US1805215A - Means for coating metallic articles, particularly the interiors of water mains - Google Patents

Description

May 12, 1931. F. w. HAMMOND 1,305,215

MEANS FOR COATING METALLIC ARTICLES, PARTICULARLY THE INTERIORS OF WATER MAINS (IN SITU) Filed May 13, 1930 2 Sheets-Sheet 1 wfw F 05 emf I/K flaw/vamp May 12, 1931. w HAMMOND 1,805,215

MEANS FOR COATING METALLIC ARTICLES, PARTICULARLY THE INTERIORS OF WATER MAINs (IN SITU) V Filed May 15, 1930 2' Sheets-Sheet 2 Patented May 12, 1931 tain a percentage I prevent such re-growth UNITED STATES PATENT OFFICE FREDERICK witnim-mmonmor c mrs'row, ENGLAND means roa comma METALLIC narrows; PARTICULARLY rim INTERIORS or warm MAINS n SITU) I Application filed May 13, 1930, Serial No. 452,118, and in Great Britain March 5, 1930.

This invention provides improved means for depositing a protective coating on metallic articles, particularly the interior surfaces of water mains (in situ) including a colloidal solution or emulsion of fiuxed bitumen and other ingredients in an aqueous medium from which the said coating is deposited by electrolysis between an anode consisting of the positively charged metallic article to be coated and a negatively charged cathode which is movable opposite to and along the surfaces of said metallic articles,.

and a source of direct electric current.

Ithas been found in practice that after scraping and clearing away the deposits of Organic and inorganic grounds in water mains, fresh deposits set up very quickly, due to inferior pipes or pipes with inferior bituminous coating and to the action of the water conveyed, with the result that ob ectionable discoloured water is supplied and an important object of this invention is' to of deposits and discolouration of the water.

The present invention therefore provides a protective solution or emulsion containing fluxed bitumen and other ingredients and apparatus whereby the said solution or emulsion is de osited by electrolysis on the surfaces of t e metallic articles so as to leave a smooth and coherent continuous coating,

impervious to water, of colloidal particles of bitumen with other protective ingredients.

The electrolytic coating is deposited from a colloidal solution or emulsion which ncludes pure petroleumbitumen fiuxed with asphalt oil and/or paraffin wax, with or without a percentage of saponaceous mate rial plus a protective adhesive colloid such as casein, gum or strach as emulgent.

In certain cases the electrolytic solution may'include pure petroleum bitumen fluxed with asphalt oil and have a percentage of casein, gum or strach, or in addition to the foregoing ingredients the solution may conof saponaceous material.

In other cases the electrolyte may include pure petrolum bitumen fluxed with asphalt oil and parafiin wax of either one of these fluxes and have a percentage of casein, gum

or strach as adhesive and emulgent, or in ad-- The fiuxed bitumen content of the electrolytic solution is approximately 25% of the total weight of the. solution, and of the other ingredients when included, from 0.25% to 0.5% of alkali, from 0.25% to 0.5% of fatty acid, from 0.05% to 0.1% of casein, gum or strach.

The electrolyte is applied by partial. or total immersion or by spraying, to the article to be coated which is connected as one of the electrodes to one pole of a dynamo while the other electrode, which is of shape or section conforming suitably to that of the articles to be coated, contains or is immersed in the electrolyte and is connected to the other pole of the dynamo;

The article to be coated is connected to the positive pole of the dynamo as anode, and the shaped electrode to the negative pole as cathode, the latter, when water pipes are to be coated, being a metallic tube or cylinder -mounted on a carriage of insulating material-and caused to travel through the water pipes which are first filled with the electrolyte, or the latter may alternately be sprayed in jets from the negatively charged cathode as it travels through the water pipes or a cathode sealed at each end by hydraulic washers and carrying its own supply of electrolyte fed by a hosepipe as it travels or is drawn through the water pipes, ma be used.

