DE202008002927U1 - Liquid filter, in particular for fuel - Google Patents

Abstract

Liquid filter, in particular for fuel, preferably diesel filter, with an annular main filter element (5) and a main filter element (5) axially upstream, annular coalescer element (4) in a filter housing (2), with a central tube (3) for closing or Discharge of liquid, wherein the main filter element (5) and the coalescing element (4) are to flow in the radial direction, characterized in that axially between the main filter element (5) and coalescer element (4) has a radially projecting collision collar (12) for collecting deposited water droplets is arranged and that the impact collar (12) is fixedly connected to the central tube (3).

Description

Technical area

The The invention relates to a liquid filter, in particular for fuel, according to the preamble of claim 1.

State of the art

In the WO 2004/082804 A1 a fuel filter system is described which, in addition to the main filter element embodied as a particle filter, comprises a coalescer element as pre-filter unit, which is connected upstream of the main filter element and has the function of combining water droplets in the fuel into larger droplets. The present as a dispersion fuel-water mixture is for this purpose first passed through the coalescing element, in which very finely divided water droplets are collected into larger droplets. The coalescer element and the main filter element are each of annular design and enclose a central channel which serves for the axial discharge of the purified fuel. The fluid to be filtered is directed to the inside of the coalescer element and flows through the coalescer element radially from the inside to the outside, wherein the larger water droplets are deposited downstream of the coalescer on the inside of the filter housing. The actual filtration then takes place in the main filter element, which is flowed through by the fuel radially from outside to inside.

Disclosure of the invention

From Based on this prior art, the invention has the object on the basis of providing a liquid filter in which Effectively dispersing water droplets can be deposited in a fluid.

These Task is according to the invention with the features of claim 1 solved. The subclaims give appropriate training.

Of the Liquid filters according to the invention, which is in particular a fuel filter for internal combustion engines, is preferably a diesel filter, has a main filter element and a main filter element axially upstream coalescing element in a filter housing. The two filter elements are each ring-shaped and around a central Center tube laid, usually for the supply or discharge of liquid serves. Both the main filter element and the coalescer element are flowed through in the radial direction, preferably in counter set directions, where basically also a rectified Flow is considered.

Between the main filter element and the axially adjacent Coalescer element is a radially protruding impact collar arranged to collect deposited water droplets. The impact collar, which is firmly connected to the central tube and in particular forms with this a one-piece or one-piece component, serves for the separation of larger water droplets from the fuel mist, which in the flow direction the front lying coalescer element has passed. In the coalescer element smaller water droplets become larger droplets merged, but without already separating them. This means that on the exit side of the coalescer element the entire liquid mixture consisting of the dispersion of usually fuel or oil and water droplets, still the same overall ratio between these two Contains liquids. However, since the water content to larger water droplets in the coalescer element has merged, the water content of the liquid mixture be deposited better and more efficiently. This is done in facilitated and improved manner on the radially projecting impact collar, which is located axially between the coalescer element and the main filter element.

To flows through the introduction of the liquid to be purified this first the coalescer element in the radial direction, preferably radially from the inside to the outside. In connection it will be the larger water droplets deposited, in particular on the impact collar, the remaining Main fluid, so usually the fuel or the oil, for further filtration of the main filter element is supplied and advantageously this radially from flows inward through the outside. In the main filter element, which is preferably designed as a particle filter, finds a Filtration of the main liquid instead, and there are impurities filtered out. The purified liquid is subsequently derived axially over the center tube.

The one-piece design of the impact collar and center tube facilitates the assembly of the liquid filter on the one hand, on the other hand, this also improves the stability. The deposition of the water droplets can take place on both flanks or end faces of the impact collar, for example, by axially overflowing from the outlet side of the coalescing element to the inflow side of the main filter element, some of the coalesced water droplets strike the immediately facing end side of the impact collar. Another part is directed to the opposite end face of the impact collar by the water droplets of the liquid mixture are deposited on the inflow side of the main filter element and then hit the immediately facing end face of the impact collar. This can be supported by a hydrophobic coating on the upstream side of the main filter element.

advantageously, is the liquid filter in an at least approximately built-in vertical operating position, so that the center tube runs vertically. In this mounting position is conveniently located the coalescer element below and the main filter element above, above the coalescer element. The introduction of the liquid mixture takes place preferably from below, but not via the central tube, but via an inflow annulus between the outer Lateral surface of the central tube and the radial inner side of the coalescer element. From there, the coalescer element becomes radial flows through from inside to outside, then the liquid mixture is in the annulus between the outside the coalescer element and the inside of the filter housing wall axially in the direction of the pipe or inflow side of the main filter element directed. Advantageously, the coalescer element and the main filter element the same outer diameter, so that under the condition of an axially constant cross-section the receiving space in the filter housing also a corresponding constant annulus for the axial overflow from the outside of the coalescer element to the outside the main filter element is possible.

