FILTER DEVICE FOR FLUIDS

Abstract

The invention relates to a filter device for fluids, comprising a housing (1) accommodating at least one filter element (5), which has an inlet (47) for the supply of fluid to be purified to a non-filtrate chamber (49) of the housing (1), which is separated from a filtrate chamber (46) of the housing (1) by the filter medium (33) of the respective filter element (5), having an outlet (42) for filtrate, and comprising a magnetic field-generating unit (57) arranged inside the non-filtrate chamber (49), which has an adhering surface (51) in the form of a sleeve for ferromagnetic particles attached thereto by means of a magnetic force effect. The invention is characterized in that in the non-filtrate chamber (49), the respective sleeve (51) extends outside of the respective filter element (5) parallel to the inlet (47) and transversely to the outlet (42), and that the non-filtrate chamber (49) at least partially encompasses the outlet (42) at the point of transition to the filtrate chamber (46).

Description

The invention concerns a filter device for fluids according to the characteristics of the preamble of claim 1.

Pre-scalping of ferromagnetic contaminants form the fluid to be filtered using magnetic force is prior art for filter devices. Plant and machinery that employs a fluid circuit for lubrication and/or cooling of mechanical equipment, such as transmissions or pumps, there are always metal particles present in the fluid through friction during operation, in particular in the instance of transmissions that are under high load in heavy machinery such as wind turbines or cement mills. Ferromagnetic contamination of the fluid also occurs in other kinds of process fluids to a varying degree. In particular in detergent solutions often used in plants for the automatic manufacture of parts, a high concentration of ferromagnetic particles can be found in the fluid. The separation of particles significantly increases the service life of the filter elements, particularly in fluids with high contaminant concentrations.

The documents DE 10 2006 062 807 B4 and DE 10 2013 014 453 A1 disclose examples of known devices. As a device that generates a magnetic field, said known filter devices use a magnetic rod with permanent magnets, also called a magnetic core, which extends in those devices into the inner space of the respective filter element and is attached to a housing lid of the filter device. The outside of the magnetic rod forms the adhering surface on which the metallic particles are deposited in operation. In order to dispose of the deposits in the known device, the housing lid has to be unscrewed to be able to remove the magnetic rod together with the filter element from the housing. The magnetic rod must then be removed from the filter element to be able to remove the particles that adhere to the outside of the magnetic rod. The removal of said particles is rather difficult since they are retained by the magnetic force on the outside of the magnetic rod. The use of the known filter devices thus requires a correspondingly large effort in terms of maintenance and time.

The document U.S. Pat. No. 8,636,907 B1 discloses a filter device of this kind for fluids, comprising a housing for at least one filter element, wherein said housing has an inlet for supplying the fluid to be cleaned into an unfiltrate chamber of the housing, which is separated by the filter medium of the respective filter element from a filtrate space of the housing, which is provided with an outlet for filtrate, comprising a magnetic field-generating device disposed inside the unfiltrate chamber, which provides an adhering surface for ferromagnetic particles that adhere thereto due to the magnetic force and which is formed by at least one casing that envelopes the associated magnetic field-generating device, where said casing extends from at least one opening in the housing wall into the unfiltrate chamber and in which the respective magnetic field-generating device may be movably accommodated in such a way that it can be inserted into the casing and at least partially removed from the same.

In the known solution the respective casing of the magnetic field-generating device protrudes into the respective filter element itself or between said elements, which on the one hand impairs the filtration of the unfiltrate supplied via the inlet, and on the other hand makes it more difficult to remove the respective filter element and replace it with a new one.

Based upon said prior art it is the object of the invention to provide a filter device of the kind described, which is characterised by an improved operating performance, in particular concerning filtration, and provides an easier way to operate the device.

According to the invention, this object is met by a filter device that exhibits the characteristics of claim 1 in its entirety.

Due to the fact that, according to the characterising part of claim 1, the respective casing of the associated magnetic field-generating device extends outside the respective filter element in the unfiltrate chamber, parallel to the unfiltrate inlet and transverse to the filtrate outlet, and that the unfiltrate chamber surrounds at least partially the outlet at the transition point to the filtrate space, the respective magnetic field-generating device is separated from the respective filter element in the device housing, so that neither the filtration process nor the change of a used filter element to a new filter element are impaired.

