CN111315465A

CN111315465A - Filter cartridge with conductive band

Info

Publication number: CN111315465A
Application number: CN201880051963.0A
Authority: CN
Inventors: 乔治·吉龙迪
Original assignee: UFI Innovation Center SRL
Current assignee: UFI Innovation Center SRL
Priority date: 2017-06-23
Filing date: 2018-06-21
Publication date: 2020-06-19
Also published as: EP3641908A1; IT201700070458A1; WO2018235030A1

Abstract

A filter cartridge (1) of a fluid filter assembly may be housed in a filter body of the filter assembly. The filter cartridge (1) comprises a filter body (2) having a tubular shape extending axially along a main axis (X-X). The filtering main body (2) comprises an inner filtering cylinder (20), a heating layer (21) and an outer filtering cylinder (22). The heating layer (21) comprises a first annular means (211) and a second annular means (212) accessible by an external power source and positioned adjacent to the axial ends of the filter cartridge (1). Furthermore, the heating layer (21) comprises an electrically conductive band (210) extending around a main axis (X-X) extending between the first annular arrangement (211) and the second annular arrangement (212).

Description

Filter cartridge with conductive band

Technical Field

The present invention relates to a filter cartridge for a fluid filter assembly and a method of producing the filter cartridge.

The invention is particularly applicable to automotive films (films). In particular, the present invention falls within the context of a fluid filter assembly whose viscosity can be affected by the operating temperature. For example, filter assemblies are preferably known which are suitable for filtering fuel, preferably of the diesel type, to separate the fuel from the suspended particles and from the moisture-containing particles. Furthermore, in the automotive industry, filter assemblies are known which are suitable for filtering blow-by gases, oil, urea or air.

The main problem of fluid filtration is the accumulation of impurities, more or less accidentally, on the first layer of the filtering body crossed by the fluid.

Obviously, the accumulation of said impurities causes clogging of the filtering body, which affects its operation.

When the fluid is at low temperature (for example, when the engine is started, or in particularly severe weather conditions) and contains a large number of crystals: for example, paraffin crystals are present in diesel fuel; the presence of ice crystals in aqueous based fluids (such as urea); this is particularly felt when droplets, crystals of condensate are present in the gaseous fluid (such as blow-by gas or outside air).

To overcome this problem, in the prior art it is known to heat the fuel (or more specifically the working fluid) to reduce or avoid the accumulation of paraffin crystals or, generally, ice crystals.

In fact, a solution is provided for a filtering assembly in which the filtering body comprises a heating layer, preferably electrically conductive, the temperature of which can be electrically controlled, if necessary, to dissolve the crystals and prevent the above-mentioned clogging.

The main problem affecting these filter cartridge solutions is to carry the power supply to the heating layer.

Typically, this requires design and production involving filter cartridges having specific complex geometries. For example, filter cartridges are known which have a specific conductive cage surrounding the filter body, which conductive cage is provided on at least one endplate with electrical contacts adapted to be placed in contact with the power supply means.

The more complex the geometry of the cartridge and its components, the more complex the corresponding production operations.

An example of an embodiment of a filtering assembly presenting such a drawback is shown in document EP 2811147.

Solution of the invention

There is therefore a strongly felt need to provide a filter cartridge with an electrically heatable layer, in particular with a simple geometry and with little complexity in production.

Therefore, there is also a strongly felt need to have a filter cartridge comprising a heating layer that can be produced by means of a simple and efficient production method.

It is an object of the present invention to provide a filter cartridge and a method of producing the filter cartridge that meets the above-mentioned needs and also meets the needs of a particular application field effectively and efficiently.

This object is achieved by a filter cartridge as claimed in claim 1 and a method of producing a filter cartridge according to claim 9. The dependent claims describe preferred embodiment variants relating to further advantageous aspects.

