US1825226A - Deoxidizer - Google Patents

Description

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UNITED; STATES- WILK INSBURG, AND WILLIAM C. W'ILHARM, OF EDGEWOOD, PENN- JAMES G. FORD, 01

T 1T OFFICE SYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COM- PANY, A CORPORATION OF PENNSYLVANIA DEOXIDIZER This invention relates to means for removing oxygen from atmospheres contaming the same, more especially to the removal of the oxygen from the spaces above the 011 5 in electrical apparatus such as transformers, circuit breakers, like.

In such electrical apparatus it is customary to place the transformer body, or

the like, within a metal container or tank and to cover the same with a high grade insulating oil. A space is left above the oil lever to permit expansion thereof under normal operating conditions, and there is usually provided means whereby communication is allowed to the outside air, in order that upon expansion or contraction of the oil, air may be forced out or drawn in, a

phenomenon which is known as breathing. Upon an are forming in the oil, either accidentally or during the normal operation of the apparatus, combustible gases, which mix with the air in the space above the oil, are produced, forming an explosive mixture. This mixture has, on different occasions, been ignited by arcs within the apparatus, causing explosions which damaged the same, and endangered the.,lives of station attendants or workmen. Furthermore, the oxygen in the air which is breathed by the transformer, gradually reacts with the oil, forming a sludge which is detrimental to the insulating properties thereof.

In order to prevent the detrimental effects of oxygen, it has been proposed to provide an inert atmospherein the container. One of the means was to providea material through whichall the air necessary for the breathing of the transformer shall pass, the material being capable of absorbing the oxygen from the air, thus rendering the atmosphere above the oil inert and preventing the formation of explosive mixtures.

7 Our invention relates to materials of this character, it being among the objects thereof to provide a material which shall be effective in removing oxygen from atmospheres containing the same, which shall not deteriorate and which shall be reactive LIT." 37

oil switches and the Application filed December'21, 1923. Serial No. 682,098.'

under all the normal operating conditions of the apparatus.

In practicing our invention, we provide a mixture of a metal with an electrolyte and a relatively small amount of water. We utilize a metal that is capable of reacting with an electrolyte and of forming a compound or compounds that are capable of being oxidized by means of oxygen at atmospheric temperatures.

The chemically reactive constituents of a preferred composition are copper, ammonium chlorideand water. In the presence ofcertain substances such as ammonium chloride capable of producing ions in solution, certain metals, such as copper, are capable of forming oxidation products with oxygen. The use of equivalent proportions of the metal and electrolyte gives the best results. Thls is probably owing to the formation of a double salt of the two materials, one of which may be cupro-ammonium chloride and others of which may be salts of more or less complex ions which facilitate the oxidation reaction thereof.

The action may be accelerated by the ad-! dition of finely divided catalytic materiah} such as activated carbon and also by the use of highly porous inert material upon which the active ingredients are deposited. If desired, we may utilize a combination of said materials in our mixture.

We havefound that a mixture of this character, although effective at ordinary temperatures,-becomes less effective at ex-' tremely low temperatures (below 15 C.) and may cease to function if such'extreme temperatures are reached. To prevent the loss of'activity at the low temperatures, we

stance such as hydrated calcium chloride. The following mixture has been found very effectlve 1n deoxidizmg atmospheres:

A method of preparation of the above mixture which has been found suitable, is as follows: Copper oxide scale is ground and then mixed with 10% of its weight of silica, preferably in the form of kieselguhr, the mixture is then reduced with natural gas to give a mixture of finely divided copper and kieselguhr. The material is sifted to obtain particles which pass through a 200- mesh sieve, the remaining ingredients are added and mixed in an inert atmosphere of nitrogen or carbon dioxide.

This mixture is very effective for the purpose specified, in that the material does not deteriorate on standing, since there are no undesirable reactions taking place between the ingredients thereof. It is not affected by the humidity of the air and by ordinary temperature changes. It is stable up to temperatures of 120 C. and is reactive to 35 C. It will be noted that our material is effective to remove oxygen under practically all naturally occurring atmospheric conditions.

