US 2973312 A
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J. R. LOGAN S FOR Feb. 28, 1961 METHOD AND ME ULTRASONIC ACTIVATING OF SOLVENT AND SAND SOLUTION Filed Feb 4, 1958 uomsom mm Om INVENTOR.
JAMES R. LOGAN ATTORNEY were! raised 1 METHOD AND MEANS FOR ULTRASONIC ACTI- VATING F SOLVENT AND SAND SOLUTION Filed Feb. 4, 1958, Ser. No. 713,251
4 Claims. (Cl. 208-11) This invention relates to ultrasonic cleaning methods and means. While not limited thereto it is especially advantageously used in oil removal both in degreasing small machine parts and the like and in recovering oil by extraction from oil bearing aggregate materials such as sand, clay, silt and similar materials.
An object of the invention is to provide improved methods and means for accomplishing ultrasonic cleaning.
Another object is to provide a novel method and means for removing oil from such elements as those hereinbefore described.
Another object is to provide a cleaning method in which the ultrasonic wave energy is more efiiciently utilized. In the past when an article or element was to be cleaned ultrasonically, it was simply immersed in a liquid which was ultrasonically activated to produce cavitation. The elements were permitted to rest on the container bottom and on top of one another; but doing this has several undesirable eifects. The articles to be cleaned almost always have a different acoustic impedance than the cleaning liquid resulting in reflections of the wave so that little or no wave energy reaches certain areas of the elements to be cleaned. Moreover, the reflections often create standing waves in the fluid which prevent cleaning even in some areas which are reached by the ultrasonic waves. Different loading of the cleaner and different placement of the load with each use make it virtually impossible to overcome the problem by design change in the cleaning apparatus.
However, in the invention the problem is substantially solved, and certain of these objects are realized, by dropping the soiled elements down through a column of cleaning liquid which is ultrasonically cavitated and letting those elements tumble and turn whereby all surfaces will be contacted by the cavitating liquid. Advantageously the liquid is circulated past the elements in the direction counter to element movement so that the liquid is always fresh and so that the cleanest elements are immersed in the cleanest liquid. The liquid should be a solvent for the soil.
The time required for ultrasonic cleaning is very short but in previous methods much of this advantage is lost because of the necessity for repositioning the elements being cleaned or for extending the cleaning period in the hope that areas in which cleaning is less eifective will eventually become clean. Another object of the invention is to utilize the rapid cleaning action of ultrasound and to accomplish more uniform cleaning.
Other objects and advantages of the invention will hereinafter appear.
The following is one specific example of the process:
lulped oil sand is continuously dropping into a column of kerosene which is subjected for a vertical distance of approximately ten feet to cavitation by ultrasonic action. The cleaned sand is continuously collected at the bottom of the column and is lifted upwardly to a height above the liquid column. The kerosene column is continuously changed by flowing kerosene down through the rising sand and thence up in the column to its upper level where the kerosene and oil are removed.
The accompanying drawing is a schematic showing of a system of apparatus for practicing the invention which embodies the invention and which is advantageously used in practicing the method described in the example, it being understood that various modifications may be made in the process described and that other process, systems, and apparatus embodying the invention may be practiced and made without departing from the spirit of the invention or the scope of the appended claims.
Referring to the drawing, the system there shown comprises means for containing a vertical column of liquid solvent, means for ultrasonically activating the solvent to produce cavitation, means for dropping elements to be cleaned into the solvent, means for collecting the cleaned elements and transporting them above the liquid level, and means for flowing the solvent in a direction counter to element movement.
Advantageously the system comprises an elongated container vertically disposed, such, for example, as the cylindrical tank It? having a solvent outlet 12 near its upper end, a solvent inlet 14 near its lower end, and a solvent inlet and element collecting point 16 at its bottom end. Conveyor means in convenient form, and here shown as an enclosed auger 18 beginning at the collection point 16, extends upwardly at an angle to a level above the solvent outlet 12. where cleaned elements, such as the sand illustrated, are discharged at an opening 20 into a collection hopper 22.
Clean solvent, such as the kerosene shown, is intro duced at fill pipe 24 to a storage tank 26 having two outlets 28 and 39, including control valves 32 and 34 which are connected to inlet 14 and inlet 36 respectively. Inlet 36 is in the conveyor housing 38. The solvent flows down past the conveyor auger, and through inlet 114,- into the lower end of container 10 and thence up in the container to outlet 12 where it is pumped away by a suitable pump at The pump and valves 32 and 34 are adjusted to maintain the liquid level in the container 10 near its top as shown.
A plurality of transducers, such as the magnetostrictive transducers 42 illustrated, are attached in wave transmitting relation, as for example by welding, at vertically spaced points along one side of container 10. The transducers are connected as shown to an electrical ultrasonic wave generator 44 which, in turn is energized by a source of electrical power 46.
In operation of the system, oil sand contained in hopper 48 is passed to a conveyor 50 driven by prime mover 52 from whence it is dropped into container lit whose solvent is subjected to cavitation by the action of transducers 42. The sand falls freely down through container 10 and its solvent, tumbling and turning. The oil is extracted and removed from the sand by the cavitation action and is thereupon dissolved by the solvent. Collecting at the bottom of tank 10, the sand is picked up by auger 18, which is turned by its prime mover 54, and is elevated out of the solvent and then falls out of opening Zti into hopper 22..
During this action solvent flows counter to the sand movement as previously described.
As it is used herein, the word ultrasonic refers to mechanical wave action and does not refer to a wave action limited to any frequency or frequency range within or without the range of audible frequencies.
1. The method of removing oil from oil bearing elements which comprises dropping said elements into a solvent for oil, permitting said elements to fall free Fatented Feb. as, 19st through said solvent, and ultrasonically activating said solvent to the degree necessary to cause cavitation in the solvent as the elements so fall through it.
2. -Themethocl defined in claim 1 in which the solvent is made to flow upward as the elements fall through said solvent. 7
3. The continuous process for removing oil from oil bearing elements which comprises dropping a continuing supply of said oil bearing elements into a solvent for the oil, permitting said elements to fall free through said solvent, ultrasonically activating said solvent to the degree necessary to produce cavitation in the solvent as the elements so fall through said solvent, collecting the fallen elements and continuously elevating said elements to a level above the level of the solvent.
4. The process defined in claim 3 in which the solvent is caused to flow continuously downwardly around the elements being elevated and thence upwardly through the falling elements.
References Cited in the file of this patent UNITED STATES PATENTS 1,791,797 Clark Feb. 10, 1931 2,545,938 Bilbe Mar. 20, 1951 2,559,257 Obey July 3, 1951 2,722,498 Morrell et a1. Nov. 1, 1955 2,742,408 La Porte Apr. 17, 1956 2,825,677 Coulson Mar. 4, 1958 2,871,180 Lowman et a1. Jan. 27, 1959 Notice of Adverse Decision in Interference In Interference No. 93,484 involving Patent No. 2,973,312, J. R. Logan, Method and. means for ultrasonic activating of solvent and sand solution, final finclgment adverse to the patentee was rendered. Oct. 15, 1964, as to claim 1.
[Ofioial Gazette Decembea" 22, 1964.]
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