Classifying – separating – and assorting solids – Sifting – Drum sifters
Patent
1995-07-19
1997-01-14
Dayoan, D. Glenn
Classifying, separating, and assorting solids
Sifting
Drum sifters
209 22, 209397, B07B 122
Patent
active
055930433
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a rotor for mechanical air classifiers or separators of the kind utilised for handling powdered and granular materials in order to separate fine particles from coarser particles. Such classifiers comprise in general a housing with a chamber, in which a cage-like rotor is rotatably supported. The material to be classified or separated is introduced into the chamber together with air, or is introduced separately through one or more feeding points or openings. The air together with the classified part of the material is sucked in through the rotor and is from there discharged axially from the chamber.
Such classifiers are used for production and classification of fine powderous materials used as raw material for abrasives, chemicals, pharmaceuticals, toners, pigments and colourants, high technology ceramics components, coating powders, fillers, cement raw materials, micronised minerals and metallurgical powders, etc.
The rotors are either used in classifiers to separate fine particles from a previously prepared powder, or constitute parts of integrated classifiers in powder production equipment like jet mills, ball mills, vibratory mills, high pressure mills etc.
Mechanical air classifiers utilize the principles of separation by centrifugal and/or drag forces.
A main component in a such classifier is a cage-like rotor which can be rotated around an axis at any desired speed in the classification chamber. Depending on the rotation speed or the "tip speed" of the rotor surface and the drag forces and centrifugal forces acting on the mixture of air and particles, some particles, or fractions of particles, will enter the rotor and leave the system axially through the rotor as a very finally divided product. The coarser particles not captured by the rotor are removed from the classifier chamber as rejects or may alternatively be micronized further in the system.
As far as one has been able to ascertain, all types of conventional rotors are built with a plurality of longitudinal, substantially flat blades or pins, placed axially around the circumference of two or more longitudinally spaced circular plates or rings which thereby form the respective ends of the rotor unit.
The rotors may be positioned either horizontally or vertically, largely depending upon the kind of classifier involved. As mentioned, some classifiers also include micronizer equipment. Most of the known types of rotors have a uniform, cylindrical shape, but some are conically shaped and still some present a combination of cylindrical and conical shape. In any case, the openings in the rotor surface are in conventional rotors presented as longitudinal apertures having rectangular or more or less rhombic form, if a conical rotor shape is used.
In order to provide additional support for the blades of pins in the rotor, some rotors, especially larger rotors, are provided with intermediate partition blades between the end supports in order to stiffen the blades which, as will be understood, rotate at high speeds, and also to stabilize the flow of particles.
The principle aim of the present invention has been to improve the design of rotors for mechanical air/powder classifiers in order to obtain higher yields, i.e. increased specific capacities and improved classification of the material, and finer products.
A further object of the invention is to develop a rotor design with improved possibilities for varying the product finenesses, respectively the degree of classification for various sizes of classifier apparatus.
A further object of the invention is to provide a rotor design which is easier to produce and which render improved possibilities regarding variation of the desired classification.
Prior to the development of the invention, the inventor carried out various theoretical and practical studies, which terminated in the conclusion that not only the size but the configuration of the openings or apertures in the rotor constitute a critical parameter for the operation of the rotor and thereby the classification.
A pr
REFERENCES:
patent: 1592717 (1926-07-01), Breneman
patent: 1958726 (1934-05-01), Sturtevant
patent: 2006867 (1935-07-01), Mjolsness
patent: 2318249 (1943-05-01), Mjolsness
patent: 2709500 (1955-05-01), Carter
patent: 2747687 (1956-05-01), Carter
patent: 2793847 (1957-05-01), Steele
patent: 4477339 (1984-10-01), Whaley et al.
patent: 4487695 (1984-12-01), Connolly
Dayoan D. Glenn
Sinvent A/S
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