Patent Application
20080038071
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
In operation, when the air stream AS enters the separation chamber 3, it expands and slows dramatically, and the pneumatic conveyor 1 is configured so that the carried particles should drop out of the slowed air stream AS into the auger intake opening 11 and out through the auger discharge conveyor 9, and the air stream AS passes to the intake of the fan 15 and out through the exhaust 17. When conveying light weight particles P, as illustrated in
The present invention therefore provides, in one embodiment as illustrated in
As illustrated in
The kit apparatus 20 also comprises a screen 27 attachable to cover a second portion 11B of the auger intake opening 11 such that the air stream AS flows from the input port 5 into the first portion 11A of the auger intake opening 11 and then flows out of the second portion 11B of the auger intake opening 11 through the screen 27 into the separation chamber 3 and out through the fan 15. The holes 26 in the screen 27, as illustrated in
The screen is attached in proximity to outer edges of the auger flight 29 of the discharge auger conveyor 9 such that particles P carried in the air stream AS are scraped off the screen 27 by the auger flight 29, and thus prevented from being held against the screen 27 and blocking the air stream AS. In the illustrated embodiment the screen 27 conveniently forms a semi-cylindrical cover over the second portion 11A of the auger intake opening 11, the semi-cylindrical cover having a radius substantially the same as that of the auger flight 29 such that the two can be placed in close proximity.
The auger intake opening 11 comprises an opening in an auger tube 31 enclosing the auger flight 29 such that the auger intake opening 11 has a lower end adjacent a bottom end of the auger flight 29 and an upper end. The first portion 11A of the auger intake opening 11 is adjacent to the lower end of the auger intake opening 11 such that particles P in the air stream AS first flow into the lower end of the intake opening 11, and then are conveyed by rotation of the auger flight 29 and by flow of the air stream AS up past the screen 27 covering the second portion 11B in the upper end of the auger intake opening 11, where the air stream AS exits into the separation chamber 3 while the particles P are prevented from doing so by the screen 27, and so the particles P continue up the discharge auger conveyor 9.
In the illustrated embodiment the housing 21 is attached to the wall 23 of the separation chamber 3 by attachment of a top flange 35 to the shroud 25 such that a channel 37 from the input port 5 to the first portion 11A of the auger intake opening 11 is formed between the housing 21 and the wall 23 of the separation chamber 3. Side flanges 37 adjacent to the screen 27 can be attached with screws or the like to adjacent portions of the chamber 3. The illustrated kit apparatus 20 is thus configured as a single housing and screen assembly 40 that is relatively simple and quick to install, and that can likewise be removed to allow conventional operation of the pneumatic conveyor with heavier particles. The illustrated kit apparatus 20 is designed to fit the illustrated pneumatic conveyor 1. Those skilled in the art will readily adapt the kit apparatus to suit other designs and configurations of pneumatic conveyors.
The invention thus provides a method of conveying light weight particles P through a pneumatic conveyor 1 by directing the air stream AS through a housing 21 from the input port 5 of the separation chamber 3 to a first portion 11A of the auger intake opening 11, and covering the second portion 11B of the auger intake opening 11 with a screen 21 such that the air stream AS flows from the input port 5 into the first portion 11A of the auger intake opening 11 and flows out of the second portion 11B of the auger intake opening 11 through the screen 27 into the separation chamber 3, and such that particles P carried in the air stream AS are maintained in the auger discharge conveyor 9.
A vacuum port 111 is located in the auger tube 131 between the input port 105 and the discharge end 113, and a screen 127 covering the vacuum port 111. The screen 127 is configured such that outer edges of the auger flight 129 are located in proximity to the screen 127.
A suction device 115 is connected to the vacuum port 111 and is operative to create an air stream AS flowing from the intake end of the vacuum duct 107 through the auger input port 105 into the auger tube 131, and out through the screen and the vacuum port. In the illustrated apparatus 100 the vacuum port 111 is adjacent to the input port 105 where the distance traveled by the air stream AS through the tube 131 is minimized.
In the illustrated embodiment the screen 127 forms a semi-cylindrical cover over the vacuum port 111, the semi-cylindrical cover having a radius substantially the same as that of the auger flight 129. Thus the particles P carried in the air stream AS are blocked by the screen 127, and are scraped off the screen 127 by the auger flight 129 and conveyed up the auger discharge conveyor 109 to the discharge end 113.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
