CN112237770B

CN112237770B - Filter cartridge with compensation device

Info

Publication number: CN112237770B
Application number: CN201910642168.5A
Authority: CN
Inventors: 乔基奥·基隆迪
Original assignee: Shanghai Sofima Automobile Filter Co ltd
Current assignee: Shanghai Sofima Automobile Filter Co ltd
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2024-01-05
Anticipated expiration: 2039-07-16
Also published as: CN112237770A

Abstract

A filter cartridge (1) of a filter assembly for a fluid (10) extending along a filter axis (X-X), comprising: a tubular filter medium (2) comprising a central cavity (20) through which a fluid can pass in a radial direction through the filter medium (2); a first plate (3) and a second plate (4) comprising a first through hole (30) and a second through hole (40) respectively defined by a first edge (31) and a second edge (41); a compensating device (5) of variable shape and/or position to change the volume of the flow portion through which the aqueous fluid flows, the change in shape and/or position being due to crystallization of the fluid. The compensation device (5) comprises: a filling element (6) at least partially housed in the central cavity (20), comprising a first end (61) and a second end (62); an annular gasket member (7) is elastically yieldable and includes an outer gasket edge (71) sealingly engaging the first plate (3) and an inner gasket edge (72) sealingly engaging the first end (61).

Description

Filter cartridge with compensation device

Technical Field

The present invention relates to a filter cartridge for a fluid filtration assembly. The invention further relates to a filter body of a fluid filter assembly, which is adapted to receive a filter cartridge. In addition, the invention relates to the filter assembly as a whole.

Background

The invention is preferably used in the automotive field. In particular, the present disclosure is actually a filter assembly for fluids, such as water or urea, that may cause crystallization risks (for use with vehicles in low temperature environments). In particular, water is understood to be a broad fluid which is wholly or partly water-containing.

In particular, the main problems plaguing this type of device relate to the following possibilities: when subjected to low temperatures, the fluid freezes or crystallizes (hereinafter, freezing and crystallization are collectively referred to as crystallization), resulting in an increase in volume in the fluid flow region and resulting in blockage of the fluid flow region. Clearly, depending on the type of fluid, there is a variation in the (crystalline) threshold temperature: for example, for pure water, the threshold temperature is 0 ℃, whereas for urea, the threshold temperature is-11 ℃.

In particular, the increase in volume can result in tension and deformation on the filter cartridge and/or corresponding components of the filter assembly.

In addition, in particular, it is undesirable to have a large amount of water on the clean side of the filter. Under given environmental conditions, this water may crystallize, blocking the flow at the output.

In addition, it is undesirable to have a large number of freely accessible "free" volumes that are suitable for containing the filtered fluid and thus result in an increase in the amount of stress transferred to the cartridge and filter body after the aqueous fluid is frozen.

For the above reasons, solutions for filter assemblies comprising respective filling and compensating members and/or portions are known, i.e. first of all, these members and/or portions are adapted to occupy the space of the filter assembly to limit the amount of water inside the filter assembly; second, since they are deformable, they are adapted to allow the available volume of space to be used by the fluid flowing into the filter assembly, if desired. Note that "deformable" refers to a component that undergoes a change in shape and/or position depending on the state of the fluid (i.e., liquid or solid).

The known solutions have particularly complex shapes and geometries, which complicate the production and assembly phases of the filter cartridge and/or the filter assembly.

Furthermore, it has been demonstrated that the periodic nature of the deformation of the components and/or of the filling and compensating portions affects their lifetime. Over time, the components and/or the filling and compensating parts lose their deformability and in some cases even break.

Disclosure of Invention

Accordingly, there is a need to provide a filter cartridge for a filter assembly and a filter assembly for fluids including the filter cartridge that overcomes these problems while at the same time fully addressing the needs of the art.

The object of the present invention is to provide a filter cartridge, a filter body adapted to accommodate the filter cartridge and a filter assembly which propose a simple, effective and durable compensating device which solves the significant problems of the prior art solutions.

