WO1992002787A1

WO1992002787A1 - Process and device for the metered filling of containers with pourable media

Info

Publication number: WO1992002787A1
Application number: PCT/DE1991/000637
Authority: WO
Inventors: Wolfgang Schröder
Original assignee: Schroeder Wolfgang
Priority date: 1990-08-07
Filing date: 1991-08-06
Publication date: 1992-02-20
Also published as: DD297123B5

Abstract

The invention relates to a process and device for the conveying-current controlled, viscosity-independent and metered filling of containers with pourable media. According to the invention, the time taken to fill the volume of a filler pipe is measured and compared with the volume of a container to be filled in a time-determined ratio. The invention concerns a device in the filler pipe (7) of which a filling medium is measured between sensors (5; 6; 16; 17) and taken into the volume of a container via a control device (8) in a time-quantity ratio.

Description

Method and device for filling volume-flowable media into vessels

The invention relates to a method for the flow-controlled, viscosity-independent and volume-metered filling of flowable media into vessels and a device for carrying out the method.

It is known that in the case of conveying-flow-controlled filling machines, the conveying flow is generated with low energy expenditure and the frictional resistance is reduced by avoiding cross-sectional constrictions in the line and conveying system. This is achieved in that a centrifugal pump is arranged in the filling material in an automatically level-controlled filling material container, which is connected to a supply line for the product import, on the pressure side of which there is an ascending filling tube. The filler tube has a shape that enables it to be filled almost without dripping.

The disadvantage of this feed rate-controlled filling machine is its time-dependent filling programs. The time dependence of filling, i.e. H. The pre-setting of the filling time leads to dosing errors in the case of already slight fluctuations in the viscosity, which have to be corrected either by constant adjustment of the filling time or by an additionally integrated scale, with the aid of which the filled quantities for the following vessels are corrected. After the filling has been interrupted, after breaks in the case of a change of product and container size, the complex adjustment of the time program begins again until the required quantities are set again.

The invention has for its object a method and a device for the flow-controlled, viscosity-independent and volume-metered pouring of flowable media into vessels with which, by means of continuous compensation of viscosity influences and non-contact measurement of a comparative volume, a precisely volume-filled filling of the vessels takes place, which furthermore results in the utility properties of the device, especially in relation to one high dosing accuracy can be improved taking into account the existing properties of the media.

According to the invention, the object is achieved in that the time for filling the volume of a filling tube is measured and brought into a time-determined relationship in comparison with the volume of a vessel.

It is in the sense of the invention that the time, divided as a time unit for filling the filling tube, is set starting at the start of filling and ending when the medium exits the filling tube.

The invention is designed in that the base for filling the volume of the filling pipe by an overflow arrangement

Level container is always kept constant, whereby according to a form of the invention, the time units are classified as time cycles.

The invention is visibly further developed in that the quotient of the vessel volume and filling tube volume is multiplied by the time cycles and the filling volume is thus determined. The total volume of a filling is determined according to the invention from the quotient of the container and filling tube volume multiplied by the time intervals for filling the filling tube volume. One embodiment of the invention is when the viscosity is determined in a calibration tube arranged separately and parallel to the filling tube. All movement processes of the vessels are detected by the position sensor and the measuring processes of the control signal in the control device, arranged and output in a controlled manner via the output signal. The invention is formed in that a level container is arranged in a buffer container. This is connected to a pump by a pipe. A centrifugal pump with an ascending filling pipe, which projects out of the buffer tank, was arranged in the level tank. Another pump arranged outside the level container at the bottom of the buffer container ensures a constant filling level by constantly overfilling the level container. As a result, the filling medium in the buffer container is kept in a constant cycle at the same time. At the protruding end of the filling tube, a barrier formed by sensors is provided, which is connected to a control device via a control signal. The barrier is provided in front of a switching amplifier by means of an output signal and is connected in an amplifying manner to the pump, the control device being operatively connected to a position sensor via a control signal. The pump in the buffer tank is connected to the level tank on the pressure side. Your suction side protrudes into the buffer tank. As a result, in one embodiment of the invention, the circuit of the filling medium is provided over the upper edge of the level container and the pressure side of the pump.

According to a further embodiment of the invention, the control signal of the position sensor and the control signal of the light barrier are connected with the control device at different times, reacting one after the other.

One form of practice is that two sensors are arranged one above the other in the filling tube in a certain section, a certain filling volume being determined at the same time by the section between the two sensors.

