CH672602A5 - - Google Patents

Description

DESCRIPTION The invention relates to a two-stage or multi-stage method for removing impurities from still or carbonated liquids, in particular beverages,

3rd

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

672 602

as it is reproduced in the preamble of claim 1. Furthermore, the invention relates to a device for performing this method, the type of which is given in the preamble of claim 12.

In the known two-stage or multi-stage process for removing impurities from still or carbonated liquids, in particular beverages, filters with properties as disinfection filters have been used in the last process stage, which serves to remove residual impurities, in particular microbiological impurities, but they do Type correspondingly significantly lower flow rate and thus significantly lower throughput than the filter used in the previous process for clarification. In order to enable a continuous process flow, if the known disinfection filters are used to remove residual impurities, in particular microbiological impurities, filtration devices of a much larger size would have to be used in this process stage than in a process stage which serves to pre-clarify the liquid.

However, this would entail considerable investments and increased costs for carrying out the process in terms of filter material, process monitoring, maintenance, etc. In addition, the particularly large-sized filtration devices required in the process step for removing residual impurities, in particular microbiological impurities, would require space, which is often not available.

In contrast, the invention is based on the object, in a two-stage or multi-stage process for removing contaminants from still or carbonated liquids, in particular beverages, a filtration for removing residual contaminants, in particular microbiological contaminants with high flow rate and correspondingly high throughput with the least possible use of filter material and use as simple as possible to be able to carry out filtration devices which are characterized by a small space requirement and with good adaptability to previous process stages which serve to clarify.

This object is achieved by the measures specified in the characterizing part of claim 1.

It is known that precoat filtration processes can be provided with disinfectant properties using appropriate filter aids or filter aid mixtures and while maintaining the limited flow rate of the liquid to be filtered through the precoat layer. It is also known that the constant addition of filter aids to the liquid to be filtered, which is common in precoat filtration processes, can be omitted if the liquid to be filtered does not contain any impurities which block the surface area of the washed-up layer. Assuming this previous knowledge, it is surprising, however, that a precoat filtration process can only be designed to remove residual impurities, especially microbiological impurities, from pre-clarified liquid in such a way that disinfection filtration, even at high flow rates of the pre-clarified liquid, through the washed-up layer and with the least possible use of filter aids can be designed in a simple manner by building up the precoat layer to be formed for the removal of residual impurities, in particular microbiological impurities, while maintaining a flow rate of at least 15 hl m "2h" 'in damped turbulence from filter aids or filter aid mixtures and maintains this washed-up layer in its originally set thickness even during the filtration process. It is also surprising that such a precoat layer can also be regenerated as such in terms of its properties for removing residual impurities, in particular microbiological impurities, and that the filter aid or filter aid mixture used in such precoat layer can also be regenerated and rewashed after the filter cake has been removed.

Furthermore, it has surprisingly been found that filter aids and filter aid mixtures containing kieselguhr are particularly advantageous for forming the washed-on layer to be used in the context of the invention, fiber content of such filter aids or filter aid mixtures being recommended, but layers washed on from kieselguhr are also well suited for the purposes of the invention . If filter aids or filter aid mixtures containing plastic fibers are used, then the dispersion of the filter aid or the filter aid mixture formed to float the layer or layers should be formed in cold or warm water with an amount of filter aid added in the range of 10% by weight of plastic fibers and while maintaining a precoat flow between 50 and 100 hl m "2h" ', preferably at 70 hl m "2h"', washed up. The thickness of the precoat layer or precoat layers to be formed in the context of the invention should be as uniform as possible and should be between 5 and 15 mm, preferably 8 mm. Furthermore, it has surprisingly turned out to be advantageous to use the washed-up layer or layers in a substantially horizontal position for the filtration according to the invention for removing residual impurities, in particular microbiological impurities, from pre-clarified liquid.

Further advantageous measures for the implementation of the method according to the invention and for the regeneration are given in claims 5 to 11.

An inventive device for performing the method is given in claim 12. This device contains, among other parts of the device, a filter press designed for precoat filtration as a filtration device for removing residual impurities, in particular microbiological impurities from the pre-clarified liquid, and for maintaining the filtration operation of this filter press and for preparing and reworking the filtration process, in particular for pre-washing the filter aids and the facilities required for regenerating the washed-up layer or layers and the filter aids or filter aid mixtures removed from the filter press as a filter cake.

A particularly advantageous development and improvement of this device consists in the fact that the trub frames are arranged horizontally in the filter press and have a structure as set out in claim 13.

The subdivision of the trub frames can be provided such that an upper trub frame with the inlet for the liquid to be filtered as well as the distribution chamber and trub frame and a diverting plate separate from the upper trub frame are provided, which has the carrier element for the precoat layer to be built up and the filtrate outlet, as is the case here is specified in claim 18. Between such an upper trub frame and the lower baffle plate can then be arranged optionally and in the desired number of insert trub frames, as specified in claim 19.

