US2370288A - Electrolytic protection of metal surfaces - Google Patents

Description

Feb. 27, 1945'. BR'OL'INSON 2,370,288

ELECTROLYTIC PROTECTION OF METAL SURFACES Filed Aug. 1, 1940 4 s Sheets-Sheet 1 INVENTOR- figg/ ti Brlz'nsan ATTORNEY Feb. 27, 1945.- B, G. BROLINSON ELECTROLYTjEC PROTECTION OF METAL SURFACES Filed Aug. 1, 1940 3 Sheets-Sheet 2 Feb. 27, 1945'. BRQLJNSON 2,370,288

ELECTROLYTIC PROTECTION OF-METAL SURFACES Filed Aug. 1, 1940 3 Sheets-Shet s -INVENTC )R V fzBruimsw;

Patented Feb. 27, 1945 ELECTROLYTIC PROTECTION OF METAL SURFACES Bengt G. Brolinson, New York, N. Y. Application August 1, 1940, Serial No. 349,124 1 Claim. (Cl. 204-196) This invention relates to the electrolytic protection of metals and more particularly to a system and apparatus for the electrolytic protection of containers, such as heat exchangers, conproposed to insert an anode in the liquid withinv the container and to connect the surfaces to be protected as the cathode to a source of curret. In certain instances, however, it is inconvenient or impracticable to insert anodes in the containers themselves. Such is the case in certain types of heat exchangers or condensers wherein the space is not sufiicient to receive the necessary anode surfaces. Furthermore, the cost of inserting anodes in a plurality of containers may be prohibitive.

In order to effect the necessary protection in cases of this kind it has been proposed to provide a separate anode chamber which is connected in the fluid circuit so that fluid passes through the anode chamber on its way to or from the container. The present invention relates particularly to this type of equipment and has for an object to provide a system of novel and improved construction, which is simple and convenient to install and which is eflicient in ope,

eration.

Another object is to provide an anode cham- Another object is to provide an anode chamber having novel and improved details of construction and features of operation.

Another object is to provide a novel and improved anode support.

Still another object is to provide a novel and improved means for supplying current to an anode in an elongated anode chamber.

A further object is to provide an anode chamber which is so constructed and arranged that the sediment or accumulations therein, may be periodically removed so as to prevent clogging of the chamber or interruption of the operation of the system.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

Although the novel features which are believed to be characteristic of. this invention are pointed out more particularly in the claim appended hereto, the invention itself may be betterunderstood by referring to the following description, taken in connection with the accompanying drawings in which the specific embodiment thereof has been set forth with illustration.

In the drawings: a

Fig, 1 is a top plan view of a bank of condensers having an. anode chamber embodying the present invention associated therewith;

Fig.2 is a side elevation thereof;

Fig. 3 is the vertical longitudinal section of the anode chamber taken along the line 3-3 of Fig. 2;

Fig. 4 is an enlarged detailed view of a portion of the anode chamber showing the anode support and the lead-in means for connecting the anode to an external circuit;

Fig. 5 is a transverse section taken on the line 5-5 of Fig. 4;

Fig. 6 is a side elevation, partly in section,-of an anode chamber containing a solid anode;

Fig. '7 is an enlarged section taken on the line l-! of Fig. 6 showing the construction of the current lead-in means;

Fig. 8 is a transverse section taken on the line 8-8 of Fig. 6 showing the anode support; and

Fig. 9 is a side elevation showing a bank of condensers with intermediate electrode chambers arranged for the serial flow of the fluid therein.

Referring to the drawings more in detail the invention is applied to a bank of containers, shown for convenience as condensers H), which are connected by individual inlet pipes l2 having control valves l3 to an inlet header II to receive therefrom the fluid, which in the case of condensers may constitute cooling water. It is to beunderstood that the condensers are also connected to a suitable outlet header, not shown.

