US1378599A - Process and apparatus for making electrodes - Google Patents

Description

W. G. MICHEL.

PROCESS AND APPARATUS FOR MAKING ELECTRODES.

1 APPLICATION FILED 050.17.1919.

1,37 8,599. Patented May 17, 1921.

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MI HI I I I Mum/Y 6: /7/(#4 UNITED STATES PATENT OFFICE- PROCESS AND APPARATUS FOR MAKING ELECTRODES.

Specification of Letters Patent.

Patented May 17, 1921.

Application filed December 17,1919. Serial No. 345,85

i To all whom 'it may concern:

Be it known that I, WILLIAM G. MICHEL, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements in Processes and Apparatus for Making Electrodes, of which the following is a specification.

The object of this invention is to provide new and improved forms of electrodes and abrasives and a process for makin them.

This and other objects of the lnvention will be fully illustrated in the drawings, described in the specification and pointed out in the claims at the end thereof.

In the accompanying drawings,

Figure 1 is a diagrammatic v1ew of the apparatus for making the electrodes.

Fig. 2 is a view of the tube or mold in which the electrode or abrasive is made.

In the drawings, like reference numerals indicate like parts.

It will be understood that electrodes have heretofore been made of pulverized coal, or graphite, or coke, or charcoal, or other suitable conductors that are more or less proof against corrosion by electrolytes. These electrodes must be formed to certain desirable shapes and can best'be formed in those shapes by reducing the conducting material of the electrode to small pieces or pulverized condition and compressing them together and then binding these pieces together by a suitable binder, such as tar, pitch, oil or shellac, which binding material is ordinarily non-fluid -or congealed when cold and is in a fluid condition when hot.. This process must also be followed in preparing abrasives such as hones, polishing or grinding wheelsand the like.

11 preparing electrodes, I. therefore take the desired conducting material and reduce it to the proper condition of fineness and compress it in the desired form intoasuitable receptacle. I then brin the binder into intimate contact therewit under conditions of suitable temperature and pressure so as to secure an intimate mixture of the binding material with the conductor '50 that cohesion between them will be properly and effectively secured. For the purpose of *this heat and pressure treatment I 'provide the following apparatus.

In the drawings, reference numeral 1 indicatesan elevated tank in which an aginate the electrodes.

tator 2 is mounted to move to stirup and mix the in redients that are contained in the tank. 11 this tank is placed the binding material for the electrodes, which bindlng material will depend upon the use to which the electrode will be put and consists of elther tar, pitch, oil or shellac or a combination'of them. The tank l is heated and the agitator operates to mix and secure the even heating of the materials therein until it is reduced to a suitable fluid consistency. After this is done, the fluid is drained off through the pipe 3 into the reservoir 4 which is also heated in order to keep the contents in a liquid state.

The material for the electrodes is formed in suitable forms or molds such as'pipes having one end thereof closed and the other end open. One of these forms indicated by the reference numeral 5 is shown in Fig. 2. The material for the electrode such as pulverized coal or graphite or coke or charcoal, is placed in the pipe or mold. It will be understood that a great variety of shapes may be used for this purpose.

number of these molds are filled with the proper ingredients, and they are then placed in a boiler 6 in an upright; position therein, a man hole 17- being provided in the boiler for this. purpose.

After a suitable number of molds has been placed therein the boiler is hermetically sealed and the air is exhausted therefrom by a vacuum pump through a pipe line 7, in which pipe line is placed a trap 8. After a suitable vacuum has been created in the boiler 6, the valve 9 is opened permitting the fluid binder contained in the the electrodes, pressure may beapplied to it to make it the more completely impreg- For this purpose, the valves 10 and 11 are closed andthe valves 12, 13 and 9 are left open and air pressure is then'applied to the boiler 6 fromthe storage tank 14. This causes the. fluid to fill the forms under pressure and more com- I pletely penetrate the interstices in the elec I trodes. A gage glass is provided which shows the level of the binder in the boiler so that the correct amount may be supplied to the boiler. This glass will also show when the absorption of the binder by the electrodes has been completed.