One aspect of the present invention provides a filter cartridge for a filter assembly for filtering fluids at risk of crystallization. The filter assembly includes a filter body including a filter chamber defined by a body wall, wherein the filter cartridge is received in the filter chamber and extends along a filter axis. The filter cartridge includes: a tubular filter medium extending axially about the filter axis, the filter medium comprising a central cavity, wherein fluid is able to pass through the filter medium in a radial direction; first and second plates at ends of the filter media adapted to sealingly engage the body wall, the first and second plates including first and second through-holes, respectively, defined by first and second edges, respectively, at the filter axis; a shape and/or position variable compensation device for varying the volume of a flow portion through which an aqueous fluid flows, wherein the change in shape and/or position is caused by crystallization of the fluid, wherein the compensation device comprises: a) A filler element at least partially received in the central cavity, extending in length along the filter axis, the filler element including a first end and a second end; b) An annular gasket member elastically yieldable to permit axial movement of the filler member based on the formation of crystallized crystals, wherein the annular gasket member includes an outer gasket edge sealingly engaging the first plate and an inner gasket edge sealingly engaging the first end.

Another aspect of the invention provides a filter body for a filter assembly for filtering fluids at risk of crystallization. The filter assembly comprises a filter cartridge according to the preceding aspect, wherein the filter body comprises a cup and a lid closing the cup, the cup and the lid being mutually screwable to define a filter chamber delimited by a body wall, wherein the filter chamber is capable of receiving the filter cartridge.

The above object is achieved by the filter cartridge and the filter body according to the above aspects. In addition, the above object is also achieved by a filter assembly comprising the filter cartridge and the filter body of the above aspect. Preferred embodiments relating to further advantageous aspects are shown below.

Drawings

Further characteristics and advantages of the invention will in any case become apparent from the description given below of a preferred embodiment, which is formed by way of non-limiting example in connection with the accompanying drawings. Wherein:

FIG. 1 shows a longitudinal cross-sectional view of a filter assembly of the present invention according to a preferred embodiment;

FIG. 1a shows an enlarged portion of the filter assembly shown in FIG. 1;

FIG. 2 illustrates a longitudinal cross-sectional view of the filter assembly shown in FIG. 1, separated from the components;

fig. 3 shows a longitudinal section through a filter cartridge according to the invention with parts separated.

Reference numerals illustrate:

1a filter cartridge; 2 a filter medium; 20 a central cavity; 3 a first plate; 30 a first through hole; 31 a first edge; a 35 annular retainer ring; 350 a receiving area; 351 a compensation zone; 36 an outer annular groove; 38 axial locking teeth; 39 a first radial washer; 4 a second plate; 40 second through holes; 41 a second edge; 45 auxiliary annular check rings; 450 auxiliary receiving area; 49 a second radial washer; 5 a compensation device; 6 filling the element; 61 a first end; 610 bottom opening; 616 an inner annular groove; 62 a second end; a ring-shaped gasket member; 71 outer gasket edges; 710 a recess; 711 annular ridge; 72 inner gasket edges; 720 a boss; 721 annular groove; 500 a filter body; 501 inlet; 502 outlet; 510 a cover; 510' an ambient pressure chamber; 517 a protrusion; 518 locking grooves; 520 cup; 550 a filtration chamber; 551 body wall; 900 a filter assembly; an X-X filter axis; a Y-Y body axis; s dirty side.

Detailed Description

In the drawings, reference numeral 1 designates a filter cartridge according to a preferred embodiment of the present invention. In addition, reference numeral 900 refers to a fluid filter assembly which in turn comprises a filter cartridge 1 according to a preferred embodiment of the invention. Further, reference numeral 500 denotes a filter body adapted to accommodate the filter cartridge 1.

Now into the advantages of the present invention, the filter assembly 900 is adapted to filter fluids that may be at risk of crystallization, such as water or urea, which may be at risk of crystallization when operated at ambient conditions below 0 ℃ and-11 ℃, respectively, as already described.

According to the present invention, the filter assembly 900 is adapted to be connected to a conduit of an aqueous fluid supply system (e.g., a urea injection system).

According to the present invention, as will be described more fully below, the filter assembly 900 includes a filter cartridge 1 and a filter body 500.

Preferably, the filter assembly 900 is fluidly connectable to a tank and a suction pump (not shown) adapted to suck aqueous fluid from the tank through the filter assembly 900. In other words, the filter assembly 900 operates in a suction mode.