The water is supplied from a main id to the inlet header l-I through a valve I 5. An anode chamber I6 is positioned parallel to the header H and is connected at opposite ends to the ends of the header by elbows l1 and I8 controlled by valves I9 and 20 respectively, the arrangement being such that with the valve 15 closed and the,

valves l9 and 20 open the water is supplied from the main 14 through the anodechamber l6 and thence to the header II and the condensers 10. With the valves l9 and 20 closed and with the valve l5 open, water is supplied from the. main I4 directly to the header H and thence to the condensers ID, the anode chamber l5 being then cut out of service and rendered inactive. It is to be understood that the condensers It! may be of the tube and shell type or of any other standard construction having metal parts which are subject to corrosion, scaling and fouling.

The anode chamber it, as shown more in detail in Figs. 3 and 4, comprises a tube 2i having a cross section substantially greater'than that of'the main M and the header ii. The elbows l1 and it may be connected to the opposite ends of the tube ill by means of flanges 23 and Ed. The elbow ill may be provided with a drain-pipe 25 having a valve 25 therein which, when open, permits the sediment or other materials in the pipe 2! to be removed.

The anode chamber contains an anode which is shown as an anode tube 28, which may be closed I if desired, mounted concentric with the tube 2i and insulated therefrom, The anode tube 218 may be supported by spaced pairs of legs shown as insulators 3b (Figs. 3, 4 and 5) which may be attached to the anode tube by suitable means,

shown as bolts iii. The outer surface of the anode tube 28 may be recessed to receive the insulators The insulators may be provided with caps 35 which may be formed with spherical tion only of the periphery of the tube so that I the anode tube 28 may be inserted with the legs 30 out of alignment with the blocks iii. After insertion the tube 28 may be rotated to bring the legs 29 into locking engagement with said blocks 4! for positioning and securing the anode as shown.

For making electrical connection to the anode tube 28 an ear may be secured thereto by suitable means such as by welding. A flexible connecting cable 46 maybe secured to the ear 45 by a bolt 41. v

The tube Zl-may-be provided with an opening 50 of suflicient size to afford access to the interior of the tube. The opening 50 may be closed by a cover plate 5| which may be secured Suitable gaskets and Gil by bolts 52 and may be provided with a sealing asket 53. The cover plate 5| carries a' lead-in assembly comprising a metallic sleeve 55 passing Suitable insulation 63 such as mica may be provided around the rod 62 to insulate the same from the sleeve 55. The assembly may be secured by means of lock nuts 64. An insulating gasket may be inserted over the sleeve 55 toinsulate the lock nuts 64 and the rod 62 therefrom.

The flexible connecting cable-46 may be provided with a flat connector 10 secured by means of a nut 68, to a threaded shank 59 formed on the block 6|. The exposed parts of the cable 46, the block BI and the ear 45 may be wrapped with insulation so as to completely seal the conducting parts from contact with the water in the tube 2|.

,legs 29 to permit inspection or adjustment thereof if desired, without dismantling the entire apparatus. The holes id may be closed by covers l6 secured by bolts ii.

For flushing out the anode chamber iii and removing deposits from the anode a set of nozzles $30, controlled by individual valves 82, is provided. In the embodiment shown these nozzles 85 are arranged in groups .of three peripherally spaced about the tube 2i near the ends of the anode tube 28 and directed towards the center of said tube. The aligned nozzles sit at the two ends of the tube 211 may be connected to pipes Si which are in turn connected to pipes 83 which are connected to a high pressure header til controlled by a valve 85 so that water under pressure may be supplied to said nozzles when desired. The nozzles must be arranged to provide a maximum clearance from the anode and may, if desired. be mounted in chambers raised above the surface of the tubes 25 similar to the chamber formed by the T i i id to be described, or the nozzles may be made of non-metallic material.

