Method for treating cooling circuit water loaded with organic and inorganic particles - Patents.com

Abstract

The present invention relates to a method for treating cooling circuit water loaded with organic and inorganic particles of an industrial installation (2), in particular a hot rolling mill (2), comprising: a) separating organic and inorganic particles from cooling circuit water, thereby obtaining pre-purified cooling circuit water; b) cooling the pre-purified cooling circuit water through an open cooling tower (11), thereby obtaining cooled pre-purified cooling circuit water; c) desalting at least one partial volume flow of the cooled pre-purified cooling circuit water by means of at least one desalination stage (14), thereby obtaining purified cooling circuit water; d) adding bacteria suitable for decomposing organic matter present in the cooling circuit water before the separation according to step a), before the cooling according to step b) and / or before the desalination according to step c), thereby forming a biological purification stage; The present invention relates to a method for producing a medicament for a medicament comprising the steps of:

Description

[Technical field]

[0001] The present invention relates to The present invention relates to a method and an installation for treating cooling circuit water loaded with organic and inorganic particles in industrial installations, in particular in hot rolling mills. [Background technology]

[0002] In industrial installations, especially in hot rolling mills, large amounts of water are required to cool the process lines, the salts of which become concentrated in the course of the cooling process, so that a partial flow, the so-called blowdown water, is discharged and is usually either discharged directly or fed into the public sewer system.

[0003] Due to the increasing water shortage and the rising costs in the area of ​​water treatment plants, efforts are made to reduce the amount of blowdown water in order to achieve the highest possible fresh water savings. For this purpose, desalination plants are used in which the blowdown water is purified by reverse osmosis. In this case, it is certainly possible to recover high quality water with a high yield, but it has been found that the operational stability of the desalination plants is at risk, since the membranes used have a significantly shorter service life. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem underlying the present invention is therefore to provide a method and an installation which overcomes the drawbacks of the prior art, in particular to provide a method and an installation which improves the service life of membranes used in desalination plants. [Means for solving the problem]

[0005] According to the invention the problem is solved in a first aspect by means of the features of claim 1 as well as in a second aspect by means of the features of claim 12.

[0006] Further advantageous embodiments of the invention are set forth in the dependent claims. The features recited individually in the dependent claims may be combined with one another in a technically useful manner to define further embodiments of the invention. Furthermore, the features recited in the claims are specifically and explained in detail in the specification, which shows further preferred embodiments of the invention.

[0007] According to a first aspect, the present invention relates to a method for treating cooling circuit water loaded with organic and inorganic particles of an industrial installation, in particular a hot rolling mill, comprising: a) separating organic and inorganic particles from the cooling circuit water, thereby obtaining a pre-purified cooling circuit water; b) cooling the pre-purified cooling circuit water via an open cooling tower, thereby obtaining cooled pre-purified cooling circuit water; c) desalting at least one partial volume flow of the cooled pre-purified cooling circuit water by means of at least one desalting stage, thereby obtaining purified cooling circuit water; d) adding bacteria suitable for decomposing organic matter present in the cooling circuit water, said bacteria being added to said cooling circuit water before the separation according to step a), before the cooling according to step b) and / or before the desalination according to step c), thereby forming a biological purification stage; has.

[0008] Surprisingly, it has been found that the service life of membranes used in desalination plants can be significantly increased by adding bacteria to the cooling circuit water: by using bacteria, the service life of the membranes can advantageously be increased by at least 600%, particularly preferably by at least 900%, very particularly preferably by at least 1200% compared to conventional pretreatment of the blowdown water.

[0009] As bacterial cultures it is possible to use, for example, granules available from the applicant under the trade name "Oilco-Bacteria".

[0010] The key finding underlying the present invention is that the organic and inorganic particles contained in the cooling circuit water are not completely removed by conventional separation according to step a), and the fraction remaining in the cooled pre-cleaned cooling circuit water (blowdown water) - which is fed as at least a partial volumetric flow to the at least one stage desalination plant - significantly clogs the membrane, resulting in the significantly shorter service life observed.

[0011] Organic matter, especially fats and oils, combines with solid mineral-containing particles in the cooling circuit water, especially scales consisting mainly of iron (II, III) oxides, to form highly adhesive fine aggregates that irreversibly block the membrane. Here, scales with a particle size of 500 nm to 3000 nm in the blowdown water are covered with fats and oils. By the bacteria added to the cooling circuit, a biocenosis is formed in one or more areas of the cooling circuit, where the bacteria colonize and decompose or metabolize the organic matter, especially fats and oils, responsible for the adhesive properties of the fine aggregates. Thus, only bare scale particles remain in the cooling circuit water, which can no longer block the membrane due to the lack of adhesive properties.

