US1752331A - Return bend - Google Patents

Description

F. c. FANTZ ,7 ,33

RETURN BEND April 1,1930.

Filed April 5, 1929 5 Sheets-Sheet 1 INVENTOR.

FRED C. FANTZ A TTORNEY5 April 1, 1930. c, FANTZ 1,752,331

RETURN BEND Filed April 5, 1929 5 Sheets-Sheet 2 c. FANTZ CZ) K ATTORNEYS April 1, 1930. c TZ I 1,752,331

RETURN BEND Filed April 5, 1929 3 Sheets-Sheet 3 i -EJ ATTORNEYS Patented Apr. 1, 1,930"

rann'c. rnrrz, o'r wnnsrnn enovns, mrssounr RETURN BEND Application filed April 5, 1929. Serial No. 852,780.

My invention relates to that class of return bends designed to connect tubes which have been nested in banks to form heating coils and the like, for hydrocarbon stills, crackingstills, or similar structures, where the oil is heated to high temperature and is under very high pressure. A i

It is well known that, due to the high temperature and pressure in tubular stills of the type mentioned, the life of the tubes is comparatively short. Itis also known that the tubes have to be cleaned out, owing to the fact that as the oil passes through the heated tubes a considerable deposit of free carbon attaches itself to the inner walls of the tubes, andtends to increase greatly the frictional resistanceof the passage of the oil through the tubes. When this carbon deposit becomes too thick to permit free circulation of the i oil, it is necessary forthe still to be shut down and the carbon removed. This is done by removing the return bend from the ends of the tubes, and passing a tube cleaner through the tubes.

'85 It is also known thatif one of the tubes in a. bend has been destroyed by the heat, the

other tube has to be cut oil, usually by an acetylene torch, to get the return bend olf.

This results in the total loss ofthe tube thus 80 cut. The short ends then remaining have to be chiseled out of the return bend, and this must be done without injuring the bend, otherwise it also is destroyed. Furthermore, where the tube is expanded inside the return bend, as is frequently done, the tube must be rolled while it is cold. This prevents the use of allo ,s for heat-resisting tubes, as they are so brittlethat they resist rolling.- This is true of most tubes which are impregnated, or coated, with an alloy, because any rolh'ng will crack and destroy the coating; consequently under such circumstances it is practically impossible to use corrosion-resisting alloys. Where the tubes are made of alloys, the return bend must also be made of the same, else the expansion will be different and a tight joint cannot be obtained.

As these bends necessarily have to be very heavy in order to sustain'the extremelyhigh can be readily cast out of an alloy without ex-.

temperature and pressure, they are very expensive when made of any of the numerous heat-resisting alloys. a

My invention has for its object, to provide a construction whereby any tube may be removed for examination or replacement,,without removing or. destroying any other tube,

and without any danger of injury to the re-- turn bend.

One great advantage of my return bend is that the tubes can be rolled or. forged in the shop before they are placed in the bank; this permits the use of heat-resisting alloys, if desired.

Another advantage of my return bend is 05 that it can be quickly and easily-removedto permit the cleaning of the tubes; and it is so small, in comparison with the usual type of bend employed for this purpose, that it cessive cost, and therefore, when weakened by corrosion, it can be thrown away, as the expense of replacement would be negligible.

Thetubes frequently bow with heat. With my improved construction, tubes can be turned over at any time, thus equalizing the deteriorating effect of theheat upon them, and thereby greatly increasing the life of the tubes in the bank.

' Moreover, by providing for the speedy re-. moval of the bend, easy and frequentinspection of the tubes is also provided for, thus greatly lessening the danger of explosion due to tubes which have become weakened in use. v

In addition to the foregoing .advantages,

my bend can be used with a flanged pipe on tube, and no operation is required to fit the tube to the bend.

