US1997295A - Apparatus and process for re-refining waste lubricating oil - Google Patents

Description

(5, R. DUFFY April 9, 1935.

APPARATUS AND PROCESS FOR RE-REFINING WASTE LUBRICATING OIL Filed July 21, 1935 Patented 9,1935 R f t I v UNITED STATES PATENT i APPARATUS AND PRocEss FoR RE-REFIN N ING WASTE LUBRIGATING on.

George Richard Duffy, Medford, Mass assignor to Star Oil Refining Corporation, Boston, Mass.,- a. corporation of Arizona a Application July 21, 1933, Serial No. 681,480, 4ClaimS. (01. 196-16) This .invention relates to an apparatus and The still, furthermore, embodies thereinafurnace process for re-refiningwaste lubricating oil. 7 fi provided with a stack 5 within which is a'flue 6. The primary object of the invention is to pro- Any suitable form of fuel may beprovided for vide an improved apparatus and process by means the furnace 4 and the gases generated thereby 5 of which lubricating oils' which have been conare conducted outwardly from said furnace 5 terminated and diluted by previous use may be rethrough the flue 6. V V Y 7 refined and thereby reclaimed for subsequent lu- The mixture ofwaste' oil and clay 3 is fed into 7 bricating use. t the container 2 through an inlet pipe Leading Another object of the invention is to provide from the container 2 at the bottom thereof is an 10 an apparatus embodying therein an improved. outlet connection communicating with a plurality 10 means whereby the mixture of impure oil and of pipes 9 suitably arranged as in a'coil, orcomclay, utilized as a bleaching agentin this process, municating one withanother, and at i i may be agitated, circulated and preheated with- .the furnace d'beneath the container'2. The mixin the still to the end that the productive'capacture of oil and clay is withdrawn from the conity of a still of a given size will be'increased by tainer 2 and forced through the pipes '9 by means 15 reason of its greater heatingefiiciency; of a pump I Q, from which the mixture is forced Another objector the invention is'gto provide back mm the container through a p p said an apparatus and process in whichflu'e gases mixture being dischar e below the level f the from the furnace of the still are deoxidized and liquid within the container through a plurality utilized to produce a reducing or-non-oxidizing oforifices i2 providedin the pipe H. 7 During this 20 'atmospherewithin the still, thereby preventing "circulation of themixture of oil and clay, the mix- "oxidation" of the oil and reducing'the amount of h is preheated as i pa s through t e p p "clay required to bleach the oil to a given color, and upon being discharged under pressure below said gases being first subjectedto a treatment the level of the liquid within the container 2,-a

;whereby.the o is removed th ref om d turbulence of themixture'is created within said 25 th n injected into the mixture of oil and lay c ntai ves 3, l4 d I5 a ep v d i within-the still in a manner to increase the agitacontrol the flow o liquid through the c ul t tion thereon I 7 p means. i I V j Another object of the invention is to rovide 2. During h p at f h st l a r du o means whereby the gases and products of vaporihon-oxidizing atm p e e i m i t d t e 30 'zation generated within the' still may be disby utilizin 'waste flu g s s t at a generated charged therefrom and the 'condensable portions yffi Still- VT s d a p 5' i ct d' 50 thereof liquefied-and discarded while the gaseous stack 5 i a manner to o c te w h or non-condensable portions thereof are united flue 5 thereof. The p communicates With 3 with t e flue gases and deoxidize din unison thereac o of w -kn wn m ,byvmcens '35 with and a'gain injected into the mixture of oil or which the waste flue gases are withdrawn from "and clay, or by-passed from the oxidizing; agent fiue 5 compressed and forced through a p and carried directly back to the stilL-if so de- I 8 i to a container I9 v e is a sired. r oxidizing agent such, for examplaraspyrogallio 40 still another object of the'invention is to reduce d o t d therein: This id i g agent 40 t m hazard which is usually r t i th is so confined within the container Is that all type of apparatus. 9 i of the gases passing through said container will The invention consists in an appara us nd beiconducted into closeassociationtherewith in process for re-refining waste lubricating oil as 'Such a manner a the O id g agent Swill set forth in the following specification and parb o b th i y from h gases 45 ticularly aspointed'out in the claims thereof. 'whi'ch remain, which now' contain o poz land The figure of-the drawing represents an ap- =N2 are conducted throug a p p 0 d rectly into paratus embodying my invention and by means of the container 2 where they a e di h r which the process 'of-this invention carried thro h a-p ura y' f r fi s int th mix- 60 out. E i V I ture of ciland. clay below the surface; of said In'the drawing, [represents a still embodying mixture. These gases are discharged under therein a horizontally disposed cylindrical conpressure into themixture of oil and clayand the V tainer' 2 for a mixture of waste lubricating oil I turbulence of said mixture istherefore increased; and clay 3 "mixed in suitable proportions and in A valve 22 is provided for thepipe connection a manner well-known to those skilled in the art. iii-and valves '23 and are provided for the pipe) connections "I8 and 20 respectively. "A by-pass valve provides a means of intercommunication between the pipe I8 and the pipe 20 and is provided with a valve 26. By'opening the valve 25 and closing the valves 23 and 24 the container I9 containing the deoxidizing agent may be eliminated from the system for reasons hereinafter to be more fully disclosed. 7 1

