Hauni-werke Korber & Co Kg.

Korber Ag

British-american Tobacco Company Limited

Reinhard Hohm

Waldemar Wochnowski

Willi Thiele

Klaus-Georg Hackmack

Reinhard Liebe

Uwe Leckband

Manfred Lasch

Gerhard Graalmann

Ian Ernest Tatham

Hans Forster

Peter Schwarz

Manfred Muss

Herbert Schmidt

Eric H Dennis

Wilfried Muhsil

Hans-Heinrich Barth

Jurgen Koehn

Bales of compressed tobacco ribs and/or tobacco leaf laminae having a moisture content of 8-11 percent are advanced past a battery of microwave generators or through one or more electric high frequency fields to raise the temperature of particles in the bales to between 30.degree. and 90.degree. C. The bales or portions of the bales are thereupon loosened, prior to complete cooling back to starting temperature, by the pins of a conveyor which delivers the particles of loosened bales or portions of bales into the magazine of a shredding machine wherein the particles are cut. The moisture content of shreds is raised to 12-13.5 percent at which the shreds are ready for processing into smokers' products, or above 13.5 percent, for example, to between 21 and 30 percent. Such moisturizing to above the processing moisture content is or can be followed by drying of the shreds.

Method of and apparatus for manipulating bales of condensed tobacco

Apparatus for expelling moisture from a continuous stream of tobacco which passes through a conditioning zone defined by a hollow rotary drum-shaped dryer has a control unit employing a computer whose output signal is indicative of the quantity of moisture to be expelled from tobacco per unit of time during travel through the dryer in order to ensure that the final moisture content of tobacco will match a predetermined value. The signal which is generated by the computer is used to regulate a valve in a conduit connecting the conditioning zone with a source of steam. The rate of steam admission or the pressure of admitted steam increases when the quantity of moisture which is contained in tobacco entering the dryer per unit of time decreases and vice versa. This ensures that the total quantity of moisture in the conditioning zone remains at least substantially constant even though the moisture content and/or the quantity of tobacco in the stream entering the dryer varies within a wide range. The wall or walls of the dryer can be indirectly heated by steam. A threshold circuit can be installed between the adjusting device for the steam valve and the output of the computer if the conditioning zone is to receive steam only when the initial moisture content of tobacco or the quantity of tobacco which is admitted into the conditioning zone per unit of time is so low that the wall or walls of the dryer would expel excessive quantities of moisture therefrom.

Apparatus for expelling moisture from tobacco or the like

A continuous stream of moist tobacco particles is withdrawn from a magazine by a carded belt conveyor, and successive increments of the stream are weighed prior to transport past a measuring unit which ascertains the initial moisture content of successive increments of the stream. The signals which are generated by the weighing device are used to regulate the speed of the carded conveyor so as to insure that each unit length of the stream reaching the measuring unit contains identical quantities of tobacco particles per weight. The stream is thereupon transported through a moisture increasing unit wherein the stream is traversed by ascending currents of steam and wherein one or more nozzles sprinkle metered quantities of water onto successive increments of the stream. The moisture content of tobacco particles leaving the moisture increasing unit is substantially constant, and such particles thereupon enter a drying unit which includes a rotary drum-shaped conveyor wherein the particles are dried by hot air streams which flow concurrent with and counter to the direction of tobacco transport through the conveyor as well as by steam-heated coils which are installed in the interior of the conveyor to directly heat the conveyor and to directly heat the tobacco particles therein. The final moisture content of tobacco particles is measured downstream of the drying conveyor and the rate of flow of hot air which flows countercurrent to the tobacco stream and/or the rate of circulation of steam in the coils is regulated in dependency on deviations of the final moisture content from a preselected optimum value.

