FR2902342A1 - METHOD, DEVICE AND INSTALLATION FOR DECONTAMINATION OF A CALORITIVE FLUID - Google Patents

Abstract

The invention relates to a method for the decontamination of a heat transfer fluid, in particular water, circulating in a cooling circuit (6) and in a cooling tower (5) that comprises an installation (1) for the cooling of at least one machine (4) or the like.This process is characterized in that the decontamination consists in ensuring at least one aseptic filtration of the circulating heat transfer fluid.The invention also relates to a device (9) for decontaminating such heat transfer fluid, this device (9) being designed in particular to implement the aforementioned method.Finally, the invention relates to a cooling installation (1) of at least one machine (4) and comprising such a device (9) of decontamination.

Description

The present invention relates to a method for decontaminating a fluid of

  cooling circulating in a cooling circuit and in a cooling tower that includes an installation for cooling at least one machine or the like. This invention also relates to a device for ensuring such decontamination and to a cooling installation comprising such a device. This invention relates to the field of decontamination of circulating fluids in installations designed to cool at least one machine or the like and will find a particularly suitable application in the context of a cooling installation comprising a cooling tower. In known manner, such installations comprise a reservoir containing a fluid, usually water, for supplying a cooling circuit. This cooling circuit is connected to at least one machine or the like in order to supply cold fluid for cooling the machine. The fluid heated by this machine is removed from it and circulates in the cooling circuit to be routed to a cooling tower for cooling. The fluid cooled by the cooling tower is then conveyed by the cooling circuit to the reservoir for a new cooling cycle. It will be observed that the reservoir is supplied with fluid, more particularly with water, which is usually city water containing undesirable compounds and organisms, more particularly microorganisms, bacteria, especially legionella bacteria responsible for legionellosis. This water circulates in the cooling circuit and reaches, on leaving the machine to cool, an ideal temperature for the proliferation of bacteria such as Legionella. This water then enters the cooling tower in which it is vaporized as a plume of water vapor, containing legionella in suspension, and can be inhaled by people who can then contract Legionella . A solution has been developed to overcome such a disadvantage and consists in pouring into the water of the reservoir, a chemical at least partly consisting of a bactericide. This chemical then circulates in the cooling circuit and limits, at least temporarily, legionella emissions.

  However, this solution has many disadvantages. Indeed, this chemical is particularly expensive. In addition, the microorganisms and bacteria present in the water of the cooling circuit have an important adaptability and quickly develop resistance to the chemical and, in particular, the bactericide. This being so, it is regularly necessary to increase the dose of this chemical and / or to change the composition of this product which considerably increases the cost of water treatment. Another disadvantage is that the chemical contained in this water is also vaporized by the cooling tower so that its constituents are also likely to be inhaled which represents a significant health risk. Finally, the maintenance of a cooling installation consists in regularly draining the reservoir containing the water in which the chemical is diluted and, therefore, the bactericide. In the absence of an appropriate pollution control system, the emptying is done, usually, in the public sewage system, to see and in the worst case, directly in the nature. This chemical is then likely to cause significant pollution of the environment.

  The present invention is intended to overcome the disadvantages of installations of the state of the art.

  To this end, the invention relates to a method for the decontamination of a heat transfer fluid, in particular water, circulating in a cooling circuit and in a cooling tower that includes an installation for cooling at least one machine or analogous, characterized in that the decontamination consists in ensuring at least one aseptic filtration of circulating heat transfer fluid. According to another characteristic, this decontamination process also consists in providing a sterilizing filtration, or even a sedimentary and / or absorbing filtration of circulating heat transfer fluid. In fact, it ensures the filtration of the heat transfer fluid upstream of the cooling tower.

  More particularly, the decontamination is carried out by filtering the heat transfer fluid contained in a supply tank of the cooling circuit and that includes the cooling installation. The invention also relates to a device for decontaminating a heat transfer fluid circulating in a cooling circuit and in a cooling tower that includes an installation for cooling at least one machine or the like, this device being in particular designed to implement the aforementioned method. This decontamination device is characterized in that it comprises at least one means for ensuring aseptic filtration circulating heat transfer fluid. Another feature is that it further comprises means for providing sterilizing filtration, or even a means for providing sediment filtration and / or means for providing absorbent filtration of circulating heat transfer fluid. In fact, the filtration means are arranged, in series, within at least one set, or even a plurality of parallel games, of filtration means.

