US1449991A - Method of and means for counteracting destructive electrolysis - Google Patents

Description

Mar. 27, 1923. 1,449,991..

L. O. GUNDERSON. METHOD OF AND MEANS FOR COUNTERACTING DESTRUCTIVE ELECTROLYSIS.

FILED NOV-4,1921.

rnwfem [MS ZQWSOIZ i: g II Pate'pted Mar. 27, 1923.

UNITED STATES LEWIS O. GUNDERSON, OF DECATUR, ILLINOIS.

METHOD OF AND MEANS FOR COUNTERACTING DES'IRUCTIVE ELECTROQYSIS.

Application filed November 4,1921. Serial No. 512,803.

To all whom it may concern:

Be it known that I, LnwIs O. GUNonnsoN, a citizen of the United States, residing at Decatur, county of Macon, State of Illinois, have invented a new and useful Improvement in a Method of and Means for Counter-acting Destructive Electrolysis, of which the following is a specification.

This invention relates to a novel and improved method of and means for counteracting destructive electrolysis either in galvanic or thermal form which often prevails in steam boilers, especially when in service; this invention being primarily directed toward preventing pitting and corrosion of the metal plates or flues of steam boilers and condensers; and in attaining the desired end this invention takes advantage of the existence of the high discharge potential of hydrogen on certain metals like arsenic when subjected to electrolytic action.

It is well-recognized that much of the corrosion and consequent decomposition of the internal surfaces of a steam boiler in service is due to the setting up of electrolytic action upon the exposed internal surfaces of the boiler, brought about by two predominant conditions, namely, thermoelectrochemical action in the boiler as a consequence of the difierence in temperatures between separated points in the boiler; and electrolytic action established by the difference of potential between the basic metal of the boiler structure and impurities lodged in or upon the surface of said basic metal. The combined thermal and galvanic actions join to produce destructive results and often are the hidden cause of boiler failures in service.

With these conditions in view it is the principal aim of this invention to provide means for counteracting the electro-chemical actions pointed out above to prevent corrosion and pitting, by the provision of a simple, economicaland effective method of neutralizing and counteracting all destructive electrolysis within the boiler, by applying an electric current to the boiler water and plating out arsenic, or other metal having a high discharge potential of hydrogen, into all internal surfaces of the boiler structure thus establishing what I shall term a secondary cathode, and means for carryin out this method, whereby the I boiler may be fortified against the deleterious effects pointed out, and whereby the boiler may, whether in service or not, be protected against the injurious effects of corrosion or pitting, or at least the effects p be reduced.

In attaining the desired end, it is necessary to cope with the conditions prevailing due both to the electro-thermal action or general electrolysis thus converting the boiler into a large galvanic cell; and the localized galvanic action .set up at the joints between the various elements of the boiler structure. In overcoming the action which converts the boiler into a galvanic cell, making anodes and cathodes out of the various structural elements, I introduce a plating bath into the boiler, composed of the ordinary feed water and a solution. of some salt of arsenic or other metal having a similar high discharge potential of hy drogen to form an electrolyte. Then suitable electrodes are placed in the boiler and an electric current is passed through the electrolytes with the boiler structure as the cathode; thus plating all the exposed interior surfaces with metallic arsenic. When this is completed the electrolyte is replaced with ordinary boiler feed water and the electrodes are permitted to remain, and while in service, the current supplied to these electrodes serving to counteract the localized currents developed at joints; the electrodes being placed at advantageous points throughout the boiler. The electric current introduced into the boiler from an 9 outside source also serves to combat the action of the boiler as a galvanic cell in service, and prevents redissolving or impairing of the protective plating of arsenic. The arsenic surface acts as cathode for the current passed thru the boiler water from the said electrodes and the boiler shell acts simply as a conductor for the return current to the negative pole of the electric generator or other source of current. The

rent from the said electrodes.

A concrete example of one application of the present invention will be illustrated and described later, this being but one adaptation of the method and illustrating one way of carrying out the method, it being obvious that no material alterations in the boiler structure are required.