The filter body 500 may be connected to a circuit conduit to receive "dirty fluid" (i.e., fluid to be filtered) and to produce "clean fluid" (i.e., filtered fluid).

According to the invention, the filter body 500 defines internally a filter chamber 550, the filter cartridge 1 being accommodated in the filter chamber 550. The filter body 500 includes an inlet 501 and an outlet 502 fluidly connected to a filter chamber 550.

According to a preferred embodiment, the filter body 500 includes a cup 520 and a lid 510, the lid 510 closing the cup 520 to define a filter chamber 550 bounded by a body wall 551.

According to a preferred embodiment, cup 520 and cap 510 are threadably secured to one another. Preferably, the cap 510 is screwed into the cup 520 (inside the cup 520) as shown.

Preferably, the filter body extends in length along a body axis Y-Y. Preferably, the inlet 501 and the outlet 502 are made on a cup 520.

According to a preferred embodiment, the body wall 551 extends in length parallel to (preferably about) the body axis Y-Y.

The invention also relates to a filter insert 1. Preferably, the filter cartridge 1 is housed in the filter body 500. Preferably, the filter cartridge 1 extends in length along a filter axis X-X; with the filter cartridge 1 received in the filter body 500, the filter axis X-X corresponds to the body axis Y-Y.

According to the invention, the filter cartridge 1 comprises a tubular filter medium 2, the filter medium 2 comprising a central cavity 20. The filter medium 2 extends axially around a filter axis X-X.

According to the invention, the fluid can pass through the filter medium 2 in the radial direction.

According to a preferred embodiment, the fluid may pass through the filter medium 2 from the outside to the inside. In other words, the central cavity 20 is the "clean side" of the filter and the outer space S at the filter medium 2 is the "dirty side".

According to a preferred embodiment, the filter medium 2 is for example a nonwoven fabric made of polymer fibers (e.g. polypropylene, polyethylene or polyamide).

According to a preferred embodiment, the filter medium 2 is a pleated surface membrane (pleated surface septum) having a star geometry.

According to a preferred embodiment, the filter medium 2 is a tubular depth membrane (tubulor-shaped depth septum).

According to the invention, the filter cartridge 1 further comprises a first plate 3, the first plate 3 being at a first end of the filter medium 2, the first plate 3 comprising a first through hole 30 defined by a first edge 31 at the filter axis X-X.

In addition, according to the invention, the filter cartridge 1 further comprises a second plate 4, the second plate 4 being at the second end of the filter medium 2, the second plate 4 comprising a second through hole 40 defined by a second edge 41 at the filter axis X-X.

According to the invention, the first plate 3 and the second plate 4 are adapted to sealingly engage the body wall 551.

According to a preferred embodiment, the first plate 3 and the second plate 4 comprise a first radial gasket 39 and a second radial gasket 49, respectively. The first radial gasket 39 and the second radial gasket 49 are both radially outward to radially sealingly engage the body wall 551. Preferably, the first plate 3 and the second plate 4 have special external housing grooves for gaskets.

According to a preferred embodiment, the "dirty side" is outside the filter medium 2 and is defined at both axial ends by a first radial gasket 39 and a second radial gasket 49.

According to a preferred embodiment, as shown in the accompanying drawings, the first radial gasket 39 and the second radial gasket 49 have different radial distances from the filter axis X-X, so as to facilitate insertion into the filter body 500.

Furthermore, according to a preferred embodiment, the first plate 3 comprises an annular collar (collar) 35 extending around the X-X axis. According to a preferred embodiment, the first plate 3 comprises an annular collar 35, the annular collar 35 extending in an axial direction about the X-X axis on the opposite side of the first plate 3 with respect to the filter medium 2, so as to define a receiving area 350, the purpose of which will be described in detail below.

According to a preferred embodiment, the second plate 4 also comprises an auxiliary annular collar 45, which auxiliary annular collar 45 extends axially on the opposite side of the second plate 4 with respect to the filter medium 2, so as to define an auxiliary receiving area 450, the purpose of which will be described in detail below.

According to the invention, the filter cartridge 1 further comprises compensating means 5 of variable form and/or position in order to vary the volume of the flow portion through which the aqueous fluid flows. In particular, the change in shape and/or position of the compensating device 5 is caused by crystallization of the fluid. The change in shape and/or position of the compensating device 5 is also caused by crystallization of the filter medium 2, where applicable.

