Patent Description:
High pressure processing (HPP) is a technology that uses pressures greater than <NUM>,<NUM> bar to reduce the microbial load of a product without altering the characteristics thereof.

HPP equipment known for treating liquids or other substances with high pressure are based on the processing of the product previously arranged in flexible packaging, for example bottles. The classic way of high pressure processing is performed in batches of packaged products, in other words, by means of a discreet and non-continuous process. Initially, the products inside the flexible final packaging thereof are loaded into containers (made of rigid plastic) that are inserted into a steel vessel that is subsequently filled with a pressurisation fluid, generally water, leaving unoccupied gaps between the packaging. Once the vessel is full, it is completely closed and water starts to be pumped at high pressure through one or several high pressure intensifiers until reaching <NUM>,<NUM>-<NUM>,<NUM> bar. Said pressure is maintained for a time that can vary from seconds to several minutes. The pressure reached and the time that this pressure is maintained are the main parameters of the process and they are defined in each case based on the product that is going to be processed (which is commonly called the "recipe"). For example, in the case of a beverage, the technology is used for the effect of inactivating microorganisms therein and the recipe is defined based on the level of microorganism inactivation that is to be reached. Finally, the pressure is released, the containers are taken out of the inside of the vessel and the processed product is removed. The product has been sanitised, meaning that the microbial load has been reduced.

In an HPP process the pressure is transmitted to the product through the pressurisation fluid, hence the pressure is transmitted equally and instantaneously to all the points of the product. Given that the product is processed while already packaged, the filling coefficient of the vessels (relationship between the product volume to be processed and the useful volume of the vessel) is low, between <NUM>% and <NUM>%, depending on the geometry of the packaging and the diameter of the vessel. The main advantage of processing in batches is the absence of subsequent contamination of the product, since from the beginning it is in the final packaging thereof. On the other hand, the main disadvantage is that the low filling coefficient reached limits the productivity of traditional high pressure processing equipment. Other disadvantages of batch processing are the need to use flexible packaging that supports the effects of the high pressures, it not being possible to use materials such as glass, and the need to handle them for the loading and unloading of the HPP machine.

Therefore, the need arises to search for an alternative to the current way of processing that successfully increases the filling coefficient of the vessel and avoids the restrictions of this type of packaging, ensuring that after the processing of the product no contamination is produced, this last one being the most complicated to accomplish.

Over time, different solutions have been proposed, one of these consisting of processing liquids inside a bag or flexible membrane situated inside the vessel and which occupies the largest useful space possible.

To make a distinction with HPP processing of already packaged products, the process with a bag or membrane is called bulk HPP. For the sake of simplicity, hereinafter we will call the bag or membrane simply a bag.

Examples of bulk HPP systems are the ones described in <CIT> <CIT>, <CIT> or <CIT>, where different systems for bulk HPP of pumpable substances are shown.

One of the challenges of bulk HPP equipment is ensuring that the pressurisation fluid (generally water) and the pumpable substance are not able to mix. To do so, two things must be ensured: that the connection of the bag is completely sealed and that it does not get broken.

In reference to <FIG>, the sequence of operations of bulk HPP equipment consists of the following steps:.

The filling step can present problems for the integrity of the bag, since if the amount of litres introduced is not controlled well it is possible to break the bag with the pumping pressure itself. However, breakage can also occur in the chamber depressurisation step. During this step the pressurised water, which can be at <NUM>,<NUM> bar, is released by instantaneously opening the unloading valves 6a and 6b. In order for the pressure to be the same as the atmospheric pressure, it is necessary for the amount of water that leaves to be the same as the amount introduced in the pumping step. Given that liquids tend to move from areas with higher pressure to areas with lower pressure and given that both the water and the pumpable substance are at the same pressure, both fluids tend to move to the outside when valves 6a and 6b are opened, such that the pumpable substance, in the intent thereof to move towards the outside of the vessel, drags the bag along the unloading path until it breaks.

Furthermore, it is possible for the pressurisation water to not be distributed homogeneously on both sides of the vessel due to multiple reasons, such as having more pumps connected on one side than the other, or that, during unloading, the valves do not open at exactly the same time which makes more water come out on one of the sides.