Other objects and advantages of this invention and a more complete understanding of the same may be had from the fol-. lowing detail. description, and the accompanying drawing, in which r Figure 1 is a fragmentary, side elevation of a steam locomotive boiler, illustrating partly diagrammatically one circuit arrangement embodying this invention.

Figure 2 is an enlarged perspective view of one of the electrodes.

Figure 3 is an enlarged vertical section taken on line 3-3 of Figure 1, looking in the direction indicated by the arrows.

Referring more particularly to the. method "involved in this invention and the steps to be taken and structure employed here for carrying out the method, the boiler, designated 10 in its entirety, is prepared for service by filling to the required level with water; then 'the desired quantity of'arsenic salt or similar metallic compound is introduced into the water and dissolved therein to afford an eflicient electrolyte or lating bath; then the electrodes, one of whic is indicated at 11, are introduced and submerged in the electrolyte, but insulated from the metallic parts of the boiler, these electrodes being preferably placed in proximity to the parts most easily affected by pitting or corrosion caused by localized galvanic actions. Then the positive pole of a source of unidirectional current is connected to the electrodes, and the negative side grounded to the boiler shell. A current of the proper intensity is then sup-plied to the electrodes, and due to the conversion of the boiler into a cathodic element, the arsenic will be extracted from the electrolyte and plated upon the exposed interior metallic surfaces of the boiler. The plating step is carried on until a suflicient degree of plating has been accomplished, to be determined by experiment, and when completed, the boiler and its internal parts are ready for service. While in service the counter current from the outside source should be maintained to combat the localized galvanic actions referred to, but the counter E. M. F. may be dispensed with when the boiler is dead, for the reason that the arsenic plating, or secondary cathode as I term it, compensates for the general electrolytic action in the boiler.

The drawing illustrates a standard locomotive boiler composed of the fire box 13 defined by the boiler heax1-(not shown), flue sheet 14, and crown sheet 15; flue section 16, defined by flue sheet 14 and flue sheet 17; and the smoke box 18, defined by the front end of the boiler and the flue sheet 17, the boiler shell 19 inclosing the fire box and flue sections. The engineers cab 20 is provided as usual and may contain the controls for the circuitto be presently described.

The electrodes 11 are connected, through suitable insulatedhconductors 21, preferably asbestos covered, with the insulated at a convenient point. An insulated conductor 23 extends from the pressure plug 22,

-conductorssupplying current from the conventional turbo-generator 28 to the'headlight 29. The conductor 23 is then connected to the positive side of the generator through the conductor 28' lying in said conduit, and the boiler shell 19 connected to the negative side of the generator by grounding the negative side of the latter at 29. It will be understood that the rheostat and fuse may be placed in the cab 20 at a point convenient to the engineer. It will thus be noted that a current will flow through the electrolyte to the boiler shell as pointed out hereinbefore.

While various types of electrodes may be used, I prefer to provide the construction best shown in Figure 2, wherein the electrode comprises a bar 11 of iron or carbon axially carried in spaced insulating blocks or disks 3030, of bakelite. A suitable binding post 31 may be provided at one end of the electrode for securing the conductor thereto. The electrodes may be made of soluble or insoluble material such as carbon or iron, as they will, of course, require renewal from time to time. As shown in Figures 1 and 3, the insulating blocks of the upper electrodes rest upon adjacent fiues 3232, which as is conventional are-secured in the flue sheets 14 and 17, and the lower electrodes are placed in the bottom of the boiler. An'ynumber and any disposition of electrodes may be had to suit the particular occasion.

From the foregoing it will be observed that this invention provides a counter E. M. F. for overcoming the inherent electrolytic action in the boiler, and that the arrangement for plating or providing the secondary cathode serves a three-fold purpose, namely, deposits the secondary cathode on the internal parts of the boiler; counteracts pressure plug 22, secured in the boiler shell 19' I thereby stopping all deleterious electrolysis in the boiler.