[0012] A biocenosis in the sense of the present invention is a community of living organisms within a limited living space (biotope), and together biocenosis and biotope constitute an ecosystem.

[0013] According to the invention, bacteria are added to the cooling circuit water before the separation according to step a), before the cooling according to step b) and / or before the desalination according to step c). Thus, bacteria can be added to the cooling circuit water locally or distributed over the entire cooling circuit to form a biological purification stage. When bacteria are added over the entire cooling circuit, the advantage arises that each unit of the cooling circuit is almost free of sticky deposits, which usually have to be removed from the entire cooling circuit at regular intervals and disposed of separately. The removal of these deposits, which include organic matter as well as inorganic particles, can thus be reduced, which has a favorable effect on the ongoing operation costs of the installation. In this embodiment variant, the addition of biocides to the cooling circuit water is excluded, since the biocides would then destroy the biocenosis formed by the bacteria. If bacteria are added locally, in particular to the partial volumetric flow to be desalinated of the cooled, precleaned cooling circuit water, the addition of biocides to the remaining main volumetric amount can be advantageous. For this purpose, preferably biocides with only a little or, particularly preferably, no residual effect are used.

[0014] Regardless of the respective implementation variant, the main volume flow of cooled pre-cleaned cooling circuit water, which is transported from the open cooling tower in the cooling circuit section to the industrial installation via the main line, is preferably between 1000 and 30,000 m 3 / h. The partial volume flow of cooled precleaned cooling circuit water, which is fed from the main volume flow via a bypass line to at least one desalination stage, is preferably between 25 and 500 m 3 / h, more preferably 50 to 200 m 3 / h.

[0015] The invention likewise contemplates an installation for treating cooling circuit water loaded with organic and inorganic particles of an industrial installation, in particular a hot rolling mill. a) a separation device for separating organic matter and inorganic particles from the cooling circuit water to obtain pre-purified cooling circuit water; b) an open cooling tower capable of cooling the pre-purified cooling circuit water; c) at least one desalination stage capable of desalination of at least one partial volume flow of the cooled pre-purified cooling circuit water to obtain purified cooling circuit water; d) a metering device for adding bacteria suitable for decomposing organic matter present in the cooling circuit water, the metering device being arranged before the separator, before the cooling tower and / or before the desalination device so that a biological purification stage can be formed; has.

[0016] In an advantageous implementation variant, the residual amount of organic matter and / or inorganic particles contained in the partial volume flow (blowdown water) of the cooled precleaned cooling circuit water is separated before step c). If the concentration of the released solid inorganic particles has a very high value for the subsequent desalination, the inorganic particles can advantageously be separated first. Preferably, the separation of the released solid inorganic particles according to step b1) is carried out gravimetrically. Particularly preferably, it is provided that, based on the ferromagnetic properties of the inorganic particles, the separation according to step b1) is carried out by magnetic separation. By pre-separating the inorganic particles, the desalination membrane is protected and can be used longer, which has a favorable effect on the operating costs.

[0017] In another preferred embodiment, It is provided that nutrients are added to the cooling circuit water before step a), before cooling according to step b) and / or before desalination according to step c), which promote the growth of the added bacteria. The added nutrients promote the formation of biocenosis by the bacteria and furthermore encourage its long-term existence. Here, it is preferably provided that the ratio of added bacteria to added nutrients is reduced over time. Particularly preferably, it is provided in this connection that the addition of bacteria takes place depending on the formation of the biocenosis. For the initial formation of biocenosis in the cooling circuit, a higher concentration of bacteria is advantageous. A particularly preferred mixture of added bacteria and added nutrients therefore contains 1 wt. % bacteria and 99 wt. % nutrients. In contrast, for the maintenance of the already formed biocenosis, an increased concentration of nutrients is advantageous. Thus, the concentration of added bacteria decreases with increasing application time to less than 1 wt. %, while at the same time more than 99 wt. % nutrients are provided.

[0018] The bacteria are pure cultures of specific species that break down grease and fats: some species must be able to grow under anaerobic environmental conditions in order to be present in settling tanks and in the deeper layers of septic tanks, while others must be able to live aerobically in order to be able to remove grease and fats also in cooling towers and on the surface of septic tanks.