In other words, the compensation means 5 are adapted to occupy the area of fluid flow and to change their shape and position based on the state of the fluid (i.e. whether there are crystalline crystals in the fluid).

According to the invention, the compensating device 5 comprises a filling element 6 and an annular gasket element 7.

The filler element 6 is at least partially accommodated in the central cavity 20.

Preferably, the filling element 6 occupies part of the space of the central cavity, leaving room for the fluid to flow inside the central cavity 20 towards the first through hole 30 and/or the second through hole 40. In other words, the presence of the filler element 6 does not completely block the fluid path. In other words, the filling element 6 occupies a part of the volumetric area of the "clean side", so as to avoid that the "clean side" is completely filled with fluid that is likely to crystallize.

According to the invention, the change in shape and/or position of the compensating device 5 due to the formation of crystals changes the through-going part of the "clean side" of the filter medium in case the filter medium 2 is passed through from outside to inside.

The filler element 6 extending in the length direction along the filter axis X-X comprises a first end 61 and a second end 62.

Preferably, the first end 61 extends from the central cavity 20. Preferably, the first end 61 is received in the receiving region 350.

Preferably, the second end 62 protrudes from the second through hole 40. Preferably, the second end 62 protrudes from the second through hole 40 in any axial configuration of the annular gasket element 7. In other words, the second end 62 is received in the auxiliary receiving area 450.

According to a preferred embodiment, the filling element 6 has a tubular shape and is made of a rigid material (preferably a plastic material) which does not change under the influence of the fluid. According to a preferred embodiment, the filling element 6 is hollow, comprising a bottom opening 610 at the first end 61.

Instead, the annular washer element 7 elastically yields to allow axial movement of the filler element 6 when crystals are formed.

According to a preferred embodiment, the annular gasket member 7 is accommodated in a receiving area 350 present in the first plate 3.

In fact, the annular gasket element 7 is operatively connected with the first plate 3 and the filler element 6 in this way: the annular gasket member 7 includes an outer gasket edge 71 and an inner gasket edge 72, the outer gasket edge 71 sealingly engaging the first plate 3 and the inner gasket edge 72 sealingly engaging the first end 61.

According to a preferred embodiment, the outer gasket edge 71 is operatively connected to the first plate 3 by co-molding.

According to a preferred embodiment, the inner gasket edge 72 is operatively connected to the first end 61 by co-molding.

According to a preferred embodiment, the first plate 3 comprises an outer annular groove 36, in which outer annular groove 36 an outer gasket edge 71 is sealingly received.

Additionally, the first end 61 preferably includes an inner annular groove 616 with the inner gasket edge 72 sealingly received in the inner annular groove 616.

Preferably, the outer gasket edge 71 sealingly engages the first edge 31. In other words, an outer annular groove is made in the first edge 31.

Preferably, the outer gasket rim 71 sealingly engages the annular retainer 35. In other words, the outer annular groove 36 is made in the annular collar 35. For example, this embodiment is shown as an example in the drawings.

Preferably, the outer gasket edge 71 sealingly engages an abutment ring comprised in the first plate 3, which abutment ring is radially located between the first edge 31 and the annular collar 35. Preferably, an outer annular groove 36 is formed in the adjacent ring.

Preferably, the annular collar 35 comprises an outer annular groove 36 and a seat for a first radial washer 39.

According to a preferred embodiment, the outer annular groove 36 and the inner annular groove 616 are radially aligned with each other (in a "normal" gasket configuration, i.e., unchanged by the radial thrust of the fluid).

According to a preferred embodiment, the annular gasket element 7 extends radially in a molded shape.

According to a preferred embodiment, the annular gasket element 7 is shaped so as to perform an axial thrust action on the filler element 6. In particular, as an example of a preferred embodiment in the figures, the annular gasket element 7 is shown in its "normal" configuration, i.e. without elastic changes due to the presence of crystals in the fluid. The shape of the annular gasket member 7 is elastically deformed when subjected to a pushing force.

In particular, the annular gasket element 7 is shaped to comprise a recess 710, the recess 70 defining a compartment facing the filter medium 2.

