Conveyors: fluid current – With means to control conveying fluid or movement of load in... – Control of conveying fluid
Patent
1981-11-05
1984-09-25
Nase, Jeffrey V.
Conveyors: fluid current
With means to control conveying fluid or movement of load in...
Control of conveying fluid
55210, 55417, 406173, B65G 5366
Patent
active
044733267
DESCRIPTION:
BRIEF SUMMARY
This invention concerns a method of controlling the delivery conditions in a pneumatic conveyor line with an air impeller, in particular, one whose entire air conveyance system has a flat pressure/volume characteristic curve. The invention also concerns a mill pneumatic system with a regulating device, a product conveyor line, a separator, and an air impeller, for implementing such a method.
In the past three decades, mill pneumatics have nearly completely replaced the elevators previously employed for the passage lifting of intermediate milling products. Only by means of mill pneumatics can a large number of individual conveyors be installed in a manner that is particularly space-saving and adaptable to specific spatial conditions. A particularly great advantage of milling pneumatics is their relatively favorable construction cost and, also, the ease with which routes can be selected using tube switching points, rotary dispensers, etc.; they have other advantages as well, relative to other transport systems such as conveyor belts, bucket elevators, etc., despite their relativelylarge power requirements.
Many proposals have been made in the past for improving the economy of pneumatic conveyor systems, with equal or even better operating safety. In particular, in recent times the attempt has been made to obtain a so-called "dense flow conveyor", with particularly low air velocities and substantially increased product loadings. Substantial energy savings may, indeed, be achieved with the dense flow conveyor systems (such as, for example, timed pulse or stopper conveyors); however, due to their considerably greater construction costs, as well as pressures which are unusually high for mills, these systems have not gained firm acceptance into mill pneumatics, since they can only be introduced for single-line conveyance.
Now as before, mill pneumatics are usually constructed as fan pneumatics, and radial fans are generally used; axial or special blowers are employed only infrequently. For large conveyor lines and great distances, rotary reciprocating blowing engines aand, in isolated cases, screw compressors are also used.
As a rule, in mill pneumatics a number of conveyor tubes are attached to a common manifold, which is connected to the air impeller or the suction fan. Because of the large number of connections and the resulting pressure losses, an average static pressure is established that is less strongly influenced by individual passages, and adjustment of the volume of air is therefore problematic. The conveyor output of such mill pneumatics is subject to severe fluctuation, and, particularly under starting conditions, this can result in the fact that no product at all is conveyed in some of the lines.
In Swiss Pat. No. 290 764 the proposal is made for using at least two pneumatic conveyor lines, each of which is connected by way of a cleaning device to a common manifold, and each of which should have a regulating device, each of which, for its own part, controls an air volume adjusting butterfly valve. The control device should be installed between the cleaning device and the manifold, and the air volume-regulating butterfly valve, ahead of the cleaning device. The control device has the function of detecting flow fluctuations and varying the cross section of the aperture in the transport line by means of the air volume regulating valve, in order to thereby automatically ensure that the air volumes are balanced in the various transport lines. However, it has been shown that the solution proposed in Swiss Pat. No. 290 764 is not realizable, since the conveyor line cross sections employed must contain as few obstacles as possible, turns must be gentle, and tube switch points must require no sharp diversions. As a result of the additional risk of blockage due to product accumulation at the regulating valve and severe wear, this above-mentioned solution must be rejected because of practical considerations. With centrifugal force separators, which are most frequently used in mill pneumatics, the air/product m
REFERENCES:
patent: 1432111 (1922-10-01), Lewis
patent: 2724619 (1955-11-01), Berg
patent: 2826459 (1958-03-01), Oetiker
patent: 2936043 (1960-05-01), Armstrong et al.
patent: 3568847 (1971-03-01), Carr
patent: 3791413 (1974-02-01), Muller et al.
patent: 4200415 (1980-04-01), Boring
Gebruder Buhler A.G.
Nase Jeffrey V.
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