4th

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

In general, advantageous developments and improvements of the device according to the invention and its parts are specified in claims 13 to 27.

Particular advantages of both the method according to the invention and the device according to the invention are:

1) A high specific area performance of the washed-up layer or layers can be guaranteed with full guarantee of the filtration task. As a result, the filtration stage for removing residual impurities, in particular microbiological impurities, can be easily adapted to previous clarification stages.

2) Due to the high specific area performance of the washed-up layer, small dimensions of the filtration device or the filter press designed for precoat filtration are possible, as a result of which the investment costs can be kept low.

3) The regeneration option results in a long service life of the filter aid or filter aid mixture.

4) The filtration costs can be kept low. For example, the filtration costs for removing microbiological contaminants in the process according to the invention are only about 10% of the filtration costs in previous sterilizing filtration processes.

5) The regeneration to be carried out within the scope of the invention, both of the washed-on layer and of the filter aid or filter aid mixture outside the filter device, can be carried out particularly easily.

6) The method according to the invention is characterized by particularly low consumption values of water and energy.

7) The device according to the invention enables the used filter aids to be discharged particularly easily from the filter device.

8) The device according to the invention can be easily automated and is characterized by a low need for operating and maintenance personnel.

9) Due to the reduction in the consumption of filter aids made possible by the invention, there is also a significant reduction in the environmental impact.

10) The device according to the invention is characterized by a short-circuit-proof system.

11) The device according to the invention contains only a few moving parts and is therefore characterized by particularly low wear.

12) The device according to the invention is particularly easy to maintain. The scope of maintenance required is low; Maintenance activities are easy to carry out.

13) The filter press for precoat filtration used in the device according to the invention is particularly easy to use, especially when changing layers, since the few elements can be separated automatically when the filter press is opened and can be removed individually.

14) The operation of the filter press is simple,

not least thanks to the easy-to-monitor hydraulic pressure known from filter presses.

15) When the washed layer or layers are arranged horizontally, high insensitivity to pressure surges is achieved during the filtering process.

An embodiment of the invention is explained below with reference to the drawing. Show it:

Figure 1 is a schematic diagram for the inventive method.

2 shows the diagram for an example of the formation of the preliminary clarification stage;

672 602

3 shows a filter press that can be used as a filtering device in the process step for removing residual impurities, in particular microbiological impurities, from the pre-clarified liquid, schematically in a top view;

4 shows the filter press schematically in vertical section 4-4 of FIG. 3;

5 shows the filter press in vertical section 5-5 of FIG. 3;

Fig. 6 shows the detail 6 of Figure 5 on an enlarged scale and

Fig. 7 shows a modified precoat and regeneration tank.

As shown schematically in FIG. 1, a device for the two- or multi-stage removal of impurities from still or carbonated liquids, e.g. As beer, devices 11 for pre-clarifying the beer and subsequent filtering devices 12 for removing residual impurities, in particular microbiological impurities, such as yeasts, bacteria etc., from the pre-clarified beer. These filtering devices 12 contain a filter press 13 designed for precoat filtration with horizontally arranged trub frames 14 which are held between a fixed upper cover 15 and a vertically movable lower cover 16. To press the trub frame 14 between the two covers 15 and 16, a hydraulic pressing device 17 acting from below is provided, the upper cover 15 and a frame 100 receiving the pressing device 17 and being supported on the level being connected to one another by means of two parallel bars 101, 102 .

As shown in FIGS. 4 and 5, the subframes 14 of the filter press 13 indicated in FIG. 1 are made as follows:

An upper trub frame 14a is arranged below the upper cover 15 and rests with its cover wall 24a on the underside of the upper cover 15. In the top wall 24a of the upper trubframe 14a there is an inlet 23 for the liquid to be filtered. A circumferential wall 24d extends downward from the top wall 24a and surrounds a horizontally arranged trub space 25 and a horizontally arranged distribution chamber 27 and also a horizontally arranged baffle plate 26 inserted between the plenum chamber 27 and the trub space 25, between the peripheral wall 24d and the An annular gap 28 is formed on the circumferential edge of the guide plate 26. The peripheral wall 24d has a lower annular end face 24f.

On the top of the lower cover 16, a baffle plate 14c is placed, which has a bottom wall 24c and a raised peripheral frame 24g. This raised circumferential frame 24g accommodates collection and discharge devices for the filtrate, the peripheral frame 24g having an upper end face 24h.

