Used Oil Recycling and Pretreatment Filtration Assembly

Abstract

A filtration system suitable for recovering base stock from used lubricating oil and other applications passes feedstock over nano-filtration membranes in a serpentine flow. Pressure boosters installed in the openings separating consecutive stacks serve to restore lost pressure of the feedstock. As pretreatment a “knocking” non-blinding filter separates particulates from a feedstock by a knocking action that dislodges particulate matter which has come to rest on the screen. Further pretreatment includes a vacuum evaporator for flash evaporation of volatile components from a liquid and effecting the extraction of water and glycol from used engine lubricating oil. The liquid is heated or cooled when flowing over some of the surfaces to adjust for heat lost or acquired during exposure of the liquid surface to a gas or vacuum. Liquid moves on the surface of the discs under centrifugal force or a wiper blade guides the liquid as it moves over the support surface.

1 . A filtration system to produce a permeate from a feedstock comprising multiple permeable membrane support panels each carrying respective membranes, each support panel having a receiving space within to serve as a cavity for accepting permeate driven through the membranes by pressure applied to the feedstock and a permeate-receiving cavity outlet to drain-off permeate, wherein
 a) the multiple membrane support panels are mounted in a common pressure-containing vessel having a feedstock inlet and outlets for permeate and concentrate, and   b) the pressure vessel contains at least one pressure-sustaining separator plate positioned between at least two adjacent membrane support panels, the separator plate having a flow-through opening at one end to allow fluid to flow from one membrane support panel to the next.   
     
     
         2 . The filtration system as in  claim 1  wherein the at least two adjacent membrane support panels are positioned on opposite sides of the separator plate so as to reverse the direction of feedstock flow over the consecutive membrane support panels on either side of the separator plate. 
     
     
         3 . The filtration system as in  claim 1  wherein:
 a) the support panels comprise two permeable panels mounted back-to-back with two respective membranes located on their outer-facing surfaces, and 
 b) the two panels define between them the receiving space there within to serve as the cavity for accepting permeate driven through the two membranes by pressure applied to the feedstock, 
 
       thereby constituting “panel assemblies”. 
     
     
         4 . The filtration system as in  claim 3  wherein, between separator plates, groups of panel assemblies are arrayed in a parallel configuration so that feedstock will flow in the same direction on both sides of the panel assemblies within the group, collectively the panel assemblies in a group constituting a “stack” of panel assemblies separated by the separator plates. 
     
     
         5 . The filtration system as in  claim 4  wherein the pressure vessel contains three or more stacks of panel assemblies, each consecutive stack being separated from an adjacent stack of panel assemblies by a pressure-sustaining separator plate, each separator plate having a flow-through opening at one end to allow fluid to flow from one stack of panel assemblies to the next. 
     
     
         6 . A filtration system as in  claim 5  comprising a pressure booster mounted in at least one separator plate flow-through opening to restore lost pressure between consecutive stacks of panel assemblies. 
     
     
         7 . A filter system as in  claim 6  comprising pressure boosters respectively mounted in the flow-through openings in every other separator plate. 
     
     
         8 . A filter system as in  claim 7  comprising pressure boosters respectively mounted in the flow-through openings in every separator plate. 
     
     
         9 . A filter system as in  claim 6  wherein the pressure booster is actuated by an electric motor. 
     
     
         10 . A filter system as in  claim 7  wherein the pressure boosters are actuated by respective electric motors. 
     
     
         11 . A filter system as in  claim 8  wherein the pressure boosters are actuated by respective electric motors. 
     
     
         12 . A filter system as in  claim 6  wherein the pressure booster is actuated by a rotating shaft driven from outside the pressure vessel. 
     
     
         13 . A filtration system as in  claim 7  wherein the pressure boosters are actuated by a common rotating shaft driven from outside the pressure vessel. 
     
     
         14 . A filtration system as in  claim 8  wherein the pressure boosters are actuated by a common rotating shaft driven from outside the pressure vessel. 
     
     
         15 . A filtration system as in  claim 13  wherein the common shaft penetrates intervening separator plate through a pressure seal. 
     
     
         16 . A filtration system as in  claim 5  comprising respective frames within which each membrane panel assembly is mounted, the frames, when the membrane panel assemblies are combined to form stacks, serving as part of the walls of the pressure containment vessel, wherein the frames provide a manifold connected to the permeate outlets of the permeate receiving cavities of each membrane panel assembly for collection of permeate for delivery to an external storage vessel. 
     
     
         17 . A filtration system as in  claim 16  wherein separator plates interspersed between the stacks of panel assemblies and serving as part of the walls of the pressure containment vessel are respectively provided with conduits connected to the manifolds of the frames to receive and convey permeate out of the pressure containment vessel. 
     