Drawings

Further, the characteristics and advantages of the invention will become apparent from the following description of preferred exemplary embodiments of the invention, provided by way of non-limiting example only with reference to the accompanying drawings, in which:

from fig. 1a to 1g, various steps of a method of producing a filter cartridge, object of the present invention, are illustrated according to a preferred embodiment; specifically, fig. 1g illustrates a perspective view of a filter cartridge in accordance with a preferred embodiment;

fig. 2 shows a perspective view of some components of the filter cartridge as shown in fig. 1g, in particular, the inner filter cylinder and the heating layer according to a preferred embodiment;

figures 3b and 3a show a front view and a longitudinal section respectively of a filtering body comprised in a filtering cartridge according to a preferred embodiment of the present invention;

fig. 4 shows an enlarged view of a heating band comprised in a heating layer according to a preferred embodiment of the invention.

Detailed Description

In the drawings, reference numeral 1 denotes a filter cartridge according to an embodiment of the present invention.

In particular, the filter cartridge 1 is in particular for a fluid filter assembly; preferably, the fluid to be filtered is a fuel, preferably diesel. In a further embodiment variant, the filter cartridge 1 is in particular for a fluid filter assembly in which the fluid is urea, oil, air, blow-by gas or the like.

According to the invention, the filter cartridge 1 of the invention is housed in a filtering body of the filtering assembly that defines a dedicated filtering chamber.

The filter cartridge 1 extends along a main axis X-X.

The filter cartridge 1 comprises a filter body 2 having a tubular shape extending axially along a main axis X-X.

In fact, said filtering body 2 can be crossed in a radial direction by a fluid: the preferred embodiment of the invention, such as shown in the drawings, is from the outside in, and in variations of the embodiment of the invention, from the inside out.

According to the invention, the filtering body 2 comprises, in its radial extension, an inner filtering cylinder 20, a heating layer 21 and an outer filtering cylinder 22. In particular, in the present disclosure, reference is made to a filter cylinder to refer to a filter device having a generally cylindrical, tubular shape.

In other words, the filtering body 2 has three separate parts formed concentrically with each other about the axis X-X. Preferably, heating layer 21 is thus sandwiched between inner filter cylinder 20 and outer filter cylinder 22. That is, heating layer 21 is sandwiched between two filter media.

According to a preferred embodiment, said inner filtering cylinder 20 comprises a non-woven fabric of synthetic fibres or glass fibres or synthetic fibres mixed with cellulose and/or viscose fibres and/or regenerated viscose fibres.

According to a preferred embodiment, the inner filtering cylinder 20 has depth partitions (depth partitions) comprising a non-woven fabric of synthetic fibres.

According to a further preferred embodiment of the invention, the inner filtering cylinder 20 comprises a plurality of stacked filtering layers. Preferably, the stacked filter layers exhibit different physical characteristics.

According to a preferred embodiment, said outer filtering cylinder 22 comprises a non-woven fabric of synthetic fibres or glass fibres or synthetic fibres mixed with cellulose and/or viscose fibres and/or regenerated viscose fibres.

According to a further preferred embodiment of the invention, the outer filter cylinder 22 comprises a plurality of stacked filter layers. Preferably, the stacked filter layers exhibit different physical characteristics.

The object of the solution of the present invention can be achieved independently of the thickness of the inner 20 and outer 22 filtering cylinders.

According to a preferred embodiment, the heating layer 21 comprises a first ring 211 and a second ring 212 which are electrically conductive and accessible by means of an external power source (not shown) provided, for example, on the filtering body.

Furthermore, the heating layer 21 comprises an electrically conductive band 210 extending between the first ring 211 and the second ring 212 to place them in electrical contact with each other.

According to a preferred embodiment, the filter cartridge 1 has, near its axial ends, said first annular means 211 and said second annular means 212, and the electrical connection between said two parts is ensured by means of an electrically conductive band 210.

