PROCESS FOR DEGRADING ORGANIC FRACTIONS IN COOLING CIRCUITS OF INDUSTRIAL PLANTS, AND COOLING CIRCUIT FOR AN INDUSTRIAL PLANT

Abstract

A method for degrading organic fractions in cooling circuits in industrial plants, in particular plants in the metallurgical industry, including the following steps: adding bacteria to the cooling circuit, wherein the bacteria are suitable for degrading the organic fractions in the cooling circuit, and disinfecting the aerosol generated in a cooling tower of the cooling circuit. A cooling circuit for an industrial plant is also disclosed.

Claims

1-21. (canceled)

22. A method for degrading organic fractions in cooling circuits of industrial plants, in particular of plants in the metallurgical industry, comprising: adding bacteria to the cooling circuit, wherein the bacteria are suitable for degrading the organic fractions in the cooling circuit, and disinfecting the aerosol generated in a cooling tower of the cooling circuit.

23. The method according to claim 22, wherein the disinfecting comprises the adding of a locally acting chemical disinfectant.

24. The method according to claim 23, comprising removing excess chemical disinfectant from the coolant circuit after the cooling tower passage.

25. The method according to claim 22, comprising circulating steam at a temperature ≥70° C. through the cooling tower of the cooling circuit for heating and disinfecting the aerosol generated in the cooling tower.

26. The method according to claim 22, wherein bacteria with different environmental requirements, in particular anaerobic, anoxic, and/or aerobic, are added to the cooling circuit.

27. The method according to claim 22, further comprising the adding of nutrients to the cooling circuit, in particular nutrients for the added bacteria.

28. The method according to claim 27, comprising the step of adapting the ratio between added bacteria and added nutrients over time, in particular reducing the added bacteria and increasing the added nutrients over the application time of the method.

29. The method according to claim 22, wherein the steps of adding bacteria and/or disinfecting are repeated at regular or irregular intervals.

30. The method according to claim 26, wherein the intervals between the repetitions becomes greater as the application time of the method increases.

31. The method according to claim 22, comprising the step of taking a sample from the cooling circuit and determining the concentration of Legionella.

32. The method according to claim 31, wherein the sampling is repeated regularly or irregularly, wherein the intervals between the sampling preferably become greater as the application time of the method increases.

33. The method according to claim 22, wherein the method is started in the winter months.

34. The method according to claim 22, wherein the bacteria and/or nutrients are provided in the form of granules, wherein the granules are dissolved in water before being added to the cooling circuit.

35. The method according to claim 34, wherein the granules contain lyophilized bacteria.

36. A cooling circuit for an industrial plant, in particular for plants in the metallurgical industry, comprising: a thermal coupling to the industrial plant, and a cooling tower for cooling the coolant in the cooling circuit, wherein the cooling circuit contains bacteria for degrading organic fractions, and the cooling tower has a device for disinfecting the aerosol generated in the cooling tower.

37. The cooling circuit according to claim 36, wherein the device for disinfecting the aerosol generated in the cooling tower is formed as a dispensing device for a chemical disinfectant.

38. The cooling circuit according to claim 37, wherein a device for removing excess chemical disinfectant is arranged in the cooling circuit after the cooling tower passage.

39. The cooling circuit according to claim 36, wherein the device for disinfecting the aerosol generated in the cooling tower is formed as a steam-generating unit for generating steam at a temperature ≥70° C.

40. The cooling circuit according to claim 36, further comprising at least one metering device for dispensing bacteria and/or nutrients to the cooling circuit.

41. The cooling circuit according to claim 36, further comprising a sedimentation tank, a clarifying tank, and/or a filter.

Description

[0041] In the following, the invention will be explained in greater detail by means of the exemplary embodiment illustrated in the figure. The following is shown:

[0042] FIG. 1 a schematic view of a cooling circuit according to the invention.

[0043] The cooling circuit 1 according to the invention for an industrial plant 2 from FIG. 1 comprises a thermal coupling 3 to the industrial plant 2, a cooling tower 4, a sedimentation tank 5, a clarifying tank 6, and two filters 7. Coolant 8, preferably water, flows through the cooling circuit 1.

[0044] According to the invention, the cooling tower 4 of the cooling circuit 1 comprises a device for disinfecting the aerosol generated in the cooling tower 4. According to the exemplary embodiment from FIG. 1, the disinfection device is formed as a steam-generating unit 9 for generating steam at a temperature of 70° C. The cooling circuit 1 also comprises two metering devices 10 for dispensing bacteria and/or nutrients to the cooling circuit 1.

