US3034729A - Apparatus and method for coating pipe surfaces - Google Patents

Description

May 15, 1962 E. GRAY ETAL 3,034,729

APPARATUS AND METHOD FOR COATING PIPE SURFACES Filed April 9, 1958 4 Sheets-Sheet 1 IN VENTORS ARTHUR E .GRAY GRAHAM N. G-LEYSTEEN 2W 7AM May 15, 1962 Filed April 9, 1958 4 Sheets-Sheet 2 as 44 s 90 90 92 5o 40 Z 4 64 \//V////I l INVENT OR 5 ARTHUR E. GRAY GRAHAM N. GLEYSTEEN May 15, 1962 E. GRAY ETAL APPARATUS AND METHOD FOR COATING PIPE SURFACES 4 Sheets-Sheet 3 Filed April 9, 1958 INVENTORS ARTHUR E. GRAY GRAHAM N. GLEYSTEEN fiwl wf-ww ATTORNEYS May 15, 1962 E. GRAY ETAL 3,034,729

APPARATUS AND METHOD FOR COATING PIPE SURFACES Filed April 9, 1958 4 Sheets-Sheet 4 INVENTORS ARTHUR E. GRAY GRAHAM N. GLEYSTEEN ATTORNEYS United States Patent 3,034,729 APPARATUS AND METHOD FOR CGATING PIPE SURFACES Arthur E. Gray and Graham N. Gleysteen, Pittsburgh,

Pa., assignors, by mesne assignments, to Pittsburgh Chemical Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 9, 1958, Ser. No. 727,389 6 Claims. (Cl. 239-415) This invention relates to the coating of pipe interiors and more particularly to an improved apparatus and method for mixing and applying two separate materials, preferably of the type which will react with each other, to pipe interiors and the like.

While the invention is susceptible of general utility, in its more specific aspects it embodies an apparatus and method for mixing together two materials, one, a bitumen and an epoxy resin mixture and, another, a curing agent for the resin and subsequently distributing the mixed materials uniformly to a pipe surface. In dealing with such materials, it is essential to provide an apparatus which will effect a thorough mixing of the two materials efore the same are applied. Moreover, after the materials have been thoroughly mixed, it is also essential that they be efficiently applied to the pipe surface so as to preclude the formation of voids and other defects in the coating.

The present invention is more particularly concerned with the problem of applying or distributing the mixed materials to the pipe surface to be coated. Where the interior of the pipe is to be coated, distribution can be conveniently accomplished with the use of centrifugal force. Accordingly, the present application discloses apparatus whereby the mixed materials are applied to pipe interiors by throwing or moving the mixed materials outwardly from a central source through rotation of a distributing member so that it will be evenly deposited by the centrifugal force of the rotating member onto the interior of the pipe.

While centrifugal force distribution is readily available to be used when coating pipe interiors, it is quite apparent that this action can not be utilized to coat the exterior surface of the pipe. Thus, an apparatus employing centrifugal force for the application of the mixed material is limited in its utility in that it is completely incapable of use in coating pipe exteriors.

Accordingly, it is an object of the present invention to provide an apparatus of the type described which can be easily adapted for use in applying coatings to either the exterior or interior surface of pipes and the like.

Another object of the present invention is the provision of an apparatus of the type described having an improved mixture distributing nozzle suitable for application to either the exterior or the interior of a pipe or the like.

Still another object of the present invention is the provision of an apparatus of the type described having improved material distributing means which is simple in construction, efficient in operation and, economical to manufacture and maintain.

These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.

The invention may best be understood with reference to the accompanying drawings wherein illustrative embodiments are shown.

In the drawings:

FIGURE 1 is a somewhat schematic vertical sectional asses/2s Patented May 15, 1962 view of an apparatus embodying centrifugal force to distribute the material to a pipe interior or the like;

FIGURE 2 is an enlarged fragmentary side elevational view, partly in section, illustrating the applicator head of the apparatus;

FIGURE 3 is a cross-sectional view taken along the line 33 of FIGURE 2;

FIGURE 4 is a cross-sectional view taken along the line 44 of FIGURE 2;

FIGURE 5 is a fragmentary side elevational view, partly in section, illustrating a modification of the discharge nozzle of the applicator head;

FIGURE 6 is a view similar to FIGURE 5 illustrating still another modification of the nozzle of the applicator head and a modified form of the rotary distributor;

FIGURE 7 is a fragmentary side elevational view of still another modified form of the rotary distributor;

FIGURE 8 is a view similar to FIGURE 6 illustrating still another modified form of the rotary distributor;

FIGURE 9 is a cross-sectional view taken along the line -9 of FIGURE 8;

