EP1371895A2

EP1371895A2 - Process and apparatus for filling bottles with gas

Info

Publication number: EP1371895A2
Application number: EP03384001A
Authority: EP
Inventors: Pedro Saura Noguera; Luis Alfonso Monge Sanz
Original assignee: Sociedad Espanola de Carburos Metalicas SA
Current assignee: Carburos Metalicos SA
Priority date: 2002-05-16
Filing date: 2003-05-15
Publication date: 2003-12-17
Also published as: EP1371895A3; ES2211285B1; ES2211285A1

Abstract

Characterised in that the apparatus comprises a turner (1) on which the bottles (2,3,4) are placed, an actuator that causes the turner (1) to swivel, a pneumatic circuit that connects the aforesaid bottles (2,3,4) to a gas tank, pneumatic means (7 to 21) provided in said circuit for carrying out the venting, washing, vacuumising and filling operations, and control means that act on the actuator and on the pneumatic means (7 to 21) so as to permit automatic control of said operations. Filling of the bottles with gas is controlled by means of a mass flow meter. The gas can thus be dispensed into the bottles without removing them from the turner, thereby reducing the number of operations to be carried out for each bottle, and ensuring the quality of the bottled gas.

Description

This invention relates to a process for filling bottles with gas and an apparatus for carrying out that process.

BACKGROUND OF THE INVENTION

Processes are known in the art for filling containers or bottles with gas, such as CO₂, which basically comprise the following stages:

Emptying and washing the containers by depressurising them.
Filling the bottles with the gas, controlling the mass flow using scales.

The container depressurisation stage before starting filling ensures that the gas in the containers is emptied.
It is nevertheless possible for some kind of residue in liquid phase to remain inside the containers, and this cannot be removed simply by depressurising the container nor by vacuumising the bottle.
The presence of some kind of residue can lead to the following problems:

Overfilling of containers: The quantity of CO₂ put into the bottles is calculated to take account of their geometric capacity. If the receptacle is not completely empty, however, the CO₂ dispensing overfills the container with the attendant safety risk and possible loss of product, while the tap relief disc may even burst.
Contamination of the product dispensed into the containers: Even if the quality of the CO₂ lies within the specifications, the product may become contaminated if the container is not clean enough.
Shorter useful life of the container: Certain contaminants such as moisture, while not harmful for human consumption, have a highly damaging effect on the bottle, since CO₂ in the presence of water can form carbonic acid and contribute towards corrosion of the container interior.
Customer complaints, safety and liability: The foregoing can have a detrimental effect on the quality of the product supplied by the distribution company, as well as affecting its image.

Such processes likewise entail a number of disadvantages:
On the one hand, it is not feasible to empty the containers keeping them in their usage position, that is, vertical with the tap at the upper part.
To carry out the emptying properly the containers have to be inverted so that the remaining liquid can be removed.
For this purpose it is advisable to use a swivelling support or turner that allows the containers to be inverted safety and the residual product eliminated. The use of turners is known in various filling/packaging plants for recovering the residue in refrigerant containers.
On the other hand, placing bottles in a turner, emptying them, repressurising them, depressurising them, vacuumising them, etc., involves an increase in the number of operations to be carried out on each bottle. If in addition to this the bottles have to be removed from the turner and taken to the weighing scales the cycle time increases considerably.
The right solution would be to dispense the product into the bottles without removing them from the turner.
One way of dispensing the products into the containers is by using a mass flow meter.
Patent GB 2127533 relates to a device for filling bottles with a predetermined mass of compressed gas which can be in gaseous or liquid state, which device comprises a pump for the compressed gas, a mass flow meter which measures the mass flow per unit of time and emits a signal to show the quantity of compressed gas mass flow, and a control device which checks the flow of the mass flow meter, in such a way that said control device closes a filling valve and opens an outlet valve when a predetermined quantity is reached which is directly proportional to a suitable mass of compressed gas.
Finally, in spite of the saving of time involved in filling directly on the turner, the filling time remains considerable due to the number of valve movements being very high, since the system is not automated.

