Device and method for purifying cleaning fluids used in breweries

p0001The invention relates to a method and an apparatus for treating, in particular for cleaning bottles or in CIP systems, eg. As in the brewhouse i n breweries obtained cleaning liquids.

p0002In breweries Sudgefäßreinigung takes place, as well as bottle washing, using cleaning solutions. Bottles, for example, a bottle washing plant as very schematically in<figref idrefs="f0003">figure 3</figref> is shown cleaned. Such bottle washers 10 include, as will be described in detail, for example, a Vorlaugebad 32, a main caustic bath 28, and a 37 Nachlaugebad first rinsing zone. In bottle cleaning, however, the state of the cleaning solution deteriorates despite feathering because settles more and more sludge and soluble, insoluble or colloidal suspensions that are contained in the liquor. These include paper fibers from shredded labels, color pigments, binder of labels, wet strength agents, sizing agents, precipitated sludge of lime constituents, adhering dirt from bottles etc. When cleaning Sudhausgefäßen among others fall more spent grains and Trubrestmengen and debris from the cooking vessels for mash and wort boiling on.

p0003When cleaning liquid not only cleaning solutions are used. In particular in CIP systems as cleaning fluids and acids and disinfectants used, which must be cleaned especially the sludge that settles to the bottom of the CIP tank must be drained before each purification step in the channel.

p0004The preparation of the corresponding cleaning liquids are now increasingly by filtration. The cleaning equipment used in the prior art, however, the problem arises that the filter surfaces, in particular by the large amounts of impurities such as paper fibers by label residues, spent grains and Trubresten enforce after a short time. Such cleaning systems are therefore very maintenance-intensive and can not be operated continuously. pollution in the cross-flow filtration circuit are feedback container used with large volumes Especially in the cross-flow filtration of cleaning liquid to prevent the concentration. This has the disadvantage that the large tank volume must be discarded at the end of the week. The large volumes in the filtration unit lead to increased heat radiation and reduced availability because refilling the tub of the bottle washer is necessary to start up the filtration system, which means considerable downtimes during filling.

p0005Proceeding from this, the present invention seeks to provide an apparatus and method for processing cleaning liquids to easy, environmentally friendly and continuously clean the heavily soiled cleaning liquids.

p0006According to the invention this object is achieved by the features of claims 1 and 10. FIG.

p0007Through a combination of coarse and fine filters and micro filter results in the advantage that the filter assembly, in particular the cross-flow filter (fine filter) added not so fast. In swift way a cross-flow filter is used. The term cross-flow filter is a technical term and designates filters in which the unfiltered material flows parallel along a filter membrane. A portion of the unfiltered penetrates transversely to the direction of flow of the unfiltered and the membrane can be derived as a filtrate. Here, solids of the unfiltered are deposited on the membrane of the filter. With the parallel flow onto the membrane, the depositing solids are continuously entrained by the liquid flow so that on the membrane a balance between new deposits and cleaning of the membrane is achieved.

p0008According to the invention, a return line is provided, ie the coarse filtrate of the coarse filter out the coarse filtered cleaning fluid circulated through the cross-flow filter. Thus, a sufficient flow and a high filter efficiency can be ensured. In order to prevent skilfully the concentration of impurities of the recycled coarse filtrate, a derivative is provided, which branches off from the circuit, in particular of the return line and is connected to a backwashing. Thus it can be used for backwashing the coarse filter in a skillful way the concentrated impurity cleaning fluid. This means that a concentration of pollution can be prevented on the one hand by the discharge of the coarse filtrate, on the other hand this coarse filtrate derived is used in an efficient manner for backwashing and need not be discarded. The present invention allows that no additional tank for buffering the concentrate configuration is necessary. This has the further advantage that no large tank volume must be discarded at the end of the week. Because the system does not have a large tank volume, the whole system may be under pressure, resulting in minimized pump powers result. Small filling volumes offer the additional advantage that the availability of, for example, a bottle washer, increasing as refilling the bottle washer at the start of the filtration system is not necessary. A further advantage is that, for example, both for the treatment of post-caustic and used for treatment of major liquor a bottle washer, the same flowsheet is applicable. This allows for a simplified production, in which depending on the application, only the cross-flow filters, ie the pore width of the respective membrane, must be adjusted. Under cleaning liquids both cleaning solution and cleaning acid or disinfectant must be understood.

p0009Advantageously, the device is arranged at least two parallel, flushable alternating coarse filter on. Thus, a continuous process can be ensured because even if one of the coarse filter is being backwashed and cleaned, the second coarse filter in use. Inasmuch as the circulated coarse filtrate is used for backwashing, can therefore often backwashing will be performed, what the filter efficiency improved. The process must not be interrupted.

