Patent Application
20100122955
This invention is directed to a method and system for filtering oil and petroleum products and more particularly for removing particles down to about 0.1 microns.
Methods and systems for filtering oil and petroleum products are known in the art. While these systems work for their intended purpose, these systems are not effective in removing small particles for filtrate recovery. Part of the reason is that the oil does not have an acceptable viscosity to permit the removal of small particles. Thus, a need exists in the art for a method and system that addresses these deficiencies.
An object of the present invention is to provide a filtering system that removes particles down to about 0.1 microns.
Another object of the present invention is to provide a system that utilizes a sintered module.
A still further objective of the present invention is to provide a system that optimizes the viscosity of the filtered material.
These and other objectives will be apparent to one of skill in the art based upon the following disclosure.
A filtering system having a feed tank and output line where the pressure of fluid is sensed within the line and the flow rate adjusted to maintain a selected pressure. The output line extends from the feed tank to a cell. The cell has a pump, flow meter, heater, and sintered or ceramic module. The module is connected to a filtrate tank via a filtrate line and permits fluid having particles of 0.1 microns to seep through to the filtrate line. Fluid having particles greater than 0.1 microns are released from the cell to a feed stock tank.
Referring to the Figures, the system 10 has a feed tank 12. The feed tank 12 contains used oil or petroleum. The feed tank is connected to an output line 14 that extends from the feed tank 12 to a cell 16, or plurality of cells. Operatively connected to the output line 14 is a flow control valve 18, an in-line filter 20, and a pressure sensor 22. Preferably, the in-line filter 20 is a rudimentary 5 micron in-line filter. The flow control valve 18 and the pressure sensor 22 are connected to a controller such that the controller 24 sends a signal to open or close the flow valve 18 based on a signal received from the pressure sensor 22. In this manner, a constant pressure in the output line 14 may be preselected and maintained by the controller 24.
Along the output line 14, and downstream from the pressure sensor 22, are a plurality of shut off valves 26. The shut off valves are normally in a closed position, and are opened to clean or discharge fluid from output line 14. When the shut off valve 26 is closed, flow is diverted from the output line to a cell input line 28.
The cell 16, has a shut off valve 30 that is normally opened except for cleaning or discharge, a pump 32, a flow meter 34, a heater 36, a module 38, and a flow control valve 40. Fluid flows from output line 14 to the pump 32, through the flow meter 34 and the heater 36, to the sintered module 38. Preferably, the sintered module has porous metal filter elements constructed of sintered titanium powder that has exceptional chemical and temperature resistance and can withstand repeated cycles such as the TPM Series Liquid Process Filters manufactured by Graver Technologies. The sintered module 38 is preferably porous at 0.1 micron to permit particles such as dirt, carbon, metallic fibers and the like to seep through to a filtrate line 42. Alternatively, the module is made of a ceramic material.
The fluid, with particles greater than 0.1 microns, flows to flow control valve 40. The flow meter 34 and flow control valve 40 are connected to the controller 24 such that the flow control valve 40 is opened and closed by the controller 24, based on a signal from the flow meter 34. When closed, or partially closed, the flow control valve 40 diverts all or some fluid back to pump 32 where the fluid is recirculated through the cell 16. To the extent that flow control valve 40 is open, or partially open, some or all fluid flows back to output line 14 downstream from shut off valve 26. From cell 16, fluid flows either to subsequent cells, where the process is repeated, to a feed stock tank 44, or back to feed tank 12.
The filtrate line 42 extends from module 38 to a filtrate recovery tank 46. The filtrate line has a flow sensor 48 that is connected to the controller 24. A shut off valve 50 is also connected to the filtrate line 42 and is normally open except for cleaning and discharge.
To optimize the filtering, the fluid should have a desirable viscosity. The viscosity of the fluid is dependent upon the rate of flow, the pressure, and the temperature of the fluid. Preferably, the pressure in lines 14, 28 and 42 should range between 28 to 40 PSI. The temperature of the fluid should range between 340 to 360 degrees F. without exceeding 360° F. The rate of flow should range between 1.5 to 3.2 lbs/hr per sq. ft. Optimally the flow rate should be between 1.8 and 2.3 lbs/hr per sq. ft.
In operation, the pressure, flow rate, and desired temperature are selected and input into the system. Once inputted, the system is activated such that fluid flows from feed tank 12 to cell 16. The pressure in line 14 is maintained at the selected rate based on a signal from pressure sensor 22 which controls flow valve 18 via controller 24. Within the cell, fluid having particles 0.1 microns or smaller are removed through the sintered module 38 to a filtrate tank 46 through a filtrate line 42. Fluid having particles greater than 0.1 microns recirculates within cell 16 until the fluid is released by flow valve 40 based on the rate of flow determined by the flow meter 34. Once released, fluid flows to other cells for subsequent filtering, to a stock feed tank 44, or back to feed tank 12.
Thus a method and system of filtering oil has been disclosed that at the very least meets all of the stated objectives.
