US3149412A - Tube puller - Google Patents

Description

Sept. 22, 1964 R. L. CURFMAN ETAL 3,149,412

' TUBE FULLER Filed June 22, 1962 j 2 Sheets-Sheet 1 INVENTORS Ronald L. Gurfman Robert 14 Just P 1964 R. L. CURFMAN ETAL 3,149,412

TUBE FULLER 2 Sheets-Sheet 2 Filed June 22, 1962 INVENTORS N Qul Ronald L. 6urfman Haber! W. Just United States Patent 3,149,412 TUBE FULLER Ronald Locke Curfman and Robert W. Just, Mandan, N. Dak., assignors to Standard Oil Company, Chicago, 111., a corporation of Indiana Filed June 22, 1962, Ser. No. 294,320 1 Claim. (Cl. 29-202) This invention relates to an apparatus for sliding tubes and rods relative to a supporting assembly. In particular, the present invention relates to an apparatus for pulling heat exchanger tubes from a tube sheet of a heat exchanger.

In the petroleum refining industry, heat exchangers are commonly constructed with a plurality of tubes mounted tightly in the tube holes of a tube sheet. When servicing the heat exchanger, broken or worn tubes must be removed. Since each end of the heat exchanger tube is rolled tightly into a tube hole in the tube sheet, it cannot be removed from the heat exchanger by hand. Various devices, generically known as tube spears, are commercially available for spear-ing the tube to initiate its removal from the tube sheet. Such tube spears generally spear the heat exchanger tube from the inside and remove it several inches fi'om the face of the tube sheet. An example of a tube spear is shown in US. 2,951,- 282. Once the tube is pulled several inches from the face of the tube sheet, a powerful pulling means is necessary to complete the removal of the tube. It is current in the petroleum refining industry to complete the tubes removal by attaching a winch or fork-lift truck to pull the tube from the tube sheet. This method entails the use of unnecessary men and expensive equipment. The apparatus of the present invention is a light-weight, inexpensive tool particularly adapted for rapidly completing the removal of heat exchanger tubes from a tube sheet.

Accordingly, an object of this invention is to provide an effective, inexpensive apparatus for pulling heat exchanger tubes from a tube sheet. And to overcome a more particular problem of the prior art, the present invention furnishes a light-weight tool for removing heat exchanger tubes, which may be operated by one man. A further object is to provide an apparatus suitable for pulling linear members such as, tubes and rods relative to a stationary support. Other objects, such as the removal of rods from packings, will become obvious to those skilled in the art upon examination of the detailed description of this invention.

Broadly, in accordance with the invention, the above objects are achieved by an apparatus comprising a housing, two shaft members mounted within the housing, at least two substantially opposed Wheel members arranged to frictionally engage between their peripheries a rod or tube, a drive means and gear means for operatively connecting the drive means to at least one of the wheel members.

More specifically, the invention includes a housing having a plate at the rear of said housing for abutting against the face of the tube sheet. Mounted within the housing are substantially parallel shaft members. The shafts are provided with front and rear bearing supports. Rigidly mounted on each shaft is a wheel member. The wheel members are substantially opposed and each wheel member has a concave serrated periphery adapted to frictionally engage a tube between the peripheries of the wheels. In a preferred embodiment, the lower shaft member is pivotally supported to permit pivotal movement of the lower wheel member. The pivotal movement of the lower wheel increases the distance between the wheel members and allows easy access of the rod or tube to be pulled. Both wheel members exert a driving force on the tube to be removed. Intermeshing gears connect the rotatable shaft members, to have both wheel members exert a driving force on the tube. Gear reduction means transmit force from the motor to one of the rotatable shafts. A 1.4 HR, p.s.i.-390 rpm. airdriven motor has been found to be an effective drive means.

A clear understanding of the novel apparatus of our invention is obtained by reference to the drawings.

FIGURE 1 is an elevational view of the apparatus in a working position on the face of the tube sheet of a heat exchanger. A part of the gears are broken away to more clearly show the operation of the apparatus.

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1. FIGURE 2 illustrates the relationship of the driving means and the lower shaft wheel assembly.

FIGURE 3 is a sectional view along line 33 of FIGURE 1, taken through the center of both shaft wheel assemblies.

With reference to FIGURE 1, a housing 1 provides support for the apparatus and has a flat plate In for abutting against the tube sheet 12. The shaft members 2 and 3 are rotatably mounted on the housing 1, and are supported by bearings. On shaft 3 a Wheel 4 is rigidly mounted. A second wheel 5 is rigidly mounted on shaft 2 and is substantially opposed to wheel 4. On shafts 2 and 3 are regidly mounted intermeshing gears 6 and 7. A drive means, in this case an air motor 8, drives the lower shaft 3. The lower shaft 3 and wheel 4 are pivotally supported on an eccentric pivot bolt 9. Wheel 4 and shaft 3 can thus be pivoted away from the tube sheet to allow easy insertion of the tube 11 between the wheels 4 and 5.

