US3311971A

US3311971A - Vessel lining method

Info

Publication number: US3311971A
Application number: US338128A
Authority: US
Inventors: Harold E Hicks; Charles L Hibbeler
Original assignee: Nooter Corp
Current assignee: Nooter Corp
Priority date: 1964-01-16
Filing date: 1964-01-16
Publication date: 1967-04-04
Anticipated expiration: 1984-04-04

Description

April 4, 1967 H. E. HICKS ETAL 3,311,971

VESSEL LINING METHOD Filed Jan. 16, 1964 5 Sheets-Sheet l INVENTORS. Y #42412 46. H/GkS BY C/lfl/FLES All/B85451? Myw M April 4, 1967 H. E. HICKS ETAL 3,311,971

April 4, 1967 E. HICKS ETAL VESSEL LINING METHOD Filed Jan. 16, 1964 5 Sheets-Sheet 3 INVENTORS. H/MML] 4e. Ana/ 5 BY 67/0/9165 (Ml/881E258 Wjw MW #770 lam-ya, v

April 4, 1967 H. E. HICKS ETAL 3,

VESSEL LINING METHOD Filed Jan. 16, 1964 5 Sheets-Sheet 5 I I P A INVENTORJ. HFIFWLD E HICKS BY 'flflPAE- 46 223545? United States Patent 3,311,971 VESSEL LHNING METHQD Harold E. HiCliS, Kiriswood, and Charles L. Hihheler, Lemay, Mm, assignors to Nooter Corporation, St. Louis, Mo., a corporation of Missouri Filed Jan. 16, 1964, Ser. No. 338,128 3 Claims. (Cl. 29-523) The present invention relates to a method of lining vessels. The present invention also relates to a method of making multiwall pressure vessels.

One of the problems in lining vessels or large tanks as well as in making multi-wall pressure vessels is achieving intimate contact between the tank inner wall and the corrosion resistant lining throughout the surface area of the tank. The present invention achieves this by expanding a continuous corrosion resistant liner (stainless steel, zircalloy, zirconium or titanium, etc.) by means of a rotating pressurized roller which expands the liner into intimate contact with the inner surface of the vessel. In achieving this structure, a vessel which might be 30 feet long, 2 feet in diameter, and several inches thick is provided with a liner which may be up to /2 inch thick and which is of slightly less outside diameter than the inside diameter of the vessel. The liner is slipped into the vessel, the mechanism is placed within the liner, hydraulic pressure of the desired force is applied to the rollers, and the mechanism is rolled through the vessel to force the liner outwardly into intimate contact with the inner surface of the tank. The ends of the liner then may be anchored in place, and additional rolling of the liner will pre-stress the liner in a longitudinal direction as well as in a circumferential direction.

One of the principal objects of the present invention is to provide a method of applying a liner to a vessel whereby the liner is in intimate contact with the inner surface of the vessel to which it is applied. Another principal object of the present invention is to provide a method of making a multi-wall vessel wherein the liner layers are given different degrees of pre-stress which may be in the longitudinal as well as the circumferential direction.

Another object is to provide a method of using a rotatable roller device which may be aligned with the helical angle of rotation to prevent end thrust on the feed screw and to eliminate wear on the thrust washers holding the roller in position.

These and other objects and advantages will become apparent hereinafter.

The present invention comprises a method of applying a liner to the inside of a vessel by expanding the liner outwardly into intimate contact with the vessel.

In the drawings wherein like numbers refer to like parts wherever they occur:

FIG. 1 is a sectional view showing the present invention applied to an open ended vessel,

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1,

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1,

FIG. 4 is an enlarged view in plan of the roller mechanism,

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4,

FIG. 6 is an enlarged fragmentary view showing the roller and roller actuating screw,

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6,

FIG. 8 is a fragmentary elevational view taken along line 8-3 of FIG. 1,

FIG. 9 is a sectional view partly in elevation showing the present invention applied to a closed end vessel,

partly in section and partly ice FIG. 10 is an enlarged sectional view showing a spider adjusting means shown in FIG. 9,

FIG. 11 is a sectional view taken along line 1111 of FIG. 10,

FIGS. 12-14 are enlarged fragmentary views partly in section and partly in elevation showing the adjustment of the roller so that the axis of the roller is lined up with the helix curve of the path of rolling,

FIG. 15 is a fragmentary tforeshortened view showing a structure for retaining a liner in a shell, and

FIG. 16 is a fragmentary sectional view showing a method of retaining a liner in a shell when the liner cannot be welded directly to the shell.

The present invention comprises a liner applying machine 10 which consists of a olid cylindrical bar 11 mounted in

bearings

12 and 13 at the opposed ends thereof. A drive means 14 rotates the bar 11 through a worm drive gear mechanism 15 positioned in a housing 15a which also houses the bearings 13. A centering spider 16 carries the front bearing 12 and is adjustable to center the bar 11 in the vessel 17. As shown more clearly in FIG. 3, the centering spider 16 includes legs 16a .held in position against the inner surface of the vessel 17 by lock nuts 16b.

