WO2017005972A1

WO2017005972A1 - Filter element with conductive breaking indicator

Info

Publication number: WO2017005972A1
Application number: PCT/FI2016/050480
Authority: WO
Inventors: Antti VESALA; Mika ILLI; Matti Luukkonen; Ismo JUVONEN
Original assignee: Outotec (Finland) Oy
Priority date: 2015-07-03
Filing date: 2016-06-29
Publication date: 2017-01-12
Also published as: FI20155527A; BR212018000148U2; BR212018000148Y8; CL2017003410U1; BR212018000148Y1

Abstract

A filter apparatus, comprising a filter formed by a plurality of filter elements, the filter arranged around a central shaft. The central shaft and the filter being rotatable around longitudinal axis of the central shaft. The filter apparatus further comprises an identification unit arranged to store an identification code specific for the filter element, a receiver apparatus comprising a receiver means arranged to receive wirelessly an identification signal comprising said identification code, and a forwarding means for forwarding an output signal based on said identification code.

Description

FILTER ELEMENT WITH CONDUCTIVE BREAKING INDICATOR

Background

The present invention relates to filter apparatuses having filter comprising multiple filter elements.

The invention further relates to a method for controlling filter apparatus having filter comprising multiple filter elements.

Filtration is a widely used process whereby a slurry or solid liquid mixture is forced through a media, with the solids retained on the media and the liquid phase passing through. This process is generally well understood in the industry. Examples of filtration types include depth filtration, pressure and vacuum filtration, and gravity and centrifugal filtration.

Both pressure and vacuum filters are used in the dewatering of mineral concentrates. The principal difference between pressure and vacuum filters is the way the driving force for filtration is generated. In pressure filtration, overpressure within the filtration chamber is generated with the help of e.g. a diaphragm, a piston, or external devices, e.g. a feed pump. Consequently, solids are deposited onto the filter and filtrate flows through into the filtrate channels. Pressure filters often operate in batch mode because continuous cake discharge is more difficult to achieve.

The cake formation in vacuum filtration is based on generating suction within the filtrate channels. The most commonly used filter media for vacuum filters are filter cloths and coated media, e.g. the ceramic filter medium. These filter media are commonly used in filter apparatuses having filter comprising multiple filter elements, e.g. in rotary vacuum disc filters and rotary vacuum drum filters.

Rotary vacuum disc filters are used for the filtration of relatively free filtering suspensions on a large scale, such as the dewatering of mineral concentrates. The dewatering of mineral concentrates requires large capacity in addition to producing a cake with low moisture content. Such large processes are commonly energy intensive and means to lower the specific energy consumption are needed. The vacuum disc filter may comprise a plurality of filter discs arranged in line co-axially d around a central pipe or shaft. Each filter disc may be formed of a number of individual filter elements or sectors, called filter plates, that are mounted circumferentially in a radial plane around the central pipe or shaft to form the filter disc, and as the shaft is fitted so as to revolve, each filter plate or sector is, in its turn, displaced into a slurry basin and further, as the shaft of rotation revolves, rises out of the basin. When the filter medium is submerged in the slurry basin where, under the influence of the vacuum, the cake forms onto the medium. Once the filter sector or plate comes out of the basin, the pores are emptied as the cake is deliquored for a predetermined time which is essentially limited by the rotation speed of the disc. The cake can be discharged by a back-pulse of air or by scraping, after which the cycle begins again. Whereas the use of a cloth filter medium requires heavy duty vacuum pumps, due to vacuum losses through the cloth during cake deliquoring, the ceramic filter medium, when wetted, does not allow air to pass through which does not allow air to pass through, which further decreases the necessary vacuum level, enables the use of smaller vacuum pumps and, consequently, yields significant energy savings.

Vacuum filtration is based on producing a suction within the filtrate channels and thereby forming a cake of mineral on the surface of the filter medium. The most commonly used filter elements in vacuum filters are filter cloths and ceramic filters.

