EP3982062A1

EP3982062A1 - A filter assembly for a heat exchanger

Info

Publication number: EP3982062A1
Application number: EP20461567.8A
Authority: EP
Inventors: Andrzej JUGOWICZ; Piotr LUPINIAK; Grzegorz Romanski
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2020-10-09
Filing date: 2020-10-09
Publication date: 2022-04-13

Abstract

A filter assembly (1) for a heat exchanger, comprising a first tubular section (11a, 20a) and a second tubular section (15a, 30a) coaxial with respect to each other, and further comprising a filter element (10) comprising: at least one filter mesh (12) disposed at interface between the first tubular section (20a) and the second tubular section (30a), a sealing element (14) disposed along periphery of the at least one filter mesh (12); wherein the filter element (10) further comprises a protection ring (16) disposed around and secured to at least a portion of the sealing element (14), the protection ring (16) adapted to be removably secured to engaging portion of at least one of the first tubular section (11a, 20a) and the second tubular section (30a), when the first tubular section (11a, 20a) and the second tubular section (15a, 30a) are connected to each other.

Description

The present invention relates to filter assembly for heat exchanger.
Conventional air conditioning system, for example for a vehicle cabin, includes a condenser, an evaporator, an expansion device, a compressor and a heater. The compressor pumps refrigerant gas up to a high pressure and temperature. Thereafter, refrigerant gas enters the condenser, where refrigerant gas rejects heat energy to external ambient (through ambient air or a specific low temperature coolant circuit), gets cooled, and condenses into liquid phase. Subsequently, the expansion valve regulates refrigerant liquid to flow at proper rate, reducing its pressure due its expansion, and finally, the cooled liquid refrigerant flows to the evaporator, where the cooled liquid refrigerant is evaporated, reducing its temperature. As the liquid refrigerant evaporates, the refrigerant extracts or absorbs heat energy from air inside an enclosure to be conditioned, specifically, a vehicle cabin in case of a vehicle air conditioning system and returns to the compressor, and the above cycle repeats. In the process, the heat is extracted from inside the vehicle cabin and rejected to outside vehicle cabin, resulting in cooling of air inside the vehicle cabin.
The conventional air conditioning system configured with expansion valves are also configured with a receiver drier that is disposed in the high-pressure section of the air conditioning system, usually located between condenser and expansion valve in the air conditioning loop. The receiver drier is in form of an air-tight container of a tubular configuration with an inlet for receiving liquid refrigerant from a condenser and an outlet for delivering the liquid refrigerant from which moisture and debris is removed. The receiver drier acts as a temporary storage for refrigerant (and optionally oil). The receiver drier receives a desiccant material to absorb moisture (water) that may have entered inside the air conditioning system.
The air conditioning system may also include a filter to trap debris that may cause damage to critical components disposed in the air conditioning loop. The filter may be disposed between a first tubular-section of a connector block of the condenser and a second tubular section connecting the receiver drier to the connector block. The filter prevents any impurities or debris carried with the fluid, particularly, refrigerant flowing from tank to the second tubular section through the first tubular section from reaching the second tubular section and subsequently reaching the receiver drier. The filter prevents the impurities or the debris from reaching critical elements of the air-conditioning system, particularly, compressor or expansion device that performs inefficiently or fails in case the impurities or debris enter into the compressor or the expansion device. In order to avoid refrigerant leakage and to prevent moisture or debris from entering into the air conditioning loop a sealing element is required to seal the receiver drier and prevent refrigerant from escaping out of the receiver drier. If in case any moisture reaches the receiver drier, the same is absorbed by, the desiccant material received inside the receiver drier.
Generally, the filter element disposed at interface between the first tubular section and the second tubular section includes at least one filter mesh and a sealing element disposed along a periphery of the at least one filter mesh. The filter mesh prevents debris carried with the refrigerant flowing from the first tubular section to the second tubular section from reaching the second tubular section. The sealing element of elastomeric material forms an airtight connection at the interface between the first tubular section and the second tubular section to prevent moisture or other impurities from entering inside the receiver drier through the interface between the first tubular section and the second tubular section.
The first tubular section and the second tubular section are coaxial with the same radial dimension. With such configuration, the sealing element is pinched between engaging portions of the first tubular section and the second tubular section as illustrated in FIG. 1 . As the sealing element is of soft elastomeric material, the sealing element can get damaged due to being pinched. The damaged sealing element fails to prevent leakage of the refrigerant and entry of the moisture or debris into the second tubular section through the interface between the first tubular section and the second tubular section.
To prevent the pinching of the sealing element between the first tubular section and the second tubular section and to prevent damage caused due to pinching, the radial dimensions of the tubular sections at opposite sides of the filter mesh are formed differently. The second tubular section at interface between the first tubular section and the second tubular section at opposite sides of the filter mesh is enlarged to form a filter cavity. The filter cavity is covered by a cover plate. The cover plate in turn receives end of the first tubular section. The filter mesh is disposed in the filter cavity at the interface between the first tubular section and the second tubular sections and is held between the cover plate and the filter cavity as illustrated in FIG. 2 . However, such configuration requires additional element in the form of cover plate and increases pressure drop across the filter element, thereby detrimentally affecting the filtering capacity of the filtering element.