Furthermore, according to a preferred embodiment, the annular gasket element 7 extends radially, comprising a projection 720 radially juxtaposed with the recess 710. Preferably, recess 710 is adjacent outer gasket edge 71 and boss 720 is adjacent inner gasket edge 72. Preferably, in some embodiments, and vice versa, the recess 710 is proximate the inner gasket edge 72 and the boss 720 is proximate the outer gasket edge 71.

According to a preferred embodiment, the annular gasket member 7 comprises at least one annular ridge 711 and at least one annular groove 721, having an "S" shaped cross section.

According to a preferred embodiment, the annular gasket member 7 is made of an elastomeric material such that it has an elastically resilient elastic yielding property. In other words, the annular gasket element 7 is in a "normal" configuration without thrust action due to the presence of crystals.

Preferably, the annular gasket member 7 is made of a closed cell elastomeric material, or is made of silicone rubber, fluorosilicone rubber, acryl rubber, or propylene and vinyl rubber.

According to a preferred embodiment, the filter cartridge 1 further comprises at least two axial locking teeth 38, the axial locking teeth 38 being adapted to snap engage a portion of the filter body 500. In particular, the axial locking teeth 38 are adapted to snap-engage the filter cartridge 1 to the cap 510.

According to a preferred embodiment, the filter cartridge 1 is adapted to be coupled to the cap 510 such that the filter cartridge 1 can be inserted into the filter chamber 550 in the operation of closing the cup 520 with the cap 510.

According to a preferred embodiment, the axial locking teeth 38 extend axially from the annular collar 35 in a direction parallel to the filter axis X-X.

Preferably, the cap 510 is provided with at least one locking groove 518 (preferably facing outwardly), the axial locking teeth 38 being received in the locking groove 518.

Additionally, according to a preferred embodiment, the cap 510 includes a protrusion 517 that extends in height to facilitate engagement of the annular gasket member 7.

Preferably, the protrusions 517 are radially disposed near the outer gasket edge 71 to enhance the sealing action against the first plate 3. In other words, the protrusions 517 are adapted to secure the annular gasket member 7 and to ensure a reliable seal of the outer gasket edge 71. In other words, the protrusion 517 is adapted to retain the outer gasket edge 71 within the outer annular groove 36 under all operating conditions of the filter cartridge 1 and filter assembly 900.

According to a preferred embodiment, the protrusion 517 is a single annular protrusion 517. According to a preferred embodiment, the outer gasket edge 71 is tightly fastened to the first plate 3 and the protrusion 517.

According to a preferred embodiment, the cap 510 axially sealingly engages the annular gasket member 7.

According to a preferred embodiment, the cover 510 is joined to the cup 520 so as to define a chamber 510' at ambient pressure: in particular, the chamber 510' at ambient pressure is defined in its lower part by the cover 510 and in its upper part by the airtight connection between the annular gasket element 7 and the first plate 3 and between the first plate 3 and the body wall 551. In this chamber 510' at ambient pressure, the aqueous fluid is not circulated and the corresponding part of the compensating device 5 is free to move (on the "clean side" or the "dirty side", or in any case in the filter chamber 550) after the formation of crystals in the space in which the aqueous fluid circulates.

In other words, the chamber 510 'at ambient pressure provides a compensation space through which the compensation means 5 passes after a change in position and/or shape caused by crystallization of the fluid, the change in position and/or shape of the compensation means 5 being formed on the opposite side of the chamber 510' at ambient pressure, in particular in the filter chamber 550. During this movement, the compensating device 5 remains in sealing connection with the filter insert 1, in particular with the first plate 3. In this way, a minimum compensation volume for the entire service life of the filter insert 1 is ensured.

According to a preferred embodiment, the cap 510 does not require any additional gasket; in other words, the annular washer element 7 and the washer present on the first plate 3 are sufficient.

Preferably, the cover 510 defines with the compensating device 5 a chamber 510' at ambient pressure.

According to a preferred embodiment, the cover 510 is partially received in the receiving area 350.

Innovatively, the filter cartridge, filter body and filter assembly described above fully achieve the objects of the invention, overcoming the common drawbacks of the prior art.