According to a preferred embodiment, each ring-shaped device comprises

contact pins

2115, 2125 extending in a radial direction so as to protrude from the filter body 2 in such a way as to be contactable with an external power supply, for example provided on the filter body in which the filter cartridge 1 is housed. Therefore, preferably, each

contact pin

2115, 2125 passes through the outer filter cylinder 22 or the inner filter cylinder 20 until protruding therefrom.

According to a preferred embodiment, the conductive band 210 extends over the length of the wrap around the inner filtering cylinder 20.

According to a preferred embodiment, the conductive strips 210 extend in a helical direction around the main axis X-X.

Preferably, the conductive strip 210 comprises a plurality of conductive filaments (filaments) supported by spacer elements configured as a mesh or a woven or non-woven fabric adapted to form a series of gaps H between the conductive filaments constituting the conductive strip. The presence of this spacer allows to maintain a uniform distance between the conductive filaments wound around the axis X-X of the filter element and to facilitate the handling of the strip during the assembly sequence of the filter element.

Preferably, the conductive filaments are made of a conductive material having a suitable conductivity for the purpose of electrical conduction, such as, for example, stainless steel or aluminum or a metal alloy.

According to a preferred embodiment, the conductive filaments are made of a PTC (positive temperature coefficient) metal alloy. Preferably, the metal alloy is a nickel alloy.

That is, the conductive band 210, in turn, is allowed to be traversed by a fluid to have a conductive portion that changes its temperature upon an electrical command.

According to the invention, the conductive strip is characterized by a width L determined by the value of the gap H and by the diameter of the conductive filaments. The value of H may be less than 5mm, typically between 1mm and 4 mm.

According to the object of the present invention, the conductive strip 210 covers the inner filtering cylinder 20 in a certain percentage, according to the characteristics of the conductive strip 210 itself and also according to the characteristics of the inner filtering cylinder 20 and/or of the outer filtering cylinder 22.

In fact, preferably, the geometrical characteristics of the filaments (number, diameter, length) and the electrical characteristics of the material used for said filaments (electrical resistance) determine the thermal power of the system, while the value of the spacing H determines the percentage of the filtering surface covered by said band and, therefore, the distribution of the thermal power on the filter surface. The type of distribution affects the maximum temperature reached on the outer surface of the filter media and therefore the efficiency of the heating system.

In other words, portions of the inner filter cylinder 20 will be in contact with corresponding portions of the outer filter cylinder 22. Meanwhile, the heating belt 210 is disposed between the inner filter cylinder 20 and the outer filter cylinder 22, if present.

According to a preferred embodiment of the present invention, first ring-shaped means 211 and second ring-shaped means 212 each comprise an inner ring 211 ', 212' and an outer ring 211 ", 212", wherein a conductive band 210 is positioned between them.

Thus, preferably, the inner rings 211 ', 212', the conductive band 210 and the outer rings 211 ", 212" are positioned in a radial direction, or vice versa. Preferably, the inner rings 211 ', 212' are located on the inner cylinder 20, while the outer rings 211 ", 212" are located on the outer cylinder 22.

According to a preferred embodiment, the inner rings 211 ', 212' serve as a support and the outer rings 211 ", 212" are electrically contactable with a power supply by means of

respective contact pins

2115, 2125. Thus, in a preferred embodiment, the inner rings 211 ', 212' are non-conductive.

According to a further embodiment, both the inner rings 211 ', 212' and the outer rings 211 ", 212" are electrically conductive.

A preferred embodiment of the filter cartridge 1, object of the present invention, further comprises a first end plate 31 and a second end plate 32 placed at the ends of the filter body.

One object of the present invention is also a method of producing a filter cartridge for a fluid filter assembly having the above characteristics.