FIGURE 10 is a somewhat schematic side elevational view partly broken away illustrating an apparatus, embodying the principles of the present invention, as used in applying coatings to the exterior surface of a pipe or the like;

FIGURE 11 is an enlarged, fragmentary, side elevational view of the apparatus showing the distributing nozzle in section;

FIGURE 12 is a fragmentary front elevational view of the apparatus showing the distributing nozzle in section;

FIGURE 13 is a bottom view of the apparatus;

FIGURE 14 is a fragmentary, side elevational view of the apparatus, partly in section, showing the same as modified for use in applying coatings to the interior surface of a pipe or the like;

FIGURE 15 is a view similar to FIGURE 14 showing a schematic arrangement for effecting rotary and longitudinal movement of the pipe relative to the apparatus; and

FIGURE 16 is a cross-sectional view taken along the line 1616 of FIGURE 15.

Referring now more particularly to FIGURE 1 of the drawings, there is shown an apparatus, generally indicated at 10, which includes an applicator head, generally indicated at 12, arranged to apply a coating of material to the interior of a pipe 14. Means, generally indicated at 16, is provided for supporting the pipe 14 in operative position relative to the applicator head 12 and for effecting relative longitudinal movement between the pipe and the applicator head during the operation of the latter so that the material distributed by the head will be received on the pipe as an even coating throughout the interior thereof. The means 16, schematically illustrated in the drawings, is'operable to elfect a longitudinal movement of the pipe 14 relative to the stationarily mounted applicator head 12 and it will be understood that this arrangement is merely exemplary and that other means may be provided for this purpose.

In the apparatus illustrated in FIGURE 1, the applicator head 12 is stationarily mounted in cantilever fashion on one end of an elongated, generally U-shaped frame member 18. The other end of the frame member 18 is rigidly secured to a suitable base or the like 20. The applicator head is arranged to receive two separate materials, one of which preferably comprises a bitumen and epoxy resin mixture and the other of which comprises a curing agent for the resin. As shown in FIGURE 1, the bitumen and epoxy resin mixture may be contained in a hopper 22 having a pump 24, driven by a suitable motor 26, connected to the discharge end of the hopper and arranged to feed the bitumen and epoxy resin mixture under pressure through a conduit 28 to the applicator head 12. The curing agent is preferably contained within a hopper 30 having a pump 32, driven by suitable motor 34, connected to the discharge end thereof and arranged to deliver the curing agent to the applicator head through a conduit 36. As shown in FIGURE 1, the conduits 28 and 36 may be suitably mounted within the U- shaped frame member 18.

Referring now more particularly to FIGURE 2, the applicator head 12 includes a cylindrical body 38 having its rear end counterbored and threaded, as indicated at 40, so as to threadedly receive a rear end wall 42. The end wall 42 is provided with a pair of longitudinally extended spaced passageways 44 and 46 arranged to be connected with the ends of the conduits 28 and 36 respectively. The opposite end of the cylindrical body 38 of the applicator head is closed by a forward end wall 48. The rear end wall 42 is centrally apertured, as at 50, and the end wall 48 is likewise centrally apertured, as indicated at 52, so as to receive a shaft 54 which extends axially through the applicator head. As best shown in FIGURE 1, the shaft 54 extends rearwardly within the U-shaped frame member 18 and its rearward end is journaled by any suitable means, such as bearing blocks 56, and connected with a motor 58 to be driven thereby.

The forward end of the shaft extends into and is journaled within the applicator head by any suitable means. As shown in FIGURE 2, the end walls 42 and 48 are preferably recessed to receive ball bearing assemblies 60 and 6 2 respectively, to accomplish this purpose, which engage and serve to journal the shaft 54 within the applicator head although, it will be understood that other journal means, such as sleeve bearings or the like, may be employed, if desired.

The interior of the cylindrical body 38 between the end walls 42 and 48 defines an elongated cylindrical mixing chamber 64 within which the materials introduced therein through the passageways 44 and 46 are intimately intermixed. To effect this mixing of the two materials, the passageway 44 for the bitumen and epoxy resin mixture has a short tube 66 connected therewith which is arranged to direct the material passing through the passageway 44 into the mixing chamber 64 in an area adjacent the shaft 54 or axially within the mixing chamber. The outlet of the passageway 46 has a deflector block 68 connected therewith which is arranged to direct the curing agent issuing therefrom outwardly toward the periphery of the mixing chamber.

