US2024572A

US2024572A - Return bend

Info

Publication number: US2024572A
Application number: US666651A
Authority: US
Inventors: John E Getzen
Original assignee: FRED C FANTZ
Current assignee: FRED C FANTZ
Priority date: 1933-04-18
Filing date: 1933-04-18
Publication date: 1935-12-17
Anticipated expiration: 1952-12-17

Description

Dec. 17, 1935. J. E. GETZEN 2,024,572

' RETURN BEND Filed April 18, 1933 2 Sheets-Sheet 1 FIG. I.

Fla-5.

Dec. 17, 1935.

J. E. GETZEN 2,024,572

RETURN BEND Filed April 18, 1953' 2 Sheets-Sheet 2 NEY Patented Dec. 17, 1935 UNITED STATES PATENT QFFICE RETURN BEND- John E. Getzen, Birmingham, Ala., assignor to Fred C. Fantz, Webster Groves, Mo.

' Application'April 18, 1933, Serial No. 666,651

Claims. (Cl. 285-29) My invention relates to that class of return bends which are employed in the cracking coils or tube nests of cracking plants in refineries. It is well known that in the operation of cracking that coke deposits on the inside of the. tubes and that this coke, if permitted to accumulate, is

highly dangerous as it tends to cause fires which result in damage to property, loss of time caused by the shut down of the still due to the fire, and sometimes to very great loss of life.

Because of this condition it is necessary to remove the accumulated coke from the interior of the still tubes. This is accomplished by opening the ends of the tubes and inserting a rotary tube cleaner which cuts out the coke from the inside of the tube until the tube is bright. In standard practice this is accomplished by means of what is called an H shaped header box or return bend which is provided with threaded plugs which are 29, screwed into the header box. These plugs must be unscrewed to permit the insertion of the-rotary tube cleaner. Great difficulty is experienced with these plugs 1 as they frequently cannot be removed even when as many as five or six men 5 are placed on theend of a 5 foot wrench and they haveto be burned out with an acetylene torch.

.If one plug sticks, it means that the still must stay shut down until repairs are made.

It is well known in the industry that the down time is far more expensive than the cost of repairs or replacements. Therefore everything that can possibly be done, is done to shorten the down time of a still. As a consequence it has lately 5 become the practice to employ a removable return bend which is fitted to the ends of the tubes fit and which is mounted in a housing provided with toggles to hold the return bend tightly against the ends of the tubes forming a leak-proof joint. By 49 removing these togglesthe U bend can be removed and the rotary tube cleaners inserted in the tube.

It also frequently happens in the operation of a refinery that it becomes necessary to remove a tube from the still coil or bank and with the 4.5 standard practice it was generally necessary to destroy a perfectly good tube by cutting it ofi in order to remove the defective one. As a consequence there has been a growing practice lately to employ a demountable tube in which the tube 50 is upset with a shoulder and sectional metal rings are mounted intermediate the shoulder and annular portions of the housing which encircle the tubes. In this way the tube can be demountably 55 tion or replacement at will.

My present invention has for its object to provide a construction which will avoid the necessity of using the sectional metal bushing and at the same time will provide an improved manner of holding the housing sections together. The 5 means usually employed for this purpose require some sort of extraneous devices such as bolts, etc., to hold them in position. My improved invention provides for a, construction which will of itself hold the securing means in place when the return bend assembly is ready for operation.

My means of accomplishing the foregoing objects may be more readily understood by having reference to the accompanying drawings which are hereunto annexed and are a part of this specification, in which- Fig. l is a side elevation of a. return bend constructed in accordance with my improvement, one-half of it being shown in section, so as to show the interior construction;

Fig. 2 is a bottom view of the same;

Fig. 3 is an end elevation of the return bend fitting, all of the parts being assembled in position;

Fig. 4 is an end elevation of the housing section showing the manner of removing them from the means for holding them together; and

Fig. 5 is a bottom view of the housing section as shown in Fig. 4.

Similar reference numerals refer to similar parts throughout the entire description. As shown in the drawings, a conventional U or return bend l, is mounted upon the ends of still tubes 2 and 3 so as to provide a continuous passageway therethrough. The ends of the tubes 2 and Bare upset forming shoulders i. As the construction for mounting the tubes is identical I shall only describe one of them.

The housingis formed, as illustrated, in two sections, each of which is provided with two semicircular portions adapted to encircle one-half of 40 the tubes 2 and 3. The

semi-circular portions

5 and 6 are provided with extensions 1 and 8, the inner surface of which forms shoulders 9 which are adapted to engage the shoulders 4 and formed by the upsetting of the tubes 2 and 3. The housing is provided with upwardly extending side walls It] and H. Slots it are formed in the upwardly extending side wall and in these slots are mounted toggles l3 which'carry set screws is, the inner ends of which engage abutments i5 formed on the 5 external wall of the return bend l.