The production method comprises the following steps:

-producing an inner tubular element 200 extending along a main axis X-X;

-winding the conductive band 210 on the inner tubular filter element 200;

arranging a plurality of pairs of

ring devices

211 and 212, each pair comprising a first ring device 211 and a second ring device 212, wherein each pair of

ring devices

211, 212 is axially spaced from the next pair along main axis X-X, wherein each

ring device

211, 212 comprises a

2125, 2125 extending radially with respect to main axis X-X;

-producing the outer tubular element 220, thus obtaining a tubular filtering body;

cutting said tubular filtering body obtained in a radial direction with respect to the main axis X-X between the first annular means 211 and the second annular means 212, thus obtaining a plurality of filtering bodies 2 similar to those described above.

According to a preferred embodiment, in said step of the method in which the pairs of

annular devices

211, 212 are arranged with respect to the consecutive two pairs, the first axial distance D-D is defined as the distance between the two inner annular devices (facing each other) and the second axial distance D-D is defined as the distance between the two outer annular devices (i.e. those arranged respectively furthest apart).

Thus, preferably, the tubular filter body is radially segmented by defining an end of the tubular filter body at an axial segment distance a-a; in particular, the tubular filtering body is radially segmented between two annular devices belonging to the same pair of annular devices. That is, the tubular filter body is radially segmented in a spacing that exists between a first axial distance D-D and a second axial distance D-D.

According to a preferred embodiment, the production method comprises the following steps:

positioning the first end plate 31 and the second end plate 32 on each filtering body, joining all preferably by infrared welding, thus obtaining a complete filtering cartridge 1.

Preferably, said first and

second end plates

31, 32 are placed at the axial ends of each filtering body; i.e. the first end plate 31 and the second end plate 32 are located at an axial section distance a-a therebetween.

According to a preferred embodiment, in the production method, the step of arranging a plurality of pairs of

annular devices

211, 212 comprises, for each annular device, the steps of:

-arranging the inner rings 211 ', 212' on the inner tubular filter element 200;

arranging the outer rings 211 ", 212" at the first inner rings 211 ', 212'.

In particular, the step of winding the conductive band 210 on the inner tubular filter element 200 and on the inner rings 211 ', 212' arranged thereon is carried out between the two steps described above.

Furthermore, according to a preferred embodiment of the production method and of the filter cartridge product 1 itself, the conductive band 210 is wound helically around the inner tubular filter element 200, with an actual pitch equal to the distance between the two pairs of annular means 211, 212.

The above-described filter cartridge and method of producing a filter cartridge are innovative and fully meet the objects of the present invention which overcome the typical disadvantages of the prior art.

In fact, advantageously, the filter cartridge has a simple and effective geometry. In particular, the filter cartridge advantageously has a heating layer which is supplied with power in a simple power supply mode.

Advantageously, the filter cartridge has a plurality of radial layers having different physical characteristics to provide different filtration modes. Advantageously, the radial layers are different cylinders. Advantageously, the same cylinders with specific radial layers therein have different physical characteristics.

Furthermore, advantageously, the heating band remains in place, since it is sandwiched between the two filtering cylinders.

Advantageously, the filter cartridge includes a heating layer located within the filter body, thus eliminating the need for a specific heating element, cage or sleeve surrounding the filter media.

Innovatively, the production method provides simple operations that are reproducible over time.

Advantageously, by applying the production method, a plurality of filter cartridges is obtained simultaneously.

It is clear that a person skilled in the art may make modifications to the filter cartridge or to the production method to satisfy contingent needs, all falling within the scope of protection defined by the following claims.

