the mixing chamber.  
     
     
         15 . A mixing device as claimed in  claim 13  wherein the material transfer device is located within the mixing chamber.  
     
     
         16 . A mixing device as claimed in  claim 15  wherein the pipe of the material transfer device is mounted centrally in an upright orientation within the mixing chamber.  
     
     
         17 . A mixing device as claimed in  claim 15  wherein the deflector baffle is of arcuate shape for deflecting material discharged from the outlet of the pipe outwardly and downwardly towards the inlet of the pipe.  
     
     
         18 . A blending apparatus for mixing particulate materials prior to discharge into a process line incorporating a mixing device as claimed in  claim 13 , the blending apparatus including a mixing chamber, mixing means for mixing additive materials within the mixing chamber, characterised in that said mixing means comprises the material transfer device having the inlet of the material transfer device communicating with a bottom of the mixing chamber and the outlet of the material transfer device communicating with the top of the mixing chamber.  
     
     
         19 . A blending apparatus as claimed in  claim 18  further including a weigh hopper having an outlet arranged to discharge material from the weigh hopper to the mixing chamber, at least one raw material supply bin, a material transfer device mounted at an outlet of the material supply bin being operatively connected to a controller to regulate discharge of material from the bin to the weigh hopper or the mixing chamber.  
     
     
         20 . A blending apparatus as including: 
 a mixing chamber, the mixing chamber having an inlet for reception of a batch of additive materials to be mixed and a blended material outlet,    a lower portion of the mixing chamber tapering inwardly and downwardly towards a bottom of the mixing chamber which forms a trough, the blended material outlet being located in the trough at the bottom of the mixing chamber,    mixing means for mixing materials in the mixing chamber,    a level sensor mounted within the mixing chamber, the level sensor being connected to a controller which is operable to regulate the supply of fresh materials to the mixing chamber for mixing, said controller being operable to deliver a batch of additive materials into the mixing chamber when the level of material within the mixing chamber drops to the level sensor,    the mixing means comprising at least one material transfer device mounted on a side wall of the mixing chamber, said material transfer device including a pipe defining a material delivery path, the pipe having a material inlet and a material discharge outlet, means for delivering a gas stream along the material delivery path directed towards the outlet to deliver material between the inlet and the outlet, the inlet of the material transfer device communicating with a bottom of the mixing chamber and the outlet of the material transfer device communicating with a top of the mixing chamber.    
     
     
         21 . A blending apparatus incorporating the material transfer device as claimed in  claim 1 , said blending apparatus for controlled delivery of blend additives to a material processing device, including a primary additive feed hopper and at least one secondary additive feed hopper communicating with an additives discharge chute having an upper inlet end and a lower outlet end for connection to an additive inlet of the material processing device, the or each secondary additive feed hopper having an associated feeding means for delivery of material from the secondary additive feed hopper to the additives discharge chute, characterised in that said feeding means comprises the material transfer device, an inlet of the material transfer device being connected to the secondary additive feed hopper and the outlet of the material transfer device communicating with an interior of the additives discharge chute.  
     
     
         22 . A blending apparatus for controlled delivery of blend additives to a material processing device, including: 
 a primary additive feed hopper,    at least one secondary additive feed hopper,    an additive discharge chute having an outset for connection to the material processing device,    the primary additive feed hopper being mounted above the additive discharge chute for continuous gravity feed of additive material thereto,    a secondary feeding means being connected between each secondary feed hopper and the additives discharge chute for delivery of feed additives from the secondary feed hopper to the additives discharge chute,    means for sensing the throughput of material in the material processing device,    means for sensing the discharge of additives from the feed hoppers,    a controller adapted to be connected to the means for sensing the throughput of the material processing device and to the means for sensing the discharge of additives from the feed hoppers,    the controller including means for regulating the throughput of material through the material processing device in response to the sensed discharge of material from the feed hoppers,    the secondary feeding means comprising a material transfer device including a pipe defining a material delivery path, the pipe having a material inlet and a material discharge outlet means for delivery of a gas stream along the material delivery path directed towards the outlet to deliver material between the inlet and the outlet the inlet being connected to the secondary feed hopper and the outlet discharging into the additives discharge chute.    
     
     
         23 . A material transfer device including: 
 a pipe defining a material delivery pat, the pipe having a material inlet and a material discharge outlet, means for delivering a gas stream along the material delivery path directed towards the outlet, and means for pulsing the gas stream for controlling delivery of material through the pipe.    
     
     
         24 . A material transfer device including: 
 a pipe defining a material delivery path, the pipe having a material inlet and a material discharge outlet, means for delivering a gas stream along the material delivery path directed tows the outlet, and means for pulsing the gas stream for controlling delivery of material through the pipe,    said pulsing means comprising a gas inlet valve mounted in a gas supply line having an inlet for connection to a pressurised gas supply source and an outlet connected to the pipe for delivery of gas into the pipe, means for opening and closing said gas inlet valve, said means being connected to a controller which is operable to open and shut the gas inlet valve for desired time periods for pulsing the gas stream delivered through the gas supply line.    
     
     
         25 . A material transfer device including: 
 a pipe defining a material delivery path, the pipe having a material inlet and a material discharge outlet, means for delivering a gas stream along the material delivery path directed towards the outlet, and means for pulsing the gas stream for controlling delivery of material through the pipe,    said pulsing means comprising a gas inlet valve mounted in a gas supply fine having an inlet for connection to a pressurised gas supply source and an outlet connected to the pipe for delivery of gas into the pipe, means for opening and closing said gas inlet valve, said means being connected to a controller which is operable to open and shut the gas inlet valve for desired time periods for pulsing the gas stream delivered through the gas supply line,    the gas supply line being connected to a gas inlet manifold mounted around the pipe and having a plurality of circumferentially spaced-apart outlet openings extending through the pipe and arranged to direct gas towards the outlet of the pipe and a pressure regulator being mounted in the gas supply line upstream of the gas inlet valve.    
     
     
         26 . A material transfer device in combination with a weighing device, the material transfer device including a pipe defining a material delivery path, the pipe having a material inlet and a material discharge outlet, means for delivering a gas stream along the material delivery path diet towards the outlet to deliver material between the inlet and the outlet, the weighing device comprising a weigh hopper having a material inlet and a material outlet, either the inlet or the outlet of the pipe of the material transfer device being connected to an outlet or an inlet respectively of the weighing device, a controller which is operable for pulsing the gas stream, said controller being operable to regulate pulsing of the gas stream to control the amount of material delivered out of or into respectively the weigh hopper.