Furthermore, according to FIG. 4 and FIG. 5, insert trub frames 14b are provided, which are to be inserted between the upper trub frame 14a and the deflection plate 14c, as desired and in the desired number. These insert trub frames 14b differ from the upper trub frame 14a in that they have a somewhat greater height on the circumferential wall 24d and instead of the top wall 24a in the upper part, which is recessed with respect to the upper end wall 24i and which carries the collecting and discharge devices for the filtrate Intermediate floor wall 24b are provided. An inlet 23 for the liquid to be filtered and, laterally offset therefrom, a filtrate outlet 33 are further provided in this intermediate bottom wall 24b.

5

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

672 602

6

If only one trub frame 14 is to be used, an upper trub frame 14a and a deflection plate 14c are inserted into the filter press 13 in such a way that the upper end face 24h of the raised peripheral frame 24g and the lower end face 24f on the peripheral wall 24d of the upper trub frame 14a face each other. If it is desired to achieve a larger effective filter area, a selected number of insert trub frames 14b can be applied in a layered manner between the upper trub frame 14a and the deflection plate 14c, as is shown in FIGS. 4 and 5 using the example of two such insert trub frames 14b .

The management of the pre-fermented beer and the finished filtrate in the filter press 13 is as follows:

As FIG. 4 shows, the inlet 19 attached to the lower lid 16 leads to an inlet channel 21 for the pre-clarified beer formed in the eyes 20 of the discharge plate 14c and the trub frame 14a and 14b. In the ceiling wall 24a of the upper trub frame 14a and in the intermediate floor wall 24b of the insert trub frames 14b, insertion channels 22 are formed, which lead from the feed channel 21 guided through the eyes 20 to the downwardly directed inlet 23 formed in the middle above the distributor chamber 27. From this inlet 23, the pre-clarified beer enters the distribution chamber 27 of the upper trub frame 14a and the insert trub frame 14b in order to reach the trub space 25 with damped turbulence through the passage slot 28 formed as an annular gap between the guide plate 26 and the peripheral wall 24d. A precoat 29 is formed on a carrier element 30 at the bottom of the respective turbidity chamber 25, which can be, for example, a prefabricated plate-shaped filter layer, a filter cloth or the like. The respective carrier element 30 is tightly clamped with its peripheral edge region, namely the carrier element 30 arranged between the deflection plate 14c and the insertion truss frame 14b arranged above it is clamped between the lower end face 24f and the upper end face 24h, that between the upper trub frame 14a and the inserting trusses 14b arranged underneath clamped support element 30 between lower end surface 24f and upper end surface 24i and clamped support element 30 arranged between inserting trub frame 14b between lower end surface 24f and upper end surface 24i. These annular end faces 24f, 24h and 24i are accordingly designed as clamping surfaces or pressing surfaces. In this way, the carrier element 30 also forms the edge seal on the associated bottom circumference of the respective trub space 25.

The carrier element 30 rests in the region of the bottom surface of the working space 25 on a support element 31, for example a perforated plate, which in turn is underlaid with a porous base 32, for example a wire mesh, for liquid removal. This pad 32 lies on the top of the bottom wall 24c of the baffle plate 14c or on the top of the intermediate bottom wall 24b of each insertion truss frame 14b. The intermediate floor wall 24b of each insert trub frame 14b has a filtrate outlet 33 in the central region, but laterally offset from the inlet 23, which opens via a filtrate outlet channel 34 into the filtrate discharge channel 35, which in the lateral eyes 36 of the trub frames 14a and 14b and the discharge plate 14c is formed (compare Figures 3 and 5). From this filtrate discharge channel 35 of the eyes 36, a filtrate outlet 37 in the upper fixed cover 15 of the filter press 13 leads via a lockable valve 38 to a filtrate discharge line, not shown.

The filtrate outlet 33a, which is laterally assigned to the discharge plate 14c, also opens into the filtrate discharge channel 35. However, this can also be formed in the respective insert trub frame 14b instead of the filtrate outlet 33 and the filtrate outlet channel 34. It is also possible to assign the filtrate outlet 33 and the filtrate outlet channel 34 to the discharge plate 14c if the bottom wall 24c is designed in accordance with the intermediate bottom wall 24b.

The filter press 13 is also equipped with rinsing devices for removing the filter cake or the washed-on layers 29. For this purpose, a flushing agent inlet 39 and a flushing agent outlet 40 are provided in the lower cover 16 of the filter press 13, and according to the illustration in FIG. 5 the flushing agent outlet can also be fitted in the upper cover 15. Shut-off valves 44 and 42 are assigned to the detergent inlet 39 and the detergent outlet 40 outside the filter press 13 and inside the filter press 13 from eyes 43 of the upper trub frame 14a, the insert trub frame 14b and the diverter plate 14c. In the peripheral wall 24d of the upper tube frame 14a and the insert trub frame 14b, a rinsing bore 45 extends from each of these rinsing channels 44 into the bottom region of each trub space 25 at a distance above the respective carrier element 30 which is essentially the maximum thickness of a layer 29 to be washed up corresponds. Furthermore, the filter press 13 is provided with venting devices which have a vertical venting channel 46 which is guided through lateral eyes 47 to the trub frame 14a and 14b and the discharge plate 14c. This vent channel 46 is connected in each trub frame 14a, 14b through a vent hole 48 to the upper part of the distribution chamber 27 and leads to a vent outlet 49 in the upper cover 15 with a vent valve 50.

