US3664351A

US3664351A - Cigarette-making machinery

Info

Publication number: US3664351A
Application number: US12642A
Authority: US
Inventors: Frederick Russell
Original assignee: Brown and Williamson Tobacco Corp
Current assignee: Brown and Williamson Holdings Inc
Priority date: 1969-02-27
Filing date: 1970-02-19
Publication date: 1972-05-23
Anticipated expiration: 1989-05-23
Also published as: GB1224972A; DE2008827A1

Abstract

The invention is concerned with an apparatus and a method for the treatment of cut tobacco in a cigarette-making machine in which a stream of tobacco strands carried in a stream of air is subjected to microwave-radiation energy by passing it through a radiation chamber. Suitably, the wavelength of the microwave energy is in the range from 10 to 100 cms. and the stream of air carrying the tobacco is directed through the chamber at a substantial distance from the chamber walls where the energy level is low. The path of the tobacco strands through the chamber is defined by a pair of confronting end walls having straight inlet and outlet portions at their ends, and an arcuate portion therebetween that is convex toward a wave-guide that terminates in an outlet communicating with the interior of the chamber. The straight portions serve as microwave-retaining filters and the confronting walls are transparent to the passing of microwaves therethrough. A rotating fan is positioned to the passing of microwaves therethrough. A rotating fan is positioned in the chamber between the confronting walls and the energy inlet and serves to cool the adjacent arcuate wall. Tobacco leaving the chamber is formed into a filler stream and into a rod from which cigarettes may be cut.

Description

United States Patent Russell 1 May 23, 1972 [54] CIGARETTE-MAKING MACHINERY Primary Examiner-Joseph S. Reich [72] Inventor: erick Russell Southampton England Attorney-Kane, Dalsimer, Kane, Sullivan and Kurucz [73] Assignee: Brown and Williamson Tobacco Corporation, Louisville, Ky. ABSTRACT I [22] Filed: Feb, 19, 1970 The invention is concerned with an apparatus and a method for the treatment of cut tobacco in a cigarette-making [21] Appl' 12,642 machine in which a stream of tobacco strands carried in a stream of air is subjected to microwave-radiation energy by 30 F re A a m it passing it through a radiation chamber. Suitably, the I 1 o is ppuca on y Data wavelength of the microwave energy is in the range from to Feb. 27, 1969 Great Britain ..10,509/69 100 cms. and the stream of air carrying the tobacco is directed through the chamber at a substantial distance from the [52] US. CL... ....131/l10, 131/121, 131/84 B Chamber walls where the energy level is low. The path of the [51] Int. Cl. ..A24b 9/00, A24c 5/14 tobacco strands through the chamber is defined by a pair of [58] Field at Search ..131/1 10, 121, 84, 84 B, 84 C, confr n ng en w l having str g nl n le p r ons 131/21, 21 B, 21 A, 140 P at their ends, and an arcuate portion therebetween that is convex toward a wave-guide that terminates in an outlet commu- [56] References Ci d nicating with the interior of the chamber. The straight portions serve as microwave-retaining filters and the confronting UNITED STATES PATENTS walls are transparent to the passing of microwaves therethrough. A rotating fan is positioned to the passing of g i a'j microwaves therethrough. A rotating fan is positioned in the 3494722 M1970 a e chamber between the confronting walls and the energy inlet 3255763 6 1966 131/121 x and serves to cool the adjacent arcuate wall. Tobacco leaving l 1 3 ll 12] X the chamber is formed into a filler stream and into a rod from 2,222,634 11/1940 Sm1th..... .131/121 UX which cigarettes may be cm 3,019,793 2/1962 Labb.... ....131/110 X 2,497,501 2/1950 Himmel et a1 ..13l/121 X 9 Claims, 3 Drawing Figures 1:! 72 1 I i 1 w 73 O ?ATENTE[]MAY23'I972 3,664,351

SHEET 2 UF 2 INVENTOR FREDERKLK RU SSELL CIGARETTE-MAKING MACHINERY This invention concerns improvements relating to cigarettemaking machinery and particularly to machines in which the cut tobacco is delivered to the forming mechanism by an air stream.

In the conventional manufacture of continuous tobacco rods, it is well known that during the forming process, and particularly in the gamiture, some physical degradation of the tobacco strands occurs. This degradation can be reduced if the moisture content or the temperature of the tobacco, or both, can be raised, so increasing the pliability of the strands. While the moisture content can be raised quite readily, cigarettes are then produced which have an undesirably high moisture content for subsequent packing operations and inconvenient delays are incurred while the moisture-content of the cigarettes is adjusted to a suitable value for packing. Heating the tobacco has been found to be technically difficult, since the provision of sufficient heat to produce any marked rise in the temperature of the rapidly moving stream of tobacco strands involves considerable problems of heat transfer.

