Conveyors: fluid current – Having means to introduce booster fluid into conveyor – Plural booster inputs
Patent
1982-02-11
1985-01-01
Nase, Jeffrey V.
Conveyors: fluid current
Having means to introduce booster fluid into conveyor
Plural booster inputs
406195, B65G 5316
Patent
active
044914423
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method and device for pneumatic feeding of powdery and/or granulated bulk materials, of heavy flowing and/or sticky, of abrasive, sensitive and/or moist materials in a tubular feeding line by means of a device, the feeding line of which is supplied with carrier gas along its length from a plurality of gas lines discharging into the feeding line and spaced consecutively apart from each other. It is therefore intended to provide a very advantageous, so-called seal flow feeding in respect of feeding capacity and economic efficiency (comparably lower energy requirements) in comparison with other pneumatic feeding methods.
A method of this type is known, for example, from DE-PS No. 26 57 677. This known method does, however, have the disadvantage that the carrier gas from the pressure gas source, which supplies the gas lines discharging into the feeding line, will, when a plug forms in the feeding line, flow into the feeding line essentially through that gas line which offers least resistance. This leads to an uneven supply of gas into the feeding line and there is also no chance of the plug in the feeding line being dissolved.
In the case of another known feeding device (DE-PS No. 449 393) having a gas supply line adjacent to the feeding line valves are disposed in the gas lines running from the gas supply line to the feeding line, these valves automatically opening and closing again to eliminate any plugs formed in the feeding line, i.e. with this known feeding device the gas lines discharging into the feeding line are normally closed. The disadvantage of this known feeding device is therefore not only that it does not work in accordance with the seal flow supply method mentioned but that the pressure-responsive controllable valves in the gas lines require considerable resources and are also a source of possible interruptions.
The object of the present invention was therefore to develop a method of the type mentioned at the beginning such that even if plugs are formed in the feeding line selected amounts of gas may reach the feeding line through the individual gas lines and that plugs can be dissolved.
This object may be solved according to the invention in that the velocity of the gas in each of the gas lines is increased to the velocity of sound at a point before the opening into the feeding line and likewise decreased again before the opening. By generating the velocity of sound at a point in each of the gas lines the amount of gas flowing through each gas line per unit of time will be independent of the pressure ratio in the feeding line; decreasing the velocity of the gas before the opening into the feeding line prevents the wall of the feeding line in the area where the gas lines open into it being subjected to intense erosive abrasion. The method according to the invention may be carried out by a particularly simple device; based on a feeding device having a tubular feeding line, into which a plurality of gas lines open, these being spaced consecutively apart from each other and fed from at least one pressure gas source, such a device is designed according to the invention such that each gas line has at a distance from its opening into the feeding line a cross-sectional constriction, the throughflow cross section widening again between this constriction and this opening, and that the pressure of the gas before the cross-sectional constriction is in over-critical ratio to the pressure in the feeding line. According to the invention no movable parts are required in the gas lines, in contrast to the known feeding device according to DE-PS No. 449 393, and the cross-sectional constriction may have the form of a simple apertured diaphragm.
In the case of pneumatic feeding devices having a plurality of feeding lines fed by one common compressed air source it is already known (DE-PS No. 1 121 544) to have one single gas line leading from the compressed air source to each feeding line and to have a nozzle disposed in this line for generating the velocity of sound. With the known cons
REFERENCES:
patent: 2874999 (1959-02-01), Lofgren
patent: 2897005 (1959-07-01), Wiltse
patent: 3206255 (1965-09-01), Gray
patent: 3413038 (1968-11-01), Frazier
patent: 3537755 (1970-11-01), Schmidt
patent: 3591238 (1971-07-01), Titus
patent: 3837540 (1974-09-01), Wagener
patent: 3876259 (1975-04-01), Gunderson
patent: 4025121 (1977-05-01), Kleysteuber et al.
Hanggi Manfred
Stelter Jurgen
Durr Automation + Fordertechnik GmbH
Nase Jeffrey V.
Williams L. E.
LandOfFree
Method and device for pneumatic feeding of materials does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for pneumatic feeding of materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for pneumatic feeding of materials will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-576131