WO2001074470A1

WO2001074470A1 - Apparatus for cleaning and analyzing debris from oil filters

Info

Publication number: WO2001074470A1
Application number: PCT/CA2000/000349
Authority: WO
Inventors: Kenzie D. Macisaac; Kevin N. Goddard
Original assignee: Gastops Ltd.
Priority date: 2000-03-31
Filing date: 2000-03-31
Publication date: 2001-10-11
Also published as: AU2000235476A1

Abstract

An apparatus for cleaning used oil filters, detecting metallic particles, and collecting the filter debris is discussed. Fluid and air are forced out of the filter under pressure in the filter's reverse flow direction, dislodging debris trapped within the oil filter. This debris flows through an outlet in an oil filter housing under gravity through a metal particle sensor where any metallic particles are detected and counted. The fluid then flows into a debris strainer where all particles above a given size are retained. The solid debris is retained in this strainer and the fluid passes through into a reservoir. A pump re-circulates fluid from both the reservoir and the strainer.

Description

APPARATUS FOR CLEANING AND ANALYZING DEBRIS FROM OIL FILTERS

TECHNICAL FIELD The present invention relates to a cleaning apparatus for removing and analyzing debris from a used oil filter.

BACKGROUND ART

Systems for cleaning used oil filters have previously used aqueous solutions having combinations of various chemicals designed to remove used oil from these filters. However, these systems were ineffective in quickly removing all of the debris from the used oil filter.

U.S. Patent 5,542,442 "Used Oil Filter Cleaning System" issued to Gorman, Sr. proposed using pressurized water. This patent teaches cleaning an oil filter by reverse flushing the used oil filter; that is, passing water through the filter from the clean side of the filter to the dirty thereby pushing out trapped debris.

The apparatus in Gorman, Sr. suffers from the drawback that the debris collected from the filter is not separated and analyzed. Filter debris analysis can be a useful diagnostic tool in monitoring the condition of machines with pressurized lubrication systems, such as an engine. The wear debris contained in an oil filter provides a representative sample of the type and severity of wear that has occurred in the machine over the course of the filter's sen/ice life. However, the process of recovering this wear debris can be time consuming and difficult. The current process involves running a filter in an ultrasonic cleaning bath for several hours. The debris that settles at the bottom of a tank is collected for analysis. DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide an automated system for cleaning used oil filters that would recover debris from a filter.

It is also an object of the present invention to provide a system for cleaning and collecting debris from a used oil filter and reusing the fluid used for cleaning the filter.

It is also an object of the present invention to provide a system for quickly and easily removing wear debris from a used oil filter and analyzing that debris.

It is a further object of the present invention to provide a system for quantifying debris extracted from a used oil filter to gauge a machine's condition.

It is an additional object of the present invention to provide a system for classifying ferromagnetic and non-ferromagnetic debris from a used oil filter.

In accordance with one aspect of the present invention there is provided an oil filter cleaning system for cleaning a used oil filter with a cleaning fluid, said cleaning system comprising: means for forcing the cleaning fluid through the used oil filter under pressure in a reverse flow direction thereby dislodging debris trapped within the used oil filter in a discharge mixture; a particle sensor for detecting metallic particles in the discharge mixture; and means for straining the discharge mixture to remove and collect dislodged debris such that the strained discharge mixture is re-usable as the cleaning fluid.

In accordance with another aspect of the present invention there is provided an oil filter cleaning method for cleaning a used oil filter with a cleaning fluid, said method comprising: forcing the cleaning fluid through the used oil filter in a reverse flow direction dislodging debris trapped in the used oil filter in a discharge mixture; detecting metallic particles in the discharge mixture; and straining the discharge mixture to remove and collect the debris therefrom such that the strained discharge mixture may be reused as cleaning fluid.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a schematic diagram illustrating an oil filter debris recovery and analysis system according to an embodiment of the present invention; Fig. 2 is a schematic diagrams illustrating a magnetic separator of the oil filter debris and recovery system illustrated in Fig. 1 ; and Fig. 3 is a flow diagram of a method of removing debris from a used oil filter according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Fig. 1 shows an oil filter debris recovery and analysis system 50 according to an embodiment of the present invention. The oil filter debris recovery and analysis system 50 cleans used oil filters 1 and recovers debris by pumping fluid, though one of the apertures where oil normally exits the filter and out the sides where oil normally enters the filter. That is, the fluid is pumped from the clean side to the dirty side of the used oil filter 1.

