GB2431003A

GB2431003A - Apparatus for capturing smoke

Info

Publication number: GB2431003A
Application number: GB0520285A
Authority: GB
Inventors: Timothy James Peter Mason; Ian Francis Tindall
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 2005-10-05
Filing date: 2005-10-05
Publication date: 2007-04-11
Also published as: GB0520285D0

Abstract

An apparatus for capturing smoke from a smoking article comprises a capture bag having an opening for receiving the smoke, a sealed chamber in which the capture bag is located, the opening of the capture bag passing through the sealed chamber, and means for connecting the inside of the sealed chamber to a vacuum source. The apparatus is arranged such that, when a reduced air pressure is applied to the inside of the sealed chamber by the vacuum source, the capture bag expands thereby drawing the smoke into the capture bag. The apparatus is suitable for capturing side stream smoke from a mechanical smoking machine.

Description

1 2431003

APPARATUS FOR CAPTURING SMOKE

The present invention relates to an apparatus for and method of capturing smoke from a smoking article. The present invention has particular (but not exclusive) application in capturing so called side stream smoke from a mechanical smoking machine.

Cigarettes, cigars and the like are smoked in mechanical smoking machines to determine the composition of the smoke constituents drawn into the lungs of the smoker. This is known in the industry as "main stream smoke" and forms the basis of legal declarations of nicotine, carbon monoxide and smoke in the smoke of the cigarette or cigar.

The smoke generated between puffs is usually conveyed away from the cigarette in such mechanical smoking machines and extracted safely to the atmosphere. This smoke is known as "side stream smoke". Considerable interest in the composition of this side stream smoke has arisen. The side stream smoke will differ chemically from the mainstream smoke as combustion characteristics differ from the main stream "puff' and there is no filtering effect of the tobacco colunm and filter tip if fitted.

This interest has resulted in the development of standard methods for the smoking of cigarettes and cigars that allow capture of this side stream smoke that can be analysed further for its chemical composition.

In known techniques for capturing side stream smoke, the smoke is passed through a physical capture device that capture particulates and vapours, but which passes constituents in the gas phase. The gas phase of the smoke is usually captured in an inflatable bag. When the smoking has terminated the inflatable bag is either moved to a gas analysis machine for analysis of the gas, or samples are taken from the bag and passed to an analyser by means of valves and pumps.

Each article to be smoked must have a controlled flow of air over the smoking article.

For example, some tests require a controlled flow of 3 litres of air per minute over the smoking article. The air and smoke mixture must then be conveyed to the capture bag. Conventionally this involves the use of an individual pump and bag with suitable valves and flow controllers.

A problem which may arise in the conventional technique for side stream smoke capture is that, where a number of smoking articles are to be smoked at the same time, the replication of pumps, valves and controls for each cigarette may make the machine complex and costly. Normally linear smoking machines for mainstream smoking provide the capability to smoke cigarettes in groups of, for example, 5, 10 or 20. For a 20 channel side stream machine the cost of pumps and controls could be prohibitively expensive.

Another problem which may arise is the need for a pump to be located in the path of the air and smoke mixture, which may lead to contamination of the sample and the accumulation of smoke particles in the pump.

According to a first aspect of the present invention there is provided an apparatus for capturing smoke from a smoking article, the apparatus comprising: a capture bag having an opening for receiving the smoke; a sealed chamber in which the capture bag is located, the opening of the capture bag passing through the sealed chamber; and means for connecting the inside of the sealed chamber to a vacuum source, wherein the apparatus is arranged such that, when a reduced air pressure is applied to the inside of the sealed chamber by the vacuum source, the capture bag expands thereby drawing the smoke into the capture bag.

The present invention may provide the advantage that smoke can be drawn directly into the capture bag without the need for a pump to be located in the path of the smoke. This may reduce the risk of contamination of the collected smoke, and avoid the collection of smoke particles in the pump.

The present invention may also provide the advantage that a plurality of capture bags can be inflated using a single pump, which may allow the capture apparatus to be less complex and more efficient than would otherwise be the case.

The apparatus may further comprise a flow controller connected to the opening of the capture bag. This can allow smoke to be drawn into the capture bag at a controlled rate. The flow controller may be fixed, manually operable, or automatically

adjustable.