Rotary vacuum drum filters are used for the filtration of relatively free filtering suspensions on a large scale, such as the dewatering of mineral concentrates. The dewatering of mineral concentrates requires large capacity in addition to producing a cake with low moisture content. The vacuum drum filter may comprise a cylindrical support structure rotating around a longitudinal shaft forming a centre axis for the drum. There are a plurality of filter elements or plates arranged on the outer surface of the cylinder. Each filter plate forms a portion of the cylindrical outer surface of the cylinder. Each filter plate is during each revolution of the shaft displaced for a certain period into a slurry basin situated below the shaft. The filter plate rises out of the basin when the revolution of the shaft proceeds. When the filter plate is submerged in the slurry basin a cake forms onto the outer surface of the filter plate due to the vacuum within the filter plate. Once the filter plate comes out of the basin, the pores are emptied as the cake is deliquored for a predetermined time which is essentially limited by the rotation speed of the drum. The cake can be discharged by a back- pulse of air or by scraping, after which the cycle begins again. The filter elements of rotary vacuum drum filters are advantageously made of porous ceramic. The filter elements contain micro sized pores, i.e. micropores, that create strong capillary action in contact with liquid. This microporous filter medium allows only liquid to flow through.

Common for all said filters is typically a great number of filter elements. This arises a problem that the management of the filter elements, i.e. their history, e.g. installation date or operating hours of a specific element, is very difficult and burdensome to handle.

Brief description

Viewed from a first aspect, there can be provided a filter apparatus, comprising a filter formed by a plurality of filter elements, the filter arranged around a central shaft, the central shaft and the filter being rotatable around longitudinal axis of the central shaft, wherein the filter apparatus further comprises an identification unit arranged to store an identification code specific for the filter element, a receiver apparatus comprising a receiver means arranged to receive wirelessly an identification signal comprising said identification code, and a forwarding means for forwarding an output signal based on said identification code.

Thereby a filter apparatus wherein the management of the filter elements is easy and simple may be achieved.

In one embodiment, the identification unit is a RFID tag and the receiver apparatus comprises a RFID receiver, the identification signal being thus a radio frequency signal. An advantage is that RFID components and systems may be small-sized and simple to install and use.

In one embodiment, the identification unit is an optically readable identification unit and the receiver apparatus comprises an optical reader, the identification signal being thus an optical signal. An advantage is that, in embodiment where the identification unit is arranged in a filter element, the identification signal can be read e.g. by a camera of a mobile phone e.g. in manufacturing process of the filter element, during storing and transportation of the filter element and/or in the element attached to the filter apparatus.

In one embodiment, the identification unit is arranged in the filter element. An advantage is that the identification of the filter element may be found out even if the filter element is not attached to the filter apparatus.

In one embodiment, the receiver means comprises an antenna that is arranged in an antenna module, said antenna module comprising a frame supporting the antenna at a reading distance from the filter. An advantage is that the installation of the receiver means is easy.

In one embodiment, the reading distance is selected in range of 1 cm - 3 m, preferably 2 cm - 2 m, more preferably 5 cm - 70 cm. A shorter reading distance may improve the reading reliability. A longer reading distance may widen the reading area of the antenna.

In one embodiment, the antenna module comprises a distance adjusting means for adjusting the reading distance. An advantage is that the reading distance is easily optimised.

In one embodiment, the antenna module comprises an alignment means for adjusting the alignment of the antenna module relative to the identification unit. An advantage is that the antenna(s) can be set easily in a position where the receiving of the identification signal is optimized.

In one embodiment, the receiver means is fixed in the filter appa- ratus. An advantage is that the correct position of the receiver means relative to the filter elements may be easily maintained.

In one embodiment, the receiver means is fixed in a support structure separate from the filter apparatus. An advantage is that the receiver means may be used even if the filter apparatus has no room in its structure for fixing the receiver means.

In one embodiment, the antenna module comprises module elements that are connected consecutively to each other by attachment means. An advantage is that the antenna module may be transported in relative small- sized parts.

In one embodiment, the filter apparatus comprises two or more consecutive co-axial filter discs with sectors formed by a plurality of sector-shaped filter elements, and two or more one receiver apparatus, respectively, arranged for receiving the identification code from the transmitter apparatuses of one specific filter disc only. An advantage is that each of the receiver apparatuses may be positioned close to the transmitter apparatuses to be read.

In one embodiment, the antenna module is arranged to locate above the filter discs in a position between 9 o'clock and 16 o'clock, preferably between 1 1 o'clock - 15 o'clock, more preferably 1 1 o'clock - 14 o'clock viewing along the longitudinal axis where the rotation of the filter takes place coun- terclockwise. An advantage is that the reading area of the antenna may be as wide as possible and that the antenna module may not hinder operators of the filter apparatus in their work, especially during changing work of the filter elements.