My means of accomplishing the foregoing object may be more readily understood by having reference to theaccompanying drawings, which are hereto annexed and made a part of this specification, in which- Fig. 1 is a disassembled view of my return bend and the yoke; I r Fig. 2 is an end view of the return bend in assembled position; 3 v I 1 ig; '3 is a side elevation, partly broken mo away to show the interior construction of the bend; I

Fig. 4 is a top or plan view of the device as shown in Fig. 3, the movable plate being omitted from the right hand end thereof;

. Fig. 5 is a plan view of my construction,

. plate; and Y Fig. 9 is a plan view of the sectional bushgimilar reference numerals refer to similar parts throughout the entire description.

In the drawings, only fragmentary portions of tubes 1 and 2 are shown, as obviously these form no part of my invention, for it will appear from the hereinafter contained description that any type of tube may be used with my bend, with equal facility. I shall only describe the connection ofthe bend to tube 2, it being understood that the connection to tube 1 is identical. f As shown in the drawings, the end 3 of tube 2 is expanded outwardly, forming a shoulder 4. A metal bushing 5, which is ring-shaped, and is formed in sections to facilitate its mounting upon the tube '2, is mounted intermediate the outside of the tube 2 and the inside of an annular portion 7 formed on a yoke 6, and engages the shoulder 4. The yoke 6 may be formed in a single piece as shown, or it may be formed in two pieces if desired, as shown in Figs. 5 to 7. The annular portions 7 of the-yoke 6 have upwardly extending segmental side walls 8 and 9. Slots 10 are formed in the inner surface of the side walls 8 and 9, adjacent their upper ends 11 and 12. The return bend 13 has cast or formed on its exterior wall two abutments 14, each of which is adapted to be en-' gaged by the end 15 of a set screw 16, which is mounted in a movable plate 17, which is provided with two radially extending arms and is adapted to receive the end of the ex-. panded portion 3 of the pipe or tube 2, though it will appear from the hereinafter contained description that it is not necessary to construct the return bend so as to have the groove to receive the end of the pipe or tube, as it will be obvious to persons skilled in the art that the pipe or tube might be flanged and simply engage a gasket of copper or other suitable material placed intermediate the faces of the return bend and the pipe or tube, 'or might simply abut a smooth face having a gasket interposed.

7 In assembling the device, tubes 1 and 2 are placed in the nest or bank; the annular portions 7 of the yoke 6 are passed over the ends of the tubes 1 and 2; the sections of the bushing 5 are then placed intermediate the outer wall of the tubes 1 and 2 and the inner surface of the annular portions 70f the yoke 6;the return bend 13 is then placed inside the yoke 6, with the annular grooves 20 engaging the ends 3 of the-pipes or tubes 1 and 2; the movable plates 17 are then placed so that the arms 18 and 19 extend intothe spaces between the side walls 8 and 9; then, by adj usting the movable plates 17 so that the arms 18 and 19 register with the slots 10 in the side so walls 8 and 9, and then tightening up the. set screws 16, it will be obvious that the annular members 7 of the yoke 6 will be drawn upwardly, and in turn the bushings 5 will be caused to tightly engage the shoulders 4 5 on the ends 3 of the tubes 1 and 2. This will at the same time, as clearly seen from the sectional view in Fig. 3, press the return bend 13 downtightly upon the tubes 1 and 2.

For additional strengthening purposes, it to may be found desirable to cast or forge a web 21 to connect the side walls 8 and 9, as clearly shown in the drawings.

Where an elbow is required, it will be .ap-

parent, from an inspection of the structure as shown in Figs. 5 to 7 inclusive, that. the only thing necessary to do is to form a flange 22' upon the elbow 23, the lower part of the elbow 23 corresponding preciselyto that portion of the return bend 13 shown in section in Fig.

3, and the method of clamping to the pipe or tube being identical in both cases.

It will be apparent, from the foregoing description, that the return bend when thus constructed can be very quickly and easily removed from the tubes. ,Moreover, the portion of the return bend which is subjected to intensive action of heat is quite small and light, as compared with the clamping portion of "the device, and since the parts are 11o easily separable from each other, the return bend can be replaced many times without porhaving to replace the heavier clamping tion of my device.

