US1866757A - Packing and composition - Google Patents

Description

July 12, 1932. F, E, DE VRlES 1,866,757

PACKING AND COMPOSITION Filed Aug. 29, 1929 Patented July 12, 1932 UNTTED STATESN PATENT OFFICE FENNO E. DE VRIES, F EVANSTON, ILLINOIS, ASSIGNOR TO CRANE PACKING COM- IANY, A CORPORATION OF ILLINOIS :PACKING AND COMPOSITION Application filed August 29, 1929. Serial No. 389,155.

My invention relates to new compositions and improvements in packing embodying suchfcompositions, more particularly metallic packing used in condensers, evaporators and the like, Where the packing may be subjected to the action of liquids containing corrosive materials such as acid.

An object of the invention is to provide an improved packing whereby the packing may be effective for long periods of time, even though subjected to fairly high or variable temperatures or to liquids containing corrosive substances or to both, as in the case of a steam surface condenser for example.

Still another object of the invention is to improve the packing of the Payne Patent No. 1,714,725, so as to increase the resistance to corrosion.

A further object is improvement in the i u above mentioned patented packing by Which the corrosion resistance is increased and the packing made electrically conductive.

A further and important object of the invention is the manufacture of an electrically conductive composition, which may be used to coat and protect metallic packing.

Various other objects and advantages of the invention Will become apparent as the description and explanation of the invention proceeds. Y

In the Walton Patent 1,543,968 there is described a metallic packing which is particularly effective in some uses because it is electrically conductive. In the Payne Patent 1,714,725a metallic foil packing is described which is coated with an insulating and protective synthetic resin, particularly a flexible phenol condensation product. In my copending application Serial No. 389,156, filed August Q9, 1929, there is described another packing using as a base a cellulose derivative, such as nitrocellulose, rather than resin, as a protective agent on the foil. In putting suoli coatings on the metal foil which forms the packing the packing becomes eHectively insulated, and the electrically conductive properties of bare foilpacking are lost.

The present invention aims to improve the resistance to corrosion of such coated packings by incorporating certain fillers into the coating. Inert iillers or pigments may be employed, yet the invention is not limited to them. Metallic or other electrically conductive particles may be incorporated into the coatings, giving electrically conductive properties. Certain meta-ls may remain inert under the conditions of exposure, and the same r other metals may yield to corrosion forming oxides or other compounds Which act like pigments and provide additional resistance or protection against further corrosion. Graphite, lamp-black or other forms-of carbon are particularly desirable, especially graphite, because of its high degree of inertness and of its electrical conductivity.

The packing which is contemplated in this invention comprises metal foil, usually in strips, which is crimped, or is deformed in a systematic Way, and then compressed in a systematic Way into a solid object of desiredv shape or size. The surface of the foil, prior to compression and preferably prior to deforming or crimping, is coated With a flexible protective layer, such as the resin or cellulose derivatives referred to. 'Ihe coatings employed in this invention contain solid ingredients as above mentioned toimpart greater resistance to corrosion With or Without imparting electrical conductivity to the coating.

I have discovered that the resistance of such coatings is increased when ordinary paint pigments, metal powders, carbon, metal oxides and other solid ingredients are incorporated into the coatings. The use of graphite in particular Vis highly effective in this direction, and in spite of the fact that the coating substance is ordinarily an electrical insulator, I have discovered that graphite and metals in comminuted form in the coatings impart to it an appreciable electrical conductivity, so that the packing made with such compositions is also electrically conductive.v

In order to illustrate the invention I show `in the accompanying drawing several illus- Hmove Yther surplus coating. passes throughan oven 17, which inthe form shown comprises :a baking chamber'lined -with vrefractory `material 18 and fhaving aligned openings 19at opposite ends thereof Y"through which 'the coated foil stri-p enters and Aleaves the oven.

acentY tubesheet showinga typical packing installation; and l Fig. is a cross-sectional, enlarged view of coated foil with filler takenon thefline 5-5 of Fig. 1, prior to crimping or deforming into a packing.

Referring to Fig. 1, one or more spools or reels of metal foil-10 are shown rotatably vmounted on a suitable support 11. vThe metal foilmay be lead'foil, Babbitt foil, or copper or aluminum,an'd in some cases coated with tin iny advance. Each strip of foil is'fed'from the supply reel through a receptacle l2 con- `taining a bath or 1liquid 13, such for example as the yreactive filex'ible l'bakelite varnish,

known commerciallvas BV 1413,'made under the" Byck PatentNo. 1,590,079, or other suit- \able=coatinghaving the desired characteristic properties, and` such as the cellulose de'rivative 'described' in -my Vcopending application 'Serial-No."389,156, lile'd August 129, 1929.

