US1779941A - Steam boiler - Google Patents

Description

H. J. KE RI R STEAM BOILER Oct. 28-, 1930.

2 Sheets-Sheet l INVENTOR Original Filed June 27, 1924 ATTORNEYS.

Oct. 2s, 1930. KERR 1,779,941

STEAM BOILER Original Filed June 27, 1924 2 sh'eets sheet 2 INVENTOR ATTORNEYS Patented Oct. 1930 UNITED STATES PATENT OFFICE.

HOWARD .TQKERR, OF EL MORA, NEW JERSEY, ASSIGNOR TO THE BAIBGOGK &'WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY srnam 301mm application filed June 27, 1924, Serial No. 722,662. Renewed November 15, 1929.

My present invention relates to devices in which a relatively cool fluid is fed to a chamber containing a hotter fluid, in which it is desirable to mingle the cooler fluid with the 6 hotter fluid in the chamber while maintaining the wall ofthe chamber at approximately the temperature of "the hotter fluid, and

particularly my invention relates to steam boilers of the type in which a tube expanded into a water chamber may be subjected tovariations in temperature at the expanded part relative to the temperature of the water chamber itself.

. My invention will be best understood from the following description and the annexed drawings in which Fig. 1 is aside elevation in more or less diagrammatic form of a boiler to which my invention is applied; Fig. 2' is an enlarged section of a portion of Fig. 1, with some of the parts broken. away; Fig. 3

' is a longitudinal section of one of the tubes and a portion of the drum shown in Fig. 2, and Fig. 4 is a plan view of a detail of Fig. 3. Like reference characters indicate like parts in the several views.

' In the form illustrated, a boiler setting 10 contains a boiler of well-known type, having upper steam and water drums 11, 12 and 13,

connected to a lower drum ltby banks of tubes 15, 16 and 17,- the arrangement described being the well-known Stirling type of boiler.

At the rear of the bank 17 is a bank of tubes 18 constituting an economizer, the tubes 18 being connected to a lower drum 19 having a feed water supply 20*, and the upper ends of the tubes 18 being expanded into the shell of the drum'13. The gases are led in any desired manner across the'banks of'tubes 15, 16, 17 and 18 to the outlet 21.

The arrangement thus far described is old and well-known, and .-a more detailed description thereof will be. unnecessary to those skilled in the art. I

In the type of boiler illustrated, the feed water enters through the feed water supply 2O into the drum 19 and from thence flows upwardly through the tubes 18 into the drum 13, where the feed water mingles with the boiler circulation. While the economizer tubes 18 tend to heat the feed water as it ficiently below the temperature of the shell of the drum 13, so that the expanded portions of'the tubes in the shell of the drum 13 may be contracted sufficiently to permit leakage where the tubes enter the shell.- It will be understood that this leakage arises only be cause of sudden changes because if the change occurred gradually, the temperature of the shell would have sufficient time to adjust itself to approximately that of the tubes cooled by the incoming feed water. The danger of leakage arises primarily from more or less sudden changes in the rate of feeding the feed water supply.

In order to overcome this difliculty, in the illustrative embodiment, I provide a means by which the feed water may enter the drum 13 without contacting thermally with the expanded portions of the tube 18. In other words, I insulate these expanded portions from the incoming feed water so that these expanded portions are not aflected by the temperature or rate of flow of the feed water to such an extent as to affect the joint between the tube 18 and the drum wall.

This insulation maybe obtained in many ways and I have illustrated a preferred form to this end.

In the illustrative embodiment, a plug 19 is rolled or otherwise permanently attached to the interior of each of the tubes '18 and through an axial opening in this plug, thereextends an auxiliary tube 20, this tube 20 being spaced from the interior of the tube 18 and preferably extending, as shown best in Fig. 2, to a point well removed from the interior of the shell 13 and preferably, as shown in Fig. 2, all of the tubes 20 are extended to substantially the same level. While preferably I arrange all of the tubes 18 with the auxiliary tubes 20, it will be understood that this relativel arrangement may be applied, if desired, only to selected tubes, as, for instance, such as are found in practice to give trouble through leakage.

