DE102010054720A1 - Filtration device for filtering fluid e.g. beer, has pipe for dissipating filtrate from filter arrangement, and piston arrangement producing pressure surges for back-flushing filtrate through filtration device for cleaning filtration device - Google Patents

Abstract

The device has a filtration circuit (5) comprising a filter arrangement (6) i.e. membrane arrangement, and a pipe (7) for dissipating filtrate from the filter arrangement. A piston arrangement (10) produces pressure surges for back-flushing the filtrate through the filtration device for cleaning the filtration device. The piston arrangement has a pressure area that is loaded with a drive fluid and two cylinders that are designed with different inner diameters. An opening is formed in an intermediate area between pistons of the piston arrangement. An independent claim is also included for a method for executing a backwashing of a filtration device.

Description

The invention relates to a filtration device and a method for cleaning a filtration device.

Even with a cross-flow filtration forms with time on the surface of the actual filter, such as a membrane, a filter cake, which impedes the filtration.

To counteract this effect, it is u. a. known to perform a periodic backwashing with filtrate contrary to the filtration direction, z. B. in the filtration of wine and beer. For backwashing, pumps and backwash valves are used. It is also known to carry out a backwashing for cleaning with a cleaning fluid, which may be a cleaning fluid or a gas. This is disadvantageous that the product u. U. comes into contact with the cleaning fluid.

Another disadvantage of the known backwashing method is the significant time extension of the filtration cycle associated with the cleaning.

The object of the invention is to simplify the cleaning of filtration devices, in particular of cross-flow filtration devices.

The invention solves this problem by the subject matter of claims 1 and 7.

According to the invention, a piston assembly is used for backwashing, with which it is possible to generate short intense pressure surges, with which filtrate is flushed back through the membranes to clean them. The particular advantages of this arrangement will be explained in more detail below.

Advantageous embodiments of the invention can be found in the dependent claims.

The invention will be described in more detail with reference to the drawing with reference to an embodiment. It shows:

1 a schematic representation of a filtration device according to the invention; and

2 a schematic representation of a piston unit.

1 schematically illustrates the construction of a filtration apparatus designed to carry out cross-flow filtration.

The filtration device here has a container 1 for a liquid to be filtered 2 on, over a wire 3 and possibly a pump 4 with a filtration circuit 5 is connected and to feed the filtration circuit 5 used with a liquid to be filtered.

The liquid to be filtered circulates in the filtration circuit 5 Here's a pump to circulate the liquid 25 and flows through at least one (or more) filter arrangement (s) 6 in which it is filtered in a cross-flow process or crossflow process. In the cross-flow filtration, a cross-flow is generated which flows along the actual filter medium, for example a membrane filter, wherein the liquid to be filtered passes through the pores of the membrane. The resulting filtrate or permeate is passed through a conduit 7 - here with a valve 8th can be shut off, derived, for example, in a container 9 while the remaining retentate is circulated in the filtration loop and further concentrated until the filtration cycle is complete. Possibly. In this case, it is also possible to meter in additional liquid to be filtered.

The formation of excessive deposits on the filter assembly 6 , In particular, the membrane filter assembly, by means of an advantageous backwashing of the filter assembly 6 counteracted.

For backwashing is a piston assembly 10 used, with which it is possible to generate short intense pressure surges, with which the filtrate is flushed back through the membranes to clean them.

A schematic representation of a preferred embodiment of this piston assembly 10 shows 2 ,

The preferred piston assembly 10 has two axially juxtaposed cylinder 11 . 12 different inside diameter. In each of the cylinders 11 . 12 is a piston 13 . 14 slidably guided. The two pistons 13 . 14 are with a cylinder rod 15 coupled together so that they are only displaced together.

The piston 13 in the first cylinder 11 larger diameter has an area A and the piston 14 in the cylinder 12 smaller diameter a surface a.

The cylinder chamber - subsequently also pressure chamber 21 called - at the of the piston rod 15 opposite side of the piston 13 in the cylinder 11 larger diameter has an inlet valve 16 and an exhaust valve 17 for a driving fluid such as a gas or a hydraulic fluid.

The cylinder chamber - subsequently also product space 20 called - at the of the piston rod 15 opposite side of the piston 14 in the cylinder 11 smaller diameter, however, is a valve 18 and possibly a branch line 19 (please refer 1 ) with the line 9 for draining filtrate from the filtration device.

Such product can be in the product space 20 on the from the piston rod 15 opposite side of the piston 13 smaller diameter flow, which is for backwashing the filtration assembly 6 is usable.

