US2842143A

US2842143A - Apparatus for ultrasonic cleaning of parts with a solvent

Info

Publication number: US2842143A
Application number: US517022A
Authority: US
Inventors: Thomas J Kearney
Original assignee: Detrex Corp
Current assignee: Detrex Corp
Priority date: 1955-06-21
Filing date: 1955-06-21
Publication date: 1958-07-08
Anticipated expiration: 1975-07-08

Description

.July 8, 1958V 1'. J. KEARNEY APPARATUS FOR ULTRASONIC CLEANING OF PARTS WITH A SOLVENT Filed June 21. 1955 3 Sheets-Sheet 1 I INVENroR. Thal/10s I Kean/zeg BY Puf at 62M ATTORNEYS.

July 3, 1958 TJ. KEARNEY 2,842,143

APPARATUS FOR ULTRASONICv CLEANING OF' PARTS WITH A SOLVENT med June 21, 1955 s sheets-sheet 2 f' A 11 ij July 8, 1958 T. J. KEARNEY 2,842,143

APPARATUS yFOR ULTRASONIC CLEANING OF PARTS WITH A SOLVENT Filed June 21, 1955 3 sheets-sheet s FIG. 5;

62 I l i l l 5] gg --]Z INVENTOR: T/w/wsCZ/ieal'lley,

BY MIM A TTORNE YS.

United States atent Oce 2,842,143 Patented July 8, 1958 APPARATUS FR ULTRASNIC CLEANING F PARTS WITH A SLVENT Thomas .1. Kearney, Detroit, Mich., assigner to Detrex Chemicai Industries, Inc., a corporation of Michigan Appaeauon am@ 2i, 195s, serial No. 517,022

4 claims. (ci. 134-56) This invention relates to apparatus for treating a work object. More specitically, it is concerned with hand operated apparatus for cleaning and degreasing intricately formed metal parts, as for example, cutters for electric razors, hypoderrnic needles and deep drilled parts, through the combined application of heated chlorinated hydrocarbon solvents and ultrasonic energy. Reference is hereby made to my co-pending application Serial No. 461,871, tiled October 12, 1954, now Patent No. 2,771,086, dated Nov. 20, 1956, of which this application is a continuation-in-part.

it is an object of the present invention to provide a new and improved hand operated mechanism for cleaning and degreasing a work object with ultrasonic energy in a liquid.

lt has been found that the impedance of barium titanate transducers immersed directly in the liquid of an ultrasonic well varied as the temperature of the liquid changed. In order to obtain maximum sonics activity and maximum etiiciency it is necessary that the impedance of the generator be matched to the impedance of the transducers. inasmuch as it is impractical to constantly adjust the generators to compensate for the change in impedance of the transducers caused by the change in the temperature of the liquid it has been found necessary not only to circulate and cool the liquid of the ultrasonic well but also to supply a temperature control for this well. This is accomplished as hereinafter more fully described.

Other objects and advantages of the invention, including the simplicity and economy of the same, will be understood from the detailed description to follow, throughout which reference is rnade to the accompanying'drawlugs.

Fig. 1 represents a view in front elevation of a clean ing apparatus constructed in accordance with the invention; v

Fig. 2 represents an end view of the apparatus taken as indicated by the lines and arrows lII--l'I of Fig. l;

Fig. 3 represents a View of the opposite end of the apparatus as indicated by the lines and arrows III-III appearing in Fig. 1;

Fig. 4 represents a view in rear elevation of the apparatus of Fig. 1; and Y Fig. 5 represents a view in front elevation of an alternate form of cleaning apparatus constructed in accordance with the invention.

Turning now to the drawings and the specic forms of the invention selected for illustration therein, the cleaning apparatus comprises a housing 11, which may be of sheet metal, in the lower portion of which are serially arranged a boiling well 12 and an ultrasonic well 13 separated by an overflow dam 14.y A liquid, preferably a chlorinated hydrocarbon liquid such as trichlorethylene, is normally maintained at a level L1 in boiling well 12 and is constantly boiled by the action of a submerged heating coil 15, the ends of which are supported in a removable cleanout door 16 at 17 and 18. Arranged over the heating coil 15 is a work restV 19 on which the work object to be cleaned Vis .placed during the boiling step of the process.

The ultrasonic well 13 is kept liilled with liquid to ya level indicated at L2, and disposed within saidwell near the bottom are ultrasonic vibration means 20 which may be of the form disclosed in the co-pending patent application of Thomas J. Kearney, Serial No. 435,888, filed June 10, 1954, now Patent No. 2,802,476, dated Aug. 13, 1957. Arranged above the ultrasonic vibration means 20 is a workrest 21 on which the work object is placed for ultrasonic cleaning.