Thest'rip passes under la suitable roller '14 in the fbathand" then overa -second roller l5 and thenV between wiping felts 16 to re- Said strip then TF or Ybaking thel phenol-condensation product-vas described inPatentNo. 1,714,725, the 'baking ,l chamber, fis heated 'from "below by a Asuitable :fuel such asgasburners`20 and-a suitable vent 21 may be provided' above the oven.

'.'Iheffoil on leaving the oven-or'drier passes vthrougha guide22-and is supported by said guident oneend and by. the roller at the other end, both outside of theoven; :being unsupported xwithin the f oven. vThe temperaturegof` the oven andy the-speedsat whichy the f fo1l-is`passed through itmay vary under dif- .ferent conditions, dependingon the character ofthe coating and the Vparticular.type of service forwhich. thepacking vis intended.

For a condenser packingand with a .particu- 'lar'Bakelite varnishXV 1410, thinned with a solvent of benzol and 50% alcohol,-a temperature of .about 500 F. is very satisfactory in conjunction with a speed'of about "3 feet per minutefor the `foil. `For a4 nitroce'lhiloselacquer less heat is `required to evaporate the volatile solvents in-the'lac- Yquer.

After passing -beyondthe guide 22,'.the

1,see,757

foil with the protective coating baked on it is wound on a suitable reel 23 driven by a gear and pinion 24: and 25, the latter being rotated by any suitable source of power such as a belt 26 ruiming over a pulley on a shaft .27, the latter being driven by a belt 28 from amotor 29. The shaft 27 extends across the machine and operates a plurality of reels 23, whatever number may be desired, and the oven of course has a corresponding series of aligned openings 19-19 therein through Whichstrips of foil may be fed from the spools 10. In other words a number of ,lengths of foilmay be coated and baked simultaneously.

As the foilleaves the guide 22 and is Wound on the-spool 23, it is pressed down against thefrlatter by asrrotatable wheel 30 carried by a pivotedarm 31. ySaid wheel is of substantial Weight and rolls the foil down in smooth layers.

These finished rolls are thereafter un- Wound as the foil is being fed into the machine'for forming the packing, in case it is so used. It is therefore necessary that the reel offoil be unwound without sticking or tearingand the process and apparatus described are so regulated and designed as to obviate this difficulty.

'After the metal foil is coated, it may be Wound ona suitable mandrel to form a helical ring of predetermined diameter,'width and thickness. The ring 32 thus formed is thereafter pressed in la` vdie 33 as shown in Fig. 2, during which operation the substantially concentric layers of' thin sheet metal fold themselves back and forth to form, in' cross section, wavy lines or interfitting accor'dion pleated layers, the four outer sur- 'faces of the ring, however, being smoothand compact. The finished ring, if subjected to side compression, i. e. inl a direction parallel to `its central axis, tends to expand radially inward and outward. There such a ring is used for packing the ends of condenser tubesl as` in Fig. 4 for example, one or more of said rings are slipped over the end of the condenser tube 34 and caulked'by special .tools andmay thereafter ybe further coinpressedby arferrule 35 of the usual form, if desired, although the ferrule may be dispensed With. Additional.intervening fibre washers 36.1nay be employed as Vexpansion rings. The opening in which the ferrule is yreceived is screw threaded and the metallic rings are compressed by a caulking tool vwhich upsets these metallic rings, outwardly kand inwardly, completely filling the threads Vand pressingagainst the condenser tube With an evenly distributed pressure, resulting in the establishment of awater tight and air tight oint, which, however, permits the tube to move back land forth'longitudinally a slight 'dist-ance under temperature variations,

without breaking the seal.

`located on tide water.

In many condenser installations the cooling water which flows through the tubes Vis contaminated, as it is usually taken from rivers or from the ocean where the plant is Considerable diiculty has been encountered heretofore due to disintegration ofthe tubes and deterioration of the packing itself, caused by exposure to air and to the eect of the air in the water, as Well as agitation and turbulence.

The metal of which the packing is formed is very thin and oxidizes when not protected, resulting in holes forming in the metal, in the course of time.

Metallic packing formed by the method described herein is protected against deterioration due to acid in the water, salts or other contaminating substances. For exaniple, cut edges of tin coated lead foil present a galvanic couple to electrolytes in solution, and the coating of varnish insulates this couple from the electrolyte. This coating is even more flexible than tin coated lead foil itself and is not broken mechanically without also breaking the foil. It is of such character that it is not damaged during the compression of the ring within the die. The metallic packing is not affected by the heat due to the presence of the exhaust steam which surrounds the condenser tubes.

Not only must the coated strip be capable of being rolled up and unrolled without sticking or tearing, but-also it must not stick to the condenser tube after it has been installed. After the coating has been finally formed, under proper conditions, it is not sticky.