Optional is in the gap 22 between the pistons 13 . 14 an opening 23 provided the space 22 with the environment 24 combines. At the opening 23 a valve may be provided and / or a connection possibility for a cleaning device. The opening 23 is used in particular for the necessary pressure equalization in the intermediate space 22 between the pistons 13 . 14 due to the different inner diameter of the cylinder. By connecting the cleaning device, the gap 22 if necessary, be rinsed to clean it.

With this arrangement, a cleaning of the filtration arrangement can be carried out, for example, in the following manner or according to the following method: In a step a), the outlet valve 17 opened so that in the pressure room 21 If necessary, the gas contained in the first cylinder can escape and the product space can escape 20 can fill with filtrate. Optional - but not mandatory - is here the valve 8th be closed to the line 7 to close the filtrate, allowing filtrate from the product room 20 only in the filtration device 6 can flow back.

When this is completed, in a step b) the outlet valve 18 closed and the piston assembly is by loading the pressure chamber 21 with the driving fluid (for example, air; 1 purely schematically fed from a pressure vessel 26 ).

Then, in a step c), the exhaust valve 18 opened, allowing the filtrate abruptly into the pipe 7 and through them into the filter assembly 6 flows back, which is a backwashing of the actual filter, in particular the membrane filter, the filter assembly 6 causes.

Possibly. the steps a) to c) are repeated one or more times per cleaning cycle in order to increase the cleaning effect.

The cleaning cycle can be repeated periodically or can be repeated in a regulated manner as a function of a parameter to be determined.

By the translation A / a of the surfaces A and a of the piston 13 . 14 results in a beneficial increase in product pressure in the product space 20 opposite to the air pressure in the pressure chamber 21 from A / a. Preferably, A> 1.3 a.

The opening 23 compensates for the displaced volumes and protects seal leaks on the pistons 13 . 14 ,

Optionally, to the connection or a connection 23 the cleaning device for performing a cleaning of the gap 22 be connected, which in particular in the processing of sensitive products -. B. drinks - is an advantage.

A particular advantage of this procedure is that the current filtration or production is not or at least virtually not interrupted to carry out a cleaning.

• – Die Kolbenanordnung 10 sichert eine schlagartige, besonders effektive sowie klar definierte, wiederholbare Rückspülung und Reinigungswirkung, deren Charakteristik und Wirkung wesentlich durch das Verhältnis der Kolbenflächen A/a beeinflusst wird;
• – Durch die optionale vorteilhafte Übersetzung A/a kann auch mit üblichen Steuerluftdrücken von z. B. 6 bar ein höherer Produktdruck von z. B. 10 bar erreicht werden. Dies ist beispielsweise bei CO2-haltigen Produkten vorteilhaft, die immer über dem Sättigungsdruck gehalten werden müssen, also beispielsweise bei der Verarbeitung von Bier oder Sekt.
• – Durch die gewählte vorteilhafte Kolbenanordnung 10 der 2 ist der Druckraum 21 vom Produktraum 20 klar getrennt, so dass der letztere – anders als bei der direkten Injektion von Gasen in die Filteranordnung 7 – durch den Reinigungsvorgang nicht mit dem Gas in Berührung kommt, so dass beispielsweise keine Kontaminationsgefahr oder Oxidationsgefahr besteht.
• – Die Produktsicherheit wird durch die optionale (Leckage-)Öffnung 23 weiter erhöht.
• – Durch die Option der Reinigung des Zwischenraums 22 ist die Anordnung besonders hygienisch.

In addition, however, the device according to the invention and the cleaning method according to the invention also offer further advantages:

• - The piston assembly 10 ensures a sudden, particularly effective and well-defined, repeatable backwashing and cleaning action, whose characteristics and effect are significantly influenced by the ratio of the piston area A / a;
• - By the optional advantageous translation A / a can also with conventional control air pressures of z. B. 6 bar a higher product pressure of z. B. 10 bar can be achieved. This is advantageous, for example, for products containing CO2, which always have to be kept above the saturation pressure, for example when processing beer or sparkling wine.
• - By the selected advantageous piston assembly 10 of the 2 is the pressure room 21 from the product room 20 clearly separated, so the latter - unlike the direct injection of gases into the filter assembly 7 - Does not come into contact with the gas through the cleaning process, so that, for example, there is no risk of contamination or oxidation.
• - Product safety is ensured by the optional (leakage) opening 23 further increased.
• - By the option of cleaning the gap 22 the arrangement is particularly hygienic.

