US1902390A - wormley - Google Patents

Description

March 21, 1933. .J. c. WORMLEY STERILIZ ING PROCESS Filed May 9, 1931 INVENTOR Patented Mar. 21, 1933 JAMES G. WORMLEY, OF NEW YORK, N. Y.

STERHIIZING PROCESS Application filed May 9, 1931., Serial No. 536,204.

The most common commercial supply of electric current is 110-120 volt, 60 cycles alternating. Since alternating current is wholly ineffective for producing electrolysis, it is necessary to reduce such current to a direct current. For this purpose I prefer to use arectifier of the oxidized copper plate plype, but do not confine myself to this form.

prevent unpleasant shocks to the operator which might be caused by accidentally touching both anode and cathode connections at the same time, as well as to secure a better operation of the rectifier, it is necessary to reduce the voltage of the A. C. current before delivering it to the rectifier For this purpose I use a transformer which steps the voltage down sufliciently to prevent such contingencies.

Where direct current is available the voltage is usually 110 or 220. In such cases the line voltage is readily reduced to the desired pressure by the use'of suitable resistance in series with the anode. To avoid possible shocks to the operator I prefer to use a switch on the supply line which has to be held in position during the operation, thus preventing the operator from making contact with both hands and so affording a 3 current is not available I propose to use storage, or other forms of batteries for supply of electric current.

As electrolyte I use a water solution of certain salts, preferably sodium chloride and sodium carbonate. The relative proportions of these two salts, and the strength of the solution may be varied through a wide range without materially affecting the results. The function of the sodium chloride is to reduce the resistance of the electrolyte, and s0 increase the current passing from anode to cathode. The function of the sodium carbonate is to supply a chemical substance at the surface to be sterilized which is destructive to living organisms.

The object of my invention is'to rovide a rapid means of rendering the sur aces of metal articles completely sterile, and at the same time removing all adherent foreign matter, such as grease, rust, and all forms short circuit through hisbody. Where line.

of tarnish. I secure these results by the use of an electric current whereby certain chemical reactions are set up at the surfaces to be sterilized, which act both chemically and physically to destroy and remove the germs and adherent matter.

The general principles of carrying out my invention will be understood from the following description, reference being had to the accompanying drawing, in which Fig. 1 represents a diagrammatic sketch of the electric circuit when the source of supply is alternating current; and

Fig. 2 is a sectional diagram showing the preferred arrangement of'anode and cathode in the tank containin the electrolyte.

Referring to Fig. 1: B, are the connecting terminals of a source of A. C. current; C, E, the terminals of the primary coil of a transformer; D, F, the terminals of the secondary coil of said transformer;

G, H, the supply terminals of a copper plate rectifier; J, I, the positive and negative terminals respectively of said rectifier; T, a vessel containing a suitable electrolyte; K, a suitable anode; and L the article to be sterilized, which constitutes the cathode.

Referring to Fig. 2, M represents a cross section through a tank, which may be of any convenient size, and of any material 30 resistant to alkaline solutions. NN shows a section through the anode, which is referably made of a sheet of chrome-nicke steel, commercially known as stainless steel,

bent into the form indicated by the diagram. Any other insoluble conducting material, however, maybe used for the anode.

In order, to sterilize a number of articles at the same time it is most convenient to place them in a wire basket shown in cross section at 0, Fig. 2, the basket and its contents then forming the cathode. The anode and cathode are connected in any convenient manner with the positive and negative poles respectively of the direct current, as indicated in Fig. 1..

The actions which take place in the sterilizing process are as follows: when the anode and cathode are properly connected to a source of direct current, current passes from anode to cathode, thereby disassociating the oxygen and hydrogen in the water molecules, the hydrogen being set free in molecular contact with the surface of the cathode, which constitutes the surface to be sterilized. The molecules of hydrogen collect into bubbles and are dislodged by their buoyancy, and thereby detach any substance adhering to the metallic surface, such as grease, rust, or tarnish, and any microbes adhering to these substances. The result of this action is to render the surface chemically clean and completely germ free, or sterile. At the same time electrolysis of the sodium carbonate takes place, forming sodium hydrate (caustic soda) at the cathode surface, which acts destructively on all living matter.

The practical operation of the process is as. follows: a solution of common salt and carbonate of soda (sal soda or crystalized carbonate of soda may be used) in about equal proportions, is prepared, using from 2 to 4 ounces of each to the gallon of water. The solution is then placed in the tank, which it fills nearly to the top, and is preferably heated as hot as the hand can bear.

The basket, which is preferably made ofheavily tinned steel wire, is then charged with the articles to be sterilized, connected to the negative pole of the current supply by a rubber covered flexible conduit, and lowered into the tank until the contents are entirely immersed. The evolution of gas begins instantly, and in a short time, usually less than a minute, the surfaces are rendered chemically clean and sterile. The basket with its contents is then removed from the tank, when the articles are ready for use. If desired, the basket and contents may be rinsed by immersing in hot water.

The advantages of my process over the methods now in common use are twofold: the action is almost instantaneous; and is invariably complete, giving absolute sterilization together with a chemically clean surface. No harm to the metallic surface results from longer action of the process. I prefer to use 8 volts to 10 volts on the anode and cathode circuit but 1 volt will accomplish the purpose, by longer operation, and the usual supply line voltages will do no harm to the surfaces.

I claim:

1. The method of sterilizing metallic surfaces comprising, submerging the metallic surface in a receptacle containing an aqueous electrolyte solution containing sodium carbonate and inside of a U-shaped insoluble anode, connecting the anode in an electric circuit and connecting the metallic surface.

in the same circuit as a cathode sup orted within and spaced from the U- aped anode, andpassing current through the circuit and consequently the electrolyte where:

by electrolysis is set up to generate caustic soda and hydrogen at the surface of the metal and to render the cleaned surface sterile and free from microorganisms.

2. The method of sterilizing the surfaces of metallic articles having electrical conductive properties comprising, containing within a receptacle an aqueous electrolyte solution containing sodium carbonate, placing the articles to be sterilized Within a supporting cathode structure of basket shape so that the articles are in conductive contact with said supporting structure, surrounding the supporting cathode structure with a U-shaped insoluble anode structure spaced from the cathode structure and from the liquid container, and connecting said anode and cathode structures in an electrical circuit and passing current through the circuit and consequently the electrolyte where' electrolysis is set up to generate caustic soda and hydrogen at the surface of the metal and to render the cleaned surface sterile and free I from microorganisms.

Signed at New York in the county of New York and State of New York this thirtieth day of April A. D. 1931.

JAMES C. WORMLEY.

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