US2799278A - Method of treating tobacco - Google Patents

Description

July 16, 1957 Filed Aug. 26. 1954 S. BOGATY METHOD OF TREATING TOBACCO s Shets-Sheet 1 ATTORNEYS July 16, 1957 s. BOGATY' 2,799,278

METHOD OF TREATING TdBAcco' Filed Aug. 26, 1954 s Sheets-Sheet 2 JTTOR NE Y5 July 16, 1957 Filed Aug. 26, 1954 S. BOGATY METHOD OF TREATING TOBACCO 3 Sheets-Sheet 3 BY JIM ATTORNEYS METHOD OF TREATING TOBACCO Stanislaus Bogaty, Philadelphia, Pa., assignor to Proctor & Schwartz, Inc., Philadelphia, Pa., a corporation of Pennsylvania Application August 26, 1954, Serial No. 452,270

2 Claims. (Cl. 131144) This invention pertains to the processing of tobacco strips to provide smoking tobacco. It is concerned specifically with the drying and cutting of the strips, and with the related steps by which the moisture content is maintained at a substantially uniform point in the finished product.

In a typical process involving prior art processing, the dipped tobacco strips are passed continuously on a single conveyor consecutively through drying, cooling and ordering chambers. In the drying chamber, they are subjected to the drying effect of the circulation of heated air, the drying being controlled to reduce the moisture content to approximately 8 to on a bone-dry basis at the time the product leaves the dryer. It is then cooled in a second chamber to about room temperature and passed to and through a third chamber where steam is injected during continuous passage of the material, to restore its average moisture content to approximately 18-24%. It is then subjected to a bulking operation to obtain substantially uniform distribution of the moisture, cut to the desired particle size, and finally dried further to the point required for smoking tobacco.

While this prior art process provides a reasonably satisfactory product, this is attained at the expense of a rather costly sequence of operating steps, and requires a considerable amount of costly equipment.

A primary object of this invention has been to provide an operation which is both more economical than that described above, because it reduces the amount of equipment and number of operating steps, and more effective, because it produces a better controlled and more uniformly dried product.

A further object has beento simplify the process in such a way that the ordering step may be entirely eliminated, along with the expensive, non-corrosive equipment required for this step.

A further object has been to provide a process in which the cost of the initial drying step may be greatly reduced, by making it much less drastic and time consuming.

,These objects have been achieved by providing anew sequence of operations in which the initial drying step is terminated at a point where much more moisture is retained than in the process discussed above. The partially dried strips are then bulked to obtain substantially uniform distribution of the moisture still retained, and the final drying step follows this bulking step, with an intervening cutting step interposed if the tobacco is to be cut into particles. It will thus be seen that the sequence of removing moisture in the final drastic treatment of the first drying step and then restoring it in the ordering step is eliminated, and that it becomes unnecessary to provide the expensive ordering step and equipment. Since the bulking operation redistributes the moisture at a level only a little above the ultimate moisture content desired, this contributes to uniformity in the product obtained after further final drying, particularly when this is performed on the pervious bed of material obtained from an intervening cutting operation.

Further objects and advantages, and the manner in which the various objects are attained, will be evident from reading of the following specification in the light of the attached drawing, in which the various views are somewhat schematic, illustrating apparatus for practice of the successive steps of the invention, and,

Figure 1 is a plan view of apparatus for performing the opening, dipping and first drying steps;

Figure 2 is a side elevation, partly in section, of the apparatus of Figure l;

Figure 3 is a plan view of the bulk, cuttmg and classifying apparatus;

Figure 4 is a side elevation corresponding to Figure 3;

Figure 5 is a plan view of the final dryer; and,

Figure 6 is a side elevation corresponding to Figure 5.

Referring to the drawing by reference characters, it will be seen that Figures 1 and 2 illustrate a sequence in which the overlapped strips from the hogshead of tobacco are fed upwardly by an inclined feed apron 10 into a moistening and opening cylinder 11, where they are loosened and softened by the combined effects of the pins 12 of the rotating cylinder and of steam injected through inlet 13, as they move downwardly to the outlet end of this cylinder. From the lower end of cylinder 11, the loosened tobacco strips are passed by a feed apron 14 at a controlled rate into the forward end of a dipping tank 15, through which they are passed by the circulation of the flavoring solution as indicated by the arrows in Figure 1, as produced by the circulating paddle 16. The tobacco is forced under immersion roller 17 as it passes through this tank, and it is carried forwardly and upwardly from the forward end of the tank by pins or spikes on conveyor belt 18, the tobacco being carried on the underside, and supported by a perforated plate as it moves upwardly from the tank. From conveyor 18, it is passed through a wringer 19 and thence to a crossconveyor 20 which delivers it to a wiper conveyor 21, by which it is passed into the automatic feed 22 of a first stage dryer 23, and thence continuously through the dryer at a controlled rate on conveyor 24 which may comprise a number of hingedly connected wire mesh sections mounted on a driving chain.

The sequence of steps so far described is no part of the present invention, as these steps are common to this. invention and the prior art, and are here discussed merely as a back ground for the invention. Insofar as discussion of apparatus is concerned, it must be understood that this may be varied considerably, both for practice of these background steps and for practice of the steps now to be described, which represent the crux of the invention.