In one embodiment, the filter apparatus comprises a filter drum, wherein the filter element is a part of outer surface of the filter drum, and a washing station and a slurry basin, wherein the antenna module is arranged to locate between said washing station and slurry basin such that, in direction of rotation of the filter, the antenna module follows the washing station and the slurry basin follows the antenna module. An advantage is that the reading area of the antenna may be as wide as possible and that the antennas may be well protected from water, dust and external impacts.

In one embodiment, the identification codes from multiple receiver apparatus are supplied to the forwarding means common for said multiple receiver apparatus. An advantage is that the number of the components may be reduced.

In one embodiment, the filter element comprises an indicator arranged to generate a break indication upon breakage of said filter element, and the transmitter apparatus for wireless communication is arranged to communicate a break signal based on said break indication to the receiver apparatus. An advantage is that a breaking or broken filter element may be detect- ed quickly and thus further damages of the filter apparatus may be limited.

In one embodiment, the wireless communication is based on RFID communication and the break signal is arranged to be received by the same antenna as the identification signal of the corresponding filter element. An advantage is that the embodiment is simple and cost-effective.

In one embodiment, the antenna module comprises a light element arranged to lighten the filter. An advantage is that the operational safety of the apparatus may be improved.

In one embodiment, the receiver apparatus is a hand-held device. An advantage is that the embodiment is very cost-effective.

Viewed from a further aspect, there can be provided a method for controlling the filter apparatus claimed in claim 1 , the method comprising:

- creating database on the filter elements of the filter apparatus on the basis of the identification codes, and

- updating automatically the database in case of change of one or more filter element(s). Thereby a method facilitating of the management of the filter elements may be achieved.

The filter apparatus and the method are characterised by what is stated in the corresponding independent claims. Some other embodiments are characterised by what is stated in the other claims. Inventive embodiments are also disclosed in the specification and drawings of this patent application. The inventive content of the patent application may also be defined in other ways than defined in the following claims. The inventive content may also be formed of several separate inventions, especially if the invention is examined in the light of expressed or implicit sub-tasks or in view of obtained benefits or benefit groups. Some of the definitions contained in the following claims may then be unnecessary in view of the separate inventive ideas. Features of the different embodiments of the invention may, within the scope of the basic inventive idea, be applied to other embodiments. Brief description of figures

Some embodiments illustrating the present disclosure are described in more detail in the attached drawings, in which

Figure 1 is a perspective top view illustrating an exemplary filter apparatus,

Figure 2 is a cutaway view of the filter apparatus shown in Figure 1 ,

Figure 3 is a perspective top view illustrating an exemplary module element,

Figure 4 is a cutaway view illustrating details of the antenna module shown in Figure 3,

Figure 5 is a perspective top view illustrating another exemplary filter apparatus,

Figures 6A and 6B illustrate exemplary filter elements, and Figure 7 illustrates an exemplary method for controlling a filter apparatus.

In the figures, some embodiments are shown simplified for the sake of clarity. Similar parts are marked with the same reference numbers in the figures.

Detailed description

Principles of the embodiments can be applied for drying or dewater- ing fluid materials in any industrial processes, particularly in mineral and min- ing industries. In embodiments described herein, a material to be filtered is referred to as a slurry, but embodiments are not intended to be restricted to this type of fluid material. The slurry may have high solids concentration, e.g. base metal concentrates, iron ore, chromite, ferrochrome, copper, gold, cobalt, nickel, zinc, lead and pyrite.

Figure 1 is a perspective top view illustrating an exemplary filter apparatus, and Figure 2 is a cutaway view of the filter apparatus shown in Figure 1 .

The filter apparatus 1 shown here is a disc filter apparatus that comprises a filter 2 consisting of several consecutive co-axial filter discs 16 arranged in line co-axially around the central shaft 4 of the filter 2.

The filter 2 is supported by bearings on a frame 23 of the filter apparatus 23 and is rotatable about the longitudinal axis X of the filter 2 such that the lower portion of the filter 2 is submerged in a slurry basin 24 located below the filter 2. The filter is rotated by e.g. an electric motor not shown in Figure 1 .

The number of the filter discs 16 may range from 2 to 20, for example. The diameter of each disc 16 may be ranging from 1 .5 m to 4 m, for example. Examples of commercially available disc filters include Ceramec CC filters, models CC-6, CC-15, CC-30, CC-45, CC-60, CC-96 and CC-144 manu- factured by Outotec Inc.

All the filter discs 16 can be preferably essentially similar in structure. Each filter disc 16 may be formed of a number of individual sector-shaped filter elements 3, called filter plates, which are mounted circumferentially in a radial planar plane around the central shaft 4 of the filter to form an essentially continuous and planar disc surface. The number of the filter plates may be 12 or 15, for example.

