US2289915A - Protective coated receptacle - Google Patents

Description

July 14, 1942. H. 1.. KOHLE R 2,289,915 PROTECTIVE COATED RECEPTACLE Filed Nov. 25, 1958 Fig.4

1 i INVENTOR 20 Henry 1.. Kali/gr ATTORNEY Patented July 14, 1942 PROTECTIVE COATED RECEPTACLE Henry L. Kohler, Kansas City, Mo., assignor to Andrew A. Kramer, Kansas City, Mo,

Application November 25, 1938, Serial No. 242,355

11 Claims.

My invention relates to receptacles, and more particularly to a protective coated receptacle.

It is a particular purpose of my invention to provide a receptacle that is made of sheet metal, or sections of sheet metal, that will resist certain types of corrosion encountered in the storage of certain liquids in such a receptacle as a sheet metal tank, for example. It has been previously customary to use galvanized metallic sheets for making sections of tanks that are intended to resist corrosion from undesirable ingredients in crude oil, water of certain types, and so on. The zinc coating of a galvanized metallic sheet is not particularly resistant, however, to corrosion, such as is encountered in the storageof certain oils in tanks, which oils contain sulphur compounds that act on the zinc coating to corrode the same. The same difficulty with galvanized sheets is experienced in connection with the storage of certain waters that contain undesirable ingredients that act on the zinc to corrode the same. I have found that by coating all of that part of the surface of the tank, or other receptacle, that is exposed to the action of sulphur compounds, and other similar compounds, that tend to corrode the zinc coating on a galvanized sheet, with an amalgam of mercury, this difficulty is largely, and sometimes entirely, overcome. Oil or water that so rapidly corrodes a zinc sheet that it is impractical to store such water or oil in the receptacle made up of galvanized sheets, or sections, can be stored in a receptacle made in accordance with my invention, as the receptacle will have such a greatly increased life that the use thereof is highly practical, instead of impractical, as is the case with a receptacle made of the usual galvanized sheets, if used for the storage of such corrosive liquids.

It is a particular purpose of my invention to also avoid certain dilficulties encountered in mak ing receptacles of galvanized metallic sheets that are flanged by bending the material of the sheet after galvanization thereof. A diificulty that has always existed in the utilization of galvanized metallic sheets, in making such flanged sections of a metallic receptacle, or tank, made up of galvanized metallic sheets, is that when such galvanized metallic sheets are bent the coating of galvanizing at a bend tends to crack and flake or peel off. In order to increase the life of galvanized metallic sheets in receptacles used for certain corrosive oils, or waters, or other liquids, it has been customary to place an extra heavy coating of galvanizing on the sheets. However, this merely adds to the difficulties resulting from flanging, or bending, these sheets, as the heavier coat of galvanizing will crack at the bend more readily than the lighter coats, and the tendency to flake or peel off at such a bend, due to such cracking, is more pronounced in a tank made up of sheets that have a heavy coat of galvanizing thereon than those that have a lighter coating of galvanizing thereon. As a result, although the she'etas a whole was provided with a heavy galvanizing coating over its entire surface before fabrication, the bending of the sheet to form the flange thereon, or other bend therein, damages the galvanizing coating on the sheet so seriously that it would render the coatingpartially inefiective, where such bends were made. As a result, the advantages of the heavy galvanizing coating on the sheet were largely lost, because the galvanizing coating was caused to be damaged, or ruptured, by the bending, and that portion so damaged, or ruptured, was hardly any better than an uncoated sheet, as far as oxidation, or other corrosion, was concerned.

It is accordingly an important purpose of my invention to provide means for protecting a tank made up of flanged galvanized sheets, at the bend, or bends, therein, so as to prevent any corrosion thereof at said bend, or bends, even though the galvanizing coating may have been ruptured in making the bend to form the flange, and to provide a protective coating at such bend, or bends, that will be even more resistant to corrosion, due to certain causes, than the galvanized sheet was before such bending thereof took place, and which will resist every kind of corrosion at least equally as well as the galvanized sheet did prior to such bending to form the flanges.