p0010Advantageously, the coarse filter particles of a size filtered out> 50 microns. The cross-flow filter has depending on the application on a pore size in a range of <= 2 .mu.m, preferably <= 0,4μm. According to a preferred embodiment of a disc filter can be used as a coarse filter. Such a disc filter is backwashed just.

p0011According to a preferred embodiment, the device prepares a scrubber liquor main liquor from a main caustic bath of a bottle washer and includes a Feinfiltratleitung which again feeds the fine filtrate from the cross flow filter to the main caustic bath. The device is also well suited for the processing of post-caustic from a Nachlaugebad a bottle washer and includes a Feinfiltratleitung which again feeds the fine filtrate from the cross-flow filter the Nachlaugebad.

p0012When processing of main caustic circle, another branch line include for discarding a portion of the recycled coarse filtrate. Thus, if the concentration of impurities in the cross-flow filter circuit is too large, in addition, a portion of the recycled coarse filtrate may be branched off and discarded, so that the concentration of the impurity decreases. Thus, an excessive Gelschichtbildung on the membrane surface of the cross-flow filter and a premature clogging can be prevented.

p0013In the purification of the post-caustic circuit may also include a further branch line for supplying a part of the circulated to a coarse filtrate Vorlaugebad. Thus, the concentration of impurities in the membrane filtration circuit can be prevented in an advantageous manner, the coarse filtrate can be used simultaneously or for the Vorlaugebad because the cleaning solution in Vorlaugebad not be so heavily filtered.

p0014According to the present invention, the cleaning solution or acid or disinfecting fluid can be prepared from a CIP system as a cleaning liquid, the fine filtrate is then fed to a corresponding caustic or acid or disinfecting liquid tank.

p0015In the present process continuously, a certain portion of the recycled coarse filtrate are discharged. The discharged part of the coarse filtrate may also be discharged clocked at certain intervals during the filtration process.

p0016The present invention is explained in more detail with reference to the following figures.<ul><li><figref idrefs="f0001">figure 1</figref> schematically illustrates the flow diagram of a device according to the present invention.</li><li><figref idrefs="f0002">figure 2a</figref> schematically shows a section through a disc filter, which is used in the inventive device.</li><li><figref idrefs="f0002">figure 2b</figref> schematically shows a plan view of a disk of the in <figref idrefs="f0002">figure 2a</figref> shown disc filter. </li><li><figref idrefs="f0003">figure 3</figref> schematically shows the different stages of a bottle washing machine.</li><li><figref idrefs="f0004">figure 4</figref> roughly schematically shows a section through a cross-flow filter.</li><li><figref idrefs="f0004">figure 5</figref> shows a section along the line II in <figref idrefs="f0004">figure 4</figref>,</li><li><figref idrefs="f0004">figure 6</figref> shows in perspective a Multitubemembranfilterkerze, for example, in the in <figref idrefs="f0004">figure 4</figref> shown filter is used.</li><li><figref idrefs="f0005">figure 7</figref> schematically shows the basic scheme of a CIP system.</li></ul>

p0017According to the present invention are for treating the resulting breweries contaminated cleaning fluids a flushable coarse filter, for example, a disk filter 2, used in combination with a cross-flow filter. 3

p0018A disc filter is for example in the <figref idrefs="f0002">Figures 2a and 2b</figref> shown. The disc filter comprises a filter housing 20, and a nonfiltrate 21 and a Grobfiltratablauf 22 via the inflow 21 is the disk filter 2 is supplied according to the present invention, the cleaning liquid. The disc filter 2 has a plurality of superposed filter discs 17th As from<figref idrefs="f0002">figure 2b</figref> shows the filter discs 17 are constructed as a filter rings. The disks 17 are pressed together by the spring force of the spring 19th The disks have at least one side to a corrugation 18th Advantageously, the grooves or projections 18 extend substantially radially outwardly. The corrugation of the superposed discs 17 thus result in the filter pores, through which the unfiltered fluid passes through the filter. Preferably, here come plastic discs used. The unfiltered material is introduced to the filtration through the inlet 21, for example, tangentially from the outside and passes, as indicated by the arrows, the pores between the individual filter discs 17. The filtrate is then discharged from the interior 23 of the disc filter via the outlet 22nd During backwashing an air-liquid mixture is, for example, fed into the interior 23 and pressed against the arrow between the filter discs from the filter. Simultaneously, the pressure of the discs 17 is loosened by reducing the spring force. The filter pores are thereby enlarged and simultaneously the individual disks are offset by the backwashing in rotation. Thus, an optimum cleaning of the filter surface is ensured.