After the filling of the electrodes has been completed, the valves 9 and 12 are closed and the valve 15 is opened and the air pressure from the tank 14 will cause the fluid to flow through the pipe 16 to the agitator tank 1, emptying the boiler 6. The air pressure is kept on and the boiler is kept heated in any suitable manner for four hours or more, after which the binder is again admitted and the pressure isapplied and the above treatment is repeated after the excess binder has been finally expelled. It will also -be understood that the reservoir and agitator tank will be keptheated in any suitable manner as by steam coils or electric conductors. The man-hole 17 may then be opened and the molds containin the electrodes may be removed after whic the molds are placed in an oven or furnace and are subjected to a high temperature causing the baking of the electrodes. After the electrodes have been baked suflicientl to make them hard, they can be removed rom the forms and are ready for use.

It will be understood that the tank 1, the,

reservoir 4 and the boiler 6 are kept-constantly heated in order to keep the binding material in a liquid state. he air storage tank 14 may also be heated so that the fluid binder will not be chilled by cold air being allowed to come in contact with it.

For the purpose of heating the binder, steam heat is used, the steam being at a pressure of about 80 lbs. with a correspondin temperature.

he air pressure which is used for forcing the binder into the electrodes may be anywhere from about 125 lbs. to as much as 1,000-lbs. or even higher.

.For making a graphite electrode, I prefer a binder WhlCl] 1s made of 25% crude oil and coal tar. For coke electrodes, I prefer a binder made of 50% pitchand 50% coal tar. For coal electrodes, I prefer from 25% to 33%% crude oil and66% tar. For charcoal electrodes, I prefer 75% coal tar and 25%. kerosene oil. For abrasive, such as emery and carborundum, for the purpose of forming stones or hones or wheels therefrom, and more especially where the wheels are coarse and slow running, I prefer a binder madeof'100% pitch or tar. For high speed wheels I prefer 100% shellac, it being understood that the same process that is used for maklhg electrodes is also used for making abrasive stones or abrasive wheels,

the binder being selected in each individual case.

It will also be understood that some of these electrodes are to be used in the presence of chemicals and the binders must be such as will resist chemical action therefrom and other electrodes will be used exposed to heat and the binder must be such as will resist the eifect of heat.

I claim:

1. An electrode composed of dry carbon, the particles of car on being held together by a fluid hydrocarbon mixed therewith and baked to a solid mass, said fluid being heated and mixed with the carbon b vacuum and pressure.

2. he process of making electrodes which consists of (1) reducing the material for the electrode into powdered form, (2) filling suitable molds with said powdered material, (3) exhausting the air which occupies the interstices between the powdered particles by subjecting the mold and its contents to a partial vacuum, (4) filling the voids created by the partial vacuum between the powdered particles in the mold with a liquid binder, said liquid binder being forced into the mold under pressure.

3. The rocess of making electrodes which consists 0? (1) reducing the material for the electrodes into powdered form, (2) filling suitable molds with said powdered material, (3) placing the filled molds into a hermeticallyr sealed boiler, (4) exhausting the air fromsaid boiler surroundin said molds in order to exhaust the air filing the interstices between the powdered particles, (5) introducing a liquid binder into the partial vacuum created between the powdered particles, (6) forcing said liquid binder between the interstices of said powdered articles.

ulverized 4. The process of making electro es which material from one another and then allowing a binder inits liquedfied form to occupy the voids thus created between the powdered particles, air pressure being used to unite the inder with the powdered particles to, form ahomogeneous mass.

7. The procem of making electrodes which consists of (1) filling suitable molds with powdered electrode material, (2) exhausti the air from between the interstices of sai owdered material in said mold, (3) introucing a liquid binder into said mold to fill the interstices between said powdered matecreated between the powdered rial, (4) compressing said powdered matethe interstices between said powdered matc- 10 rial with said liquid material bymeans of rial, (4) compressing said powdered matecompressed air introduced into said mold. rial with said liquid material by means of 8. The process of making electrodes which compressed air introduced into said mold, consists of (1) filling suitable molds with (5) the application of heat to the outside of powdered electrode material, (2) exhausting the mold after the powdered material and 15 the air from between the interstices of said lts binder have been compressed. powdered material in said mold (3) intro- In testimony whereof I aflix my signature. ducing a liquid binder into said mold to fill WILLIAM G. MICHEL.

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