Another form of the invention is designed so that in the filling tube a sensor is arranged and is operatively connected to the sensor at the outlet of the filling tube, wherein in an arrangement variant of the invention the sensor in the filling tube is arranged above the level of the medium in the level container.

The solution according to the invention has the advantage of assigning a level container in a filling container with controlled product supply, which is filled by a centrifugal pump arranged in the filling container. The level container in which the metering pump is arranged overflows constantly. The metering pump, advantageously a centrifugal pump, is connected on its pressure side to an ascending filling tube, which is designed in such a way that its surfaces pointing downwards at the spout are shorter than the front edge of the filling tube, the surfaces always pointing upwards having. As a result, material residues running down are always returned from the lower edge of the spout of the filling tube into the filling tube, and dripping is largely avoided.

Due to the even overflow of the level container with the centrifugal pump arranged therein, the filling start advantageously takes place constantly from the same level. If the filling tube volume is measured and used as a standard, it is only necessary to exactly record the filling start and the filling outlet.

The time between a filling start and a product discharge is saved. This advantageously records the volume that passes through the filling tube in a certain time.

If, according to the procedure, the number of times the filling tube volume has to be emptied into the vessel to be filled has been entered into the control system, then it is only necessary to enter the corresponding multiplier during the actual dosing. The time that passes between the start of filling and the discharge of the filling material from the filling tube, recorded exactly and multiplied by the previously entered setpoint value. The filling flow-controlled filling process is thus independent of the preset time.

If media of different viscosities are filled in practical operation, then no adjustment is necessary. If, during the filling of products, their viscosity changes depending on the temperature, these temperature changes no longer have any influence on the dosing accuracy. The flow-controlled device is thus advantageously independent of preset times for dosing. If media of different and changing viscosity are filled, it is no longer necessary to adjust the filling time.

The invention will be explained in more detail using an exemplary embodiment.

In the accompanying drawing:

1: the device in a schematic representation;

2: the flow diagram of the procedural steps;

Fig. 3: the design and arrangement of the buffer tank;

Fig. 4: another embodiment of the arrangement for measuring the filling time: the filling pipe.

The device has a buffer container 12 for receiving tixotropic media, in which a level container 11 is arranged. In the buffer tank 12 there is an overflow upstream of the level tank 11. running pump 4 provided. The level container 11 also has a metering pump 3, to which a filling pipe 7 is adapted. This filling tube 7 rises at the metering pump 3 and is designed at the outlet so that the downward-facing surfaces of the outlet are shorter than the front lower edge of the filling tube 7, which always has upward-facing surfaces.

The grommet 14 of the filling tube 7 is operatively connected to the light beam from a light transmitter 5, the beam of which is accepted by a light receiver 6, which is connected to a control device 8 and receives the control signals 13 of the light receiver 6. A position sensor 10 is arranged on a conveyor belt, not shown, and is likewise brought into an operative connection with the control device 8 via a control signal 9, the control device 8 being connected to a switching amplifier 1 via an output signal 2. The switching amplifier 1 is sensitized by the control signal 2 and connected directly to the metering pump 3.

The design of the outlet of the filling pipe 7 in the spout area is explained for the functional process. The spout 14 of the filling pipe 7 is designed in accordance with the requirements of non-dripping filling. The inclination of the spout bottom is designed to be slightly different from the vertical filling pipe 7. The spout bottom protrudes and the further spout area is designed to flee backwards. Due to the steep spout bottom protruding from the spout area, filling medium remaining in the filling pipe 7 does not run out of the spout 14 but back into the filling pipe 7.

Furthermore, the functional classification of the sensors 5; 6 shown in the area of the spout 14. At the outlet end of the filling tube 7 is horizontally z. B. a light barrier, consisting of sensors 5; 6, which are arranged as a light transmitter and receiver. The beam path from sensor 5 to sensor 6 runs in front of the filling tube and is set up in such a way that sensor 6 is covered when the filling material emerges from the filling tube. By darkening the light receiver, the cycle counter that was started at the start of filling is stopped and the determined cycles are stored in the control device. The total filling time t _{n is} determined in the control device from the determined cycles for filling the filling tube 7, which corresponds to a precisely known volume Vp and the entered vessel volume Vg. It is determined in the control device 8 how often the counted cycles for filling the filling tube have to be repeated in order to fill the entered vessel volume. In the case of products in which special accuracy is important, the time correction Kp, that is to say the time which elapses until the delivery speed of the metering pump 3, has to be subtracted from the counted cycles before they are processed in the control device 8. This time correction Kp is a constant variable.