In fact, it is an object of the present invention to advantageously provide a filter cartridge, a filter body adapted to house the same, and a filter assembly, which present simple, effective and durable compensation means, solving the usual problems of the prior art.

Advantageously, the filter cartridge has a simple and reliable hermetic seal in various operating configurations (i.e., at any operating temperature, i.e., even in the presence of crystals).

Advantageously, the compensating element is connected/integrated to the filter cartridge by simplifying the structure of the filter body.

Advantageously, the compensating element is mounted in the central cavity of the filter medium to form a compact device and to optimize the exploitation of the available space.

Advantageously, the filter insert has a gasket element accommodated in a receiving area, which defines a large compensation area, in which fluid and/or fluid containing crystals can flow. Advantageously, the compensation zone is locked in the cover.

Advantageously, the filter cartridge has a very limited number of components.

Advantageously, the filter cartridge and filter assembly generally have a limited number of gaskets.

Advantageously, the assembly of the filter cartridge is simple and reliable.

Advantageously, the filter cartridge and the compensating device can be assembled/disassembled with the cover at the same time as the insertion and extraction.

Advantageously, the filler element is not subject to wear, consumption and/or breakage.

Advantageously, the filler element is made of a rigid material, facilitating the transfer of pressure from the inner cavity of the filter cartridge to the annular gasket.

Advantageously, the operative connection envisaged between the compensation means and the filter cartridge is of the removable type, so that the compensation means can be reused.

Advantageously, the operative connection between the compensating device and the filter cartridge is foreseeable to be of the removable type, making replacement and maintenance operations faster and easier.

Advantageously, the filter cartridge and the compensating device are made of a plastic material, so that the components are recyclable.

Advantageously, the cover and the compensating device are operatively connected to each other in such a way that the sealing effect of the gasket element is improved.

Advantageously, the cover and the compensating device are operatively connected to each other in such a way as to have an axial end stop for the movement of the filling element, even in the event of breakage of the gasket element.

Advantageously, the cover and the compensating device are operatively connected to each other in the following manner: any leakage of fluid that may be contained by the cap is avoided even in case of breakage of the gasket element.

Advantageously, all of the above advantages can be achieved by radial flow through the filter media from the inside to the outside, or by flow through the filter media from the outside to the inside.

It is obvious that a person skilled in the art can modify the filter cartridge and/or the filter body and/or the filter assembly described above to meet the requirements possible, all of which are included within the scope of protection defined by the following claims.

Claims

1. A filter cartridge (1) of a filter assembly (900) for a fluid, the fluid being at risk of crystallization, the filter assembly (900) comprising a filter body (500), the filter body (500) comprising a filter chamber (550) defined by a body wall (551), wherein the filter cartridge (1) is accommodated in the filter chamber (550) and extends along a filter axis (X-X), the filter cartridge (1) comprising:

-a tubular filter medium (2) extending axially around said filter axis (X-X), the filter medium (2) comprising a central cavity (20), wherein a fluid is able to pass through the filter medium (2) in a radial direction;

-a first plate (3) and a second plate (4) at the ends of the filter medium (2) adapted to sealingly engage the body wall (551), the first plate (3) and the second plate (4) comprising a first through hole (30) and a second through hole (40) at the filter axis (X-X) defined by a first edge (31) and a second edge (41), respectively;

-a shape and/or position variable compensation device (5) for varying the volume of a flow portion through which an aqueous fluid flows, wherein the shape and/or position change is caused by crystallization of the fluid, wherein the compensation device (5) comprises:

a) -a filling element (6) at least partially housed in said central cavity (20), extending in length along said filter axis (X-X), the filling element (6) comprising a first end (61) and a second end (62);

b) -an annular gasket element (7) elastically yieldable to allow axial movement of the filler element (6) based on the formation of crystallized crystals, wherein the annular gasket element (7) comprises an outer gasket edge (71) sealingly engaging the first plate (3) and an inner gasket edge (72) sealingly engaging the first end (61).

2. The filter cartridge (1) according to claim 1, wherein the first plate (3) comprises an annular collar (35), the annular collar (35) extending in an axial direction about the filter axis (X-X) on an opposite side with respect to the filter medium (2), wherein the annular collar (35) defines a receiving area (350), the first end of the filler element (6) being accommodated in the receiving area (350).