Finally, in the area of the lower movable cover 16 of the filter press 13 there is also an emptying outlet 51 with a shut-off valve 52 connected to the flushing agent channel 39, to which the filtrate discharge channel 35 can also be connected.

As FIG. 1 shows, the filtering devices 12 for removing residual impurities or microbiological impurities from the pre-clarified liquid contain a line 53 for the pre-clarified beer leading from the pre-clarification devices 11 to the inlet shut-off valve 18 of the filter press 13. In this line 53, a static mixer 54 is inserted, which - as explained later - becomes effective when the layer 29 or layers in the filter press 13 are suspended.

The devices 12 for removing residual impurities or microbiological impurities from the beer also contain a precoat and regeneration container 60 in which a stirrer 61 driven by a motor 62 is attached. This precoat and regeneration tank 60 has a bottom connection 63 with shut-off valve 64, furthermore an outlet 65 arranged in the bottom area and a second connection 66 with shut-off valve 67 arranged in the lower part of the tank. Finally, as shown in FIG. 1, the precoat and regeneration container 60 can be provided on its upper part with an overflow device 68 with a retaining fabric 69 which retains a filter aid. This retaining fabric 69 is juxtaposed in the interior of the container with a nozzle 70 to be charged with precoat liquid in order to remove retained filter aid particles adhering to the retaining fabric 59.

Furthermore, the devices 12 for removing residual impurities or microbiological impurities contain a lye container 71 with a motor-driven stirrer 72. This lye container 71 has a bottom connection 73 with a shut-off valve 74. Finally, in the

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

An acid container 75 with a motor-driven agitator 76 is provided for devices for removing residual impurities or microbiological impurities. This acid container 75 also has a bottom connection 77 with a shut-off valve 78.

For the operation of the rinsing devices of the filter press 13, two rinsing agent lines are provided, of which the one rinsing agent line 55 from the bottom-side shut-off valve 78 of the acid container 75, the bottom-side shut-off valve 74 of the alkali tank 71 and the bottom-side shut-off valve 64 of the precoat and regeneration tank 60 via the shut-off valve 41 to the detergent connection 39 of the filter press 13. An additional shut-off valve 79 is inserted between the shut-off valve 64 on the bottom of the precoat and regeneration tank 60 and the shut-off valve 41 on the filter press 13, while between the shut-off valve 64 on the bottom of the precoat and regeneration tank 60 and the shut-off valves 74 and 78 on the bottom of the lye tank 71 and the acid container 75, a discharge pump 80 and a further shut-off valve 81 are connected, the shut-off valves 79 and 81 and the discharge pump 80 being bridged by a bypass which can be closed by a shut-off valve 82. A regenerant line 57, in which a regenerant pump 84 is arranged, is also connected to the flushing agent line 55. The outlet of this regeneration agent pump 84 leads to the shut-off valve 67 of the second connection 66 at the bottom area of the precoat and regeneration container 60, further to the spray nozzle 70 and via a shut-off valve 85 to the liquid supply line 53 extending from the pre-clarification devices 11 to the filter press 13. The second flushing agent line 56 leads from the shut-off valve 42 at the second flushing agent connection 40 of the filter press 13 via a shut-off valve 83 to the connection area of the shut-off valve 64 of the first flushing agent line 55 lying between the shut-off valve 79 and the discharge pump 80 and via a further shut-off valve 86 to that part of the first flushing agent line 55, to which the shut-off valves 74 and 78 of the alkali container 71 and the acid container 75 are connected. Finally, a shut-off valve 87 leading to a liquid drain is also provided on the detergent line 55. Finally, as an essential part, a precoat line 58 is provided in the filtering devices 12 for removing residual impurities or microbiological impurities, which leads from the bottom connection 65 of the precoat and regeneration container 60 via the precoat pump 88 and a shut-off valve 89 to the liquid supply line 53, in such a way that that the static mixer 54 lies between the connection of the precoat line 58 and the inlet shut-off valve 18 of the filter press 13 in the liquid supply line 53.

The main feed pump 90 is attached in front of the entire device, namely in front of the entrance of the devices 11 for pre-clarification, which controls the entire liquid flow both through the pre-clarification devices 11 and through the filtering devices 12 for removing residual impurities or microbiological impurities.

