FILTER APPARATUS

Abstract

A filter device for cleaning particulate contaminants from a fluid flow, comprising a plurality of filter elements (34, 60) which are accommodated in filter chambers (12, 14, 32) as components of a joint filter housing (10) and are grouped around a backwash device (20) having a piston accumulator (56) for receiving a backwash fluid, in the storage housing (64) of which piston accumulator a piston (57) is guided in a longitudinally movable manner, which, controlled by a pressure medium, passes on the backwash fluid stored in the storage housing (64) on to at least one filter element (60) to be backwashed for cleaning purposes via a backwash device (20), which also discharges the backwash fluid from the filter device, is characterized in that a specific filter element as a bypass filter element (34), which is selected from the plurality of filter elements (34, 60), exclusively removes particles after a changeover device (18) has been actuated, and the other filter elements (60) are excluded from this removal process.

Claims

1. A filter device for cleaning particulate contaminants from a fluid flow, comprising a plurality of filter elements (34, 60) which are accommodated in filter chambers (12, 14, 32) as components of a joint filter housing (10) and are grouped around a backwash device (20) having a piston accumulator (56) for receiving a backwash fluid, in the storage housing (64) of which piston accumulator a piston (57) is guided in a longitudinally movable manner, which, controlled by a pressure medium, passes on the backwash fluid stored in the storage housing (64) on to at least one filter element (60) to be backwashed for cleaning purposes via a backwash device (20), which also discharges the backwash fluid from the filter device, characterized in that a specific filter element as a bypass filter element (34), which is selected from the plurality of filter elements (34, 60), exclusively removes particles after a changeover device (18) has been actuated, and the other filter elements (60) are excluded from this removal process.

2. The filter device according to claim 1, characterized in that the changeover device (18) is also accommodated in the joint filter housing (10) and has a distribution device which, in its one switch position, bypassing the bypass filter element (34), supplies the other filter elements (60), insofar as they are not subject to backwashing, with unfiltered medium and discharges the filtrate and which, in a further switch position, bypassing these filter elements (60), supplies the bypass filter element (34) with unfiltered medium and discharges the filtrate.

3. The filter device according to claim 1, characterized in that the changeover device (18), designed as a changeover fitting, can be moved manually between the switch positions by means of a hand lever (26).

4. The filter device according to claim 1, characterized in that at least one filter element (60) from the plurality of filter elements (34, 60), including the bypass filter element (34, 60), can be backwashed by means of the backwash device (20).

5. The filter device according to claim 1, characterized in that the changeover device (18) has a spindle (25), which can be rotated in a spindle housing (24) as part of the filter housing (10) and which has two fluid channels (36, 38) separated from each other on the outer circumference, which are connected to a fluid inlet (28) of the filter housing (10) for the supply of unfiltered medium and are connected to a fluid outlet (30) for discharging filtrate, and that in one switch position of the changeover device (18) the two fluid channels (36, 38) are connected to the individual filter element (60) provided for filtration and in the other switch position to the bypass filter element (34).

6. The filter device according to claim 1, characterized in that two fluid ducts (52, 54) separated from each other are provided on an inner wall of the filter housing (10), relative to the position of the piston accumulator (56), within the filter housing (10), which fluid ducts (52, 54) at least partially encompass the piston accumulator (56) and which, in one switch position of the changeover device (18), are connected in a fluid-conveying manner to the assignable fluid channels (36, 38) in such a way that filtration is made possible using the filter element (60) provided for this purpose, which filter element (60) is flowed through from the outside to the inside for removing particles.

7. The filter device according to claim 1, characterized in that the backwash device (20) cleans the particle contamination from each filter element (60) provided for this purpose in counterflow to the direction of filtration, in that two backwash channels (69, 71) arranged opposite from each other are guided in the filter housing (18) in a fluid-conveying manner with the two opposite ends of the filter element (60) to be backwashed being displaceable in the filter housing, thereby shutting off the two fluid ducts (52, 54) for the filtration process.

8. The filter device according to claim 1, characterized in that the lower bottom ends of the individual filter elements (34, 60) are closed and have a fluid discharge duct (44, 62) at their upper end, which is closed off from the assignable filter chamber (12, 14, 32), which encloses the individual filter elements (34, 60) with a radial distance.

9. The filter device according to claim 1, characterized in that the piston accumulator (56) above its piston (57) has a filtrate space (67) for receiving filtrate from the filter device and a control space (61) below the piston for receiving compressed gas, which moves the piston (57) upwards thereby displacing the filtrate in the filtrate space (59), which cleans the filter element (60) from particle contamination from the inside to the outside via the upper backwash channel (69) and the fluid discharge duct (62) in the filter element (60).