Fluid is pumped from a reservoir 6 to the used oil filter 1 , held in filter housing 2 at the top of the system 50, where the fluid is used to clean the used oil filter 1. The pump 15, used for bringing the fluid from the reservoir 6 to the used oil filter 1 , is located at the bottom of the system 50. The outlet flow of the pump 15 can be controlled by a throttle valve or by a speed control device to accommodate washing different sizes of used oil filters 1.

An air supply fitting 16 is located at the side of the system 50 for allowing bursts of air to enter the system 50. An air pressure regulator 17 located at the air inlet governs the supply pressure for the system 50. The air pressure regulator 17 provides a compressed air supply to the system 50. A normally closed solenoid or pneumatically actuated air valve 18, located downstream from the regulator, is actuated by a timing device 21. The air valve 18 regulates the introduction of timed compressed air pulses into the inlet pipe 4. These pressurized air pulses are introduced at regular intervals in order to assist in dislodging debris from the filter, allowing it to be washed away by the fluid. The air pulses are introduced at timed intervals such that the used oil filter 1 is full of fluid and the burst of air helps speed the fluid through the filter 1.

Two check valves 20, one located directly after the pump 15 and one located directly after the air-valve 18, prevent back flow in the pipe of either air or fluid. The pump 15 and air valve 18 are electrically connected to the timing device 21 which is in turn connected to a power supply 22 via a switch.

Fluid pumped into the filter housing 2 via the inlet 4 passes through the used oil filter 1 and drains out through the bottom of the filter housing 2. A vent 5, located at the side of the filter housing 2, is connected to a line leading down to the reservoir 6, which is at atmospheric pressure to prevent fluid mist from being sprayed out of the unit during the wash cycle.

Fluid and debris flow out of the filter housing 2 by gravity unless the fluid level in the housing 2 has risen to the point where a float valve 29 is closed by the fluid level. A funnel 35 is attached to the bottom of the oil filter housing 2 to direct oil and debris toward a housing outlet 3. If the valve 29 is closed, then the housing vent 5 is sealed off and the compressed air flowing in through the filter 1 pressurizes the housing 2, forcing fluid through the outlet 3 at a higher flow rate. When the fluid level drops the float valve 29 opens, thereby venting the housing 2.

A magnetic separator 31 is located directly downstream of the filter housing 2. Fluid and debris that flow out of the filter housing 2 pass through an internal cavity 34 of the magnetic separator 31. The fluid and debris exit the magnetic separator 31 and enter a metal particle sensor 7 that detects and counts both ferromagnetic and non-ferromagnetic metal particles present in the fluid/debris mixture. The particle count data is output to a display at the front of the oil filter and debris recovery and analysis system 50. The display provides a visible indication of the number of metallic particles that have been detected.

The fluid passes from the metal particle sensor 7 into a fine mesh screen 9 in a screen housing 8 where debris from the used oil filter 1 is trapped. The screen housing 8 consists of a funnel shaped container suspended inside a lid 12 of the reservoir 6. The screen housing 8 is lined with a coarse wire mesh 11 to support the fine mesh screen 9. An annular clamping mechanism 10 is located at the top edge of the screen housing 8 to secure the fine mesh screen 9 against the screen housing 8 during operation. The fluid passes through the fine mesh screen 9 and the coarse wire mesh 11 and is sucked out of the screen housing 8 by the pump 15.

