US 2616820 A
Description (OCR text may contain errors)
INVENTOR. Way/Pm: WA/PCZL foam 5 Boummux ATTOP/VLJ/ M. M. E. BOURGEAUX VIBRATORY CLEANSING OF OBJECTS Flled May 14 1948 Patented Nov. 4, 1952 UNITED STATE-13 r c a FFl-CE VIBBA'EORY CLEANSING OF QBJECTS Application May 14, 1948, Serial No. 27,079 In France May 19, 1947 11 C aims- 1 This invention relates to the cleaning of deposits present on objects, particularly on. metallic objects. These. deposits may have been made intentionally, for example, by the application of protective coatings, or they may have been produced naturally or accidentally, for example as a. consequence, of the pieces remaining in a wet or oxidizing atmosphere, or by reason of the employment of pieces at elevated temperature,
or particularly, they may have been made in the presence of water containing salts, or in the presence of a lubricant. Consequently, the word cleaning as used in this specification is defined as the act of making clean and includes the removal of adhering matter froman object without particular regard to the nature of the matter or the composition of the object. Thus, it includes such things, as the removal of dirt, scale, and rust, or other oxides, and the removal of certain deposits formed during chemical or physico-chemical treatments from the bodies that have been treated. The methods previously used to remove such deposits include washing with water or detergents, scouring with solids .or liquids, and chemical attack, to name some of the more common methods. There is no limit to the size of the cleaning operations that may be undertaken by this invention, which extend from tableware as exemplary of objects of moderate size, to the apparatus and metal pieces of massive size used in heavy industry.
The Wrds"c1eaning liquid refer to any liquid having a tendency to free adherent matter from an object. Such liquids may act as solvents, detergents, emulsifiers, and chemical or physicochemical reagents for the adherent matter, or they may act in other ways according to their own natures when employed in accordance with this invention, and when so employed will beef increased effectiveness.
It has heretofore been proposed to agitate cleaning liquids in contact with the object to be cleaned or to project the cleaning liquid upon such object. This invention is not related to such agitating of the liquid about the object or the object within the liquid, but deals with phenomena of different sort.
It is a general object of the invention to clean objects with increased eificiencyby new methods, or by new methods combined with old methods by which the older methods are improved.
Another object of the invention is to construct apparatus capable of efliciently carrying out the new methods of cleaning,
The objects of the invention are accomplished,
n r y sp a n by s bmitti an PM??? .9 be cleaned to the action of elastic vibrations of hi h requ c t sa vi t qn b i g pr fer.- ably ultra-sonoric. The vibrations may be ap- 5 plied directly to the object or they may be transmitted to it through the medium surrounding it, which is preferably liquid.
e an o c coat wit dGPQr ii t jected to the action of such elastic vibrationsof h h fre ue c e d sits wn e and. a e 9etach d e ou h he ma be s tua d in cavities, such as for example, grooves, inscriptions, or screw thre ads. This cleaning-is genr l b e ra dl It h be??? dem??- strated, on the other hand, that the mate 'al constituting; the object itself remains pra intact, contrary to that which has taken p ce when the removal of the deposit was effectuated by the usual methods, for instance soon brushing, and scraping. All the details. 0 the object, it is to be particularly noted, retai contours perfectly. The volume of cavities present in the piece remain constant. This 'is'of great ed n in ma industr e Pa ch i l he shaping of glass, of plastic or offmet'al ob During the moulding a portion'of the o ect shaped is apt to adhere tqthe mouldjah'dQthe mould itselfv is worn away in removing the, deposits. However, after the treatment with elastic vibrations the object presents walls that are perfectly clean and thatretain' massag ng-1 shape even as to fine lines. one is dealing with a machined object the aspectbf the, walls after cleaning by the new method is comparable to that it possessed immediate1y1aftenthe machining and before itsuse'. L
The frequency of the vibrations employedmay be varied within large limits but isIwi'thin'the sonoricQultra-sonoric range. The .lowestYfrequency is on the order of 500 periods per second and the highest, on the order of 190,000 periods per second. This range extends, therefore, from well within the range of audible musical sounds to an ultrasonoric rate far above cement: the human ear. The order of 500 periods er second gives bad results and the order of lQQO periods per second is considered to be a-practical minimum with metal molds as used in glassmaking a preferred range is 16,000- ,to 50,000 cycles per second.