[0019] The nutrients are mainly nitrogen and phosphorus, with sulfur, potassium, magnesium and / or sodium also being used. A micronutrient mixture can also be part of the concentrate. This is a mixture of metals such as copper, nickel, cobalt, manganese, molybdenum, tungsten, zinc and / or tungsten, possibly supplemented with boron, silicon and / or selenium and possibly other elements and / or amino acids. Iron, which is usually included in the bacterial medium, is not necessary, as it is present in sufficient concentration in the cooling circuit, as is calcium.

[0020] In another advantageous embodiment variant, the bacteria and / or nutrients are provided in the form of granules and are added to the cooling circuit water in the form of an aqueous solution in the cooling circuit. The granules contain the bacteria and / or nutrients in concentrated form, which reduces the storage requirements. Expediently, the granules are dissolved in water. For this purpose, the water is preferably first heated to a temperature equivalent to the cooling circuit water. The granules are then dosed and a solution is formed. After an aging time of 3 to 6 h, the solution is added to the cooling circuit water. It has been found here that the diffusion of the bacteria and / or nutrients in the cooling circuit is significantly improved. Furthermore, in this connection, it is preferably provided that the bacteria in the granules are formed as lyophilized bacteria. Since lyophilized bacteria (freeze-dried bacteria) have a significantly longer life span, the granules can also be stored for longer periods.

[0021] In another preferred embodiment variant, the cooling circuit water loaded with organic and inorganic particles is led through a settling tank, a clarifier and / or a filter according to step a). In this connection, it is particularly preferred in the case of an embodiment variant in which bacteria are added to the cooling circuit water only before the separation according to step a) and / or before the cooling according to step b), that the bacteria are added to cooling circuit water with different environmental requirements, in particular anaerobic, anoxic and / or aerobic. The bacteria spread according to the respective environment and form a biocenosis in the respective installation part.

[0022] In a particularly preferred embodiment, the cooling circuit water purified according to step c), i.e. the desalinated blowdown water, is fed to the industrial plant, possibly after conditioning. This achieves a high degree of water saving. Another advantage is that the industrial plant can also be operated in areas that do not have a drainage channel nearby.

[0023] The term conditioning of the demineralized blowdown water, in the sense of the present invention, refers to the addition of corrosion inhibitors and, in some cases, the addition of an alkaline solution to control the pH value.

[0024] Preferably, the desalination according to step c) is carried out by reverse osmosis, capacitive deionization or thin-film evaporation. The desalination plant according to the invention is designed in at least one stage. However, it is preferably envisaged that the desalination plant is designed in one to two or four stages.

[0025] According to a particularly preferred embodiment variant, the bacteria are added only to a partial volume flow of the cooled precleaned cooling circuit water. For this purpose, the installation comprises a metering device arranged in a bypass line fluidly connecting the cooling tower with at least one stage of the desalination installation. In this connection, it is quite particularly preferably provided that the partial volume flow is led through a reactor used for forming a biological purification stage before the desalination in step c).

[0026] The reactor is preferably configured as a biological fixed bed reactor, trickling filter or trickle bed reactor. The reaction chamber of each reactor is filled with a suitable support material and can be flowed through. Fixed bed reactors provide very high conversion rates and further combine biological metabolic activity with the filtering action of the support material as a depth filter, whereby the oil is first retained in the bed and then metabolized by the bacteria. In other words, the bacteria form a biofilm on the surface of the support material, whereby the bacteria are at least partially protected from biocides and other bacteria-damaging influences.

[0027] The invention is not limited to the hot rolling mill installations detailed here but can in principle also be applied in other industrial sectors such as the food industry, refineries, chemical and pharmaceutical installations.

[0028] The present invention and technical environment are described in detail below with the drawings. It is pointed out that the present invention is not limited by the illustrated embodiments, and therefore should be used only for understanding the present invention. In particular, unless otherwise expressly stated, it is also possible to extract partial aspects of the matters illustrated in the drawings and combine them with other components and findings from this specification and / or the drawings. In particular, it is pointed out that the drawings and especially the illustrated dimensional relationships are only schematic. Since the same reference numerals indicate the same objects, in some cases, explanations from other drawings can be supplementarily cited. [Brief description of the drawings]

[0029] [Figure 1] Schematic diagram of a first embodiment variant of the installation for treating cooling circuit water loaded with organic and inorganic particles [Diagram 2] Schematic diagram of a second embodiment of the installation for treating cooling circuit water loaded with organic and inorganic particles [Diagram 3] Schematic diagram of a third embodiment of the installation for treating cooling circuit water loaded with organic and inorganic particles [Figure 4] Schematic diagram of a fourth embodiment of the installation for treating cooling circuit water loaded with organic and inorganic particles DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The plant 1 shown in Fig. 1 comprises, in the embodiment variant shown here, a hot rolling mill 2 to which a cooling circuit 3 is connected. The cooling circuit 3 comprises a number of units which are fluidly connected to one another and which are described in more detail below.