The problem of this asymmetric distribution of the water in the vessel is that, when the depressurisation occurs, given that on one side there is less fluid, the bag will tend to be dragged by the unloading duct on that side. Furthermore, it is possible that small pools of water form in points of the central area of the vessel <NUM>, the contents of which do not find an outlet path towards the unloading valves during the depressurisation step. As mentioned above, if all the pressurisation water does not leave the vessel, that which will tend to leave will be the pumpable substance, breaking the bag.

Another step where the bag can be damaged by suction is in the emptying step, since it can be dragged towards the outlet path of the valve <NUM>. Apart from breakage, this phenomenon can give rise to said unloading path for the product to become blocked, in this way making the emptying of the bag impossible.

The present invention is as defined in the claims. The object of the present invention is that of providing a system and a method that prevents differences in the distribution of the pressurisation fluid inside the vessel, the possible formation of pools of water far from the unloading areas and excess pressures generated during the filling and emptying steps of the vessel at high pressure of an HPP equipment from being a problem for the integrity of the bag or hindering the unloading of the product.

To do so, the system of the present invention provides a bag protection and securing system for bulk high pressure processing equipment provided with at least one tube with holes, covers for evacuating and connecting the ends of the tube or tubes, the tubes being, in the case that there are two or more, anchored to said covers in positions that are optionally symmetrical with respect to the central shaft of the covers; protection means for the bag adapted to lengthen and thus facilitate the outlet path of the processed product once the depressurisation of the equipment is produced and a fitting for the protection means from the bag to the cover on the side from which the product in the bag leaves. Advantageously, the holes of the tube or tubes are oriented towards the inner face of the vessel. The protection means have a spiral, mesh, strap or cylinder shape with holes and they preferably extend inside the bag to at least ¾ of the length thereof. The tube or tubes have a circular, oval or square cross section. The holes of the tube or tubes preferably have a diameter between <NUM> and <NUM>. The covers for evacuation and connection are optionally provided with conduits for the outlet of the pressurisation fluid and the tube or tubes are provided with a telescopic section.

The invention further comprises high pressure processing equipment comprising the system of the invention and a method for the use thereof.

In order to assist in a better understanding of the characteristics of the invention and to complement this description, the following figures, of illustrative and non-limiting nature, are attached:.

In reference to <FIG> and <FIG>, the system for protecting and securing the bag is made up of perforated tubes <NUM> that extend along the inside of the vessel <NUM> (although <NUM> are shown in the figures, there could be from a single tube up to twenty) and covers for evacuating and connecting the ends of the tube or tubes 11a and 11b. It is further provided with means for protecting the bag <NUM> that aim to facilitate the outlet path of the processed product. By facilitating the outlet path of the treated product, the pressure on the bag is diminished. They are therefore any lengthened means having an increased surface along which the treated product is distributed and they have a spiral, mesh, strap or cylinder shape with holes. The protection means extend inside the bag and preferably have at least ¾ of the length thereof. The means <NUM> are secured to the fitting <NUM> of the plug 3a through a support <NUM>. The product can pass through the fitting <NUM>. The means <NUM> are preferably manufactured from stainless steel, which gives them the sufficient rigidity to not collapse during the emptying of product due to the pressure on the outside of the bag and makes them resistant to corrosion that the different products can produce. The support <NUM> is provided with holes. The means <NUM> and the support <NUM> protect the integrity of the bag during the emptying of the product and prevent the bag from being sucked through the outlet circuit, since they lengthen the outlet path for the product and make the suction not focus rapidly on one point with a narrow diameter at the outlet of the bag but rather on an increased surface. In this manner, the bag, if collapsed, does so on the protection means and not on a small area.