Furthermore, it is obvious that one would never have to cut off the end of a tube, nor

to chisel it out of the return bend, since it is not inserted 1n the bend save for the. slight contact in the annular grooves 20; but since it is well known that while coking offers a very great resistance to sliding movement, the coke possesses practically no tensile strength, and consequently I have found in practice that the bend will drop free from the tube with a comparatively slight blow a hammer, regardless of the length of time it hasbeen used, nor how great the accumulation of coke.

When one desires to remove the tube 2, by sliding the yoke 6 down on the tube 2 it bevention within the scope of the claims,

comes easily possible to remove the sections of the bushing 5, when the yoke 6 can be removed from the expanded portion of the tube 2, and there is then nothing to prevent the tube 2"from being rotated in the-bank, if bound, or withdrawn if desired. It will also be obvious that should one of the tubes become so corroded that it needs replacement, there will be no necessity for losing the adjoining tube. I

For the purpose of full disclosure of my invention, I have described in some detail a specific embodiment thereof; but it will be apparent that numerous changes might be made in the physical embodiment of my inand I do not desire, therefore, to be understood as limiting myself, in the broader aspects of my I invention, to the specific construction shown and described.

Having described my invention, what I re-' gard as new, and desire to secure by Letters Patent of the United States, is:

1. The combination with a pair of tubes the ends of which are upset to form external shoulders, of a return bend, a housing there for comprising annular portions, which en-' circle the ends of said tubes, upwardly extending side walls on said annular portions, webs which connect said side walls and said annular portions, internal shoulders-on said annular portions, sectional shouldered bush ings intermediate said annular portions and said tubes which abut the shoulders on the annular portions and the tubes, means detachably mounted on said side walls, set screws in said means which engage said return bend whereby the tightening of the screws will force the face of the return bend tightly against the ends of the tubes.

' 2. The combination with a pair of tubes the ends of which are upset to form external shoulders, of a return bend, a housing therefor comprising annular portions which encircle the ends of said tubes, upwardly extending side walls on said annular portions, webs which connect said side walls and annular portions, internal shoulders on said annular portions, sectional bushings intermediate said tubes and said annular portions, said bushings being provided with means to abut the shoulders on the annular portions and the tubes, there being slotsformed in said sidewalls adjacent to their upper ends, movable plates fitted to said slots, set screws in said plates the inner ends of which engage said return bend. I I

3. The combination with .a pair of tubes the ends of which are outwardly expanded, a

return bend, a housin therefor comprising I annular portions whic encircle the ends of said tubes, upwardly extending side walls on saidannular portions, webs which connect said side walls and annular portions, internal shoulders on said annular portions, secwalls to on the annular portions and the outwardly expanded ends of the tubes, means detachably secured to said side walls, to force the face of the return bend tightly against the ends of the tubes.

4. The combination with a pair of tubes the ends of which are upset to form external shoulders, of a return bend, a housing therefor comprising annular portions which encircle the ends of said tubes, upwardly extending side walls on said annular portions, webs which connect said side walls and annular portions, internal shoulders onsaid annular portions, sectional bushings intermediate said tubes and said annular portions, said bushings being provided with means to abut the shoulders on the annular portions and the tubes, means detachably secured to said side force the face of the return bend tightly against the ends of the tubes.

5. The combination with a pair of tubes the ends of which are upset to form external shoulders, of a return bend, there bein annular grooves in the face of the return end which fit'the ends of the tubes, a housing therefor comprising annular portions which encircle theends of said tubes, upwardly extending side walls on said annular portions, webs which connect said side walls and annular portions, internal shoulders on said annular portions, sectional bushings intermediate said tubes and said annular portions, said bushings being provided with means to abut the shoulders on the annular portions and the tubes, there being slots formed in said side walls adjacent to their upper ends, movable plates fitted to said slots, set screws in said plates the inner ends of which engage said return bend. I

6. A connection for tubes for oil stills comprising a return bend, a housing therefor hav- I ing annular portions formed thereon adapted to encircle the ends of a pair of tubes, upwardly extending side walls on said annular portions, means detachably' secured to said side walls adjacent their tops and set screws mounted in said means, webs which connect said side walls and said annular portions,

FRED C. FAN TZ.

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