DE2332202A1 - METHOD AND DEVICE FOR CONTROLLING THE PRE-TRAINING AND POST-TRAINING IN DIESEL GURANIC FLAT FILTERS - Google Patents

Description

Seitz- ¥ erke G.M.b.H., 6550 Bad Kreuznach P 2384 / G 2385 (Pati Rf / Bo - June 22, 1973)

Method and device for controlling the pre-run and post-run in Kieaelgur precoat filters

The invention relates to a method for controlling the pre-run and post-run in kieselguhr precoat filters electrical conductivity measurement of the liquid in the filter outlet as well as a device for implementation of the procedure.

In the case of liquid filtration, for example of beer, the kieselguhr deposit is deposited on the filter elements the water remaining in the filter through the subsequent beer in a so-called forerun Phase squeezed out of the filter Conversely, at the end of the filtration, what is still in the filter is removed Beer through added water and describes this phase as the after-run. In both cases the beer-water mixture is used up to a certain content of water still in the beer storage tank, the mixture that then arises up to a further certain water content fed to a tank provided for this purpose. The rest of the mixture with a relatively high water content is eventually led into the drain.

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Ul ty Mt

To determine the desired liquid concentration and thus to determine the points in time for the automatic switching of the liquid from the drain to the supply tank and then to the storage tank and vice versa, controls based on various measuring methods are common. It is known from DL-PS 69 567 to use an electrode placed in the filter outlet to determine the switching points at the beginning or at the end of the filtration by measuring the electrical conductivity of the discharged liquid and to use these points to control the direction of transport of the liquid.

In such controls, which work on the principle of fluid conductivity, the determination is the correct switching points are not always guaranteed. This is due to the fluctuating conductivity of the water used as pre- and post-flow, which, in contrast to beer, its conductivity depending on the type of origin. especially in summer, changes very strongly, sometimes even by leaps and bounds. The object of the invention is therefore for the liquid upstream and downstream of kieselguhr precoat filters to create a control in which the related to the concentration of the filter material-water mixture Changeover points unaffected by the variable electrical conductivity of the as pre-run and post-run

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used Vassers remain constant within a permissible error limit. Starting from the known liquid sleit ability sessung by means of an in filter outlet arranged electrode to determine the point of failure for the liquid transport direction, the object is achieved according to the invention in that one with a Measuring electrode in the water supply line leading to the filter the water conductivity value is constantly recorded and, in the event of changes in conductivity, in the same or any ratio the changeover points for the conductivity value determined changed for the filter material-water mixture. Therefore changes that of the filter for the reasons mentioned above supplied water its conductivity, the proposed procedure ensures a shift in the Urasehaltpunkts for changing the transport direction of the Filter material-water mixture in adaptation to the respective measured conductivity value · For this adaptation to the Each measured conductivity value changes the changeover points, their setting for advance and Follow-up takes place separately, expediently as a percentage.

According to the further invention, the device preferred for carrying out the method is characterized by a control unit, which expediently consists of a computer that determines the ratio of the shifting of the switching points when predetermined water conductivity values are changed, a switching device for initiating the pre-run or post-run and effective connection of the

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changeover points determined for pre-carriage and post-carriage with simultaneous visual display of the respective circuit status, an electropneumatic control device to convert the electrical to pneumatic control signals *

The procedure and device are shown in an example for liquid filtration with a kieselguhr precoat filter shown in the block diagram of the drawing described below:

On a kieselguhr precoat filter 10 for beer filtration, one inlet line and one outlet line each designated by 11 and 12 are connected. The inlet line 11 has a waterway shut-off device 13 · A ^{beer line 15 is connected to its connector 1} Ik and a water line 17 is connected to the connector 16 · Xn the line 17 protrudes an electrode 18 measuring the water conductivity. The outlet line 12 rises into the lines 19 » 20, 21. The line section 19 stands over a shut-off device 22 with a storage tank 23 for beer, the line section 20 over a shut-off device 2k with a supply tank 25 for a beer-water mixture with a predetermined water content and the line section 21 over a shut-off device 26 with a 36 designated drain in connection. The shut-off elements 22, 2k , 26 are connected to a control device 30 with associated lines 27, 28, 29. Connected to control unit 30 via line 3I

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also the measuring electrode 18 and the shut-off element 13, the line of which is denoted by 32. An electrode 33 projecting into the discharge line 12 is also connected to the control unit 30 "with the line Jh. It is also provided for measuring the liquid conductivity. The control unit 3 ° has a switch 35 with which the valve 13 can be switched in position 1 in the flow direction for the flow direction and in position 2 in the flow direction for the after-flow. The shut-off devices 13 »22, 2k, 26 are expediently pneumatically operated and remotely controllable versions.

