WO2008089817A1

WO2008089817A1 - Filter module

Info

Publication number: WO2008089817A1
Application number: PCT/EP2007/010667
Authority: WO
Inventors: Uwe Müller; Wilfried Riggers
Original assignee: Aquaworx Ag
Priority date: 2006-12-08
Filing date: 2007-12-07
Publication date: 2008-07-31
Also published as: DE102006057996A1; DE102006057996B4

Abstract

The present invention relates to a filter module for liquids which comprises two identical filter elements and in each case two identical ultrasonic transmitters, of which each is assigned to a filter element and is arranged to transmit ultrasound in the direction of this filter element. The filter module according to the invention can be used in filter cascades for continuous purification or separation of particles in liquids.

Description

filter module

The present invention relates to a filter module for liquids, which comprises two identical filter elements and in each case two identical ultrasonic transmitters, each of which is assigned to a filter element and is adapted to emit ultrasound in the direction of this filter element. The filter module according to the invention can be used in filter cascades for the continuous purification or separation of particles in liquids.

description

Conventional particle filters or filter systems use filter cartridges or cartridges made of fabric, plastic or coarse metal sieves as filter element. These filter elements are used predominantly as disposable items in a corresponding housing and can occasionally be backwashed manually by flow direction switching or also via a timer. The filter properties are getting worse over time, that is, the filter must be backwashed in an ever smaller time interval and still lose filtration performance, which consequently ultimately requires a replacement of the filter element.

DE 102 58 898 describes a method for inactivating microorganisms using a cavitation generator, in which a high cavitation energy potential is introduced into the liquid and treatment of the liquid takes place by means of native ultrasonic oscillations. Furthermore, a device for inactivating microorganisms is described, wherein a built according to the rotor-stator principle cavitation generator on the opposite working surfaces of the rotor and the stator with different profiles, tear edges and longitudinal grooves is configured.

DE 197 23 798 describes a backwashable filter device with a filter housing, an inlet on one side of the housing and an outlet and a first side and a second side having filter element 36 created. The first side of the filter element is connected to the input and the second side to the output. So that the filter device tion can also detect microscopic elements such as Legionella and spores, it is designed as a ceramic filter.

The object of the invention is to provide a filter of the type described above, with which both the mechanical separation of particles from liquids and the required cleaning of the filter can be carried out in a continuous process in a particularly advantageous manner.

This object is achieved by the filter module characterized in claim 1.

The advantage is achieved that the filter elements achieve an improved and prolonged filtration performance by means of the special backwashing and the cleaning by means of ultrasonic transmitters for the membrane. The cleaning can be done during the continuous operation of the system, so that life is avoided. At the same time less maintenance is required and the operating time is extended. In addition, only a very small volume of backwash liquid must be used. In the case of the separation of particles, these are thus collected by means of the ultrasound generator in a small volume (the backwash liquid), so that further lossy and expensive purification is no longer necessary or limited.

Further developments of the invention are characterized in the subclaims.

Thus, a filter module (1) with a housing (10) with two liquid inlets (6, 8) and at least one liquid outlet (7) is preferred, wherein the housing (10) contains two identical filter elements (2, 2a) are arranged downstream of the first liquid inlet (6) and the second liquid inlet (8) and upstream of the at least one liquid outlet (7) wherein both filter elements (2, 2a) each define a separate filter chamber (4, 4a) and a common filtrate chamber (5) and two identical ultrasonic transmitters (3, 3a), each associated with a filter element (2, 2a) and adapted to emit ultrasound in the direction of this filter element, and wherein the two fluid inlets (6, 8) are further provided with a suitable valve device (9) with a common upstream pressure transducer (11) and in each case a 2-way reflux valve (12, 12 a) is connected upstream with a respective outlet (13). As a valve device (9) a common 3-way valve is preferred but other arrangements (eg two 2-way valves) may be used.

Further preferred is a filter module (1) according to the present invention, comprising at least one further ultrasonic transducer (3b), which sonicates the filtrate chamber (5). The third sounder has the task also in case of possibly volume flow pause (after not using the system) to reduce any resulting biofilm.

Even more preferred is filter module (1) according to the present invention, wherein the filter element (2, 2a) comprises a stainless steel sheet, a foil or other biocompatible material or antibiotically active noble metals or alloys. As filter elements are preferably high-quality stainless steel sheets, films, ceramics or other biocompatible materials for application, conceivable are also precious metals or alloys that allow a bacterial action with their surface. The filter element, and in particular the filter membrane, must withstand the cavity forces created by the ultrasound generator and at the same time have a suitable pore size.