The magnetisable particles introduced via the unfiltrate inlet are already captured at the inlet point into the housing by the respective magnetic field-generating device before they reach the respective filter element, in that said particles adhere to a casing that essentially surrounds the magnetic field-generating device. When removing the moveable, magnetic field-generating device, which in turn removes the magnetic force, the now no longer attracted particles drop away from the casing and can be easily removed from the unfiltrate chamber, for example through flushing out. The maintenance effort for removing and handling of the separated particles is thus significantly reduced with the filter device according to the invention, wherein the spatial separation of the particle removal function through the magnetic field-generating device and the other particle removal through the respective filter element inside the common device housing is also a contributing factor.

In a particularly preferred embodiment of the filter device according to the invention provision is made that the housing, at least in operation, extends along a vertical axis, which is comprised of at least two housing sections of which the lower housing section is provided with the inlet and the outlet as well as the respective magnetic field-generating device, and that the other housing sections serve to hold at least one filter element. This makes it possible for the lower housing section to preferably remain stationary with a stand on a floor, and by removing the respective further housing section the filter elements can be made accessible for the replacement process. The remaining filter device remains as base on the floor as module on a stand, which makes assembly with the further modules easier.

In a further preferred embodiment of the filter device according to the invention provision is made that the bottom of the lower housing section is closed and is provided with at least one openable outlet for particles in such a way that, with a preferably closed filtrate outlet, the unfiltrate flowing in via the inlet flushes off the particles collected by the respective magnetic field-generating device from said device and/or cleans the lower housing section from contaminating particles. In this manner it is possible to promptly discharge the magnetisable particles, captured through the respective magnetic field-generating device, via the openable and closable outlet at the bottom end of the lower housing section over the shortest possible path from the housing of the filter device.

In a particularly space-saving manner provision may be made that at both sides of the filtrate outlet and arranged at the same level are two parallel to each other oriented magnetic field-generating devices with their casings, which extend at least partially, preferably fully, through the lower housing section with its collecting chamber for magnetisable particles. This makes it possible to establish homogenous magnetic fields in the vicinity of the inlet.

In particularly advantageous exemplary embodiments the respective magnetic field-generating device is comprised of a magnetic rod formed through a group of permanent magnets, wherein said magnetic rod is moveable inside a tubular casing and is accessible at one end of the tubular casing for handling purposes. Whilst the magnetic field generated by permanent magnets constitutes a preferred exemplary embodiment, it is apparent that the respective casing may contain a removable device for generating an electromagnetic field.

The arrangement may advantageously be such that more than one tubular casing for a respective magnetic field-generating device, such as a magnetic rod, is provided. Said casings may in this instance extend at a lateral or vertical distance from each other into the unfiltrate chamber or through the same.

In particularly advantageous exemplary embodiments provision is made that the lower housing section is provided with a bottom part that forms the bottom-end closing means, the base of which forms the lower closing means of the unfiltrate chamber, which extends along the outside of the filter medium of the respective filter element upwards, which is disposed in an axial distance from the base of the bottom part, and that at least one tubular casing extends in horizontal direction through the part of the unfiltrate chamber between the base of the bottom part and the filter element. Thus the respective casing, which forms the adhering surface, is disposed directly in the inflow section of unfiltrate into the housing, which causes a pre-scalping of particles before the unfiltrate rises with its non-magnetisable particle contamination to the filter element with its filter medium located above.

The arrangement may advantageously be such that on an element seat, which establishes the axial distance of the respective filter element from the base of the bottom part, a fluid connection is provided between the inner, hollow space of the filter element, which during the filtration process forms the filtrate chamber, and an outlet line for filtrate as part of the outlet, wherein a tubular casing each extends through the unfiltrate chamber on both sides of the outlet line at a distance from the base of the bottom part.

The outlet line may preferably extend coaxial to the vertical axis from the element seat to the filtrate outlet or filtrate discharge located at the base of the bottom part, wherein besides the filtrate outlet an outlet is provided on the base of the bottom part for the ferromagnetic particles that have dropped from the respective casing. Said additional outlet may be provided with a shut-off means that opens up the outlet for the purpose of flushing out the particles when required.

Alternatively, the arrangement may be such that the outlet line extends from the element seat to the filtrate outlet located on the side wall of the housing, wherein at the base of the bottom part, coaxial to the vertical axis, the outlet for the ferromagnetic particles, which have dropped from the respective casing, is provided.

In particularly advantageous exemplary embodiments casings are provided in form of tubes that extend from one housing side wall to another housing side wall, wherein said tubes are preferably closed at one end and provide at the other end access for a moveable magnetic rod.

