JPH07194909A - Filter element for liquid - Google Patents

Abstract

PURPOSE: To provide a filter element for liquid assuring permanent degassing without any means to be connected to a filtration element like a sleeve or a protected opening. CONSTITUTION: The filter element for the liquid has an outer casing (10) in which a central tubular body (13) is arranged. A filter medium (14) is placed between the casing and the tubular body. The liquid passes through an opening in an upper end plate (11), enters the medium and the filtered liquid comes out of the medium 14 through an opening in a lower end plate (12). What is fitted to the lower part of the central tubular body (13) is further another tubular body (17) through which the filtered liquid passes to flow into the upper part of the central tubular body 13. Furthermore, the upper end of the other tubular body (17) is coupled by a wall (18) to the central tubular body 13 and the air passing through the filter medium 14 gathers in a dead zone (20) delineated between the tubular bodies. An air delivery opening (19) formed by the wall (18) lets the air pass through a filtration fuel flowing in the central tubular body 13 in terms of the controlled quantity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a filter element for a liquid filter of the type inserted between a container and a suction pump.

[0002]

BACKGROUND OF THE INVENTION Fluid flow is induced through a filter during suction by a pump and the pressure between the pump and the filter is less than the pressure between the container and the filter.

The filter element forming the essential component of the filter is constituted by a filter medium, usually paper, which acts to prevent particles that may be suspended in the liquid in the container from damaging the suction pump. To be done.

Gas and air from the vessel circulate with the liquid in variable proportions and appear in the form of bubbles or as emulsions. The intrinsic properties of the filtration medium, in particular its pore size, the nature of the liquid, its viscosity and its flow rate, are some parameters that influence the pressure head loss in the region of the filter medium. The air or gas is liable to be stopped by the filtration medium, regardless of whether the liquid is flowing or is stopped, and an air pocket is formed that finally passes through the filtration medium following changes in the suction pressure of the pump.
The sudden flow of air towards the pump may cause difficulties to the pump or its use during start-up.

Various means exist for ensuring a permanent degassing of the liquid flowing through the filter.

Some of these means are provided for housing the filter element in the casing of the filter assembly and for mounting it on the liquid outlet tube, the porous sleeve having a pressure drop which is less than the pressure drop of the filter medium of the filter element. . Air is progressively evacuated by this sleeve, thus ensuring a permanent degassing.

However, these means partly bypass the non-filtrated liquid towards the filtered liquid, ie the filtrate.

In another means having a construction similar to that of the above means, a small opening in the filter assembly casing, protected by another filtration medium and connected to the outlet pipe, progressively discharges gas and is permanent. Guarantees good degassing.

These two cited means partially bypass the non-filtrate towards the filtrate without passing through the filtration medium.

Another measure known from French patent application No. 91.06726 ensures a permanent venting through an opening arranged in the region of the filtration medium.

[0011]

SUMMARY OF THE INVENTION The present invention guarantees a permanent degassing without any means of connection to the filter element, such as a sleeve or a protected opening, ie in the simplest possible way. To aim.

[0012]

To this end, the invention consists of a tube around which a filter medium, through which the liquid to be filtered passes, is arranged, said tube partially passing through said filter medium. After that, the air carried with the liquid to be filtered collects in the dead zone and through which the air in the dead zone flows in a controlled amount into the liquid filtered by the filter medium. A filter element for a liquid is provided, which defines an air discharge opening capable of being.

The filter media may be made from one or more strips, eg paper, which are wound together such that the media are of zigzag shape in cross section and fixed together at their upper and lower adjacent edges. .

The openings ensure a permanent degassing of the liquid passing through the filtration medium without passing unfiltered liquid into the filtered liquid.

In a special embodiment, the central tube is defined by two concentric tubes of different lengths, one of which opens inside the other and a dead zone between the two tubes. A constructed and vented opening is formed in one wall connecting the two concentric tubes.

In another embodiment, the central tube is defined by two concentric tubes that both open outside the filtering element and the vent opening penetrates the wall of the inner tube and the dead zone of one. It is limited by the annular space between the inner wall of the tube and the outer wall of the other tube.

In another embodiment, the filtration medium is superposed around a central tube through which the vent hole is penetrated and the dead zone is limited by the surface of the tube and the fold edge of the filter element. To be done.

The present invention is better understood from the accompanying drawings in which various embodiments of filtration media elements are shown.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the element comprises an outer casing 10 of hollow cylindrical shape having end plates 11, 12 at opposite ends thereof. One of the end plates may be integrally formed with the outer casing and the other end plate may be secured to the outer casing by edge wrapping once the filter media as described is in place. Each end plate has a central opening through which the tube 13 extends. Upper end plate 11
Has a series of inlet holes (not shown) through which liquid enters the element and the lower end plate 12 has a series of outlet holes or slots (not shown) through which the liquid flows through the element. You can get out.

Located in the space between the tube 13 and the inner surface of the casing is a filter medium 14 and in the embodiment shown in FIG. 1 this is at least two lengths wound around the tube 13. It consists of Sano Filter Paper.
At their upper and lower edges, the lengths of the paper are fixed together by an adhesive so as to form a filter medium which is zigzag in cross section. The medium thus formed has an inlet pocket 15 opening into an inlet hole formed in the end plate 11 and an outer pocket 16 opening into an outlet hole or slot formed in the end plate 12. The inner and outer folds of the medium are fixed to the tube and casing in a liquid-tight manner by means of an adhesive.