The filter element can be used in a variety of filtration or separation applications requiring a particular hole size (or size in a cascade). A filter module (1) according to the invention is preferred, wherein the filter element (2, 2a) has a hole size for filtration or separation of particles in the range from 2000 μm into the nanoscale (up to 10 nm or even up to 1 nm) , The invention thus can preferably cover a broadband particle range of 2000 μm to <1 nm, more preferably 1000 μm to 10 nm, which allows filtration into the nanoscale. These filter elements are produced according to the filtration requirements with a hole size between 1 nm and 2000 microns according to the current state of the art, e.g. using laser techniques or ceramic techniques.

Further preferred is an inventive filter module (1), wherein the ultrasonic frequency of the ultrasonic transmitter (3, 3a) is adapted to the hole size of the filter element (2, 2a). This prevents damage to the filter element and improves the efficiency of backwashing. Even more preferred is a filter module (1) according to the invention, wherein the spatial distance of the ultrasonic transducer (3, 3a) from the surface of the filter element (2, 2a) is chosen frequency-dependent. Further preferred is therefore an inventive filter module (1), wherein the spatial distance of the ultrasonic transducer (3, 3a) from the surface of the filter element (2, 2a) corresponds to at least half the wavelength in order to avoid reflections of the sound. The two filter chambers (4), with their very small volume, enable a frequency-dependent spatial distance between the ultrasonic transducer (3) and the membrane surface (2), which corresponds to at least half the wavelength in order to avoid reflections of the sound. This allows a thorough and gentle cleaning due to high cavitation effects at close range.

Still further preferred is a filter module (1) according to the invention, further comprising a permanent antibiotic coating of all surfaces coming into contact with liquid, in particular with nano-silver particles. This coating prevents biofilm formation on the liquid-carrying components of the filter module, in particular for longer life, and facilitates the replacement of such possibly resulting films by the sound.

A further aspect of the present invention then relates to a filter cascade (20) which comprises at least two filter modules (1) connected in series according to the invention, wherein the filter modules (1) are each characterized by a different hole size of the filter elements (2, 2a).

Preferred is a filter cascade (20) of the present invention, further comprising a volume flow meter (21) connected downstream of the last filter module. The flow meter (21) controls the flow rate through the cascade and measures its capacity, e.g. to indicate a possible replacement. The backwashing in the individual filter module is determined by the flow meter (11), (1 Ia) and the corresponding differential pressure.

Preferred is a filter module (1) or a filter cascade of the present invention, wherein the housing is designed to be portable. The filter module can thus easily be used outdoors, e.g. in case of disaster, be transported, where it is configured correspondingly small.

A further aspect of the present invention then relates to a method for filtering a liquid, comprising the steps of a) providing a filter module (1) the present invention or a filter cascade (20) of the present invention, and b) reciprocal introduction of the volume flow of the liquid to be filtered through the two inputs (6) and (8) by means of the 3-way valve (9) into the filter module (1) ,

A further preferred method according to the invention is that the pressure sensor (11) receives the input pressure into the respective filter module (1) and correspondingly controls a change between the two inputs (6, 8) and a required backwashing via the 3-way valve (10).

Further preferred is an inventive method, comprising a mutual backwashing of the filter elements (2, 2a) via the backwash valves (12) or (12a). According to the invention, the ultrasonic transmitter (3, 3a) of the corresponding filter element (2, 2a) to be backflushed is activated during rewinding.

When carrying out the method according to the invention, the backwashing can take place with reduced and pulsed flow. The volume flow for the backwashing is thereby determined via a suitable, e.g. Solenoid valve (12 or 12a) in the drain (13) preferably clocked so that at the diaphragm (2) additional pressure peaks accelerate the cleaning process, i. Dissolve the degradation of particles or other substances added to the filter from the membrane.

A further aspect of the present invention then relates to a process in which, by means of the backwashing, fractionation of the particles contained in the liquid takes place, the fraction (s) being collected in the effluent (13). These particles may be biological particles, e.g. Bacteria, or blood or serum components, such as platelets or blood cells. Depending on the size of the filter, coarser components or even viral particles can be filtered off or separated.

Further preferred is an inventive method, wherein the filtrate leaves the filter module (1) or the filter modules with a continuous volume flow through the liquid outlet (7).

A further aspect of the present invention then relates to a method according to the invention, which further comprises a subsequent water treatment, in particular drinking water treatment. tion, advantageously independent of the turbidity and particle load comprises. By means of the present invention, in particular, large quantities of drinking water can be continuously processed without the filter having to be changed frequently. So can be advantageously ensured with fewer staff a supply of drinking water, eg in drought areas. With the extension to a multi-stage filter cascade contaminated drinking water can be filtered to clean drinking water without chemical additives. With this invention, water treatment equipment can be added, which require a pre-filter.

As described above, the liquid to be filtered may be selected from biological fluids such as blood, urine or lymphatic fluid. However, other aqueous or oily liquids, such as natural or synthetic oils, or coolants may also be filtered. Thus, the filter module may e.g. find use as an oil filter in shipbuilding engines.