The clarification devices 11 can be of various types. For example, a layer filter with layers for preliminary clarification can be provided. Boiler filters such as centrifugal cleaning filters, candle filters, gap filters etc. can also be used. The clarification devices 11 can also have one or more centrifuges as clarification devices. Finally, one of the filter press 13 can be the same or similar filter press for precoat filtration with a horizontal layer arrangement or a diatomaceous earth filter with a vertical one

672 602

Layer arrangement may be provided. This latter case is indicated in FIG. 2 as an example. The main feed line 91 runs from the main feed pump 90 to the inlet of the diatomaceous earth floating filter 92. A known diatomaceous earth meter 93 with a metering pump 94 is connected to the main feed line 91. The liquid supply line 53 runs from the diatomaceous earth filter 92 in the form of a filter press with a vertical layer arrangement to the filtering device 12 intended for removing residual impurities or microbiological impurities. In the conventional manner, a shut-off valve 95 and 96 are located at the inlet of the diatomaceous earth filter 92 and at its outlet appropriate.

The clarification devices 11 can naturally also be designed in two or more stages.

With the device described above, the two-stage or multi-stage process for removing impurities from beer or other still or carbonated liquids can be carried out in the following manner:

To prepare the device, the layer 29 or layers must first be built up in the diatomaceous earth filter 92, if one is used for preliminary clarification, and in the filter press 13. In the filter press 13, the layer 29 or layers is built up in such a way that a dispersion is formed in the precoat and regeneration tank 60 from water or pre-clarified beer and the amount of filter aid or filter aid mixture to be measured, which is carried out via the precoat pump 88 Liquid supply line 53 and the static mixer 54 arranged therein (when the shut-off valves 41, 42, 50, 52, 64, 67, 85, 96) are guided into the supply and distribution devices 18 to 28 of the filter press 13. The precoat pump 88 is to be controlled in such a way that a flow rate of at least 15 h nr2h "'is maintained. If the filter aid or filter aid mixture contains plastic fibers, the flow rate is between 50 and 100 hl per square meter and hour, preferably at 70 hl per square meter per hour The liquid flowing off when the layer 29 or layers are washed away is discharged via the collection and discharge devices 32 to 41 also used in the filtering process and can be collected at the filtrate outlet 37 of the filter press 13 and, if necessary, retained for reuse as a washing-up liquid or for rewashing and, after the precoating process has been completed, reintroduced into the precoat and regeneration container 60.

After the precoating process has taken place, when the precoated layer 29 or precoated layers each have a substantially uniform thickness between 5 and 15 mm, preferably essentially 8 mm, the precoat layers 29 are rinsed in a conventional manner with warm or cold water and then in Flow direction sterilized at about 85 ~ C for 20 minutes. After sterilization of the washed layer 29 or washed layers, the filtering process is carried out in which the liquid to be filtered, pre-clarified in the diatomaceous earth filter 92, e.g. B. beer, is continuously pumped by means of the main feed pump 90 via the liquid supply line 53 and the inlet 19 into the filter press 13. When filtering, it is advisable to monitor the pressure drop across the washed layer 29 on the filter press 13 while maintaining a constant flow. If the pressure drop rises above a defined limit, the filtering process is interrupted and regeneration treatment is carried out. For this purpose, a regeneration treatment of the washed-up layer 29 or ange7 is recommended

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

672 602

washed layers in the filter press 13. For this purpose, fifty-degree, 0.3% sodium hydroxide solution contained in the suds container 71 is used, which for this regeneration process has previously been heated to 60 ° C. in the suds container 71 by means of heating devices (not shown). This sodium hydroxide solution is closed when it is closed Shut-off valves 67, 81, 86, 87 and 78, 89 are introduced via the open shut-off valve 74 to the regeneration agent pump 84 and from there, with the shut-off valve 85 open and the shut-off valve 96 closed, into the liquid supply line 53 which is also provided for the filtering process via the supply and distribution devices 18 to 28 provided for the pre-clarified liquid during the filtration process to the washed-up layer 29 or the washed-up layers and, with the corresponding setting of the regenerating pump 84, with a flow rate of 16 hl m "2h_1 at least 10 minutes, preferably However, it is led through the washed layer or layers for 30 to 45 minutes. The sodium hydroxide solution is discharged via the collection and discharge devices 32 to 41 provided for the filtrate during the filtration process. The sodium hydroxide solution is collected at the filtrate outlet 37 of the filter press 13 and returned to the solution container 71 (via a line, not shown). After this regeneration process has been carried out, rinsing with water, preferably hot water, of approximately 60 ° C. is carried out, which may be contained in the precoat and regeneration tank 60, for example, as a precoat. This rinsing process is preferably carried out via the precoat pump 88 and the feed and distribution devices 18 to 28 and the collection and discharge devices 32 to 34 of the filter press 13, the water in turn from the filtrate outlet 37 of the filter press 13 to the precoat and regeneration tank 60 in the circuit is due. Finally, neutralization of the washed-up layer 29 or washed-up layers with strongly dilute nitric acid (0.1% to 0.3% nitric acid) can be carried out at about 10 ° C. for 15 minutes. This nitric acid is circulated from the acid container 75 via the shut-off valve 78, the regenerant pump 84 and the shut-off valve 85 to the liquid supply line 53 and also via the feed and distribution devices 18 to 28 and the collection and discharge devices 32 to 41 of the filter press 13. After this regeneration process has been completed, the washed-on layer 29 or washed-on layers and the entire filter press 13 must be sterilized again, as has already been explained above. This regeneration process can be repeated several times at predetermined time intervals or with the monitoring of the pressure drop mentioned above. After repeated repetition of this regeneration process of the washed-up layer 29 or washed-up layers maintained in the filter press 13 or if, when monitoring the pressure drop, a very rapid and strong pressure drop across the washed-up layer 29 or

