MXPA99003134A - Filter assembly - Google Patents

Abstract

The two part fuel filter assembly (300) for filtering and removing water from fuel under pressure includes an upper portion (302), an inner sleeve member, an annular space between an outer housing of the upper portion (302) and the inner sleeve member, and filtering medium (322). The filtering medium (322) is positioned within the sleeve member.

Description

FILTER ASSEMBLY BACKGROUND OF THE INVENTION Field of the Invention The invention relates to a fuel filter, and more particularly, to a filter for use with diesel fuel, and in particular, to a fuel filter that separates water.

Brief Description of the Prior Art In the United States Patent No.4, 986, 907, it is established that the design of the filter is such that the interior of the fuel flow conduit whose arrangement is perpendicular with respect to a longitudinal axis of the orifice. of entry allows a first impact of the fuel entering the apparatus through the inlet. When flowing out of the inner pipe 30, the fuel hits the metal plate 50 (vertically sectioned in Figure 3), which moves diametrically and also substantially longitudinally around the interior of the cylinder. While the patent diesel filter does reliable work in water removal, it is an expensive structure and does not remove trace portions of water. It does not completely separate the water if the water accumulates as a great stagnation. Also, trapped air interferes with the process of water separation.

According to the patent the fuel leaving the pipe 30 and striking against the plate is projected in a centrifugal manner to create a turbulence that initially facilitates the separation of its components such as water, sulfur, sulfuric acid, etc., which at their higher specific weight in relation to the fuel (diesel) they tend to precipitate towards the lower surface of the cylinder 10. The concept of using centrifugal force to facilitate the separation of fuel / water, was also found in the United States Patent No. 4,780,203, in which the fuel flows obliquely downwards to generate a rotating flow that promotes the separation of the densest water fraction from the fuel. An upturned nozzle is * provided to collect droplets of water dripping to the outer surface of the outlet duct.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages of the present disclosure will become more apparent when read with the specification and drawings, wherein: Figure 1 is a cross-sectional view of a filter assembly according to the present invention. Figure 2 is a schematic illustration of a filter medium.

Figure 3 is a cross-sectional view of an alternating filter assembly.

BRIEF DESCRIPTION OF THE INVENTION It has now been found that a fuel filter can be produced at a very low cost by scrupulously avoiding the turbulent flow found in prior art filters, such as 4,986,907 and 4,780,203. Additionally, it has been found that the present design can provide equivalent performance or even superior performance with a unit of smaller diameter. That is, the use of a diameter equivalent to that typically employed with the design of the '907 patent provides superior performance. In the design of the present invention, the water is completely removed regardless of the stagnant size of the water, until the contaminated chamber is filled. The fuel filter assembly for filtering and removing water from a fuel under pressure includes an outer housing, an inner sleeve member, an annular space between the outer housing and the inner sleeve member, and filter means for filtering the fuel . The filter means are placed inside the sleeve member. The fuel inlet is at an upper end of the outer housing and provides fluid flow between the outer housing and the inner sleeve. The fuel inlet and the annular space are positioned and sized to provide a substantially laminar, non-circumferential, downward flow. The inner sleeve member extends down to a position below the bottom of the filter means. The fuel that flows down and contaminants must rotate 180 degrees and flow up through the filter medium to the outlet. The denser components of slower movement are deposited in the accumulation chamber. The accumulation chamber is the region inside the lower end of the external housing, under the filter medium and the annular sleeve. The outlet valve provides a fluid drain for materials that accumulate in the accumulation chamber. The filtering means can be hydrophobic filter media which prevents the passage of water through the filter medium.