A liner applying roller mechanism 18 is rotatably mounted on the bar 11 and comprises a housing 19, and three spaced cylinders 20 connected in series with an accumulator 21 (FIG. 2) by conduits 22, and connected to an outside source of hydraulic fluid H by a conduit 22a. Rotatable rollers 23 are mounted on axles 24 carried by pistons 25 mounted in the cylinders 20. The back side of each piston 25 is connected to an expansi'ble chamber 26 which is connected to the source of hydraulic fluid H through the

conduits

22 and 22a. A half-nut 27 is mounted by suitable means 28 on the housing 19 which supports the cylinders 20, and is threaded on its inner surface to engage a feed screw 29 mounted along the surface of the bar 11 (FIG. 6). A gear 2% is fastened to the end of the :feed screw 29 and is meshed with a gear 29a which is connected to a handle 30 which engages a stop 31 mounted on the "base plate of the device. Therefore, when the bar 11 is rotated, the fixed gear 29a rotates the gear 2% and the screw 29 with respect to the bar 11. Since the housing 19. is keyed to the bar 11, and therefore movable only in a longitudinal direction with respect to the bar 11, the rotation of the bar 11 also rotates the housing 19, and the rotation of the screw 29 drives the housing 19 along the outside of the bar 11.

In applying a lining to a vessel, the lining 32 is constructed to have an outside diameter slightly smaller than the inside diameter of the vessel, i.e., approximately 4;" diameter difference, and positioned within the vessel. The bar 11 is fixed in the vessel 17 by adjusting the spider retainer 16, the outside source of hydraulic power H is connected to the

fluid lines

22 and 22a, and hydraulic power is applied to the pistons 25 through the expansible chamber 26. Normally the mechanism 18 is near an open end of the vessel 17 for convenience. The pistons 25 are moved outwardly into engagement with the inner surface of the liner 32 (FIG. 2) and maintained there by the predetermined and suitable hydraulic pressure applied behind the pistons 25 which may be on the order of 3000 p.s.i. The fluid also passes into the accumulator 21, which is sealed and contains a gas (such as nitrogen). The gas is placed under pressure by the hydraulic fluid and maintains within close limits the proper hydraulic pressure on the pistons 25 regardless of minor variations in diameter of vessel and liner, or expansion or leakage of hydraulic fluid. When the pistons 25 are snfiiciently pressurized, a valve 33 is closed and the fluid pressure source H is disconnected.

A pressure pump could be mounted directly on the mechanism 18 and rotate therewith, if desired.

The motor 14 is energized and rotates the bar 11 through the drive gear 15. The bar 11 rotates the cylinder housing 19 through the keying action of the half-nut 27. As mentioned, the feed screw 29 and gear 29b are connected to a second gear 29a at one end. The handle 36} and stop 31 prevent rotation of the gear 29a'during rotation of the bar 11, and in effect rotate the screw 29 with respect to the bar 11 as the screw 29 also rotates with the bar 11. Since the half-nut 27 also is threaded to the screw 29, as the screw 29 is turned by the gear 2%, the half-nut 27 (and the entire liner applying mechanism 18) are moved along the bar 11 axially. As previously mentioned, the mechanism 18 also rotates with the bar 11, so that the pistons and the roller 23 are rotated around and along the inner surface of the liner 32. This presses the liner 32 outwardly into intimate contact with the inner surface of the vessel 17.

FIGS. 12-14 show a structure for rotating the rollers 23 so that the rollers 23 are aligned with the helix angle of the path of rolling to prevent undue wear on the feed screw 29 or the roller thrust washers. Since the rollers 23 are pressing against up to one-half inch wall thickness in the liner 32, there is tremendous side thrust unless the rollers 23 are rolling along the path of the helix.

The adjustment mechanism comprises a separated rolle-r housing 34 which retains the cylinder 20 and the piston 25. Lock bolts 35 are loosened to enable the cylinder 20 to be rotated with respect to the housing 34. When the proper angle of the roller 23 with respect to the housing 34 is obtained, the bolts 35 are tightened to lock the roller 23 in its new angular position.

FIGS. 9-11 show a modification used when the pressure vessel 17a has a closed end prior to application of the liner 32. In this modification, the gear 29a, handle 30, and stop 31 are positioned adjacent to the end of the vessel 17a at which the drive motor 14 is located.

The principal difference exists in the spider positioning means 36 which supports the end of the bar 11 Within the vessel 17a. The spider 36 supports a bearing 12 for the bar 11 and is adapted to be positioned within the vessel 1711 from the open end of the vessel 17a. The spider is supported by four legs 37 slidably positioned in bore 38 in a spider housing 3'9 and adapted to engage the inner surface of the liner 32 or the vessel 17a. The inner end of each leg 37 is provided with an inclined surface 40 cut at about a angle. Each surface 40 is positioned so as to face the open end of the vessel 17a.