Operation of the disc filter apparatus 1 1 may be controlled by a filter control unit, such as a Programmable Logic Controller, PLC.

Function of disc filter apparatus has already described in back- ground part of this description.

According to an aspect, the filter apparatus 1 comprises an identification unit 5 arranged to store an identification code that is specific for a filter element 3.

The identification unit 5 may comprise a transmitter apparatus 6 for wireless communication of an identification signal comprising said identification code such that the identification code is readable or receivable by the receiver means 8 of a receiver apparatus 7.

The identification unit 5 is arranged in rotating part of the filter apparatus, i.e. in the filter 2.

In an embodiment, the identification unit 5 is arranged in the filter element 3. Just one identification unit 5 is shown in Figure 2 for sake of clarity, but it is clear that every filter element 3 comprises an identification unit of its own.

In an embodiment, the identification unit 5 is a RFID (Radio Frequency Identification) tag or transponder and the transmitter apparatus 6 is the antenna of said RFID tag. Thus the identification signal is a radio frequency signal, and the receiver apparatus 7 is a RFID reader device.

The RFID tag may be passive, semi-passive or active RFID tag. As an embodiment of RFID technology, NFC (Near Field Communication) equipment is used.

In an embodiment, the identification unit 5 is an optically readable identification unit and the receiver apparatus 7 comprises an optical reader, the identification signal being thus an optical signal. The optically readable identification unit may comprise e.g. a bar code, data matrix code or QR (Quick Response) code.

The receiver means 8 comprises an antenna 10 tuned to receive the identification signal send by the identification unit 5.

In embodiments using RFID technology, the antenna 10 is an RFID reader antenna, the type of which may be e.g. dipole antenna, circular polarization antenna, monostatic circular antenna or bistatic circular antenna.

In an embodiment, the filter apparatus 1 comprises one receiver apparatus 7 per one filter disc 16 such that each of the receiver apparatus 7 is arranged for receive the identification codes from the transmitter apparatuses 6 of one specific filter disc 16 only.

In another embodiment, the number of the receiver apparatuses 7, e.g. RFID readers, is lower than the number of the filter discs 16, i.e. identification codes from two or more filter discs 16 are read by a common receiver apparatus 7.

In an embodiment, the output signal is send to a database 22 that comprises identification information of all the filter elements 3 of the filter appa- ratus 1 . This embodiment is discussed more detailed later in this description.

In an embodiment, the receiver means 8 comprises an antenna 10 that is arranged in an antenna module 1 1 . The antenna module 1 1 comprises a frame 12 supporting the antenna 10 and a support structure 13 keeping the antenna 10 at a suitable distance from the filter 2.

The suitable distance may be selected so that the reading distance, i.e. the distance between the antenna 10 and the identification unit 5 to be read by said antenna 10 is in range of 1 cm - 3 m. In this range the reading of the identification signal can be realized precisely enough for various signalling technology, e.g. RFID, NFC, optical. The reading distance is preferably in range of 2 cm - 2 m. In this range a passive identification unit, e.g. a passive RFID unit, works well during the filtration process. The reading distance is more preferably 5 cm - 70 cm. In this range the reading of the identification signal can be realized optimally and errors in the readings minimized. Additionally, this range is especially suitable for passive RFID unit.

In the embodiment shown in Figures 1 and 2, the antenna module 1 1 is fixed in the filter apparatus 1 and comprises a tube like hollow profile 25 that is arranged parallel with the longitudinal axis X of the filter apparatus.

The antennas 10 are located above the filter discs 16 in a position 12 o'clock viewing along the longitudinal axis X in the direction where the rotation of the filter 2 takes place counterclockwise. In other words, an imaginary line L (dot-and-dash-line) crossing the antenna 10 and the longitudinal axis X makes 90° angle with horizontal level H when viewed along the longitudinal axis X in the direction where the rotation of the filter 2 takes place counterclockwise.

According to an aspect, the position of the antennas 10 may be se- lected between 9 o'clock and 16 o'clock (0° to 210°); this area or range of the filter 2 is usually free from solids or cake deposited onto the filter. The position of the antennas 10 is preferably between 1 1 o'clock - 15 o'clock (60° to 180°); this comprises good installation sites for the antennas without causing problems e.g. for maintenance work in a typical filter apparatus. The position of the antennas 10 is more preferably 1 1 o'clock - 14 o'clock (60° to 150°); in this range the exposure of the antennas 10 to dirt is minimized.