  An additional feature is that the device comprises, on the one hand, means for supplying the filtration means or means for heat transfer fluid to be decontaminated and, on the other hand, means for supplying the fluid installation with The invention finally relates to an installation for cooling at least one machine or the like and comprising a cooling tower, a cooling circuit, a supply tank for this circuit as well as a cooling circuit. a heat transfer fluid, especially water, circulating in this installation. This installation is characterized in that it comprises a device, having the aforementioned characteristics, and designed to decontaminate the heat transfer fluid. Unlike the state of the art which consists in ensuring a chemical treatment of the fluid flowing in the cooling circuit, the present invention consists in applying to this fluid a physical treatment by filtering it.

  Advantageously, such a filtration makes it possible to avoid the storage and manipulation, by an operator, of expensive and dangerous chemicals. In addition, the filters making it possible to ensure such filtration are advantageously designed so as to be able to harvest the residues of this filtration with a view to their elimination or recovery, this in a waste treatment circuit that is perfectly controlled and respectful of the environment. Yet another advantage is that the filtering means, especially in the form of cartridges, are interchangeable type and can be easily and quickly replaced, in particular without interrupting the circulation of cooling fluid in the installation. In addition and advantageously, these filtering means can be of conventional design or even be commercially available.

  According to another advantage, the decontamination device is likely to come to equip an already existing cooling installation, or even an installation whose decontamination was provided in advance by chemical treatment. Surprisingly, the filtration method according to the invention has an increased efficiency compared to such a chemical treatment and a cost and maintenance cost less.

  Other objects and advantages of the present invention will become apparent from the following description relating to embodiments which are given by way of indicative and non-limiting examples. The understanding of this description will be facilitated by referring to the appended drawings in which: FIG. 1 is a schematic view of a cooling installation according to the invention; FIG. 2 is a diagrammatic and detailed view of a decontamination device that comprises the installation of FIG. 1; FIG. 3 is a view similar to the previous one and corresponds to a second embodiment of such a decontamination device; FIG. 4 is a diagrammatic and detailed view of a filtration means included in the decontamination device according to the invention. The present invention relates to the field of decontaminating circulating heat transfer fluids in facilities designed to cool at least one machine or the like. As can be seen in FIG. 1, such a cooling installation 1 comprises a reservoir 2 containing a heat-transfer fluid, in particular water, intended to ensure such cooling. This tank 2 can be supplied with heat transfer fluid by appropriate supply means, in particular constituted by a supply line of city water. This installation 1 comprises, again, at least one means 3 for its connection to at least one machine 4 which should be provided with cooling with the heat transfer fluid. In this regard, it will be observed that such a machine 4 may be constituted by an air conditioning unit, a production unit, a production line or other. It is, more particularly, at the level of such a machine 4 that a heat exchange occurs between this machine 4 and the heat-exchange fluid that heats up. As can be seen in FIG. 1, said installation 1 furthermore comprises a cooling tower 5 designed to ensure cooling of the heat-exchange fluid heated by the machine (s) 4. Such a cooling tower 5 ensures, in a manner known per se, a exchange of heat between the air and the heat transfer fluid, this to cause a vaporization of a portion of this fluid. This installation 1 furthermore comprises a cooling circuit 6 inside which circulates the heat transfer fluid and constituted, on the one hand, by a first pipe element 8 designed to connect the tank 2 to the machine (or machines). (s) 4 to cool, on the other hand, by a second pipe element 8A designed to connect this or these machines 4 to the cooling tower 5 and, secondly, by a third pipe element 8B designed to connect this air-cooling tower 5 to said tank 2. Finally and as can be seen in FIG. 1, this cooling installation 1 comprises means 7 designed to circulate this heat-transfer fluid in this circuit 6. Such a means 7 is usually constituted by by a pump or the like making it possible to give the fluid a flow rate of between 50 and 350 m 3 per hour, in particular of the order of 100 m 3 per hour.