Mounted on the shaft 54 within the mixing chamber 64 adjacent the rear end wall 42 is a rear mixing blade assembly 70, which preferably may comprise a disk of metal having blades struck therefrom and bent so as to impart not only a rotary motion to the materials within the mixing chamber, but a forward longitudinal motion as well. The blade assembly 70 is secured to the shaft by any suitable means, such as a rigid central hub 72 having a set screw 74 threaded therein for engagement with the shaft. Mounted in spaced relation on the shaft 54 forward of the rear mixing blade assembly 70 is an intermediate mixing blade assembly 76 of substantially similar construction and including a rigid hub 78 having a set screw 80 threaded therein for securing the blade assembly to the shaft. The blade assembly 76 preferably has blades struck from a disk of metal and bent in an opposite direction from those of the blade assemblies 70 so that in operation, the material is given not only a rotary motion, but a rearward longitudinal motion as well. Disposed within the mixing chamber 64 adjacent the forward end wall 48 thereof is a forward blade assembly 82, which preferably is identical with the blade assembly 70 and includes a rigid hub 84 having a set screw 86 threaded therein for engaging the shaft 54. Like the rear blade assembly 70, the forward blade assembly 82 is arranged to impart a rotary motion and a forward longitudinal motion to the material within the mixing chamber. To further aid in agitating the materials within the mixing chamber 64, there is provided a plurality of circumferentially spaced, longitudinally extending baflles 88 suitably secured to the cylindrical body by any suitable means, such as set screw 90 or the like.

In order to discharge the material from the mixing chamber, the forward end wall 48 is provided with a plurality of circumferentially spaced discharge orifices or apertures 92 through which the material discharges into a nozzle 94. The nozzle 94 includes a frusto-conical intermediate portion 96 having a longitudinally extending cylindrical flange 98 extending from the rear end thereof, which is interiorly threaded to engage exterior threads formed on the forward end of the cylindrical body 33. Extending from the forward end of the frustro-conical portion 96 is a cylindrical portion llfitl'having an outwardly extending radial flange 102 formed on the forward end thereof.

The shaft 54 extends through the mixing chamber 64 and outwardly through the cylindrical portion of the nozzle 94 and and has its outer end arranged to receive a rotary distributor 104. The rotary distributor 1114 includes a hollow cylindrical member 106 having the forward end thereof provided with a centrally apertured end wall 1% arranged to receive the outwardly extending end of the shaft 54 and to be rigidly secured thereto by any suitable means, such as a nut 110 threaded on the end of the shaft. The opposite end of the cylindrical member 106 extends over the cylindrical portion 100 of the nozzle and has an inwardly directed radial flange 112 formed thereon which is disposed in spaced relation to the nozzle. Extending through the hollow cylindrical member 106 is a plurality of circumferentially spaced narrow apertures 114. As best shown in FIGURES 2 and 5, for a two inch diameter cylindrical member 106 the apertures are preferably arranged in six rows around the circumference of the member 106 and each row preferably contains approximately 15 apertures. It will be understood that the number of rows provided will increase with an increase in the diameter of the member 106.

Referring now more particularly to FIGURE 5 in the drawings, there is shown a slight modification of the nozzle 94 in which a separate cylindrical nozzle outlet portion 116 is provided. The inner end of the cylindrical outlet portion 116 may be suitably threaded, as at 1 18, to engage cooperating threads formed in the frusto-conical portion of the nozzle 94. The cylindrical outlet portion 116 includes an outwardly extending radial flange 120 which is disposed near the rear end of the rotary distributor 104.

in FIGURE 6, there is shown a modified nozzle 122 which includes a frusto-conical portion 124 terminating in an outlet 126. A modified rotary distributor 128 is secured to the shaft 54 extending outwardly through the outlet 126 and includes a hollow cylindrical member 130 having a centrally apertured forward end wall 132 arranged to receive the end of the shaft 54 and to be fixedly secured thereto by any suitable means, such as a nut 134. The cylindrical member is open at its opposite end and has a series of circumferentially spaced longitudinally extending elongated slots 136 formed therein through which the material is discharged by centrifugal force.

FIGURE 7 illustrates a further modified form of a rotary distributor 138 which is similar to the distributor 104 but includes a series of circumferentially spaced apertures 140 arranged in spaced spiral rows about the circumference of the hollow cylindrical member.

FIGURES 8 and 9 illustrates a further modified form of distributor 142, which comprises a concavo-convex disk 144 having a central aperture formed therein for receiving the end of the shaft 54 and to be fixedly secured thereto, as by a nut 146. The disk 144 has its concave surface facing the discharge outlet of the nozzle and is arranged to receive the material issuing therefrom and to distribute the same into the interior of the pipe by centrifugal force.

In order to facilitate relative longitudinal movement between the pipe 14 and the applicator head 12, the latter is provided with a ring 148 which is arranged to engage the exterior surface of the cylindrical body 38 and to be fixed thereto, as by a set screw 150, in different positions of adjustment. Extending outwardly from the ring 148 are a series of circumferentially spaced guide fins 152 arranged to engage the interior surface of the pipe 14 and to maintain the applicator head in concentric relation therewith. As shown in FIGURE 3, three guide fins 152 are provided and it will be understood that more or less than three may be utilized, if desired.