DESCRIPTION OF THE INVENTION

The objective of the process and apparatus of the invention for filling bottles with gas is to solve the disadvantages presented by the processes and apparatuses known in the art for filling bottles with gas, while providing a number of advantages which are set out below.
The process of the invention is characterised in that it comprises the following stages:
a) Placing the bottles on a swivelling support or turner.
b) Emptying the bottles of their previous content by making the turner swivel until the bottles rest in an inverted position.
c) Making the turner swivel again until the bottles are in the filling position.
d) Filling the bottles with gas, whereby filling is controlled by means of a mass flow meter.
This process thus ensures correct emptying of the bottles, eliminating solid and liquid residues. It therefore guarantees the quality of the bottled gas and correct dispensing of gas into the bottles.
Moreover, thanks to the use of the mass flow meter the gas can be dispensed into the bottles without taking them off the turner, which means that the number of operations to be carried out for each bottle is reduced.
Furthermore, the reliability of product dispensing offered by weighing scales is retained. Dispensing differences between scales and the mass flow meter are lower than 2%.
Filling times are likewise unchanged, so that increased product quality assurance does not have a detrimental effect on productivity.
Advantageously, after stage b) a venting and washing or washing off operation of the bottles is carried out.
Washing with CO₂ is found to be effective for eliminating gas-phase residues and also liquid residues, as long as their viscosity is not very high.
Preferably, after the washing or washing off, vacuum is applied and the collector is emptied.
The effect of elimination of moisture from the inside of the bottles by scavenging/washing with CO₂ followed by a vacuumising process is beneficial. The lower moisture level prevents the formation of carbonic acid and therefore lengthens the useful life of the bottles by reducing corrosion inside them.
Preferably, filling of the bottles placed in a single turner is carried out sequentially.
Optionally, the washing can be repeated a plurality of times.
The apparatus of the invention for carrying out the process for filling bottles with gas is characterised in that it comprises a turner in which the bottles are placed, and an actuator that causes the turner to swivel, a pneumatic circuit that connects said bottles to a gas tank, pneumatic means provided in said circuit for carrying out the operations of venting, washing, vacuumizing and filling, and control means that work upon the actuator and upon the pneumatic means so as to permit automatic control of said operations.
Advantageously, the turner comprises a swivelling structure, securing means for the bottles to said structure, means for activating said securing means, and lifting means of the bottles.
Said turner allows the bottles to be inverted without the operative having to make an extra effort. Once they are in the inverted position the various operations such as emptying and washing, among others, can be carried out.
Preferably, the securing means of the bottles are grips.
Preferably, the activation means are pneumatic pistons.
Advantageously, the pneumatic means include a vacuum pump, a vacuum tank, a plurality of valves, a plurality of pressure transmitters, and at least one mass flow meter.
Also advantageously, the control means include an interface for supervising the process and intervening in it, and a control system for execution of the programs.
Preferably, the interface includes a display screen.
Said display screen makes it possible to show the entire filling circuit and the elements that play a part in the process.
Advantageously, the control means comprise a plurality of control sequence modules, such as a test sequence module, a venting sequence module, a washing sequence module, a vacuum sequence module, a collector sequence module, a filling sequence module for each bottle, and a drainage sequence module.
Additionally, the control means include a series of alarms that indicate eventual process, instrumentation and system breakdowns.
It is thereby possible to identify rapidly any breakdown in the installation, so as to be able to find a suitable solution.
Advantageously, the alarms appear on the display screen.
Preferably, the control means permit the building of graphics for displaying data in real time.
Graphics of trends can therefore be created for presenting the process data being saved in the interface. It is also possible to examine how the process is working at any given time.
According to another embodiment of the invention, the apparatus includes a second turner.
An increase in the number of bottles filled by an operative in the course of one hour is obtained thereby.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate the description of all that has been set out above some drawings are attached which show, schematically and solely by way of non-restrictive example, a practical case of embodiment of the process and of the apparatus of the invention for filling bottles with gas, in which:
Figure 1 is a schematic diagram of the apparatus for filling bottles with CO₂ gas, using a single turner with capacity for three bottles; and
Figure 2 is a schematic diagram of the apparatus for filling bottles with CO₂ gas, using two turners, each one with capacity for three bottles.