The cover 12 of the reservoir 6 is tray shaped with an outer lip and is perforated to allow fluid that overflows the screen housing 8 to drain into the reservoir 6. The reservoir 6 itself has a funnel shaped bottom end. The reservoir 6 is joined to the outlet at the bottom of the screen housing 8. The pump 15 inlet is connected to a joining line 52 that joins the reservoir 6 and the outlet of the screen housing 8 such that fluid is pumped from the reservoir 6 and the screen housing 8 simultaneously.

When the reservoir 6 is emptied by the pump 15, a float valve 13 located near the bottom of the reservoir 6 closes, sealing off the reservoir 6 and forcing the pump 15 to suck exclusively from the screen housing 8.

Directly downstream of the joining line 52 is a fine in-line filter 14 to filter out very fine debris that has been extracted from the used oil filter 1 and has not been trapped in the fine mesh screen 9. This ensures that the washing fluid remains clean as it is reused. When the wash cycle is complete, the debris extracted from the used oil filter 1 is contained in the fine mesh screen 9, which can be removed and replaced with a new screen element.

The used oil filter 1 is placed over an adapter fitting 23 that screws into the filter support 24. The adapter fitting 23 creates a seal at the bottom end of the used oil filter 1. A second adapter fitting 32 is attached to a turn screw 33 that is threaded through a housing lid 25. The purpose of the second adapter fitting 32 is to seal off the top aperture of the used oil filter 1. Pressure is applied by the turn screw 33 to ensure a tight seal at both ends of the filter 1. Different top and bottom adapters 23, 32 could be used to accommodate different filter designs.

The filter housing lid 25 threads into the top of the housing 2. A filter support 24 is suspended in the center of the filter housing 2 by four spokes, two of which are hollow. The filter support 24 has four holes into which the spokes are inserted, one of which 26 extends up through the top meeting up with a threaded hole into which the adapter 23 is inserted. One hollow spoke 26, extends into this hole and provides an inlet for fluid and air. Another spoke 27 inserted in the filter support 24 connects to the vent line 5 and a vent hole 28 on the bottom surface of the filter support 24. The tapered entrance of the vent hole 28 serves as a seat for the float valve 29.

Fig. 2 illustrates in detail the magnetic separator 31 shown in Fig. 1. The magnetic separator 31 consists of an internal cavity 36 with the flow diffuser 34 that spreads the fluid and debris over a large flat area. One of the flat walls of the cavity 36 is made of a thin non-magnetic material 37 against which a flat powerful magnet 38 is placed. The magnet 38 can be turned on or off or be of the permanent type attached to a hinge 39 so that it can be placed against the flow cavity 36 to trap ferromagnetic particles and then pulled away to release them using an actuator 40. The magnetic separator 31 traps and holds all ferromagnetic particles that pass through the cavity 36 until the wash cycle is complete and all non-ferromagnetic debris has been captured in the screen 9.

Fig.3 illustrates a method of removing and recovering debris from a used oil filter 60 according to an embodiment of the present invention. A cleaning solution is forced through a used oil filter 62 in a reverse flow direction. This dislodges debris trapped within the used oil filter and creates a discharge mixture. Air pulses at predetermined intervals are forced through the used oil filter 64 in a reverse flow direction. This speeds the flow of cleaning fluid through the used oil filter. An enclosed housing covering the used oil filter is pressurized to increase flow of the discharge fluid that leaves the enclosed housing 66. Ferromagnetic metallic particles are separated from the discharge mixture 68. This allows a count of both ferromagnetic metallic particles and non-ferromagnetic metallic particles to be performed when metallic particles are sensed in the discharge mixture 70. The results of the particle count are output to a display 72. The debris is then removed from the discharge mixture and collected by straining the discharge mixture 74. The collected debris can be further analyzed 76 by other laboratory instruments external to the used oil filter recovery and analysis system.

The cleaning fluid used in the oil filter debris and recovery system can be either oil or some solvent. Any used oil brought into the system will be mixed with the oil used to clean the filter. Oil is used because it is one of the least hazardous fluids that can be used to clean a filter and can be easily disposed of when it is too dirty to use.