" It is an important purpose of my invention to provide a tank, or other receptacle, that is provided with a protective coating, which provides protection against certain types of corrosion over the entire area of the inner surface of the tank,

or receptacle, that is subjected to the corrosiveit phuric acid, Hydrogen sulphide does not affect it as readily as it does zinc, and other dilute acids do not have any decisive corrosive effect thereon. The amalgams of mercury take on the characteristics of mercury to the extent that these are also highly resistant to corrosion, particularly to corrosion due to acids, such as dilute sulphuric acid, and other acids, or compounds, that are encountered in the use of galvanized metallic sheets in making tanks, or other receptacles, that are to hold liquids, such as oils, or waters, that may contain sulphur compounds, or other compounds, that cause corrosion of the zinc on the ordinary metallic sheet.

It is also a purpose of my invention to provide a protective coating for a galvanzed sheet, particularly at a ruptured place in the zinc coating, by applying mercury, or an amalgan of mercury, thereto, so as to amalgamate the mercury with the ruptured zinc particles and with the zinc on the sheet to form an amalgam containing zinc and mercury, which will cover the ruptured place at the bend in the sheet at a flange, or similar place. An amalgam can be made of mercury with zinc, tin, lead, or any metal that freely dissolves in the mercury, and applied to the part to be protected, whether it be only at a place at or adjacent the rupture, at a bend, or a flanged portion, of the sheet, or over the entire inner surface of a tank, or similar receptacle, made up of galvanized sheet metal sections.

, While metallic mercury can be used, there is so much difliculty encountered in preventing loss of mercury, because of its extremely mobile character, that a putty-like, amalgam of mercury with any one of the above mentioned metals, preferably, either tin or lead, or lead and tin, is utilized to provide the amalgam coating referred to. Salts of mercury can also be used, but care must be taken that the amount of the salt utilized does not cause the zinc to all go into solution, as the action that takes place when salts of mercury are utilized, is thatthe mercury in the salt is replaced by the zinc that was on the sheet and the mercury deposits in the metallic form on the sheet and amalgamates with some of zinc on the sheet. Preferably, an amalgam of the consistency of putty, is rubbed on the metal over the entire surface where the same is to be protected by the amalgam coating, either at the ruptured place, or over the entire inner surface of the sheet, or section, as the case may be.

It is an important purpose of my invention to provide a tank, or receptacle, of the above mentioned character, which is made up of galvanized sheet metal sections, which are provided with a protective coating thereon, where it is desired to particularly protect the same against corrosion, that retains the characteristic spangled appearance of the galvanized metallic sheet that it has where only the zinc had been applied thereto in the usual manner, as in galvanizing the same. This can be accomplished by utilizing the paste-like amalgams, such as referred to above, for application to the zinc coating on the sheet to amalgamate therewith to form, for example, a zinc-tin-mercury amalgam, or zinc-lead-mercury amalgam, on the surface that is to be particularly protected, such as the inner surface of the tank, or receptacle. Thus the sheet metal, sections will have substantially the same appearance after being treated to. protect the same from corrosion as these had beforev such: corrosion protection was applied thereto, which is particularly desirable from a commercial standpoint.

Other objects and advantages of my invention will appear as the description of the drawing proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or described, except as defined in the claims.

In the drawing:

Fig. 1 is a vertical sectional view, partly in elevation and partly broken away, of a tank embodying my invention.

Fig. 2 is a fragmentary section on a very muchly enlarged scale, taken on the line 22 of Fig. 1.

Fig. 3 is a similar section, taken on the line 3-3 of Fig. 1.

Fig. 4 is a similar section, taken on the line 2-4 of Fi 1.

Fig. 5 is a fragmentary section, on a very muchly enlarged scale, through the flange on one of the side wall sections of my improved tank before the protective coating has been applied thereto, showing the rupture at the bend on the outer side of said bend where the flange is formed, and

Fig. 6 is a viewsimilar to Fig. 5, showing the flange, after the protective coating repairing the rupture in the zinc coating, has been applied thereto.

Referring in detail to the drawing, my improved tank is shown as comprising a bottom made up of the sections it), said sections being lapped and bolted together in a well known manner, a side wall made up of the sections H, which are flanged, as shown at I2, and which are lapped at their vertical joints, as shown at l3 in Fig. 1. The flange [2' at the top circumferential edge of the sections ll, forming the top ring of the side wall, are bent at a slight oblique angle to receive the inclined roof sheets, or sections, l4, which are supported at the center thereof by a central support l5 comprising a central column, or post, I6, which is mounted in any desired manner, as by means of the flange ll, secured by bolting to the bottom of the tank. The bottom sections, side wall sections and top wall sections, are all secured together and to the central support, by means of the bolts l8.