Method and apparatus for conditioning tobacco

The channel between the convergent tobacco compacting upper and lower chain conveyors of a tobacco shredding machine receives particles of tobacco from one or more vibrating troughs which define paths extending in parallelism with the direction of travel of particles between the chain conveyors toward the cutting station. The troughs have stepped bottom walls to effect preliminary homogenization and compacting of particles on their way toward the rear portion of the lower chain conveyor which extends rearwardly beyond the upper chain conveyor. The quantity of tobacco particles in one or more troughs is monitored by one or more photocells whose signals are utilized to vary the speed of the motor for the chain conveyors, the frequency and/or amplitude of vibratory movements of the trough or troughs and/or the rate of feed of tobacco particles to the trough or troughs when the monitored quantity deviates from a desirable range of quantities.

Method and apparatus for delivering particles of tobacco to shredding

The channel between the convergent tobacco compacting upper and lower chain conveyors of a tobacco shredding machine receives particles of tobacco from one or more vibrating troughs which define paths extending in parallelism with the direction of travel of particles between the chain conveyors toward the cutting station. The troughs can have stepped bottom walls to effect preliminary homogenization and compacting of particles on their way toward the rear portion of the lower conveyor which extends rearwardly beyond the upper conveyor. The quantity of tobacco particles in one or more troughs is monitored by photocells whose signals are utilized to vary the speed of the motor for the chain conveyors, the frequency and/or amplitude of vibratory movements of the trough or troughs and/or the rate of feed of particles to the trough or troughs when the monitored quantity deviates from a desirable range of quantities. The front portion of each trough can be vibrated in such a way that it performs recurrent movements having predominantly vertical components, and the rear portion of each trough can be vibrated to perform recurrent movements having predominantly horizontal components. This is achieved by mounting the front portion on leaf springs which make with the bottom wall of the respective trough a relatively small acute angle, and by mounting the rear portion on leaf springs which make with the bottom wall a relatively large acute angle.

The moisture content of tobacco, particularly greenleaf tobacco, is reduced to an accurately determined value by conveying a continuous tobacco stream through three successive sections of a transporting system wherein the tobacco is contacted by air currents. In accordance with a first embodiment, a relatively hot current of air is conveyed countercurrent to the direction of tobacco transport in the first section of the transporting system; in the second section, the flow of hot air is concurrent with the direction of tobacco transport; in the third section, the tobacco is contacted by relatively cool air having a relatively high moisture content. The air which is conveyed through the third section can be withdrawn from the first section, and the temperature of air in the second section is regulated as a function of deviations of moisture content of partially or completely conditioned tobacco from a desired moisture content. The temperature and moisture content of air in the third section are maintained at a constant value to bring about a hygroscopic equilibrium between air and tobacco particles in the third section. In accordance with a second embodiment, the particles of tobacco are subjected to the homogenizing action of moist air currents in the third and/or first section of the transporting system whereby the homogenizing of tobacco in the first section insures that tobacco entering the second section has a uniform moisture content and the homogenizing in third section compensates for eventual lack of uniform drying action in the second section.

A continuous stream of burley or greenleaf tobacco is transported through a first and thereupon through a second heating unit wherein the particles of tobacco are heated by ascending currents of hot air supplied at a pressure and rate such that the respective portions of the stream are fluidized. First and second detectors are provided to measure the temperature of tobacco downstream of the first and second heating units. Signals from the detectors are used to regulate the temperature of the respective air currents. The temperature of air current which is admitted into the second heating unit is further regulated in dependency on deviation of signals furnished by the detector behind the first heating unit from a reference signal denoting the desired temperature of once heated tobacco. The temperature of each current of hot air is further regulated in dependency on the monitored temperature of air which is about to enter the first and second heating units.