10. The filter device according to claim 1, characterized in that the lower backwash channel (71) of the backwash device (20), connected to the filter chamber (32) of the filter element (60) to be backwashed, is used to remove the particle contamination from the filter device.

Description

[0025] In the Figures:

[0026] FIG. 1 shows a perspective oblique view of an exemplary embodiment of the filter device according to the invention;

[0027] FIG. 2 shows a top view of the filter device of FIG. 1 from above;

[0028] FIG. 3 shows a partially cut, perspective oblique view of the filter device of FIG. 1 to illustrate bypass mode;

[0029] FIG. 4 shows a partially cut, perspective oblique view of the filter device of FIG. 1 to illustrate filtration mode; and

[0030] FIG. 5 shows a partially cut, perspective oblique view of the filter device of FIG. 1 to illustrate backwash mode.

[0031] FIG. 1 shows an overall view of the filter device according to the invention having a filter housing 10, which has three filter chambers, a first filter chamber 12, a second filter chamber 14 and a third filter chamber 32 (see FIG. 2), a spindle housing 24, a main housing part 16 and a drive unit 22. A fluid inlet provided on the spindle housing 24 for the supply of fluids to be cleaned is designated by 28, and an outlet for discharging cleaned fluids is designated by 30. A filter element 34 (see FIG. 3), 60 (see FIG. 4) is inserted in every filter chamber 12, 14, 32. A central component of the filter device is a changeover device 18, which is enclosed by the spindle housing 24 and of which only an actuating device in form of a hand lever 26 is visible in FIG. 1. Further, a backwash device 20 is provided on the filter device, which backwash device is accommodated in the main housing part 16 and of which the drive unit 22 arranged above the main housing part 16 is visible in FIG. 1.

[0032] In the at least partly sectional illustrations of FIGS. 3, 4 and 5, bypass mode is illustrated in FIG. 3, filtration mode in FIG. 4 and backwash mode in FIG. 5. The top view of the filter device of FIG. 2 from above shows the filter chambers 12, 14, 32 and the spindle housing 24 arranged on a circular line such hat they concentrically encompass a hydraulic accumulator located therebetween in the main housing part 16. As FIGS. 4 and 5 show, a piston accumulator 56 forms the hydraulic accumulator.

[0033] FIG. 3 illustrates bypass mode, in which fluid flowing into the filter housing 10 at the fluid inlet 28 is purified at the bypass filter element 34 in the first filter chamber 12 and routed to the fluid outlet 30 as filtrate. The changeover device 18 formed as a changeover fitting can be shifted manually between the switch positions by means of the hand lever 26 and has a spindle 25 rotatably arranged in the spindle housing 24. In the switch position of the changeover device 18 shown in FIG. 3, the fluid channels 36, 38 formed on the spindle 25 are connected to the first filter chamber 12 in a fluid-conveying manner. In the first filter chamber 12, the cylindrical bypass filter element 34 is arranged in a holder 42 and has a closed bottom 40.

[0034] The unfiltered medium passes from the fluid inlet 28 to an inlet space 46 of the first filter chamber 12 via the first fluid channel 36 extending horizontally and formed in the spindle 25 and a first connecting piece 37 formed in the spindle housing 24, wherein the inlet space 46 radially encompasses the bypass filter element 34. In the exemplary embodiment shown, the bottom 40 of the bypass filter element 34 is spaced apart from the bottom of the first filter chamber 12, so that the part of the interior space of the first filter chamber 12 located below the bottom 40 also has to be assigned to the inlet space 46. The unfiltered medium flows from the inlet space 46 through the bypass filter element 34, is cleaned there and reaches a filter cavity 48. From the filter cavity 48 the filtrate reaches a fluid discharge duct 44 located above the holder 42 and further on the fluid outlet 30 via a second connector 39 formed in the spindle housing 24 and via the second fluid channel 38 formed in the spindle 25.

[0035] The first and the second connecting piece 37, 39 each have a channel width comparable to the fluid channels 36, 38 and differ in their fluid paths in that the first connecting piece 37 starting from the first fluid channel 36 drops at a step-like gradient towards the inlet space 46 and the second connecting piece 39 starting from the fluid discharge duct 44 drops at a step-like gradient towards the second fluid channel 38. The fluid routing shown in FIG. 3 is possible because the spindle housing 24 is arranged immediately adjacent to the first filter chamber 12 and is preferably formed integral therewith. This side-by-side arrangement is clearly visible in the plan view of FIG. 2. FIG. 2 further shows that the second and the third filter chamber 14, 32 and the spindle housing 24 are arranged equidistantly from each other on the main housing part 16 in relation to the axis of symmetry R (see FIG. 1) of the main housing part 16. The axis of symmetry R of the main housing part 16 is also the axis of rotation of an output shaft of the drive unit 22, for instance in the form of an electric motor.