Layers is determined during the filtering process, it is advisable to remove the precoat 29 or layers with the impurities embedded therein, that is to say the filter cake consisting of precoat 29 or precoat, from the filter press 13. For this purpose, the filter cake is rinsed out of the filter press 13 via the rinsing agent lines 55 and 56 and the rinsing devices 39 and 45 formed in the filter press and transferred together with the rinsing liquid, for example water, into the precoat and regeneration container 60. The filter cake can also be rinsed out of the filter press 13 by means of the 40%, 0.3% sodium hydroxide solution stored in the tub 71. In the precoat and regeneration tank 60, regeneration then takes place with intensive stirring and intermediate washing out with cold or warm water and neutralization with 0.1% to 0.3% nitric acid at approx. 10 ° C. for approx. 15 minutes. The regeneration time can be 16 hours. After regeneration has taken place, the dispersion contained in the precoat and regeneration container 60 is metered and prepared for the precoating process, if necessary by filling with filter aid or filter aid mixture. The precoating process is then carried out again in the same way as explained above.

At the beginning of the respective filtration or precoat process, but also when the filter press 13 is emptied, the vent valve 50 is opened long enough for the filtration or precoat process to take place when the respective turbidity chamber 25 or distributor chamber 27 is completely filled and the filter press 13 is completely emptied during the emptying process.

As shown in FIG. 7, the precoat and regeneration container 60 can have a pump-over device 83 instead of the agitator 61 driven by motor 62 and the overflow device 68 having a retaining fabric 69 and a spray nozzle 70. This has a pumping line 97, which runs from the bottom area of the precoat and regeneration container 60 to its upper part, into which a pump 98 and an overflow vessel 99 are inserted above the pump 98 in the direction of flow. From this, an overflow line 103 with an overflow valve 104 interposed therein leads to the drain. Provided within the overflow vessel 99 is a retention fabric 69 which keeps the mouth of the overflow line 103 free and which is kept free from the dispersion in the manner of a suspension by the pump flowing in the pumping line 97 and sucked in by the pump 98 from the lower part of the precoat and regeneration container 60 is, so that when the overflow valve 104 is opened, excess regeneration agent can freely enter the overflow line 103 via the mouth on the vessel side and, after passing through it, can flow into the drain.

Suitable filter aids are the usual diatomaceous earths, perlites, celluloses, plastic fibers used for precoat filtration, from which the filter aid mixtures are also put together, the filter aids or filter aid mixtures should have properties such that the precoated layer 29 or Layers with high filtration capacity retain germs that are harmful to the drink, such as yeasts, bacteria, fungi, spores, etc. and can be regenerated.

8th

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

7 sheets of drawings

Claims (27)