The means 16 illustrated in FIGURE 1 for effecting relative movement between the pipe 14 and applicator head includes a U-shaped saddle or guide member 154 which is arranged to receive the pipe and to support the same for longitudinal movement. The saddle 154 includes a central elongated slot 156 with in which a cable 158 may extend. The cable 158 has a hook 169 on one end thereof for engaging one end of the pipe and the opposite end thereof is trained about a pulley 162 and a winch 164 powered by a suitable motor 166 or the like.

In the operation of the apparatus illustrated in FIGURE 1, the pipe to be lined is moved within the saddle 154 over the applicator head 12 with the hook 16 1 connected with the rear end thereof and the cable 158 extended from the winch 164 and then motors 26, 34, 58 and 166 are started to commence operation. It will be noted that pumps 24 and 3 2 driven by the motors 26 and 34 respectively are operable to introduce the bitumen and epoxy resin mixture from the hopper 22 and the curing agent from. the hopper 30* through the conduits 28 and 36 respectively into the mixing chamber 64 under pressure. The bitumen and epoxy resin mixture is somewhat heavier than the curing agent and, hence, directed axially into the chamber by means of the tube 66. The curing is directed to the periphery of the mixing chamber by the deflector block 68. Thus, the supply of the heavier material is toward the center of the chamber, while the supply of the lighter material is around the periphery thereof. The blades of the blade assemblies 70, 76 and 82 set the material within the mixing chamber into rotary motion and such rotary motion effects an intermixing of the two materials as a result of centrifugal force. That is,

.since the heavier material tends tomove toward the periphery as a result of the centrifugal action, it will become intermixed with the lighter material supplied therein. In addition to the rotary motion imparted by the blade assemblies, it will be noted that the rear blade assembly serves to impart a forward longitudinal movement to the material within the mixing chamber as Well. The intermediate blade assembly 76 has the opposite effect and serves to move the two materials in a rearward longitudinal direction so that there is additional agitation and mixture due to this arrangement. Finally, the for- Ward blade assembly 82 is arranged to impart a forward longitudinal movement to the material, which is opposed to the longitudinal movement of the intermediate blade so that still more agitation and intermixing of the materials is obtained in this manner. As noted above, all three of the blade assemblies serve to impart a rotary movement to the material within the mixing chamber and the provision of the baffles 88 serves to agitate the materials in rotary motion so that they are not separated as a result of centrifugal action, but are continuously agitated. Finally, the movement of the materials outwardly through the restricted orifices 92 achieves a still further intermixing as a result of the baffling eifect of portion of the walls defining the orifices. The total effect of these four distinct intermixing actions, that is, (1) the movement of the heavier material into the lighter material as a result of centrifugal action, (2) the agitation caused by the longitudinal movements imparted in ops posite directions by the blade assemblies, (3) the agitation of the-rotating mass caused by the baffles 88 and (4) the agitation of the mass caused by its passage through the orifices 92, serves to intimately intermix the two materials supplied within the mixing chamber.

Since the materials are supplied within the mixing chamber 64 under pressure by the operation of the pumps 24 and 32, they will be discharged therefrom under such pressure, after being thoroughly mixed, as indicated above, through the outlet apertures 92 within the forward end wall 48. The mixed materials then enter within the frustro-conical portion of the nozzle and issue outwardly into the rotary distributor 1114 through the cylindrical nozzle portion around the shaft 54. The material within the rotary distributor 104 discharges through the apertures 114 and the hollow cylindrical member 106 due to the centrifugal force created as a result of the rotary motion of the distributor.

In this manner, the two materials are first intimately intermixed and the-n subsequently distributed to the interior of the pipe 14. It will be understood that the pipe 14 is moved at a uniform rate of speed during the operation of the applicator head so that a coating of uniform thickness is applied to the interior thereof as the mixed materials discharge through the apertures in the distributor 104. The arrangement of apertures illustrated in the distributor 164 shownin FIGURES 1-4 is preferable and the provision of the flange 112 serves to prevent spillage or leakage of the material axially outwardly from the hollow cylindrical member 106. The distributor 128 illustrated in FIGURE 6 achieves satisfactory results and does not require the utilization of the inwardly directed flange. The distributor 138 of FIGURE 7 operates quite similar to the distributor 104 and is preferable for some applications. The concavo-convex disk 144 of FIGURE 8 is particularly advantageous due to its sim plicity of construction. This distributor merely receives the material isssuing from the nozzle outlet and moves the same outwardly by centrifugal action.

