Device for detecting damage to high-pressure processing bags

Abstract

Device for detecting the breakage of a high-pressure processing bag, wherein an elongate electrode (1) partially extends through the interior of one of the two stoppers (5a, 5b) at its proximal part and extends into the bag (6) containing the product to be processed at its distal part, and the electrode is electrically insulated along its entire length by an insulator (2) except for the part thereof within the bag (6) and the part thereof in contact with the product, wherein the proximal part of the electrode (1), i.e., the part protruding from the stopper, is connected to a power source and a device for measuring the current, resistance or capacitance of a circuit, and wherein if the bag ruptures, the device electrically connects by closing the circuit between the electrode and the pressurized water.

Description

Technical Field

[0001] The present invention belongs to the field of high-pressure processing devices and methods for multiple substances known as pumpable substances, particularly but not limited to fluids such as beverages, cosmetics, etc. Background Art

[0002] High-Pressure Processing (HPP) is a technology that, by applying pressures exceeding 4000 bar, seeks to reduce the microbial load without altering the characteristics of the processed product. The most popular high-pressure processing equipment operates by processing products previously placed in flexible packaging, such as bottles. The classic form of high-pressure processing is carried out batchwise, i.e., through a discrete and non-continuous process. Initially, the product inside the flexible final packaging is loaded into multiple containers (made of rigid plastic), which are introduced into a steel container, and then the steel container is filled with water. Once the container is filled, it is completely closed, and the water is pumped at high pressure through one or more high-pressure boosters until a pressure of 4000 - 6000 bar is reached. This pressure is maintained for a certain period of time, which can vary from a few seconds to several minutes depending on the so-called recipe.

[0003] A new method of processing liquids using high pressure is based on applying pressure to the liquid located inside a flexible bag or membrane within the processing container. The multiple steps of filling and emptying the bag are carried out without opening the machine, that is, without moving multiple wedges or multiple plugs. An example of this technology can be found in application PCT / ES2017 / 070600. The product to be processed is introduced and removed through a single product plug. This plug has an inlet pipe for the product and another inlet pipe for a cleaning agent. The product enters the flexible bag or membrane located inside the high-pressure chamber or container through a metal-to-metal seated valve. The air in the container is discharged by the vent plug having a similar valve but located at the top. Once the bag is filled, these valves are closed, and water is pumped into the container at high pressure through other pipes. The high-pressure water is introduced around the bag. The most common recipe is 6000 bar for three or four minutes (depending on the product to be processed), and during this period, the product pipe is cleaned.

[0004] During the processing, the bag or membrane may break. Referring to Figure 1 , the operating sequence of a bulk HPP device includes the following steps:

[0005] 1. Fill the pumpable substance into the bag 6 through the pipe 33' of the plug 5a.

[0006] 2. Pressurize the container: Pump water at high pressure through the plurality of pipes 20. The pressurized water is retained within the container 4 and outside the bag 6.

[0007] 3. Maintain the pressure within the container 4 for a predetermined period of time (selected by the operator when choosing the recipe).

[0008] 4. Decompress. Release the water within the chamber to the outside through a plurality of discharge valves located within the plurality of pipes 20, thereby releasing the pressure.

[0009] 5. Empty the bag. This step is carried out through the same filling valve on the plug 5a or another valve that can be enabled on any plug.

[0010] 6. These steps are repeated a certain number of times before changing the bag.

[0011] The integrity of the bag may be affected by multiple problems during the filling step of the bag, because if the number of liters introduced is not well controlled, the bag may burst due to the pump pressure. Multiple breakages may also occur during the step of decompressing the chamber. In this step, the pressurized water (which can reach 6000 bar) is instantaneously released from the chamber by opening the plurality of discharge valves. In order for the pressure to equalize with atmospheric pressure, the same amount of water introduced during the pumping step must flow out. Since the liquid tends to move from a region of higher pressure to a region of lower pressure, and considering that the water and the pumpable substance have the same pressure, when the valve is opened, both fluids tend to come out, such that the pumpable substance can drag the bag along the discharge path until it bursts when attempting to move towards the outside of the container. Another step in which the bag may suffer suction damage is during the emptying step, because it may be dragged towards the outlet path of the valve. Currently, the leak detection system for the bag is based on applying air pressure or any other gas to the outside of the bag once it has been emptied (step 5), so that if the bag bursts, the pressure can be detected in the product outlet pipe. However, sometimes due to creases on the bag or the pressure exerted on the container wall, the plurality of holes are sealed, and for this reason, this detection system is not reliable enough. In addition, since this method requires the bag to be completely emptied, if a breakage is detected, part of the emptied circuit needs to be cleaned, resulting in a loss of time because the product has already been emptied from the container. In the case where the bag is not broken, another drawback is that it takes a long time to completely empty the bag, because the last liter is emptied more slowly than the first liter, and since the entire product needs to be taken out to verify the integrity of the bag, the cycle time is extended. Summary of the Invention

