US2319599A - Method for refining used crankcase oil - Google Patents

Description

May 18, 1943 w. D. HARRIS 9 METHOD FOR REFINING USED CRANK CASE OILS Filed may 15. 1942 Patented May 18, 1943 l hNiTE METHOD FOR REFI'NING 'USED CRANKCASE OIL William D. Harris, Kansas City, Mo. Application May 15, 1942,'serial No. 443,030

2 claims.A I(ci. 19t-1s) This invention relates to a method for rendering available for further use in engines, crank case oil which has become contaminated to an extent which ordinarily would render it a waste product. It has been demonstrated by the pres.

ent inventor that the valuable lubricating properties of oil are not destroyed after ordinary use in an engine, and in fact it has been proved repeatedly that such used oil ldisplays a greater stability than it possessed when it was newly proe duced from the refinery. This is explained by the action of the engine in supplementing the original rening process by breaking down the unstable constituents remaining in, newly rened oil through the combined effects of heat and mechanical agitation. It will follow therefore, that if the contaminating constituents of the used oil are removed, the reclaimed oil will'be superior in at least some respects to freshly rened oil.

Methods for reflning'used oil have been proposed previously in the United States- Letters Patent of Aycock and Harris, No. 1,707,671,

granted on April 2, 1929, and Patrick, No.l

1,750,350, granted on Marchll, 1930; and apparatus for carrying out such methods has .been

In the methods employed in the prior art, oil in the still is heated to a relatively 'high temperature, and when the distillation is complete, this l heat is entirely wasted. In accordance with this' invention, when the oil is drawn from the still, it

' is brought into heat exchange reiationshipwitn a new batch of oil'to be rened, thereby preheating the new batch with a consequent saving of time and expense. u

The elements of an apparatus to carry out the steps ofmy method are interconnected by suitable piping and valves so as to facilitate travel of the oil through the system with a minimum of equipment and handling, and to permit cleansing ofthe parts by the circulation of uid from one receptacle to another, merely by the operation of a few valves. The manner of achieving the foregoing objects will be more clearly understood by referring to the accompanying' drawing'which is hereunto annexed and is s part of this speciiication.

The single ligureis a somewhat schematic eledescribed in United States Letters Patent of Hary vation partly brokenaway, showing an apparatus l capable of performing the present invention, al-

though it is recognized that various forms of apparatus may .be employed, therefore I only show one which has been demonstratedin` practice to be eiicientforthepurposeintended. The still I0, supported in a suitable frame I2, comprises an outer shell I4 and an inner shell it suitably spaced from the outer onel vfor insulating purposes. The inner shell is constructed to withstand relatively high internal and external pressures. The still is provided with an inlet opening I8, and an outlet opening 2li surmounted by a dome having an' inner wall 22 and an outer wall 24 spaced therefrom by a ilange 26. The dome is covered by a cap 28, having suitable threads 30 for connection with a fitting 32 to which a safety valve 34 and a distillate tube 36 are connected. Through suitable ttings, the

opposite end of the distillate pipe is connected t0 the upper end of a condenser coil 38, supported in acondenser tank 40. The lower end of the coil 38 is connected through a pipe 42 and gage glass 44, with a condensate or dilution tank 46.

Cooling water for the condenser is supplied from a suitable source through a valve 48 and pipe 50 'to the inlet opening 52 at the lower end of the condenser tank 40, whereupon it passes in countercurrent heat exchange relationship with the coil 3B and emerges through an outlet port 54 to a water pump 56 through a pipe 58. The pump 56 discharges through an outlet 60 to a conveniently located sewer connection. The suction side of the pump l5l is connected through a pipe 62, stop valve 64 and check valve 66 to the upper portion 0f the dilution tank 46 so that by proper manipulation of the valves, the dilution tank and still can be subjected to a partial' vacuum.

The dilution tank is supported upon a bracket -68 projecting from the frame I2, and may be` 'I6l arranged to form a cartridge and depending from the cap 28. One or more electric heating elements 'I6 are tted through the still wall to serve as the source of heat. Each element is enclosed within a casing 80 which is successively coated with nickel and chromium and highly polished to resist corrosion and facilitate clean-` ing. The still is also provided with a clean-out opening 82 which is normally closed lby a cover 84. Other nttings include a thermometer 86 to indicate still temperatures, a drain cock or air in a branched line.