Accordingly, there is a need for a filter element that can be located between co-axial first and second tubular sections, while still addressing issue of pinching of the sealing element and drawbacks associated with pinching of the sealing element. Further, there is a need for a filter element that prevents deformation of the filter mesh and the sealing element. Furthermore, there is a need for a filter element that is robust, exhibits enhanced service life and low maintenance. Further, there is a need for a filter element that can be securely located in desired position, provides sealing, prevents leakages and effectively and efficiently filters fluid passing there through, without increasing pressure drop across the filter element and without causing pinching of the sealing element.
An object of the present invention is to provide a filter element that obviates the drawbacks of convention filter element prone to inefficient filtering due to pressure drop across the filter element, inefficient sealing and limited service life due a damage caused to the sealing element due to pinching.
Another object of the filter element of the present invention is to provide efficient filtering, sealing and extended service life that in spite of the tubular sections at opposite sides of the filter element being co-axial and the same radial dimension.
Still another object of the present invention is to provide a filter element that is simple in construction.
Yet another of the present invention is to provide a filter element that involves fewer parts and accordingly is inexpensive, reliable, and convenient to assembly and manufacture.
Another object of the present invention is to provide a filter element that involves comparatively lower inventory and manufacturing costs associated with manufacturing thereof as compared to inventory and manufacturing costs associated with manufacturing of conventional filter element.
Still another object of the present invention is to provide a filter element that effectively performs its function of preventing moisture and debris from reaching the critical elements of the air conditioning system, thereby improving efficiency and performance of the air conditioning system.
In the present description, some elements or parameters may be indexed, such as a first element and a second element. In this case, unless stated otherwise, this indexation is only meant to differentiate and name elements which are similar but not identical. No idea of priority should be inferred from such indexation, as these terms may be switched without betraying the invention. Additionally, this indexation does not imply any order in mounting or use of the elements of the invention.
An object of the invention is a filter assembly for a heat exchanger, comprising a first tubular section and a second tubular section coaxial with respect to each other, and further comprising a filter element comprising: at least one filter mesh disposed at interface between the first tubular section and the second tubular section, a sealing element disposed along periphery of the at least one filter mesh; wherein the filter element further comprises a protection ring disposed around and secured to at least a portion of the sealing element, the protection ring adapted to be removably secured to engaging portion of at least one of the first tubular section and the second tubular section, when the first tubular section and the second tubular section are connected to each other.
Preferably, the protection ring is adapted to be received in a recess configured on engaging portion of at least one of the first tubular section and the second tubular section.
Preferably, the protection ring is complimentary to and received in the recess formed on the engaging portion of the first tubular section.
Preferably, the protection ring is complimentary to and received in the recess formed on the engaging portion of the second tubular section.
Preferably, the protection ring is complimentary to and partially received in the recess formed on the engaging portion of the first tubular section and is complimentary to and partially received in the recess formed on the engaging portion of the second tubular section, when the first tubular section is assembled to the second tubular section.
Preferably, the at least one filter mesh is of plastic material, particularly polyamide material.
Preferably, the at least one filter mesh comprises a first filter mesh and a second filter mesh, the first filter mesh and the second filter mesh are of the same sieve size.
Preferably, the first filter mesh and the second filter mesh are of different sieve size.
Preferably, the sealing element is of rubber material.
Preferably, the sealing element is over-moulded over the at least one filter mesh.
Preferably, the protection ring is a metallic ring.
Preferably, the protection ring is of stainless steel.
Preferably, the first tubular section and the second tubular section that are removably connected to each other by a nut and bolt assembly.
Another object of the invention is a plate condenser with an outlet for a refrigerant, wherein it comprises a filter assembly according to any preceding claim, a second tubular section being attached to said outlet.
Other characteristics, details and advantages of the invention can be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein:

FIG. 1 illustrates a schematic representation of a conventional filter element disposed at interface between a first tubular section and a second tubular section that are co-axial and of the same radial dimension;
FIG. 2 illustrates a schematic representation of a filter element in accordance with one embodiment of the present invention disposed at an interface between a first tubular section and a second tubular section of differentiated radial dimension;
FIG. 3 illustrates a schematic representation of a filter element in accordance with another embodiment of the present invention disposed at an interface between a first tubular section and a second tubular section that are co-axial and of substantially the same radial dimension;
FIG. 4 illustrates an isometric view of the filter element of FIGS. 2 and 3 ; and
FIG. 5 illustrates a sectional view of the filter element of FIGS. 2 and 3 .