In use of the elements, the elements are clamped between upper and lower housing parts (not shown), which parts form the tube unit 1 so as to form a filter unit.
They are fixed together by bolts passing through 3. The upper housing portion defines a sealing edge against the upper edge of the casing 10 and an associated insert that rests in sealing engagement with the inner surface of the tube 13. Housing part is upper end plate 1
1 defines a liquid inlet connection opening into the space above and it also defines a liquid outlet connection extending through the spigot and in communication with the interior of the tube 13. The lower housing part defines a sealing edge against the lower end edge of the casing 10 and it defines a space or trough whereby liquid exiting the exit hole of the end plate 12 is below the tube 13. It is possible to flow at the end and to further tubes as described.

As shown in FIG. 1, in the lower part of the tube body 13, there is arranged yet another tube body 17 having a smaller diameter and projecting downwardly below the lower end of the tube body 13. It The annular partition wall 18 and the upper end of the tubular body 17 and the tubular body 1
It is a small air discharge opening 19 that extends between the inner surface of 3 and the wall.

In use, the filter unit is inserted between the fuel container and the fuel pump of the fuel system of an internal combustion engine. Solid contaminants are retained in the inlet pocket 15 and air tends to collect in the inlet pocket, but eventually through the filter paper and through the outlet pocket and the lower plate 1
It is carried by the fuel flow through the two exit holes or slots. Air attempts to flow upwardly into the annular dead zone 20 defined between the tubes 17 and 13, while the fuel is
Through the pipe body 13. The air in the dead space 20 is forced to exit the dead space in a controlled manner through the small openings 19 as a steady stream of small bubbles, whereas the air tries to flow into the dead space as large bubbles, The bubbles may reverse the operation of the pump when they are allowed to flow to the pump. The small bubble flow does not reverse pump operation.

In the arrangement shown in FIG. 2, the open upper end plate 11A extends inwardly around the tube 17A so that the dead field 20A extends to the height of the element. Tube 17
The upper end of A extends beyond the upper end of plate 11A and is in communication with the liquid outlet connection of the upper housing part. Further, one or more air discharge openings 19A are formed in the wall of the tubular body 17A. While the tube 17A is part of the filter element, it can be integral with the upper housing part. In this case, the upper end plate 11A is the tubular body 1.
An opening is provided to allow 7 to pass through. Liquid flows from the filter media through the openings in lower end plate 12A.

The filter element shown in FIG. 3 has an outer perforated casing 10B which is fixed by wrapping around the upper and lower end plates 11B, 12B. The upper plate is a central tube 1 whose lower end is spaced from the end plate 12B.
It has a central opening that opens to 3B. The end plates, except the central opening of the upper plate, have no holes or slots. The filter medium 14B has a zigzag shape and is a tube of filter paper which is folded along its length and fixed to the end plates by an adhesive. The inner folded edge of the filter medium is spaced from the perimeter of the tube 13B so as to form a dead space 20B, allowing air passing through the paper to collect in the dead space and an air discharge opening. 19
B is formed in the tubular body 13B. The fuel to be filtered flows through the openings in the casing and the air that collects in the dead space 20B flows through the openings as a steady stream of small bubbles.

[0026]

As mentioned above, the present invention provides a liquid filter element comprising a tube around which a filter medium through which the liquid to be filtered passes is arranged, said tube being partially said. After passing through the filter medium, the air carried by the liquid to be filtered gathers in the dead zone and communicates therewith and through which the air in the dead zone is controlled in the liquid filtered by the filter medium. Provides a liquid filter element that ensures a permanent venting without requiring a means to be connected to the filter element in the simplest possible way, as it is configured to define an air discharge opening that can flow in large quantities can do.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing an example of a filter element according to the present invention.

2 is a sectional side view showing a modified example of the element shown in FIG. 1. FIG.

FIG. 3 is a cross-sectional side view showing another example of a filter element according to the present invention.

[Explanation of symbols]

 10 Outer casing 10B Outer casing 11 End plate 11A Upper end plate 11B Upper end plate 12 End plate 12A Lower end plate 12B Lower end plate 13 Tubular body 13B Tubular body 14 Filter medium (filtration medium) 14B Filter medium 17 Still other Tube body 17A Still another tube body 19 Air discharge opening 19A Air discharge opening 19B Air discharge opening 20 Dead world (dead space) 20A Dead world (dead space) 20B Dead world

Claims (5)

[Claims] 1. A liquid filter element comprising a tube (13, 13B) around which a filter medium (14, 14B) through which the liquid to be filtered passes is arranged, said tube being partly. A dead zone (20, 20A, 20B) where the air carried with the liquid to be filtered after passing through the filter medium collects and the air in the dead zone is in communication with and through the dead zone. A filter element for a liquid, characterized in that it defines an air discharge opening (19, 19A, 19B) that can flow in a controlled amount into the liquid filtered by. 2. A further tube body (17, 17A) arranged in the first mentioned tube body (13), said further tube body (17, 17A) containing said filtered liquid. The liquid filter element of claim 1, wherein the liquid is received from a medium and the dead space is defined between the tubes. 3. The further tube (17, 17A) extends downwardly below the first mentioned tube and the air discharge opening (19) extends the upper end of the further tube. Liquid filter according to claim 2, characterized in that it is formed in the wall (18) interconnecting with the inner surface of the first-mentioned tube at a position intermediate the end of the first-mentioned tube. element. 4. The further tube (17, 17A) extends beyond the opposite end of the first-mentioned tube (13) and the air discharge opening (19A) of the further tube. Liquid filter element according to claim 2, characterized in that it is formed in a wall. 5. The air discharge opening (19B) is formed in the wall of the tube (13) and the dead field (20B) is an inner boundary between the outer wall of the tube and the filter medium (14B). Liquid filter element according to claim 1, characterized in that it is defined between a wall and a wall.