When the peripheries of the wheels 4 and 5 frictionally engage the tube 11 and power is applied to the wheels the plate 1a abuts against the tube sheet 12 holding the apparatus stationary.

Now referring to FIGURE 2; the drive shaft 13 of the air motor 8 is secured to the worm gear 16 by way of the pin 14. The gear 17 is rigidly mounted on shaft 3 and the shaft is supported by a rear bearing 18 and a front bearing 19. Wheel 4 is fixed upon shaft 3 and is provided with a concave serrated periphery 21. A gear 7 is rigidly mounted on the shaft 3. The drive means 8 and the shaft 3 are supported by the plate 1a.

FIGURE 3 shows the opposed wheel members 4 and 5 engaging a tube 11 on their concave peripheral faces 29 and 21. The gears 7 and 6 intermesh and are rigidly supported on the shafts 3 and 2. Shaft 2 is supported by a front bearingl 22 and a rear bearing 23. Rotational power is transmitted to shaft 3 by the rigidly mounted gear 17 from gear 16 on the drive shaft 13 of the m0- tor 8. The rotational movement of shaft 3 is transmitted to shaft 2 through the intermeshing gears 7 and 6. As the shaft members 2 and 3 rotate a driving force is exerted on the tube 11 by the rigidly mounted wheel members 4 and 5.

The lower shaft 3, bearing supports 18 and 19, wheel 4 and gear 7 are pivotally supported on the eccentric pivot bolt 9. By pivoting the shaft wheel assembly forward around the pivot bolt 9 the tube 11 may be easily inserted and removed from between the wheels 4 and 5. When a driving force is exerted on wheels 4 and 5 and the wheel 4 is brought into contact with the tube 11, the driving force will tend to pivot wheel 4 backwards so as to tightly engage the tube 11 between the wheels 4 and 5.

In its preferred embodiment the apparatus of this invention operates in the following manner. The heat exchanger tube is removed from the tube sheet several inches by means of a tube spear. The apparatus is lifted to the tube sheet, and the tube inserted between the peripheries of the Wheel members. To facilitate handling the apparatus it may be suspended from the top of the heat exchanger by a Winch and easily manipulated by one man. When both Wheel members are brought into frictional contact with the tube, and a driving force applied to a wheel member, the wheels will exert a force normal to the tube. The apparatus will move along the tube until it abuts against the tube sheet. The rotational movement of the wheels will then pull the tube from the tube sheet.

The force exerted by the wheel members upon the tube is insuflicient to deform the tube. However, to maximize the friction between the tube and the wheels, without exerting a force sufiicient to deform the tube, the radius of the peripheral face of the wheels should approximate that of the tube. By varying the diameter of the wheel members, tubes of ditferent diameters may be removed without crushing and deforming the tubes.

Tests of the apparatus of the present invention have shown it to be an effective and highly efiicient means for removing tubes from heat exchangers. Its simple operation permits one man to accomplish a task which formerly required several men and heavy equipment. It can be seen from the description that we have provided a novel and useful apparatus for removing tubes from a heat exchanger and for removing other linear members from their supporting assembly.

Having described our invention what we claim is:

A tube puller for remoivng heat exchanger tubes from a tube sheet which comprises in combination: a housing comprising an abutting portion adapted to abut against said tube sheet, support means, and bearing means; a first shaft member having an end portion and an intermediate portion thereof journaled in bearing means fixedly mounted on a first movable support means pivotally connected with a second support means fixedly mounted on said abutting portion; a second shaft member having an end portion and an intermediate portion thereof journaled in bearing means fixedly mounted on said abutting portion, said second shaft member positioned paralled to said first shaft member; a first gear member and a second gear member, each gear member rigidly mounted on and positioned to intermesh at the non-journaled end of each of said shaft members; a first Wheel member and a second Wheel member, each wheel member being rigidly mounted in opposed relationship on said shaft members and positioned on said shaft members between said hearing means at the intermediate portion of said shaft members and said gear members at the non-journaled end of said shaft members, said wheel members having concave and serrated peripheral faces for frictionally engaging a tube between their peripheries; a drive transmitting means fixedly mounted on said first shaft member and positioned between said bearing means for said first shaft member; and a drive means fixedly mounted on said first support means and drivingly connected to said drive transmitting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,387,944 Price Aug. 16, 1921 2,433,477 Quinn et al Dec. 30, 1947 2,820,607 Dawes I Jan. 21, 1958 3,042,373 Berkman July 3, 1962

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