DETAILED DESCRIPTION OF THE INVENTION The construction and means of use of the filter medium are well known in the art, as seen for example in U.S. Patent No. 5,507,942. According to the '942 patent, to provide a constant level of the least possible restriction of fuel flow through the fuel filter assembly during the service life of the filter medium while using as little as possible of the filter medium, the filter means is housed vertically in the housing 12 so that the lower portions are first clogged before the fuel level rises and uses the unobstructed upper portions of the filter medium. A filter housing houses the filter medium which is folded back and forth in a circular fashion so that a hollow cylinder is formed. The filter medium, in the top view, has a star or brooch appearance in the form of a sun, which results from the folding of the filter medium. According to the '942 patent, the filter medium can be continuously rolled or wound around a vertical axis or reference cylinder to form a retention cylinder having substantially concentric layers of filter media positioned adjacent to each other. The filter medium can be manufactured from a paper-based material, although any other suitable material, such as glass fiber, plastic, etc., can be used to provide the proper filtering characteristics while also being combustible. for efficient disposal. In another embodiment, the filter means may be a hydrophobic filter means that prohibits the passage of water through the filter medium. This can also make it easier to prevent water from passing through the fuel filter assembly and affect engine performance or damage the engine's fuel injection mechanisms. The fuel filter means described in the '942 patent and other patents, can be easily employed in the filter of the present invention. The present invention departs from the structure and operation of prior art filters in that it provides laminar flow of fuel downstream along the cylindrical sleeve. By laminar flow it is implied that there is no turbulent flow of a viscous fluid in layers near a limit, such as that of the lubricating oil in the bearings. The turbulent flow causes dust particles and water to pass through a turbulent fuel stream during the separation stage. It is considered that the centrifugal forces found in the above filter structures will separate the dense materials from the light materials, but, unless the separate streams are maintained as discrete streams, re-entry occurs. In the present structure, the flow entry in the upper part of the filter does not produce a centrifugal action. Additionally, the annular space between the cylindrical sleeve and the inner wall of the housing has a cross-sectional area that is large enough to provide laminar flow. Additionally, the speed of the fuel flow is greatly reduced, thus improving the separate process. The dense water and the particular material is directed downwards along the sleeve. The change of direction of the rapid flow results in lighter materials, ie, fuel, to be pulled up more easily than dense water. The re-entry of the separated materials is not observed when the system is in use. The use of a transparent housing allows the user to see the flow patterns in the filter structure. It is observed that the air bubbles do not adversely affect the process of separation. Additionally, adding extremely large amounts of water to the fuel, for demonstration purposes, on the scale between 0.236 and 0.473 liters of water, for a one-quarter filter (30.48 cm in diameter), it did not adversely affect the operation of the system. The separation was immediate and complete. While in a system such as the one observed in the 4,986,907 patent, it can be seen passing the water through the system, particularly when air or very large amounts of water have entered, the present system seems not to be affected by air bubbles or the presence of a full accumulation chamber, provided that the water level is not above the point of return. It is estimated that a 30.48 cm diameter filter of the present invention would be at least equivalent to a 40.64 cm diameter filter of the design of the '907 patent. In U.S. Patent No. 4,780,203 it is recognized that the smaller droplets are more difficult to separate from the main stream, than the larger droplets. It is considered that this problem is due to the presence of fluids in a turbulent path that re-enters the smallest drops. This problem was not found with the filter of the present invention. It also seems that with a laminar flow environment the small drops of water or air come together, thus facilitating the separation process. The annular flow not only provides a change in flow direction, but critically, provides a change in flow velocity that is sufficient to allow contaminants in the fuel, eg, water and particles to separate or release from the fuel. diesel. By way of comparison, in document 4,986,907, a centrifugal flow is produced which generates a turbulent flow. The annular flow of the present invention is vertically downward around the filter, and then, vertically upwardly around and through the filter. The turbulent flow causes the water / particles to enter the fuel and works against the separation. The annular flow is laminar flow. The cross-sectional area of the annular region is substantially smaller than that of the interior of the flow. The change of the flow rate in combination with the change of direction of flow, achieves the separation of water / particles. The speed of the flow change is on the scale of about 1/20 to about 1/50, and preferably is on the scale from about 1/30 to about 1/40; The change in flow velocity is inversely proportional to the size of the cross-sectional area. The flow rate, typically in gallons per minute, to remain constant will experience changes in velocity with respect to the square area of transverse direction of the size of the flow cavity. When the cross sectional area is cut in half, the flow rate must be doubled to maintain a constant flow rate. The flow rate decreases from 1, the internal flow up to 1/20, the downward annular flow up to 1/50, the ascending annular flow, requires a cross-sectional area for each speed reduction. After the fuel reverses its downward annular flow, the flow velocity decreases due to the increase in additional area. The flow velocity in the vertical direction does not have the same critical level because separation has already occurred. The change in the direction of flow, by itself, can produce separation. The