GB2205222A

GB2205222A - Charging device for rod machines of the tobacco processing industry

Info

Publication number: GB2205222A
Application number: GB08808431A
Authority: GB
Inventors: Jan Jaremark
Original assignee: Koerber AG
Current assignee: Koerber AG
Priority date: 1987-04-09
Filing date: 1988-04-11
Publication date: 1988-12-07
Anticipated expiration: 2008-04-11
Also published as: DE3712046A1; IT1216552B; GB8808431D0; IT8820104A0; DE3712046C2; GB2205222B

Description

2205222 1.

CHARGING DEVICE FOR ROD MACHINES OF THE TOBACCO PROCESSING INDUSTRY.

The invention relates to a device for the simultaneous charging of a number 'of, tobacco processing rod machines with tobacco with pneumatic chargihg lines, which connect at least one charging supply with the charging. locks of the rod machines, with suction pipes connecting the charging locks of the rod machines to an exhaust air pipe, and with a low pressure source subjecting the suction pipes to low pressure by way of the exhaust air pipe.

In the present connection the term 'tobacco' is to be taken in the first instance to mean cut tobacco for charging cigarette rod machines. This designation is however also intended to cover shredded tobacco leaves, smokable tobacco substitutes and similar primary materials for the manufacture of smokable products. Loose, fibrous filter material for the manufacture of tobacco- smoking filters can also be supplied to appropriate filter rod machines by means of a device of this kind.

Devices of the said type are used to charge the distributors" of rod machines of the tobacco processing industry with tobacco from a supply, as uniformly as possible according to their needs. This involves keeping the level of tobacco in the distributor as constant as possible and avoiding the formation of lumps, so as to guarantee the formation of a tobacco rod which is as uniform as possible, with constant properties. For this it is also important for the consistency of the tobacco, the structure of its fibres, the fibre length, its mixture etc., to be maintained in a reproducible fashion during the pneumatic transportation from the W 41 i 2.

supply to the distributor of the machine.

For this purpose the setting and the maintenance of an optimum speed of the conveying air in the conveyor pipe are of great importance, on the one hand to ensure that the damaging effect of the conveying process on the tobacco consistency is minimal or to exclude it altogether, on the other hand however to meet the requirements of modern rod machines with their high throughput of tobacco. so far as the output of the pneumatic conveying system is concerned.

Charging devices of the type described at the outset are known per le. They are generally designed so as to be able to charge a number of rod machines with tobacco simultaneously from a shared charging supply by means of separate charging lines. With these devices the conveying air, after it has been separated from tobacco in the charging lock of a rod machine, passes through a collecting pipe common to all machines into a dust separator, and to the low pressure source which produces the current of air required to convey the tobacco pneumatically. As soon as a rod machine signals a need, the appropriate charging line is placed under low pressure so that tobacco is sucked out of the charging supply and conveyed to the charging lock of the rod machine. When the charging lock is full, the appropriate charging line is closed again. This can also happen to a number of rod machines or all rod machines simultaneously. In order on the one hand to avoid operating the low pressure source, normally a fan, for a short time on each occasion, if the number of machines currently being charged should change, whilst on the other hand maintaining the optimum air velocity in the charging lines. if the machines v 1 -1 3.

currently being charged should change, in the known charging device a secondary air intake is provided in the collecting pipe flue, which intake is opened to a greater or lesser degree depending on the number of machines being charged at that moment. The intention is to keep the balance of air in the pipe system as constnt as possible by this means, so that the air velocity In the charging lines also remains the same as far as possible.

However it has emerged that the disconnection and connection of charging lines in response to corresponding signals of need from the rod machines nevertheless affects the pressure in the pipe system and thus affects the conveying speed in the charging lines.

The object of the invention is therefore further to improve a charging device of the type described at the outset. In particular effects on the conveying process in the charging lines when other charging lines are disconnected and connected are to be excluded so far as possible.

This object is achieved with a device of the type described at the outset according to the invention in that all tobacco separators are connected by separate suction pipes to a shared junction area. Therefore the charging locks of the tobacco separators assigned to the machines to be supplied with tobacco by means of the pneumatic charging device no longer open in stages one behind the other into a collecting pipe, - but are connected by means of separate suction pipes directly to the shared junction area and the exhaust pipe connected thereto. The dust separator can be provided as a junction area of the suction pipe. In -a continuation of the invention, measuring and control means are 1 101 4.

provided for keeping the pressure constant in the junction area.