DESCRIPTION OF A PREFERRED EMBODIMENT

As Figure 1 shows, the apparatus comprises a turner 1 with capacity for three bottles 2, 3, 4, actuated by a motor, which permits the bottles 2, 3, 4 to be placed in inverted position for venting, washing and vacuumising them, and for replacing the bottles 2, 3, 4 in their initial position for filling them, pneumatic means 7 to 21 for carrying out the aforesaid operations, and control means that allow said operations to be controlled automatically by means of a specific computer program.
The turner 1 comprises a swivelling structure onto which the bottles 2, 3, 4 are secured by means of a mechanism of grips 5 driven by pneumatic pistons, an electric motor with a transmission system, and a lifting platform 6 for the bottles 2, 3, 4.
The turner 1 permits the bottles 2, 3, 4 to be inverted without the operative having to make extra effort.
The pneumatic means 7 to 21 comprise the following instruments:

Pressure transmitters: Permit a pressure reading to be taken of a conduit, transmitting an electrical signal to the control system. Their purpose is to communicate to control means the pressures in the various areas of the apparatus and the activation of different computer program sequences and subsequences.
All-or-nothing valves: These control the flow in a conduit and allow of two possible positions: full flow circulation or no flow circulation. Said all-or-nothing valves are fitted in the draining and venting collectors, as well as in the product-input collector, and have the function of allowing CO₂ flow to pass as required by the control system.
Proportional valves: These control the flow in a conduit by permitting flow regulation in relation to some physical parameter such as pressure, flow-rate, etc. These proportional valves regulate the passage of CO₂ to achieve better final dispensing of the product.
Mass flow meter: Permits measurement of the mass flow (unit of mass/unit of time) passing through a conduit. This instrument adjusts the programmed dispensing to the passage of CO₂.
Vacuum pump: Permits conduit or tank vacuumisation. In this apparatus it works connected to a vacuum pump.
Vacuum tank: This is a small tank that functions as a vacuum reserve, and can be used whenever so required by the filling system.
Fluid lines: These are flexible pipes that allow the filling or drainage collector to be connected to the bottles.

The apparatus has other ancillary devices such as field analogue pressure gauges, relief valves, check valves, etc.
The control means comprise an interface for supervising the process and acting upon it, and a control system for executing the programs.
The interface includes a display screen that shows schematically the entire filling circuit, the devices that take part in the process and the various operations being carried out.
The control means also include a series of alarms that show process, instrument or system breakdowns. These alarms are explained below.
The control means also allow data to be displayed in real time and trends graphics to be created to present the process data being stored in the interface. They also permit examination of how the process is working at any given time.
The control system monitors and controls the entire apparatus. A system of control sequence modules carries out the filling process of the invention totally automatically.
There follows a description of the various control sequence modules needed to carry out the process of filling the bottles with CO₂. The schematic diagram of Figure 1 shows the parts to which reference is made.

a) Test sequence module:

This is the sequence that carries out a leaktightness test. It opens the filling valves 7, 8, 9 on each bottle 2, 3, 4 and CO₂ gas valves 10, 11; after a very short period of time, it closes the valves and saves in its memory the pressure in the bottles. It then allows a certain amount of time to pass and checks that there has been no excessive pressure loss and that a minimum pressure has been stored. The test is then taken as correct or otherwise and the sequence ends.

b) Filling process sequence module:

This is the sequence that controls the filling process. In its various steps calls are made to the subsequences that play a part in filling. At each step a subsequence start-up order is sent and the sequence executed beforehand, if there was one, is reset.
The first thing it does is order the turner to invert, which is a simple order requiring no subsequence. Once the turn has been inverted, it calls up the venting sequence. When the latter has finished, it calls up the washing sequence. Then it passes on to the vacuumising sequence. When vacuumising is completed it executes a simple order once again, that which causes the turner to return to its normal position, which is the filling position. When the turner is in the normal position the collector sequence is executed. Finally, the filling sequences of the three bottles are called up. Once the bottles are full the collector sequence is called up again.