The vapors generated in boiling well 12 rise within housing 11 and are condensed by a cooling jacket 22 which completely surrounds housing 11 at a level above the surface of the liquid but well below the top of housing 11. A coolant (which may ybe water) is circulated v within the jacket 22 which condenses the rising vapors and prevents the escape of said vapors through the open top of housing 11. The open top of housing l11 lpro- Vides an access through which the work object is passed to the

wells

12 and 13 for cleaning. The condensed vapors are collected in a trough 23 which extends entirely around the interior of the housing 11 below the cooling jacket 22. From trough 23, the condensed vapors are conducted through a conduit 24 into a condensate receiver 25 for storage and cooling. Upon reaching a predetermined height, excess condensate overows through a conduit 26 into ultrasonic well .13. This excess condensate introduced into the ultrasonic well 13 causes the liquid in Well 13 to overflow dam 14 into boiling well 12 where the vapors are formed and given ofi to be subsequently condensed, cooled and returned to the boiling well, thus maintaining a continuous cycle.

The condensate that does not pass through conduit 26 is drawn from condensate receiver 25 through a conduit 27 and a valve 28 by a centrifugal pump 29 and thence conducted through a conduit 30 into the housing 11 at 31, and through exible conduit 32 to spray lance 33 having a nozzle 34 and a handle 35. This spray lance 33 is used to liush the condensed clean distilled liquid over the work object to remove any loosely athxed dirt particles remaining thereon. The flexible conduit 32 permits moving the spray lance 33 to any desired position to accomplish the said ushing. i v

For the purpose of keeping the liquid within ultrasonic well 13 clean, there is provided a iilter system which comprises a conduit 36 leading from thebottom of well 13 through the housing 11, a valve v37, a conduit 38, a pump 39, belt driven by a motor 40, a conduit 41, a filter 42, a conduit 43,a valve 44, and a conduit 45 which returns to the bottom of well 13 through the housing 11. The liquid in ultrasonic well 13'is constantly circulated through and cleaned by this filter system during the operation of the apparatus.

Two curved barium titanate transducers 46 and 47 are mounted in the bottom of ultrasonic well 13 in a manner such as shown in co-pending application Serial No. 435,888, tiled on June 10, 1954. The temperature of the liquid in well 13 is maintained below that of the liquid in well 12 by diverting the hot condensate through the condensate receiver 25 and by circulating the liquid of well 13 through the ltering system. There is a further diversion 'and cooling of solvent through the spray system. Transducers 46, 47 'beam ultransonic energy through the liquid contained in well 13. Power is supplied to transducers 46 and 47 by an electric oscillator Aunit 48 (Fig. 2) through electrical conductors' 49 which enter housing 11 through fitting 50 and pass downwardly into ultrasonic well 13to transducers 46, 47. j

Fig. 4 illustrates the drain conduit 51 and its associated

valves

52 and 53. Drain conduit 51 leads from the bottom of Wells 13 and 12 to a liquid solvent storage tank (not shown) and permits the draining of said wells and the storage of said liquid when the apparatus is not muse.

Fig. 3 illustrates the apparatus and conduits associated with submerged heating coil 15. The steam passes through a conduit 55, a steam pressure reducer 56, a hydra-motor valve 57, a pop-oft' valve 58, a gauge 59 and a conduit 60 to

removable cleanout door

16 and 18.

A lid 61 is provided to cover the open top of housing 11 when the apparatus is not in use. Extending downwardly from lid 61 is a spray lance support 62 which supports spray lance 33 when the apparatus is not being operated.

Fig. illustrates an alternate form of the cleaning apparatus constructed in accordance with the invention. For the purpose of maintaining the impedance of the barium titanate transducers 46 and 47 at a constant value and of keeping clean the liquid `solvent within ultrasonic well 13, there is provided a combination filter and temperature control system which comprises conduit 36 leading from the bottom of well 13 through housing 11, valve 37, conduit 38, pump 39, conduit 41, a pressure gauge 71 inserted in conduit 41, filter 42, conduit 43, an after-cooler 72 inserted in conduit 43, valve 44, and conduit 45 which returns to the bottom of well 13 through the housing 11. Pressure gauge '/'1 is positioned at the highest point in filter and temperature control system and gives a reading of the pressure in the system produced `by pump 39.

The after-cooler 72 is a heat exchanger and includes a cylindrical enclosure 73, an end cap 74, and an end cap 75 having two apertures therein to permit passage of tubes 76 and 77 into the interior of enclosure 73. Tubes 76 and 77 are formed into coil 78 within Ithe enclosure 73 and the coil 78 is heated or cooled to the desired temperature by passing water or steam of the required temperature therethrough. A temperature control valve 81 is inserted in tube 77 and is controlled by sensitive bulb 82 submerged in the conduit 36 where it enters well 13; bulb 82 being connected to control valve 81 by tube 83.