In the operation of this device the valve 5 5, Fig. l, is normally closed, and the water is supplied to the condenser iii through the anodechamber i t. It is to be noted that the condensers are connected tothe header ill in parallel and that the anode chamber i6 is connected in series with the bank of condensers. Suitable electrical connections are made to the surfaces to be protected and to the'rod 62 supplying current to the anode 28, so that the anode is made positive and the surfaces to be protected are made negative. The anode itself, however, corrodes and must be renewed or replaced periodically.

It has been found that after the system has been operated fora substantial length of time the anode chamber l6 becomes clogged due to the particles deposited from the anode and from the water itself and due to the scale which is removed from the anode. cally cut out of service for cleaning by opening the valve I5 and closing the valves i9 and 20. The chamber may then be flushed out by opening the valves 85 and 82 and supplying water to the nozzles 80. The material thus removed from the anode falls to the bottom of the anode chamber and may be flushed out of the drain pipe 25. If sufficient water is not received from the sprays 80 for this purpose the valve 20 may be opened to supply water to the chamber to flush out the accumulated material; The system may also be reserve-flushed by opening the valve i9 and closing the valve 20 to supply water through the elbow I! to the anode chamber.

When the anode 28 is to be removed the cover 5| may be removed to afford access to the cable 46 which may then be disconnected. The elbow l1 may then be removed and the anode may be withdrawn axially. It is to be noted, however, that the anode must first be rotated to release the supporting legs 29 from the blocks 4 l The cove: plates 16 may be removed for purpose of inspection or repair of the blocks 4|. The flushing out of the anode chamber and the inspection provided for by the various inspection ports permits the anode to be maintained in continuous service without dismantling except when it is necessary to remove and renew the same.

In certain instances it may be desirable to use a solid .anode such as a solid carbon or graphite rod. This embodiment of the invention is shown The chamber may be periodiin Figs. 6, '7 and 8 wherein the anode chamber I8 is similar to that above described. An anode rod 90 is provided, however, which in this embodiment is supported by legs 9| of suitable insulating material having secured therein, threaded studs 92 which are also secured in suitable tapped holes 93 in the anode rod 90. Suitable recesses 94 are provided in the anode rod to receive the ends of the legs 9|. The legs 9I are provided with caps 95, similar to the caps 35 above described.

In this embodiment the lead-in means differs from that shown in Figs. 1 to 5. As shown in detail in Fig. 7 the lead-in means comprises an insert 96 of impervious material such as treated graphite which may be threaded into a tapped recess in the side of the anode rod 90. A washer 91 may be positioned beneath the insert 96 to facilitate assembly and removal thereof. A terminal stud 98 is threaded into the insert 96 and an insulating sleeve 99 is threaded over the stud 98. The end of an insulated, flexible conductor I is inserted in a recess in the pin 98 and may be secured by a set screw IOI.

In order to make a water-tight seal so as to prevent moisture from entering beneath the ends of the insulation of the conductor I00 a packing box is formed by the insulating sleeve 99 which is closed by means of a non-metallic gland I02, threaded in said sleeve. The sleeve 99 may be seated on a sealing gasket I03.

The other end of the conductor I00 is connected to a rigid lead-in comprising a metal sleeve I I0 which passes through a cover II I mounted on a T Illa and secured by bolts lb. The T Illa provides clearance to obtain the length of insulator surface required to prevent surface creepage. The sleeve IIO may be secured in the cover III by nuts II2 and H3. "A gasket H4 and a washer II5 may be provided to eflect a watertight seal. An insulating sleeve IIB extendsinwardly from the sleeve II 0 and is securedby a current conducting rod I H which extends through the sleeve H0 and HE. A coating of insulating material II8, such as mica, surrounds the rod II1 to insulate the same from the sleeve H0. The sleeve H6 is clamped between a threaded head I24 and the sleeve I I0 by means of a nut I threaded on the rod I I1. Sealing gaskets I2I and I22 may be inserted over the ends of the sleeve I I6 and an insulating washer I23 may be disposed between the sleeve III] and the nut A terminal stud I I9 may be threaded onto the end of the rod I IL The end of the conductor I00 is secured in the terminal stud I I9 by means of a set screw- I26. A packing box is formed by an insulating sleeve I27 which is threaded onto the stud IIS, and a non-metallic gland I28. An insulating and sealing gasket I25 may be inserted between the head I24 and the sleeve I21. All electrical conducting members are thus sealed from contact with the water within the tube 2 I. The flexibility of the conductor I00 permits expansion of the parts due to temperature changes without damaging the equipment.