p0019the filter fineness is preferably about 50 microns. With a filter fineness of 100 microns about 50% of the fibers are deposited in the wash water filtration yet.

p0020As described in connection with the <figref idrefs="f0004">Figures 4 - 6</figref> illustrates a cross-flow filter 3 is used for fine filtration or microfiltration. For continuous operation with small cut-offs with membranes as a filter layer, the surface filtration is a useful initial constellation. In the cross-flow filtration, the coarse filtrate from the coarse filter 2a / b flowing the liquid to be filtered, so here parallel to the filter membrane along. The pressure prevailing in the system overpressure ensures the penetration of a portion of the unfiltered, here the coarse filtrate through the membrane transversely to the direction of flow of the coarse filtrate. Here, the entrained solids of the unfiltered, ie the coarse filtrate on the membrane to store. With the parallel flow onto the membrane, the depositing solids are continuously entrained by the liquid substance and on the membrane a balance between new deposits and cleaning of the membrane is achieved. The the depositing materials on the membrane, which are not carried away by the flow of liquid, form the so-called gel layer.

p0021In <figref idrefs="f0004">Figures 4 - 6</figref> is a possible embodiment of such a cross-flow filter 3 shown, wherein the filter case comprises a pressure housing 42 as well as at least one Multitubemembranfilterkerze 40th a filtrate forms 43. Between the membrane filter cartridge 40 and the pressure housing 42 Multitubemembranfilterkerze 40 has as in<figref idrefs="f0004">Figures 5 and 6</figref> is shown in more detail, a plurality of tubes 21 extending longitudinally through the filter candle 40th The filter cartridge may be formed from a ceramic material, which can be arranged on the tube inside a little .mu.m thick membrane layer. The pore size is in the range of &lt;= 2 .mu.m, preferably &lt;= 0,4μm, depending on the application. In the filtration occurs unfiltered material, here coarse filtrate from the coarse filter 2 a / b in the tubes 21 of the filter candle 40, passes through the membrane in the tubes 21 and the ceramic of the filter cartridge, and leaves the surface 41 of the filter cartridge 40 as filtrate, and enters the filtrate space 43, where it can be removed as filtrate. The unfiltered material that flows through the tubes 21 exits the cross-flow filter 3 and can be fed back to the cross-flow filter in the loop to maintain a stream of unfiltered material through the filter as described below will be explained in more detail. Since when cleaning in breweries and hot cleaning liquids are used, the temperatures have up to 90 ° C, a cross-flow filter arrangement of ceramic material is particularly suitable.

p0022The apparatus and method of the invention can, for example, for cleaning liquids from CIP systems, are used for brewhouse or for cleaning in the bottling hall example.

p0023The inventive method and the inventive device will now be in particular in connection with the in <figref idrefs="f0003">figure 3</figref> Bottle cleaning installation illustrated explained in detail.

p0024<figref idrefs="f0003">figure 3</figref> shows the main stages of a bottle washer with a bottle infeed 53. After emptying the bottles pass successively through the pre-soak 34 and the pre-soak 35 and then pass the Vorlaugebad. Thereafter, the longest and most intensive treatment is performed in main caustic bath 28 where solve most of the dirt and most of the impurities. This also applies to the labels and the Etikettierleim. In a Nachlaugebad 37, ie a first rinsing zone, the bottles are again cleaned inside and out and can then with a spray device 38/39 with hot water inside and outside are sprayed. a treatment with cold and fresh water in a corresponding device 50. Subsequently, at the end of the bottles will be delivered via a bottle discharge 54th

p0025The inventive apparatus for processing cleaning liquid, here. B. Main liquor or Nachlage or a cleaning liquid to a CIP system is in <figref idrefs="f0001">figure 1</figref> shown.

p0026The invention for cleaning solution z. B. Main liquor or post-caustic is described. This in connection with<figref idrefs="f0001">figure 1</figref> Described method and apparatus is however also suitable for other cleaning liquid, such as a brewery CIP system.