The inventor has observed that it is practically useful to employ ultra-sonoric vibrations .of medium frequency and even to operate -on. .the border of the audible range. Thus, particularly advantageous results have been attained with a frequency of about 20,000 periods per second; such operations have been carried out with rapidity and to a particularly complete cleansing of the object. Furthermore, at such frequencies the quantity of energy consumed is moderate and the action of the apparatus is silent.
In accordance with one of the characteristics of the invention, the medium that surrounds the piece may be provided with a chemical composition that acts upon the material constituting the deposit. This permits, in the cleaning of the object and the removal of the deposit, the superimposing of the chemical action of the surrounding medium upon the mechanical action of the vibrations.
When the medium surrounding the object to be cleaned is a liquid, and this is the preferred form of the invention, it is possible to choose the liquid so that it will facilitate the action of the vibrations, either for example, by wetting the deposit and thus making its removal easier, or by dissolving the deposit, or by causing it to enter into an emulsion, or by reacting chemically or physico-chemically on the matter constituting the deposit.
It is possible to carry out the invention by any means that will cause elastic vibrations of high frequency to act upon the object directly or through a surrounding medium. Apparatus may be used in accordance with the invention, employing magneto-strictive emitters of sonoric or ultrasonoric vibrations. Another useful form of apparatus includes a piezo-electric emitter of ultrasonoric vibrations. The object to be cleaned may itself be placed in a receptacle or vat containing a liquid which is submitted to vibrations produced by the emitter and this is a preferred form of the invention.
In selecting from the wide fields of industry to which this invention is applicable, one field to be employed as illustrative, the glass industry is chosen because the moulds used in shaping glass objects are particularly subject to the accumulation of deposits and the deposits themselves have heretofore proved hard to remove. The glass moulds are generally cleaned with the aid of an abrasive such as emery paper either by hand or by the employment of a cutter driven, for example, by a Bowden wire. The abrasive has for its object to remove the deposits of rust or of scale that are present on the mould and which in the case of scale result from the incomplete combustion of the lubricating oil. The abrasive has in practice the inconvenience of grinding away some of the metal constituting the mould. The sharp angles of the mould are rapidly worn away so that the objects produced'by the mould no longer present the original sharp detail. Especially, seams and lines in the mould soon impart to the object moulded an inacceptable outline while the interior capacity of the mould increases until it exceeds the tolerances imposed by the customer. That process of cleaning furthermore does not permit the proper cleaning of the intaglios and other details present in the mould, such for example, as inscriptions and screw threads. The process according to the invention overcomes all these conditions.
In applying the invention to metal moulds used in glass manufacture, the object to be cleaned, for instance a perfume bottle mould, is subjected to elastic vibrations in the range specified which are applied directly or preferably through a cleaning liquid. The frequency of the vibrations may vary throughout large limits, but a frequency of 20,000 periods per second gives good results in practice both as to speed of operation, quality of work, quantity of energy consumed, and the silent operation of the apparatus. The operation is quick, complete, silent, and the energy consumed is moderate.
The liquid employed may be water, an aqueous acid solution, an aqueous basic solution, or a neutral aqueous solution; it is also equally possible to employ with advantage diverse products, such as for example, gasoline, mineral oil, benzine, and carbon tetrachloride. In general, if a particular liquid is known to have a detergent effect in connection with removal of a particular foreign body, it is useful to employ such a solution in the process of this invention. For instance prior art pickling solutions when employed in this process are of increased effectiveness when employed in accordance with this invention.