Of the Advantage of the axially superposed filter elements with upper main filter element and lower coalescer element is also seen in the fact that the water droplets the fuel-water mixture, which is on the upstream side of the main filter element are deposited by the effect their weight is applied in the direction of the impact collar and be caught up in this. For improved derivation of the separated water from the impact collar, it is advantageous that at least one gutter branches off from the impact collar, which the diverted water into a water collection room. This water collection room is located, for example, at the bottom of the filter housing, from where the collected water can be discharged. The gutter expediently runs parallel to the axis and is located on the radial outside of the coalescing element. It can be held on a scaffold that in particular formed integrally with the impact collar and preferably enclosing the coalescer element radially. This scaffold additionally improves the stability of the usual made of a soft filter material coalescing element. The center tube, the collision collar, the gutter and the scaffold form according to an expedient embodiment a common, one-piece component.

Around the deposited on the outside of the main filter element To be able to collect water droplets effectively the impact collar expediently a radial outside and upwards curved edge, whereby a circumferential collecting channel is formed on the impact collar, from which the gutter branches off vertically downwards.

Brief description of the drawings

Further Advantages and expedient designs are the other claims, the description of the figures and to take the drawings. Show it:

1 a section through a fuel filter, with a central tube and an annular coalescing element placed around the central tube and an annular main filter element, between which a radially protruding collision collar for collecting separated water droplets is arranged,

2 the central tube, the collision collar and the coalescer element and the main filter element in a perspective individual representation.

In The figures are the same components with the same reference numerals.

Embodiments of the invention

At the in 1 shown liquid filter 1 it is a fuel filter, which is intended on the one hand for the separation of water droplets, which are dispersive in the fuel, and on the other hand, for the filtration of dirt particles. The fuel filter 1 consists of a cup-shaped filter housing 2 in which a plastic center tube 3 is taken, on the one hand serves as a support structure for the filter elements and the other for the discharge of the purified medium. On the center tube 3 are two annular filter elements 4 and 5 placed, which are flowed through radially in succession by the liquid to be cleaned. It is a coalescer element 4 which is adjacent to the ground 7 of the receiving space in the filter housing 2 is arranged, and a main filter element 5 , which is axially to the coalescing element 4 and is located above the coalescer element. The center tube 3 , the coalescer element 4 and the main filter element 5 have a common longitudinal axis 6 on.

The coalescer element 4 has coalescing function and serves to enrich the water in the fuel, which is distributed as fine water droplets in the fuel, and to merge into larger water droplets. For this, the mixture, as with the arrows 8th and 9 represented, via an inflow opening 11 axially in the receiving space in the fil tergehäuse 2 initiated. The mixture is with the arrows 8th and 9 wherein the reference numeral 8th the fuel fraction (solid line) and the reference numeral 9 denotes the proportion of water (dashed line). About the inlet opening 10 the fuel-water mixture flows 8th . 9 in an influx annulus 11 which is between the outside of the central tube 3 and the radial inside, which also represents the upstream side of the coalescing element 4 is arranged. The inflow annulus 11 extends axially over the length of the coalescer element 4 , From the inflow annulus 11 from the mixture of fuel and water flows through the coalescing element 4 radially from the inside to the outside. After emerging on the radially outer side of the coalescing element, the water fraction is brought together to form larger water droplets, wherein the coalescing element is constructed in such a way that neither a separation of the water fraction nor a filtration of the mixture of contaminants takes place.

In one piece with the center tube 3 is a radially protruding collision collar 12 formed, which has a greater radial extent than the coalescing element 4 and the filter element 5 Both have the same outer radius. The collision collar 12 has radially outward lying obliquely upwardly facing edge 13 on, thereby in close proximity to the outside of the main filter element 5 a horizontal, circumferential collecting channel 14 is formed. The collision collar 12 is located axially between the underlying coalescer element 4 and the overlying main filter element 5 , Both filter elements 4 . 5 border the front side directly to the impact collar 12 , which is an axial end or end disc for the elements 4 and 5 forms.