p0027The device is connected via a line 24 to a reservoir for the cleaning solution, such as a main caustic bath or a Nachlaugebad. Further, the apparatus comprises a pump 9 via which the cleaning solution can be pumped into the inventive device. In addition, the inventive device 1 here comprises two coarse filter 2a / b, which are arranged parallel to each other. The coarse filters 2a / b are for example disk filters as they related to the<figref idrefs="f0002">2a</figref>/ B were explained in detail. The coarse filters 2a / b filter out particles of a size> 50 microns. Here, if also not shown, a plurality of coarse filter may be arranged parallel to one another and operated alternately for cleaning purposes. Although not shown, a plurality of coarse filter could be connected in series to several 2a 2b coarse filters in series parallel.

p0028After the rough filtration, the coarse filtrate is led to membrane filtration as shown by the arrow G. Before the cross-flow filter 3, for example, in connection with<figref idrefs="f0004">Figure 5 - 6</figref> has been described, a pump 10 is arranged. The cross-flow filter 3 comprises a filtrate removal line 7, in which in turn the valve 16 is arranged. The apparatus further umfass a return conduit 4 through which the coarse filtrate is passed through the cross-flow filter 3 in a circle K. Terminating the flow a control valve 15 is provided. Thus, the coarse filtrate moves at the membrane or the membranes through the cross-flow filter 3 through, leaves the filter 3 and the cross-flow filter 3 is circulated through the pump 10 fed back and together with a new coarse filtrate from the coarse filters 2a / b. The apparatus further comprises a Rückspürleinrichtung 5 for backwashing the coarse filter 2a / b. As flushing liquid the circle K circulating coarse filtrate is used here in an advantageous manner. For this, a discharge line 6 is provided, which is connected to the backwashing fifth Thus, a predetermined portion of the circulated unfiltered material or coarse filtrate is fed into a washing container of the flushing means. 5 The backflushing be around 0.1% - 0.5% of the throughput, for example, with a filter amount in a size range of 1 -. 10m³ Liquor per hour. By deriving the coarse filtrate from the cross-flow filter, a concentration of impurities is prevented, said discharged coarse filtrate can be used skilfully for backwashing. The backwashing device 5 further comprises a supply of purge air to a corresponding valve 25. The air-Grobfiltratgemisch may then via the conduit 26 back into the coarse filter 2a / b are pressed whereupon this is conveyed with the dirt into the drain 27th For this purpose, corresponding 3 / 2wegeventile 13, 14, 11, 12 are provided which can be switched so that in each case a filter is back-washed while the other is in operation.

p0029Before and after the filters 2a, b corresponding pressure sensors can be arranged that the differential pressure before and behind the corresponding coarse filters 2a, b determined, which is compared with a desired value. If the measured differential pressure the predetermined target value, so a backwash process is initiated for a corresponding filter.

p0030The discharge line 6 branches off from the return line annularly guided 4th It would also be possible that these derivative 6 acts directly on the output of the cross-flow filter. Advantageously, the derivative 6 is arranged in a range from the rear end A of the cross-flow filter 3 to the point B, at which a new coarse filtrate from the filters 2a / b of the circle K is fed. The apparatus may further comprise a branch line 8, for discarding a portion of the circulating coarse filtrate. For example, when cleaning the main caustic concentration in District K too high, in addition via the outlet 8 a certain part can be discarded. For this purpose the valve 29 is provided. Before and after the cross-flow filter module can pressure sensors (not shown) can be arranged, which, ie the transmembrane pressure measured, the pressure difference. This differential pressure is compared with a setpoint value. Exceeds the determined differential pressure setpoint, then coarse filtrate which is recycled K, diverted.

p0031In the processing of post-caustic that circulated coarse filtrate can via the branch line 8 also for pretreating, ie directed for example to Vorlaugebad. The quality of the cleaning solution in Vorlaugebad the coarse filtration is sufficient. Moreover, it is advantageous here that the surfactants are not filtered in the coarse filtrate and remain in the liquor. The branch pipe 8 is here to the return line 4, but can also, as described above adjacent to the cross-flow filter.

p0032The inventive method will be explained in more detail in connection with the cleaning of the main liquor a Hauptlaugebads 28 a bottle cleaner 10th First, is pumped via a pump 9 via the line 24. soiled cleaning liquor from the main caustic bath 28 in the device according to the invention first Contaminated cleaning solution happened while the coarse filter 2a / b, the valves being 11/12, 13/14 switched so that the cleaning solution flows through the filter in the direction of arrow to the line 30th The coarse filters 2a / b are disconnected from the purge line 26th The grobfiltrierte cleaning liquor is then pumped via pump 10 in the cross-flow filter. 3 Transverse to the flow direction of the coarse filtrate enters the coarse filtrate through the membrane and is therefore fine filtered. The fine filtrate is the main caustic bath 28 is recycled via the line 7 with the valve open sixteenth The coarse filtrate that is passed through the cross-flow filter 3 out through the return line 3 in the circle at point B where K new coarse filtrate is supplied to the circuit. To prevent the concentration of impurities in the circuit K a certain portion of the coarse filtrate via line 6 of the backwashing device 5, and a washing of the backwashing device 5 is supplied. In this continuously, a specific part to be removed from the circuit K or clocked at specific time intervals a certain amount to be derived coarse filtrate. This dissipated coarse filtrate, which is then stored in the container of the flushing means 5 can then be used advantageously to backwash one of the two coarse filters 2a / b.