[0012] The object of the present invention is to provide a device for detecting multiple ruptures of multiple bags of a high-pressure processing device, and the device solves the above-mentioned drawbacks. To achieve this, the present invention has a device equipped with means for measuring an electrical parameter (preferably resistance, capacitance or the current intensity) between the pressurized water around the bag and the product inside. Since the outside of the bag is in contact with the processing container and there is a small amount of water between the two, if there is a connection point between the inside and the outside of the bag and there is a rupture, the value of the electrical parameter measured between the pressurized water and the product will change. Therefore, by monitoring this parameter, it is possible to detect whether there is a rupture situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To help better understand the features of the present invention and supplement this description, a set of illustrative and non-limiting drawings has been attached as part of this specification:

[0014] Figure 1 Showing the steps of high-pressure processing of multiple pumpable substances in a device according to the state of the art.

[0015] Figure 2 Showing an outline of the present invention.

[0016] Figure 3 Showing multiple details of the present invention.

[0017] Figure 4 Showing another variation of the present invention, in which a connector connected to the pre-existing bag is used to introduce the electrode into the bag. DETAILED DESCRIPTION OF THE INVENTION

[0018] Referring to Figure 2 and Figure 3, in a high-pressure processing machine equipped with a container and two stoppers (5a and 5b) for closing the same container, the present invention includes an elongated electrode 1, which partially extends through the interior of the stopper 5a in its proximal portion and further extends in the distal portion until it is introduced into the bag containing the product to be processed. In the embodiment shown in the drawings, the electrode extends through the filling stopper 5a, but it can also be introduced into the container through other stoppers. In the proximal portion extending inside the stopper, a wire 13 connects it to a power supply, and the electrode serves as a cathode. In the portion passing through the stopper and its exterior, up to the region of the bag, the electrode is electrically insulated due to an insulator 2 (continuous coating or group of plastic parts). Thus, the electrode is insulated from both the stopper and the pressurized water 10. In the middle, the electrode may have a thickening to ensure mechanical contact with the stopper. To hold the position of the electrode and ensure the mechanical contact, a lid 7 is placed on the electrode, which pushes the electrode to create a seal between the male conical shape of the electrode and the female conical shape of the stopper. The bag 6 containing the product to be processed preferably but not necessarily has a connector 9 connected to the bag, and the electrode is introduced through the connector 9 ( Figure 3 ). Alternatively, the electrode can be introduced into the filling stopper from the bag through the same pre-existing connector 14 ( Figure 4 ), because an auxiliary connector 9' is connected to the connector 14 of the bag, preferably but not necessarily through a central connector 15, to facilitate its assembly. In the last part of the electrode inside the bag, it does not have insulating material because it contacts the product to be processed.

[0019] In the first embodiment, in the case where the connector 9 of the electrode is separated from the connector 14 of the bag, the connector 9 and lid 7 assembly optionally provides a flange 12. The flange 12 fixes everything together to ensure the seal of the assembly during all steps of the processing, preventing the alternating current between the pressurized water 10 and the product to be processed in the bag that would cause contamination of the product.

[0020] In Figure 4 the second embodiment shown, the connector 14 of the bag 6 connected to the product stopper 5a has an auxiliary connector 9', preferably but not necessarily with the central connector 15, for introducing the distal portion of the electrode, where the electrode is not coated as described above.

[0021] The bag 6, the connectors 9, 9' and 14, and the central connector 15 must be made of electrically insulating materials.

[0022] The power supply to which the wire 13 and the electrode 1 are connected (optionally only the electrode if it is made long enough) is direct current between 6 and 60 volts (Volts), preferably about 24 volts. The smaller the voltage, the less precise the system, but the larger the voltage, when the potential difference is applied to the electrode, electrolysis will occur in the product to be processed. The cross-section of the electrode should be greater than 1 square millimeter (mm 2 ). The larger the cross-section of the electrode, the more precise the system.

[0023] The anode is a second electrode 13', which is in hydrostatic contact with the pressurized water. In the most common case, the high-pressure machine is made of metal, and in this case, it is only necessary to simply connect an electrode to an outer part of the processing container, or even to the plug 5a in contact with the pressurized water.