As a basis for exact compliance with the sensors 5; 6 fixed time-quantity ratio, the arrangement of the buffer container 12 shown in FIG. 3 is provided. Through a feed pipe 15, the filling medium is fed into the buffer container 12, which fills it up to a filling level to be shown in more detail. A level tank 11 is fastened to the bottom of the buffer tank 12 and a pump 4 connected to it by a tube is provided, which pumps the medium in the level tank 11. The level container 11 has a lower height than the buffer container 12 and is filled by the pump 4 so that the filling medium from the level container 11 constantly overflows. This means that the same initial level of the filling medium is constantly present for the pump 3 located in the level container 11 and uniform dosing is possible. The pump 3 delivers after a switching pulse of the switching amplifier 1 the filling medium up through the filling pipe to the spout 14.

At the beginning of the process, the position sensor 10 sends a control signal 9 to the control device 8. The position sensor 10 is located in the region of a conveyor belt (not shown) which is filled with containers. A second control signal, not shown, causes the conveyor belt to stop. The control device 8 issues a control command to the switching amplifier 1. The metering pump 3 is controlled directly by the switching amplifier 1. The filling start "metering pump 3 on" is detected by simultaneously starting a counter integrated in the control device 8.

If the filling beam emerges from the spout 14 of the filling pipe 7, the light beam between the sensors 5; 6 interrupted. The counted bars, corresponding to a certain time, are saved. From the determined time, an independent total time necessary for filling the container is determined in the control device 8. The total time for filling the vessel is based on the formula

(ti - K _F )

VF

calculated. Are there

VQ = vascular volume

Vp = filling tube volume

t ^ = filling time of the filling pipe

Kp = correction time - time that passes until the filling pump delivers medium t _n = total filling time

After the total filling time t _n , the control command 2 is canceled by the control device 8. The switching amplifier 1 switches off the metering pump 3. The conveyor belt is started and a newly arriving vessel can be filled again. So that the volume of the filling tube 7 does not change, the level container 11 is arranged in the buffer container 12. The level container 11 is constantly filled by the overflow pump 4 so that it overflows. The level in the buffer tank 12 is regulated by a level control (not shown), which in the simplest case can be a float control, in such a way that the level in the buffer tank 12 is always lower than the level of the level tank 11 Dosing pump 3 always promotes from the same starting level. Another advantage of this arrangement when filling tixotropic media is that the constant filling of the level container 11 means that the tixotropy is completely broken down, even when the vessels are not continuously filled. This means that there is no different filling quantity for the first vessel to be filled, which can be caused by the fact that after the start of filling, the high viscosity of the tixotropic medium has to be reduced by the movement up to a substantially lower amount of the viscosity. This also ensures that the correction factor Kp (time that elapses after the filling pump starts to fill up to the effective speed) remains constant. For each filling, the total filling time is newly determined in the control device 8 after the filling pipe time t ^ has been saved. For filling larger or smaller vessels, it is therefore only necessary to enter the change in the vessel size into the control device. Varying viscosities, such as occur particularly in media whose viscosity is highly temperature-dependent, have no influence on the metering accuracy.

If the level in the level container 11 cannot be kept constant, then the total filling time for the filling tube is not measured exactly. In another embodiment according to FIG. 4, two sensors 16; 17 arranged one above the other, which detect the passage of the product front in the filling pipe between the two sensors. From the distance between the sensors and the cross-sectional area of the filling tube, the filling flow is determined in the control device 8 and from this the filling time for the vessel to be filled is determined according to the type of filling already described.

The sensors 5; 6 designed as a light transmitter and receiver are arranged horizontally. This prevents filling material from possibly dripping out of the filling pipe to contaminate the sensors 5; 6 leads. These sensors are expediently arranged in such a way that the beam path between the light transmitter and the light receiver runs without a recognizable distance from the spout end. Instead of the sensor 5 designed as a light transmitter and receiver; 6, a capacitive proximity sensor can also be used, which detects the media outlet directly on the spout connector. After the start of the filling program, which is triggered by the presence of a container, media are filled that have no tixotropic properties and do not tend to settle or separate. If the level is kept constant by constantly filling the level container 11, if, according to FIG. 4, two sensors 16; 17 are arranged one above the other, which detect the passage of the product front in the filling tube 7 between the two sensors.