p0033The backwash of the coarse filter 2a / b, for example, the valve 13 is switched to that backwash line 26 is connected to the coarse filter 2a, the coarse filter 2a is not otherwise connected to the line 30th Furthermore, the valve 11 is adjusted so that the coarse filter 2a is connected to the drain 27, but not further with the line to the pump 9. The backwash while air is blown into the washing compartment. The air-Grobfiltratgemisch is then forced through the conduit 26 back through the filter 2a and then transported to the dirt down the drain. During the coarse filter 2a backwashed will remain the valves 12/14 in which the filter 2b, the coarse filtration takes over in a position, wherein the cleaning liquor is passed in the arrow direction into the pipe 30th After backwashing valves 11/13 again returned to its working position, so that the coarse filtration and can be done via the filter 2a again. Below can then be backwashed 2b by corresponding switching of the valves 11/12/13/14 in the same way, the coarse filter. As previously described, the backflushing process for a coarse filter 2 can then be initiated if the measured pressure difference exceeds before and after the coarse filter a certain target value. This ensures that the cleaning solution can be continuously processed and the process also during backwashing must not be interrupted. This would also be the concentration of the cleaning solution in the cross-flow filtration circuit K is prevented is also the cross-flow filter not to, so that continuous operation is possible. If the concentration in the circuit K are too large, may additionally via line 8 coarse filtrate from the circulation K are discharged by the valve 29 is opened accordingly. This dissipated coarse filtrate is then discarded.

p0034Advantageously, the concentration can be prevented here without a large feed tank is necessary. Thus, small volumes in the filtration unit can be realized, which leads to a minimized heat radiation. Furthermore, the whole system may be under pressure, resulting in minimized pump powers result. Small filling volumes offer the additional advantage that the availability of the bottle washer is increasing as refilling the bottle washer at the start of the filtration system is not necessary.

p0035In the cleaning of post-caustic, the method as described in connection with the main liquor takes place has been explained. Here too coarse filtrate from the membrane filtration circuit is used for backwashing, as previously explained. In contrast to the previous embodiment, however, when coarse filtrate is necessary, removed via line 8 and not discarded, but fed to a Vorlaugebad 32nd

p0036<figref idrefs="f0005">figure 7</figref> shows the basic diagram of a storage tank CIP system (Cleaning in Process). Such a system 70 has a fresh water tank 71, a stack of water tank 72, a disinfecting liquid tank 73, an acid tank 74 and a washing tank 75th Further, a CIP system can also have a supply of liquor concentrate 76, for acid concentrate 77 and for disinfecting concentrate 78th The detergent concentrates 76, 77, 78 are with the cleaning water in the corresponding Desinfektionsflüssigkeits-, acid, or alkali tanks 73, 74, 75 diluted to the appropriate concentration. Via the line 79, the corresponding cleaning liquid from the tanks 73, 74, 75 the object to be cleaned (with tank cleaning apparatus, pipes, etc.) are supplied and returned via the return line 80 to the corresponding tanks. can via a not shown line 24 then the appropriate cleaning fluid from the tank 73 or 74 or 75 of the in<figref idrefs="f0001">figure 1</figref> shown apparatus are supplied. The fine filtrate can then use the in<figref idrefs="f0001">figure 1</figref> Feinfiltratleitung 7 shown to be fed back to the respective tanks 73, 74 or 75th The in on the drain line 8<figref idrefs="f0001">figure 1</figref> discharged coarse filtrate can be discarded.

p0037It is advantageous that the same flowchart can be used to Hauptlaugen- and Nachlaugenreinigung a bottle cleaner 10 and for CIP systems 70th This brings production advantages with it, because for all applications, the same device can be built, which differs only by the pore size of the membrane of the cross-flow filter. 3 Thus, the cleaning liquid can be purified by a low-cost device. The fact that the energy removed in the membrane filtration circuit coarse filtrate is not completely discarded, but used for backwashing, process media and energy can be saved.