[0031] As shown, the hot rolling mill 2 is firstly connected to a cooling circuit 3, so that the cooling circuit water used in the hot rolling mill 2, loaded with organic matter such as fats and oils, and especially inorganic particles such as scale, is treated to such an extent that it can be fed directly back to the hot rolling mill 2 via units arranged in the cooling circuit 3. If the amount of cooling circuit water falls below a certain volume, additional fresh water is added to the cooling circuit 3 via fresh water supply 4. The fresh water can optionally be doped with biocides, hardness stabilizers, flocculating and precipitating agents and other additives.

[0032] The installation 1 shown in FIG. 1 firstly comprises a separation device 5 for separating organic and inorganic particles from the cooling circuit water of the hot rolling mill 2, so that a pre-cleaned cooling circuit water is obtained. As can be seen from FIG. 1, the separation device 5 comprises several components connected in series. In the embodiment shown, the separation device 5 comprises a settling tank 6 for separating the coarse fraction of the mixture of organic and inorganic particles, a clarifier tank 7 for separating the average size of the mixture of organic and inorganic particles, and a filtration device 8, which usually comprises several filtration units. It is noted that in this figure, only two parallel-connected filtration units 9, 10 of the several filtration units of the filtration device 8 are shown. In both filtration units 9, 10, the fine fraction of the mixture of organic and inorganic particles is separated. Each of the two filtration units 9, 10 of the filtration device 8 is formed in the form of a gravel filter in this embodiment.

[0033] Furthermore, the plant 1 shown in FIG. 1 has an open cooling tower 11, via which the pre-purified cooling circuit water can be cooled. In the cooling tower 11, the pre-purified cooling circuit water is atomized, whereby an aerosol is formed, which then condenses and is thereby cooled. The cooled pre-purified cooling circuit water thus obtained (so-called blowdown water) is divided into a main volume flow and a partial volume flow. In this case, the main volume flow is fed via a main line 12 to the hot rolling mill 2. The partial volume flow is fed via a bypass line 13 to at least one desalting plant 14 and desalted to obtain purified cooling circuit water, which is then fed via a return line 15 to the hot rolling mill 2. This achieves a high degree of water saving. Another advantage is that the plant 1 can also be operated in areas with little groundwater or river water in the immediate vicinity.

[0034] Desalination is preferably carried out by the principles of reverse osmosis, capacitive deionization or thin-film evaporation.

[0035] In the cooling circuit 3, the plant 1 further comprises a dosing device 16 for adding bacteria suitable for decomposing organic matter present in the cooling circuit water. The bacteria are formed here as freeze-dried bacteria. The dosing device 16 can be arranged before the separation device 5, before the cooling tower 11 and / or before the desalination plant 14.

[0036] Alternatively, the metering device 16 can also be arranged in the separation device 5 before the settling tank 6, before the clarification tank 7 and / or before the filtration device 8 (not shown).

[0037] In the embodiment variant shown here (FIG. 1), the plant 1 has a first metering device 17 arranged before the separation device 5 and a second metering device 18 arranged before the cooling tower 11, via which bacteria are added to the cooling circuit 3.

[0038] By adding bacteria to the cooling circuit water, the service life of the membranes (not shown) used in the desalination plant 14 is significantly increased. This is because the organic matter, especially fats and oils, and inorganic particles, especially scale, mainly consisting of iron (II, III) oxides, contained in the cooling circuit water form highly sticky fine aggregates that cannot be completely removed by the separation device 5. By the bacteria added to the cooling circuit 3, the organic matter, especially fats and oils, responsible for the adhesive properties of the fine aggregates, are decomposed or metabolized, so that the scale particles, which are bare in the cooling circuit water, can no longer block the membrane due to their lack of adhesive properties. In addition, when bacteria are added throughout the cooling circuit 3 as shown here, the advantage arises that any unit of the cooling circuit has almost no sticky deposits, which normally have to be removed from the entire cooling circuit 3 at regular intervals and disposed of separately. The removal of these deposits, including organic matter as well as inorganic particles, can therefore be reduced, which has a favorable effect on the ongoing operating costs of the plant 1. In this embodiment variation, the addition of biocides to the cooling circuit water is excluded, since the biocides would then destroy the biocenosis formed by bacteria in the settling tank 6, in the clarifier 7, in the filter 8, in the cooling tower 11 and in the respective lines.

