AP42A

AP42A - "Particulate material classifier"

Info

Publication number: AP42A
Application number: APAP/P/1988/000089A
Authority: AP
Inventors: Zdravko Lajtner
Original assignee: Zdravko Lajtner
Priority date: 1987-05-22
Filing date: 1988-05-20
Publication date: 1989-05-09
Also published as: AP8800089A0; BR8802488A; ZA883545B; EP0292332A1

Abstract

The invention is concerned with the proper classification of tobacco mixtures and sets out to disclose a tobacco classifier which is able to separate tobacco mixture automatically into several constituent parts, the classifier being principally characterised by being able to perform its given task without any specific need to create within the classification chamber, a flow of air.

Description

PARTICULATE MATERIAL CLASSIFIER

This invention relates to the classification of particulate material and is particularly concerned to provide a classifier for handling the classification and separation of tobacco.

At present, it would be true to say that, to the best knowledge of the inventor, a proper system of automatic tobacco classification does not exist. The present machinery used in the industry can at best be described as tobacco separators and most operate according to the following basic principles. Separation is into only light particles and heavy particles by means of air, .namely the lights or cut lamina are lifted out of the heavies or uncut lamina and stem. The so called heavies are usually dropped out· of the separator.

In general, existing separators are loaded and off loaded by use of pneumatic conveying means and use of centrifugal type tangential separators. There are a number of disadvantages inherent In the present tobacco separators, not least . of which is the inability to separate the heavies i.e. uncut lamina and stem, into their constituent parts. Therefore, for example, the stem, even though it is a by-product of the process, tends to be carried throughout the process, thus affecting separation efficiency, power absorbed, size of equipment etc. The uncut lamina is also unneccesarily carried throughout each stage, through a number of separators, thus affecting separation efficiency, power absorbed and increasing degradation of tobacco leaf etc.

Because one or more fans are required to move air for separation and transport, vastly more power is consumed than would be required for a similar mechanical system.

It has been estimated that power consumption may be as 20 much as 14 times higher in such circumstances. There are other related problems such as for example generation of dust which then requires fi 11ratiοn or b1eeding-off , high conveying velocities of up to lOOkm/h which causes increased degradation of the leaf

AP 0 0 0 0 4 2 throughout the process, high noise levels associated with pneumatic systems, heat generated through movement of high volumes of compressed air in a closed circuit system, and not least, the high maintenance costs due to the relatively complex and expensive machinery.

A representative example of the prior art appears from

United States Patent number 4465194 of August 14, 1984 wherein a tobacco leaf separator is illustrated in the customary air separation chamber largely used in the industry.

It is a principle object of this invention to provide true classification in a graduated manner of the threshed tobacco Into its constituent parts, thus separating whole tobacco leaves, leaves with attached stem (uncut lamina), pieces of leaf with no stem (lamina) and pieces of stem with no leaf, by the use of a combination of inertia, air resistance and gravity, as opposed to the present art which simply separates heavies and lights as above described.

There are a number of significant advantages to be derived from use of the present invention ‘amongst which are the ability to remove the heavies from the process at an early stage.

The heavies will already be divided up into constituent parts i.e. uncut lamina and stem. The uncut lamina can then be sent for recutting whilst the recovered stem can be removed entirely. As a result, a dramatic reduction in the volume of tobacco being presented for further classification will occur in each subsequent classifier which should greatly increase classifier through-put efficiency, reduce degradation of the leaf and reduce both power required and maintenance of machinery.

Therefore, according to the invention, a tobacco classifier comprising in working combination, an elongate enclosed chamber having a substantially dome shaped roof; inlet means in a lower zone of the chamber adapted for the introduction of tobacco mixture into the classifier; at least one preferably paddle-type winnower associated with the inlet means and adapted to project tobacco mixture generally upwardly towards the dome of the roof in the direction of elongation; one or more open toped receiving bins located variously within the chamber in a manner and position best suited to receive the separated tobacco mixture in its constituent parts 'and scavenging means associated with said receiving bins adapted to remove the separated tobacco mixture from the chamber; the classifier being principally characterised by the ability to perform its given task without the need for any induced flow of air within the chamber.