A second bore 41 is formed in the housing 39 at right angles to the first bore 33 and facing the open end of the vessel 17a. A portion of the bore 41 is threaded at 42. A lock cam 43 having a tapered 45 surface 44 is placed in the forward end of the bore 4 1 so that the surface 44 mates with the tapered surface 40 on the leg 37. A longitudinal keyway 45 is positioned in the outer surface of the cam 43 and a key 46 engages the keyway 45 to permit the cam 43 to move only in an axial direction. A screw 47 engages the threaded portion of the bore 42 and may be rotated from the open end of the vessel 17a to move the cam 43 into or out of the bore 41 and to correspondingly move the leg 37 out of or into the bore 38.

The present invention can be used to pro-stress the liner 32 in a circumferential direction, so that when the vessel 17 later is put under pressure in use, the stress in the liner 32 is as close to zero as possible, because the corrosion resistance of the liner 32 is best when it is at zero stress.

It is also possible to pro-stress the liner 32 in a longitudinal direction by anchoring the ends of the liner 32 by the use of welds 48 (FIG. 16). A subsequent rolling of the liner 32 produces longitudinal stretch, since the rolling action tends to lengthen the liner 32 (as much as 4-5 inches in a 15 foot liner). With the ends of the liner 32 contained by the welds 43, the liner 32 cannot stretch and is thus pre-stresscd. When the liner 32 is rolled onto the inner wall of the vessel 17, it is pro-stressed com- 4 pressively in a circumferential direction. Thus in use, under internal pressure, the stresses tend to approach zero in the liner 32.

If the vessel liner 32 is of a reactive material (such as titanium, zircalloy, etc.) which cannot be welded to steel (which normally is the nature of the vessel 17) an end closure such as shown in FIG. 16 may be used to retain the liner 32 in position. In this arrangement, a groove 50 is formed in the end of the vessel 17b and threaded. A liner 3-2 is rolled into position against the inner surface of the vessel 17b. A titanium end ring 51 is threaded into the vessel 17b and a titanium weld 52 is deposited between the end of the liner 32 and the ring 51 to bond the two together. A subsequent application of the liner apparatus will pre-stress the liner 32 in both the circumferential and longitudinal directions.

As mentioned, the present invention can be used in making 'multi-wall vessels and would involve the rolling in of a plurality of liners or vessel walls in a manner similar to that hereinbefore described for applying a single liner to a solid vessel. In accomplishing this, the multi- Wall vessel would have the outer walls pre-stressed in tension and the inner walls pre-stressed in compression so that when the tank is under operating pressure, the stress distribution between the inner and outer layers will tend to be of same order of magnitude. As is well known, the stress in the inner wall rises considerably faster than the stress in the outer wall as the internal pressure of the vessel is increased.

This invention is intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. A method of lining vessels including the steps of positioning a liner in a vessel with clearance between the inner surface of the vessel and the outer surface of the liner, forcing the liner outwardly into contacting relation with the vessel inner wall surface, to prestress the liner in a circumferential direction, anchoring the liner with respect to the vessel in a longitudinal direction after forcing the liner into close contacting relation with the vessel inner Wall surface, and thereafter applying a force to the liner tending to stress said liner in a longitudinal direction.

2. A method of lining vessels including the steps of positioning a liner in a vessel with clearance between the inner surface of the vessel and the outer surface of the liner, and applying a constant force in a helical path circumferentially around the inner surface of the liner from one end of the liner to the other to force the liner outwardly into contacting relation with the inner surface of the vessel, subsequently anchoring the liner against longitudinal movement with respect to the vessel, and again applying a constant force in a helical path circumferentially around the inner surface of the liner from one end of the liner to the other to prestress the liner in both longitudinal and circumferential directions.

3. A method of applying an internal liner to a cylindrical vessel, including the steps of (a) positioning a cylindrical liner in a cylindrical shell 7 with clearance therebetween,

(b) introducing a roller into the liner in spaced relation to the inner surface thereof,

(c) engaging the roller against the liner Wall to urge the Wall outwardly, aligning the roler with the helix angle of the path of rolling and moving the roller along the inner surface without side thrust,

(d) moving the roller in a helical path longitudinally along the inner wall surface to expand the liner into conforming contact with the cylindrical vessel,

(e) anchoring the liner against longitudinal movement with respect to the vessel after the liner has been rolled into engagement with the vessel, and then movingthe roller in a second pass along a helical 5 E path along the inner surface of the liner to pre- 1,944,380 1/1934 Vance. stress the liner in a longitudinal direction. 2,499,630 3/1950 Clark 72113 2,575,938 11/1951 Brenneke 29--523 X References Cited by the Examiner 2,600,800 6/ 1952 P t 1 UNITED STATES PATENTS 5 3,156,042 10/ 1962 Reed- 1472936 10/1923 Anders et CHARLIE T. MOON, Primary Examiner.