Preferably, if the entire inner surface of the tank is to be protected against corrosion, due to dilute sulphuric acid, hydrogen sulphide, or other similar compounds, that act on the zinc coating of a galvanized sheet to corrode the same, the bottom sections, or bottom forming sheets, are provided with an amalgam coating containing zinc and mercury over the entire inner surface thereof, which, of course, would be the upper surface of the bottom as, it is arranged in the tank. The amalgam coating is indicated in Fig. 2 by the numeral 20, and the ordinary zinc galvanizing coating on the outer or under surface of the bot tom is indicated, by the numeral [9. The side wall of the tank is similarly coated with an amalgam coating containing zinc and mercury on the inner face of the sections H, that is, that surface that faces the inside when the sections are in place in the side wall. of the tank, the amalgam coating being indicated by the numeral 20 in Fig. 3, and the zinc coating on the outer surface of the side wall sections II by the numeral IS. It is, of course, to be understood that if the entire inner surface of the tank is to be coated with the protecting material, the amalgam is provided on the surface of the entire section, continuing around the bend therein at the flange to the outer edge ofthe flange, or flanges, thererosion, because many of the corrosive elements only act on the zinc in a liquid state, or while in solution in a liquid, such as oil, or water, yet certain gaseous compounds containing sulphur will and do act undesirably on the galvanizing coating on the inner or under surface of the top wall of the tank under certain circumstances. In such a case it is desirable to provide the protective amalgam coating containing zinc and mercury over the entire inner surface of such deck sections, or roof sections. A fragment of such a sheet is illustrated in Fig. 4, in which a roof section I4 is shown that has a galvanizing coating I9 on the top, or outer surface, thereof, and the protective amalgam coating 20 on the bottom, or inner surface, thereof.

In Fig. a flanged side wall section II having a flange l2 thereon is shown on an enlarged scale. The zinc coating I9 is shown as being on both sides of the sheet and on the inner side of the bend at 2| the coating has not been damaged by bending the sheet to form the flange l2. On the outer side of the bend at 22 a rupture has developed, because of the bending of the sheet to form the right angular bend to provide the flange I2, the zinc coating [9 being cracked, or broken, at this point so that it does not serve to protect the iron or steel of the sheet, or section, ll.

While it is desirable to protect the entire inner surface of the tank, or receptacle, when certain particularly corrosive liquids, or certain liquids containing particularly corrosive ingredients, or compounds, are stored therein, it is desirable to prevent any possibility of corrosion, even from other less corrosive liquids, which do not have any undesirable effect on the ordinary heavy zinc galvanizing coating, at places where there are or may be ruptures at the bends of the sheets, due to forming the flanges I2 thereon. Such a tank would have the bottom sections it! thereof provided with the galvanizing coating IS on both sides thereof, as would also the side wall sections II and the top wall sections H, but the side wall sections would be provided with the amalgam coating containing zinc and mercury at and adjacent the bends therein formed to provide the flanges on the outer sides of the bends to close up the ruptures and provide a protective coating at the ruptures, which will be equally as protective and even more protective to the metal, such as the steel, or iron, of the side wall section II, than was the case prior to rupture thereof, due to the bending operation. To accomplish this, the amalgam coating is provided at 20 extending, preferably, from the outermost edge 23 of the flange around the outer side of the bend at 22 and for a substantial distance from said bend 22 along the inner surface of the sheet, such as to the point indicated by the numeral 24 in Fig. 6, the numeral 20 indicating theprotective amalgam coating in Fig. 6.