In Figure 2 there is shown also shown another line L' (dash-line) showing direction of 1 1 o'clock, i.e. 60°.

According to another embodiment, the receiver apparatus 7 is fixed in a support frame 26 separate from the frame 23 of the filter apparatus. One example of this embodiment is shown by dashed line in Figure 2. The support frame 26 may be e.g. a part of building structure covering the filter apparatus 1 or a purposively made support structure separate from the frame 23 of the filter apparatus.

Figure 3 is a perspective top view illustrating an exemplary antenna module, and Figure 4 is a cutaway view illustrating details of the antenna module shown in Figure 3.

The antenna module 1 1 may comprise tube like hollow profile 25 or support frame, the cross-section of which may be round (as shown in Figure 3), polygon (e.g. rectangle as shown in Figure 4) or any other suitable shape.

The material of the profile 25 may be any suitable material being permeable to the identification signal. For instance, plastic or plastic composition material can be used. Alternatively, impermeable material may be used if the profile 25 comprises openings or has a generally speaking open structure allowing the identification signal to reach the antenna 10.

The hollow profile 25 may constitute the frame 12 of the antenna module, or alternatively, the antenna module 1 1 may comprise a separate frame supporting e.g. the hollow profile 25, receiver apparatuses and their antennas 10 etc.

In an embodiment, the antenna module 1 1 comprises plurality of module elements 14 that are connected consecutively to each other by attachment means 15. The module element 14 may comprise one or more antennas 10.

Alternatively, the antenna module 1 1 comprises on-piece hollow profile 25 or support frame that extends over the whole antenna module 1 1 .

The receiver apparatus 7 may be arranged in the antenna module

1 1 , or alternatively, only the antenna 10 is arranged in the antenna module 1 1 whereas the receiver apparatus may be attached to the frame of the filter apparatus 23 or arranged in a cabin etc.

In an embodiment, the antenna module 1 1 comprises a distance ad- justing means 33 for adjusting the reading distance D. Thanks to the adjusting means 33, the reading distance D can be optimized for the current filtering process and/or the filter apparatus 1 . Furthermore, the antenna module 1 1 can be lifted higher away from the reading distance D and thus service work of the antenna module 1 1 etc. may be facilitated.

In the embodiment shown in Figure 3, the adjusting means 33 comprises a telescopic structure the length of which can be adjusted. Alternatively, the adjusting means 33 may be realized by e.g. hinges etc.

In an embodiment, the antenna module 1 1 comprises an alignment means 34 for adjusting the alignment or angle of the antenna module 1 1 - and thereby the angle of the antenna(s) 10 - relative to the identification unit 5. Thus the antenna(s) 10 can be set in a position where the receiving of the identification signal is optimized.

In the embodiment shown in Figure 3, the alignment means 34 comprises two abutting flanges, the mutual position of which can be changed by rotating at least one of said flanges.

According to an aspect, the antenna module 1 1 comprises at least one light element 21 arranged to lighten the filter disc(s) 16. The light element 21 may comprise e.g. a LED. Lighting of the filter disc(s) 16 promotes safety at work.

As discussed earlier, the filter apparatus 1 may comprise plurality of receiver apparatuses 7, e.g. one receiver apparatus per one filter disc 16. All the receiver apparatuses 7 may comprise a forwarding means 9 of its own. The forwarding means 9 is arranged to forward or send an output signal based on the identification data received from the identification units 5. The output signal comprises, at least, identification data of the filter element 3. The output signal is sent to the filter control unit 27, e.g. PLC, and/or to the database 22 as discussed later in this description.

In another embodiment, the identification codes from two or more receiver apparatuses 7 are supplied to one forwarding means 9 common for said multiple receiver apparatus 7. For instance, the apparatus may comprise just one forwarding means 9 arranged e.g. in the antenna module 1 1 . In an embodiment, each of the module elements 14 comprises the forwarding means 9 dedicated for the receiver apparatuses 7 arranged in said module element 14.

Figure 5 is a perspective top view illustrating an exemplary drum fil- ter apparatus.

The drum filter apparatus 1 comprises a filter drum 19, and the filter element 3 is a part of outer surface of said filter drum 19.

According to an aspect, the antenna module 1 1 is arranged to locate between a washing station 35 of the filter elements and the slurry basin 24 such that, in direction of rotation of the filter, the antenna module 1 1 follows the washing station 35 and the slurry basin 24 follows the antenna module 1 1 . Function of drum filter apparatus has already described in background part of this description.

