GB2039714A

GB2039714A - Recovering waste tobacco

Info

Publication number: GB2039714A
Application number: GB7843920A
Authority: GB
Original assignee: Tobacco Res & Dev
Current assignee: Tobacco Res & Dev
Priority date: 1978-11-09
Filing date: 1978-11-09
Publication date: 1980-08-20

Abstract

Shredded waste tobacco material is fed to a double decker separation device, the upper deck of which is formed of a screen through which tobacco strands can pass and the lower deck being riffled. The double decker is inclined at such an angle and vibrated at such a frequency and amplitude that paper and tobacco pass up the screen, with tobacco passing through the screen holes, and heavy particles such as filter ends move down the screen. On the riffled deck tobacco strands move up and grit particles move down. <IMAGE>

Description

SPECIFICATION The recovery of waste tobacco This invention relates to the recovery of waste tobacco from waste cigarettes.

In various places in a cigarette factory cigarettes are rejected as being off standard. Also when things go wrong, long strands of cigarette rod may go to waste. This waste cigarette material contains valuable tobacco in admixture with paper and filter ends.

In order to recover the tobacco, the waste is shredded and then the shredded material is subjected to a separation process. The separation process is the difficult part and up to now no satisfactory automatic separation process has come into use. Existing processes which separate paper particles satisfactorily from tobacco strands are more or less labour intensive.

In DOS 2 032 706 a machine has been described which is not so labour intensive. In that proposal shredded waste tobacco is screened on a screen with a flat inclination. All materials move down the screen and tobacco strands pass through the screen, are collected on a surface vibrating with a screen, and pass along that surface also in a downward direction. The machine has no facility for separating grit from the tobacco strands. Also paper and filter ends are collected together.

SUMMARY OF THE INVENTION According to the invention a method of recovering tobacco strands from shredded waste tobacco material comprises the steps of screening the material through screen holes in a surface allowing tobacco strands to pass through the surface having an angle of inclination and an amplitude of vibration causing paper to move upwardly and filter ends to move downwardly, and tabling the undersize material at the same amplitude of vibration to separate tobacco strands and grit particles in the undersize material.

Apparatus for treating the material comprises a screen, a riffled table below the screen ana spaced from it the screen and table forming a single unit, means for resiliently supporting the unit at an angle to the horizontal, and means for imparting vibratory movement to the unit in the direction of inclination, the riffles being transverse to that direction, wherein paper in material fed to the centre of the screen moves up the inclination, filter ends move down, tobacco strands pass through the screen and tobacco strands and grit passing through the screen are separated on the table.

The angle of inclination is preferably between 30 and 400, the frequency of vibration between 13 and 1 5 Hz and the amplitude of vibration between 10 and 1 5 mm. The screen holes should have an average opening of about 6 mm.

DESCRIPTION OF THE DRAWINGS Figure 1 is a diagrammatic side view of a separation table according to the invention, and Figure 2 is a section on the line 2-2 in Figure 1.

DESCRIPTION OF A PREFERRED EMBODIMENT In the illustrated embodiment an inclined trough 3 is supported on a stand 4 by means of a series of leaf springs 5 and vibrated by means of a conventional motor and crank.

The trough has a false bottom formed of a screen 6 made of stainless steel and a true bottom 7 which is formed with riffles transverse to the long axis of the trough. At its top end 11 the trough extends horizontally to a discharge position 12 and at that extreme end the screen 6 extends beyond the bottom 7 to a discharge position 13.

Shredded waste material is fed to the device at the position of the arrow 1 0. Light particles tend to move up the screen 3 while heavy particles move down. Strands of tobacco which have been properly freed, pass through the screen openings and land on the riffles bottom, There they also move upwardly while grit particles move down to 14. Coarse heavy particles such as filter ends move down the screen 6 to 1 5.

For all this to happen the parameters have to be correctly chosen. In one embodiment the following parameters have been found to give satisfactory results: Screen openings: 6 mm Stroke: 13 mm Frequency: 1 3-15 Hz Angle of springs to 25 strand: Angle of trough to the 340 Horizontal:

CLAIMS 1. A method of recovering tobacco strands from shredded waste tobacco material comprising the steps of screening the material through screen holes in a surface allowing tobacco strands to pass through the surface having an angle of inclination and an amplitude of vibration causing paper to move upwardly and filter ends to move downwardly, and tabling the undersize material at the same amplitude of vibration to separate tobacco strands and grit particles in the undersize material.