In their inserted state the magnetic rods may extend up to a closed end of the tube, and may be provided with an end section in form of a handhold at another end of the tube. The protruding section may be provided with a handhold for manual operation.

The invention will now be described in detail by way of exemplary embodiments depicted in the drawing.

Shown are in:

FIG. 1 a perspective view of an exemplary embodiment of the filter device according to the invention in vertical cross-section;

FIG. 2 a schematically simplified longitudinal section of the exemplary embodiment in FIG. 1;

FIG. 3 a perspective view of a second exemplary embodiment of the filter device according to the invention in vertical cross-section;

FIG. 4 a perspective view of the housing section of the second exemplary embodiment of the filter device according to the invention, which accommodates the bottom part only, shown at a larger scale compared to FIG. 3; and

FIG. 5 a perspective view in horizontal cross-section of the lower part of the housing of the second exemplary embodiment, looking at the base of the bottom part.

The invention is described by way of exemplary embodiments with reference to the attached drawings, in which, in a circular-cylindrical filter housing 1, which extends along a vertical axis 3 (FIG. 2), a filter cartridge may be housed, which in the examples shown is formed by two filter elements 5 of equal design. The housing 1 is formed by three housing sections that are screwed together, of which the top section 7 is closed off through an upper end section 9, which is provided with a centrally located, closable vent opening 11. Following the upper housing section 7 is a central, tubular housing section 13, followed by a lower housing section 15. This merges into a bottom part 17 that forms the lower housing end, the base 19 of which has a slightly outwards-domed bottom area.

To support the filter cartridge, which is made up of the filter elements 5, an element seat 21 is provided in form of an annular member. Said annular member is provided with a socket-like, axially upwards protruding projection 25 that serves as connector for the lower filter element 5 and as seat for its end cap 23 that faces it, wherein said projection 25 surrounds a central opening 27 of the element seat 21. The projection 25 that forms the connector is provided on the radially outer side with a bevelled surface that rests against a complementary bevelled surface that protrudes from the end cap 23 of the filter element 5. The remaining end caps 23 of the filter elements 5 are also provided with said complementary protruding bevelled surfaces, through which the lower filter element 5 and the upper filter element 5 are also attached to each other, wherein a sealing ring is disposed between each of the matching bevelled surfaces, which are not visible in the drawing. A cover means 29 is provided as upper end cover for the filter cartridge, which cups the projection 25 of end cap 23 of the upper filter element 5, wherein said cover means 29 is provided with a centrally located venting means 31.

As is common practice with such filter arrangements, a fluid-permeable supporting tube 35 is in contact with the inside of the filter medium 33 of the filter elements 5, which extends all the way from the end cap 23 located on the element seat 21 to the upper end cap 23 of the upper filter element 5, and which is strengthened in the upper section through a reinforcement ring 37. The annular member of the element seat 21 is retained on a supporting plate 39, which in turn is attached to the housing by a coaxially extending tube 41. Beginning from the central opening 43 of the supporting plate 39, said tube 41 forms the outlet through which the filtrate flows out from the inner filter cavity 46 of the filter cartridge during the filtration process and is discharged via a filter outlet 42. The tube 41 as part of the filter outlet 42 is supported via radially extending webs 45 on the inner housing wall of the lower housing section 15, which extend in radial direction at the transition from the lower housing section 15 to the bottom part 17.

The tube 41 exits the housing 1 at the base 19 of the bottom part 17 coaxial to axis 3. An inlet 47 is provided in the section between the webs 45 and the supporting plate 39 of the element seat 21 in the side wall of the housing for the supply of unfiltrate to the part of the unfiltrate chamber 49 that follows inlet 47, which is inside the lower part of the housing section 15 and within the following bottom part 17. The unfiltrate chamber 49 extends upwards via the outside of the supporting plate 39 of the element seat 21 and along the outside of the filter medium 33 of the filter elements 5 to the upper housing end.