Figures 6A and 6B illustrate exemplary filter elements of a disc filter apparatus.

The filter element 3 comprises a permeable membrane layer 17 made of a porous ceramic and a substrate 18 supporting said membrane layer 17. Alternatively, the membrane layer 17 comprises fibrous material or cloth.

An identification unit 5 described above is arranged in the filter element 3.

In embodiment shown in Figure 6A, the identification unit 5 is arranged on the peripheral outer edge surface 28 of the filter element. Thus the distance to the receiver apparatus 7 may be minimized.

The identification unit 5 may be secured to the filter element by adhesive, fastening elements e.g. screws etc. The identification unit 5 is protect- ed against harsh environment by sealing and/or encapsulation.

The filter element 3 may be provided with an indicator 20 arranged to generate a break indication upon breakage of the filter element 3. According to an aspect, the identification unit 5 is connected to the indicator 20 and arranged to transmit wirelessly a break signal based on the break indication to the receiver apparatus 7 and from there to the filter control unit 27.

According to another aspect, however, the identification unit 5 is not connected to the indicator 20 but the break signal is transmitted by other means (not shown) to the filter control unit 27.

The indicator 20 may be e.g. electrically conductive wiring. The conductive wiring creates a continuous circuit loop 29. If the conductive wiring breaks at any part of the filter element 3 also the circuit loop 29 gets broken or disconnected. The break of the circuit loop 29 will indicate the breakage of the filter element 3, generating thus a break indication.

The indicator 20 may have any wiring pattern that enables a desired detection of breakage in different parts of the filter element 3 but does not unnecessary disturb the filtering function of the element. In an embodiment, there are indicators 20 on both sides of the filter element 3, which indicators 20 are series-connected to form a single circuit loop.

In embodiment shown in Figure 6B, the identification unit 5 is ar- ranged close to mounting parts 30 which function as means for attaching the filter element 3 to mounting means in the central shaft of the filter apparatus. Figure 7 illustrates an exemplary method for controlling a filter apparatus. According to an aspect, the information about the filter elements 3 of the filter apparatus 1 is collected in a database 22. This information is based on identification codes stored in the identification units 5 and read by receiver ap- paratuses 7 of said filter apparatus 1 .

In an embodiment, the database 22 is arranged in the filter control unit 27. A wireless radio transmitter or other kind of wireless transmission medium may be employed to transfer signals from the receiver apparatuses 7 to the filter control unit 27. In another embodiment, a wire communication is em- ployed to transfer signals from the receiver apparatuses 7 to the filter control unit 27.

In another embodiment, the database 22' is arranged in a network server that is connected to the filter control unit 27 by wire or wirelessly, e.g. over Internet connection.

It is to be noted that there can be several filter apparatuses 1 situated in different production plants connected to the database 22, 22'.

Receiver apparatuses 7 read the identification units 5 in certain periods, e.g. once per revolution of the filter.

The database 22, 22' is updated automatically in case of change of one or more filter element(s) 3. In other words, the database 22, 22' is synchronized and the individual filter elements 3 are monitored online. This way the identity information of the filter elements 3 in the filter apparatus 1 is always known.

In another embodiment the database 22, 22' is synchronized offline, e.g. via USB stick.

The database 22, 22' may further include information about installation date and working hours of every filter elements 3. Thus old, soon to be changed filter elements 3 can be found and it is possible to forecast when new filter elements 3 should be purchased. Thus the number of the filter elements 3 kept in stock can be optimized and the maintenance planning of the filter apparatus 1 is easier. Furthermore, it is possible to find out trend lines of failure causes of the filter elements 3.

Figure 7 is also showing some process steps relating to the manufacturing of the filter elements 3 and taking place e.g. in filter element factory 32. The identification units 5 are RFID tags which are encoded, i.e. provided with an identification code, with a RFID printer 31 and attached to the filter el- ements 3. The identification code may be sent to the database 22, 22' directly from the filter element factory 32. by wire or wirelessly, e.g. over Internet connection.

The invention is not limited solely to the embodiments described above, but instead many variations are possible within the scope of the inventive concept defined by the claims below. Within the scope of the inventive concept the attributes of different embodiments and applications can be used in conjunction with or replace the attributes of another embodiment or application.

The drawings and the related description are only intended to illustrate the idea of the invention. The invention may vary in detail within the scope of the inventive idea defined in the following claims. According to an embodiment, for instance, the receiver apparatus 7 may be a hand-held device.