In general, the mixed materials must have sufficient viscosity to adhere to the pipe interior without running. However, the less viscous the mixed materials are, the more readily they can be handled to completely cover the pipe interior uniformly throughout. It is also desirable to operate the applicator head at a medium to high rpm. Furthermore, it is preferable to operate the pump at a relatively low rate and with a low speed movement between the applicator head and pipe so as to apply a relatively thick coating to the interior of the pipe of the order of 15 mils or more. With such an application, an uninterrupted coating of uniform thickness is applied to the pipe.

In order to reduce the viscosity of the epoxy resinbitumen composition, there can be added a solvent, or thinner, such as an aromatic hydrocarbon, or mixtures of aromatic hydrocarbons, e.-g., toluene, xylene, or solvent naphthas, for example. The epoxy ethers or resins suitable for use in the compositions of the invention contain along with ethereal oxygen, glycidyl groups in such quantity that the material has a 1,2-epoxy equivalency in the average molecule of greater than one. By the epoxy equivalency, reference is made to the average number of 1,2-epoxy groups contained in the average molecule of the ether.

A preferred group of epoxy ethers for use in the invention is prepared by reacting a dihydric phenol with epichlorhydrin in alkaline solution. These products are of resinous character and in general are solid materials at normal temperature (20-30 0.). Any of the various dihydric phenols are used in preparing these glycidyl '7 ethers, including mononuclear phenols like resorcinal, catechol, hydroquinone, etc., on polynuclear phenols like his (4-hydroxyphenyl -2,2-propane bis-phenol) 4,4'-dihydroxy benzophenone, bis-(4-hydroxyphenyl) -1,1-ethane,

bis- 4-hydroxyphenyl) 1,1-isobutane,

bis- 4-hydroxyphenyl) -2,2-butane,

bis- (4-hydroxy-2-methylphenyl) -2,2-propane, bis-(hydroxy-Z-tertiary butyl phenyl)-2,2-propane, bis- 2-dihydroxynaphthyl) -methane,

1,5-dihydroxy napthalene, etc.

The product may be represented by the formula:

wherein n is an integer, preferably from 1 to 7, and R represents the divalent hydrocarbon radical of the dihydric phenol. The preferred epoxy ethers for use in the invention are those having epoxy values no less than 0.20 (pyridinium chloride method), and melting points no greater than 80 C. (Durrans mercury method). The preferred phenol is bis-phenol A.

Less preferably, there can be used 1,2-epoxy-containing polyethers of polyhydric alcohols, such as polyglycidyl ethers thereof, like the diglycidyl ether of ethylene glycol, propylene glycol, trimethylene glycol, diethylene glycol, triethylene glycol, glycerol, dipropylene glycol and the like. Other typical ethers of this class include glycidyl ethers of polyhydric alcohols having a 1,2-epoxy equivalency greater than one, such as the polyglycidyl ethers of glycol, diglycerol, erythritol, pentaglycerol, mannitol, sorbitol polyallyl alcohol, polyvinyl alcohol, and the like.

In general, the glycidyl ether resin will have an epoxy equivalency greater than 1 and usually less than 2. The epoxy equivalency may be defined as the number of epoxy groups per molecule in contrast to the epoxy value which is the number of epoxy groups in 100 grams of the resin.

While the epoxy resin can be utilized by itself, it has been found preferable to employ a mixture of the epoxy resin and a bituminous material, such as coal tar pitch. The pitch can be present, if desired, as coal tar or a liquid organic vehicle, such as aromatic high flash naphtha creosote oil, ketones, chlorinated solvents, toluene or xylene, can be added to the pitch. Generally, to 90 parts of epoxy resin and 90 to 10 parts of pitch based on 100 parts by weight of the total epoxy resin-pitch content are employed. In addition to the coal tar pitch and epoxy resin, there can also be added finely divided fillers, e.g., silica, talc, clay, slate, flour, diatomaceous earth, mica, etc., as well as solvents, as set forth previously. The epoxy resin-bituminous composition is introduced through conduit 28 to the applicator head 12.

The curing agent can be a polyfunctional amine, such as ethylene diamine, diethylene triarnine, benzyl dimethylamine, ethylene triamine, 3 dimethylaminopropylamine, 3-diethylaminopropylamine, tetraethylene pentamine, triethylene tetramine and the like. Additional curing agents include N-hydroxyethyl diethylenetriamine, tri-(dimethylaminomethyl) phenol, m-phenylene diamine, dicyandiamide, melamine, piper-azine, diacetone diamine, 4,4'-diaminodiphenyl sulfone, sodium hydroxide, potassium hydroxide, sodium phenoxide, acid materials preferably having a plurality of acid groups, e.g., oxalic acid, phthalic anhydride, citric acid, tricarbyllic acid, aconitic acid, itaconic acid, malic acid, diglycollic acid, phosphoric acid, n-butyl dihydrogen phosphate, diethyl ortho phosphate, hexaethyl tetraphosphate, Friedel-Crafts metal halides, e.g.,. aluminum chloride, zinc chloride, ferric chloride, boron trifiuoride, boron-fluoride-diethyl ether complex, boron-fluoride-phenol complex, diisocyanates, (e.g., 2,4- toluene diisocyanate) and polyamides, e.g., long chain fatty acid amides, such as Versamid 115 and Versamid 125. The curing agent is introduced through conduit 36 to the applicator head 12.