Yet another aspect of the present invention then relates to the use of a filter module of the present invention or a filter cascade of the present invention for filtration and / or fractionation of biological fluids such as blood or blood components, serum, urine or lymphatic fluid as described above.

Yet another aspect of the present invention then relates to the use of a filter module of the present invention or a filter cascade of the present invention for filtration of water, especially water treatment, as described above. With the extension to a multi-stage filter cascade contaminated drinking water can be filtered to clean drinking water without chemical additives.

Yet another aspect of the present invention then relates to the use of a filter module of the present invention or a filter cascade of the present invention as a prefilter for water treatment devices as described above.

Yet another aspect of the present invention then relates to the use of a filter module of the present invention or a filter cascade of the present invention for filtering oil or coolants in engines, as described above. The invention makes it possible to use stainless steel membranes (2), or filter elements with a special backwashing and automatic cleaning means defined for the membrane ultrasonic frequency and power so that the filtration performance is maintained as long as possible.

The invention makes it possible to effectively clean the respectively backwashed membrane (2) by an ultrasonic frequency (3) adapted to the hole diameter of the membrane. During rewinding the ultrasound (3) is activated only for this membrane (2). The volume flow for the backwashing is thereby determined via a suitable, e.g. Solenoid valve (12 or 12a) in the drain (13) preferably clocked so that at the diaphragm (2) additional pressure peaks accelerate the cleaning process, i. Dissolve the degradation of particles or other substances added to the filter from the membrane.

The backwash volume to be discarded is only a fraction of the filtration volume flow through this membrane. Since it would inevitably come to a discontinuous volume flow with only one filter element, each filter module (1) according to the invention with two identical filter elements (2, 2a) equipped to realize a continuous flow through the filter module.

Since it makes sense for certain processes to use a filtering in ever finer filter stages or cascades, the invention makes it possible to realize a filter section with a defined input and output particle size for transparent and non-transparent liquids. In this case, particles are separated according to their size and can be collected via the rewind valves (12 and 12a) and possibly supplied for further use. It can be dispensed with the replacement of the filter element (or the membranes).

The invention will now be further elucidated hereinafter with reference to the accompanying drawings without, however, being limited thereto. In the figures shows:

Figure 1 is a schematic view of a preferred embodiment of a filter module of the invention.

Figure 2 is a schematic view of a preferred embodiment of a filter cascade of the invention (in this case with four filter modules of the invention). The filter module (1) shown in Figure 1 consists of a housing, preferably made of pressure-resistant material such as a stainless steel pipe. The filter module contains two filter elements (2) of the same design and hole size. At the ends of the filter module (1) (ie the tube) is in each case a structurally identical ultrasonic transducer (3) which is aligned directly on the input chamber (4) on the filter element (2) and this sonicated at backwashing.

Between the two filter elements is the filtrate chamber (5) and the outlet (7) for the filtrate. The filtrate chamber (5) is sonicated by a third optional ultrasonic transducer (3).

Through the two inputs (6) and (8) the volume flow flows into the filter module alternately. The filtrate leaves the filter module (1) with a continuous volume flow through the outlet (7). The changeover between the two inputs (6 and 8) is controlled by the process with the required backwashing via a 3-way valve (9) adapted to the volume flow. In front of the 3-way valve (9), a pressure sensor (11) measures the inlet pressure in the respective filter module.

By the parameters of the pressure pickup input (and optional output) of the module

(11) the required backwash process and change to the other input (6 or 8) is controlled. The respective backwashing takes place alternately via the backwash valves

(12) or (12a), which are preferably designed as a 2-way valve. The two backwash valves (12 and 12a) need not be designed for the volume flow, the backwashing is preferably carried out with reduced and pulsed flow.

The backwashed volume is collected in the drain (13) and either discarded or reused, e.g. further concentrated or processed.

With reference to FIG. 2, a filter module according to the invention can be used as a filter cascade by successively switching at least two filter modules (1) with at least two different filter elements (2) with different filter hole size, in which case the filtration performance of the required particle size can be adjusted. The last one Filter module of the cascade can preferably be followed by a volumetric flow meter (21). Several fractions can be recovered from the effluents (13).

The features disclosed in the foregoing description, claims and drawings may be significant to the practice of the invention in its various forms both individually and in any combination thereof.