It must be noted that the figures disclose the invention in a detailed enough way to be implemented, said figures helping to better define the invention if needs be. The invention should however not be limited to the embodiment disclosed in the description.
A filter assembly with a filter element for a heat exchanger, particularly a condenser disposed in an air-conditioning loop of a vehicle is disclosed in accordance with an embodiment of the present invention. The filter element includes at least one filter mesh and a sealing element. The at least one filter mesh is disposed at interface between a first tubular section and second tubular section. The sealing element is disposed along periphery of the at least one filter mesh. The filter element further includes a protection ring disposed around the sealing element. The protection ring is removably received in a recess configured on engaging portion of at least one of the first tubular section and the second tubular section. The first tubular section and the second tubular section are coaxial with respect to each other and of substantially the same radial dimension. With such configuration, the filter element is accurately located in desired position at the interface between the first tubular section and the second tubular section. As the engaging portions of the first and second tubular sections are interacting with the protection ring and not with the sealing element, the problem of pinching of the sealing element is addressed. However, the filter element of such configuration is not limited to use in air-conditioning loop for use in vehicular environment. The filter element of the present invention is also applicable in other applications, where the filter element is required to perform functions of filtering, sealing and locating itself between a first tubular section and a second tubular section of the same radial dimension that are co-axial to each other. The filter element of the present invention finds application where the problem of pinching and deformation of the sealing element and deformation of the filter mesh of the filter element disposed between the first and the second tubular sections due to the first and second tubular sections being coaxial and the same radial dimension is to be addressed.
FIG. 1 illustrates a schematic representation of a conventional filter element 3 disposed at interface between a first tubular section 1a and a second tubular section 2a. The first tubular section 1a is in fluid communication for example with downstream portion of a refrigerant circuit, whereas the second tubular section 2a may be part of a connection block that is fluid communication with a tank of a condenser. The conventional filter element 3 is disposed at the interface between the first tubular section 1a and the second tubular section 2a. The connection between the first tubular section 1a and the second tubular section 2a at the interface thereof is required to be such that the first tubular section 1a and the second tubular section 2a are in fluid communication, the fluid crossing the conventional filter element 3 is filtered as the fluid passes the conventional filter element 3 and a sealing connection is formed at the interface to prevent entry of impurities. Accordingly, the conventional filter element 3 includes a sealing element 3a and a filter mesh 3b. Such configuration of the conventional filter element 3 is aimed to prevent impurities from reaching the receiver drier 1 and seal the interface between the first tubular section 1a and the second tubular section 2a. However, as the first tubular section 1a and the second tubular section 2a are co-axial i.e. are having a common central axis "c" and are of the same radial dimension, the sealing element 3a get pinched between the engaging portions of the first tubular section 1a and the second tubular section 2a. As the sealing element 3a is of soft elastomeric material, the sealing element 3a can get damaged due to being pinched. The damaged sealing element 3a fails to prevent leakage of the refrigerant and entry of the moisture or debris into the first and second tubular sections 1a and 2a at the interface between the first and second tubular sections 1a and 2a.
FIG. 2 illustrates a schematic representation of an arrangement of a first tubular section 11a and a second tubular section 15a with a filter element 10 disposed at interface between the first tubular section 11a and the second tubular section 15a. The first tubular section 11a is for example in fluid communication with downstream elements of a refrigerant circuit, whereas the second tubular section 15a is part of a connection block 15 that is fluid communication with a condenser. For example, the connection block may be attached to an outlet opening on a plate condenser. In one case, the connection block is connected directly to a terminal plate of a plate condenser. The filter element 10 includes a sealing element 14 and a filter mesh 12. The sealing element 14 is disposed around at least a portion of the filter mesh 12. The filter element 10 further includes a protection ring 16 disposed around and secured to at least a portion of the sealing element 14. In one example, the protection ring 16 is disposed along the entire periphery of the sealing element 14. The protection ring 16 is of stainless steel. The arrangement is capable of preventing pinching of the sealing element 14 as the radial dimensions of the first and second tubular sections 11a and 15a at opposite sides of the filter mesh 12 are of different dimension in spite of the first and the second tubular sections 11a and 15a being co-axial, i.e. having the same central axis "C". More specifically, the portion of the second tubular section 15a proximal to interface between the first tubular section 11a and the second tubular section 15a at opposite sides of the filter mesh 12 is comparatively larger than the first tubular section 11a to form a filter cavity 15b. The filter cavity 15b is covered by a cover plate 17. The cover plate 17 in turn receives an end portion 11b of the first tubular section 11a. The filter mesh 12 is disposed in the filter cavity 15b at the interface between the first tubular section 11a and the second tubular section 15a and is held between the cover plate 17 and the filter cavity 15b as illustrated in FIG. 2 . Such configuration of the filter element 10 prevents the pinching of the sealing element 14 between the first tubular section 11a and the second tubular section 15a and prevents damage caused due to pinching. Also the filter cavity 15b, having an area similar to the area of the filter mesh 12 and extending towards another opening of the connection block 15 enables effective filtering of the outgoing refrigerant by providing a volume for the refrigerant to be filtered.