The curing agents may be used in various amounts, although they are usually employed in the range of from 0.05 to 0.25 part per part by weight of epoxy resin. While the bituminous material is normally added together with the epoxy resin through conduit 28, it is possible to add the bituminous material with the curing agent through conduit 36. The resin and curing agent, however, should always be added through separate lines to the applicator head.

While, as previously stated, the ratio of epoxy resin to bituminous material, e.g., coal or tar pitch, can be widely varied, usually from 15 to 50 parts of resin and from to 50 parts of pitch based on parts of epoxy resin-pitch content are employed.

Frequently, it is desirable to add a minor amount of chlorinated rubber (Parlon) or rubber hydrochloride to the composition. Generally, the chlorinated rubber or rubber hydrochloride is used in an amount of 0.1 to 5% of the total composition by weight.

Thixotropic agents, e.g., labosil (a collodial silica formed in a high temperature vapor phase flame hydrolysis process which produces an extremely fine product with a particle diameter of about 15 millimicrons; chemically it is practically a pure silica with an average SIO content of 919 to 99.7%) and'quaternary ammonium clays, e.g. Bentone 34 (dimethyl dioctadecyl ammonium bentonite) can also be added in an amount of 1 to 5% of the total composition.

Unless otherwise stated, all parts are by weight. In a specific example using the apparatus of FIGURE 2, through conduit 28 there was pumped component A, a

r mixture of 30 parts of an epoxy ether resin from bisphenol A and epichlorhydrin (melting point 9 C. and epoxy value 0.50), 0.6 part Parlon, 29.4 parts of coal tar pitch, 20.0 parts of aromatic high flash naphtha, 9 parts mica, 10 parts of talc and 1 part of cabosil. Simultaneously, through conduit 36, there were pumped component B, a mixture of 5 parts of diethylene triamine dissolved in 5 parts of mixed xylenes. Thus, the material was pumped through conduit 28 in an amount 10 times as much as that pumped through conduit 36. The drive shaft 54 was rotated at a speed of 4350 rpm. Utilizing these conditions, blemish-free coverage of a 3 diameter pipe was obtained by moving the pipe at a rate to obtain an 18 mils coverage.

In another example where component A was diluted with 12.5% by volume of xylene but the ratio of feed of component A to component B was maintained at 10 to 1, blemish-free coverage of the 3 diameter pipe was obtained when the shaft was rotated at a speed of 2333 rpm. and the pipe was moved at a rate to give a coverage of 16 mils thickness.

The above description is disclosed in copending application Serial 677,468, filed August 12, 1957 by Arthur G. Gray. The present invention is more particularly concerned with certain improvements in the applicator head 12 which render the same applicable to coat the exterior surfaces of pipes as well as the interior surfaces thereof.

Referring now more particularly to FIGURES 10-13, there is shown an applicator head 200 embodying the principles of the present invention. In general, the head is the same as the head 12 previously described except that the nozzle 94 and rotary distributor 104 are replaced by an adapter member 202 and a nozzle 204 of improved construction. Thus, the applicator head 200 includes the mixing chamber 64 wherein the materials are separately supplied under pressure to be intimately intermixed by the four actions previously noted.

The mixed material issuing through the orifices 92 is received in the adapter member 202 which preferably includes a large interiorly threaded end 206 arranged to equal to the total interior cross-sectional area of the orifices 92. The opposite end of the coupling 210 is rigidly secured, as by welding or the like, to the central portion of a pipe section 212 of similar size. The pipe section 212 is formed with a small but even bend, along a circular arc of large radius. The curvature of the bend is such that when cut longitudinally in half along a plane surface perdpendicular to the plane of the curve of the arc, the interior cross-section of the pipe at either end is about one-half of the interior cross-section at its midpoint. The cut side of the pipe section 212 is machined and fitted with a flat machined plate 214, the latter being secured in a position disposed in a plane perpendicular to the axis of the coupling 210, by any suitable means, such as screws 216 or the like.

The open ends of the pipe section 212 are closed by rigidly securing therein as by welding or the like, two end disks 218 of generally semi-circular configuration. The material in the nozzle is arrangedto be discharged through a desired number of evenly staggered slits 220 formed in the plate 214 between the ends thereof. As best shown in FIGURE 13, three such slits are provided although, it will be understood that this number may be increased, if desired.