[0045] The heat generated in the industrial plant 2 is intended to be dissipated via the cooling circuit 1 according to the invention. For this purpose, the heat is transferred from the industrial plant 2 to the cooling circuit 1, in particular the coolant 8 located in the cooling circuit 1, via the thermal coupling 3. The heat transfer can take place directly or indirectly.

[0046] The coolant 8 is then cleaned in the sedimentation tank 5, the clarifying tank 6, and the two filters 7 before it is cooled in the cooling tower 4. The cooled coolant 8 can then be supplied back to the thermal coupling 3 or, in the case of water, for example, it can be released into the environment.

[0047] The organic fractions in the cooling circuit 1 form deposits 11, for example in the form of sludge, in particular in the sedimentation tank 5 and clarifying tank 6. These deposits have to be removed from the sedimentation tank 5 and clarifying tank 6 in a laborious manner and then disposed of separately, which is associated with correspondingly high costs.

[0048] According to the invention, it is therefore provided that bacteria are added to the cooling circuit 1, in particular the coolant 8, the bacteria being suitable for degrading the organic fractions present in the cooling circuit 1. Organic fractions are, in particular, oils and fats, which combine with solid particles in the cooling circuit 1 and thereby produce the deposits 11. The added bacteria preferably have different environmental requirements, such as anaerobic, anoxic, and/or aerobic, so that they can settle in different areas of the cooling circuit 1 and develop a biocenosis. For example, the sedimentation pit 5 is anaerobic, the clarifying tank 6 is aerobic, the filters 7 are anoxically aerobic, and the cooling tower 4 is aerobic.

[0049] According to an advantageous variant of the invention, nutrients for the added bacteria can also be added to the cooling circuit 1, in particular the coolant 8. These nutrients promote the growth of bacteria and thus the development of a corresponding biocenosis.

[0050] The ratio between added bacteria and added nutrients can be adapted over time, in particular the added bacteria are reduced and the added nutrients are increased.

[0051] The adding of bacteria and/or nutrients can be repeated at regular or irregular intervals, the intervals between the repetitions preferably increasing as the duration of the application increases.

[0052] The added bacteria significantly reduce the organic fractions in the cooling circuit 1, which leads to a significantly lower formation of deposits 11.

[0053] To ensure that the Legionella concentration in the cooling circuit 1 can be kept below a prescribed limit value, the cooling tower 4 of the cooling circuit 1 comprises the disinfection device formed as a steam-generating unit 9. By means of the steam-generating unit 9, steam, preferably water vapor, can be circulated through the cooling tower at a temperature of 70° C. As a result, the Legionella contained in the aerosol formed by the cooling tower 4 are effectively killed off, such that the Legionella concentration in the cooling circuit 1 can be reduced.

[0054] Samples are expediently taken from the cooling circuit 1, in particular from the coolant 8, at regular or irregular intervals, and the Legionella concentration is determined. If the Legionella concentration exceeds the specified limit value, steam, which is 70° C. or hotter, is circulated through the cooling tower 4 by means of the steam-generating unit 9 in order to kill off the Legionella in the generated aerosol.

[0055] As the operating time of the cooling circuit 1 increases, the intervals between the sampling can be increased, since the breeding sites for Legionella are reduced due to the fewer deposits.

[0056] The steam-generating device 1 is expediently arranged in the lower region of the cooling tower 4 so that the generated steam can rise while the aerosol generated in the cooling tower 4 falls. A good heat exchange takes place through these opposing flows.

[0057] The bacteria and/or nutrients are preferably provided in the form of granules, the granules being dissolved in water before being added to the cooling circuit 1. Since the granules contain the bacteria and/or nutrients in concentrated form, the storage requirements are reduced. The granules are expediently dissolved in water at a temperature comparable to that of the coolant 8 in the cooling circuit 1, as a result of which the propagation of the bacteria and/or nutrients in the cooling circuit 1 is improved. The granules advantageously contain lyophilized bacteria. Lyophilized bacteria (freeze-dried bacteria) have a significantly longer shelf life, so that the granules can also be stored for longer periods of time.

LIST OF REFERENCE NUMERALS

[0058] 1 Cooling circuit [0059] 2 Industrial plant [0060] 3 Thermal coupling [0061] 4 Cooling tower [0062] 5 Sedimentation tank [0063] 6 Clarifying tank [0064] 7 Filter [0065] 8 Coolant [0066] 9 Steam generator [0067] 10 Metering device [0068] 11 Deposit