The sides l6 and H of the extensions 1 and 8 are milled ofi, as very clearly seen in Fig. 2. The meeting or adjacent faces l8 and [9 of the extensions l and 8 cut away asclearly seen in Fig. 3.

These extensions 1 and 8 are each provided with a peripheral bead and 2|. Around the extensions and 8 I mount an annular member 22, the purpose of which is to hold the sections firmly together when in assembled position.

The device is assembled in the following manner: The annular member 22 is passed over the ends of the tubes 2 and 3 and the sections of the housing are then placed so that the arcuate shoulders 9 are below the shoulders 4 formed on the ends of the tube. The housing is then swung into the position shown in full lines in Fig. 4, the cutaway portions l8 and [9 of the faces of the extensions 1 and 8 permitting this movement. When in this position, the annular member can be moved up and over the extensions 1 and 8. The housing sections are then swung into the position shown in full lines in Fig. 3 and the annular member 22 serves to hold them tightly together. It will be apparent from the foregoing description that it would be impossible to pass the extensions with the bead 2i! and 2| formed on their periphery through the ring if the extensions 1 and 8 were complete semi-circles at their periphery. I therefore provide for milling off the sides as shown in Fig. 2 until they are cut away sufi'iciently so as to clear the inside of the ring or annular member 22. This is very clearly seen in Fig. 5, an inspection of which shows that when the housing sections are in the position shown in full lines in Fig. 4 they have ample clearance to pass through the interior of the annular member 22.

It will be apparent from the foregoing that by this construction I provide very secure and rigid means for holding the housing sections together. Yet when the housing sections are removed the retaining ring 22 will only drop on the tube until it strikes the tube sheet where it will be in position for use when the housing is to be replaced.

Although I have described separate rings it will be obvious to persons skilled in the art that these rings may, if necessary, or desired, be connected without departing from the scope of my invention.

Having described my invention what I regard as new and desire to secure by Letters Patent is:

1. In a refinery apparatus, a conventional return bend adapted to connect a pair of shouldered tubes to provide a continuous passageway therethrough, a housing for said return bend comprising mating sections each having inwardly extending arcuate shoulders adapted to engage said tubes to meet the shoulders thereon, extensions on said sections which partially surround said tubes, annular members which surround said extensions and hold said sections in position, means on said extensions to hold said annular members in place, the adjacent faces of said extensions being cut away, and means mounted in said sections to force the return bend and tubes into a leakproof joint.

2. In a refinery apparatus, a conventional return bend adapted to connect a pair of shouldered tubes to provide a continuous passageway therethrough, a housing for said return bend comprising mating sections each having inwardly extending arcuate shoulders adapted to engage said tubes to meet the shoulders thereon, extensions on said sections which partially surround said tubes, annular members which surround said extensions and hold said sections in position, a peripheral bead formed on each of said extensions which said annular member abuts, the adjacent faces of said extensions being cut away, and means mounted in said sections to force the return bend and tubes into a leak-proof joint.

3. In a refinery apparatus, a conventional return bend adapted to connect a pair of shouldered tubes to provide a continuous passageway therethrough, a housing for said return bend comprising mating sections each having inwardly extending arcuate shoulders adapted to engage said tubes to meet the shoulders thereon, extensions on said sections which partially surround said tubes, annular members which surround said extensions and hold said sections in position, means on said extensions to hold said annular members in place, means mounted in said sections to force the return bend and tubes into a leak-proof joint, the sides of said extensions at right angles to their meeting edges being milled away.

4. In a refinery apparatus, a conventional return bend adapted to connect a pair of shouldered tubes to provide a continuous passageway therethrough, a housing for said return bend comprising mating sections each having inwardly extending arcuate shoulders adapted to engage said tubes to meet the shoulders thereon, extensions on said sections which partially surround said tubes, annular members which surround said extensions and hold said sections in position, a peripheral bead formed on each of said extensions which said annular member abuts, the adjacent faces of said extensions being cut away, means mounted in said sections to force the return bend and tubes into a leak-proof joint, the sides of said extensions at right angles to their meeting edges being milled away.

5. In a refinery apparatus, a conventional return bend adapted to connect a pair of shouldered tubes to provide a continuous passageway therethrough, a two part housing for said return bend each part having two upwardly extending side walls, a web formed integral with said walls which connects them, said housing comprising mating sections, each having inwardly extending arcuate shoulders adapted to engage each of said tubes to meet the shoulders thereon, extensions on said sections which partially surround said tubes, annular members mounted on said sections to hold said shoulders in engagement with said tubes, means formed on said extensions to hold said annular members in place, detachable means mounted in said upwardly extending side walls to force the return bend and tubes into a leak proof joint, the abutting faces of said extensions being cut away to permit the mounting of said annular 'means thereon.

JOHN E. GETZEN.