Some smoking tests such as side stream smoking tests may require air to be passed over the smoking article at a carefully controlled rate. In order to achieve this, the apparatus may further comprise a control unit for adjusting the rate at which smoke is drawn into the capture bag. The control unit may be arranged to adjust operation of the vacuum source, or to adjust operation of a flow controller connected to the opening of the capture bag, or both. Preferably the control unit is part of a closed feedback loop, and thus the apparatus may further comprise a flow meter, and the control unit may be operable to adjust the rate at which smoke is drawn into the capture bag in dependence on an output of the flow meter. The control unit may be, for example, a suitably programmed processor.

It may be desirable to disconnect the capture bag from the smoke path before and/or after the smoking test, and thus the apparatus may further comprise means (such as a valve connected to the opening of the capture bag) for selectively connecting the capture bag to the smoke path.

Before the smoking test is carried out it may be necessary to ensure that the capture bag is empty. This can be achieved by connecting the capture bag to the atmosphere, and increasing the pressure inside the sealed chamber. Thus the apparatus may further comprise means (such as a valve, which may be the same valve as that discussed above or a different valve) for selectively connecting the capture bag to the atmosphere. Alternatively the capture bag could be selectively connected to a vacuum source, such as that used to extract air from inside the sealed chamber.

The apparatus may further comprise means for selectively connecting the capture bag to an external device, such as an analysis device. Such means may be a valve, which may be the same valve as that or those discussed above or a different valve. This can allow the captured smoke to be directed to a separate analysis device once the test is complete, without the need to remove the capture bag. The captured smoke may be expelled from the capture bag either by allowing a flow of air back into the sealed chamber, or by connecting the inside of the sealed chamber to a source of compressed gas, or a combination of both.

The apparatus may further comprise means (such as a valve) for selectively connecting the vacuum source to the inside of the sealed chamber. The apparatus may also comprise means (such as a valve, which may be the same valve or another valve) for selectively connecting the inside of the sealed chamber to the atmosphere. This can allow the contents of the capture bag to be expelled by allowing a flow of air into the sealed chamber. For example, captured smoke may be expelled to an external analysis device once the test is complete. Alternatively or in addition the apparatus may comprise means (such as a valve, which may be the same valve or a different valve) for selectively connecting the inside of the sealed chamber to a source of compressed gas. This can allow the capture bag to be evacuated before the test, if necessary, and/or allow captured smoke to be expelled to an external device The apparatus may further comprise a control unit for automatically controlling operation of at least one of the selective connecting means discussed above, so as to capture smoke in accordance with a predetermined smoking routine. This control unit may be the same as or different from that for adjusting the flow rate.

The present invention is particularly suitable for capturing the side stream smoke generated when a smoking article is smoked in a smoking machine, and thus the apparatus may be apparatus for capturing side stream smoke from the smoking article.

The apparatus may comprise a chimney for collecting the smoke to be captured. The chimney may be located next to the smoking article in order to capture side stream smoke.

The apparatus may comprise a plurality of capture bags located inside the sealed chamber for capturing smoke from a plurality of smoking articles. By using a plurality of capture bags inside a single chamber, a plurality of capture bags can be inflated using a single pump. This may significantly reduce the complexity of the apparatus and allow it to be operated more efficiently than if a separate pump were used for each capture bag.

According to another aspect of the present invention there is provided an apparatus for capturing side stream smoke from a plurality of smoking articles, the apparatus comprising: a plurality of capture bags, each having an opening for receiving smoke from a respective smoking article; a sealed chamber in which the capture bags are located, the openings of the capture bags passing through the sealed chamber; and a connector for connecting the inside of the sealed chamber to a vacuum source, wherein the apparatus is arranged such that, when a reduced air pressure is applied to the inside of the sealed chamber by the vacuum source, the capture bags expand thereby drawing the smoke into the capture bags.

The present invention also provides a smoking machine for main stream smoking of smoking articles, comprising an apparatus in any of the fonns discussed above.

According to another aspect of the present invention there is provided a method of capturing smoke in a capture bag, the capture bag being located inside a sealed chamber, the method comprising the steps of: smoking a smoking article; collecting smoke produced by the smoking article; connecting the capture bag to a path of the collected smoke; connecting the inside of the sealed chamber to a vacuum source; and applying a reduced air pressure to the inside of the sealed chamber by means of the vacuum source, thereby causing the capture bag to expand thereby drawing the smoke into the capture bag.

The method may further comprise the step of, before capturing the smoke, connecting the inside of the sealed chamber to a source of compressed gas so as to evacuate the capture bag. The method may be carried out using a plurality of capture bags inside the sealed chamber.

Any of the apparatus features described herein may be provided as method features and vice versa.