672 602 PATENT CLAIMS 1. Two- or multi-stage process for removing impurities from still or carbonated liquids, in which a filtration is carried out as a process step for removing residual impurities from the liquid pre-clarified in the first stage or a previous stage, characterized in that the pre-clarified liquid is filtered in a filter press through one or more pre-washable layers of predetermined thickness formed therein from a filter aid or a mixture of filter aids without the prior addition of filter aids, this layer or layers prior to filtering the pre-clarified liquid while maintaining a flow rate of at least 15 hl m ~ 2h "'is washed up in dampened turbulence in the filter press. 2. The method according to claim 1, characterized in that when filtering the pre-clarified liquid with one or more pre-washed layers which contain plastic fibers in the filter aid, the floating of the layer or layers with a dispersion of the filter aid or the filter aid in cold or warm water with the addition of filter aids in the range of 10% by weight while maintaining a precoat flow between 50 and 100 hl m "2h_1, preferably at 70 hl m" 2h_1. 3. The method according to claim 1 or 2, characterized in that the washed-up layer or layers are or are formed in a uniform thickness of 5 to 15 mm, preferably of essentially 8 mm. 4. The method according to any one of claims 1 to 3, characterized in that the pre-clarified liquid is filtered through one or more washed layers, which are arranged essentially in a horizontal position. 5 5. The method according to any one of claims 1 to 4, characterized in that the maintenance of constant flow is monitored during filtering the pressure drop across the washed-up layer or layers and that when the pressure drop rises above a defined limit value, a regeneration treatment of the washed-up water retained in the filter press Layer or layers is made. 6. The method according to claim 5, characterized in that the regeneration of the washed layer or layers maintained in the filter press, a treatment with sodium hydroxide solution, for example 50%, 0.3% sodium hydroxide solution over 30 to 45 minutes at 60 ° C and rinsing with warm water, for example 60 ° C. over 15 minutes, and optionally an acid treatment, for example with 0.1% to 0.3% nitric acid. 7. The method according to any one of claims 1 to 4, characterized in that when filtering, the throughput through the washed layer or layers, for example by means of the pressure drop across the layer or layers while maintaining a constant flow, is monitored and that when the throughput drops below a specified limit value and / or if the drop occurs after the filtration time below a specified limit value, the washed-up layer or layers are removed from the filter press, the filter aid or the mixture of filter aids is regenerated outside the filter press and from the regenerated and, if necessary, by The addition of fresh filter aids, sharpened filter aids or a mixture of filter aids, a new layer or layers are washed up. 8. The method according to claim 7, characterized in that the regeneration of the filter aid or filter aid mixture by dispersing the filter cake removed from the filter press in 50%, 0.3% sodium hydroxide solution and two or more lye treatment of the dispersed filter aid or Filter aid mixture is carried out with intensive stirring and intermediate washing out with cold or warm water and neutralization with 0.1% to 0.3% nitric acid at approx. 10 C for approx. 15 minutes. 9. The method according to any one of claims 1 to 8, characterized by the combination of the filtration of the pre-clarified liquid by means of one or more pre-clarified layers with a pre-clarification of the liquid by filtration by means of one or more pre-clarified layers of filter aid or filter aid mixture, the pre-clarification in a closed system and is carried out with constant addition of filter aids to the liquid to be clarified. 10th 10. The method according to any one of claims 1 to 8, characterized by the combination of the filtration of the pre-clarified liquid by means of one or more precoated layers with a preliminary clarification of the liquid by centrifugation. 11. The method according to any one of claims 1 to 8, characterized by the combination of the filtration of the pre-clarified liquid by means of one or more pre-washed layers with a pre-clarification of the liquid by means of prefabricated filter layers or filter candles to be selected in accordance with the respective case. 12. An apparatus for performing the method according to any one of claims 1 to 11, the means for pre-clarifying a still or carbonated liquid and subsequent filtering means for removing residual impurities from the pre-clarified liquid, characterized in that the filtering means (12) for removal residual impurities from the pre-clarified liquid, a filter press (13) designed for precoat filtration with a trub frame (14) for pre-washing one or more layers of filter aids, and with feed and distribution devices (18-28) for the pre-clarified liquid, collection and discharge devices ( 32 to 41) for the filtrate, venting devices (46 to 50) and rinsing devices for emptying the washed-up layer (29) or layers and precoat devices connectable to the filter press (13) with metering device for filter aids or filter aid mixture and discharge devices for the precoat liquid and regeneration devices connectable to the filter press (13) for the washed-on layer (29) remaining in the filter press (13) or layers and regeneration devices for the filter aids or filter aids removed from the filter press (13) in the form of filter cakes. Contain filter aid mixtures. 13. The apparatus according to claim 12, characterized in that the filter press (13) has one or more horizontally arranged trub frames (14) for the floating of one or more layers (29) of filter aid or filter aid mixture, which between horizontal, by means of a vertically acting pressing device (17) against each other movable covers (15, 16) are held, in each trub frame (14) a trub chamber (25), a distribution chamber (27) and an optionally additionally supported support element (30) for the layer to be washed up ( 29) are all arranged horizontally, with arrangement of the supply and distribution devices (18 to 28) for the liquid to be filtered to the distribution chamber (27) above the turbid chamber (25) and arrangement of the collection and discharge devices (32 to 41) for the Filtrate underneath the carrier element (30) for the wash-up 2 14. The apparatus according to claim 13, characterized in that in the filter press, the inlet (23) for the liquid to be filtered opens approximately centrally on the top of the chamber in the distribution chamber (27) and on a baffle 15. The apparatus of claim 13 or 14, characterized in that in the filter press, the carrier element (30) is formed by a prefabricated plate-shaped filter layer, which at the same time forms the edge seal on the bottom circumference of the trub space (25). 