During the operation of the still gases and vapors are generated therein. The vapors are formed because of the presence of water and gasoline contained withirrthe waste lubricating oil. It is necessary, therefore, to eliminate these vapors and for this purpose a pipe 21 leads" from the top of the container 2 to a condenser 28 pro.- vided with a coil 29 which-is exposed to a suitable cooling fluid, preferably water, which is allowed to flow through the condensen said water entering the condenser through an inlet pipe 30 and beingvdischarged therefrom througha discharge pipe 3|. The coil 29 is connected by means of a pipe 32 to a container 33 inwhichthe products of condensation are collected and may be withdrawn therefrom through a pipe 34 having a valve '35 provided therein. The gases which enter "the container 33 are withdrawn therefrom through a pipe 36 which communicates with the pipe connection I6 leading to. the compressor IT. A valve 37 is provided for the pipe connection 36. After themixture of waste lubricating oil and clay has been treated within the still for the necessary period, the mixture is withdrawn from the container 2 and filtered by a mechanism as fol1ows:-Connected to thepipe II is a'pipe 38 which communicates with an agitator 39. A valve 40 is providedfor the pipe 38. As the "mixture of oil and clay passes through the agita- Jtor 39a turbulence of said mixtureis created therein by means of suitable paddle blades 4I provided upon a'shaft 42 rotated in any suitable manner by mechanism not shown but well known to those skilled in the art. A pipe 43 connects the a'gitator 39 with-a cooler 44 provided with .a coil '45 therein through which the mixture may flow, a1l the time being exposed to acooling agent,

preferably water, which entersthe cooler through an inlet pipe 46 and is discharged therefrom through a pipe 41. The cooler 44 is connected by means of a pipe 48 witha filter 49 of wellknown construction in which isa suitable filtering medium"which is adapted to. separate from :the oilthe clay and all other foreign solid matter contained therein. The re -refined oil is withdrawn from the bottom of the filter through a pipe 50having a valve 5| provided therein.

The general operation of the apparatushereinbefore specifically described and by meansof which the process-of this invention is carried out is as follows :-Waste lubricating oil; containing various'types of foreign matter, together with a certain amount of clay utilized as a bleaching agent andwell known in oil refining processes, is fed intoJthelcontainer 2 and subjected toheat provided'by the furnace 4, said heat contacting 65 directly with the under side of the container. During'this'he'ating process the liquid within the container withdrawn therefrom by means of the pump I3 and forcedthroughthe pipes 9 which are located in the upper part of the fur.-

nace 14.. As the. liquid circulates through these f pipes it is preheatedand finally forced back into 'the conta'iner 2 below theQlevel ofuthe'liquid therein. in a manner to create a turbulence of said liquid within the container. The liquid is subjected to heatuntil the temperature thereof ranges from 550F. to 650 F. During this heattreating operation waste flue gases generated within the furnace and conducted outwardly therefrom through the flue 6 are utilized as a means for maintaining a reducing or non-oxidizing atmosphere within the container 2 of the still. A portion of these waste flue gases which may contain 002, O2 and N2 are withdrawn from the fine '5 and compressed by means of the compressor I1 and discharged into contact with the deoxidizing agent which is located within the container I9, which will absorb the free 02. The COzand N2 which remain are then forced into the container 2 and discharged therein below the level of 'the' mixtureii in a manner to still further increase 'theturbulence of said mixture. During this operation certain gases and vapors are created in the container 2 and are discharged therefrom through the pipe ZI'into the condenser 23 where the products of vaporization are liquefied and finally discharged into the container 33 together warms gases which remain unliquefied. The liquid can be drawn off at any time by manipulating the valve 35. The gases are withdrawn from the container 33 by means of the compressor H and are compressed and deox'idized of any further free O2 that may .be contained therein in unison with the flue gases by means of the deoxidizing agent contained within the container 1 9,;being finally discharged into a container 2 of the still as previously mentioned. a