[0039] In addition, nutrients are added to the cooling circuit 3 via both dosing devices 17, 18, which promote the growth of the added bacteria. The added nutrients promote the formation of a biocenosis by the bacteria and further encourage its long-term existence. It is preferably provided here that the ratio of added bacteria to added nutrients is reduced over time. Particularly preferably, it is provided in this connection that the addition of bacteria takes place depending on the formation of the biocenosis. For the initial formation of the biocenosis in the cooling circuit 3, a higher concentration of bacteria is advantageous. A particularly preferred mixture of added bacteria and added nutrients contains 1 wt.-% bacteria and 99 wt.-% nutrients. In contrast, for the maintenance of the already formed biocenosis, an increased concentration of nutrients is advantageous. Thus, with increasing application time, the concentration of added bacteria falls below 1 wt.-% and at the same time more than 99 wt.-% nutrients are provided. The bacteria and nutrients are provided in the form of granules and are added in the form of an aqueous solution to the cooling circuit water in the cooling circuit 3 via both dosing devices 17,18.

[0040] The bacteria added to the cooling circuit water here have different environmental requirements: thus, the settling tank 6 is operated anaerobically, the septic tank 7 is operated anaerobically or aerobically, the filter 8 is operated anaerobic aerobic and the cooling tower 11 is operated aerobically.

[0041] Figure 2 shows a second implementation variant of the installation 1 according to the invention. In contrast to Figure 1, the installation 1 has a second separator 19 arranged in the bypass line 13 between the cooling tower 11 and the desalination installation 14. If the concentration of released solid scale particles in the blowdown water has a very high value for the subsequent desalination, the scale particles can advantageously be separated first by the second separator 19. Since the scale particles have ferromagnetic properties, the separation can in this case also be carried out by magnetic separation in addition to the usual sedimentation. By pre-separation of the scale particles, the desalination membrane is protected and can be used longer, which advantageously has a favorable effect on the operating costs.

[0042] Figure 3 shows a third embodiment variant of the plant 1 according to the invention. In contrast to the embodiment variant shown in Figure 1, bacteria are added locally to the cooling circuit water via a third metering device 20. As shown, according to this embodiment variant, bacteria are added only to a partial volume flow of the blowdown water in order to dissolve highly sticky fine aggregates composed of organic matter, in particular fats and oils, and inorganic particles, in particular scales, mainly consisting of iron (II, III) oxides, for subsequent desalination. For this purpose, the plant 1 has a reactor 21 arranged downstream of the third metering device 20, in which biocenosis is formed. The reactor 21 in the embodiment variant shown here is a biological fixed-bed reactor.

[0043] Since the cooling circuit arranged upstream of the third metering device 20 is therefore not subject to biological purification, in the embodiment variant shown here, biocides as well as other additives are added via both metering devices 17, 18. Here, the biocides are metered into the cooling circuit at intervals. In order to avoid suppression of biocenosis in the reactor 21, the bypass line 13 and the return line 15 are advantageously blocked via shutoff valves (not shown) until the concentration peak has been distributed in the system and has reached a stable value after about 3 hours.

[0044] Finally, FIG. 4 shows a fourth embodiment variant of the installation 1 according to the invention which, in contrast to the previous embodiment variant (FIG. 3), like the embodiment variant shown in FIG. 2, has a second separation device 19 for removing inorganic scale components which are arranged downstream of the reactor 21 in the bypass line 13 and which are used for desalting in the desalting stage.