INDUSTRIAL APPLICABILITY

The present invention as described above in the exemplary embodiments applies to the industrial field of cleaning used oil filters.

Claims

CLAIMS:

1. An oil filter cleaning system (50) for cleaning a used oil filter (1) with a cleaning fluid, said cleaning system (50) characterized by: means (15, 17) for forcing the cleaning fluid through the used oil filter

(1) under pressure in a reverse flow direction thereby dislodging debris trapped within the used oil filter (1) in a discharge mixture; a particle sensor (7) for detecting metallic particles in the discharge mixture; and means (9, 14) for straining the discharge mixture to remove and collect dislodged debris such that the strained discharge mixture is re-usable as the cleaning fluid.

2. The cleaning system (50) according to claim 1 further characterized by a magnetic separator (31) upstream from the particle sensor (7) for separating ferromagnetic metallic particles from the discharge mixture.

3. The cleaning system (50) according to claim 2 wherein the particle sensor (7) retains a count of the number of ferromagnetic and non- ferromagnetic metallic particles in the discharge mixture.

4. The cleaning system (50) according to claim 1 further characterized by a closed oil filter housing (2) having means (23, 32) for securely holding the used oil filter (1) during cleaning.

5. The cleaning system (50) according to claim 4 wherein the means (23, 32) for securely holding the used oil filter (1) can accommodate used oil filters (1) of varying designs.

6. The cleaning system (50) according to claim 4 wherein the closed oil filter housing (2) further includes pressurization means (29) for pressurizing the closed oil filter housing (2) to increase flow of the discharge fluid that leaves the closed oil filter housing (2).

7. The cleaning system (50) according to claim 1 further characterized by a reservoir (6) for holding cleaning fluid, the reservoir (6) being connected to the means (15, 17) for forcing cleaning fluid through the used oil filter (1).

8. The cleaning system (50) according to claim 7 wherein the means (15, 17) for forcing the cleaning fluid through the used oil filter (1) draws cleaning fluid from the reservoir (6) and the means for straining (9, 14).

9. The cleaning system (50) according to claim 8 further characterized by means (13) for causing the means (15, 17) for forcing the cleaning fluid through the used oil filter (1) to stop drawing cleaning fluid from the reservoir (6) when a level of cleaning fluid in the reservoir (6) falls below a predetermined level.

10. The cleaning system (50) according to claim 1 wherein the means (15, 17) for forcing the cleaning fluid through the used oil filter (1) comprises means (17) for applying air pulses to the used oil filter (1) in a reverse flow direction to speed the flow of cleaning fluid through the used oil filter (1).

11. An oil filter cleaning method (60) for cleaning a used oil filter (1) with a cleaning fluid, said method (60) characterized by the steps of: forcing the cleaning fluid through the used oil filter (1) in a reverse flow direction dislodging debris trapped in the used oil filter (1) in a discharge mixture (62); detecting metallic particles in the discharge mixture (70); and straining the discharge mixture (74) to remove and collect the debris therefrom such that the strained discharge mixture may be reused as cleaning fluid.

12. The cleaning method (60) according to claim 11 further characterized by the step of forcing air pulses through the used oil filter (1) in a reverse flow direction (64) to speed the flow of cleaning fluid through the used oil filter (1).

13. The cleaning method (60) according to claim 11 further characterized by the step of separating ferromagnetic metallic particles from the discharge mixture (68).

14. The cleaning method according to claim 13 further characterized by the step of counting the number of ferromagnetic and non-ferromagnetic metallic particles in the discharge mixture (70, 72).

15. The cleaning method according to claim 11 wherein the used oil filter (1) is held in an enclosed housing (2) during cleaning and the cleaning method (60) further characterized by the step of pressurizing the enclosed housing (2) to increase flow of the discharge fluid (66) that leaves the enclosed housing (2).