The tobacco is dried continuously during its passage through dryer 23 on conveyor 24, and this drying may be accomplished in any suitable manner, preferably by circulating heated air through the dryer and the tobacco on conveyor 24. By suitable control of the temperature, air flow and time of passage through the dryer, the extent of drying may be controlled within fairly defined limits, as may be established by tests upon samples of the dryer-discharged tobacco. In the practice of this invention, these factors are controlled to produce a much less drastic drying action than has been conventional at this stage of prior art practice, the drying being carried only to the range of approximately 20-40% moisture content, and preferably within the range of 24-38%. This fact coupled with the further features discussed below, provides a considerable simplification and im-v provement in the total process and resulting product.

At the completion of this preliminary drying step, the

product is bulked to obtain substantially uniform redis tribution of moisture. This is important both in obtaining a uniform final product and in avoiding the chance that there may be such brittleness in any part of it as to destroy it in the ensuing cutting step. The bulking operation is accomplished in manner'which is known per se, by maintaining the tobacco in a fairly thick bed for suflicient time to permit this moisture redistribution to occur. While this may be done in different ways, continuously or in batch, I prefer to run the tobacco from the dryer conveyor 24 onto the bulking conveyor 25, which runs at a much slower rate of speed than the dryer conveyor, so that the tobacco piles up in a relatively thick bed on conveyor "25. By piling up tobacco on conveyor 25 during slow forward movement for one shift and maintaining it there between shifts, adequate time will be provided for moisture equalization before the next day if the plant is on one shift operation, and the bulking will thereafter be continuous, along with the rest of the operation, on subsequent days, tobacco from the previous day being discharged from the right hand end of bulking conveyor 25 at the same time that tobacco from the current output of dryer 23 is received at its left hand end. Thus, the progression of tobacco may be interrupted periodi-cally to permit sufficient time for completion of bulking. If, on the other hand, the plant is on multi-shift operation, the same result of continuous operation while allowing adequate bulking time may be attained by providing a greater length of bulking belt, or slowing down its rate of travel.

From the bulking operation as discussed above, the tobacco may be passed continuously by cross conveyors 26 into a cutting machine 27, which may be of any suitable type designed to cut the tobacco into the desired particle size. By performing the cutting at this stage, it is possible to obtain a pervious mass well-adapted to the later final drying step, while at the same time avoiding the destruction by which a substantial part is converted to dust or powder if cutting is undertaken after substantial further drying.

The cut tobacco particles are delivered by conveyor 28 to a classifier 29, which may be of the type having a screen which passes only the particles which have been cut to the desired degree of fineness. These particles are discharged from the underside of the classifier by conveyors 30 and 31 into the oscillating feed mechanism 32 of the final drier 33. The coarse particles which fail to pass through the classifier screen, on the other hand, are discharged from the right hand end and returned by conveyor 34 to the feed end of the cutter 27, so that they may be recut to the desired size in recirculation through the cutter.

After being discharged by the oscillating feed 32 as a uniform bed onto the pervious conveyor 35 of drier 33, the cut tobacco particles are passed on this continuously moving conveyor through the dryer at a rate which is related to the heat and air fiow to dry the tobacco to the ultimately desired point (e. g. 810%) as it emerges from the conveyor 35 and is fed thence by conveyor 36 to storage or packaging equipment or to cigarette making machinery.

It will be seen from the above discussion that the steps of the process are performed during the continuou movement of the tobacco from start to finish. This contributes not only to rapid and systematic operation, but also to uniformity of treatment and condition in the successive stages.

While the invention has been described specifically in relation to particular details of processing steps and equipment, persons skilled in the art will be aware that these detail may be varied withinthe scope'of the invention.

Since various modifications are available, I Wish it to be understood that interpretation of the scope of the invention is not to be limited except by the following claims.

I claim:

1. In the processing of tobacco strips to provide dipped filler smoking tobacco, the process comprising passing the strip through a clipping solution and thereby impregnating the same with the desired flavoring constituents, passing the impregnated strips continuously from said dipping solution through a drying zone and subjecting the same to the drying action of heated air blown through that "zone, discharging the tobacco continuously from 'said drying zone while stillhaving a moisture content averaging between 20% and 40%, passing the resulting tobacco directly from said drying zone in depth continuously on a bulking conveyor until the moisture content is substantially uniformly redistributed, continuously cutting the tobacco into relatively small particle size upon completion of bulking and delivery from said bulking conveyor, and thereafter passing the cut tobacco through a further drying zone and there completing the drying thereof.

2. A process as defined in claim 1 in which the bulking operation continues during continuous progression of the tobacco through the steps of the process as aforesaid, but in which such progression is interrupted periodically to permit sufficient time for completion of bulking, and in which progression of tobacco through the dipping and drying steps is also discontinued during such interruption.

References Cited in the file of this patent UNITED STATES PATENTS 102,560 Lilienthal May 3, 1870 585,759 Hysore July 6, 1897 601,654 Hysore Apr. 5, 1898 1,339,375 Buensod May 4, 1920 2,130,880 Durning Sept. 20, 1938 2,179,644 Rundell -Nov. 14, 1939 FOREIGN PATENTS 314,950 Great Britain May 1, 1930 755,189 France Sept. 4, 1933

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