Enclosure 73 is provided with an intake aperture 84 and an output aperture 85. The liquid chlorinated hydrocarbon passes from filter 42 through conduit 43, and then through intake aperture 84 into enclosure 73 where it is brought to the desired temperature by contact with coil 78 and passed out through output aperture 85 to conduit 43, valve 44, and conduit 4S which returns the said liquid to the bottom of well 13 through housing 11.

The alternate form of the cleaning apparatus illustrated by Fig. 5 shows the drain conduit 51 and its associated

valves

52 and 53 mounted on the front of housing 11, one end of conduit 51 connecting to well 12 directly through housing 11 and the other end of conduit 51 connecting to the bottom of well 13 through conduit 36.

A Work object to be cleaned in the hereinbefore described apapratus is first immersed in the boiling liquid of well 12 where it is placed on work rest 19. Then the work object is removed from well 12 and immersed in the liquid of ultrasonic well 13 and is supported therein by work rest 21. While submerged in the liquid of well 13, the work object is subjected to the ultrasonic energy transmitted through the liquid for a period of time sufficient to accomplish the required cleaning. The work object is then removed from the ultrasonic well 13 and a spray of liquid condensate from spray lance 33 is forced over the work object to give it a thorough liquid rinse. The work object is then held in the vapors present between the surface of the liquid land jacket 22 for a final vapor rinse and then dried before removal from the apparatus.

Various other processes of cleaning may be used with the apparatus of this invention. For example, in one such process, the work object is not immersed in the 4 liquid of boiling well 12, but instead is positioned in the hot vapors rising from said well. In another method of cleaning, the work object is `subjected to a spray of liquid condensate prior to being immersed in ultrasonic well 13.

Where the ultimate in cleaning of the condensate and removal of solids therefrom is required, the condensate is passed through a 10 micron or smaller lter (not shown) to eliminate dust picked up by the condensate, preventing said dust from being deposited thereby on the work object.

The transducers 47 can be arranged in any desired position, in parallel or in series, or on a side of the wall in a vertical position for special applications or specific sized or shaped parts.

It is to be understood that the form of the invention herein shown and described is to be taken as a preferred embodiment. Various changes may be made in the shape, size and larrangement of parts. Equivalent elements may be substituted for those described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of other features, all without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

l. Apparatus for treating a work object comprising in combination a housing, an ultrasonic well within the housing containing a liquid chlorinated hydrocarbon bath and having a transducer submerged in said liquid bath whereby the work object is bombarded with waves of ultrasonic energy when said work object is positioned beneath the surface of said liquid bath, means for introducing said liquid chlorinated hydrocarbon into said well at a temperature below boiling, and temperature control means for controlling the temperature of said liquid bath, said temperature control means including heat exchanger means, valve means connected to said heat exchanger means, temperature sensitive means located in said ultrasonic well and connected to said valve means, and conduit means connected between said well and said heater exchanger means and arranged to allow passage of said liquid from said well to said heat exchanger means and return to said well.

2. Apparatus for treating a work object comprising in combination a housing, an ultrasonic well within the housing containing a liquid chlorinated hydrocarbon bath and having a transducer submerged in said liquid bath whereby the work object is bombarded with waves of ultrasonic energy when said work object is positioned beneath the surface of said liquid bath, said transducer bcing energized by an electrical circuit having leads in direct contact with said transducer, means for supporting said leads and said transducer within said wel] in direct contact with said liquid, means for introducing said liquid chlorinated hydrocarbon into said well at a temperature below boiling, temperature control means for alternatively heating or cooling said said liquid chlorinated hydrocarbon to maintain it at a constant temperature, said temperature control means including heat cxchanger means, valve means connected to said heat exchanger means, temperature sensitive means located in said ultrasonic well and connected to said valve means. conduit means connected between said well and said heat exchanger means and arranged to allow passage of said liquid from said well to said heat exchanger means and return to said well, means for alternatively admitting a heating or cooling liquid to said heat exchanger means in response to the change in temperature of the liquid chlorinated hydrocarbon, and movable flushing means adapted to be positioned within said housing to direct a spray of said liquid chlorinated hydrocarbon upon said work object above the surface of said liquid bath to remove loosely clinging dirt attached to said work object.

3. Apparatus for treating a work object comprising in combination a housing, a boiling well within said housing containing a liquid chlorinated hydrocarbon and heating means whereby to boil said liquid in said well, an ultrasonic well within said housing containing a chlorinated hydrocarbon at a temperature below boiling, at least one transducer submerged in the liquid of the ultrasonic well and adapted to impinge the work object with ultrasonic energy, said transducer being energized by an electrical circuit having leads in direct contact with said transducer, said ultrasonic well being separated from said boiling well by a dam permitting overow of said liquid from the ultrasonic well to lthe boiling well, temperature control means whereby to maintain `the liquid of the ultrasonic well at a fixed temperature, a spray lance having a spray nozzle, said spray lance being exibly connected with said housing and the liquid chlorinated hydrocarbon contained therein whereby to ush the work object with said liquid and return said liquid to said wells.

