US2714574A

US2714574A - Degreasing and cleaning apparatus

Info

Publication number: US2714574A
Application number: US372269A
Authority: US
Inventors: Thomas J Kearney
Original assignee: Detrex Corp
Current assignee: Detrex Corp
Priority date: 1953-08-04
Filing date: 1953-08-04
Publication date: 1955-08-02
Anticipated expiration: 1972-08-02

Description

Aug. 2, 1955 T. .1. KEARNEY DEGREASING AND CLEANING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 4, 1953 INVENTORS (IS Jfr'efl/zez 4 4 A TTORNEYS.

CNQCN g- 2, 1955 T. J. KEARNEY DEGREASING AND CLEANING APPARATUS 6 Sheets-Sheet 2 Filed Aug. 4, 1955 INVENTOR. 6'0 @62 BY Z ATTORNEYS.

Aug. 2, 1955 T. J. KEARNEY DEGREASING AND CLEANING APPARATUS 3 Sheets-Sheet 3 Filed Aug. 4, 1955 INVENTOR.-

A TTORNEYS.

WK T United States Patent DEGREASTNG AND CLEANING APPARATUS Thomas J. Kearney, Detroit, Mich, assignor to Detrex Corporation, Detroit, Mich a corporation of Michigan Application August 4, 1953, Serial No. 372,269

9 Claims. (Cl. 202-169) The present application is a continuation of a previous application, Serial No. 288,905, now abandoned, filed by me on May 20, 1952, for the same subject matter.

This invention relates to degreasing and cleaning apparatus intended more particularly for treatment of loose materials, i. e. metallic chips or very small machine parts and the like with chlorinated hydrocarbon solvents such as trichlorethylene or perchlorethylene.

The chief aim of my invention is to provide a simple and reliable apparatus in which degreasing and cleaning of loose materials or articles of the kind referred to can be carried out quickly in a continuous and efficient manner by immersion in hot solvent, with incidental continuous controlled cycling of the solvent between liquid and vapor phases, and with minimum attendant loss of the solvent employed in the treatment.

Other objects and advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. 1 is a view in top plan of a degreasing and cleaning apparatus conveniently embodying my invention.

Fig. 2 shows the apparatus in side elevation with portions broken out and in longitudinal section.

Figs. 3 and 4 are transverse sections taken as indicated respectively by the angled arrows TIL-III and IV-IV in Figs. 1 and 2.

As herein exemplified, my improved degreasing and cleaning apparatus comprises an enclosure which is elongate quadrangular in configuration and which has straight continuous side and

end walls

11, 12 and 13, 14 respectively, a bottom 15, and a partial roof 16, all fashioned in practice, from heavy gauge corrosion-resistant sheet metal such as No. 10 gauge stainless steel clad plate. A transverse vertical dam partition 17 extending partway up within the enclosure 10, serves to set apart a relatively large solvent evaporating compartment 18, and an immersion tank 19 through which the material to be treated is passed as presently explained. During operation of the apparatus, liquid solvent constantly flows from the tank 19 over the top of dam partition 17 into the evaporating compartment 18, the quantity of solvent normally contained in said compartment being approximately to the level indicated at L in Fig. 2. Disposed within the bottom of compartment 18 is a horizontally-arranged steam coil 20 for heating the solvent, to which coil steam is conducted through a pipe 21 under control of a flow regulating valve 22 controlled by a thermostat, not shown, immersed in the solvent. The opening 23 at the top of the enclosure 10 over compartment 18 is normally closed by retractable hinged covers 24, to prevent escape of fumes rising from the hot solvent in said chmaber. Surrounding the enclosure adjacent the top is a jacket 25 through which cold water or other suitable coolant is constantly passed to establish a low temperature chilling zone within the housing, with consequent maintenance of a top limit level approximately at L for the solvent vapors. The vapor condensate forming on the cooled portions of the walls of the enclosure at the chilling zone, collects in ii atented Aug. 2, 1%55 an internal peripheral gutter 27 and is conducted from the latter by way of a pipe 28, to a water separator 29 l at the exterior. After removal of the water, the reclaimed solvent is ordinarily returned to tank 19 by way of pipes 51 and 3t), and by a guide trunk 42 thereinafter more particularly described. The hand valve Si. in pipe 30 is normally kept open.