The collecting trough 14 is with a gutter 15 fluidly connected to a scaffold 16 is held and attached to the outer shell side of the coalescing element 4 vertically and thus axis-parallel to the longitudinal axis 6 extends downwards. About the gutter 15 gets in the collecting trough 14 Trapped water down to the bottom of the receiving space in the filter housing 2 passed, which forms a water collection room. From the ground, the collected water can be discharged.

The center tube 3 , the collision collar 12 , the gutter 15 and the scaffold 16 are advantageously designed as a one-piece component, which consists in particular of a plastic material. The scaffold 16 includes directly on the outside of the coalescer element 4 circumferential and the Coalescer element enclosing struts, which are possibly connected by vertical struts, but in any case of the gutter 15 which are held by the collecting trough 14 branches off and is formed integrally with this.

In operation of the liquid filter 1 becomes the fuel-water mixture, which is the coalescer element 4 has passed radially across the flow annulus between the outside of the coalescer element 4 or main filter element 5 and inside of the wall of the filter housing 2 directed axially upwards. In this case, the enlarged water droplets partly come into contact with the inner wall of the filter housing and also on the underside of the impact collar 12 and are deposited at the relevant point. The remaining portion flows axially further in the direction of the radially outer inflow side of the main filter element 5 which is advantageously coated with a hydrophobic material in order to prevent a radial flow through the main filter element of the water content. The water droplets are then on the upstream side of the main filter element 5 deposited and dripping down towards the impact collar 12 from where the water in the collecting trough 14 collected and over the gutter 15 to the ground 7 is derived. The freed of water content fuel flows radially from outside to inside through the main filter element 5 in which a filtration takes place.

At the radial inside of the main filter element 5 , which represents the clean side, is the center tube 3 with flow openings 17 provided over which the purified fuel into the interior of the central tube 3 from where an axial downwards discharge takes place. At the level of the coalescer element 4 has the central tube 3 no such flow openings, in this section is the center tube 3 formed flow-tight.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2004/082804 A1 [0002]

Claims (11)

Liquid filter, in particular for fuel, preferably a diesel filter, with an annular main filter element ( 5 ) and a main filter element ( 5 ) axially upstream, annular coalescing element ( 4 ) in a filter housing ( 2 ), with a central tube ( 3 ) for the supply or discharge of liquid, the main filter element ( 5 ) and the coalescer element ( 4 ) are to be flowed through in the radial direction, characterized in that axially between the main filter element ( 5 ) and coalescer element ( 4 ) a radially projecting impact collar ( 12 ) is arranged to catch deposited water droplets and that the impact collar ( 12 ) fixed to the central tube ( 3 ) connected is. Liquid filter according to claim 1, characterized in that the impact collar ( 12 ) in one piece with the central tube ( 3 ) is trained. Liquid filter according to claim 1 or 2, characterized in that in the impact collar ( 12 ) a collecting trough ( 14 ) is introduced. Liquid filter according to one of claims 1 to 3, characterized in that on the impact collar ( 12 ) a radially outward, upwardly curved edge ( 13 ) is arranged. Liquid filter according to one of claims 1 to 4, characterized in that at least one drainage channel ( 15 ) from the impact collar ( 12 ) branches, is to be passed over the separated water in a water collecting space. Liquid filter according to claim 5, characterized in that the gutter ( 15 ) on the outer surface of the coalescing element ( 4 ) runs. Liquid filter according to claim 5 or 6, characterized in that the water collecting space at the bottom of the filter housing ( 2 ) is formed. Liquid filter according to one of claims 5 to 7, characterized in that the gutter ( 15 ) on a scaffold ( 16 ), which is integral with the collision collar ( 12 ) is trained. Liquid filter according to one of claims 1 to 8, characterized by a vertical operating position with vertical central tube ( 3 ), wherein the upstream coalescer element ( 4 ) below and the main filter element ( 5 ) is at the top. Liquid filter according to one of claims 1 to 9, characterized in that the coalescing element ( 4 ) and the main filter element ( 5 ) have the same outer diameter. Liquid filter according to one of claims 1 to 10, characterized in that between the radial inside of the coalescing element ( 4 ) and the outer circumferential surface of the central tube ( 3 ) an inflow annulus ( 11 ), over which the liquid to be filtered the coalescer element ( 4 ) is to be supplied.