An object of the present invention is to provide an apparatus and a method whereby the pliability of tobacco strands being supplied to a cigarette-making machine can readily and easilybe increased.

According to the invention, a stream of tobacco strands carried in a stream of air is subjected to microwave-radiation energy by passing it through a radiation chamber. Suitably, the microwaves may be of a wavelength in the range from to 100 cms. Such waves may be directed to the radiation chamber by an accurately formed wave-guide. Preferably, the stream of air carrying the tobacco strands is directed through the chamber at a substantial distance from walls where the energy level is low, and is guided in a desired path by delimiting walls of material transparent to microwave energy, for example polypropylene. If desired, an agitator in the form of a fan may be used within the radiation chamber. Filter means may be provided at the chamber inlet and outlet for the stream of tobacco strands to ensure that the microwave energy is completely retained within the radiation chamber.

By such treatment, the pliability of the tobacco strands can be increased, so reducing the losses of tobacco as dust during processing. The tobacco strands may have increased filling power and the cigarettes produced therefrom may have a moisture content at or near the optimum value for packing procedures.

One manner of carrying the invention into effect, by way of example, will now be more fully described with reference to the accompanying drawings, in which:

FIG. 1 is a substantially vertical section (on the line l-I in FIG. 2) through a suitable form of radiation chamber and associated tobacco-conveying means,

FIG. 2 a side elevation, of the chamber alone, broken away in places to disclose underlying parts, and

FIG. 3 a transverse section on the line III-III in FIG. 2.

The radiation chamber illustrated comprises a box 1 of nearly square trapezium shape in side elevation (FIG. 2) and of elongated rectangular shape in vertical and transverse sections (FIGS. 1 and 3). The chamber is composed of

walls

2, 3, 4, 5, of radiation-impervious material, secured tightly together, with seals at 6. The radiation is supplied to the chamber 1 from a source of high frequency energy 7 through a guide 8 leading to an opening 9 in the large wall 2 so located that the distribution of energy is substantially transversely uniform as it traverses the chamber. If desired, however, energy may be supplied to the chamber at two or more positions along the tobacco path. Suitably, the source 7 may be a magnetron valve operating at a frequency within the microwave band. A fan 10 disposed in the chamber 1 and driven by an external electric motor 11 serves to cool the adjacent arcuate wall 12.

Walls

12, 13 of propylene plastic material bound a path 14, within the chamber 1, for an air stream carrying the tobacco through the said chamber. In order to produce a wide,

thin stream of tobacco-carrying air, the path 14 is narrow in vertical section (FIG. 1), but extends for the full transverse dimension (FIG. 3) of the chamber and from the lower to the upper edge of the wall 3 away from the source 7 of the radiation. In the vertical section, the

walls

12, 13 are of an arcuate shape, so that the path 14 is of a curved form, convex towards the wall 2, and is spaced away from the walls, 2, 3 throughout most of its course. At the ends of the curved path 14, there are short, substantially straight, upright path sections 15 and I6 dimensioned and arranged to serve as microwave retaining filters.

In FIG. I, the radiation chamber 1 is shown mounted in place of a conventional tobacco-conveying arrangement below the moving perforated collection band, operating with suction, which leads to known rod-forming apparatus of a cigarette-making machine. This band moves in a groove 17 in a guide 18 below a slot in the bottom of a suction chamber 19, tobacco issuing from the path section 16 being carried away on the underside of the said band. Near its upper edge, the wall 13 is formed with a band of small perforations forming a grille 20 permitting removal, by way of a perforated-metal filter 21 for microwave energy and a duct 210 FIG. I), of part of the tobacco-conveying air stream just before the issuing tobacco arrives at the aforesaid moving, perforated, band of the machine, where its conveyance is taken over by the latter.

The cut cigarette tobacco may be supplied to the lower end of the path 14 through the chamber 1 by known tobacco-feeding means. As illustrated in FIG. 1, tobacco furnished by rolls 22,23 is fed by a toothed roll 24 as an even thin layer 25 to the outer surface of a rotating gauze drum 26 whose interior is subject to suction by way of a duct 27. The effect of the suction in causing adherence of the tobacco layer to the drum 26 is limited to the bottom arc thereof by stationary masking pieces 28 inside the drum, the tobacco being released as it approaches the path-section 1 5. Air flows in from below as indicated by the arrows 29 and part of this air entrains the tobacco and conveys it through the path 14. A series of fixed vanes 30 assists in guiding the tobacco.

The following is an example of the treatment of cigarette tobacco, using the above-described radiation chamber, the path 14 having a length of about 53 cms., a width of about 58 cms. and a thickness of about 0.8 cms.