FIGURE 10 illustrates one arrangement for utilizing the applicator head 2% to apply a coating of the type previously described to the exterior surface of a pipe 222. It will be understood that the essential condition of the arrangement is to effect a relative longitudinal and rotary movement between the pipe and applicator head and that this condition can be satisfied by various structural arrangements. In the arrangement shown, the head 2% is mounted in a fixed position and the pipe is moved past the head with a rotary and longitudinal movement to effect the essential relative movement. It is possible to rotate the pipe only While moving the head longitudinally with respect thereto or to hold the pipe stationary and rotate the head together with such longitudinal movement.

As shown in FIGURE 10, the pipe is carried by a pipe carrier or frame 224 appropriately supported by wheels 226 riding in suitable longitudinally extending tracks 228 or the like. One end of the pipe is supported on the frame by a chuck 230 or the like arranged to engage within the pipe end and having a shaft 232 extending therefrom. The shaft 232 is suitably connected with a variable speed motor 234 mounted on the adjacent end of the frame.

The opposite end of the pipe is supported from the frame 224 by any suitable means, such as a flanged disklike element 236 engageable within the pipe end and rotatably carried by a bearing member 238 detachably mounted on the adjacent end of the frame 224 in any appropriate manner.

Longitudinal movement of the pipe 222 is accomplished by moving the wheeled frame along the tracks 228 by any suitable means. As shown, there is provided a motor 240 having a cable reel 242 mounted on its drive shaft. A cable 244 is wound on the reel 242 and extends upwardly therefrom around a pulley 246 and then back to the far end of the frame where it is rigidly secured, as indicated at 248.

In operation, the applicator head 200 is mounted in fixed position and provided with suitable pumps and motors in a manner similar to that shown in FIGURE 1. The wheeled frame 224 having a pipe 222 mounted thereon is initially positioned so that the applicator head nozzle 204 discharges adjacent one end thereof a desired distance from the exterior surface thereof. Actuation of the motors 234 and 240 at predetermined desired speeds effects both rotary and longitudinal movement of' the pipe relative to the nozzle. By relating the discharge of material from the nozzle to the speed of rotational and longitudinal movement of the pipe, an even coating of material of a desired thickness is applied to the entire exterior surface of the pipe.

In FIGURES 14-16 there is shown an arrangement whereby the applicator head 200 can be modified to apply a coating to the interior of a pipe. The nozzle 204- is utilized as in the arrangement disclosed in FIGURES 10-13. The adapter member 202 is replaced by an adapter member 250 having a large interiorly threaded end 252 arranged to be engaged on the exterior threads formed on the forward end of the cylindrical body 38. As before, the adapter member necks down throughout its extent from the end 252 and terminates in a relatively small, interiorly threaded opening 254. However, the opening is disposed adjacent the periphery of the large end 252 rather than being concentric therewith.

Threadedly engaged within the opening 254 of the adapter member is one end of a short horizontal pipe coupling 256, the other end of which is threadedly engaged within an elbow 258. A vertical pipe coupling 260 is threadedly connected with the opposite end of the elbow and extends downwardly therefrom. The lower end of the vertical coupling 260 is threadedly received in the upper end of a sleeve 262, the lower end of which is connected with the threaded end of the coupling 210 of the nozzle. The length of the horizontal and vertical pipe couplings are such as to dispose the nozzle slits 220 as close as conveniently possible to the adapter member and a desired distance away from the pipe interior to be coated.

Again, in order to utlize the modified applicator head 26% to apply a coating to a pipe interior, an arrangement must be provided to eifect both rotary and longitudinal movement relatively between the applicator head and the pipe. While any suitable construction may be employed, the arrangement shown includes a generally troughshaped pipe carrier 264 supported at opposite ends by wheels 266 suitably mounted thereon and arranged to ride on longitudinally extending tracks 268 or the like.

Mounted in the lower portion of the pipe carrier at opposite ends thereof is a pair of pipe rotating and supporting rollers 270. The rollers are driven by any suitable means to impart rotation to a pipe 272 received in the carrier. As shown such means includes a variable speed motor 274 mounted on one end of the carrier and having a longitudinally extending shaft 27 6 drivingly connected therewith, driving rollers 278 being fixed to the shaft 276 in rolling contact with the rollers 270. In order to stabilize the pipe Within the carrier, idler rollers 280 are journaled in opposite sides of the pipe carrier adjacent each roller 270.

Longitudinal movement of the carrier is efiected by means of a motor (not shown) similar to the motors 166 and 240 previously described, such motor being arranged to reel in a cable 282 fixed, as at 284, to the pipe carrier.