The resin coating of Patent 1,714,725 has a longer life in the uses described than does the bare foil packing, but I have found in comparative tests that the resistance is greatly increased by adding fillers to the coating materials, such as barytes, Zinc oxide, iron oxide, lead oxide, silica, Zinc sulphide, bronze powder, Zinc dust, aluminum dust, graphite, lamp black, etc.

I prefer graphite, because it is electrically7 conductive and chemically inert. I have found that in coatings of the kind here referred to, there is electrical conductivity because of the presence of the carbon particles. Metals likewise give the same result, but these are subject under some conditions to corrosion forming products, like oxides, hydroxides, etc., which are more bulky than the original metal particle, and which products fill voids in the packing. Therefore, the use of metal is likely to result in the formation of some of the same quality of filler as is obtained when oxides and non-metallic fillers, such as pigments are first employed.

The use of conductive packing keeps the metal parts and the packing at more or less equal potentials, and minimizes electrolytic corrosion resulting from differences of potential.V

In lexplaining the invention I illustrate the fillerV by reference to graphite because it is the preferred iiller. When incorporated into the phenol condensation product, I employ a varnish made under the Byck Patent No.

1,590,079, using the commercial brand known Y as Bakelite XV 1410, this being found very In using the mixture some of the graphite may settle out, but suitable agitation will hold it in suspension.

In Fig. 5, the metal foil is indicated as 37 the coating as 38and the filler as 39.

The coating base may also be a cellulose derivative, such as nitrocellulose, suitably modiiied and prepared for application to form an adherent coating. Nitrocellulose alone in solution with a volatile solvent evaporates to forni a coating which adheres poorly or not at all to foil when the coated foil is deformed. I have discovered that the presence of varnish gums in the lacquer, such as is found in some commercial lacquers, causes suflicient adherence or suoli perfect adherence vai) that the foil may be deformed into a packing.

For example, a composition containing Rosin 1 part Acetone 40 parts Nitrocellulose Y solution containing 1 pound nitrocellulose per gallon 20 parts ence by employing a thinner coating, that is by using more solvent at the same time increasing the content of graphite, giving a suitable coating as follows:

Rosin 1 part Acetone V parts Nitrocellulose solution (1 Vpound nitrocellulose per gallon) 20 parts Graphite amorphous 4parts The packing referred to, as far as the mechanical features are concerned, is described soA more Vfully in lalton'P-atent 1,549,963,is

sued June 30, 1925, to Crane Packingv Gompany and the machine for making it is described in Cody Patents No. 17642A31yissued September 13, 1927, and No. 1,646,992, issued October '25, 1927. Y f

1What I claim is:

1. A metallic packing comprising amechanically deformed metallic'foil having a coating of a finally reacted synthetic resin of a flexibility at least equal tothe flexibility of the foil, and an electrically conductive filler incorporated in said resin.

2. A metallic packing` comprising av mechanically'deformed and compressed metallic foil having` a coating` of' finally reacted synthetic resin of a flexibility at least equal to the flexibility of the metal foil7 and an electricallyconductive filler incorporated in said resin. 'i l 3. A metallic packing` comprising' a inechanically deformed metal foil and a synthetic resin having a flexibility at leastequal to the flexibility of the metal foil, and an electrically conductive filler incorporated in said resin. 4:. A packing comprising, a plurality of layers of mechanically deformed metal foil each layer of which is covered with a coating of a finally reacted synthetic resin having a flexibility atleast equal to the flexibility of the foil, and an electrically conductive liller incorporated in said resin.

5. A metallic packing comprising-a mechanically deformediuetalli'c foil having` a coating' of a finally reacted synthetic resin of' a flexibility at least equal to the flexibility of the foil7 and graphite incorporated in said resin. Y

6. A metallic packing comprising a mechanically deformed and compressed metallic foil having a coating' of a finally' reacted synthetic resin of a flexibility at least equal to the flexibility of the metal foil.y and graphite incorporated in said resin.

7. A metallic packing comprising a mechanically deformed metal foil and a synthetic resin having a flexibility at least equal to the flexibility of the metal foil, and graphite incorporated inv said resin.

8. A packing comprising a plurality of layers of mechanically deformed metal foil each layer of Which is covered with a coating of a finally reacted synthetic resin havingr a flexibility at least equal to the flexibility of the foil, and graphite incorporated in said resin.

9. A metallic packing comprising a niechanically deformed metallic foil having an electrically conduct-ive protective film coating of insulating; material incorporating an electrically conductive filler. said film having a flexibility at least equal to the flexibility of theA foil.` n

10. A packing comprisinr a plurality of my name.

FENNO E. DE VRI-ES.

Images