In operation, the relatively cool feed water flows upward through the tube 18 and then through the auxiliar tube 20 and is delivered into the mass 0 water in the drum 13. The .space between the auxiliary tube 20 and the upper end of the tube 18 is in communication with the water space of the drum 13, so that this space is filled with water. The relativel cool feed water flowing out from the end 0 the auxiliary tube 20 might tend to flow directly down the exterior of such auxiliary tube and into the space between the auxiliary tube and the economizer tube, and to prevent this I provide means to divert such water laterall into the mass of water in the drum. In the orm illustrated, such means is provided by a ca 21 on the auxiliary tube 20 which prefera ly will fit .the exterior of such tube snugly and which may be fastened thereto, if desired, such cap having lugs 22 arranged to rest on the top of the tube 18 to provide lateral communication passages communicating with the space between the auxiliary tube 20 and the tube 18. Consequently, the water which flows through the lateral communication passages in the cap 21 is at substantially the, temperature of the entire mass of water in the drum 13.

By delivering all of the water from the economizer tubes well away from the interior of the shell of the drum 13and well toward the center of the drum 13, Iobtain somewhat the same results as are obtained by the use of the well-known feed trough by delivering the cool water from the economizer tubes we 1 into the mass of the water in the drum instead of at points adjacent the shell of the drum as heretofore has been the practice.

The arrangement which I have described is vide a tube and plug arrangement, as shown,

it is obvious that this tube and lug arrangement may be formed in many flerent ways, as, for instance, as an inte al casting and,

indeed, the plug itself may e omitted if the tube 90 were made large enou h at its lower end to be expanded into the tu e 18.

While, preferably, I prevent any of the incoming water from contacting with the oint between the tube 18 and the drum, this is not essential, since obviously some of such incommg water may contact with the joint, provi ed it is not sufiicient in uantity nor temperature to produce such a differential inthe temperature of the parts of the joint as to cause leakage. Thus, itis not essential that the plug 19", or its equivalent, be a water-tight fit in tube 18, provided that the openings thus formed are not large enough to permit a sufiicient quantity of water from the tube 18 to contact with the point where the tube is expanded into the drum to affect the joint.

It will also be understood that while I have shown my invention in connection with a specific type of boiler, my invention may be applied to any type of boiler and will be found useful where the operatin such as I have described. t will also be understood that, while I have illustrated my invention as a plied to a steam boiler to which water is fed: itmay also be applied to any form of device in which a chamber containing a relatively hot fluid of any kind has supplied to it a cooler fluid through a tube entering the chamber and in which the joint between the tube and the chamber, whether an expanded joint or otherwise, might be affected by the difference in ,the temperatures of the two fluids.

It will be understood that in my preferred form, the water from the drum between the tubes 18 and 20 acts as an insulator and that such insulation may be obtained in any other manner, if desired, such, for instance, as the ordinary solid insulating packing which could be inserted in such space or a closed air space formed, provided such insulation is sufficient to prevent sudden changes in temperature in the end of the tube entering the drum which might cause such tube to contract enou h to cause leakage.

I c aim:

1. In a steam boiler, a water chamber, a tube expanded into the wall of said chamber and means to maintain a zone of water from the water chamber against the interior of said tube at its expanded part unmingled with the water flowing through said tube into the water chamber.

2. In a steam boiler, a water chamber, a tube secured in the wall of said chamber, a plug in said tube outside the wall of said water chamber and an auxiliary tube inside said tube and spaced from the walls thereof and carried by said plug and extending conditions are from a point beyond said plug into said water v tube ex anded into the wall of said chamber below t e water level therein, a plug in said tube outside the wall of said water chamber,

no I

and an auxiliary tube inside said tube and spaced from the walls thereof and extending from'a point below said lug into'said water chamber, and means to 'vert water flowing down the exterior of said auxiliary tube from the space between said tube and said auxiliary tube.

5. In a steam boiler, a water chamber, a tube expanded into the wall of said chamber below the water level therein, a plug in said tube outside the wall of said water chamber, and an auxiliary tube inside said tube and spaced from the walls thereof and extending from a point below said plug into said water chamber and a cap member extending over the space between said tube and said auxiliary tube and having lateral openings to form communicationbetween said space I and the water space of said chamber.

6. In a steam boiler, a steam and water drum, economizer tubes entering the lower part of said drum and expanded into the shell thereof, an auxiliary tube in each of said economizer tubes and extending from a point below said shell into said drum, said auxiliary tube being spaced from the interior of its economizer tube at the expanded portion thereof and said auxiliary tube being arranged to conduct the water flowing through said economizer tube into said drum substantially out of thermal contact with said expanded portion.

7 A steam boiler having upper steam and water drums and boiler tubes connected thereto, a bank of economizer tubes entering 1 the lower part of one of said steam and water drums and expanded therein, a-feed water supply connected to the lower ends of said economizer tubes, each of said economizer tubes having means to maintain a zone of water from said upper drum against the interior of said economizer tube at its ex anded portion unmingled with the water sowing upward through said economizer tube.

, HOWARD J. KERR.

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