Reference symbols

1 filter apparatus

2 filter

3 filter element

4 central shaft

5 identification unit

6 transmitter apparatus

7 receiver apparatus

8 receiver means

9 forwarding means

10 antenna

1 1 antenna module

12 frame of the antenna module

13 support structure

14 module element

15 attachment means

16 filter disc

17 porous membrane layer

18 substrate

19 filter drum

20 indicator

21 light element

22, 22' database

23 frame of the filter apparatus

24 slurry basin

25 profile

26 support frame

27 filter control unit

28 peripheral outer edge surface

29 circuit loop

30 mounting parts

31 RFID printer

32 filter element factory

33 distance adjusting means

34 alignment means 35 washing station

D reading distance

H horizontal level

L, L' line

X longitudinal axis

Claims

1 . A filter apparatus, comprising a filter formed by a plurality of filter elements,

the filter arranged around a central shaft,

the central shaft and the filter being rotatable around longitudinal axis of the central shaft,

the filter apparatus further comprising

an identification unit arranged to store an identification code specific for the filter element,

a receiver apparatus comprising a receiver means arranged to receive wirelessly an identification signal comprising said identification code, and a forwarding means for forwarding an output signal based on said identification code,

the apparatus comprising two or more consecutive co-axial filter discs with sectors formed by a plurality of sector-shaped filter elements, and two or more receiver apparatuses, respectively, arranged for receiving the identification code from the transmitter apparatuses of one specific filter disc only, that

the receiver means comprises an antenna that is arranged in an an- tenna module, said antenna module comprising a frame supporting the antenna at a reading distance from the filter, and that

the antenna module is arranged to locate above the filter discs in a position between 9 o'clock and 16 o'clock, preferably between 1 1 o'clock - 15 o'clock, more preferably 1 1 o'clock - 14 o'clock viewing along the longitudinal axis where the rotation of the filter takes place counterclockwise.

2. The apparatus according to claim 1 , wherein the identification unit is a RFID tag and the receiver apparatus comprises a RFID receiver, the identification signal being thus a radio frequency signal.

3. The apparatus according to claim 1 , wherein the identification unit is an optically readable identification unit and the receiver apparatus comprises an optical reader, the identification signal being thus an optical signal.

4. The apparatus according to any one of the preceding claims, wherein the identification unit is arranged in the filter element.

5. The apparatus according to any one of the preceding claims, wherein the reading distance is selected in range of 1 cm - 3 m, preferably 2 cm - 2 m, more preferably 5 cm - 70 cm.

6. The apparatus according to any one of the preceding claims, wherein the antenna module comprises a distance adjusting means for adjusting the reading distance.

7. The apparatus according to any one of the preceding claims, wherein the antenna module comprises an alignment means for adjusting the alignment of the antenna module relative to the identification unit.

8. The apparatus according to any one of the preceding claims, wherein the receiver means is fixed in the filter apparatus.

9. The apparatus according to any one of claims 1 - 7, wherein the receiver means is fixed in a support structure separate from the frame of the filter apparatus.

10. The apparatus according to any one of the preceding claims, wherein the antenna module comprises module elements that are connected consecutively to each other by attachment means.

1 1 . The apparatus according to any one of the preceding claims, wherein the filter element comprises a porous membrane layer and a substrate supporting said membrane layer.

12. The apparatus according to claim 1 1 , wherein the porous membrane layer is made of ceramics.

13. The apparatus according to claim 1 1 , wherein the filter element comprises a permeable membrane layer comprising fibrous material and a substrate supporting said membrane layer.

14. The apparatus according to claim 13, wherein the permeable membrane layer is a fabric comprising monofilaments and/or multifilaments.

15. The apparatus according to any one of the preceding claims, wherein the identification codes from multiple receiver apparatus are supplied to the forwarding means common for said multiple receiver apparatus.

16. The apparatus according to any one of the preceding claims, wherein the filter element comprises an indicator arranged to generate a break indication upon breakage of said filter element, and wherein

the transmitter apparatus for wireless communication is arranged to communicate a break signal based on said break indication to the receiver apparatus.

17. The apparatus according to claim 16, wherein the wireless communication is based on RFID communication and the break signal is arranged to be received by the same antenna

as the identification signal of the corresponding filter element.

18. The apparatus according to any one of claims 5 - 17, wherein the antenna module comprises a light element arranged to lighten the filter.