3. The filter cartridge (1) of claim 1, wherein the first plate (3) comprises an outer annular groove (36), the outer gasket edge (71) being sealingly received in the outer annular groove (36), the first end (61) comprising an inner annular groove (616), the inner gasket edge (72) being sealingly received in the inner annular groove (616).

4. The filter cartridge (1) of claim 2, wherein the outer gasket edge (71) sealingly engages the first edge (31) or sealingly engages the annular collar (35) or sealingly engages an abutment ring; the abutment ring is comprised in said first plate (3) radially between said first edge (31) and said annular collar (35).

5. The filter cartridge (1) according to claim 1, wherein the annular gasket element (7) extends radially in a molded shape, the annular gasket element (7) comprising a recess (710), the recess (710) defining a compartment facing the filter medium (2).

6. The filter cartridge (1) of claim 5, wherein the annular gasket element (7) extends radially, comprising a projection (720) radially juxtaposed with the recess (710); the recess (710) is adjacent the outer gasket edge (71) and the projection (720) is adjacent the inner gasket edge (72), or vice versa.

7. The filter cartridge (1) of claim 6, wherein the annular gasket member (7) comprises at least one annular ridge (711) and at least one annular groove (721) so as to have an "S" shaped cross section.

8. The filter cartridge (1) according to claim 1, characterized in that the annular gasket element (7) is made of a closed-cell elastomer material, silicone rubber, fluorosilicone rubber, acryl rubber, or propylene and vinyl rubber, so that it has an elastically resilient yield property.

9. The filter cartridge (1) according to claim 1, wherein the filler element (6) extends axially such that the second end (62) protrudes from the second through hole (40) in any axial configuration of the annular gasket element (7).

10. The filter cartridge (1) of claim 1, wherein the filler element (6) is hollow comprising a bottom opening (610) at the first end (61).

11. The filter cartridge (1) of claim 1, wherein the first plate (3) and the second plate (4) comprise a first radial gasket (39) and a second radial gasket (49), respectively, the first radial gasket (39) and the second radial gasket (49) each facing radially outwards to seal the body wall (551) radially.

12. The filter cartridge (1) according to any one of the preceding claims, wherein the first plate (3) comprises at least two axial locking teeth (38), the axial locking teeth (38) being adapted to be snap-engaged to a portion of the filter body (500).

13. The filter cartridge (1) according to claim 1, wherein the fluid is water or urea.

14. The filter cartridge (1) according to claim 1, wherein the fluid passes through the filter medium (2) from the outside to the inside.

15. The filter cartridge (1) according to claim 2, wherein the annular gasket element (7) is accommodated in the receiving area (350).

16. The filter cartridge (1) of claim 12, wherein the axial locking teeth (38) are adapted to snap-engage to a cap (510) of the filter body (500).

17. A filter body (500) of a filter assembly (900) for fluids, which is at risk of crystallization, comprising a filter cartridge (1) according to any one of the preceding claims, wherein the filter body (500) comprises a cup (520) and a cover (510) closing the cup (520), the cup (520) and the cover (510) being mutually screwable to define a filter chamber (550) delimited by a body wall (551), wherein the filter chamber (550) is capable of accommodating the filter cartridge (1),

the cover (510) comprises a protrusion (517), which protrusion (517) extends in height to engage the outer gasket edge (71) close to the annular gasket element (7) to improve the sealing action against the first plate (3).

18. The filter body (500) according to claim 17, wherein the cover (510) engages with the first plate (3) of the filter cartridge (1) to define a chamber (510') at ambient pressure in which the corresponding portion of the compensating device (5) is free to move.

19. The filter body (500) according to claim 17, for use in combination with a filter cartridge (1) according to claim 12, wherein the cover (510) comprises at least one locking groove (518), in which locking groove (518) the axial locking tooth (38) is received in the filter cartridge (1) being connected to the cover (510).

20. The filter body (500) of claim 17, wherein the protrusion (517) is a single annular protrusion (517).

21. A filter assembly (900) for a fluid at risk of crystallization, comprising a filter cartridge (1) according to any one of claims 1 to 16 and a filter body (500) according to any one of claims 17 to 20.