The material to be treated in the apparatus is fed from a hopper 35 onto a vibrated metering device 36 which discharges through an opening 3'7 in the roof portion 16 of the enclosure 10. The material is then directed by communicating vertical duct 38, defined in part by partition 39, into the solvent bath in the immersion tank 19. As the material sinks in tank 19, it is picked up by an endless conveyer 4% herein shown by way of example, as being of the sprocket chain type with attached flights 41 at intervals of its length. Conveyer 40 is constrained to travel within a tubular guide trunk 42 formed into a quadrangular loop which is disposed in a vertical longitudinally-extending plane and which is located partly within the enclosure 10 and partly exteriorly thereof. As shown, the portion of trunk 42 within the enclosure 1%) slopes upwardly and rearwardly, its upper and lower portions being horizontal and parallel and the external upright portion being at a true vertical. Interposed between the upper horizontal portion of the trunk 42 and the vertical external portion of the trunk 42 is a casing 42a containing the sprocket wheel 43 about which the chain of conveyer 44 is trained. Sprocket wheel 43 is adapted to be driven at a proper constant speed by suitable means not illustrated. As shown in Fig. 2, the lower horizontal portion of trunk 42 communicates with the immersion tank 19 through aligned openings 44 and 45 respectively in the end wall 14 of the enclosure 10 and in the dam partition 17. That portion of trunk 42 located in tank 19 is open at the top with the bottom half forming the lowermost portion of said tank 19. The sloping sides 47 are attached to the bottom portion of tube 42 and consequently the material is fed into the tube 42 where it is carried along by the conveyer flights 41.

At a point above the vapor level in compartment 18, see Fig. 2, the sloped portion of trunk 42 is provided in its top side with an opening 48 to permit escape of solvent vapors from the material carried up by conveyer 4t Surrounding the trunk 42 immediately below the opening 48 is a chilling element 49 by which solvent vapors emanating from the hot material are condensed for drainage back into the bottom of the trunk before reaching the opening 48. Immediately above the opening 481 is a surrounding steam jacket 54 for vaporizing most of any solvent still remaining on the material. In this connection, it is to be noted that the pipe 30 hereinbefore referred to, conducts some of the clean solvent from water separator 29 into conveyer trunk 42 at a point somewhat above the solvent level in said trunk for discharge upon the material before it arrives at the opening 43. The balance of the distillate is returned directly to immersion tank 19 by way of pipe 51.

As further shown in Fig. 2, the horizontal upper portion of the trunk 42 extends through the top of a closed aerating tower 55 positioned beyond the right hand end of the enclosure 10, into which tower the now degreased material is discharged through an opening 56 in the bottom of said trunk portion. Like the enclosure 10, the aerating tower 55 is constructed from suitably stout corrosion-resistant plate metal. In dropping within tower 55, the fall of the material is broken by a series of opposed sloping bafiles 57 which may be of fiber or the like. At the same time, drying air impelled by an electric motor-driven blower 58 is blown upwardly through the devious course defined by the baffles 57 within the tower. As shown, the blower 58 is interposed in an external duct 59 connecting an induction port 60 near the bottom of the tower with an eduction port 61 near the top of the tower. Heaters conventionally represented at 62 and located within the induction end of duct 59, serve to heat the air before it enters the tower. Also interposed in duct 59 is a trap 65 with a transverse dust and dirt screening diaphragm 66 therein, and with a condenser pipe coil 67 below said diaphragm through which latter fluent coolant is constantly circulated. Any residual solvent evaporated from the material by the warm air circulated through tower 55 is condensed continually to liquid form by the action of coil 67, and the condensate is conducted from the bottom of the trap 65, through a pipe 68, to a water separator 69. After traversing the separator 69, the clean recovered solvent is finally conducted, through a pipe 70 (Figs. 1 and 4), back to tank 19 within the enclosure 10.

By reference to Fig. 4, it will be seen that the bottom 71 of aerating tower 55 is sloped for gravitation of the now degreased material to another endless flight conveyer 72 which is constrained to travel in a separate vertically and longitudinally-arranged loop trunk 73. As shown, conveyer 72 is trained about a sprocket wheel 75 within a protective casing 76 interposed in trunk 73. It is to be understood that, in order to preclude clogging of the apparatus, conveyer 72 is progressed at a speed somewhat in excess of the speed of conveyer 40, by suitable drive means (not shown) connected to sprocket wheel 75. By conveyer 72, the cleaned material is elevated to an inclined discharge spout 77 at the top of the trunk 73. The electric motor-driven blower indicated at 78, draws air upward through discharge spout 77 counter to the movement of the material in the latter for deodorizing purposes.

The flight conveyers herein illustrated are to be considered as typical of other kinds of conveyers which may be substituted without sacrifice of any of the advantages of my invention.