[0036] The bypass filter element 34 and the filter element 60 arranged in the third filter chamber 32 (cf. FIG. 5) are each hollow cylindrical in shape, wherein a conically tapering shape is also feasible as an alternative to the cylindrical shape. The filter elements 34, 36 can be formed as filter cartridges. A metal fiber fleece, a dutch weave or a square mesh fabric is preferably used as the filter material. The filter element 60 used to remove the particulate contamination occurring during regular mode preferably has a filter material having a higher grade of filtration than that of the bypass filter element 34.

[0037] In filtration mode of the filter device shown in FIG. 4, the switch position of the changeover device 18 is selected such that, bypassing the bypass filter element 34, the other filter elements 60, provided they are not subject to backwashing, are supplied with unfiltered medium and the filtrate is discharged. In doing so, the hand lever 26, which is firmly connected to the spindle 25, is swiveled clockwise by approx. 1200 in plan view in relation to the bypass position shown in FIG. 2.

[0038] In the functional position of the filter device shown in FIG. 4, unfiltered medium flowing into the filter housing 10 at the fluid inlet 28 reaches a chamber 53 in the bottom of the main housing part 16 via the first fluid channel 36 and the first connecting piece 37 and a further inlet space 59 of the third filter chamber 32 via a first further connecting piece 58. A filter element 60 is arranged in the third filter chamber 32 comparable to the arrangement of the bypass filter element 34 in the first filter chamber 12 (see FIG. 3). The fluid flows in the radial direction from the further inlet space 49 through the filter element 60 and reaches a further fluid discharge duct 62 via a further filter cavity 61. The filtrate flows from the further fluid discharge duct 62 to a chamber 55 on the cover side in the main housing part 16 via a second further connecting piece 63 and to the fluid outlet 30 via the second connecting piece 39 and the second fluid channel 38.

[0039] A piston accumulator 56 is arranged coaxially to the axis of symmetry R in the main housing part 16, on the housing 64 of which piston accumulator 56 the bottom-side chamber 53 and the cover-side chamber 55 are separated from each other by a partition wall 65. On an inner wall of the filter housing 10 there are two fluid ducts 52, 54 which are separated from each other in relation to the position of the piston accumulator 56, which fluid ducts 52, 54 at least partially encompass the piston accumulator 56 and which are connected to the respective assignable fluid channels 36, 38 in the switch position of the changeover device 18 shown in FIG. 4.

[0040] The filter element 60 arranged in the third filter chamber 32 is backwashed in the functional position of the filter device shown in FIG. 5. The backwash device 20 comprises two washing arms 68, 70 formed on the piston accumulator 56, which are guided to the assigned filter chambers 12, 14, 32 by an assigned rotary movement of the piston accumulator 56. The washing arms 68, 70 block the two fluid ducts 52, 54 for a filtration process in the third filter chamber 32. In this way, fluid can be filtered using one filter element and the other filter element can be simultaneously backwashed. The interior space of the piston accumulator 56 is subdivided by a piston 57, which can be moved longitudinally in the storage housing 64, into a filtrate space 67 for receiving filtrate from the filter device and a control space 56 for receiving compressed gas. Filtrate flows from the chamber 55 on the cover end into the filtrate space 67 of the piston accumulator 56 via a filling bore 50, which is formed in the wall of the upper washing arm 68 and which is preferably stepped in diameter to form a narrow inlet opening, and fills this filtrate space 67, while the piston 57 of the piston accumulator 56 moves downwards into the position shown in FIG. 5.

[0041] The gas is stored in a gas tank 66, which is located adjacent to the second and third filter chambers 14, 32 on the filter housing 10, see FIG. 2. For backwashing, the piston 57 is driven upwards by feeding compressed gas into the control space 61, as illustrated by the arrow 72, to create a flow in the manner of a pressure surge from the filtrate located in the filtrate space 67. The pressure surge reaches the further filter cavity 61 via an upper backwash channel 69, which is predetermined by the upper washing arm 68, the second further connecting piece 63 and the further fluid discharge duct 62. When flowing through the filter element 60 from the inside to the outside, the particulate contamination adhering to the filter material is removed and the backwash fluid including the contaminants is discharged via the further inlet space 59 and a lower backwash channel 71 specified by the lower washing arm 70 into a valve-controlled backwash line 74 and in that way out of the filter device.