2. The method claimed in claim 1 in which the angle of inclination is between 30 and 400.

3. The method claimed in any of the above claims in which the frequency of vibration is between 13 and 15 Hz.

4. The method claimed in any of the above claims in which the amplitude of vibration is between 10 and 15 mm.

5. Apparatus for treating shredded waste tobacco material comprising a screen, a riffled table below the screen and spaced from it, the screen and table forming a single unit, means for resiliently supporting the unit at an angle to the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION The recovery of waste tobacco This invention relates to the recovery of waste tobacco from waste cigarettes. In various places in a cigarette factory cigarettes are rejected as being off standard. Also when things go wrong, long strands of cigarette rod may go to waste. This waste cigarette material contains valuable tobacco in admixture with paper and filter ends. In order to recover the tobacco, the waste is shredded and then the shredded material is subjected to a separation process. The separation process is the difficult part and up to now no satisfactory automatic separation process has come into use. Existing processes which separate paper particles satisfactorily from tobacco strands are more or less labour intensive. In DOS 2 032 706 a machine has been described which is not so labour intensive. In that proposal shredded waste tobacco is screened on a screen with a flat inclination. All materials move down the screen and tobacco strands pass through the screen, are collected on a surface vibrating with a screen, and pass along that surface also in a downward direction. The machine has no facility for separating grit from the tobacco strands. Also paper and filter ends are collected together. SUMMARY OF THE INVENTION According to the invention a method of recovering tobacco strands from shredded waste tobacco material comprises the steps of screening the material through screen holes in a surface allowing tobacco strands to pass through the surface having an angle of inclination and an amplitude of vibration causing paper to move upwardly and filter ends to move downwardly, and tabling the undersize material at the same amplitude of vibration to separate tobacco strands and grit particles in the undersize material. Apparatus for treating the material comprises a screen, a riffled table below the screen ana spaced from it the screen and table forming a single unit, means for resiliently supporting the unit at an angle to the horizontal, and means for imparting vibratory movement to the unit in the direction of inclination, the riffles being transverse to that direction, wherein paper in material fed to the centre of the screen moves up the inclination, filter ends move down, tobacco strands pass through the screen and tobacco strands and grit passing through the screen are separated on the table. The angle of inclination is preferably between 30 and 400, the frequency of vibration between 13 and 1 5 Hz and the amplitude of vibration between 10 and 1 5 mm. The screen holes should have an average opening of about 6 mm. DESCRIPTION OF THE DRAWINGS Figure 1 is a diagrammatic side view of a separation table according to the invention, and Figure 2 is a section on the line 2-2 in Figure 1. DESCRIPTION OF A PREFERRED EMBODIMENT In the illustrated embodiment an inclined trough 3 is supported on a stand 4 by means of a series of leaf springs 5 and vibrated by means of a conventional motor and crank. The trough has a false bottom formed of a screen 6 made of stainless steel and a true bottom 7 which is formed with riffles transverse to the long axis of the trough. At its top end 11 the trough extends horizontally to a discharge position 12 and at that extreme end the screen 6 extends beyond the bottom 7 to a discharge position 13. Shredded waste material is fed to the device at the position of the arrow 1 0. Light particles tend to move up the screen 3 while heavy particles move down. Strands of tobacco which have been properly freed, pass through the screen openings and land on the riffles bottom, There they also move upwardly while grit particles move down to 14. Coarse heavy particles such as filter ends move down the screen 6 to 1 5. For all this to happen the parameters have to be correctly chosen. In one embodiment the following parameters have been found to give satisfactory results: Screen openings: 6 mm Stroke: 13 mm Frequency: 1 3-15 Hz Angle of springs to 25 strand: Angle of trough to the 340 Horizontal: CLAIMS

1. A method of recovering tobacco strands from shredded waste tobacco material comprising the steps of screening the material through screen holes in a surface allowing tobacco strands to pass through the surface having an angle of inclination and an amplitude of vibration causing paper to move upwardly and filter ends to move downwardly, and tabling the undersize material at the same amplitude of vibration to separate tobacco strands and grit particles in the undersize material.

5. Apparatus for treating shredded waste tobacco material comprising a screen, a riffled table below the screen and spaced from it, the screen and table forming a single unit, means for resiliently supporting the unit at an angle to the horizontal, and means for imparting vibratory movement to the unit in the direction of inclination, the riffles being transverse to that direction, wherein paper in material fed to the centre of the screen moves up the inclination, filter ends move down, tobacco strands pass through screen and tobacco strands and grit passing through the screen are separated on the table.

6. The apparatus claimed in claim 5 in which the angle of inclination is between 30 and 400.

7. The apparatus claimed in either of claims 5 or 6 in which the vibrating means operates at a frequency of between 1 3 and 1 5 Hz.

8. The apparatus claimed in any of claims 5 to 7 in which the throw of the unit is between 10 and 15 mm.

9. The apparatus claimed in any of claims 5 to 8 in which the average screen opening is 6 mm.

10. A method of recovering waste tobacco substantially as herein described with reference to the accompanying drawings.

11. Apparatus for recovering waste tobacco substantially as herein described with reference to the accompanying drawings.