In order that the invention may e clearly understood, there will now be described with the aid of the accompanying drawings, various modifications of the apparatus suitable for metal articles of different kinds and sizes.

In the drawin s:

Figure 1 is a iagram showing the-appli-v cation of the process to metal articles generally.

Figures 2 and 3.are longitudnal and cross sections respectively of a water pipe of small diameter, to be filled with the electrolyte and with suitable apparatus therein.

Figures 4 and-5 are longitudinal and cross sections respectively of awater which are of moderate size and compact shape, a suitable vessel 1 contains the electrolytic solution, the article 2 which is to be coated and which is connected to the positive pole 3 of the electric supply, and also the negatively charged cathode 4 which is connected to the negative pole 5. The cathode 4 may be moved opposite to and along'the surfaces of the article 2 when the latter is of sufficient area or extent torequire such movement. A voltmeter 6 and ammeter 7 are provided in the circuit in order that the electric supply may be regulated through the electrolyte. v

For water pipes of small or moderate diameter, as shown in Figures 2 and 3, the pipe 8. is to be filled with the electrolyte from a tank or by other suitable means, and into the pipe 8 there is introduced acylinder 9 preferably of copper as the negatively charged cathode which is arranged to 'be drawn through the pipe 8 by a cord or wire rope fixed to an msulating bridge-piece 10.. A carriage 11 of insulating material, such as hardwood, supports the cylinder 9 and is fitted with rubber discs or rings 12 to centre the cylinder 9 in the pipe 8 and to facilitate its passage therethrough. The rings 12 are perforated or have scalloped edges to allow free passage of the cathode 9 through the electrolyte, but the rings are staggered so that the perforations are not in direct alignment to prevent the pipe 8 being coated imperfectly ahead of the cathode 9. Four of the rings 12 are generally employed but these may be added to with advantage for larger ipes.

' Waterproof cable '13 is connected to a terminal 14 on the front end of the carriage 11 and a central conductor 15 connects between the terminal 14 and the cylinder 9 via a flexible lead 16. There is a wooden boss 17 at the rear .of the cylinder 9 to prevent it from touching the walls of the 'pipe 8 and so makr ing a short-circuit for the current.

Referring nowto Figures 4 and 5, the cathode 18 is for use with pipes which are too large to be easily filled with electrolyte and it has at the ends carriages l9 and 20 of insulating material, such as hardwood, which are fitted with rubber discs or rings 21 and leather hydraulic washers 22 which centre and insulate the cathode 18 in. the water which is carried between the cathode 18 the water pipe 23;

The electrolyte is fed through a hosepipe 24 to a tube 25 running through the front and carriage 19 and emerging through the surface of the cathode'cylinder-18, any surplus being allowed to escape past the rear rubber ring 21, and hydraulic washer 22. This is necessary to maintain the concentration of bitumen required in the electrolyte in use between the cathode cylinder 18 and the water pipe 23.

The numbers of rubber rings and hydraulic washers used depend on the size of the water pipe to be coated, being one or more of each per carriage.

a Means of supplying electric current and means of hauling through the Water pipe are provided as hereinbefore described and the cathodes are in all cases to be drawn through their respective pipes at such a speed as "will ensure correct deposition-of the bitumen particles.

Referring now to Figures 6 and 7, which illustrate an apparatus for coating pipes large enough to admit of the ingress of a man, the cathode is a brass plate 26 curved to the shape of the inner surface ofthe water pipe 27 and is held in a box 28 of insulating'material, such as hardwood, similarly curved to the pipe 27; the cathode plate 26 is insulated from the pipe 27 by a flexible rubber edging 29 which also serves as a seal for the electrolyte between the pipe 27 and the oathode plate 26.