     
         18 . A filtration system as in  claim 4  wherein the permeate-receiving cavity outlets of each panel assembly in a stack are connected to a stack manifold that is connected to deliver permeate to a back-pressure control valve having an associated pressure sensor and valve control system for establishing the pressure within the permeate-receiving cavity. 
     
     
         19 . A filtration system as in  claim 4  wherein the permeate-receiving cavity outlets of each panel assembly in a stack are connected to a stack manifold that is connected through passageways formed in a separator plate at the end of the stack to deliver permeate to a back-pressure control valve having an associated pressure sensor and valve control system for establishing the pressure within the permeate-receiving cavity. 
     
     
         20 . A “knocking” non-blinding filter for extracting a filtrate from a feedstock comprising:
 a. a resiliently supported frame in turn supporting a durable, permeable screen or mesh that is oriented at a flow-supporting downwardly inclined angle, 
 b. an entry region for receiving the feedstock at the upper end of the frame from which the feedstock will flow down the inclined screen to the base end of the frame, 
 c. a catching container positioned beneath the screen for capturing the filtrate passing through the screen, and 
 d. an actuator coupled to the frame to apply a force with a component for displacing the frame in a generally horizontal direction, or in a direction aligned with the upward incline of the screen, with a “knocking” action whereby the force applies a rapid onset of acceleration to the screen that assists in dislodging non-penetrating particulate material resting thereon. 
 
     
     
         21 . A filter as in  claim 20  a return displacement mechanism for causing the filter to thereafter return to its original location after the frame has been displaced by the knocking action. 
     
     
         22 . A filter as in  claim 20  wherein motion of the screen is cyclical and the actuator applies an acceleration to the screen at one stage in the cycle wherein the acceleration so applied is greater than the absolute value of any other acceleration or deceleration occurring during the cycle. 
     
     
         23 . A filter as in  claim 20  wherein the applied acceleration is at least 1.5 times the absolute value of any other acceleration or deceleration occurring during the cycle. 
     
     
         24 . A filter as in  claim 20  comprising an actuator coupled to the frame to generate the accelerating force, such actuator being selected from the following class:
 a) an electrical solenoid 
 b) a hammer carried on a rotating support 
 c) mechanical linkages coupled to a rotating drive 
 d) an off-center mass carried by a rotating drive. 
 
     
     
         25 . A filter as in  claim 21  wherein the return displacement mechanism comprises one or more springs or resilient elements to return the displaced screen to its original location. 
     
     
         26 . A filter as in  claim 20  wherein the filter is a filter of steel mesh. 
     
     
         27 . A filter as in  claim 26  wherein the filter is a stainless steel mesh with openings smaller than 200 microns. 
     
     
         28 . A filter as in  claim 20  wherein the force accelerating the screen achieves an acceleration of 0.3 g to 5 g over at least a short length of its travel. 
     
     
         29 . A filter as in  claim 20  wherein the force applied to the frame oscillates with a frequency of 1 per 5 seconds to 20 per second. 
     
     
         30 . A gas-liquid exchange interface apparatus for effecting chemical or physical exchanges between a gas and a liquid or evaporation of gas from the liquid comprising:
 a) a containment for maintaining inner components in a gas-tight, pressure controlled environment;   b) a liquid inlet to the containment for introducing the liquid into the containment;   c) a segmented, vertical cascade of support surfaces positioned within the containment in the form of a column of segments  220  wherein a first support surface within each segment is positioned:
 i) to receive the liquid from the liquid inlet onto a central region of the first support surface, and 
 ii) to allow the liquid, when present and so deposited, to flow radially outward from the central region to and beyond the periphery of the first support surface; and 
 iii) to expose liquid flowing over the first support surface for release of volatiles or for carrying-out a gas-liquid reaction; Liquid flowing over the second support surface is uncovered for exposure to release volatiles or carry-out a gas-liquid reaction. 
   d) each segment providing a peripheral receiving surface and transfer passageway to transfer such liquid leaving the first support surface for deposition onto a second support surface for further inward radial flow over such second support surface towards the central area of the second support surface;   e) a central opening in the central area of the second support surface positioned to direct the liquid onto the central region of the first support surface of the next consecutive segment,   f) a gas outlet on the containment for introducing or evacuating gases present therein or volatile components evaporated from the liquid,   g) a liquid outlet from the containment for evacuating a residual portion of the liquid,   h) a liquid distributor means within each segment for inducing liquid deposited on the central region of the first support surface to flow radially outward from the central region,   i) a liquid gathering means for the second surface to draw liquid towards the central region of the second support surface, and   j) a thermal control source positioned within at least some of the segments for heating or cooling the liquid passing over the second surface.   
     