While metallic mercury, or a salt of mercury, can be applied to the surface of the side wall sections II at and adjacent the bends to provide the amalgam coating on the area above referred to, or to the entire inner surface of the bottom wall sections and side wall sections, and under certain circumstances, the top wall, or

deck sections, the preferred manner of providing the coating on the sheets is to utilize a pastelike amalgam of a metal readily amalgamating with mercury, and mercury, and applying this paste-like amalgam to the area of the sheet that is to be protected. This is, of course, done after all fabrication operations, such as bending, cutting and punching, have been performed on the sheet. After the sheet metal section of the bottom, side or top wall of the receptacle, or tank,

has been completely fabricated, it is cleaned at the places at which the protective coating is to be provided thereon, usually by means of dilute hydro-chloric acid, or a solution of tin chloride, or antimony chloride, or lead chloride, or zinc chloride, or cyanide of soda. The cleaning solution is applied with a brush, or swab, of some character, and the excess removed with a cloth, or other suitable means. A putty-like amalgam of mercury and a metal readily dissolving therein, or amalgamating therewith, is made up prior to cleaning the sheet metal sections of the receptacle, or is made up in quantity to be used whenever necessary. The amalgam has such proportions of the metal, or metals, that are amalgamated with the mercury, that a soft putty-like material of a consistenecy of thick cream, or paste, is produced. The proportions of mercury and other metals amalgamating therewith, that are used to produce this soft putty-like material, will vary with the metals used and with the atmospheric temperatures existing, in order that the soft creamy-like meta] will result, which can be easily applied to the sheet. In the winter time a lower temperature is encountered and a larger proportion of mer cury to the metal that is to be amalgamated therewith to make the putty-like material, is necessary.

I have found that when tin or lead, or lead and tin, are amalgamated with mercury, a particularly desirable coating is obtained, as the lead and the tin are much more resistant to the corrosion usually encountered in oils, and corrosive waters, than is the zinc, and thus the tin or lead will aid in the protective effect that is obtained by amalgamating the mercury with the zinc. I have found that 60% mercury and 40% tin by weight will produce an amalgam of the desired consistency in the summer time, and that in the winter time frequently it is necessary to make up an amalgam of one part by weight of tin to two parts by weight of mercury, and if exceedingly low temperatures are encountered, even one part by weight of tin to three parts by weight of mercury are desirable. If the mercury is heated when the tin is added thereto, as much as 55% tin can be included in the putty-like amalgam.

I have found that 65% mercury and 35% lead by weight will produce an amalgam of the desired consistency in the summer time, While in the winter time, when the temperatures are exceedingly low, it is frequently necessary'to utilize an amalgam for this purpose that is made up of one part by weight of lead, to three or four parts by weight of mercury. Substantially the same proportions are necessary where lead-tin solder is used, to produce a lead-tin-mercury amalgam, as when lead is used.

In making up the putty-like amalgam it is necessary that the lead or tin be in a finely divided form, the lead or tin being incorporated in the mercury by stirring the small particles thereof into the mercury. Preferably, lead-tin solder is similarly divided up into small particles when incorporated in the mercury to form the amalgam, although it is possible to dissolve, or amalgamate,

the solder in the mercury by heating the mercury above room temperature, so that the solder will approach its melting point when placed in the mercury, the solder then being capable of being incorporated in the amalgam by placing relatively larg pieces thereof in the heated mercury and stirring the same to dissolve the solder in the mercury.

The soft putty-like amalgam of tin and mercury, or lead and mercury, or lead, tin and mercury, produced as above described, is applied to i is a rupture or damaged area in the sheet, from which the zinc has been entirely, or substantially entirely, removed, the amalgam will adhere to the sheet at this ruptured area also. As soon as the amalgam contacts the zinc coating on the sheet it begins to act thereon to amalgamate the zinc coating with some of the mercury in the amalgam. Accordingly, in brushing the amalgam back and forth over the ruptured area, some of the zinc of the galvanizing coating will be caused to be spread over the ruptured area, and any loose particles of zinc will be dissolved in the amalgam, amalgamating with the mercury in such amalgam.