[0045] The present invention is not limited to the combinations of features defined in the dependent claims, but may also be defined by any other respective combination of given features of all the individual features disclosed as a whole. This means that in principle essentially each individual feature of the independent claims may be omitted or may be replaced by at least one individual feature disclosed elsewhere in the application. In that respect, the independent claims should only be understood as a first attempt to express the invention. [Explanation of symbols]

[0046] 1 equipment 2. Industrial Equipment / Hot Rolling Mill 3 Cooling circuit 4 Fresh water supply 5 Separation device 6 Sedimentation tank 7. Septic tank 8 Filtration device 9 Filtration Unit 10 Filtration unit 11 Cooling Tower 12 Main Line 13 Bypass Line 14 Desalination equipment 15 Return Line 16 Dosing device 17 First dispensing device 18 Second dispensing device 19 Second Separation Device 20 Third dispensing device 21 Reactor

Claims

1. 1. A method for treating cooling circuit water loaded with organic matter, including fats and oils, and inorganic particles, including scale, mainly consisting of iron (II, III) oxides, in the cooling circuit of an industrial installation (2), in particular a hot rolling mill (2), comprising: a) separating organic and inorganic particles from cooling circuit water, thereby obtaining pre-purified cooling circuit water; b) cooling the pre-purified cooling circuit water via an open cooling tower (11), thereby obtaining cooled pre-purified cooling circuit water; c) desalting at least one partial volume flow of the cooled pre-purified cooling circuit water in at least one desalting installation (14) using a membrane, thereby obtaining purified cooling circuit water; d) adding bacteria to the cooling circuit suitable for decomposing fats and oils contained in the organic matter present in the cooling circuit water before the separation according to step a), before the cooling according to step b) and / or before the desalination according to step c), thereby forming a biological purification stage consisting of biocenosis in one or more areas of the cooling circuit; The method of claim 1, further comprising:

2. 2. The method according to claim 1, characterized in that prior to step c), residual amounts of organic matter and / or inorganic particles contained in the partial volume flow of cooled pre-purified cooling circuit water are separated (step b1).

3. 3. The method according to claim 2, characterized in that the separation according to step b1) is carried out gravimetrically.

4. 4. The method according to claim 2 or 3, characterized in that the inorganic particles are ferromagnetic and that the separation according to step b1) is carried out by magnetic separation.

5. 5. The method according to claim 1, characterized in that before the separation according to step a), before the cooling according to step b) and / or before the desalination according to step c), nutrients are added to the cooling circuit water, which nutrients promote the growth of the added bacteria, and preferably the ratio of added bacteria to added nutrients is reduced over time.

6. 6. The method according to claim 5, characterized in that the bacteria and / or nutrients are provided in the form of granules and are added to the cooling circuit water in the form of an aqueous solution, the bacteria in the granules being preferably formed as freeze-dried bacteria.

7. 7. The method according to claim 1, wherein the cooling circuit water loaded with organic and inorganic particles is led according to step a) through a settling tank (6), a clarifier tank (7) and / or a filtration device (8).

8. 8. The method according to claim 1, wherein the cooling circuit water purified in step c) is supplied to an industrial installation (2), optionally after conditioning.

9. 9. The method according to claim 1, wherein the desalting according to step c) is carried out by reverse osmosis, capacitive deionization or thin-film evaporation.

10. 10. The method according to claim 1, wherein the bacteria are added only to a partial volume flow of the cooled pre-purified cooling circuit water.

11. 11. The method according to claim 10, characterized in that a partial volume flow is conducted through a reactor (21) used to form a biological purification stage prior to the desalination according to step c).

12. An installation (1) for treating cooling circuit water loaded with organic matter, including fats and oils, and inorganic particles, including scale, mainly consisting of iron (II, III) oxides, in the cooling circuit of an industrial installation (2), in particular a hot rolling mill (2), comprising: a) a separation device (5) for separating organic and inorganic particles from the cooling circuit water in order to obtain pre-purified cooling circuit water; b) an open cooling tower (11) capable of cooling the pre-purified cooling circuit water; c) at least one desalination stage (14) capable of desalination by means of a membrane of at least one partial volume flow of the cooled pre-purified cooling circuit water to obtain purified cooling circuit water; d) a metering device (16, 17, 18, 20) for adding bacteria to the cooling circuit suitable for decomposing fats and oils contained in the organic matter present in the cooling circuit water, the metering device (16, 17, 18, 20) being arranged before the separation device (5), before the cooling tower (11) and / or before the desalination device (14) so ​​that a biological purification stage consisting of biocenosis can be formed in one or more areas of the cooling circuit; The facility (1) comprises:

13. 13. Installation (1) according to claim 12, characterized in that the metering device (16, 20) is arranged in a bypass line (13) connecting the cooling tower (11) with at least one desalination stage (14).

14. 14. The plant (1) according to claim 13, further comprising a reactor (21) arranged in the bypass line (13) upstream of the at least one desalination stage (14) and intended to form a biological purification stage.

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