Preferred features of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 shows parts of a known side stream capture device; Figure 2 shows parts of a side stream capture device according to an embodiment of the present invention; and Figure 3 shows parts of a side stream capture device according to another embodiment of the present invention.

Referring to Figure 1, a known side stream capture device comprises a side stream capture chimney 10 connected to a pump 12 and a capture bag (not shown). The chimney 10 is located next to a cigarette 14 which is held in a holder. The holder is connected to a main stream smoking machine 16. In operation, the pump 12 draws air across the cigarette 14 as it is being smoked by the main stream smoking machine 16, so as to capture the side stream smoke that is generated as the cigarette is smoked.

Vapours and particulates are captured in a physical capture device 15, such as a Cambridge filter pad. The gas phase of the smoke is captured in an inflatable capture bag. The capture bag is initially deflated, and is inflated with the smoke as the cigarette is smoked.

Figure 2 shows parts of a side stream smoke capture device according to an embodiment of the present invention. The smoke capture device shown in Figure 2 is arranged to capture side stream smoke from five cigarettes at the same time.

Referring to Figure 2, five capture bags 20, 22, 24, 26, 28 are each located inside a sealed box 18. Each of the capture bags 20-28 has an opening which passes through the sealed box 18 to a respective valve 30, 32, 34, 36, 38. Each of the valves 30-38 has two positions. In a first position each valve connects its capture bag to a respective flow controller 40, 42, 44, 46, 48. In a second position each valve connects its capture bag either to the atmosphere, or to an analysis device (not shown). Each of the flow controllers 40-48 is connected to a side stream capture chimney (not shown), which may be a chimney such as that shown in Figure 1. Each of the side stream chimneys is arranged to capture the side stream smoke from a cigarette which is being smoked in a main stream smoking machine. Vapours and particulates may be captured in a physical capture device, such as a Cambridge filter pad (not shown).

The inside of the sealed box 18 is connected to a three way valve 50. The three way valve 50 is operable to connect the inside of the sealed box 18 to one of a source of compressed air 52, a vacuum generator 54, and the atmosphere.

Operation of the smoke capture device of Figure 2 is as follows. Before smoking is commenced, the valve 50 is operated so as to connect the source of compressed air 52 to the inside of the box 18. This produces an increased air pressure inside the box 18.

At the same time, each of the valves 30-38 is operated so as to connect the respective capture bag to the atmosphere. The effect of the increased air pressure inside the box is to cause any gas which may be inside the capture bags 20-28 to be evacuated to the atmosphere. In some circumstances the capture bags may be already evacuated in which case this step may be unnecessary.

Once smoking of the cigarette is to commence, the valves 30-3 8 are operated to connect the capture bags 20-28 to the respective flow controllers 40-48. The valve 50 is then operated so as to connect the vacuum generator 54 to the inside of the sealed box 18. The vacuum generator 54 is then started, which causes air to be removed from the sealed box 18. The reduced air pressure which is produced inside the sealed box 18 causes air to be drawn into the capture bags 20-28 under control of the respective flow controllers 30-38. The capture bags 20-28 thus inflate with the side stream smoke from the respective chimneys. The gases are collected automatically by the bags without going through a pump or other capture device thus minimising the risk of contamination.

At the conclusion of smoking the capture bags can be sealed. Bags can be emptied by opening valves to analysis or other devices and a flow of air allowed back into the box in which the bags are stored or the gas can be pumped out once atmospheric pressure has been restored within the box.

The speed at which inflation of the capture bags takes place is dependent upon the vacuum generator 54 and the flow controllers 40-48. During smoking of the cigarette, these devices are controlled so as to produce the required flow of air across the cigarettes. The flow controllers 4048 may be manual control devices, fixed constant flow orifices, or closed loop feedback flow control devices depending on the degree of sophistication demanded. A control unit may be provided to control the flow controllers and/or the vacuum generator.

In other embodiments of the invention there may be a multiplicity of valves between the chimney and bag to add additional functions such as evacuation of the bag or direction of the bag contents to a secondary analysis device.

Figure 3 shows parts of a side stream smoke capture device according to another embodiment. Parts which are in common with Figure 2 are given the same reference numerals and are not described again. Referring to Figure 3, flow control meter 60 measures the rate of flow of side stream smoke into the capture bag 20. The measured flow rate is fed to flow control unit 62, which adjusts the flow controller 40 and/or the vacuum generator 54 in dependence on the measured flow rate. In general, course control of the flow rate is effected by adjusting the vacuum generator 54, while fine control of the flow rate is effected by controlling the flow controller 62. Although only a single flow meter is shown in Figure 3, a separate flow meter may be provided for each of the capture bags 20-28 shown in Figure 2.