Finally, it should be mentioned that the piston arrangement 10 can be realized inexpensively with simple means.

Of course, in addition to the cleaning with the piston assembly also another known cleaning method can be used, for example, to flush the filtration device at longer intervals in addition to a cleaning liquid.

As a further advantage, it should be mentioned that the backwashing pressures in the piston arrangements are higher than in pumps for backwashing, which accelerates and improves the cleaning. Pumps are at a "Delta P" of typically 2 bar, which are started relatively slowly. By contrast, significantly higher pressures can be achieved with the piston arrangement, preferably those of more than 3 bar, in particular more than 4 bar. Good to reach, for example, 5 bar as shock or pressure increase on the filter, which also has the advantage that a more uniform loading of the membrane is effected because the fluid is not slow to seek the path of least resistance.

LIST OF REFERENCE NUMBERS

1

container

2

liquid

3

management

4

pump

5

Filtration circuit

6

A filter assembly

7

management

8th

Valve

9

container

10

piston assembly

11, 12

cylinder

13, 14

piston

15

cylinder rod

16

intake valve

17

outlet valve

18

Valve

19

branch line

20

product space

21

pressure chamber

22

gap

23

opening

24

Surroundings

25

pump

26

pressure vessel

Claims (12)

Filtration device for the filtration of a liquid, in particular by means of a cross-flow filtration, with a filtration circuit ( 5 ) with a filter arrangement ( 6 ), in particular a membrane arrangement, and with a line ( 7 ) for the removal of filtrate from the filter assembly ( 6 ), characterized by a piston arrangement ( 10 ) for generating pressure surges, with which the filtrate through the filtration device ( 6 ) is backwashed to clean it. Filtration device according to claim 1, characterized in that the piston arrangement ( 10 ) a pressure chamber ( 21 ), which can be acted upon by a drive fluid and a product space ( 20 ), with the line ( 7 ) for the removal of filtrate from the filter assembly ( 6 ) connected is. Filtration device according to claim 1, characterized in that the piston arrangement comprises two cylinders ( 11 . 12 ) of different internal diameters, wherein in each of the cylinders ( 11 . 12 ) one piston each ( 13 . 14 ), which are coupled together, so that they are only displaceable together, wherein the piston ( 13 ) in the first cylinder ( 11 ) of larger diameter has an area A and the piston ( 14 ) in the cylinder ( 12 ) smaller diameter a relative to the surface A smaller area a. Filtration device according to claim 3, characterized in that the cylinder space - the pressure chamber ( 21 ) - at the of the piston rod ( 15 ) side facing away from the piston ( 13 ) in the cylinder ( 11 ) having an inlet and an outlet for the driving fluid such as a gas or a hydraulic fluid. Filtration device according to claim 2, 3 or 4, characterized in that the cylinder space - the product space ( 20 ) - at the of the piston rod ( 15 ) side facing away from the piston ( 14 ) in the cylinder ( 11 ) of smaller diameter preferably via a valve ( 18 ) with the line ( 7 ) for draining filtrate from the filter assembly ( 6 ), so that product in the product space ( 20 ) on the piston rod ( 15 ) side facing away from the piston ( 13 ) of smaller diameter, which is suitable for backwashing the filtration arrangement ( 6 ) is usable. Filtration device according to one of the preceding claims, characterized in that in a space ( 22 ) between the pistons ( 13 . 14 ) an opening ( 23 ) is provided, which the space ( 22 ) with the environment ( 24 ) connects. Method for carrying out a backwashing of a filter arrangement ( 6 ), in particular a membrane arrangement, a filtration device one or more of the preceding claims, comprising the following steps: a. the product room ( 19 ) is filled with filtrate; b. the outlet valve ( 18 ) is closed and the piston assembly ( 10 ) is achieved by filling the pressure chamber ( 21 ) is biased with the drive fluid; and c. the outlet valve ( 18 ) is then opened, so that the filtrate in the line ( 9 ), which causes a backwashing of the filter assembly ( 6 ) causes. A method according to claim 7, characterized in that the steps a. to c. be repeated one or more times. A method according to claim 8, characterized in that the steps a. to c. be repeated periodically or regulated depending on a characteristic. Method according to one of claims 7 to 9, characterized in that a cleaning of the gap ( 22 ) he follows. Method according to one of the preceding claims, characterized in that the continuous filtration is continued during the cleaning and is not interrupted. Method according to one of the preceding claims, characterized in that with the piston assembly cleaning pulses with a pressure of more than 3 bar, in particular more than 4 bar are generated.

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