At the level of the lower edge of the inlet 47 and above the webs 45 the tubes 51 extend from one housing side wall to another housing side wall. The tubes 51 extend fully closed from the access openings 53 in the housing wall and through the entire unfiltrate chamber 49. Thus the internal space of the tubes 51 is separated from the unfiltrate chamber 49 impermeable to fluids. A tube end 52 of the tubes 51 slightly protrude from the access openings 53. Each of the protruding tube ends 52 of the tubes 51 is closed by a plug 55 that is visible in FIG. 1, whilst the opposite tube ends 52 are open. As is also depicted in FIG. 1, the tubes 51 extend parallel to each other as well as horizontal and laterally beside the pipe 41 that forms the outlet. A magnetic rod 57 may be inserted into and retrieved from each of the open tube ends 52 of pipes 51. Said magnetic rods 57, also called magnetic cores, are made up in the usual manner of a group of consecutive permanent magnets 59 (see FIG. 4) and are provided at one end with a spherical handhold 61 to be able to easily insert and retrieve the magnetic rods 57 from the respective tube 51.

During the filtration process the tubes 51 are located directly in the inflow section of unfiltrate supplied via inlet 47. Due to the magnetic force generated by the permanent magnets 59 of the magnetic rods 57, which are located inside the tubes 51, ferromagnetic particles are deposited on the outside of the tubes 51 so that pre-scalping takes place within the housing section located below the filter elements 5 before the unfiltrate rises to the filter cartridge where the filtration process takes place from the outside of the filter medium 33 to the inner filter cavity 46, which forms the filtrate side. For discharging the particles that were deposited on the tubes 51, the magnetic rods 57 are pulled out of the tubes 51. Due to the resulting removal of the magnetic force the deposited particles drop from the tube 51 to the base 19 of the bottom part 17. Besides the tube 41 that forms the discharge line for the filtrate, there is a particle outlet 63 (not shown) at the base 19 of the bottom part 17, which opens outlet 63 into an open position if a discharge of particles that has accumulated on the base 19 of the bottom part 17 needs to be carried out. This may simply be achieved by a flushing process in which unfiltrate, which flows in under system pressure via inlet 47, flushes the particles out through the opened outlet 63. In this instance it is preferable that the filtrate outlet 42 on tube 41 is closed so as to apply full system pressure in the flushing process. Since the tubes 51 are in the flow path of the unfiltrate coming from the inlet 47, any particles that may still adhere to the tubes 51 despite the absence of magnetic force, are carried away by the flow and thus discharged.

The FIGS. 3 to 5 depict a second exemplary embodiment of the filter device according to the invention, which differs from the first described exemplary embodiment only by a modified design of the housing part below the element seat 21. Analog to the first exemplary embodiment, the element seat 21 for the filter cartridge is attached above the tube 41 that forms the outlet, which in turn, like the tube 41 in the first exemplary embodiment, is fixed via webs 45 that extend in radial direction to the side wall of the housing. In contrast to the first exemplary embodiment the tube 51 does not extend coaxially to base 19 of bottom part 17 but is angled via an elbow 65 towards the filtrate outlet 42 by forming part of the same. Said filtrate outlet 42 is disposed on the side wall of the housing in the section between the element seat 21 and the tubes 51.

Located on the side opposite to outlet 42 is the unfiltrate inlet 47 which, compared to the filtrate outlet 42 is arranged slightly below the same. With the filtrate outlet 42 in a lateral position, the central section of the base 19 of the bottom part 17 is free for the coaxially arranged particle outlet 63. The tubes 51, which form the casings for the magnetic rods 57, are disposed slightly below the unfiltrate inlet 47 in the same way as in the first exemplary embodiment at a distance from each other, extending parallel and horizontal (see FIG. 5).

The functionality of the second exemplary embodiment corresponds in this design with the first exemplary embodiment, that is, the discharge of particles accumulated on tubes 51 may take place through flushing them out via the particle outlet 63 with the magnetic rods 57 removed. Whilst in both exemplary embodiments the tubes 51, which serve as casings for the magnetic rods 57, are closed by means of plugs 55 at one tube end 52 at the same housing side, the plugs 55 may be omitted so that magnetic rods 57 may be inserted or removed from any of the housing sides, whichever is better accessible in the installation. It is also possible that one tube 51 is closed on one housing side and the other tube 51 is closed on the other housing side. It is furthermore possible to provide a different number of tubes 51 as casings for a corresponding number of magnetic rods 57.