     
         31 . An apparatus as in  claim 30  wherein the thermal control source is positioned between the first and second surfaces within the segments for heating or cooling the liquid passing over the second surface. 
     
     
         32 . An apparatus as in  claim 30  wherein the thermal control source comprises electrically insulated electrical resistance wires in thermal connection with the second support surface. 
     
     
         33 . An apparatus as in  claim 31  wherein the thermal control source comprises tubing in thermal connection with the second support surface for carrying a heat transfer fluid to either heat or cool the second surface and liquid flowing thereon, when present. 
     
     
         34 . An apparatus as in any one of  claim 30 ,  31 ,  32  or  33  comprising:
 a) a temperature sensor positioned within at least some of the segments having a thermal control source to detect the temperature of the liquid, when present, as it passes through the segment, and 
 b) a temperature controller coupled to the temperature sensor and connected for controlling the rate of delivery of heat transfer by the thermal source to such segments. 
 
     
     
         35 . An apparatus as  claim 34  wherein the controller operates to transfer a differing quantity of heat to at least one segment than to another segment in the column. 
     
     
         36 . An apparatus as  claim 34  wherein the controller operates to deliver greater heat to lower segments in the column to raise the temperature therein. 
     
     
         37 . A process of using the apparatus of  claim 34  wherein, by sensing the temperature of the liquid in at least two segments of the column while the liquid proceeds through the column the controller controls the rate of transfer of heat to or from the second surfaces of such segments to provide heat flow at different rates to the respective segments. 
     
     
         38 . An apparatus as in  claim 30  wherein within at least some of the segments the liquid distributor means comprises a rotatable central shaft having a central axis connected to the first support surface for rotating the first support surface within the containment and thereby inducing radial flow of the liquid when deposited thereon, 
     
     
         39 . An apparatus as  claim 38  wherein each segment comprises:
 a) the first support surface being in the form of a spinable disc with a circumferential perimeter, the discs in the respective segments being mounted on the rotatable central shaft, and 
 b) the peripheral receiving surface and transfer passageway include an upright circumferential liquid catching sidewall connected to and serving as an upright sidewall for the second surface and serving to deliver liquid to the second support surface. 
 
     
     
         40 . An apparatus as in  claim 38  or  39  wherein in at least some of the segments of the first support surface are perforated to allow fluid to pass there through and travel radially outwardly on the underside of such first support surface while being held in place by surface tension. 
     
     
         41 . An apparatus as in  claim 38  or  39  wherein in at least some of the segments the first support surface comprises a screen portion that is permeable to permit liquid to pass there through and travel radially outwardly on the underside of such surface while being held in place by surface tension. 
     
     
         42 . An apparatus as in  claim 41  wherein the first support surface is conically shaped and oriented to be opening upwardly so as to bias liquid to pass through the screen for outward travel on the underside of such surface. 
     
     
         43 . An apparatus as in  claim 30  wherein within at least some of the segments the liquid distributor means comprises a wiping blade mounted on a central rotating shaft having a central axis for rotating the wiping blade to sweep over the first support surface and induce outward radial flow of the liquid when deposited thereon. 
     
     
         44 . An apparatus as in  claim 30  wherein within at least some of the segments the liquid distributor means comprises a wiping blade mounted on a central rotating shaft having a central axis for rotating the wiping blade to sweep over the second support surface and induce inward radial flow of the liquid when deposited thereon. 
     
     
         45 . An apparatus as in  claim 38  wherein within at least some of the segments the liquid distributor means comprises a wiping blade mounted on the central rotating shaft for rotating the wiping blade to sweep over the second support surface and induce inward radial flow of the liquid when deposited thereon. 
     
     
         46 . An apparatus as in  claim 45  wherein the wiping blade is mounted on the central rotating shaft through a speed reducing connector. 
     
     
         47 . An apparatus as any one of  claim 44 ,  45  or  46  wherein the portions of the second support surface conveying the liquid towards its central region are downwardly inclined and generally conically formed to induce the inward radial flow of the liquid, when present, over the second support surface towards the central area of the second support surface. 
     
     
         48 . An apparatus as in  claim 30  in combination with a gas evacuation pump connected through the gas outlet to maintain the pressure controlled environment within the containment at a sub atmospheric pressure level. 
     
     
         49 . An apparatus as in  claim 30  wherein the containment comprises a gas inlet for injecting reaction gas or sweep gas into the containment. 
     
     
         50 . An apparatus as in  claim 30  wherein the containment comprises a liquid level sensor positioned to detect the level of liquid accumulated within the containment in combination with a liquid level controller connected thereto and further operatively connected to a liquid extraction pump for intermittent removal of liquid from the containment in accordance with the status of the liquid level in the containment.