change in the flow velocity also produces the separation of water / contaminant from fuel. The combination optimizes the degree of separation that is achieved. In the optimal system, the separation can be 100%. The previous system minimizes or eliminates turbulent flow. Turbulent flow causes water or other separated particles to physically enter the fuel, working in this way against separation. The flow in the current system is maintaiparallel to the walls, to avoid turbulent flow. The turbulent centrifugal flow of the 4,986,907 patent is avoided. The flow is from a feed pipe of approximately 3.22 cm2 to a region between the outer wall of 12.7 cm internal diameter and the internal wall of 11.43 cm external diameter. The annular flow is therefore from a pipe 32.25 cm2 to an annular area of 96.75 cm2. The flow in the pollutant storage region increases to 419.25 cm2-. Gravitational forces are used to improve separation. The flow velocity after the upward rotation is determiby the annular space around the filter, between the filter and the annular tube (the inner ring), and is not narrowly critical. The internal annular cross-sectional area must be at least equal to the cross-sectional area of the inlet and outlet pipes. The separation takes place before and during the flow direction change. Therefore, the flow characteristics of the second ring need only be equal to the flow velocity in the rest of the system. The cross-sectional area of the inner ring is therefore at least equal to the cross-sectional area of the inlet and outlet pipes. A reduced cross sectional area would produce an undesirable restriction in the system. It should be noted that in document 4,986,907, the particles must pass through! Turbulent fluid that flows centrifugally. By way of comparison, the downflow in the present invention is laminar. Therefore, the particles move from a region of reduced laminar flow velocity within a collection region, an additionally reduced velocity area. In the 4,986,907 patent, the flow is within a turbulent region, towards a collection region and then upwards. The installation of the inverted filter would negate the operation of the filter, since the filter uses gravity to aid in separation. In an inverted flow installation, heavy particles (water and dirt) would try to flow against the direction of fuel flow and would therefore tend to re-enter. This would be comparable to the centrifugal turbulent flow in the '907 patent. Therefore, the entrance at the top achieves flow and separation assisted by gravity, descending. The upward flow of diesel fuel leaves the water / particles in the collection region. The terms upper and lower, which refer to the entrance in the upper part and the drainage of the ball valve in the lower part, are relative to the gravity flow. That is, the flow of gravity is from top to bottom. Water and dirt or other contaminants in collected solid particles can be discharged through the draining of the G-ball valve. The filter is a common paper filter, currently in use with diesel fuel engines. The draining of the ball valve is a commercially available device and is not of a critical design. In the '907 patent, the area entry interferes with the water-fuel separation. In the present device, air is not a major problem, due to the absence of turbulent flow. Additionally, the present design provides accumulated air to the flow up and out. Mounting the filter below the height of the gas tank allows the accumulated air to be vented to the gas tank. The modality of Figure 3 illustrates a two-part filter, generally indicated as 300. The unit. 302, is essentially identical to the corresponding portions of the filter of Figure 2. The lower portion 304 of the filter 300 differs from the lower portion of the filter of Figure 2, in that it contains a concave plate 312, which may be referred to as a false background. The concave plate 312 serves as a partition wall between the separated water and the fuel flowing or stored in the upper portion 302 of the filter 300. During the separation process, the diesel fuel, which is lighter than the water, flows up and out of the filter, through filter means 322. Water, which is lighter than diesel fuel, gravitates towards the bottom of the filter, passes through opening 314, into concave plate 312, and is housed within the lower water storage region 322 is defined as the concave plate 312 and the lower section 304 of the filter unit 300. The lower storage region 322 is provided with one or more vents, which allows the diesel fuel trapped in the water storage region 322, leaves the storage region and the water flows into the storage region. Ventilation 316 works by much in the same way that air vents work in commonly used liquid storage vessels. During the start-up period, the entire filter is filled with diesel fuel. When the fuel flow starts, the water is separated from the fuel, migrates downward by gravity, as indicated by arrow 318, and enters the water storage region 322 through the opening 314. The diesel fuel in the water storage region 322, leaves the storage region by means of ventilation 320, as indicated by arrow 320. A primary benefit derived from the separation of diesel fuel and the separated and stored water 320, is the prevention of re-entry of the stored water 320. The concave shape of the separating wall 312 is beneficial because the water flow is directed, or flows naturally, into the opening of the concave wall 312. The water storage region 322 may be provided with one or more sensors 308 and 310. When the water level reaches the sensor, a signal is provided to indicate that water drainage is required. Obviously, the draining may be automatic, and the water drain valve 340 may be an electrically operated valve. The automatic opening of the drain valve 340 causes the stored water to leave the filter 300. The discharged water can be stored in a separator wall vessel, not shown. The electrically operated valve 340 may be a synchronizer that remains open for a period sufficient to drain the water from the water storage region. Preferably, the synchronizer is set to close the valve before full water drainage, so that the fuel is not drained from the system. It is noted that the water storage region operates when the filter is in a vertical position. However, if the filter is used in a vehicle that will be subjected to cross-country use, the filter must be capable of operating at some phase angle. This condition can be found, even more easily, when the filter is used in boats.