For this purpose according to the invention a pressure measuring means can be arranged at an appropriate point in the flue of the exhaust air pipe,. to record the air pressure in the exhaust air pipe hnd thereby also in the junction area. As the pressure in the junction area is directly decisive so far as the pressure conditions in the suction pipes are concerned, the pressure measuring means is preferably arranged in the junction area itself. As a control means for keeping the pressure constant in the junction area a secondary air intake can be provided, adjustable according to the pressure measured in the junction room or in the exhaust air pipe. An adjustable throttle valve can also serve as control mea-ns according to the invention. According to the invention the dust separator is integrated into the exhaust air pipe, and connected by way of a purified air line to the low pressure source. The control means can be assigned to the purified air pipe so that the latter in this embodiment of the invention is provided with an adjustable secondary air intake or/and has a controllable throttle valve. According to a preferred embodiment of the Invention. a throttle valve is arranged in the offtake pipe of the ventilator that serves as a low pressure source. If a controllable throttle valve is provided as control means, a ventilator, preferably with a flat characteristic curve, is employed as a low pressure source. This junction area can be kept constant even where the quantity of conveyed air is changed, by adjusting the throttle valve in the purified air pipe.

The device according to the invention has the advantage that it permits a very reliable charging of 1 1 1 1 5.

the connected rod machines with tobacco from a central charging supply. In this way optimum conveying speeds for the tobacco are obtained in the charging lines, so that mixture and consistency of the tobacco when charging vary as little as possible. The further advantage of the invention helps considerably$, in that the conveying speed in the charging lines is not affected when other charging lines,are connected and disconnected.

The invention will now be explained in more detail with reference to the drawing. The figure shows a top pl'an view of a device according to the invention, in diagrammatic form.

The drawing shows a diagrammatic plan view of three cigarette rod machines la, lb and lc, which are supplied with tobacco by means of a charging device according to the invention, by way of charging lines 2a-c from a central charging supply 3, in response to a demand signal. The charging supply 3 is kept ready in a charger 4, for example of the type KAB of the Applicant. Separate charging lines 2a-c connect the charger 4 with the tobacco separators 6a-cr which are arranged in front of charging locks, not shown, of the cigarette rod machines la-c.

The tobacco separators 6a-c are connected to a junction area 15 and an exhaust air pipe 5 by way of separate suction pipes 7a-c. The exhaust air pipe 5 contains a dust separator 8. which is connected to the suction side of a blower 11 by way of a purified air pipe 9. Between the junction area 15 and the dust separator 8 there is an exhaust air pipe section 21 acting as a connection. This can be dispensed with, if the junction area 15 is connected directly to the dust separator 8. The suction pipes 7a-c can be closed, or opened in case of need, by means of 6.

throttle valves 12a-c controlled by actuators 10a-c.

Further suction pipes 7 and charging lines 2 are connected to additional rod machines,, which are not represented in the drawing for reasons of simplicity.

The junction area 15 is equipped with a pressure measuring device 13. A throttle valve 14 is in thd offtake pipe 22,, the setting of which valve determines the quantity of air flowing through the exhaust air pipe and the offtake pipe. 16 denotes an actuator for the throttle valve 14,, which actuator is controllable according to the pressure recorded by the pressure measuring:device 13, and adjusts the throttle valve 14 according to the pressure measured in the junction area 15, this arrangement making it possible to keep the pressure constant in the exhaust air pipe 5, the dust separator 8 and the junction area 15.

In operation the blower 11 produces low pressure in the exhaust air pipe 5. i.e. in the purified air pipe 9, the dust separator 8, the exhaust air pipe section 21, the junction area 15 and the suction pipes 7 and 7a-c. If in response to a demand signal from one of the rod machines one of the throttle valves 12a-c, for instance throttle valve 12cp is opened. a current of air is created in the appropriate charging line 2c,, with which tobacco is sucked in from the charging supply 3 and conveyed into the tobacco separator 6c. The conveying air separated from the tobacco flows through the suction pipe 7c to the junction area 15,. and by way of the exhaust air pipe section 21 to the dust separator 8, where any dust particles contained in the air are separated out, and it is then drawn away by the purified air pipe 9 of the blower 11. When the throttle valve 12c of the suction pipe 7c is opened, 1 7.

the pressure monitoring device in the junction area 15 shows a reduction in the pressure -and, by way of an actuator 16, causes a further opening of the throttle valve 14r so that the pressure in the junction area 15 again resumes the value set. Accordingly when further charging lines 2 are connedted by opening further throttle vaives 12# the throttle valve 14 is again opened in the purified air pipe. so that the pressure in the junction area 15 remains constant.