  According to the invention, this installation 1 comprises a device 9 designed to ensure the decontamination of the heat transfer fluid circulating in said cooling circuit 6 as well as in the cooling tower 5 that includes this installation 1. In fact, this decontamination device 9 comprises at At least one means 10 for providing aseptic filtration of circulating heat transfer fluid. Such a means 10 of aseptic filtration is designed to provide a bactericidal function, more particularly by inhibiting any type of bacteria, including Legionella. This aseptic filtration means 10 has a filtration threshold of 1 μm nominal. A preferred embodiment is that this asepticizing filtration means comprises at least one silver polypropylene element with a silver content of between 1 and 5%, preferably of the order of 2%. According to another characteristic of the invention, the decontamination device 9 comprises, again, a means 11 for sterilizing filtration of the heat transfer fluid. This sterilizing filtration means 11 is designed to ensure the retention of any element whose size is greater than 0.25 μm or even (and preferably) greater than 0.2 μm. To do this, said sterilizing filtration means 11 then has a retention threshold of at least 0.25 μm, or even 25 (and preferably) of the order of 0.2 μm. In this connection, it will be observed that, on the one hand, the smallest bacterium known to date measures 0.28 μm and, on the other hand, this sterilizing filtration means 11 is, more particularly, designed to ensure retention of all the bacteria, especially those which have been inhibited by the aseptic filtering means, especially legionellae. A preferred embodiment is that this sterilizing filtration means 11 comprises a membrane made of polypropylene, more particularly heat-blown polypropylene. In fact and according to a particular embodiment of the invention, such a membrane consists of 3 sheets of polypropylene. An additional feature is that this decontamination device 9 further includes means 12 for providing sedimentary filtration of circulating heat transfer fluid. This means 12 sedimentary filtration is designed to ensure the retention of all impurities suspended in the heat transfer fluid whose size is greater than 5pm.

  To do this, such a means 12 sedimentary filtration has a retention threshold nominal 5pm. In fact, this sediment filtration means 12 makes it possible to eliminate the impurities in the heat-transfer fluid and, consequently, to reduce the nutritive substances serving as a nutrient for the bacteria or other microorganisms. A preferred embodiment of the invention consists in that this means 12 of sedimentary filtration comprises a membrane made of polypropylene, in particular heat-blown polypropylene.

  Yet another feature is that the decontamination device 9 comprises a means 13 for absorbing filtration of the heat transfer fluid. This means 13 of absorbent filtration is designed to remove the bad taste and / or unpleasant odors of the heat transfer fluid. For this purpose, this means 13 of absorbent filtration essentially ensures a dechlorination of the heat transfer fluid by absorbing, more particularly, organochlorine compounds. According to a preferred embodiment of the invention, this absorbent filtration means 13 comprises an element made of activated carbon, more particularly based on coconut charcoal, compacted and extruded. It will again be observed that this means 13 of absorbent filtration has a nominal filtration threshold of 5pm.

  According to another characteristic of the invention and as shown in FIG 4, at least one of these means (10; 11; 12; 13) of filtration (and preferably all of these filtration means 10, 11, 12 , 13) is in the form of a filter cartridge 14 having a housing 15 provided, on the one hand, with a connection means 16 to a conduit for supplying the cartridge 14 with fluid to be filtered and, d on the other hand, a connection means 17 to a conduit for discharging the filtered fluid into this cartridge 14. The casing 15 of this cartridge 14 contains, internally, at least one element 18 (in particular a membrane or other) designed for ensure a specific filtration and of the type mentioned above (aseptic, sterilizing, sedimentary or absorbing). As can be seen in FIGS. 2 and 3, the filtration means (10; 11; 12; 13) are preferably arranged in series within at least one set 19 of cartridges 14.

  A particular embodiment of the invention illustrated in FIG. 3 concerns a decontamination device 9 comprising a plurality of sets 19, 19A, 19B of cartridges 14, these sets 19, 19A, 19B being arranged in parallel within said device 9.

  In this regard, it will be observed that such an embodiment is, more particularly, suitable for a cooling installation 1 and / or a decontamination device 9 in which (of) the heat transfer fluid circulates at high speed.