After the'still has been in operation a predetermined length of tirneand tests disclose the fact that all of the free 02 which is in circulation has been removed, the valve 22 is-operated to cut out entirely the flue I5, thereby preventing any more waste. fluef'gases from being placed in circulation; With all of the free 02 removed it is no long'ernecessary to utilize the deoxidizing medium L .in the system and this is therefore. cut out by closing the valves Band. The valve '26 is then opened and the gases and vaporsare thereafter withdrawn from the top of the container 2 andiafter being conducted through the condenser @ha'sbeen in operation for a predetermined period 5 ,at ,a" temperature Whichmayrange between 550 .F. and 650 F. the valve I5 is closed and the valve '40'ope'nedandthe liquid in a partly refined state is withdrawn from the container 2 of the still andforced by means of the pump lflsuccessively through the agitator 39, cooler 44 and filter 49 andtheliguid is successively agitated, cooled to la certain extent,;and filtered. During this filtering operation the clay and foreign solid matter that still may be contained within the oil is removed from said-oil. and the resulting re-refined oil may be withdrawn from the filter by manipulating the valve 5I.

I By closing the valves I3 and I5 the preheating operation may be cutout of the system at any time and if any leak appears in-the pipes 9 the valve I3 may be actuatedto prevent'the oil-from entering these pipes and" subsequently leaking into the furnace. This construction reduces'certainfire hazards that would otherwise exist; :By

reducing the amount of free 02 present the fire ,hazard is also. reduced. By utilizing waste flue gases and removing the freeOz therefrom the expense of'operating the, still is greatly reduced. By increasing both the heating efliciencyand means to withdraw gases and vapors from said oil velocity as said oil passes through the preheating tubes, a reduction in the oil film thickness is obtained. The increased velocity of the oil through the tubes 9 reduces the possibility of the oil cracking, to a minimum.

While I have illustrated and described the waste flue gases utilized in the process of this invention as being obtained from the flue leading from the furnace to the still, it is evident that waste gases may be obtained from the stack or flue of any other furnaces that may be located upon the premises adjacent to the'still without departing" from the spirit of this invention.

I claim:

1. An apparatus for re-refining waste lubricating oil comprising, in combination, a still adapted to contain a mixture of waste oil and clay, means to withdraw gases and vapors from said still and waste gases from the flue thereof, means to condense said vapors, means to deoxidize all of said gases, means to inject said deoxidized gases into the still, means to cut out the flue gases, means to cut out the deoxidizing means, means to return the gases withdrawn from the still back into said still to maintain a non-oxidizing atmosphere therein, and means to filter said mixture to remove the clay and other foreign matter therefrom.

2. An apparatus for re-refining waste lubricating oil comprising, in combination, a still adapted to contain a mixture of waste oil and clay, means to withdraw said mixture from said'still, preheat the mixture and again discharge the mixture into the still below the level of the liquid therein,

still and waste gases from the flue thereof, means to condense said vapors, means to deoxidize all of said gases, means to' inject said deoxidized gasesinto the still, means to cut out the flue gases, means to cut out the deoxidizing means, means to return the gases withdrawn from the still back into said still to maintain a non-oxidizing atmosphere therein, and means to filter said mixture to remove the clay and other foreign matter therefrom.

3. The process of re-refining waste lubricating oil which consists in applying heat to a mixture of waste oil and clay, maintaining a non-oxidizing atmosphere within said mixture by passing hot waste flue gases through pyrogallic'acidand injecting the so-treated gases into the mixture, and finally filtering the mixture to remove the clay and other foreign particles therefrom.

'4. The process of re-refining waste lubricating oil which consists in applying heat to a mixture of waste oil and clay, agitating said mixture by withdrawing the same from the mass thereof, preheating it, and thenreturning it under pressure into the mass below the level thereof, maintaining a non-oxidizing atmosphere within the mixture by passing hot waste flue gases through pyrogallic acid and inj cting the so-treated gases,

while hot, into the mixture below the level thereof,

thereby increasing the turbulence of said mixture,

and finally filtering the mixture by removing the clay and other foreign matter therefrom.

GEORGE RICHARD DUFFY.

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