The filter element 10 includes at least one filter mesh 12 and a sealing element 14. The at least one filter mesh 12 is disposed at interface between the first tubular section 20a and the second tubular section 30a. In one example, the filter element 10 as illustrated in FIG. 4 and FIG. 5 includes two filter meshes, a first filter mesh 12a and a second filter mesh 12b. The first filter mesh 12a and the second filter mesh 12b are of the same sieve size. In another example, the first filter mesh 12a and the second filter mesh 12b are of different sieve size. The at least one filter mesh 12 is of plastic material, particularly polyamide material. The at least one filter mesh 12 of the filter element 10 is capable of filtering out debris carried with fluid flowing across the filter element, for example, fluid flowing from the second tubular section 30a to the first tubular section 20a, thereby preventing the debris from reaching the first tubular section 20a. Interposing a plurality of filter elements with the filter meshes arranged so that the sieves are in a asymmetric configuration with respect to each other enables better filtering properties.
FIG. 3 illustrates a schematic representation of the filter element 10 disposed at the interface between a first tubular section 20a and a second tubular section 30a that are co-axial, i.e. are having the same central axis "Z" and are of the same radial dimension. Particularly, the first tubular section 20a and the second tubular section 30a are of substantially the same radial dimension at least at the interface thereof. The sealing element 14 is disposed along periphery of the at least one filter mesh 12. The sealing element 14 is of rubber material. In one example, the sealing element 14 is over-moulded over the at least one filter mesh 12. In another example, the sealing element 14 is formed of the same material as that of the at least one filter mesh 12 and is integrally formed with the at least one filter mesh 12. The sealing element 14 is capable of a forming a sealing connection at the interface between the first tubular section 20a and the second tubular section 30a to avoid refrigerant leakage and prevent moisture or debris from entering into the air conditioning loop.
The first tubular section 20a and the second tubular section 30a may be assembled to each other using nut and bolt assembly 40. More specifically, bolts 40a may pass through portions connected to the first tubular section 20a and the second tubular section 30a and nuts 40b engage with end portions of the bolts 40a to induce tension in the bolts 40a, thereby holding the first tubular section 20a against the second tubular section 30a. Such configuration provides access to the filter element 10 by disassembling the first tubular section 20a from the second tubular section 30a. Such configuration of the first tubular section 20a and the second tubular section 30a assembled together by the nut and bolt assembly 40 provides convenient and quick access to the filter element 10 for servicing and replacement thereof, i.e. such configuration provides better serviceability. Other means of releasable connection of those tubular elements are also foreseen.
The protection ring 16 is removably secured to engaging portion of at least one of the first tubular section 20a and the second tubular section 30a, when the first tubular section 20a and the second tubular section 30a are assembled to each other. Specifically, the protection ring 16 is received in a recess configured on engaging portion of at least one of the first tubular section 20a and the second tubular section 30a, when the first tubular section 20a and the second tubular section 30a are assembled to each other. In one example, the protection ring 16 is complimentary to and received in the recess formed on the engaging portion of the first tubular section 20a. In another example, the protection ring 16 is complimentary to and received in the recess formed on the engaging portion of the second tubular section 30a. In yet another example, the protection ring 16 is complimentary to and partially received in the recess formed on the engaging portion of the first tubular section 20a and is complimentary to and partially received in the recess formed on the engaging portion of the second tubular section 30a, when the first tubular section 20a is assembled to the second tubular section 30a. The protection ring 16 locates and securely holds the filter element 10 in a desired position between the first tubular section 20a and the second tubular section 30a.
With such configuration, the filter element 10 is accurately positioned at the interface between the first tubular section 20a and the second tubular section 30a. Further, with such configuration the pinching of the sealing element 14 between the first tubular section 20a and the second tubular section 30a is prevented even though the first tubular section 20a and the second tubular section 30a are coaxial with respect to each other and of substantially the same radial dimension. More specifically with such configuration, the engaging portions of the first tubular section 20a and the second tubular section 30a interact with the protection ring 16 instead of the sealing element 14 and hence the pinching of the sealing element 14 and damage to the sealing element 14 is prevented. Also with such configuration of the protection ring 16 disposed along at least a portion of the periphery of the sealing element 14, the deformation of the at least one filter mesh 12 and the sealing element 14 is also prevented. However, the present invention is not limited to any particular configuration of the protection ring 16, any particular material of the protection ring 16 and way of securing the protection ring 16 around the sealing element 14, as long as the protection ring 16 is complimentary to and received in the recess configured on engaging portion of at least one of the first tubular section 20a and the second tubular section 30a. Such configuration of the protection ring 16 helps to locate the filter element 10 and the protection ring 16 is able to withstand the axial holding or pinching forces exerted by the assembly of the first tubular section 20a and the second tubular section 30a during assembly thereof without getting damaged or deformed.

