US1740477A

US1740477A - Protective apparatus

Info

Publication number: US1740477A
Application number: US2779A
Authority: US
Inventors: Clarence J Rodman; Charles A Styer
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1925-01-16
Filing date: 1925-01-16
Publication date: 1929-12-24
Anticipated expiration: 1946-12-24

Description

1929- c. J. RODMAN ET AL 1,740,477

PROTECTIVE APPARATUS 4 Original Filed Jan. 16. 1925 WITNESSES: INVENTORS C/are/zce JI/fodmcm and a. W 6hg ves A Sfl/cr' ATTORNEY Patented Dec. 24, 1 929 PATENT OFFICE CLABENGE J. BODMAN AND CHARLES A STYER,

OF 'WILKINSBUBG, PENNSYLVANIA,

ASSIGNORS TO WESTINGHOUSE ELECTRIC &. MANUFACTURING COMPANY, A CORPO- m'rron or PENNSYLVANIA rnorncrrvn arrm'rus Application filed January 16, 1925, Serial 110.2,779. Renewed Iay 11', 1929.

Our invention relates to oil-insulated electrical devices, such as transformers, and particularly to means for rendering the gases confined above the insulating oil inert orfree from oxygen.

One ob]ect of our invention is to provide oil-insulated electrical devices with means for deoxidizing and dehydrating air or other gas entering therein.

Another object of our invention is to provide a deoxidizing and dehydrating device a for oil-insulated electrical devices that shall be provided with suitable means for preventing the dehydrating material from rendering the deoxidizing materialdnactive by extracting the moisture therefrom.

A further object of our invention is to pro vide a deoxidizing and dehydrating. device for oil-insulated electrical devices that shall be provided with a suitably disposed barrier between the deoxidizing and dehydrating materials in order that the dehydratin compound may not deleteriously afiect t e deoxidizing material by reason of the diifusion of the gases surrounding each material and, at the same time, permitting an exchange 0 air or gas between the two materials under predetermined conditions.

Still another object of our invention is toprovide a'dehy drating or deoxidizing device for oil-immersed electrical devices that shall have the dehydrating compound disposed adjacent to the electrical devices and be separated from the atmosphere by the deoxidizing device, in "order that the moisture of the composition. liberated duringthe activity of the deoxidizing compound shall be prevented from entering the electrical device.

In the accompanying drawings,

-- Fig. 1 is a view, partially in elevation and partially in section, of an electrical translating device embodying my invention;

Fig. 2 is a view, partially in elevation and partially in section, valve; and

Fig. 3 is a sectional view of another form of valve.

Our invention comprises, in general, an electrical device 1, such as a transformer or circuit interrupter, that is partially filled f Maude,

of a modified form of with an insulating oil 2, above which is ,confined an atmosphere 3 of inert or oxygen-free air or gas, and a deoxidizing and dehydrating device 4 for rendering air or gasdrawn into the electrical device 1 inert or free from oxygen.

The deoxidizing and dehydrating device 4 comprises a casing 5, having a suitable air vent therein and within which are placed containers 6 and 7 the latter being disposed within the former, and both of which are covered by a sealing compound 8 to prevent access of the air thereto.-

The container 6 is filled with a deoxidizing compound9, the composition of which is approximately The characteristics of the deoxidizing material are described in the application of Rodman, Styer and Wilharm, Serial No. 682,097, filed'Dec. 21, 1923, and which is assigned to theWestinghouse Electric 6% Mann acturing Company.

The container 7 is filled with a dehydrating material 11, such as calcium. chloride.

A liquid seal 12 is disposed between the atmosphere and the. deoxidizing material 9, in order to prevent unnecessary decomposition of the latter by direct contact with the atmosphere, although the seal 12 permits a transfer of air or gas therethrough under certain conditions of pressure of the gas 3.

The chemical properties of the deoxidizing material 9 are such that a quantity of moisture is required for its chemicalactivity and, accordingly, a certain amount of. moisture is liberated inthe air or gas that has been treated by it. The dehydrating material 11 is therefore connected in series between the deoxidizing material 9 and the electrical translating device 1. A liquid seal or pressure regu or 13 is connected between the dehydrating material 11, and the electrical device 1, in order that the dehydrating and deoxidizing device 4 may operate at substantially air pressure, regardless of the pressure of the gas 3. Inasmuch as the dehydrating material 11 would gradually absorb the moisture contained in the deoxidizing material 9, by reason of the diffusion of the gases surrounding these compounds, it has been found advantageous to insert a barrier or check valve 1 1 in the pipe connection between the deoxidizing and the dehydrating materials.

The check valve 14, shown in Fig. 1, is so disposed as to permit air or gas to be drawn into the electrical device 1, but to prevent the escape of gas therethrough.

In Fig. 2, a check valve 15 of plate form is shown and may be substituted in lieu of the check valve 14.