M31267

LIST OF REFERENCE NUMBERS

O) Filter module

(2), (2a) Filter element

(3), (3a), (3b) Ultrasonic transducer

(4), (4a) filter chamber

(5) filtrate chamber

(6) liquid inlet

(7) Fluid outlet

(8) liquid inlet

(9) 3-way valve

(10) housing

(11), (I Ia) pressure transducer

(12) (12a) 2-way return valve with

(13) outflow

(20) Filter Cascade

(21) Volume flow meter

Claims

claims

A filter module (1) comprising a housing (10) having two fluid inlets (6, 8) and at least one fluid outlet (7), the housing (10) including two equal filter elements (2, 2a) respectively downstream of the first fluid inlet (6) and the second liquid inlet (8) and upstream of the at least one liquid outlet (7) are arranged wherein each filter elements (2, 2a) each define a separate filter chamber (4, 4a) and a common filtrate chamber (5) and two in each case Ultrasonic transducer (3, 3a), each of which is associated with a filter element (2, 2a) and adapted to emit ultrasound in the direction of this filter element, and wherein the two fluid inlets (6, 8) further comprises a common 3-way valve (9 ) is connected upstream with a common upstream Druckaufhehmer (11) and in each case a 2-way return valve (12, 12 a), each with a drain (13).

2. Filter module (1) according to claim 1, comprising at least one further ultrasonic transducer (3b), which sonicates the filtrate chamber (5).

3. Filter module (1) according to claim 1 or 2, wherein the filter element (2, 2a) comprises a stainless steel sheet, a film or other biocompatible material or antibiotically active noble metals or alloys.

4. Filter module (1) according to one of claims 1 to 3, wherein the filter element (2, 2a) has a hole size for a filtration of particles in the range of 2000 .mu.m to <1 nm, preferably 1000 .mu.m to 10 nm.

5. Filter module (1) according to one of claims 1 to 4, wherein the ultrasonic frequency of the ultrasonic transmitter (3, 3a) is adapted to the hole size of the filter element (2, 2a).

6. Filter module (1) according to one of claims 1 to 5, wherein the spatial distance of the ultrasonic transmitter (3, 3a) from the surface of the filter element (2, 2a) is selected frequency-dependent.

7. Filter module (1) according to claim 6, wherein the spatial distance of the ultrasonic transmitter (3, 3a) from the surface of the filter element (2, 2a) corresponds to at least half the wavelength in order to avoid reflections of the sound.

8. Filter module (1) according to any one of claims 1 to 7, further comprising a permanent antibiotic coating of all liquid coming into contact surfaces, in particular with nano-silver particles.

9. filter cascade (20), comprising at least two filter modules (1) connected in series according to one of claims 1 to 8, wherein the filter modules (1) are each characterized by a different hole size of the filter elements (2, 2a).

10. Filter cascade (20) according to claim 9, further comprising a last filter module downstream volume flow meter (21).

11. Filter module (1) or filter cascade (20) according to any one of claims 1 to 10, wherein the housing is mobile, in particular rollable or portable, is configured.

12. A method for filtering a liquid, comprising the steps of a) providing a filter module (1) or a filter cascade (20) according to any one of claims 1 to 11, and b) mutual introduction of the volume flow of the liquid to be filtered through the two Inputs (6) and (8) by means of the 3-way valve (9) in the filter module (1) inside.

13. The method of claim 12, wherein the pressure transducer (11) receives the input pressure in the respective filter module (1) and correspondingly controls a change between the two inputs (6, 8) and a required backwashing via the 3-way valve (9).

14. The method of claim 12 or 13, further comprising a mutual backwashing of the filter elements (2, 2a) via the backwash valves (12) or (12a).

15. The method according to any one of claims 12 to 14, wherein during the rewinding of the ultrasonic transmitter (3, 3a) of the back-flushed corresponding filter element (2, 2a) is activated.

16. The method according to any one of claims 13 to 15, wherein the backwashing is done with reduced and clocked flow.

17. The method according to any one of claims 13 to 16, wherein by means of the backwashing a fractionation of the particles contained in the liquid takes place, wherein the fractions) in the outflow (13) are collected.

18. The method according to any one of claims 12 to 17, wherein the filtrate leaves the filter module (1) or the filter modules with a continuous flow through the liquid outlet (7).

19. The method according to any one of claims 12 to 18, further comprising a subsequent water treatment, in particular drinking water treatment.

20. A method according to any one of claims 12 to 19, wherein the liquid is selected from aqueous, oily or biological liquids, such as water, natural or synthetic oils, blood or blood components, serum, urine, lymph or coolant.

21. Use of a filter module or a filter cascade according to any one of claims 1 to 11 for the filtration and / or fractionation of biological fluids, such as blood or blood components, serum, urine or lymphatic fluid.

22. Use of a filter module or a filter cascade according to one of claims 1 to 11 for the filtration of water, in particular for water treatment.

23. Use of a filter module or a filter cascade according to any one of claims 1 to 11 as a pre-filter for water treatment equipment

24. Use of a filter module or a filter cascade according to one of claims 1 to 11 for the filtration of oil or coolants in engines.