Claims

A filter assembly (1) for a heat exchanger, comprising a first tubular section (11a, 20a) and a second tubular section (15a, 30a) coaxial with respect to each other, and further comprising a filter element (10) comprising:
• at least one filter mesh (12) disposed at interface between the first tubular section (20a) and the second tubular section (30a),

• a sealing element (14) disposed along periphery of the at least one filter mesh (12); and
characterized in that the filter element (10) further comprises a protection ring (16) disposed around and secured to at least a portion of the sealing element (14), the protection ring (16) adapted to be removably secured to engaging portion of at least one of the first tubular section (11a, 20a) and the second tubular section (30a), when the first tubular section (11a, 20a) and the second tubular section (15a, 30a) are connected to each other.
A filter assembly (1) according to claim 1, wherein the protection ring (16) is adapted to be received in a recess configured on engaging portion of at least one of the first tubular section (11a, 20a) and the second tubular section (15a, 30a .
A filter assembly (1) as claimed in claim 2, wherein the protection ring (16) is complimentary to and received in the recess formed on the engaging portion of the first tubular section (11a, 20a).
A filter assembly (1) as claimed in the claim 2, wherein the protection ring (16) is complimentary to and received in the recess formed on the engaging portion of the second tubular section (15a, 30a).
A filter assembly (1) as claimed in any of the preceding claims, wherein the protection ring (16) is complimentary to and partially received in the recess formed on the engaging portion of the first tubular section (11a, 20a) and is complimentary to and partially received in the recess formed on the engaging portion of the second tubular section (15a, 30a), when the first tubular section (11a, 20a) is assembled to the second tubular section (15a, 30a).
A filter assembly (1) as claimed in the previous claim, wherein the at least one filter mesh (12) is of plastic material, particularly polyamide material.
A filter assembly (1) as claimed in any of the preceding claims, wherein the at least one filter mesh (12) comprises a first filter mesh (12a) and a second filter mesh (12b), the first filter mesh (12a) and the second filter mesh (12b) are of the same sieve size.
A filter assembly (1) as claimed in the previous claim, wherein the first filter mesh (12a) and the second filter mesh (12b) are of different sieve size.
A filter assembly (1) as claimed in any of the preceding claims, wherein the sealing element (14) is of rubber material.
A filter assembly (1) as claimed in any of the preceding claims, wherein the sealing element (14) is over-moulded over the at least one filter mesh (12).
A filter assembly (1) as claimed in any of the preceding claims, wherein the protection ring (16) is a metallic ring.
A filter assembly (1) as claimed in any of the preceding claims, wherein the protection ring (16) is of stainless steel.
A filter assembly (1) as claimed in any one of the preceding claims wherein the first tubular section (11a, 20a) and the second tubular section (15a, 30a) that are removably connected to each other by a nut and bolt assembly (40).
A plate condenser with an outlet for a refrigerant, wherein it comprises a filter assembly (1) according to any preceding claim, a second tubular section (15a, 30a) being attached to said outlet.