vent 88 in the pipe line 42 between thecondenser coil and the dilution tank, a drain cock 90 for vthe dilution tank itself, a pressure gage 92 in vinsulating material |04. 'I'he bottom of the contact vessel is provided with an outlet opening |06, which through suitable piping |08 and a stop valve ||0, is connected with the intake side of a pump |2. Another opening ||4 is provided near the bottom of the contact vessel,

the lower end of a heat exchange coil 8 supported within a heat exchange andmixing tank |20. 'I'he upper end of the heat-exchange coil ||8 is connected through a nipple |22, valve |24, four-way fitting |26 and valve |28 with an opening |30 formed nearer the top of the contact vessel 98. The lower branch of the four-way tting |26 isconnected through a suitable pipe line |32, a 'l'.-tting |34, and a four-way itting |36, with the delivery side of the pump ||2. The pipe line |32 is provided with an intermediate branch pipeA |38 which, throughl a stop valve |40, feeds a retort washer nozzle |42 pass- 'ing through the cover 84. The upper branch of the four-way tting |26 is connected with a pipe |44, containing a stop valve |46, terminating One branch is connected through a stop valve |48 with apipe |50 leading to an opening |52 at'the'bottom of the mixing which connects it by a length of pipe l||6 with sludge` will settle and the oil will be clear of the carbon particles.

Assuming that all valves and cocks of the apparatus have been closed, the valve'48 will be opened and circulation begun through the condenser tank 40 and the pipe 68 to the pump 66 and discharge through the outlet 60 to the sewer. The valve 64 is also opened so as to establish communication between the pump and the dilution tank 46, condenser coil 38 and stillltl, thereby reducing the still pressure to a sub- `atmospheric value.

The oil to be treated is transferred to the mixing tank preferably, so as to cover the heat exchange coil ||8 and the agitator |62 set in opera-tion. To fifty gallons of such oil there is added 20 to 22 pounds-of a sulfuric acid treated clay such as RetroL a well known product of the Filtrol Corporation. 'I'his clay serves to restore the original color to the oil, particularly at elevated temperatures. After these materialshave been thoroughly mixed, lthe bottom oi' the mixing tank |20 is placed in communication with the still I0 byl opening the valve |48,`whereupon the vacuum created by the punip 56 will elevate the mixture intothe still. The valve will then be closed and current will be supplied to the heating element or elements 18. The mixing tank |20 will then be supplied with a new batchof oil' togbe treated in accordance .with steps to .b e'described subsequently.

As the temperature in the still rises, some water will probably'be distilled'ofl, and by maintaining tank |20; the other branch includes a pipe |54,

which is in .turn branched to connect with the y still inlet opening |8 through a pipe |56 on the one hand, and through a stop valve |58 to av contact vessel feed pipe |60, onthe other. An agitator 62 is suitably clamped on the wall of the mixing tank |20, with its shaft |64 carrying blades at its lowerend.

. vA by-pass 64 is connected in the line |08 intermediate the contact'vessel and the valve ||0, which, through a stop valve |66, communicates with the T |34. 'I'he pump delivery line is provided-with a pressure gage |68, which may be connected at the fourway fitting |36. The upper branch of the four-way tting' |36 is connected throughla stop valve |10 with the inlet of a-illter a relatively slight vacuum, all of the moisture vcan be removed without experiencing excessive foaming. When rthe still temperature reaches about 8251-F., thedegree of vacuum should be increased gradually byproperly manipulating the valves, andl l1' it appears from the 888e 818.56 u that part of thefoil itself is passing to the dilu' tion. tank, the cock`88 can be opened to v ent the press |12. 'I'he outlet of the press'is connected through a stop valve |14 with a filler pipe |16, Y and .through a stop valve |18 ahd pipe line |80 with a nozzle |82 located above the contact vessel 'Ihe used oil to be refined by the present proc-v ess should be treated first with sulfuric acidin an open vessel. Particularly heavy oil may rel thereby clearing this pipe line of any obstrucquire thinning with kerosene if the -best results.

' gallon of acid t'o fty gallons of oil. I'he addi? tion of acid and agitation should be continued jhowever until the carbon particles become sepa-` rated as distinct specks about the size of a pin head or larger and the oil between the particles is in a clear condition. The thus treated oil is thenpermitted to stand for a period ranging from six to eighteen hours,- during which the acid Then the valves cock -The product remaining in the still requires .ble neutralizing agent system to an extent necessary to correct Athis condition. Bycareful observation of the gagel glass, it is lpossible to obtain a maximum degree of vacuum in the system by the time and still temperature reaches'about 425 F., depending upon the desired viscosity of the end product. After the necessary heat has been supplied, the circuiti'to the heater is opened, yet the flow of condensing water! may be continued for a brief period- However. when all of the distillate to be removedhasbeen condensed, the valve 48 will be closed, which lwill of course, stop the action of the pump 66.: At this point, the-valves |24- and |46 between. the still inlet and. the contact vessel port ||4 may be openedV for a moment for the purpose ofsucking air. into the stillI and tions. The vacuum in the system is then broken by opening the vent 88 and at this time, the dilution tank46`may be drained by opening the some further treatment with reagents. which is carried out in the .contact vessel 98. Into this vessel there is deposited for each fty gallons of oil being treated, about 8 pounds of a clay of the type vof 200 mesh fullers earth, one such product `being known commercially as vReiinoilite Compound #1, and about 1/2- pound of an oil insolusuch as the material sold oon the open market as F. C. D. X.