The covers 11a and 11b for evacuating and connecting the ends of the tube or tubes are manufactured from stainless steel in order to support on one side the stresses created during the high-pressure unloading and to be resistant to the corrosion produced by the pressurisation fluid. They guarantee continuity in the outlet path of said fluid and eliminate the risk of suction of the bag at any point. Through the covers, which are provided with channels <NUM>, the unloading path 8a, 8b is connected to the tube or tubes <NUM>. The connection of the tube or tubes <NUM> to the covers for evacuating and connecting 11a and 11b is made through mechanical means, preferably with quick connection to facilitate the operation. Each one of the tubes <NUM> is manually inserted into the housings of the anchoring points <NUM> (<FIG>) in both covers and they are locked mechanically.

The cover 11a through which the product enters is provided with a housing for the fitting <NUM>. The opposite cover 11b is provided with the channels <NUM> but not with the housing for the fitting in the case in which the product enters and leaves through the same valve. Otherwise, (see <FIG>) the cover 11b will be provided with a fitting for the product inlet.

The protection and securing system in the assembly thereof provides the following advantages:.

The perforated tube or tubes <NUM> have a section preferably without edges that can mark the bag and damage it when it is full. They can have a circular, square, elliptical or other shape. The number of tubes is variable, preferably three and the dimensions thereof are, preferably but not necessarily, between <NUM> and <NUM> in diameter. The length of this tube or tubes corresponds to the distance between plugs of the machine. In at least one of the ends of the tube a telescopic section is foreseen which enables the connection thereof to the covers when these are outside the vessel, in the bag assembly phase, since the distance between covers will be reduced in the step before the subsequent pressurisation. The tube or tubes have outlet/inlet holes 10a. The diameter thereof is preferably between <NUM> and <NUM>. The holes can also have a slot shape or have different diameters. They are arranged along the entire length of the tube, oriented towards the inner face of the vessel <NUM> such that the bag <NUM>, located in the inner space defined by the tubes <NUM>, in the case of there being more than one, cannot reach these holes during the high pressure unloading phase, thus preventing the possible suction of the bag <NUM> and the consequent breakage thereof.

Possible materials for the tube or tubes are <NUM> stainless steel or plastic, in order to minimise the risks of metal-metal contact with the vessel and the consequent damage to it. On both ends of the tube or tubes <NUM>, sliding and fastening bushings <NUM> are arranged in order to enable and limit the movement of the telescopic tubes and prevent contact of the tube or tubes <NUM> with the vessel <NUM>. Furthermore, the bushings have the function of an anchoring point for the bag in order to keep it in the correct position throughout all the cycles in which it will be used, as will be seen further on. The bushings can be manufactured from plastic material, preferably high-density PE. Furthermore, tube spacers <NUM> made of preferably plastic material are arranged, the main function of which is to keep the tubes <NUM> joined and conveniently orient them with the holes towards the vessel. They also prevent the contact of said tubes with the vessel <NUM> and further act as support points for the treatment bag during the insertion and extraction phases of the processing vessel. In the case of there only being one tube, the spacers <NUM> would continue to orient it with the holes towards the vessel and would also prevent the contact of the tube with the vessel, as well as continuing to act as support points for the treatment bag. The joint of the spacers <NUM> and the tube or tubes <NUM> is preferably made with non-metal fittings.

The process of bulk HPP treatment by means of equipment incorporating the system of the invention is as follows:.

The bag is joined to the bushings <NUM> by means of elastic bands in order to maintain the fixed position thereof in successive cycles that will be performed with it and prevent possible movements or twisting that can be produced due to the effects during the phases of the process such as the high pressure unloading.

Claim 1:
A system for protecting and securing bags in a bulk high pressure
processing equipment having a vessel, characterised in that it comprises:
- at least one tube (<NUM>) provided with holes (10a);
- covers (11a and 11b) for evacuating pressurisation fluid and connecting the ends of the tube or tubes (<NUM>), the tube or tubes being anchored to said covers;
- protection means for the bag (<NUM>) configured to extend inside the bag to lengthen the outlet path of the processed product once the depressurisation of the equipment is produced, said protection means (<NUM>) having a spiral, mesh, strap or cylinder shape with holes;
- a fitting (<NUM>) for the protection means (<NUM>) for connecting the protection means to the cover (11a) on the side from which the product in the bag comes out.