Claims

1. A filter device for fluids, comprising a housing (1) that accommodates at least one filter element (5), wherein housing (1) is provided with an inlet (47) for the supply of fluid to be cleaned to an unfiltrate chamber (49) of housing (1), wherein said unfiltrate chamber (49) is separated from a filtrate chamber (46) of housing (1) through the filter medium (33) of the respective filter element (5), wherein said filtrate chamber (46) is provided with an outlet (42) for filtrate, and a magnetic field-generating device (57) that is disposed within the unfiltrate chamber (49) and that is provided with an adhering surface (51) for ferromagnetic particles that are deposited there through magnetic force, which is formed through at least one casing (51) that surrounds the associated magnetic field-generating device (57), which extends from at least one opening (53) in the housing wall into the unfiltrate chamber (49) and in which the respective magnetic field-generating device (57) is moveably accommodated in such a way that it may be inserted and at least partially retracted again from the casing (51), characterised in that the respective casing (51) extends outside the respective filter element (5) inside the unfiltrate chamber (49) parallel to inlet (47) and transverse to the outlet (42), and that the unfiltrate chamber (49) encloses at least partially the outlet (42) at the point of the transition to the filtrate chamber (46).

2. The filter device according to claim 1, characterised in that the housing (1), at least in operation, extends along a vertical axis (3), which is comprised of at least two housing sections (7, 13, 15) of which the lower housing section (15) is provided with the inlet (47) and the outlet (42) as well as the respective magnetic field-generating device (57), and that the other housing sections (7, 13) serve to accommodate at least one filter element (5).

3. The filter device according to claim 1, characterised in that the bottom of the lower housing section (15) is closed and is provided with at least one openable outlet (63) for particles in such a way that, with a preferably closed filtrate outlet (42), the unfiltrate flowing in via the inlet (47) flushes off the particles collected by the respective magnetic field-generating device (57) from said device (57) and/or cleans the lower housing section (15) from contaminating particles.

4. The filter device according to claim 1, characterised in that at both sides of the filtrate outlet (42) and arranged at the same level are two parallel to each other oriented magnetic field-generating devices (57) with their casings (51), which extend at least partially, preferably fully, through the lower housing section (15).

5. The filter device according to claim 1, characterised in that the respective magnetic field-generating device (57) is comprised of a magnetic rod (57) formed through a group of permanent magnets (59), wherein said magnetic rod (57) is moveable inside a tubular casing (51) and is accessible at one end of the tubular casing for handling purposes.

6. The filter device according to claim 1, characterised in that more than one tubular casing (51) for a respective magnetic rod (57) is provided.

7. The filter device according to claim 1, characterised in that the lower housing section (15) is provided with a bottom part (17) that forms the bottom-end closing means, the base of which forms the lower closing means of the unfiltrate chamber (49), which extends along the outside of the filter medium (33) of the respective filter element (5) upwards, which is disposed in an axial distance from the base (19) of the bottom part (17), and that at least one tubular casing (51) extends in horizontal direction through the part of the unfiltrate chamber (49) between the base (19) of the bottom part (17) and the filter element (5).

8. The filter device according to claim 1, characterised in that on an element seat (21), which establishes the axial distance of the respective filter element (5) from the base (19) of the bottom part (17), a fluid connection (27, 43) is provided between the inner, hollow space (46) of the filter element (5), which during the filtration process forms the filtrate chamber, and an outlet line (41) for filtrate as part of the outlet (42), wherein a tubular casing (51) each extends through the unfiltrate chamber (49) on both sides of the outlet line (41) at a distance from the base (19) of the bottom part (17).

9. The filter device according to claim 1, characterised in that the outlet line (41) extends coaxial to the vertical axis (3) from the element seat (21) to the filtrate outlet (42) located at the base (19) of the bottom part (17), wherein besides the filtrate outlet (42) an outlet (63) is provided on the base (19) of the bottom part (17) for the ferromagnetic particles that have dropped from the respective casing (51).

10. The filter device according to claim 1, characterised in that the outlet line (41) extends from the element seat (21) to the filtrate outlet (42) located on the side wall of the housing (1), wherein at the base (19) of the bottom part (17), coaxial to the vertical axis (3), the outlet (63) for the ferromagnetic particles, which have dropped from the respective casing (51), is provided.

11. The filter device according to claim 1, characterised in that casings are provided in form of tubes (51) that extend from one housing side wall to another housing side wall, wherein said tubes (51) are preferably closed at one tube end (51) and provide at the other tube end (52) access for a moveable magnetic rod (57) each.

12. The filter device according to claim 1, characterised in that the magnetic rods (57), when inserted into the casings (51), extend up to a preferably closed end of the tube (52), and protrude with an end section in form of a handhold (61) at another end of the tube (52) to enable manual operation.