15 16. Device according to one of claims 13 to 15, characterized in that in the filter press, the support element (31) with a porous support (32), for example a fabric, and the filter outlet (33) is arranged below this support (32). 17. Device according to one of claims 13 to 16, characterized in that in the filter press, the trub frame (14) are each provided with two lateral, vertical rinsing channel pieces (44) and from each of these rinsing channel pieces (44) a rinsing hole (45) to the bottom area of the respective trub space (25), which opens at a distance above the respective support element (30) into the trub space (25), which corresponds at least to the maximum thickness of a layer (29) to be washed up. 18. Device according to one of claims 13 to 17, characterized in that in the filter press an upper trub frame (14a) with the inlet (23) for the liquid to be filtered contained ceiling wall (24a), one of the distribution chamber (27) and the trub space (25) surrounding peripheral wall (24d) and one between the distribution chamber (27) and the trub space (25) inserted baffle plate (26), and a lower baffle plate (14c) are provided, which has a collecting and discharge device for the filtrate bottom wall (24c) with an elevated peripheral frame (24g), the lower end face (24f) on the circumferential wall (24d) of the upper trub frame (14a) and the upper end face (24h) of the raised peripheral frame (24g) on the deflector plate (14c) as opposed, sealing the support element (30) between them receiving clamping surfaces are formed. 19. The apparatus according to claim 18, characterized by one or more insertable trub frame (14 b) which can be used optionally in the filter press between the upper trub frame (14 a) and the lower diverting plate (14 c) and which in the upper part has an opposite end rim (24 i) ) recessed, the collection and discharge devices (32 to 35) for the filtrate and the inlet (23) for the liquid to be filtered intermediate floor wall (24b) is provided, and below this the distributor chamber (27), the baffle (26) and the trub space (25), the upper end face (24i) of the insert trub frame (14b) with the lower end face (24f) of the upper trub frame (14a) or the lower end face (24f) of an insert arranged above it Trubframes (14b) and the lower end face (24f) of the insert trub frame (14b) with the upper end face (24i) of an insert trub frame (14b) arranged below it or the upper end face (24h) of the discharge plate (1 4c) as clamping and sealing 672 602 surfaces for the intermediate regions of the carrier elements (30) are formed. 20. Device according to one of claims 13 to 19, characterized in that the filter press (13) has a firmly attached upper lid (15) and a vertically displaceable lower lid (16), the upper lid (15) the inlet and Outputs and connections for filtrate discharge lines, supply lines for the liquid to be filtered, supply lines and discharge lines for rinsing liquid as well as ventilation devices, etc., while the lower cover (16), which may also be provided with inputs and outputs as well as supply and discharge devices, also carries the pressing device (17) is connected. 20th 21. Device according to one of claims 12 to 20, characterized in that the precoat and regeneration devices are combined and a mixing and regeneration tank (60), a tub (71) and an acid tank (75), and a precoat pump (88) , Dosing devices, a discharge pump (80) and a replenishing agent pump (84), these containers (60, 71, 75), pumps (88, 80, 84) and dosing devices by means of valves in the desired process, such as "precoating", " Regeneration in the filter press »and« Regeneration in the mixing and regeneration tank »can be connected to each other and to the filter press (13) in a corresponding manner. 22. The apparatus according to claim 21, characterized in that the mixing and regeneration container (60) are equipped with an overflow (68) covered with a retaining fabric (69) and with a spray nozzle (70) directed towards the retaining fabric (69). 23. The device according to claim 21 or 22, characterized in that the mixing and regeneration container (60) is at the same time designed as a metering and measuring container for the dispersion of filter aid and precoat liquid used for precoating. 24. The device according to claim 21 or 22, characterized in that the precoat pump (88) together with a shut-off and regulating valve used for the pre-clarified liquid together with a feed line (53) leading to the filter press (13) for the pre-clarified liquid (89) are designed as the metering devices. 25. Device according to one of claims 12 to 24, characterized in that a static mixer (54) is used in the feed line (53) leading to the filter press (13) for the pre-clarified liquid in the flow direction behind the metering devices for filter aids or filter aid mixture. 25th 30th 35 40 45 50 55 60 65 de layer (29), and the trub frame (14) also has lateral flushing devices (43 to 45) opening laterally in the trub space (25) for removing the washed-on layer (29). 26. Device according to one of claims 12 to 25, characterized in that the filter press (13) with its inlet (19) for the pre-clarified liquid to the outlet for the pre-clarified liquid of the pre-clarifying devices (11) and the filter press (13) common main feed pump (90) is arranged in front of the inlet of the primary clarifiers (11). (26) which, apart from a passage slot (28) extending around the circumference, separates the distributor chamber (27) and the working space (25) from one another, while the carrier element (30) for the washed-on layer (29) on the floor of the horizontal turbidity chamber (25) is arranged on a support element (31), for example a perforated plate. 27. The device according to any one of claims 12 to 20, characterized in that the pre-clarification devices (11) have a filter press (13) into which filter plates (30) or trub frame (14) can be used individually or one above the other in a horizontal position.