According to this variant, the distance between the sensors 16; 17 from each other and the cross-sectional areas of the filling tube 7 in the control device 8 from the chronological sequence of the signal from the sensors 16; 17 the volume flow is determined and from this the filling time t _n for the vessel to be filled is determined in accordance with the embodiment already described.

In another embodiment, the control device 8 is only started when the pump is already pumping. Here, only one sensor 16 is arranged above the liquid level of the level container 11. The incoming filling material is started by the sensor 16, the counter integrated in the control device 8 and by interrupting the beam path between the sensors 5; 6 the clock counter is stopped and the determined clocks are stored in the control device.

The total filling time is determined in the control device from the ascertained cycles for filling the filling pipe section, which corresponds to a precisely determined volume, and the entered vessel volume. In this version, the total time for filling the vessel is calculated according to the formula

t _n =. _tl

V

calculated.

In this embodiment, it is not necessary to set the correction time Kp from the counted cycles, since the sensor 16 is sensitized by the incoming flow generated.

In this embodiment, the sensor 16 triggers the feed flow generated by the metering pump 3 and is connected to the sensors 5; 6 in an operative connection via the control device 8. List of the reference symbols used

Kp time correction

Claims

1. Process for the flow-controlled, viscosity-independent and volume-metered filling of flowable media into vessels, characterized in that the time for filling the volume of a filling tube is measured and brought into a time-determined relationship in the set comparison with the volume of a vessel to be filled.

2. The method for claim 1, characterized in that the time for filling the filling tube is divided into time units starting at the start of filling and is ended when the medium emerges from the filling tube.

3. The method according to claim 1, characterized in that the base for filling the volume of the filling tube is always kept constant by an overflow arrangement of a level container.

4. The method according to claim 2, characterized in that the Zeit¬ units are classified as a time file.

5. The method according to claims 1, 2 and 4, characterized in that the quotient of the vessel volume and filling tube volume is multiplied by the time files and determines the filling quantity.

6. The method according to claim 1 to 5, characterized in that the total volume of a filling is determined from the quotient of the Füllrohr¬ volume and the timing.

7. The method according to claim 1 and 2, characterized in that the determination of the viscosity is carried out separately outside the filling tube. - 14 -

8. The method according to claim 1 to 6, characterized in that the Bewegungsvorgäπge the vessels of the Positionsseπsor and the Meß- voräπge the control signal in the control device is detected, ge¬ and output regulated via the output signal.

9. Device for the metered pouring of flowable media into vessels, which has a device for setting up and moving vessels and filling and metering devices, characterized in that a filling tube (7) protrudes from a buffer container (12), in which a level container (11) is arranged, in which the filling pipe (7) is connected to a pump (3), ends in a filling media bath, the level container (12) having a common filling media bath, which is achieved by uniformly overfilling the level container (11) is kept in a continuous circulation with the filling medium and a barrier formed by sensors (5; 6) is provided at the projecting end of the filling tube (7), which barrier is provided with a control via a control signal (13) ¬ direction (8) is connected, which is provided via an output signal (2) in front of a switching amplifier (1) and is connected in an amplifying manner to the pump (3), the control valve device (8) with a position sensor (10) via a control signal (9) is in an active connection.

10. Device according to claim 9, characterized in that the level container (11) is arranged in the buffer container and the pump

(4) a constant circuit is connected on the pressure side to the level tank (11) and on the suction side to the buffer tank (12).

11. The device according to claim 9 and 10, characterized in that the circuit of the filling medium over the upper edge of the level container

(11) and the pressure side of the pump (4) is provided.

12. The device according to claim 9, characterized in that the control signal (9) of the position sensor (10) and the control signal (13) of the light barrier with the sensors (5; 6) in a time-delayed manner interacting interactively connected to the control device (8) are.

13. The device according to claim 9, characterized in that in the Füll¬ tube (7) in a certain section (18) two sensors (16; 17) are arranged one above the other.

14. Device according to claim 12, characterized in that a certain filling volume is defined by the section (18) between the sensors (16; 17).

15. Device according to claim 9 and 12, characterized in that a calibration tube is arranged parallel to the filling tube (7) to determine the viscosity of the medium.

16. The device according to claim 9, characterized in that a sensor (16) is arranged in the filling tube (7) and is in operative connection with the sensors (5; 6).

17. The device according to claim 16, characterized in that the sensor (16) above the level of the medium in the level container (11) is arranged.