Untitled record

(No Model.)

Sheets—Sheet 1.

M. PRIDHAM,

APPARATUS FOR GENERATING OZONE.

No. 574,341.

Patented Deo. 29, 1896.

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THE NORRIS PETERS CO.. PHOTO-LITHO., WASHINGTON. D. C.

(No Model.) 2 Sheets—Sheet 2.

M. PRIDHAM.

APPARATUS FOR GENERATING OZONE.

No. 574,341. Patented Deo. 29, 1896,

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THE MORRIS PETERS CO. PHOTO-LITHO.. WASHINGTON. O. C.

United States Patent Office.

MARSHALL PRIDHAM, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE ELECTRIC RECTIFYING AND REFINING COMPANY, OF CAMDEN, NEW JERSEY.

APPARATUS FOR GENERATING OZONE.

SPECIFICATION forming· part of Letters Patent No. 574,341, dated December 29, 1896.

Original application filed September 12,1896, Serial No. 605,632. Divided and this application filed October 15, 1896, Serial No. 608,987. (No model.).

To all whom it may concern:

Be it known that I, Marshall Pridham, a citizen of the United States, residing at Philadelphia, county of Philadelphia, Pennsyl5 vania, have invented certain new and useful Improvements in Apparatus for Generating Ozone, of which the following is a specification.

My invention consists of an apparatus for io generating ozone gas, whereby the quantity of gas produced and the purity of the product are greater than with other processes with which I am familiar, the mode of operation consisting, essentially, in subjecting oxygen 15 gas to an electric current in the form of a brush-discharge, the oxygen and gas being, by preference, at a low temperature while it is being subjected to the action of the current.

In the accompanying drawings, Figure 1 is 20 a side view, partly in section, of apparatus constructed in accordance with my invention for the production of ozone. Fig. 2 is a longitudinal section, on a larger scale, of the generator proper. Fig. 3 is a transverse section 25 of the same, and Fig. 4 is an exaggerated view illustrating more clearly than the other figures the character of the conducting-surfaces with which the generator is provided.

In the drawings, A represents a tank or res30 ervoir for containing oxygen derived from any suitable source, this tank being connected by means of a pipe a to the ozone-generator C, between which and the tank A is a refrigerating or cooling tank B, through which the 35 pipe a passes on its way to the generator C, a portion of said pipe a being preferably spirally coiled in the tank B and surrounded therein by a refrigerating liquid or cooling medium, such, for example, as ammonium 40 nitrate and water.

Instead of passing the oxygen gas through a cooling medium I may compress the same, and after permitting the compressed gas to cool to any desired extent may then permit it 45 to expand either directly into the ozone-generator or into a supply-chamber therefor, thereby greatly decreasing its temperature, and thus cooling it to the desired degree.

The generator C consists of a casing c of dielectric material, preferably glass, and pref- 50 erably also in the form of a tube or pipe closed at each end by suitable caps c', that at one end of thecasing being provided withaperturesc” and c^i!i, while that at the other end of the casing is provided with apertures c^iv and c^v. 55 Within this outer casing is another casing or box/preferably of metal and of smaller external diameter than the internal diameter of the outer casing, this inner casing being centrally supported within the outer casing, so as to 60 provide a uniform width between the cylindrical portions of the two. Within the inner casing is a spraying device consisting, in the present instance, of a perforated metal tube d, closed at that end which is within the inner 65 casing, but open at the outer end, the tube passing through the aperture c“ in the cap o', which aperture is preferably provided with a suitable stuffing-box, the outer end of the tube being connected with any suitable supply of 70 cooling liquid, which may be admitted to or cut off from the tube d, as desired, by means of a valve V.

Connected to the inner casing b, preferably at one end, is a discharge-pipe e, which 75 passes through the packed aperture c^v into the chamber of a suitable ejector E, having a motive-fluid-supply pipe e', and is intended to be used for draining the internal chamber of said casing b and thereby preventing the 80 accumulation therein of fluid in such quantity as would interfere with the spraying action of the perforated tube d.

Communicating with the space between the inner and outer casings of the generator is a 85 pipe/, which is fitted to the aperture c^iv and serves to convey the ozone gas to any suitable reservoir or treating-chamber, the oxygen-gas-supply pipe a passing through the aperture cⁿⁱ in the opposite head c' of the 90 generator.

The outer surfaces of both the inner and outer casings of the generator are coated with a layer t of material suitable for producing a brush-discharge, such material, for instance, 95 as powdered carbon, lead dust, or the like, which will produce a surface of roughened or granulated form, presenting a multiplicity of g

574,341 points or protuberances. The layer or coating of granular or powdered material may be applied to the surface of the casings by coating the latter with an adhesive non-conduc5 tive material and sprinkling the said powdered or granular material thereon.

To the coatings of the inner and outer casings of the generator are connected the terminals of the secondary coil of a step-up io transformer supplied with a suitable current of electricity, preferably an alternating current. The terminal k' is connected to the outer surface of the inner easing and the terminal k is connected to the outer surface of 15 the outer easing. Hence when the current is turned on a brush-discharge takes place from the coating of the inner casing through the dielectric outer casing to the outer coating of the latter, and the oxygen gas passing 20 through the annular space between the two casings is subjected to the action of this induced brush-discharge, the low temperature of the gas being maintained by the cooling fluid which is sprayed upon the inner casing 25 from the tube d.

By subjecting oxygen gas to an electrical current in the form of a brush-discharge I find that ozone of a very high degree of strength can be economically and rapidly pro30 duced, and I find, further, that the process is facilitated by a low temperature of the ozone gas. Hence I prefer in all cases to cool the gas before it enters the generator and to maintain it at low temperature in said generator. 35 This brush-discharge consists of a great number of sparks passing and repassing between the two coated casings and extending from the numerous protuberances or points formed by the granular or powdered coating.

In practice I have used temperatures below zero Fahrenheit, and I find that, as a rule, the lower the temperature the better the result.

I also prefer in carrying out my invention 45 to use an oxygen gas of as pure a character as can be manufactured on a commercial scale within the necessary limit of cost, although my invention may be carried out successfully even if the oxygen gas is diluted or 50 adulterated to some extent by admixture with air or with other gases.

I may state that while the process and apparatus for generating ozone are particularly adapted for use in connection with my im55 proved process of purifying and decolorizing saccharine and other liquids, as disclosed in my application for Letters Patent, Serial No. 605,441, filed September 10, 1S96, and Serial No. 605,631, filed September 12, 1896, and 60 with my improved process of purifying, rectifying, decolorizing, and deodorizing alcoholic and other liquids, as disclosed in my application for Letters Patent, Serial No. 605,632, filed September 12,1896, of which the .65 present is a divisonal application, my present invention is capable of general application wherever ozone gas is required. I should also state that while it is necessary in all cases to make the outer casing dielectric the inner casing may or may not be dielectric, 70 though I prefer to make the latter casing of metal or equivalent material,especially where the cooling medium is sprayed against it, in order that it may the better withstand the shocks of the streams of cooling fluid im- 75 pinging said casing.