The action between the zinc and the tin-mercury amalgam, or lead-mercury amalgam, or the lead-tin-mercury amalgam, as the case may be, will continue until the amalgam has penetrated the entire zinc coating where applied thereto, down to at least the ferrous zinc alloy found at the surface of the steel, or iron, of the sheet. As the same amalgamates with the mercury, the resulting amalgam will gradually become stiffer and harder, as the greater the amount of other metal amalgamated with the mercury, the harder and stiffer the amalgam will become. As a result, the penetration of the zinc by the amalgam will eventually produce either a zinc-tin-mercury amalgam protective coating, or a zinc-lead-mercury amalgam protective coating, or a zinc-tinlead-mercury amalgam protective coating on the sheet over the entire surface to which the particular amalgam has been applied, which has lost the soft character of the amalgam that was brushed on the sheet, and will become as hard as the zinc coating originally on the sheet. It has been found that the use of an amalgam containing lead produces more rapid hardening of the amalgam coating on the sheet, than when a tin-mercury amalgam, for example, is used. After at least 24 hours the coating at the area to which the amalgam has been applied, will be hard enough that none of the same Will rub off, and the sheet, or section, can be handled without any damage to the coating. The sheet will, after the coating has become hard, have substantially the same appearance as it did before any amalgam was applied thereto, where these putty-like amalgams are used to produce such amalgam coating, but none of the coating can be rubbed off, even though it may be rubbed persistently for a considerable period of time. The amalgam coating will have the characteristic spangled appearance that the zinc coating originally on the sheet had. This indicates that the application of the putty-like amalgam to the sheet, while result- This rubbing, or

ing in the dissolving of the zinc on the sheet,.i1'l the mercury of the amalgam, does this in such a gradual manner that the. liquefaction of the zinc takes places at such a slow rate through the thickness of the zinc coating, that the structure thereof on the sheet is not altered, although the composition changes from substantially pure zinc to a zinc-tin mercury amalgam, a zinc-lead-mercury amalgam, or a zinc-lead-tin-mercury amalgam, as the amalgamating process proceeds through the coating. The sheet metal section will accordingly have substantially the same appearance two or three days after the amalgam wasapplied thereto as it had before any application of amalgam thereto, whether the amalgam be applied only at or adjacent the bend where the flanges were formed, or over the entire area of the surface of all of the sections of the tank, or receptacle.

When a putty-like amalgam containing 40% tin and 60 mercury by Weight is utilized for application to a galvanized sheet that has a coating thereon of zinc amounting to one ounce per square running foot, or one-half ounce per square running foot of surface on the sheet, the amalgam will contain approximately 65.3% zinc, 13.7% tin, and 20.5% mercury. When a puttylike amalgam containing 35% lead and 65% mercury by weight, is utilized for application to such a galvanized sheet, the amalgam will contain approximately 7 i% zinc, 10.2% lead, and 15.4% mercury. If a putty-dike amalgam containing 69% mercury and 40% by weight of a tin-lead solder, that is made up of 33%% lead and 66%% tin by Weight is utilized for application to the galvanized sheet, above referred to, the amalgam resulting will contain approximately 70.85% zinc, 7.77% tin, 3.88% lead and 17.5% mercury. With a heavier coating of zinc, the percentage of zinc will, of course, be higher, and the percentage of lead, or tin, or lead and tin, will be less in the case of an amalgam being used that contains a larger percentage of mercury. In all cases the amount of zinc in the amalgam coating resulting will be over 50% and the coating wiil retain the characteristics of a zinc coating to a certain extent, but will be modified in it characteristics considerably by the mercury contained therein, and to a lesser extent by the lead or tin, or tin and lead contained therein.

The tendency of sulphur compounds, when acting on the amalgam coating above referred to, is to cause the mercury in the amalgam to form a protective film on the surface that is exposed to the action of the dilute sulphuric acid, or hydrogen sulphide, or other sulphur compound, this causing some slight loss of some of the other metals from the coating, such as the zinc and the tin and to some extent the lead, but the mercury arresting this loss substantially immediately, due to its ilim forming action. As a result, a tank made up as described herein, having an amalgam coating of the character described herein, over the entire inner surface thereof, will, when utilized for storage of liquids containing sulphur compounds, or similar corrosive substances, have a life many times that of an ordinary galvanized tank, even though such tank is proved with a heavy galvanizing coating, and a tank that is made as illustrated in Figs. 5 and 6, and which has a heavy galvanizing coating treated at the outer sides of the bends in the sections thereof in the manner described in connection with Figs. 5 and 6, Will have no Weak spots in the protective coating thereof,

which might cause corrosion and damage to the sections of the tank where a galvanizing coating, if undamaged, would ordinarily protect the surface of the sections of the tank, so as to not be corroded.