List of reference numerals:

1 Filter cartridge

X-X principal axis

2 Filter body

2' central cavity

20 internal filtering cylinder

200 inner tubular filter element

21 heating layer

210 conducting strip

22 external filtering cylinder

220 outer tubular filter element

211 first ring device

211' first inner ring

211' first outer ring

2115 first contact pin

212 second ring device

212' second inner ring

212 "second outer ring

2125 second contact pin

31 first end plate

32 second end plate

Gap of H conductive band

Width of L conductive band

d-d first axial distance

Second axial distance D-D

Distance of A-A axial section

Claims

1. A filter cartridge (1) of a fluid filter assembly, which can be housed in a filter body of the fluid filter assembly, wherein the filter cartridge (1) extends along a main axis (X-X) and comprises a filter body (2) of tubular form extending axially along the main axis (X-X), which is traversable by a fluid in a radial direction, wherein the filter body (2) comprises, in its radial extension:

i) an inner filtering cylinder (20);

ii) a heating layer (21);

iii) an outer filter cylinder (22);

wherein the heating layer (21) comprises:

-a first ring device (211) and a second ring device (212), both electrically conductive and positioned adjacent to the axial ends of the filter cartridge (1), wherein each ring device comprises contact pins (2115, 2125) extending in a radial direction to protrude from the filter body (2) so as to be contactable by an external power supply, for example present on the filter body;

-a conductive strip (210) extending in length around said main axis (X-X) between said first ring means (211) and said second ring means (212) in such a way as to make mutual electrical contact therebetween.

2. The filter cartridge (1) of claim 1, wherein the conductive strip (210) is wound around the inner filter cylinder (20).

3. The filter cartridge (1) of claim 2, wherein the conductive strip (210) is helically wound around the main axis (X-X).

4. The filter cartridge (1) of any one of the preceding claims, wherein the conductive strip (210) comprises a plurality of conductive filaments supported by spacer elements.

5. The filter cartridge (1) of any one of the preceding claims, wherein the first and second ring-shaped means (211, 212) each comprise an inner ring (211 ', 212') and an outer ring (211 ", 212"), wherein the conductive strips are positioned between them.

6. The filter cartridge (1) according to claim 5, wherein the inner rings (211 ', 212') are for support and the outer rings (211 ", 212") are electrically contactable with the power supply by means of respective contact pins (2115, 2125).

7. The filter cartridge (1) of claim 6, wherein the inner ring (211 ', 212') and the outer ring (211 ", 212") are electrically conductive.

8. The filter cartridge (1) according to any one of the preceding claims, additionally comprising a first endplate (31) and a second endplate (32) positioned at the ends of the filter body (2).

9. A method for producing a filter cartridge for a fluid filter assembly, comprising the steps of:

-producing an inner tubular filtering member (200) extending along a main axis (X-X);

-winding a conductive strip (210) on said inner tubular filtering member (200);

-arranging a plurality of pairs of ring devices (211, 212), each pair comprising a first ring device (211) and a second ring device (212), wherein each pair of said ring devices (211, 212) is axially spaced from the next pair along said main axis (X-X), wherein each ring device (211, 212) comprises a pin (2125 ) extending radially with respect to said main axis (X-X);

-producing an outer tubular filtering member (220) to obtain a tubular filtering body;

-segmenting the obtained tubular filtering body in a radial direction with respect to the main axis (X-X) between the first annular means (211) and the second annular means (212), so as to obtain a plurality of filtering bodies (2).

10. The method for producing a filter cartridge according to claim 9, comprising the steps of:

-positioning a first end plate (31) and a second end plate (32) on each filter body, all joined preferably by means of infrared welding.

11. Method for producing a filter cartridge according to claim 9 or 10, wherein the step of arranging a plurality of pairs of annular means (211, 212) comprises, for each annular means, the steps of:

-arranging an inner ring (211 ', 212') on the inner tubular filter member (200);

-arranging an outer ring (211 ", 212") in correspondence of said first inner ring (211 ', 212');

wherein the step of winding said conductive strips (210) on said inner tubular filtering member (200) and on said inner rings (211 ', 212') arranged thereon is performed between the above steps.

12. A method for producing a filtering cartridge according to any one of claims 9 to 11, wherein the conductive strips (210) are spirally wound around the inner tubular filtering member (200), with an actual pitch equal to the distance between the two pairs of annular means (211, 212).