US2959176A

US2959176A - Pre-treating raw tobacco

Info

Publication number: US2959176A
Application number: US707367A
Authority: US
Inventors: Dock Nils
Original assignee: Svenska Flaktfabriken AB
Current assignee: Svenska Flaktfabriken AB
Priority date: 1957-01-05
Filing date: 1958-01-06
Publication date: 1960-11-08
Anticipated expiration: 1977-11-08

Description

Nov. 8, 1960 N. DOCK FEE-TREATING RAW TOBACCO Filed Jan. 6, 1958 United States Patent 2359470 PRE-TREATING RAW TOBACCO Nils Dock, Bromma, Sweden, assignor'to Aktiebolaget The present invention relates to a method and apparatus for pre-treating raw tobacco packed in cases or bales for storage in the manufacture of cigarettes.

In the manufacture of cigarettes or similar tobacco products it is common to mix raw-tobacco of a great number of varieties. Although the manufacturing capacity is relatively great, the consumption of each separate variety of tobacco will thus be considerably smaller. Raw tobacco from U.S.A. is, for instance, as a rule packed in barrel-shaped cases containing about 450 kg. Each separate portion from such a case will often be as small as kg. In order to prevent the tobacco from being unnecessarily crushed during this portioning the case must first be moistened. Such moistening is usually carried out by means of vapor, which will give the whole case a temperature of 60-70 C. During the following relatively rapid cooling which may occur during 3-5 hours in an open space the tobacco unavoidably loses part of its moisture and furthermore there is a risk that the tobacco will become discolored and will deteriorate in taste. There has, therefore, for a long time been a demand for a new method of loosening and storing the whole case directly after its moistening for future portionings. The present invention relates to a new and improved method of loosening the contents of the whole tobacco cases for the subsequent storing lot by lot in open storage spaces for the continuous manufacturing process which spaces are situated in or adjacent the manufacturing room proper. From said spaces the loosened tobacco in portioned in a usual manner according to the tobacco recipe for the brand being manufactured. Because of this new method, the tobacco will not lose any moisture or be subject to any quality deterioration regardless of the length of the storing time.

The method according to the invention is mainly characterized in that the raw-tobacco in unbroken packing units is humidified and simultaneously heated by being treated in an atmosphere saturated with vapor. The bulk then being mechanically loosened and by means of an injector introduced into a pneumatic transport system operating with cold air saturated with moisture, and further in that said tobacco is transported in serpentine shaped passages for simultaneously cooling and loosening same, the loosened tobacco then being separated in a known manner and directly transferred to said storage space. The total time necessary for the cooling and loosening only amounts to a few seconds.

The transporting air can after the separation of the tobacco suitably be cleansed and after re-conditioning be recirculated in said pneumatic transport system.

The invention involves a number of other advantages besides the advantages of enabling storage with maintained quality. As the tobacco after treatment in accordance with the invention during its entire storing time maintains its loose condition, it will be easier to weigh more exactly and without any substantial waste th: necessary portions of the various varieties of a certain mixture.

The invention will now be described more in detail with reference to the accompanying drawing, illustrating an apparatus suitable for the performance of the method. {51111 the drawing, 1a designates a device for the moisteninggof rawtobacco by means of vapour and simultaneously'heating the tobacco to atemperature of 60-70? C. During this treatment the raw-tobacco is in its original compact bulk form. After this treatment the tobacco is loosened either manually or by means of a mechanical disintegrator, in the drawing designated 1b. After its loosening, the tobacco is transported by means of a suitable transport device 10 to a feeding injector 1d, by means of which the tobacco is introduced into a pneumatic transport system operating with saturated cold air. The tobacco is during its transport caused to pass in serpentine shaped passages 2 for simultaneously cooling and finally loosening the same. Owing to the shape of the passages and a choice of a suitable proportion between the quantity of tobacco and the quantity of transporting air a complete loosening and a rapid and effective cooling of the tobacco is obtained. The time necessary for this part of the treatment will only be a few seconds. From a precipitation chamber 3, where the tobacco is separated from the transporting air, the tobacco by means of a sluicing device 4 is fed to the open storing space 5, intended for the tobacco variety being treated for the purpose of storing and subsequent use in the continuous manufacturing process. After separation from the tobacco the transporting air is in the illustrated embodiment passed by a duct 6 to a transporting ventilator or fan 7 to be recirculated in said pneumatic transport system. 8 designates a cooling device for said recirculated air and the device is equipped with spraying means for the supply of a cooling medium, which is supplied through a pipe 9. The cooled and moistened air is thereafter passed to a dynamic separator 10 of cyclone type for separating of a fog of liquid particles and dust particles, if any. 11 designates a duct for the discharge of the cooling medium and separated dust. The air being cleansed in the separator 10 is discharged through the outlet 12 and is passed through a connecting duct 13 back to the feeding injector 1d.

Instead of the shown recirculation of the transporting air, said air may be discharged to the atmosphere after the separation of the tobacco, and fresh transporting air may be supplied to the transporting ventilator or fan 7. In the illustrated embodiment, the elements 8 and 10 may be of the design disclosed in US. Patent No. 2,883,167, granted April 24, 1959, to Evert Krantz and US. Patent No. 2,881,858, granted April 14, 1959, to Evert Krantz et al., owned by the assignee of the present application, or they may be of any other standard design without departing from the scope of the invention as defined in the appended claim.

What I claim is:

In the manufacture of cigarettes, the process of conditioning raw tobacco packed in cases or bales for storage in moist condition and loose form comprising the steps of humidifying and simultaneously heating the raw tobacco in said cases or bales by a heated atmosphere saturated with vapor to moisten and heat the tobacco, mechanically removing the tobacco from the cases or bales and mechanically loosening the bulk to form clumps of heated moist tobacco, continuously introducing the clumps of tobacco into a stream of cold air saturated with moisture, causing said stream to flow in serpentine-shaped paths to effect loosening of said clumps simultaneously with cooling and transportation of said moist tobacco without moisture loss, and separating the cooled Patented Nov. 8, 1960,

2,959,176 3 r 3 and loosened moist tobacco from said stream and direct- FOREIGN PATENTS 1y transferring the tobacco to the storage space in cool,

158,380 Sweden Mar. 26, 1957 mOlst and loose condition. 177,363 Austria Jan. 25, 1954 V r 5 ,061 G ....n References Cited in the file of this patent 5 39 ermany 1931 UNITED STATES PATENTS OTHER, REFERENQES Drylng and Processing of Materials by Means of 3 BllellSOd 29, 1925 Conditioned Air, Air-Carrier Engineering Corp., pages 1,832,119 Hohn et a1. N 17, 1931 103-104, published 1929 by Carrier Engineering Corpo- '2,467,248 Arelt Apr. 12,, 19 9, 10 ration, Newark, NJ.