19. The apparatus according to any one of claims 1 - 4, wherein the receiver apparatus is a hand-held device.

20. A method for controlling the filter apparatus claimed in claim 1 , the method comprising:

- updating automatically the database in case of change of one

or more filter element(s).

21 . A filter apparatus, comprising a filter formed by a plurality of filter elements,

the filter arranged around a central shaft,

the central shaft and the filter being rotatable around longitudinal ax- is of the central shaft,

the filter apparatus further comprising

a receiver apparatus comprising a receiver means arranged to receive wirelessly an identification signal comprising said identification code, and a forwarding means for forwarding an output signal based on said identification code.

22. The apparatus according to claim 21 , wherein the identification unit is a RFID tag and the receiver apparatus comprises a RFID receiver, the identification signal being thus a radio frequency signal.

23. The apparatus according to claim 21 , wherein the identification unit is an optically readable identification unit and the receiver apparatus comprises an optical reader, the identification signal being thus an optical signal.

24. The apparatus according to any one of claims 21 - 23, wherein the identification unit is arranged in the filter element.

25. The apparatus according to any one of claims 21 - 24, wherein the receiver means comprises an antenna that is arranged in an antenna module,

said antenna module comprising a frame supporting the antenna at a reading distance from the filter.

26. The apparatus according to claim 25, wherein the reading distance is selected in range of 1 cm - 3 m, preferably 2 cm - 2 m, more preferably 5 cm - 70 cm.

27. The apparatus according to any one of claims 25 - 26, wherein the antenna module comprises a distance adjusting means for adjusting the reading distance.

28. The apparatus according to any one of claims 25 - 27, wherein the antenna module comprises an alignment means for adjusting the alignment of the antenna module relative to the identification unit.

29. The apparatus according to any one of the preceding claims, wherein the receiver means is fixed in the filter apparatus.

30. The apparatus according to any one of claims 25 - 28, wherein the receiver means is fixed in a support structure separate from the filter apparatus.

31 . The apparatus according to any one of claims 25 - 30, wherein the antenna module comprises module elements that are connected consecutively to each other by attachment means.

32. The apparatus according to any one of claims 21 - 31 , compris- ing two or more consecutive co-axial filter discs with sectors formed by a plurality of sector-shaped filter elements, and

two or more one receiver apparatus, respectively, arranged for receiving the identification code from the transmitter apparatuses of one specific filter disc only.

33. The apparatus according to claim 32, wherein the antenna module is arranged to locate above the filter discs in a position between 9 o'clock and 16 o'clock, preferably between 1 1 o'clock - 15 o'clock, more preferably 1 1 o'clock - 14 o'clock viewing along the longitudinal axis where the rotation of the filter takes place counterclockwise.

34. The apparatus according to claim 32 or 33, wherein the filter element comprises a porous membrane layer and a substrate supporting said membrane layer.

35. The apparatus according to claim 34, wherein the porous membrane layer is made of ceramics.

36. The apparatus according to claim 32 or 33, wherein the filter el- ement comprises a permeable membrane layer comprising fibrous material and a substrate supporting said membrane layer.

37. The apparatus according to claim 36, wherein the permeable membrane layer is a fabric comprising monofilaments and/or multifilaments.

38. The apparatus according to any one of claims 21 - 31 , wherein the filter apparatus comprises a filter drum, wherein the filter element is a part of outer surface of the filter drum.

39. The apparatus according to claim 38, comprising a washing sta- tion and a slurry basin, wherein the antenna module is arranged to locate between said washing station and slurry basin such that, in direction of rotation of the filter, the antenna module follows the washing station and the slurry basin follows the antenna module.

40. The apparatus according to any one of claims 21 - 39, wherein the identification codes from multiple receiver apparatus are supplied to the forwarding means common for said multiple receiver apparatus.

41 . The apparatus according to any one of claims 21 - 40, wherein the filter element comprises an indicator arranged to generate a break indication upon breakage of said filter element, and wherein

42. The apparatus according to claim 41 , wherein the wireless communication is based on RFID communication and the break signal is arranged to be received by the same antenna as the identification signal of the corresponding filter element.

43. The apparatus according to any one of claims 25 - 42, wherein the antenna module comprises a light element arranged to lighten the filter.

44. The apparatus according to any one of claims 21 - 24, wherein the receiver apparatus is a hand-held device.

45. A method for controlling the filter apparatus claimed in claim 21 , the method comprising:

- updating automatically the database in case of change of one or more filter element(s).