b1) Venting sequence module:

Opens valves 12, 13, 14, 15 which permit emptying of the bottles 2, 3, 4, and, when the pressure of the regulator 16 has been reduced to below 0.3 bar (modifiable value) it closes valves 12, 13, 14, 15.
If this pressure cannot be achieved within the time allocated as alarm-generation time, a venting alarm is emitted.

b2) Washing sequence module:

This is the washing sequence for the selected bottles. It is executed if the number of washes exceeds zero.
In this sequence the bottles 2, 3, 4 are filled with CO₂ gas (after the first filling it will be mixed with the liquid CO₂ that remains in the collector) until a washing pressure is reached. If the alarm-generation time elapses without the right pressure being reached, a pressure alarm is emitted and valves 7, 8, 9 are closed.
If the pressure is reached, filling valves 7, 8, 9 close and emptying valves 12, 13, 14, 15 open to drain the contents of the bottles. As in the venting sequence, drainage is carried out until the pressure of the regulator 16 falls below 0.3 bar. If this is not achieved within the set time, the alarm is emitted.
If venting is carried out valves 12, 13, 14, 15 close and the washing finishes. If a washing sequence remains to be done (where the number of washes exceeds 1) the sequence is executed again. When no further washes are required, the sequence terminates.

b3) Vacuumising sequence module:

Creates a vacuum in the selected bottles 2, 3, 4, by opening valve 17 of the vacuum pump 18, and valves 12, 13, 14 for emptying the bottles 2, 3, 4. Once the necessary vacuum in each bottle has been achieved, the aforesaid valves are closed. An alarm is also assigned for this sequence if the vacuum is not achieved within the time set.
Finally, the filling collector of bottles 2, 3, 4 is drained by opening valves 19, 15. If pressure is not achieved in the regulator 16 the alarm will be emitted.

b4) Collector sequence module:

The purpose of this sequence is to avoid the problem of product queues between one filling and another.
It is executed twice in the course of the process. The purpose the first time is to fill the collector with product before starting the filling. For this purpose the liquid CO₂ inlet valves 10, 11 and the regulating valve 20 are opened until 50 bar is achieved. When this pressure has been reached, the regulating valve 20 and valve 11 close. The second time, the sequence closes only valves 10, 11.

b5) Filling sequence module for the first bottle 2:

If the first bottle 2 is not selected the sequence finishes immediately.
To fill the bottle 2 valves 10, 11 and regulating valve 20 open. The integrating module which acts as virtual weighing scales begins to increase. When 80% of the desired weight has been reached it activates the filling program. When 100% of the weight is reached, the filling program halts and regulating valve 20, valve 11 and the filling valves of bottle 2, in this case valve 7, close.
There are two possible alarms in this sequence: the first ensures that a certain time cannot be exceeded between opening of the valves and filling of the bottle. The second would be emitted if flow continued to pass once the regulating valve 20 and valve 11 had been closed.

b6) Filling sequence module for the second bottle 3:

The operation of this module is similar to the filling sequence module for the first bottle 2.

b7) Filling sequence module for the third bottle 4:

c) Drainage process sequence module:

This sequence is a final draining of the collector to avoid the line to each bottle having pressure when the bottles are released.
It opens emptying valves 12, 13, 14, 15 until a pressure lower than a set value is reached in the regulator 16. If that pressure is not reached, it activates a venting alarm.
After drainage it closes those valves and opens valve 19 in order to balance the pressures of the filling and emptying collectors, thereby preventing the pressure in the regulator 21 reaching its limiting value and causing an alarm to be emitted.
When this sequence finishes, the system goes into standby. To come out of this status the grips 5 must be deactivated, thereby indicating that bottles 2, 3, 4 have been changed.
The system alarms are classified into three types: process alarms, instrumentation alarms and system alarms.
Moreover, each alarm has three priorities assigned: low, medium and high. Each alarm has a different sound, which can be set up.
When an alarm arises in the system the alarm pilot light on the button panel comes on. If the alarm is of the type that halts the sequence, the pilot light will be a flashing light; if not, the pilot light will be a steady red light.
If the alarm halts the sequence, the system elements are set to a safe position and the display screen shows a small section with the reason for the alarm and a button. If this button is pressed the alarm sound stops, the alarm is acknowledged and the reason for the alarm is also removed. The process will remain halted until the continue command is pressed on the filling control screen. The system will start from the subsequence in which the process alarm arose, restarting that subsequence. Another option is to terminate the process using the pertinent control button.
The display screen can also show the process graphics for the status of the alarm, and its operating display section.
As noted above, the apparatus comprises a turner with three bottles. However, in order to improve filling times and therefore productivity the following two measures have to be implemented:

Increasing the capacity of turner 1: by increasing from three to four bottles, which allows unit times to be improved.
Fitting a second turner 1' (as shown in Figure 2): the second turner 1' allows the operative to devote much of his otherwise idle time to preparing the second turner 1' while the bottles on the first turner 1 are being filled. This permits an increase in the number of bottles filled per operative hour.

Independent of the subject-matter of this invention are the materials used to manufacture the parts making up the apparatus for carrying out the described process for filling bottles with gas, together with the shapes and dimensions thereof and all accessory details that might be presented, which can be replaced by others that are technically equivalent, as long as they do not affect its essential nature nor depart from the sphere defined by the claims attached below.

Claims

Process for filling bottles with gas, characterized in that it comprises the following stages:

a) Placing the bottles (2,3,4) on a swivelling support or turner (1).

b) Emptying the bottles (2,3,4) of their previous content by making the turner (1) swivel until the bottles (2,3,4) rest in an inverted position.

c) Making the turner (1) swivel again until the bottles are in the filling position.

d) Filling the bottles (2,3,4) with gas, whereby filling is controlled by means of a mass flow meter.
Process according to claim 1, characterised in that after stage b), a venting and washing or washing off operation of the bottles (2,3,4) is carried out.
Process according to claim 2, characterised in that after the washing or washing off, vacuum is applied and the collector is emptied.
Process according to claim 1, characterised in that the filling of the bottles (2,3,4) placed in a single turner (1) is carried out sequentially.
Process according to claim 1, characterised in that the washing can be repeated a plurality of times.
Apparatus for carrying out the process according to claims 1 to 5, characterised in that it comprises a turner (1) in which the bottles (2,3,4) are placed, an actuator that causes the turner (1) to swivel, a pneumatic circuit that connects said bottles (2,3,4) to a gas tank, pneumatic means (7 to 21) provided in said circuit for carrying out the operations of venting, washing, vacuumizing and filling, and control means that work upon the actuator and upon the pneumatic means (7 to 21) so as to permit an automatic control of said operations.
Apparatus according to claim 6, characterised in that the turner (1) comprises a swivelling structure, securing means (5) of the bottles (2,3,4) to said structure, means for activating said securing means (5) and lifting means (6) of the bottles (2,3,4).
Apparatus according to claim 7, characterised in that the securing means (5) of the bottles (2,3,4) are grips.
Apparatus according to claim 7, characterised in that the activation means are pneumatic pistons.
Apparatus according to claim 6, characterised in that the pneumatic means include a vacuum pump (18), a vacuum tank, a plurality of valves (7 to 15,17,19,20), a plurality of pressure transmitters (16,21) and at least one mass flow meter.
Apparatus according to claim 6, characterised in that the control means include an interface for supervising the process and intervening in it, and a control system for execution of the programs.
Apparatus according to claim 11, characterised in that the interface includes a display screen.
Apparatus according to claim 6, characterised in that the control means comprise a plurality of control sequence modules, such as a test sequence module, a venting sequence module, a washing sequence module, a vacuum sequence module, a collector sequence module, a filling sequence module for each bottle and a drainage sequence module.
Apparatus according to claims 11 to 13, characterised in that the control means include a series of alarms that indicate eventual process, instrumentation and system breakdowns.
Apparatus according to claim 14, characterised in that the alarms appear on the display screen.
Apparatus according to claims 11 to 15, characterised in that the control means permit the building of graphics for displaying data in real time.
Apparatus according to any one of the previous claims, characterised in that it includes a second turner (1').