Method and apparatus for conditioning burley or greenleaf tobacco

The moisture content of tobacco, particularly greenleaf tobacco, is reduced to an accurately determined value by conveying a continuous tobacco stream through three successive sections of a transporting system wherein the tobacco is contacted by air currents. In accordance with a first embodiment, a relatively hot current of air is conveyed countercurrent to the direction of tobacco transport in the first section of the transporting system; in the second section, the flow of hot air is concurrent with the direction of tobacco transport; in the third section, the tobacco is contacted by relatively cool air having a relatively high moisture content. The air which is conveyed through the third section can be withdrawn from the first section, and the temperature of air in the second section is regulated as a function of deviations of moisture content of partially or completely conditioned tobacco from a desired moisture content. The temperature and moisture content of air in the third section are maintained at a constant value to bring about a hygroscopic equilibrium between air and tobacco particles in the third section. In accordance with a second embodiment, the particles of tobacco are subjected to the homogenizing action of moist air currents in the third and/or first section of the transporting system whereby the homogenizing of tobacco in the first section insures that tobacco entering the second section has a uniform moisture content and the homogenizing in third section compensates for eventual lack of uniform drying action in the section.

Tobacco particles, particularly Burley tobacco, which form a continuous stream are conditioned during transport by a series of vibratory conveyors. The foremost conveyor receives tobacco particles from a unit which contacts the particles with an atomized liquid, especially casing, and the conveyors thereupon transport the particles seriatim through preconditioning, heating, cooling and moisturizing units. The preconditioning unit has a housing consisting of one or more coiled steam pipes having orifices which discharge currents of steam against the underside of the tobacco stream at a pressure which suffices to enable the currents to form a cushion for the moving tobacco particles. The currents condense on contact with the relatively cool tobacco particles whereby the particles entrain the condensate into the heating unit wherein the particles are relieved of nitrogen and the casing is caused to penetrate into the fibrous structure of each particle with attendant roasting of the casing. The moisturizing unit may be similar to the preconditioning unit but is then further provided with one or more nozzles serving to sprinkle finely atomized water onto the particles which are supported by the cushion of steam in the housing of the moisturizing unit. The temperature of tobacco particles is measured immediately downstream of the heating unit and, if the measured temperature deviates from a desired temperature, a control circuit automatically changes the temperature and/or moisture content of hot air which is used for heating, the rate of tobacco feed to the vibratory conveyor(s) or the length of intervals of dwell of tobacco particles in the heating unit.

The particles of a continuous tobacco stream are conditioned during transport through a vibratory conveyor having a bottom wall located above a stationary chamber which receives conditioned air from one or more blowers. The bottom wall is formed with apertures through which the air passes across the tobacco stream in the form of pulsating currents which agitate the particles of the stream to insure a pronounced energy exchange between tobacco particles and air. The currents pulsate due to vibration of the bottom wall relative to the chamber, and the latter is provided with transversely extending baffles which insure that the tobacco stream is traversed by air currents having different intensities. The same result can be achieved by forming the bottom wall with larger and smaller apertures. The vibratory conveyor has two sections in the first of which the particles of tobacco are contracted by air having a temperature and moisture content corresponding to the desired temperature and moisture content of conditioned tobacco. The air which has been used for heating of tobacco in the first conveyor section is intercepted and is thereupon conditioned prior to admission into the second conveyor section.

Conditioning of tobacco

The moisture content of a stream of tobacco leaves is increased during travel through a rotary drum wherein the leaves are contacted by and exchange heat and moisture with a current of hot humid air which flows concurrent with the leaves. The moisture content of air is regulated in dependency on deviations of the final moisture content of tobacco leaves from a desired final moisture content by varying the temperature of a shower of water droplets across which the air current passes on its way into the inlet end of the drum. The temperature of air is normally constant but is changed when the initial moisture content of tobacco leaves exceeds the desired final moisture content. Tobacco leaves entering the inlet end of the drum are subjected to a preliminary moisturizing action of steam and/or atomized water, and such moisturizing action can be varied in dependency on fluctuations of initial and/or final moisture content of tobacco and/or in dependency on fluctuations in the rate of tobacco delivery into the drum. The preliminary moisturizing action requires no adjustment if the steam of tobacco leaves is equalized upstream of the drum.

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Pinneberg, Germany

Reinhard Hohm