Strands of Virginia flue-cured tobacco cut at 55 cuts per inch and with a moisture content of 13.75 percent were fed to the path 14 through the chamber 1 at a rate of 5 lbs/minute. Microwave radiation energy was supplied from the source 7 at a rate of 1.5 KW. The rate of air flow through the path 14 was approximately 120 cu.ft./min. up to the grille 20, and, as part of the air issues through the duct 21a, approximately 40 cu.ft./min. from that point to the chamber 19. The temperature of the air in the path 14 was F., but as microwave energy generates heat from inside the tobacco the air temperature was not a measure of the temperature of the tobacco.

This treatment reduced the moisture content of the tobacco by about 0.75 percent, The cigarettes produced from the tobacco had a moisture content suitable for packing and pliability that avoided excessive degradation of the tobacco strands in the rod-forming process in the machine.

I claim:

1. A microwave apparatus mounted on a cigarette-making machine for treatment of cut tobacco comprising: means providing a radiation chamber having inlet and outlet openings for tobacco strands at opposite ends thereof formed therein and a pair of confronting arcuate walls positioned in spaced relation to each other and formed of a material transparent to microwave energy, said walls being mounted in the chamber to the inlet and outlet openings at their respective ends so as to define a path for passing a stream of tobacco strands means providing stream of air for carrying said tobacco stream therethrough; means for generating microwave radiation energy mounted to the chamber and means for directing the radiation energy into and through the radiation chamber whereby the tobacco between said walls is subjected to radiation energy which renders the tobacco strands more pliable.

2. The apparatus according to claim 1 wherein the means for generating microwave energy produces a wave length of microwave energy in the range of from to 100 cms.

3. The apparatus according to claim 1 wherein the walls defining the path for passing the stream of tobacco strands carried on a stream of air through the chamber is disposed in the radiation chamber at a distance remote from a microwave generating means.

4. The apparatus according to claim 1 wherein the walls defining said path for passing said stream of tobacco strands carried on said stream of air through said chamber extend across the chamber, the walls being convex with respect to the side of the chamber from which the microwave generating means is mounted.

5. The apparatus of claim 1 wherein a fan is mounted within the radiation chamber so that portions of the fan lie within the path of the microwave generating means.

6. The apparatus of claim 1 wherein the radiation chamber has mounted adjacent the inlet and outlet openings microwave filter means for the stream of tobacco-carrying air in order to retain the microwave energy within the chamber.

7. A method of treating cut tobacco in a cigaretteqnaking machine comprising: passing a stream of tobacco strands carried in a stream of air into and through a microwave radiation chamber conducting the tobacco strands along an arcuate path defined by a pair of spaced confronting walls made of a material transparent to microwave energy, then subjecting the tobacco strands to microwave radiation energy from said source while said tobacco is conducted along said path whereby the treated tobacco strands are rendered more pliable.

8. A microwave apparatus mounted on a cigarette making machine for treatment of cut tobacco comprising: a radiation chamber having inlet and outlet openings formed therein and a pair of confronting walls positioned in spaced relation to each other and formed of a material transparent to microwave energy, pneumatic and mechanical means for passing a stream of air and tobacco strands between said walls, said walls being mounted in the chamber to the inlet and outlet openings at their respective ends so as to define a path for passing said stream therethrough; means for generating microwave radiation energy mounted to the radiation chamber; means for directing the radiation energy through the radiation chamber whereby the tobacco in said stream is subjected to radiation energy which renders the tobacco strands more pliable; said spaced walls being curved from the inlet opening to the outlet opening such that the convex portion of the curve lies toward the side of the radiation chamber from which the microwave energy generating means is mounted.

9. A microwave apparatus mounted on a cigarette-making machine for the treatment of cut tobacco comprising: a radiation chamber having inlet and outlet openings and a pair of confronting walls positioned in spaced relation to each other and formed of a material transparent to the microwave energy, pneumatic and mechanical means for passing a stream of air and tobacco strands between said walls, said walls being mounted in the chamber to the inlet and outlet openings at their respective ends so as to define a path for passing said stream therethrough; means for generating microwave radiation energy mounted to the radiation chamber; and means for directing the radiation energy through the radiation chamber whereby the tobacco is subjected to radiation energy which renders the tobacco strands more pliable; microwave filter means mounted to the chamber and positioned adjacent the inlet and outlet openings for the air and tobacco stream in order to retain microwave energy within the radiation chamber.

Claims

2. The apparatus according to claim 1 wherein the means for generating microwave energy produces a wave length of microwave energy in the range of from 10 to 100 cms.

7. A method of treating cut tobacco in a cigarette-making machine comprising: passing a stream of tobacco strands carried in a stream of air into and through a microwave radiation chamber conducting the tobacco strands along an arcuate path defined by a pair of spaced confronting walls made of a material transparent to microwave energy, theN subjecting the tobacco strands to microwave radiation energy from said source while said tobacco is conducted along said path whereby the treated tobacco strands are rendered more pliable.