4. Apparatus for ultrasonically degreasing a work object by treatment with a chlorinated hydrocarbon comprising a housing; a boiling well within the housing containing a liquid chlorinated hydrocarbon; heating means positioned within said boiling well and submerged in said liquid whereby to boil said liquid to give ofrr a vapor; a work rest on which the work object is placed in the boiling well, said work rest being submerged in the liquid in said boiling well to subject the work object while placed on the work rest to the action of the liquid while boiling; an ultrasonic well within the housing containing said liquid, the liquid within the ultrasonic well being maintained at a temperature below boiling and at a level above the level of the liquid in said boiling Well; ultrasonic means located in the ultrasonic Well submerged in the liquid; a second work rest on which the work object is placed in the ultrasonic well, said second work rest being submerged in the liquid of said ultrasonic well and being positioned to subject the work object to the action of said ultrasonic means; an overflow dam separating said ultrasonic and boiling wells and adapted to permit liquid to overow from the higher level `of the ultrasonic well to the lower level of the boiling well; a cooling jacket positioned on the housing above the said wells adapted to condense the vapors emitted by the boiling well; a collecting means mounted within the housing beneath said cooling jacket adapted to catch the condensed vapor; condensate receiver means, mounted outside the housing and connecting with said collecting means, wherein the condensed vapors are stored and cooled; a spray lance positioned within the housing above the wells, connecting means including a pump and a flexible conduit between said condensate receiver means and said spray lance; said ultrasonic well having an inclined bottom; a temperature control means for maintaining the liquid in the ultrasonic well at a constant temperature, said temperature control means including a sensitive bulb submerged in the liquid Iin the ultrasonic bath and heat exchanger means positioned outside the housing; a lter means positioned -outside the housing; conduit means including a pump leading from the lower portion of said inclined bottom of the ultrasonic well, through said lilter means and temperature control means and back to said ultrasonic well; wherein the solvent is boiled in the boiling well to emit vapor, condensed by said cooling jacket, collected by said collecting means, cooled and stored by said condensate receiver means, sprayed on the Work object above said ultrasonic well and returned to said well, subjected to ultrasonic action within the ultrasonic well, with drawn from said ultrasonic well, filtered, and returned to said ultrasonic well, and passed over said overflow dam from the ultrasonic well into the boiling well, thus completing the solvent cycle.

References Cited in the le of this patent UNITED STATES PATENTS 1,583,710 Welch May 4, 1926 2,374,535 Gibson Apr. 24, 1945 2,447,840 Boss Aug. 24, 1948 2,464,730 Sutherland Mar. 15, 1949 2,571,581 Kearney Oct. 16, 1951 2,616,820 Bourgeaux Nov. 4, 1952 FOREIGN PATENTS 548,960 Great Britain Oct. 30, 1942

Claims

1. APPARATUS FOR TREATING A WORK OBJECT COMPRISING IN COMBINATION A HOUSING, AN ULTRASONIC WELL WITHIN THE HOUSING CONTAINING A LIQUID CHLORINATED HYDROCARBON BATH AND HAVING A TRANSDUCER SUBMERGED IN SAID LIQUID BATH WHEREBY THE WORK OBJECT IN BOMBARDED WITH WAVES OF ULTRASONIC ENERGY WHEN SAID WORK OBJECT IS POSITIONED BENEATH THE SURFACE OF SAID LIQUID BATH, MEANS FOR INTRODUCING SAID LIQUID CHLORINATED HYDROCARBON INTO SAID WELL AT A TEMPERATURE BELOW BOILING, AND TEMPERATURE CONTROL MEANS FOR CONTROLLING THE TEMPERATURE OF SAID LIQUID BATH, SAID TEMPERATURE CONTROL MEANS INCLUDING HEAT EXCHANGER MEANS, VALVE MEANS CONNECTED TO SAID HEAT EXCHANGER MEANS, TEMPERATURE SENSITIVE MEANS LOCATED IN SAID ULTRASONIC WELL AND CONNECTED TO SAID VALVE MEANS, AND CONDUIT MEANS CONNECTED BETWEEN SAID WELL AND SAID HEATER EXCHANGER MEANS AND ARRANGED TO ALLOW PASSAGE OF SAID LIQUID FROM SAID WELL TO SAID HEAT EXCHANGER MEANS AND RETURN TO SAID WELL.