A supply tube 30 isarticulated to the box 28 and conveys a supply of electrolyte from a suitable reservoir to thebox 28 and to the I space between the cathode plate 26 and the inner surface of the water pipe 27 via a hose pipe 31 and a short tube 32 emerging through the surface of the cathode plate 26; a valve 33 is provided at the top end of the tube 30 to control the flow of the electrolyte. The tube 30 is universally jointed by being held by a ball 34 between two cups 35iand 36 midway between two wood- wheeled trolleys 37 and 38 forming a travelling carriage and being held against the top and bottom of the pipe 27 by two telescopic screwed struts 39 and 40 capable of being extended or contracted by twqhand nuts 41 and 42, enabling the apparatus to be adjusted to the diameter of the pipe. y

Electric currbnt is provided and is supplied to the cathodeplate 26 by cable 43 connected to said plate 26 through box'28 and is controlled by and switch 45. 3

, A third telescopic screwed strut 46 behind- 27 and controlled by 'the hand nut 47 and fitted with a friction pad 48, enables the cathode plate and box 28 to be firmly held against cany' desired portion of the interior surface the ammeter 44 the waterproof of the water pipe 27, the ball 34 and cups 335 and 36 controlling radialmovement and the trolleys 37 and 38 controlling longitudinal movement in the pipe 27.

The pipe 27 can be coated at any desired part by straining the box 28 to the interior surface of the pipe 27, flooding the space between the cathode plate 26 and the pipe 27 and switching on the electric current for such a period of time as will ensure correct deposition of the bitumen particles.

The electric supply may be from a portable dynamo or from public supply mains giving direct current at about 100 to 110 volts whilst the current starts at about 0.16 amperes per square inch of surface to be coated and falls to a lower figure as the surface becomes coated.

I claim 1. Improved means for depositing a pro tective coating on metallicarticles, including a colloidal solution or emulsion or fiuxed bitumen and other ingredients in an aqueous medium from which said coating is deposited by electrolysis, an anode consisting of the positively charged water pipe to be coated, a

' cathode consisting of a negatively charged tective coating on metallic articles, including a colloidal solution or emulsion or fluxed bitumen and other ingredients in an aqueous medium from which said coating is deposited by electrolysis, an anode consisting of the positively charged water pipe to be coated, a cathode consisting of a negatively charged copper cylinder having at the ends travelling carriages of insulating material fitted with rubber discs or rings and leather washers, a supply. of electrolyte sealed between said rings and washers, a hosepipe feedin said electrolyte to a tube running through the front carriage and emerging through the surface of the cathode cylinder, a waterproof cable connected to a terminal on front carria e, a conductor and flexible lead between sai terminal and cathode cylinder, and a source of direct electric current.

3. Improved means for depositing'a prote'ctive coating on metallic articles, including a colloidalsolution or emulsion of fiuxed bitumen and other ingredients in an aqueous medium from which said coating is deposited by electrolysis, an anode consisting of the positively charged water pipe to be coated, a cathode consisting of a negatively charged metal plate curved to the inner surface of said water pipe, a box of insulating material holding said cathode plate and similarly curved, flexible rubber edging between said cathode plate'and water pipe, a supply tube articulated to said box conveying a supply of electrolyte from a reservoir to the space between said cathode plate and the inner surface of the water pipe via a hosepipe and a tube emerging through the surface of the cathode plate-and universally jointed by a ball and two cups between two trolleys, a travelling carriage formed of said trolleys which have wood wheels held against the top and bottom of the water pipe by two telescopic screwed struts on either side of said ball and cups and capable of being extended or contracted by two hand nuts to suit the diameter of the water pipe, a third telescopic screwed strut between the top of said supply tube and the water pipe controlled by hand nut and fitted with a friction pad to enable the cathode box and plate to be held against any portion of the water pipe by said ball and cups controlling radial movement and said trolleys controlling longitudinal movement, a waterproof cable connected to the cathode plate and a source of direct electric current.'

In testimony whereof I have aflixed my signature heretothis 23rd day of April 1930,

FREDERICK WILLIAM HAMMOND.

Images