GB2303082A

GB2303082A - Filter with electronically readable label

Info

Publication number: GB2303082A
Application number: GB9614405A
Authority: GB
Inventors: Roger Edward Page; George B Peacock
Original assignee: Pall Corp
Current assignee: Pall Corp
Priority date: 1995-07-11
Filing date: 1996-07-09
Publication date: 1997-02-12
Also published as: CA2180488A1; FR2736560A1; JPH0924209A; DE19627595A1; GB9614405D0

Description

1 FILTERS 2303082 The invention relates to filters.

Filters are in the majority of cases designed for specific applications. For example, there are filters designed for use in specific medical applications such as blood filters or heat and moisture exchange filters and there are filters designed for specific industrial applications such as the filtration of lubricants or the filtration of drinks. In all cases, it is important that the correct filter is used for a particular application. In some cases, filters can be used side-by-side that look very similar but which have different characteristics. Although the filters may be packaged in packaging that gives information regarding the characteristics is of the associated filter, once the filters are unpackaged, it can be difficult to know whether a filter is being used that is appropriate for the desired application.

It has previously been proposed to provide filter assemblies including a filter cartridge within a housing, where the housing includes a sensor which monitors filter performance. For example, in US-A-4626344 the housing carries a sensor for sensing when engine oil has become restricted and requires replacement. US-A-4006083 has a switch in the housing for is 2 determining when the f ilter cartridge is clogged. US-A4578186 has a pressure sensitive switch in a filter inlet port of the housing to determine an increase in pressure. GB-A983750 discloses a fuel injection system including a filter cartridge and a switch in an inlet passageway of the housing to detect clogging. US-A-5061364 discloses a component surrounding a filter cartridge and producing an alternating electromagnetic field across the filter cartridge. An eddy current detector detects changes in the field caused by particles on the filter cartridge. US-A-3936284 discloses indicators mounted on the housing to monitor changes in pressure in inlet and outlet chambers of the housing. US-A5192424 discloses a filter cartridge carrying a tag bearing an identification mark.

According to a first aspect of the invention, there is provided a filter comprising a filter cartridge including a memory device containing a string of electronically readable information.

In one aspect, this string of information can be information regarding the characteristics of the filter so that it can be determined electronically whether, for example, the correct filter is being used for a particular application.

In addition, filters are designed to operate in particular is 3 environments and are designed not to last for an infinite time. If the environment changes or a filter reaches a state in which it no longer functions effectively, the filter will need to be removed and replaced. In general, this is determined by monitoring the operating conditions of the filter and by looking at the pressure drop across the filter. This, however, can only give an approximate indication of the operating conditions of the filter.

Preferably, therefore, the memory device is associated with an input device, said input device feeding to the memory a string of information that can be read electronically from the memory.

The input device can determine when, for example, the filter is operating at a temperature range for which it is not designed and/or can determine when the filter is becoming clogged. Reading the information in the memory can therefore allow the filter to be changed at an appropriate time.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a cross-section of a filter cartridge Figure 2 is a schematic view of a first memory device for use with the cartridge of Figure 1, is 4 Figure 3 is a schematic view of a second memory device for use with the cartridge of Figure 1.

Referring to Figure 1, the filter cartridge comprises a filter medium 10 of a polymeric material provided with two end caps 11. Each end cap 11 is formed from a plastics material. One end cap 11 receives one of the ends of the polymeric filter medium 10 and the other end cap 11 receives the other of the ends of the filter medium 10. The end caps 11 allow the filter cartridge to be mounted in a housing (not shown).

One end cap 11 incorporates a memory device 12 containing a string of electronically readable information.

In one embodiment, shown in Figure 2, the memory 12 is an electronic readonly memory containing information regarding the characteristics of the filter. These could be the physical dimensions of the filter and/or its rating and/or other information such as a reference number, manufacturer's details, operating temperature limits, safety information or operating instructions. The memory is associated with a transmitter or transponder 13 that transmits this string of information to an appropriate reader on receipt of an interrogation signal from the reader.

Alternatively, the memory 12 may be associated with an output device to allow physical electrical connection between the reader and the memory. The connection may be a permanent hard wired connection. Alternatively, the memory could be provided with a cover that may be removed to allow electrical connection between the reader and the memory. Another possibility is for the cover to be pierceable by a suitable connector to allow electrical connection between the connector and the memory.

In an alternative arrangement shown in Figure 3, the memory 12 is associated with an input device in the f orm of an electrical monitor 14 for feeding to the memory 12 a string of electronic information that can be read electronically from the memory. For example, the electrical monitor 14 could detect blockage of the filter element 10 or could monitor temperature or pressure or any other desired variable parameter relating to the filter.

A further possibility is the inclusion of an electrical sensor that detects particular biochemicals, such as enzymes, proteins, antibodies, antigens, bacteria, viruses and produces a string of electrical information related to said bio- chemicals. This information may be used to identify the presence of a particular biochemical or biochemicals and/or as an integrity measurement and/or to control the feed of fluid to the filter or to control the effluent from the filter. The 6 electronic memory 12 could simply receive a string of electrical information from such a monitor 14 or sensor or receive this information and include fixed information regarding the filter 10 of the kind described above with reference to Figure 1. Another possibility is the inclusion of an electronic computer 17 for processing electronic data from the monitor 14 and storing the output data in the memory 12.

This information may be output by an electrical transmitter 13 as described above or by an electrical output device 15 which makes physical engagement with an input device 16 of a reader in any of the ways described above with reference to Figure 2.

The memory 12 could be programmed to transmit an electronic warning signal when a particular detected parameter exceeds a predetermined limit.

In any of the embodiments described above with reference to the drawings, the memory 12 and its associated components (including the computer 17, where provided) may be formed on a single electronic chip. Alternatively, the memory 12 could be written to remotely from remote sensors or from a manually operated input device. A manually operated input device could, f or example, be used to input to the memory 12 an 7 electronic signal corresponding to the number of cycles experienced by the filter 10. The memory 12 may be associated with its own power source, such as a battery.

In general, of course, the information will be stored in binary form as a string of bits of information. Preferably this will be more than 100 bits of information and more preferably more than 1000 bits of information.

Any of the memory devices described above could be used with filter cartridges other than the cartridge shown in Figure 1 with the filter medium and the end caps being of any suitable material. In addition, the memory device could be incorporated in a part of the cartridge other than in an end cap 11. It could be incorporated in the filter medium. The final output need not be electronic; the electronically is readable information could be converted into speech.

Claims

8 CLAIMS

1 A filter comprising a filter cartridge including a memory device containing a string of electronically readable information.

2. A filter according to claim 1 wherein the memory device is a read-only memory.

3. A filter according to claim 1 wherein said memory device is associated with an input device, said input device feeding to the memory device a string of information readable electronically from the memory device.

4. A filter according to claim 3 wherein the input device is a monitoring means for feeding to the memory device information regarding a variable parameter monitored by the monitoring means.

5. A filter according to any one of claims 1 to 4 wherein the memory device includes a transmitter for transmitting an electrical signal including said string of information.

6. A filter according to any one of claims 1 to 5 wherein the memory device includes an output connection for connection to a reader for reading the string of information in the memory device.

7. A filter substantially as hereinbefore described with reference to Figures 1 and 2 or to Figures I and 3 of the accompanying drawings.