Further embodied in the apparatus is a solvent storage reservoir 80 which, as shown in Figs. 1 and 2, is positioned adjacent the left hand end of the enclosure 10, and which, like said enclosure and the aerating tower 55, is constructed from corrosion-resistant plate metal. When removal of accumulated sludge and dirt from the enclosure is necessary or desirable after protracted periods of operation of the apparatus, all of the solvent is temporarily transferred to storage reservoir 80. For this purpose I have provided, as shown in Fig. 2, a motor-driven reversible pump 81. Connected to one side of pump 81 is a pipe 82 having branches 83 and 84 which terminate respectively at the bottom of compartment 18 and at the bottom of immersion tank 19. The

valves

85 and 86 respectively in the branches 83 and 84 are normally kept closed. Leading from the other side of pump 81 to storage reservoir 80 is a pipe 87. As further shown, there is a pipe connection 89 between the water separator 29 and the top of storage reservoir 80 having therein a hand valve 90 which is also normally kept closed.

Operation The soiled material continually fed from the hopper and metered by the vibrating element 36, drops into the immersion tank 19 where it is subjected to the degreasing and cleaning action of the solvent. As the conveyer traverses tank 19 in the direction indicated by the arrows in Fig. 2, the material is carried up into the inclined fore part of trunk 4-2 wherein the solvent stands at a level even with that in said tank. As the material emerges from the solvent in trunk 42, it is flushed with clean solvent delivered through pipe 30 from the water separator 29. Further up in the fore part of trunk 42, the material is chilled under the influence of the condenser element 49, for release therefrom of most of the solvent in liquid form, while some of the vapor escapes through the opening 48. After passing the opening 48, the material is reheated by the element 50 enroute to aerating tower. In tower 55, the counter-flowing heated air, circulated by blower 58, drives off any remaining traces of solvent from the material as vapor which is condensed by coil 67, the c011- densate being freed of water content in passing through the separator 69, and being finally returned to tank 19 by Way of pipe 70. The dried material is continually removed from the bottom of tower 55 and elevated in trunk 73 to the discharge spout 77 by conveyer 72, with incidental deodorization thereof by contact with the stream of air sucked into said spout by the action of fan 78.

From the foregoing it will be seen that the solvent cycle is as follows: The vapors, created by heating of the solvent in compartment 18 and condensed at the chill zone maintained by jacket 25, are collected in trough 27, and the condensate is conducted, through pipe 28, to water separator 29. After being freed of water, part of the recovered solvent is carried to conveyer trunk 42 by pipe 30, and the remaining part conducted directly back to tank 19 by way of pipe 51. In this way constant circulation is maintained, with continual flow of solvent from tank 19 over the dam wall 17 into the evaporating compartment 18.

When the housing is to be emptied of the solvent, valve 31 is closed, and valve 90 is opened to permit drainage from the separator 29 into storage reservoir 80. Valves and 86 are also opened and the pump 81 is started in the proper direction to draw the solvent from the compartment 18 and also from the tank 19 through the piping 82, 83, 84, and to discharge the same into the storage reservoir by way of pipe 87. After the solvent is completely withdrawn, the pump 81 stopped and the accumulated sludge and dirt is removed from compartment 18 and from the tank 19, access being had to said compartment upon removal of a panel 91 (which carries the heating coil 20) from over an opening in the front wall 11 of enclosure 10, and upon removal of a similar panel over wall opening (not shown) adjacent said tank. After the sludge and dirt has been disposed of, the

valves

85, 86 are re-opened and the pump 81 operated, this time in reverse, until the solvent has all been returned to compartment 18 and to tank 19, whereupon valve is closed and valve 31 re-opened for resumption of the degreasing and cleaning process as before.

Having thus described my invention, 1 claim:

1. In degreasing apparatus for cleaning loose material such as chips or small articles by treatment with hot liquid solvent such as trichlorethylcne or the like, a walled enclosure having an immersion tank therein for the hot solvent; a passage through which the contaminated material is introduced from above at the exterior of the enclosure to drop into the immersion tank; an aerating tower adjacent the enclosure; a trunk extending up through the enclosure to the exterior and connecting into the top of the aerating tower'said trunk having conveyer means therein for lifting the material from the bottom of the immersion tank for delivery to and gravity release to drop within the aerating tower; and a second separate trunk extending up from the bottom of the drying tower and having conveyer means therein for lifting the dried cleansed material to a higher level for discharge from the apparatus.

2. Degreasing apparatus, according to claim 1, further including means for condensing solvent vapors in the upper part of the enclosure and conducting the condensate back into the immersion tank; an evaporting compartment adjacent the immersion tank within the enclosure for receiving the overflow from the immersion tank and having heating means therein for boiling the solvent.