  In this regard, it should be noted that, in a set 19 of cartridges 14, these filtering means (10; 11; 12; 13) are then arranged in a preferred order and that the heat transfer fluid enters firstly, in the sediment filtration means 12, to then penetrate into the absorbent filtration means 13 in order to subsequently penetrate into the aseptic filtration means 10 and finally to penetrate the sterilizing filtration means 11, before leaving the device 9 decontamination. As can be seen in FIGS. 2 to 4 corresponding to preferred embodiments of the invention, the filtering means (10; 11; 12; 13) can be connected to each other (indirectly or, and preferably, directly) by via connection means (16, 17) of the reversible type, in particular of the type "union". Such reversible connection means advantageously allow easy dismantling of such a filtering means (10; 11; 12; 13), particularly with a view to its replacement and / or its maintenance (in particular its cleaning). According to another characteristic of the invention, the decontamination device 9 comprises, on the one hand, a supply means 20 for the filtration means or means (10; 11; 12; 13) for heat transfer fluid to be decontaminated and, d on the other hand, a supply means 21 for the installation 1 of heat-transfer fluid decontaminated by this or these filtration means (10; 11; 12; 13).

  In this respect, it should be noted that, according to a first embodiment of the invention (not shown), said decontamination device 9 is implanted between the machine (s) 4 to be cooled and the air-cooling tower 5. In such an embodiment, the decontamination device 9 is, in fact, implanted within the cooling circuit 6, more particularly within the aforementioned pipe element 8A. In this case, the supply means 20 is constituted by means of connection to one or more machines 4 while the supply means 21 is constituted by means of connection to the cooling tower 5 designed to supply the latter 5 with decontaminated heat transfer fluid. It will be observed that such an embodiment is perfectly conceivable but could have a number of disadvantages. Among these drawbacks, it will be observed that the flow rate of heat transfer fluid is high (between 50 and 350 m 3 per hour), which therefore necessitates sizing of the decontamination device 9 (in particular by multiplying the sets 19 of 35 cartridges 14) and / or to use filtration means (10; 11; 12; 13) particularly powerful, which considerably increases the cost of the decontamination device 9 and that of the cooling installation 1. In addition, the implantation of such a device 9 for decontamination within the cooling circuit 6 can cause problems in case of intervention (maintenance, repair) on this device 9 which can result in a complete shutdown of the cooling installation 1 and consequently, machines 4 to be cooled, which is difficult to accept, especially in the case of production machines.

  Also, and in order to overcome these drawbacks, the invention consists, according to a second embodiment illustrated in FIG. 1, of implanting the decontamination device 9 at the level of the heat transfer fluid reservoir 2 so as to ensure the decontamination of the heat transfer fluid contained therein. in this tank 2, this before this fluid is put (or put back) in circulation in the cooling circuit 6. In such a case, the supply means 20 is constituted, on the one hand, by a conduit 22 immersed in the fluid contained in the reservoir 2 and designed to take caloriporteur fluid to be decontaminated, and, on the other hand, a pump 23 for suctioning and conveying heat transfer fluid to be decontaminated to the filtration means or means (10; 11; 12; 13). Regarding the feed means 21, that is designed to re-feed the tank 2 of heat transfer fluid from the same tank 2 and decontaminated by the filter means (10; 11; 12; 13). In fact, such a supply means 21 may, again, be constituted by a conduit 24 adapted to discharge the decontaminated heat transfer fluid into the reservoir 2. As can be seen in FIGS. 2 and 3, the decontamination device 9 according to FIG. the present invention may be in the form of an autonomous device, individualized and independent of the cooling installation 1. In this respect, such a decontamination device 9 can be implanted at the level of the tank 2 of an existing cooling installation 1, in particular of the type previously treated in a chemical manner, for example using a bactericidal agent. However, according to another embodiment, such a decontamination device 9 may be an integral part of such a cooling installation 1. The invention thus also relates to a cooling installation 1 comprising a decontamination device 9 having the above-mentioned characteristics. The invention also relates to a method for the decontamination of a heat-transfer fluid (in particular water) flowing in the cooling circuit 6 and in the air-cooling tower 5 that comprises such an installation 1 for cooling at least a machine 4 or the like. According to the process according to this invention, the decontamination consists in ensuring at least one aseptic filtration of circulating heat transfer fluid, by means of the above-mentioned aseptic filtration means. However, according to a preferred embodiment of the invention, this decontamination also consists in providing a sterilizing filtration (by means of the above-mentioned sterilizing filtration means 11), or even a sedimentary filtration (via the means 12 of aforementioned sedimentary filtration) and / or absorbent filtration (through the abovementioned absorbent filtration means 13) of circulating heat transfer fluid. In fact, such a filtration of the heat transfer fluid is provided upstream of the air-cooling tower 5. According to a particular embodiment, such filtration is provided between the machine (s) 4 to be cooled with the aid of this However, and according to a preferred embodiment of the invention, this method consists in ensuring the decontamination by filtering the heat transfer fluid contained in the supply tank 2 of the cooling circuit 6.

