Modular classifier

Apparatus for separating light tobacco fractions from heavier tobacco fractions comprising:

• a series of single pass, vertical lift separators serially and operably connected together, and each having a classifying chamber,
• infeed means disposed on an inlet side of each separator for projecting a stream of mixed tobacco fractions across said classifying chamber of each separator,
• means for directing a flow of separation air vertically upwardly in each classifying chamber to lift light tobacco fractions from said stream,
• the infeed means of a downstream separator oriented for receiving a portion of said projected stream directly from the infeed means of an upstream separator and for projecting said portion across the classifying chamber of said downstream separator,
• a heavy fraction removal chamber in each separator beneath said classifying chamber,
• said heavy fraction removal chamber in each separator defining an elongated, common conveyor run extending beneath the classifying chambers of all said separators,
• a single horizontally disposed conveyor in said heavy fraction removal chambers for receiving heavy fractions from each of said classifying chambers, and
• each of said separators being serially and operationally connected together along the same horizontal disposition.

Apparatus for separating tobacco lamina from tobacco stem, said apparatus comprising:

• a plurality of serially connected, single-pass vertical lift separators, each having a classifying chamber and each defining a closed loop path for flow therein of separation air, said path and flow extending through said classifying chamber,
• an infeed means having an inlet and being operatively associated with each separator for projecting a stream of mixed lamina and stem across the proximate classifying chamber such that lighter lamina can be vertically lifted and separated from said stream and heavier tobacco stem can fall out of said stream, and such that the remainder of said stream is directed into the inlet of a downstream infeed means,
• each separator including a heavier removal chamber therein to into which heavier tobacco stem parts descend, and
• a single stem removal conveyor extending through each separator's heavier stem removal chamber beneath said classifying chamber for receiving tobacco stem therefrom,
• each of said separators in the apparatus being interchangeable with each other.

A module for use in a classifying apparatus with other like modules for classifying lighter fractions from heavier fractions in a mixture thereof, said module comprising a vertical lift, single pass separator having:

• a classifying chamber,
• a heavy fraction removal chamber disposed beneath said classifying chamber for receiving a common, horizontally disposed conveyor, and having upstream and downstream ends,
• an air inlet plenum beneath said heavy fraction removal chamber,
• an inlet opening in said classifying chamber,
• an outlet opening in said classifying chamber, and
• means on the upstream and downstream ends of said heavy fraction removal chamber for connection to ends of respective heavy fraction removal chambers of adjacent separators, such that said conveyor can extend through said chambers.

Apparatus for separating tobacco lamina threshed from tobacco stem including:

• a plurality of serially interconnected single-pass vertical lift classifiers, each having a classifying chamber, infeed means for receiving mixed tobacco lamina and stem and for projecting a stream of such mix across said classifying chamber, and means for directing a flow of separation air upwardly through said stream to lift lighter lamina from heavier stem,
• a first common conveyor extending horizontally beneath the classifying chambers of the plurality of classifiers for receiving tobacco stem, and
• said infeed means having an inlet disposed to receive a portion of said projected stream directly from an upstream classifier which portion is neither lifted from said projected stream nor dropped onto said conveyor,
• said classifiers being interchangeable, one with another, and being oriented along the same horizontal disposition.

A method of separating heavy and light material fractions conveyed in a mixed stream of both fractions of material, said method comprising the steps of:

• projecting a stream of mixed material progressively across separation chambers of a plurality of modular separators;
• blowing air upwardly in each chamber to lift away lighter fractions of material;
• receiving heavier fall-out fractions of material in a lower portion of each chamber on a common conveyor and conveying such heavier portion horizontally into successive downstream separators;
• receiving a mixed stream of material, which has not been lifted away or fallen out, at a downstream side of each said chamber at a vertical disposition substantively horizontally level with the location from which said mixed stream was projected and except for the last downstream separation, projecting said mixed stream across the separation chamber of the next downstream separator for further separation.

A method of separating from a mixed stream of tobacco the lighter fractions of tobacco from the heavier fractions of tobacco in a modular classifier comprising a series of side-by-side operationally interconnected separation chambers, each method including, in each upstream chamber:

• projecting said stream across said chamber;
• dividing said mixed stream into three components including a lighter fraction component, and a heavy fraction component;
• lifting away said lighter fractions from each chamber by blowing said lighter fractions upwardly;
• conveying heavier fractions falling out of said stream horizontally into a downstream chamber on a common conveyor;
• and
• receiving a mixed stream of fractions neither lifted away nor fallen out from said projected stream in said chamber, and projecting said received stream across a downstream separation chamber.

Classifying apparatus for separating heaving and light material fractions conveyed in a mixed stream of material, said apparatus comprising:

• a plurality of single pass, vertical lift, serially oriented classifier modules, each comprising an upper classifying chamber, a heavy fraction removal chamber, a lower air inlet plenum, an inlet opening on one side of said classifying chamber, an outlet opening on another side of said classifying chamber, and a light fraction outlet at an upper portion of said classifying chamber;
• each said module further including an infeed means operably disposed proximate each respective classifying chamber for receiving mixed material for classification and for projecting a stream of said mixed material across a respective classifying chamber in a single pass for upward separation of lighter fractions from heavier fractions,
• one of said infeed means being operatively connected between an opening of an upstream module and an opening of a downstream module for receiving mixed material from an upstream module and for projecting a stream of mixed material across the chamber of a downstream module,
• said heavy fraction removal chamber of each module being operatively connected to the heavy fraction removal chamber of adjacent modules,
• a horizontally disposed heavy fraction removal conveyor extending through said connected heavy fraction removal chambers, and
• means in said lower air inlet plenum for directing a flow of mixture separation air substantially vertically upwardly and perpendicularly through said conveyor and through said classifying chamber of each module,
• said modules each being interchangeable with an operably connectable to other like modules.