In Fig. 3, there is shown a liquid seal 16 that may be substituted for the check valve 14:. The advantage of the liquid seal 16 is that it permits the movement of air or gas in both directions between the chemical compounds 9 and 11. This form of construction is particularly advantageous where it is desired to have in-breathing and outbreathing both take place through the device 4.

During normal operation of an electrical translating device embodying our invention, the volume of the oil 2 increases and decreases by reason of changes in temperature, leakage, etc., thereby causing the volume of the gas 3 to change. Inasmuch as the temperature of a transformer varies considerably from time to time during a single day, as well as with seasonal variations, by reason of the variations in the electrical energy that it is called upon to transmit, there are many fluctuations in the volume of the gas 3.

Assuming the temperature, and accordingly the volume, of the oil 2 to decrease, with a corresponding increase in the volume of the gas 3, the pressure in the tank decreases below atmospheric pressure and there is a tendency to draw in air from the atmosphere source. Air enters the open end of the pipe leading to the liquid seal 12, traverses the deoxidizing material 9 where its oxygen is removed, check valve 14, the dehydrating material 11 wherein its moisture is absorbed and the pressure regulator 13 to the gas 3. The product entering the tank 1 is accordingly substantially pure dry nitrogen. The pressure regulator is so adjusted that, when the pressure within the electrical device 1 drops slightly below that of the surrounding atmosphere, an inbreathing action takes place in order to prevent oXygen-bearing air being drawn in around the seams of the device 1.

Upon a decrease in the volume of the at-" mosphere 3, the check valve 14 prevents the out-breathing of gas from the device 1, and

Fig. 3, is employed, the escaping gas travv erses the pressure regulator 13, the dehydrating material 11, the valve 16, the deoxidizing material 9 and the liquid seal 12 in a direction opposite to that shown by the arrows. The pressure regulator 13 is so ad justed as to require a considerable pressure of the atmosphere 3 to be present before permitting out-breathing.

It will thus be seen that we have devised a dehydrating and deoxidizing device in which the advantages inherent to the deoxidizing compound and the dehydrating compound are utilized without permitting the moisture, incidental to the operation of-the deoxidizing compound, to enter the electrical devices and, at the same time, preventing the dehydrating compound from unnecessarily rendering the deoxidizing compound inactive by absorbing the moisture therefrom by reason of diffusion of gas therebetween.

While we have illustrated but one embodiment of our invention, it will be apparent to those skilled in the art that various changes and modifications may be made in the apparatus illustrated without departing from the spirit and scope of our invention, as set forth in the appended claims.

We claim as our invention:

1. In combination, an electrical device comprising a casing, a deoxidizing compound and a dehydrating compound disposed between the atmosphere and the casing in the order named, and means for sealing said compounds from each other under predetermined conditions.

2. In combination, an electrical device comprising a casing, a deoxidizing compound and a dehydrating compound disposed between the atmosphere and the casing in the order named, and means for sealing said compounds from each other under predetermined conditions, said sealing means permitting a transfer of air or gas between said compounds under other conditions.

3. In combination, an electrical device comprising a casing, a moist deoxidizing comorder named, and means for preventing the absorption of the moisture from the deoxidizing material under certain conditions, said means permitting a transfer of air or gas between said compounds under other conditions 5. In combination, an electrical device comprising a casing, a'moist deoxidizing compound and a dehydrating compound disposed between the atmosphere and the casing in the order named and means for preventing the absorption of the moisture from the deoxidizing material under certain conditions, said means permitting a transfer ofair or, gas to the casing under other conditions, whereby said deoxidized air or gas is brought into contact with the dehydrating compound before entering the casing. r

6. The combination of a casing, a moist deoxidizing compound and a dehydrating compound, the dehydrating compound being so disposed relative to the casing and the deoxidizing compound as to remove the hygroscopic moisture from all air or gas entering the casing, of means for preventing the absorption of the moisture from the deoxidizing compoundunder certain conditions. I

7 The combination with an interconnect ed deoxidizing compound of a moist material and dehydrating compound, of means for preventing the dehydrating compound from absorbing the moisture of the deoxidizing material, said means permitting the interchange of air or gas between said compounds under predetermined conditions.

; 8. The combination with an interconnected deoxidizing compound of a moist material and a dehydrating compound, of means for preventing the dehydrating compound from absorbing the moisture of the deoxidizing I material.

9. The combination with a deoxidizing compound having a moistened air or gas in contact therewith and a dehydrating compound in series connection therewith, of

{means for preventing the absorption of the hygroscopic moisture adjacent to the deoxidlzing compound by the dehydrating compound, said means permitting an exchange of air or gas between said compounds under abnormal conditions.

In testimony whereof, we have hereunto subscribed our names this 18th day of December, 1924.

CLARENCE J. RODMAN.

5 CHARLES A. STYER.