As soon as sufficient tobacco reaches the tobacco separators 6a-6c of a cigarette rod machine, the relevant throttle valve 12a-12c is closed again. This causes the pressure in the junction area 15 to rise, and the throttle valve 14 is closed more accordingly. by way of the actuator 16.

This concept of the charging device for a number of cigarette rod machines thus guarantees that the conveying speed in the charging lines 2 and 2a-c can be kept at an optimum value, and that the connection or disconnection of individual charging lines by means of the throttle valves 14 does not affect the conveying process in the other charging lines.

In place of a throttle valve 14 or in addition to it, a secondary air intake 17 can also be provided in the purified air pipe 9. the crosssection of which intake is adjustable by means of an adjustable throttle valve 18. The throttle valve 18 is adjustable by means of an actuator 19. which actuator is connected to the pressure measuring device 13. This is indicated by a broken line in the drawing. If one or more of the throttle valves 12a-c are opened, whereby the pressure in the dust separator 8 drops, the throttle valve 18 of the secondary air intake is closed more accordingly, whereby the 1 8.

pressure in the junction area 15 is kept constant at its set value. Conversely when charging lines 2 are disconnected, the throttle valve 18 is opened wider, so that the pressure in the junction area 15 is maintained.

A filter unit marketed by the Applicant can be used a:s a dust separator 8. A ventilator with a fla: t characteristic curve is particularly suitable as a blower 11, which ventilator guarantees a constant pressure in the dust separator 8, even when the settings of the throttle valve 14 are changed.

The throttle valve 14 or/and the controllable' secondary air intake 17 can also be located at another point in the exhaust air pipe 5, for example between the junction area 15 and the dust separator 8. The arrangement shown is however preferred, because the function of this control means in the purified air pipe 9 is not adversely affected by dust or other articles carried along in the current of air.

Likewise the pressure measuring means 13 can also be arranged in the area of the dust separator 8 or at another point in the flue of the exhaust air pipe 5,, because the pressure in these sections of the exhaust air system is proportionate to the pressure in the junction area,, if not actually identical with it.

As the drawing shows,, an adjustable throttle 23 is provided for the suction pipe 7b. This is shown as representative of like throttles in. all suction pipes 7, 7a-c. With the throttles 23 the line resistances of all pipes 7, 7a-c can be adjusted to one another so as to be the same in all suction pipes, and thus so that the reduction in pressure is the same in all suction pipes.

Q 0 1.v 41 I -1 r 9.

Claims

CLAIMS:

1. Apparatus for simultaneously charging a plurality of tobacco processing rod machines with tobacco, comprising pneumatic charging line. s which connect at least one charging supply to the tobacco separators of the rod machines, separate suction lines connecting the tobacco separators of the rod machines to an exhaust air line by way of a manifold and a low pressure source subjecting the suction lines to low pressure by way of the exhaust air line.

2. Apparatus as claimed in claim 1. wherein the exhaust air line has a dust separator adapted' to provide said manifold.

3. Apparatus as claimed in claim 1 or 2, wherein measuring and control means are provided to keep the pressure in the manifold constant.

4. Apparatus as claimed in any one of claims 1 to 3, wherein the manifold has pressure measuring means for recording the air pressure therein.

5. Apparatus as claimed in any one of claims 1 to 4, wherein a secondary air intake, adjustable according to the manifold pressure, is provided as control means for keeping the pressure in the manifold constant.

6 Apparatus as claimed in any one of claims 1 to 5,, wherein a throttle valve, adjustable according to the pressure in the manifold, is provided as a control means.

7. Apparatus as claimed in any one of claims 2 to 6, wherein the dust separator is integrated into the exhaust air line and is connected by means of a purified air line to the low pressure source, and the control means is provided on the pu.-ified-air line.

8. Apparatus as claimed in any one of claims 1 f 10.

to 7, wherein the control means is provided on the offtake pipe of the ventilator serving as a low pressure source.

9. Apparatus as claimed in any one of claims 1 to 8, wherein a ventilator with a flat characteristic curve is used as a low pressure source.

I. 0. Apparatus as claimed in any one of claims 1 to 91 wherein adjustable throttles are provided in the separate suction lines to adjust the line resistances.

11. Apparatus for simultaneously charging a plurality of tobacco processing rod machines with tobacco, substantially as herein described with reference to-the accompanying drawing.

11 Published 1988 at The Patent Office, State House, 66171 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.