  Although the invention has been described with respect to a particular embodiment, it is understood that it is in no way limited and that various modifications of shapes, materials and combinations thereof can be made. various elements without departing from the scope and spirit of the invention.

Claims (11)

  1) A method for the decontamination of a heat transfer fluid, in particular water, circulating in a cooling circuit (6) and in a cooling tower (5) that comprises an installation (1) for cooling at least one machine (4) or the like, characterized in that the decontamination consists in ensuring at least one aseptic filtration of circulating heat transfer fluid.   2) decontamination process according to claim 1, characterized in that the decontamination is still to provide a sterilizing filtration, or even a sedimentary filtration and / or absorbing circulating heat transfer fluid.   3) Decontamination process according to any one of the preceding claims, characterized in that it ensures the filtration of the heat transfer fluid upstream of the cooling tower (5), or between the machine (4) to cool using of this heat transfer fluid and this cooling tower (5).   4) decontamination process according to any one of the preceding claims, characterized in that it ensures the decontamination by filtering the heat transfer fluid contained in a reservoir (2) for supplying the cooling circuit (6) and that includes l cooling system (1).   5) Device (9) for decontaminating a heat transfer fluid circulating in a cooling circuit (6) and in a cooling tower (5) that comprises an installation (1) for cooling at least one machine (4) or the like, this device (9) being designed in particular to implement the method according to the preceding claims, characterized in that it comprises at least one means (10) for a sanitizing filtration of circulating heat transfer fluid.   6) Device (9) for decontamination according to claim 5, characterized in that it further comprises means (11) for sterilizing filtration, or even a means for ensuring sedimentary filtration (12) and / or means for providing absorbent filtration (13) of circulating heat transfer fluid.   7) Device (9) for decontamination according to claim 6, characterized in that the filtering means (10, 11, 12, 13) are arranged in series, within at least one set (19), or even a plurality of sets (19, 19A, 19B) in parallel, filtering means (10, 11, 12, 13).   8) Device (9) for decontamination according to any one of claims 5 to 7, characterized in that it comprises, on the one hand, a supply means (20) of the filtration means or (10, 11, 12, 13) of heat transfer fluid to be decontaminated and, on the other hand, a supply means (21) for the installation (1) of heat transfer fluid decontaminated by this or these filtration means (10, 11, 12 , 13).   9) Device (9) for decontamination according to claim 8, characterized in that the supply means (20) is constituted, on the one hand, by a conduit (22) for withdrawing heat transfer fluid to be decontaminated at the level of a tank (2) which comprises the installation (1), and, secondly, a pump (23) for sucking and conveying heat transfer fluid to be decontaminated to the filtration means or means (10, 11, 12, 13).   10) Device (9) for decontamination according to any one of claims 8 or 9, characterized in that the supply means (21) is constituted by a conduit (24) for supplying a reservoir (2), which comprises the cooling installation (1), a heat-exchange fluid decontaminated by the or the filtration means (10, 11, 12, 13).   11) Installation (1) for cooling at least one machine (4) or the like and comprising a cooling tower (5), a cooling circuit (6), a reservoir (2) supplying this circuit (6) and a heat transfer fluid, in particular water, circulating in this installation (1), characterized in that it comprises a device (9) for decontaminating the heat-transfer fluid, this device (9) being in accordance with the claims 5 to 10.