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Also according to the invention, a tobacco classifier wherein the winnower is articulated so as to permit projection of tobacco mixture into the chamber along a higher or lower trajectory relative to the horizontal plane. In one form .of the classifier, the articulation permits also a degree of lateral projection of the tobacco mixture.

Preferably, the scavenging means comprise one or more 10 conventional conveyor belts running from a collection zone in the receiving bins, to a discharge point external to the classifier chamber.

Further according to the invention, a method of classifying tobacco mixture into its various constituent parts involves the use of one or more tobacco classifier units substantially as hereinbefore described and defined, when used in conjunction with any conventional tobacco processing plant.

The invention and the best example presently known to the inventor, will now be more fully described with reference to the accompanying drawing wherein Fig. 1 is a schematic side elevation of a tobacco ’classifier in accordance with the inyention.

Referring to Fig. 1, reference numeral 10 illustrates generally the outline of Che classifier chamber and more particularly, the dome shaped roof. Numeral 11 illustrates a paddle-type winnower having an inlet 12 for tobacco mixture . (not shown) to be introduced into the chamber 10. Numerals 13, 14, 15 and 16 generally indicate conventional conveyors leading from receiving bins 17, 18, 19 and 20 to discharge points 21, 22, 23 and 24 respectively.

Numeral 25 indicates the inlet of the next classifier in the production line process into which is directed only the separated materials requiring further processing, whilst remaining materials may be directed out of the production line at this stage.

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The classifer works without any induced airflow within the chamber 10, by relying upon the relatively low mass and poor aerodynamics of the tobacco mixture. The result

2Q is that the lighter and less aerodynamic particles will settle first and be collected into bin 17, whilst progressively heavier and more aerodynamic materials will separate out into successive bins and may then be removed by the various conveyors 13, 14, Ί 5 and 16 as required.

An essential improvement in the classifier of the invention over all prior art known to the inventor, is the removal of any specific need to create within the classification chamber any form of air stream, and this has resulted in significant savings in machinery wear and tear and in power consumption, all of which are significant factors to the users of such classifiers. It is believed that the classifier herein disclosed represents a substantial advance in the state of the art

IQ in its restricted application.

ABSTRACT OF THE DISCLOSURE

PARTICULATE MATERIAL CLASSIFIER

Claims

I. A tobacco classifier comprising in working combination, an elongate enclosed chamber having a substantially dome shaped roof; inlet means located in a lower zone of the chamber adapted for the introduction

5 of tobacco mixture into the classifier; at least one preferably paddle type winnower associated with the inlet means and adapted to project tobacco mixture generally upwardly towards the dome of the roof in the direction of elongation; one or more open toped

10 receiving bins located variously within the chamber in a manner and position best suited to receive the separated tobacco mixture in its constituent parts and scavenging means associated with said receiving bins adapted to remove the separated tobacco mixture from the

15 chamber; the classifier being principally characterised by the ability to perform its given task without the need for any induced flow of air within the chamber.

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2. A tobacco classifier as claimed in Claim 1 wherein

20 the winnower is articulated so as to permit projection of the tobacco mixture into the chamber along a lower or higher trajectory relative to the horizontal plane.
3. A tobacco classifier as claimed in Claim 1 or Claim

2 wherein the winnower is articulated in a manner so as to permit a degree of lateral projection of the tobacco mixture into the chamber.
4. A tobacco classifier as claimed in any one of the preceeding claims wherein the scavenging means comprises one or more conventional conveyor belts running from a collection zone in a receiving bin to a discharge point

10 external to the classifier chamber.
5. A method of classifying tobacco mixture into its various constituent parts involving the use of one or more tobacco classifier units substantially as claimed 15 in any of claims 1 through 4 in conjunction with any conventional tobacco processing plant.