On trucks, or other vehicles operated on the road, it would be unusual to subject the vehicle to a step from side to side, the vehicle could be required to climb or descend at a passing angle. In this case, the use of a front and rear water sensor would be sufficient. In a boat, the passage from side to side can be expected and the sensors are preferably a pair of sensors placed side by side, in relation to the boat. In fast boats, it may be desirable to use four sensors to accommodate the vessel's lateral passage during acceleration. Since many other modifications and changes will be apparent to those skilled in the art to suit particular operation requirements and environments, the invention is not considered limited to the example selected for the purposes of description, and covers all changes and modifications that do not. they constitute separations from the true spirit and scope of this invention.

Claims (8)

1. A fuel filter assembly for filtering and removing water from a fuel under pressure comprising: an outer housing, an inner sleeve member, an annular space between the outer housing and the inner sleeve member, filter means for filtering the fuel, the filter means that are placed inside the sleeve member, a fuel inlet, the fuel inlet which is at the upper end of the outer housing and which provides fluid flow between the outer housing and the inner sleeve, the inlet of fuel and the annular space that is positioned and sized to provide a substantially laminar, non-circumferential, downward flow in the annular space, the inner sleeve member extending down to a position below the bottom of the filter means, a accumulation chamber, the accumulation chamber that is placed inside the lower end of the housing External force, external valve means, external valve means that provide fluid drainage for materials that accumulate in the accumulation chamber.

2. The fuel filter assembly of claim 1, wherein the filter means comprises a hydrophobic filter means that prevents the passage of water through the filter medium.

3. The fuel filter assembly of claim 1, wherein the filter means is manufactured entirely from combustible materials.

4. A fuel filter assembly for filtering and treating a volatile fuel under pressure comprising: an outer housing member, the outer housing member having an internal region, an annular sleeve member, the annular sleeve member that is placed within the outer housing, and which provides an annular fuel flow region between the annular sleeve and the outer housing member, fuel inlet means, the fuel inlet means providing access to the interior, means of exit of fuel, the fuel outlet means providing the fuel egress from the fuel filter system, the pollutant collection region, the contaminant collection region that is located at the bottom of the outer housing member, the water drainage means pollutant, the means of draining pollutant that provide the discharge of pollutants that they accumulate within the pollutant collection region, filter means for filtering the fuel, filter media housed in the housing, the interior of the annular sleeve member, the fuel inlet supplying the fuel under pressure between the external housing and the annular sleeve member, in a non-centrifugal, laminar flow, the annular sleeve member extending below the fuel filter means, whereby fuel flows downward in an annular flow region and upwardly within of the annular sleeve member and upwardly and inwardly through the filter means, and fuel outlet means, to provide an outlet for the fuel from the filter medium.

5. A liquid filter assembly for filtering and removing a first liquid from a second liquid under pressure comprising: an outer housing, a liquid inlet, a first liquid outlet, a second liquid outlet, an inner sleeve member , an annular space between the outer housing and the outer sleeve member, the annular space that is at least equal to the cross-sectional areas of the inlet and outlet, the liquid inlet that is at the upper end of the outer housing and which provides liquid flow between the outer housing and the inner sleeve, the liquid inlet and the annular space that is positioned and dimensioned to provide a substantially laminar, non-circumferential, downward flow in the annular space.

6. The liquid filter of claim 5, wherein the first liquid is water, and the second liquid is a liquid fuel, and further comprising filter means, the filter means that are positioned within the sleeve member, the limb inner sleeve extending down to a position below the bottom of the filter means, an accumulation chamber, the accumulation chamber which is positioned within the lower end of the external housing, the first liquid outlet providing fluid drainage for materials that accumulate in the accumulation chamber, the liquid inlet that provides substantially laminar, non-circumferential flow, descending into the annular space.

The fuel filter assembly of claim 6, wherein the filter means comprises a hydrophobic filter means which prevents the passage of water through the filter medium.

8. The method of filtering and removing a first liquid from a second liquid under pressure comprising the steps: passing a first liquid and a second liquid through a liquid inlet to an annular space between an external housing and an outer sleeve member , the liquid inlet at the upper end of the outer housing, subjecting the first liquid and the second liquid to a substantially laminar, non-circumferential, downward flow in the annular space.