The modified applicator head is fixedly mounted in a manner similar to that shown in FIGURE 1. Since both rotary and longitudinal movement are involved, the fins 152 previously described are replaced by ball bearings 286. As shown there are four ball bearings provided in circumferentially spaced relation about the exterior of the cylindrical body 38, each ball bearing 288 being mounted within a housing rigidly secured as by welding or the like to the body 3-8.

The operation of the arrangement shown in FIGURES 14-16 is similar to that previously described in connection with the arrangement of FIGURES 10-13 so that a detailed description thereof is not believed to be necessary. Briefly, the pipe 272 is moved to the right, as viewed in FIGURE 14, while motor 274 is actuated to rotate the same through shaft 276 and rollers 270 and 278. By relating the discharge of material through the nozzle slits with the speed of rotative and longitudinal pipe travel, an even coating of a desired thickness is applied to the interior surface of the pipe.

It will thus be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

We claim:

1. In an apparatus of the type described, the combination comprising an applicator head defining an elongated mixing chamber, means communicating with one end of said chamber for directing separate materials under pressure therein, rotary shaft means extending longitudinally within said mixing chamber, blade means carried by said shaft means for mixing the separate materials entering said mixing chamber, the opposite end of said chamber having orifice means therein through which the mixed materials are discharged from the mixing chamber, an adapter member fixed to said applicator head exterior of said chamber to receive the mixed material discharging therefrom, said member having a reduced end extending from said chamber and a nozzle fixedly carried by said member in communication with the reduced end thereof for receiving at one end the material from the reduced end of said member and discharging the same directly onto a pipe surface, whereby both the interior and exterior of a pipe may be coated by the material ejected from said nozzle.

2. The combination as defined in claim 1 wherein said nozzle comprises an elongated pipe section having a pipe coupling rigidly secured to one side thereof intermediate its ends in communication \m'th the hollow interior thereof, said section having its opposite side terminating longitudinally along a plane perpendicular to the axis of said pipe coupling, said pipe section being extended longitudinally in the plane of said pipe coupling axis so that the interior cross-sectional area adjacent said coupling is approximately twice the interior cross-sec tional area adjacent its ends, means closing the ends of said pipe section and a flat plate fixed to the longitudinally terminating side of said pipe section and having discharge openings therein.

3. The combination as defined in claim 2 wherein said discharge opening comprises a plurality of staggered longitudinally extending slits.

4. In an apparatus of the type described, a nozzle comprising an elongated pipe section extending longitudinally into an arcuate configuration and having a central inlet opening in the convex side of its curvature, said section terminating longitudinally along its concave side in a plane perpendicular to a plane passing through the axis of said pipe section so that the interior cross-sectional area adjacent said inlet opening is approximately twice the cross-sectional area adjacent its ends, means closing the ends of said pipe section, and a plate fixed to the longitudinally terminating side of said pipe section and having discharge openings formed therein.

5. A nozzle as defined in claim 4 wherein said discharge openings comprise transversely staggered longitudinally extending slits.

6. In an apparatus of the type described, the combination comprising an applicator head defining an elongated cylindrical mixing chamber for receiving separate materials one of which is heavier than the other, means adjacent one end of said chamber for directing the heavier material into said chamber adjacent its axis, means adjacent said one chamber end for directing the other material into said chamber adjacent its periphery, an axial shaft rotatable within said chamber, spaced blade means on said shaft operable to impart a rotary motion to the materials within said chamber so as to cause an intermixing of the materials as a result of the centrifugal action of the heavier material with respect to the other material and to impart axial movements to the materials in opposite directions so as to effect further intermixing, longitudinally extending baffie means on the interior periphery of said mixing chamber operable to impart turbulence to the materials within said chamber passing thereby with a rotary motion so as to effect still further intermixing, means adjacent the other end of said chamber through which the intermixed materials within said chamber are discharged, a necked down member fixed in surrounding relation to the other end of said chamber to receive the materials discharging therethrough, and a nozzle having its one end fixed to said necked down member, said nozzle having discharge openings at its other end for discharging material therethrough to a pipe surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,013,364 Behm Jan. 2, 1912 1,039,383 Goughnour Sept. 24, 1912 1,186,226 Parker June 6, 1916 1,208,165 Kent Dec. 12, 1916 1,895,890 Meng Jan. 31, 1933 2,185,570 Ridley Jan. 2, 1940 2,280,751 Davis Apr. 21, 1942 2,287,448 Perkins June 23, 1942 2,575,353 MacEvoy Nov. 20, 1951 2,578,667 Brennan Dec. 18, 1951 2,814,827 Snow et a1. Dec. 3, 1957 2,839,026 Matheny June 17, 1958

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