The valves 30-38 and 50 may be operated manually, or may be controlled automatically by a control unit, which may be the same as or separate from the flow control unit 62. For example, the valves 30-38, the flow controllers 40-48, the valve and the vacuum generator 54 may be operated automatically so as to capture the side stream smoke in a predetermined manner when a smoking article is smoked in a main stream smoking machine.

The present invention thus provides a simple method of drawing air across the surface of a cigarette and capturing this into a bag. Moreover this can be produced in one or many off variants with only minimal additions of parts allowing a cost effective solution for multiple smoking machines. Also the disclosed method provides a more uniform method of drawing air from the side stream into the collection bags.

The present invention is not limited to the capture of side stream smoke, but may be used in any situation where it is desired to capture smoke. For example, the present invention could be also be used to capture main stream smoke.

Claims

1. An apparatus for capturing smoke from a smoking article, the apparatus comprising: a capture bag having an opening for receiving the smoke; a sealed chamber in which the capture bag is located, the opening of the capture bag passing through the sealed chamber; and means for connecting the inside of the sealed chamber to a vacuum source, wherein the apparatus is arranged such that, when a reduced air pressure is applied to the inside of the sealed chamber by the vacuum source, the capture bag expands thereby drawing the smoke into the capture bag.

2. Apparatus according to any of the preceding claims, further comprising a flow controller connected to the opening of the capture bag.

3. Apparatus according to any of the preceding claims further comprising a control unit for adjusting the rate at which smoke is drawn into the capture bag.

4. Apparatus according to claim 3, wherein the control unit is arranged to adjust operation of the vacuum source.

5. Apparatus according to claim 3 or 4, wherein the control unit is arranged to adjust operation of a flow controller connected to the opening of the capture bag.

6. Apparatus according to any of claims 3 to 5, further comprising a flow meter, wherein the control unit is operable to adjust the rate at which smoke is drawn into the capture bag in dependence on an output of the flow meter.

7. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the capture bag to a smoke path.

8. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the capture bag to the atmosphere.

9. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the capture bag to an external device.

10. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the vacuum source to the inside of the sealed chamber.

11. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the inside of the sealed chamber to the atmosphere.

12. Apparatus according to any of the preceding claims, further comprising means for selectively connecting the inside of the sealed chamber to a source of compressed gas.

13. Apparatus according to any of claims 7 to 12, further comprising a control unit for automatically controlling operation of at least one of the selective connecting means so as to capture smoke in accordance with a predetermined smoking routine.

14. Apparatus according to any of the preceding claims wherein the apparatus is apparatus for capturing side stream smoke from the smoking article.

15. Apparatus according to any of the preceding claims further comprising a chimney for collecting the smoke to be captured.

16. Apparatus according to claim 15 wherein the chimney is located next to the smoking article in order to capture side stream smoke.

17. Apparatus according to any of the preceding claims comprising a plurality of capture bags located inside the sealed chamber for capturing smoke from a plurality of smoking articles.

18. An apparatus for capturing side stream smoke from a plurality of smoking articles, the apparatus comprising: a plurality of capture bags, each having an opening for receiving smoke from a respective smoking article; a sealed chamber in which the capture bags are located, the openings of the capture bags passing through the sealed chamber; and a connector for connecting the inside of the sealed chamber to a vacuum source, wherein the apparatus is arranged such that, when a reduced air pressure is applied to the inside of the sealed chamber by the vacuum source, the capture bags expand thereby drawing the smoke into the capture bags.

19. A smoking machine for main stream smoking of smoking articles, comprising an apparatus according to any of the preceding claims.

20. A method of capturing smoke in a capture bag, the capture bag being located inside a sealed chamber, the method comprising the steps of: smoking a smoking article; collecting smoke produced by the smoking article; connecting the capture bag to a path of the collected smoke; connecting the inside of the sealed chamber to a vacuum source; and applying a reduced air pressure to the inside of the sealed chamber by means of the vacuum source, thereby causing the capture bag to expand thereby drawing the smoke into the capture bag.

21. A method according to claim 20, further comprising the step of, before capturing the smoke, connecting the inside of the sealed chamber to a source of compressed gas so as to evacuate the capture bag.

22. Apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.

23. A method substantially as described herein with reference to the accompanying drawings.