The experiments carried out by the inventor have shown that when a glass makers mould is subjected to the action of elastic vibrations in the sonoric or ultra-sonoric range, the vibrations being applied directly or transmitted by a liquid, rust and scale crumble at once and fall away from the object. This result is obtained rapidly and the metal constituting the mould remains practically intact. The process in accordance with the invention thus accomplishes by a short treatment cleaning of a mould so that its Walls are perfectly clean and have not been subjected to appreciable attack. The appearance of the walls is fully comparable to that which they possessed at the finish of the machining operation by which they were produced. The surfaces thus obtained are particularly suited to receive a protective revetment. The treatment according to the invention may be employed in advancing chemical reactions between liquids and solids, and this may be done at the same time as the cleaning of the mould, by choosing appropriate solutions, or thereafter. Thus, the inventor has shown that the vibrations described facilitate such chemical reactions. For instance, phosphoric acid solutions containing up to 45 cubic centimeters of 60 B. phosphoric acid per liter have been employed to clean a glass mould and at the same time to accomplish the phosphatation of its walls.
The following examples, in connection with the accompanying drawings, illustrate the methods and particular apparatus that are advantageous in carrying out the methods.
In the drawings,
Fig. 1 is a vertical section through an apparatus embodying the principles of the invention, dia grammatically displayed.
Fig. 2 is a vertical section through another form of apparatus.
Fig. 3 is a vertical section through yet another form of apparatus.
Figs. 1 and 2 show vertical sectional views of apparatus having vatsadapted to produce elastic vibrations of the type specified by means of emitters operating on principles of magneto-striction. The apparatus of Fig. 3 diagrammatically shows apparatus designed to produce ultra-sonoric frequencies by the aid of a piezo-electric emitter.
In the different figures like numerals apply to similar objects. Referring first to Fig. l, l is a receptacle or vat containing a liquid 2 beneath which is an emitter 3 operating on principles of magneto-striction. The emitter is constructed of a laminated bar ll made of nickel or some other magneto-strictive alloy. Around this bar are disposed a coil 4 through which a direct current can be passed and which will serveto produce a constant magnetic field when the current is turned on, and a coil 5 which is served by an alternating current which acts to produce a variable magnetic field which is superimposed on the constant field. Armatures 0 of magnetic metal enclose the two coils, and prevent the dispersion of the lines of force of the coils into the air. Because of the variations in magnetic field the extremities 7 and 3 of the bar 3 are vibrated in the direction of the arrows f and g at the frequency of the alternating current used. With the object of increasing by resonance the vibratory amplitude of the bar, one gives to the bar 3 a length equal to the length of the wave of the vibration produced. As shown in Fig. 1, there may be fixed to the two extremities of the bar 3, for example by solder, two bars 311 and 32) made of any metal at all and provided with a convenient length in order to transmit vibrations to the liquid 2 by the end 0 of the bar 3a. From this it results that the plane 0 vibrates in the direction of the arrows f. It is possible to mechanically fix the bar with relation to a nodal plane illustrated at [2 in Figure 1.
In Fig. 2 the numerals employed have the same significance described hereinabove, but in this figure the laminated bar 3, which also has the half length of the wave of vibration produced, is attached at its upper part 'i to the bottom of the vat while there has been attached to its base a bar 317. Therefore, there exists in the plane 1 of Fig. 2 a surface that vibrates in the direction of the arrows h and which communicates its vibrations to the bottom of the vat.
In Fig. 3, there has been shown at 22 a piezoelectric emitter which is made of a piece-electric substance such as a sheet of quartz, for example. There is constituted between the upper face 23 and the lower face 24 of the emitter an alternative difference of potential such that the emitter is put in vibration in the direction of the arrows i at the frequency of the current employed.
The piezo-electric emitter is placed inside a vat 1 preferably made of a material not conductive of electricity, such vat being filled with a liquid 2, the emitter being fixed by any suitable means such as, for example, the screws shown at 25 in the figure. The current is led to the lower face 24 of the emitter through the piston 26 set on a rod 2'! said piston may be brought by a convenient controlling means to a small distance from said lower face. The rod 2? is connected to a current supply line '20. The current is led to the upper face 23 of the emitter through a basket 29 containing the articles 30 to be cleaned, said basket being connected to current supply line 3!. The basket may also be brought by a convenient controlling means to a small distance from the upper face 23 of the emitter.