The control unit 30 consists essentially of a computer that, when predetermined water conductivity values change the ratio of the shift of the switching points is determined, furthermore from a switching device for Initiation of the pre-run or post-run and activation of the switchover points determined for the pre-run or post-run with simultaneous visual display of the respective circuit status, an electropneumatic Control device for converting electrical to pneumatic control signals.

This results in the following process sequence t

After the precoat has been carried out and the switch 35 is kept in position 2 (after-run), the shut-off element is 13 open in the direction of line 11 and to

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Line 15 blocked. The shut-off element 26 is also open to the drain 36. The other organs 22 and 24 are still blocked. In this circuit, water flows through the line I7, the organ 13, the line to the filter 10 and after exiting the filter through the lines 12 and 21, organ 26 in the drain Vird then by turning the switch 35 to position 1 of the Pre-run initiated, then the organ blocks the line 17 and opens the line 15. Simultaneously with the switch 35 , the changeover points selected for the pre-run are also activated. The beer now flows from the line 15 and via the line 11 into the filter 10, slowly displacing the vaster present there, whereby it mixes with water. Xn the blocked line 17, the electrode 18 continues to be influenced by the water. The electrode 33 also remains exposed to the outflowing water for a short time and thereby keeps the organ 26 open for the drainage.

Then flows at the electrode 33 beer-water mixture with an initially low but slowly increasing beer concentration, then the measured conductivity values change steadily. Reach this first switchover point, then the organ 26 and organ 24 closes opens the line 20 to the supply tank 25. When reached of the 2nd switchover point closes organ 24 and transfers

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Organ 22 clears the way to the storage container 23 for the beer.

After the filtration has ended, the after-run is initiated by moving the switch 35 to position 2. Through this the organ 13 blocks the line 15 and connects the water line 17 with the line 11. At the same time in the control unit 30, the switching points predetermined for the overrun are activated. After the initial drainage of beer, a beer-water mixture flows after a while with slowly increasing water concentration past the electrode 33, then after reaching the respective Changeover points are switched from the storage container 23 to the supply tank 25 and then from the tank 25 to the drain 36.

During the upstream and downstream of the filter 10, the electrode in the line 17 is in constant contact with the water and sends the measured values to control unit 30. If the conductivity of the discharged water changes, then it is determined the computer of the control unit uses the measured values to calculate the ratio of the required shift of the switchover points to the original setting, with the ratio can be the same or selected as desired. The extent to which the switching points are shifted is determined by the Computer then to the electropneumatic control device, which based on the determined changeover points, which can be set separately for pre-run and post-run, performs the required switching of the liquid transport direction.

Claimsι

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Claims (3)

Patent claims : / 1 · ') Method for controlling the pre-carriage and post-carriage Kieselguhr precoat filters through electrical conductivity measurement in the filter outlet, characterized in that that one constantly records the water conductivity value with a measuring electrode in the water supply line leading to the filter and, in the event of a change in conductivity, in the same or any ratio to determined conductivity value the changeover points for the filter material-water mixture changes. 2.) The method according to claim 1, characterized in that the change in the Umsehaltpunkte percentage he follows. 3.) Process according to claims 1 and 2, characterized in that that the setting of the unsalted points for pre-carriage and post-carriage are carried out separately. k.) Device for controlling the pre-run and post-run in kieselguhr precoat filters according to'Anspruch 1, characterized by a control unit, consisting of a computer which, when predetermined water conductivity values change, the ratio of the displacement of the 409883/0627 - Q - Changeover points determined, a switching device to initiate the pre- or post-run and effective switching device of the respective change-over points determined for pre-run or post-run with simultaneous visual display of the respective circuit status, an electropneumatic control device for converting the electrical to pneumatic control signals. 409883/0627 Blank page