Tanks that have flanged sections bolted together are particularly desirable, because of the fact that these have an inherent stiffness, which makes it possible to make a tank that is more nearly round and can be more easily assembled, than tanks that are not so made. By avoiding any possibility of a weak, damaged, or ruptured place in the protective coating of such a sheet metal section, due to the formation of flanges thereon, any objection that might have previously existed to tanks made up of flanged sections is overcome and the advantages of resisting wind pressure and keeping the tank in a truly round or cylindrical shape, that exists in tank made up of flanged sections, such as shown in Fig. 1,

can be obtained by making a tank of such flanged" sections, if coated in the manner herein described, without any disadvantages whatsoever resulting therefrom.

What I claim is:

l. A receptacle of the character described, comprising sheet metal sections having a zinc coating on the outer surface thereof and having a zinc-lead-mercury amalgam coating on the inner side thereof.

2. A receptacle of the character described, comprising outwardly flanged sheet metal sections having a Zinc coating on the outer surface thereof and having a zinc-lead-mercury amalgam coating at and adjacent the bends in said sections providing the flanges thereon on the surface thereof lying on the outer side of the bends.

3. A receptacle of the character described, comprising sheet metal sections having a zinc coating on the outer surface thereof and having a zinc-tin lead-mercury amalgam coating on the inner side thereof.

4. A receptacle of the character described, comprising outwardly flanged sheet metal sections having a zinc coating on the outer surface thereof and having a zinc-tin-lead mercury amalgam coating at and adjacent the bends in said sections providing the flanges thereon on the surface thereof lying on the outer side of the bends.

5. A receptacle of the character described having bottom, side and top walls, each of said walls having a zinc coating on the outer surface thereof and a coating of an amalgam of zinc, a metal of the lead-tin group readily amalgamating with mercury, and mercury on the inner surface thereof, said amalgam coating containing at least 50% zinc and at least 15% mercury by weight and covering the entire inner surface of all said walls.

6. A receptacle of the character described having bottom, side and top walls, each of said walls having a zinc coating on the outer surface thereof and a coating of an amalgam of zinc, a metal of the lead-tin group readily amalgamating with mercury, and mercury on the inner surface thereof, said amalgam coating containing from 65% to zinc and at least 15% mercury by weight and covering the entire inner surface of all said walls.

7. A receptacle of the character described having bottom, side and top walls, each of said walls having a zinc coating on the outer surface thereof and a zinc-tin-mercury amalgam coating on the inner surface thereof, said amalgam coating containing at least 50% zinc and at least 15% mercury by Weight and covering the entire inner surface of all said walls, there being from to 1% as much tin as mercury by weight in said amalgam coating.

8. A receptacle of the character described having bottom, side and top walls, each of said walls having a zinc coating on the outer surface thereof and a coating of an amalgam of zinc, a metal of the lead-tin group readily amalgamating with mercury, and mercury on the inner surface thereof, said amalgam coating containing at least 50% zinc and at least 15% mercury by weight and covering the entire inner surface of all said walls. and being of substantially the same composition from the sheet metal body of the wall to the exposed inner surface thereof.

9. A receptacle of the character described, comprising a plurality of outwardly flanged sheet metal sections having securing means extending through the flanges thereof to secure said sections together, each of said sections having a zinc coating on the outer surface thereof and a coating of an amalgam containing zinc and mercury on the inner surface thereof, said amalgam coating extending around the bends of said flanges on the outer side of each bend and beyond said bends a substantial distance along the inner face of each section and along the face of each flange directed toward the flange of the next section.

10. A receptacle of the character described, comprising a plurality of outwardly flanged sheet metal sections having securing means extending through the flanges thereof to secure said sections together, each of said sections having a zinc coating on the outer surface thereof and a coating of a zinc-tin-mercury amalgam on the inner surface thereof, said amalgam coating extending around the bends of said flanges on the outer side of each bend and beyond said bends a substantial distance along the inner face of each section and along the face of each flange directed toward the flange of the next section.

11. A receptacle of the character described h'aving bottom, side and top walls, each of said walls having a zinc coating on the outer surface thereof and a coating of an amalgam of zinc, a metal of the lead-tin group readily amalgamating with mercury, and mercury on the inner surface thereof, said amalgam coating containing from 65% to 75% zinc and at least 15% mercury by Weight and covering the entire inner surface of all said walls, said amalgam coating having the spangled appearance of a zinc coating.

HENRY L. KOHLER.

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