The material described herein is essentially that disclosed in the copending applica- ,tion of Maude et al., Serial No. 682,097,

filed Dec. 21, 1923, deoxidizer, and assigned to the Westinghouse Electric & Manufaetur ing Company. Our invention is directed to the addition of a substance having the desirable properties of calcium chloride, which we prefer to use, as set forth in the claims" appended hereto.

Although we have described our invention setting forth a specific embodiment thereof, various chan es may be made in the composition and t e manner of making the same, within the scope of our invention. For instance, instead of ammonium chloride, other ammonium salts such as the sulphate, fluoride, or the like, may be used. The inert material may be inorganic or or ganic, such as cork dust, sawdust, asbestos.

or other materials having the desired characteristics. The activated carbon may be omitted if desired and inert material, such as kieselguhr, substituted therefor, but there are indications that both the inert material and the activated carbon are effective in increasing the efficiency of the reaction. The carbon may be in any of its well-known forms, such as carbon black, coke dust, activated charcoal, or deflocculated graphite.

The proportions of the ingredients may be varied Within wide ranges and still produce effective mixtures.

Ve' claim as our invention:

1. A material'for deoxidizing atmospheres comprising an oxidizable metal, calcium chloride and water. v

2-. A material for deoxidi'zing atmospheres comprising copper, an electrolyte, calcium chloride and water.

3. A material for deoxidizing atmospheres comprising copper, an electrolyte, a catalizer, calcium chloride and water.

A material for deoxidizing atmospheres comprising copper, an electrolyte, a catalizer, inert material, calcium chloride and water. g

A material for deoxidizing atmospheres comprising copper, ammonium chloride, inert material, activated carbon, calcium chloride and water. 1

6. A material for deoxidizing gases capable of reacting with oxygen at normal and abnormal atmospheric temperatures which comprises an oxidizable metal, a salt of an alkali metal and a solution of calcium chloride.

7'. A material for deoxidizing gases capable of reacting with oxygen at normal and abnormal atmospheric temperatures, which comprises copper, an inert spacing material, a salt of an alkali metal and a'solution of calcium chloride.

8. A material for deoxidizing gases capable of reacting with oxygen at normal and abnormal atmospheric temperatures which comprises a mixture of finely divided copper, a finely divided inert material, ammo nium chloride and a solution of calcium chloride.

9. A material for deoxidizing gases capable of reacting with oxygen at normal and abnormal atmospheric temperatures which comprises a mixture of finely divided copper, a finely divided inert material, ammonium chloride and a solution of calcium chloride, said copper and ammonium chloride being in substantially equimolecular proportions.

10. A material for deoxidizing gases capa-v ble of reacting with oxygen at normal and abnormal atmospheric temperatures comparts of an inert material, about 2 parts of calcium chloride and about 5 parts of water r 11. A material for deoxidizing gases capable of reacting with oxygen at normal and abnormal atmospheric temperatures comprising 40 to 60 parts of a finely divided copper, a substantially equimolecular pro; portion of ammonium chloride, about 8 ZOZ. UUIVIIUM l lUNb,

parts of kieselguhr, about 2 parts of calcium chloride and about 5 parts of water.

12. In a composition for deoxidizing gases which comprises a finely divided oxidizable 5 metal, a spacing material, an electrolyte, and

a solution of calcium chloride.

' 13. In a composition for deoxidizing gases which comprises a finely divided oxidizable metal, a spacing material and an electrolyte,

a solution of calcium chloride, said solution being capable of rendering said composition chemically active at temperatures lower than 10 C.

14. In a composition for deoxidizing gases which comprises a finely divided oxidizable metal disposed upon an inert material in close union with an electrolyte capable of reacting with said metal in the presence of oxygen, and a solution of calcium chloride.

15. A material for deoxidizing atmospheres comprising a metal oxidizable at I temperatures below 120 C, calcium chloride and water.

In testimony whereof, we have hereunto subscribed our names this 17th day of December, 1923.

JAMES G. FORD. WILLIAM C. WILHARM.