Itwill be understood that minor changes in structure to suit various operating conditions may be made within the purv ew of the invention and scope of the claims.

I claim: 1

l. The method of preventing decomposltion of the internal metallic surfaces of steam boilers, which comprises, introducing into the boiler a solution of boiler water and arsenic in soluble state, to form an electrolyte, thensetting up an E. M. r in the electrolyte in a direction for deposlting the arsenic out of the solution upon the interior exposed surfaces of the boiler,

2. The method of preventing decomposition of the internal metallic surfaces of steam boilers and thelike, which comprises introducing into the boiler a solution of boiler water and arsenic in soluble state, to form an electrolyte, then setting up an E. M F. in the electrolyte in a direction for depositing the arsenic out of the solution upon the interior exposed surfaces of the boiler and maintaining said E. M. F. while the boiler is in service to make the exposed internal surface of the boiler structure a cathodic element.

3. The method of. preventing decomposition of the internal metallic surfaces of steam boilers and the like, which comprises introducing into the boiler a solution of boiler water and arsenic in soluble state to form an electrolyte, then setting up an E. M. F. in the electrolyte in a direction for depositing the arsenic out of the solution upon the interior exposed .surfaces of the boiler and maintaining said 1*]. M. F. while the boiler is in service to make the exposed internal surface of the boiler structure a cathodic element, then submerging an electrode in said electrolyte, and then sending an electric current through the electrolyte, from said electrode to the boiler structure for depositing out of said electrolyte the arsenic upon the internal exposed surfaces of the boiler structure.

passing an electric current through the electrolyte from the electrode to the boiler shell for plating the latter with the metal of the v electrolyte for counteracting galvanic action in the boiler, and then continuing the current to overcome stray electric currents and thermo-electric currents in the boiler and to prevent disintegration of the plating.

' 5. The combination with a boiler having a plurality of flue tubes, of an electrolyte placed in said boiler and consisting of water and a quantity of metal dissolved therein, means for separating said metallic salts out of the electrolyte and for plating the interior exposed metallic parts of the boiler, and said means also serving to maintain said plating against disintegration while the boiler is in service.

6. The combination of a boiler having a plurality of flue tubes, of an electrolyte placed in said boiler and consisting of water and a quantity of metal dissolved therein, and means for applying an electric current to the electrolyte for converting the boiler shell into a cathode and depositing said metallic salts out of the electrolyte upon the interior. metallic parts of the boiler.

7. The combination with a boiler having a plurality of flue tubes, of an electrolyte shell, said electrodes constituting anodes, and

the boiler shell a cathode whereby to counteract the electrolytic action .in the boiler and to overcome localized currents at said joints.

8. The combination with a boiler having a plurality of flue tubes said boiler adapted to contain ordinary feed water placed in said'boiler in service, of a plurality of movable metallic or carbon electrodes insulated from the boiler structure and submerged in said boiler water which acts as an e ectrolyte, said electrodes being disposed against surfaces of the interior parts of the boiler most affected by pitting and corrosion, a plating of arsenic, or other metal having a high discharge potential of hydrogen on all internal surfaces of said boiler structure, a source of electric current connected to the electrodes and boiler shell, said electrodes constituting anodes, and said boiler shell acting as a conductor of the said current from the plated arsenic surface which arsenic surface constitutes the cathode, whereby to overcome the destructive electrolysis and dbcomposition in the boiler, and to over-' come general corrosion and .localized pitting of the boiler structure, by the specific neutralizing action of the arsenic and by the the boiler as an electrolyte, a plurality of electrodes submerged in said electrolyte, and means for supplying current to said electrodes as anodes for converting the boiler into a cathode to receive a plat-in; of arsenic, which arsenic becomes the cathode when boiler 1s put 1n service.

In testimony whereof, I afiix my signa- 15 ture in the presence of two witnesses at 36 W. Randolph'St., Chicago, Illinois.

LEWIS O. GUNDERSON.

Witnesses:

DANIEL A. BRENNAN, E. H. RIEKEN.

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