|46 and |24 are opened to per-fr., mit oil to now from the still into the heat exf change coil I8, wherein heat is transferred from when the oil level in the tank drops.

the hot oil to the new batch in the mixing tank. The agitator |62 will be set in operation at this time so as to mix the new batch of oil with 20y to 22 pounds of the -Retro1" clay alreadyreferred to, which is described in trade-mark registration No. 304,074 as a chemically treated colloidal clay adapted for use as a decolorizing, bleaching, filtering, purifying and absorbing medium.

The hot oil owing through the coil ||8 will pass through the pipe ||6 into the contact vessel 98 where it encounters the treating agents previously placed therein. When all of the oil has owed from the still, which can be determined by the height of o il in the contact vessel 98 or byopening the valve 28, the valves |06A and |24 will be closed and the valve |28 opened.

nozzle |82 ,is sufciently clear. the valve |18 will be closed and the valve l|14 opened, so that the completely refined oil will be delivered through the pipe |16 to suitable containers. In the event `oi leakage in the press, the pipe line |83 from the bottom of the press to the intake side of the pump is provided. which may be `connected through a stop valve for breaking and establishing now.

The foregoing process represents a preferredV form to utilize the present invention, but it is to be understood that the various elements de- The-valve ||0 in the, suction line |08 is also opened and operation of the pump ||2 isl started. Oil is then drawn from the bottom of the vessel 98 through pipe |08, valve H0, pump ||2, and returned to the contact vessel through pipef|32 and valve |28. When this circulation has been established, valve |40 leading to the still lis opened and valve |28 is closed. Then valve |58 is opened so that the hot; oil flushing through the still will remove any loose composition which may have settled therein and cause it to` ow into the 'contact vessel. 'I'he valve |24 leading to the heat exchange coil ||8 is next opened and the valve |40 closed. The circulation is now from the bottom of the contact vessel, through the pump and coil, and back into the contact vessel. When the stillhas ceased draining through the pipe |60,

the valve |58 will be closed.

The water pump 56 is again started by opening the valve 48, and when a suiiicient vacuum has been established, the valve |48 is opened to draw the new batch of oil from the mixing tank into the still. The agitator |62 will be stopped When all Yof the oil has been drawn from thetank |20 into the still, the valve |48 is closed and the distillation process will proceed as before. The valve 24 is then closed and the valve |28 opened so that circulation from the contactA vessel to the pump and back to the contact vessel will be re established,.and during all of this time, the distilled oil is 4being cooled in preparation for its passage through the lter press |12.

The valve |10 leading to the lter press and the valve |18 leading therefrom arenext opened so that oil from the bottom of the contact vessel passes through the pump, part of it passing Ithrough the lter press, valve |18, pipe Y|80 and nozzle |82 to the contact vessel, the remainder through the pipe |32' and valve 28 to the contact vessel. Thus vit will. be seen, that by adjusting the valve |28, the pressure of the oil applied to the lter press can be regulated rather readily. When the ltered oil discharged from the scribed are not to be construed as limitations except Where they are set forth in the appended claims.

Having described my invention what I regard y through a conduit into said still by the vacuum, y

vaporizing the diluents from the oil in said still. after said diluents have been vaporized, causing the Vacuum to draw air through said conduit'to cleanse the same, breaking thevacuum in said still, drawing oi the re-rei-lned oil from said still to a contact vessel, cooling said re-reiined oil on its Way to said contact vessel by passing it in heat-exchange relation with a batch of oil to be re-rened, then circulatingy said oil repeatedly in a cyclic path from said contact vessel in heat exchange relation to saidv batch of oil and back to said contact vessel, by-passinga portion of said oil from said cyclic path and discharging it into vthe bottom of said still under pump pressure to remove any deposit in said still, vdischarging said ydeposit; and the by-passed portion of the oil from'the still and returning it to the cyclic path.

2.' Process of re-rening of used oil comprising the following steps: creating a vacuum in a still, causing a body of oil to be treated which is under atmospheric pressure to be drawn through a conduit into said still bythe vacuum, Vaporizing the diluents from the oil in said still, breaking the vacuum in said-still, drawing off the re-refined oil from said still to a contact vessel, cooling said re-reiined oil on its way to said contact vessel by passingvit in heat-exchange relation with a batch of oil to be re-rened, thencirculating said oil repeatedly in a cyclic path from said contact vessel in heat exchange relation to 'said batch of oil and back to said'contact vessel,

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