3. Degreasing apparatus, according to claim 1, further including a jacket for circulation of coolant surrounding the upper portion of the enclosure for maintenance of a vapor limit level within the enclosure; a gutter for receiving the vapor condensate collecting on the Walls of the enclosure; and piping for conducting the condensate from the gutter into the first mentioned trunk at a level above the immersion tank to flow back into the later by way of the trunk counter to the direction of travel of the material in said trunk.

4. Degreasing apparatus according to claim 1, wherein the first mentioned trunk has an opening therein for escape of solvent vapor into the upper part of the enclosure; and cooling and heating means respectively surrounding the trunk immediately below and above the vapor escape opening therein.

5. Degreasing apparatus, according to claim 1, further including means for condensing solvent vapors in the upper part of the enclosure and conducting the condensate back into the immersion tank; an evaporating compartment adjacent the immersion tank within the enclosure for receiving the overflow from the tank and having heating means therein for boiling the solvent; a solvent storage reservoir exteriorly of the enclosure; piping extending from the reservoir to the immersion tank and the evaporating compartment; a reversible pump interposed in said piping; and reversible drive means for the pump whereby replenishing solvent can be transferred from time to time from the reservoir to the immersion tank and to the evaporating compartment, or from the immersion tank and the evaporating compartment to the reservoir when sludge removal becomes necessary.

6. Degreasing apparatus, according to claim 1, further including means for circulating heated air upward through the aerating tower.

7. Degreasing apparatus according to claim 1, further including means for circulating heated air upward through the aerating tower; and battles Within the aerating tower for breaking the fall of the material, and for constraining the air to a sinuous course in its upward flow through the tower.

8. Degreasing apparatus according to claim 1, further including means for drawing air from the delivery end of the second mentioned trunk in a direction of travel of the cleansed material for deodorizing purposes.

9. Degreasing apparatus, according to claim 1, further including means for circulating heated air in the aerating tower, said means comprising an exterior return conduit; a blower interposed in said pipe with a heating means and a solvent condenser; and piping for conducting the recovered solvent from the condenser back to the immersion tank.

References t'jited in the file of this patent UNlTED STATES PATENTS 351,929 Lillie Nov. 2, 1886 913,751 Mills Mar. 2, 1909 1,694,361 Sterling Dec. 4, 1928 1,862,945 Schlotterhose June 14, 1932 2,088,190 Du Pont July 27, 1937 2,089,102 Savage Aug. 3, 1937 2,101,840 Dinley Dec. 14, 1937 2,104,103 Ruthven Jan. 4, 1938 2,104,992 Hollerer Jan. 11, 1938 2,137,479 Dinley Nov. 22, 1938 2,162,656 Warrington June 13, 1939 2,187,208 McDonald Jan. 16, 1940 2,201,729 Hood May 21, 1940 2,270,742 Somes Jan. 20, 1942 2,273,557 Bonotto Feb. 17, 1942. 2,280,811 Edhofer et a1 Apr. 28, 1942 2,560,767 Huff July 17, 1951

Claims

1. IN DEGREASING APPARATUS FOR CLEANING LOOSE MATERIAL SUCH AS CHIPS OR SMALL ARTICLES BY TREATMENT WITH HOT LIQUID SOLVENT SUCH AS TRICHLORETHYLENE OR THE LIKE, A WALLED ENCLOSURE HAVING AN IMMERSION TANK THEREIN FOR THE HOT SOLVENT; A PASSAGE THROUGH WHICH THE CONTAMINATED MATERIAL IS INTRODUCED FROM ABOVE AT THE EXTERIOR OF THE ENCLOSURE TO DROP INTO THE IMMERSION TANK; AN AERATING TOWER ADJACENT THE ENCLOSURE; A TRUNK EXTENDING UP THROUGH THE ENCLOSURE TO THE EXTERIOR AND CONNECTING INTO THE TOP OF THE AERATING TOWER SAID TRUNK HAVING CONVEYER MEANS THEREIN FOR LIFTING THE MATERIAL FROM THE BOTTOM OF THE IMMERSION TANK FOR DELIVERY TO AND GRAVITY RELEASE TO DROP WITHIN THE AERATING TOWER; AND A SECOND SEPARATE TRUNK EXTENDING UP FROM THE BOTTOM OF THE DRYING TOWER AND HAVING CONVEYER MEANS THEREIN FOR LIFTING THE DRIED CLEANSED MATERIAL TO A HIGHER LEVEL FOR DISCHARGE FROM THE APPARATUS.