A general ad a-ntage of the invention is in the cleaning of objects of sort whatever. A particular advantage of the invention is in the glass making industry in the cleaning of moulds. The apparatus diagrammatically displayed is not difficult to construct and is efficient in operation. The extreme frequencies in the range described are useful in particular circumstances whereas the medium frequencies are of general utility.
As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments, except as defined in the appended claims.
What is claimed is:
l. The method of cleaning a metal object of an adhering hard deposit of different constitution, and of restoring it to its original form and size by removal of said deposit, that comprises immersing the metal object in a liquid, and subjecting the liquid contacting the object to undamped elastic vibrations propagating themselves inside of said deposit and deflecting themselves at least partially towards the inside of said deposit on the metallic surface to which the deposit adheres, said vibrations having a periodicity circa 20,000 periods per second, the values of the frequency and energy of said vibrations being chosen so as to create inside said deposit instantaneous mechanical strains greater than the rupture limits thereof.
2. The method of claim 1 in which the vibrations are within the range of 16,000 to 50,000 periods per second.
3. The method of claim 1 wherein the vibrations transmitted to the material of the deposit have a vibratory energy of about 2 watts or above per square centimeter of the acting surface of the used generator of waves.
e. The method of claim 2 in which the liquid is itself capable of acting on the deposit.
5. The method of claim 4 in which the liquid has detergent properties.
6. The method of cleaning a dense and rigid object having an adhering hard deposit of different acoustic impedance, that includes the steps of transforming an alternating current to an electromagnetic pulsation, transforming the electromagnetic pulsation to mechanical vibration within a liquid, and subjecting the object to the mechanical action of the liquid, the said current being selected and arranged to produce a magnetic pulsation rate, and the pulsation rate a vibration rate, in a wide range about 20,000 cycles per second.
'7. The method of cleaning a metallic glass mould of a solid deposit gathered in molding glass, comprising immersing said mould in a liquid, and subjecting the liquid contacting the mould to undamped elastic vibrations propagating themselves inside of said deposit, and reflecting themselves at least partially towards the inside of said deposit on the surface of the mould, said vibrations having a periodicity circa 20,000 periods per second, the values of the frequency and energy of said vibrations being chosen so as to create inside said deposits instantaneous mechanical strains greater than the rupture limit thereof.
8. The method of cleaning and phosphating a metal object that includes the step of subjecting the object to elastic, mechanical vibrations in the range between 16,000 and 50,000 periods per second in contact with phosphoric acid solution.
9. The method of cleaning and phosphating a metallic glass mold that includes the step of subjecting the mold to mechanical vibrations in the range between 16,000 and 50,000 periods per second in contact with phosphoric acid solution containing 45 cubic centimeters per liter of 60 B. H3PO4.
10. The method of cleaning a rigid impervious body comprising a foreign deposit that includes the steps of subjecting the body to mechanical vibrations in a broad range about 20,000 periods per second in contact with a cleaning liquid comprising a detergent.
11. The method of cleaning a rigid, impervious body of an adhering foreign deposit that comprises subjecting such body to elastic vibrations in a cleaning liquid, propagating themselves inside of said deposit and reflecting themselves at least partially towards the inside of said deposit on the surface to which the deposit adheres, said vibrations having a periodicity circa 20,000 period-s per second, the values of the frequency and energy of said vibrations being chosen so as to create inside said deposit instantaneous mechanical strains greater than the rupture limits thereof.
MAURICE .MARCEL EUGENE BOURGEAUX.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,290,476 Allen Jan. 7, 1919 1,738,565 Claypoole Dec. 10, 1929 2,075,237 Sexton Mar. 30, 1937 2,118,480 Somes May 24, 1938 2,246,165 Dawihl et a1 June 17, 1941 2,258,894 Janco Oct. 14, 1941 2,468,550 Fruth Apr. 26, 1949 FOREIGN PATENTS Number Country Date 213,620 Switzerland May 16, 1941