The embodiment shown in Figs. 6, '7 and 8 provides for the use of a solid anode rod. This may be desirable in the case of graphite or carbon rods, which have the property of protecting the oathodic surfaces without discoloring the liquid or introducing any metal ions therein.

In the embodiment shown in Fig. 9 a plurality of containers I30 are connected for the serial flow of water therethrough and a plurality of anode chambers I3I are arranged intermediate .ers and anode chambers.

In this system the anode chambers are positioned adjacent the inlet to each container so as to obtain the most eilicient action. The anode chambers are shown as graduated in size according to the temperature of the fluid in the various containers so as to take advantageof the increased conductivity of the hotter fluid, by reason of which less anode surface may be required. It is to be understood that the anode chambers I 3| are similar in construction to the anode chambers I6 above mentioned and may be bypassed when desired, consequently the details thereof have not been repeated.

In the system shown in Fig. l a single anode chamber is used to protect the plurality of condensers. In the system shown in Fig. 9, a plurality of anode chambers are used, one for each condenser or other element to be protected. The particular system used will depend upon the requirements of each individual case and may differ according to the metals present, the nature and content of the cooling fluid and the conditions of operation.

Since the anode chamber is filled with Water or other conducting fluid, it is essential to completely insulate all conducting members. vIt is also necessary to provide suificient flexibility to permit relative movement between the anode and the anode chamber due to expansion or contraction of the parts. In the embodiment of Figs. 1 to 5 this is accomplished by connecting a flex-- ible cable between the anode and an insulated lead-in which passes through the wall of the anode chamber. In the embodiment shown in Fig. 8, connection is made by means of a flexible insulated conductor. The joints between the conductor and the two terminal studs 98 and. i I9, however, are completely insulated and sealed by the stuffing boxes so as to prevent water from creeping inside the insulating covering. This construction prevents the conducting members from corroding due to contact with the water.

It is to be noted that the lead-in of Fig; 4 may be completely assembled and tested in the factory. This eliminates the necessity for assembling' and testing the conductors in the field. Furthermore, the cable 46 may be disconnected by the removal of the nut 68 without disassembling thelead-in itself. This is an important feature from a commercial standpoint inasmuch as it is more difiicult to obtain a permanent water-tight assembly in field than in a factory where there are proper facilities for assembling and testing.

The invention has been described as applied and modifications may be made therein as will be readily apparent to a person skilled in the art. The invention is only to be limited in accordance with the following claim.

What is claimed is:

A device for the electrolytic protection of metal surfaces in a container, comprising an anode chamber, an anode in said chamber, and lead-in means extending through said wall to make an electrical connection with said anode, said lead-in means comprising a metallic sleeve extending through said wall and secured thereto, an insulating sleeve extending inwardly from said first sleeve, a lead-in rod extending through said sleeves, insulating means surrounding said )15 lead-in rod to insulate the same from said metallic sleeve, a terminal block carried by said lead-in rod, means on said rod to clamp said sleeves against said block, a terminal block mounted in said anode, said terminal blocks having bores to receive the ends of a connecting cable, a flexible cable connected to both of said terminal blocks, said cable having an insulated covering, the ends of which are inserted in said it) bores and stufiing boxes associated with the bores of each of said terminal blocks to seal the ends of said insulation from the surrounding medium and prevent contact thereof with said cable.

BENGT G. BROMNSON.

Images