[0024] In the case where the high-pressure processing machine is of the type described in application PCT / ES2017 / 070600, the device has a single product filling and emptying pipe and a single valve, the male and female seats of which are made of metal. Thus, in the male seat 8 of the valve, a plastic film 3 is provided in the distal region, the distal region being closest to the bag 6; the film is connected by a rod made of an insulating material to ensure no electrical contact. However, the female connector of the bag 14 is made of plastic and is thus an electrical insulator. Thus, when the male seat 8 is closed, its movement causes the film 3 to move, since it is integral with the male seat 8 and it becomes electrically insulated from the bag 6 of the male seat 8 and thus from the pressurized water 10. Since during pressurization the volume of the pumpable substance between the film 3 and the filling / emptying valve 8 decreases, it is necessary to have a system for the pumpable substance to pass through the interior of the bag 6 to balance the pressure on both sides of the film 3 and prevent the components 11 or 14, or even the film 3 itself, from collapsing. This function is accomplished by a one-way valve 5, which can be a plastic ball with a spring return or a membrane. The one-way valve 5 must always be made of an electrically insulating material. The combination of the membrane and the one-way valve can prevent the generation of an electric current through the filling valve and keep the circuit open. Just as the electrode needs to be insulated, the filling valve must also be insulated by the membrane and the one-way valve.

[0025] The electrical parameters can be monitored throughout the pressurization cycle, although it is usually monitored after the pressurization cycle is completed, with the product during the pressurization process being brought to atmospheric pressure before the bag is emptied. To this end, a voltage is applied to the electrode 1. If the bag is about to break, since both the container and the plug are made of metal (electrical conductor), a current will pass through the circuit, from the inside of the bag to its outside, and through the pressurized water to the container / plug until the circuit is closed, generating a current whose intensity can be measured. If the bag maintains its integrity, the circuit remains open because it is made of insulating material, so even if a voltage is applied to the electrode on the plug, no current will pass through the same movement because the circuit is not closed. In the same way, instead of its intensity, the capacitance or resistance of the circuit can be measured.

[0026] The device of the present invention is capable of detecting multiple small defects in the integrity when the processing bag is full, making it possible to avoid contamination of the cans and the product line being processed in the event of a positive detection. The method is fast and does not affect the cycle time as in the current state of the art. It also prevents false positives or false negatives. Finally, it is compatible with multiple existing systems, supports high-pressure limits, and is easy for production operators to handle and install when replacing the bag.

[0027] Based on this specification and the drawings, experts in the field can understand that the present invention has been described according to some of its preferred embodiments, but various changes can be introduced in such preferred embodiments without departing from the objectives required by the present invention.

Claims

1. A high-pressure processing machine, the high-pressure processing machine having a bag (6), a processing container, and at least one filling plug for closing the processing container, characterized in that: The high-pressure processing machine has means for detecting breakage of the bag (6), said means being equipped with an elongate electrode (1) which, at its proximal part, is adapted to extend partly through the interior of the at least one filling plug and, at its distal part, is adapted to extend into the bag (6) containing the product to be processed, the electrode being electrically insulated along its entire length by an insulator (2) except for its part within the bag (6) and its part in contact with the product, wherein the proximal part of the electrode (1) which is intended to project out of the filling plug is connected to a power source and a measuring means for measuring the current, resistance or capacitance of a circuit, and wherein the measuring means is electrically connected to the circuit closing between the electrode and the pressurized water in the processing vessel.

2. The high-pressure processing machine according to claim 1, wherein: The electrode (1) extends through the filling plug.

3. The high-pressure processing machine according to claim 1 or claim 2, characterized in that: The electrode (1) has a thickened part and a cap (7) to facilitate sealing of the electrode to the filling plug.

4. The high-pressure processing machine according to claim 3, wherein: The electrode (1) extends into the bag (6) through a connector (9).

5. The high-pressure processing machine according to claim 4, characterized in that: The cap (7) and the connector (9) are connected by a flange (12).

6. The high-pressure processing machine according to claim 1, characterized in that: The electrode (1) extends into the bag (6) together with the filling plug through another connector (14) of the bag (6).

7. The high-pressure processing machine according to claim 6, characterized in that: The electrode (1) extends into the bag (6) through the another connector (14) by means of an auxiliary connector (9') located on the another connector (14) itself or on a central connection piece (15).

8. The high-pressure processing machine according to claim 7, having a single said filling plug and a valve for filling and emptying the product, characterized in that: The valve is equipped on its male seat (8) with a plastic film (3) and a non-return valve (5) made of insulating material.

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