US2388177A - Feed-water connection to boiler drum - Google Patents

Description

Oct. 30, 1945. w. s. PATTERSON ET AL I FEED WATER CONNECTION TO BOILER DRUM Filed May 8, 1945 2 Sheets-Sheet l INVENTOR5 Ward ijizl/msan BY Julian tlfiarflzs HTTJRNEY Oct. 30, 1945. w. s. PATTERSON ETAL FEED WATER CONNECTION TO BOILER DRUM Filed May 8, 1943 2 Sheets-Sheet 2 INVENTORS Ward J. Yul/arson BY Julian Liar/mi Patented Oct. 30, 1945 UNITED STATES PATENT OFFICE-Y FEED-WATER coNNEcnoN 'ro BoILER DRUM Ward .8. 'Pattersornlchappaqua, and Julian L.

Barnes; Yonkers, N. Y, assignors to Combustion Engineering Company, Inc., New York,

Application May .8. 1943, Seriai .No. 486,124 8 Claims. (Cl. lea- 365) This invention relates to tubular connections to fluid containing vessels and particularly to improvements in tubular connections thr ugh whic a cold fluid flows into .a. vessel containing a relatively hotter fluid, such as the connection for introducing feed water into the drum containin saturated steam and water in a steam boiler.

It is recognized that where .a tube enters a drum carrying fluid at a di-fieren-t temperature than that within the drum, special :means should be provided to prevent the .direct contact of the tube with the drum shell at its place of entry. For example, where a tube carryingcold liquid is rolled directly into a tube hole in .a drum contaming hot'iiguid the tube temperature would pproach that of the fluid flowing theretlmough while the temperature of the dough at the Joint tends to approach thatof the hotter fluid w i-thin. The. resulting difierences in expansion cause the Joint to leak. With great changes -temper ture injurious internal stresses may o cur within the drum metal near the Joint. For this reason it has also been found desinable to avoid permitting a mass of fluid of a difie ent temperature than that of the drum to directlycontaot the drum in .a l cally restricted area,

n bject of this invention is to provide an improved connection betweena tube and :a vessel each of which is subjectto difierent tempera tures, whereby the metal at the joint is main tained at a substantially uniform. temperature which is substantially equal to that of the vessel by being contacted by a current of fluid of uniform and proper temperature.

In the accompanying drawings: Figures 1 2 3, 3d, 4 and 5 are vertical -.s.ec tional views through the steam and water drum ofa steamboiler, taken on the center line ofatube connection, and represent different forms of the invention. r

Referring first to Figure the steam and water drum 1 of a boiler is provided with .a feed water pipe 2 passing freel into the drum through a SurrOundjng tube 3 iastened to the drum y rolling or weldin into tube hole 4.. Tubes 2 and 3 are preferabl .iastened together by sealing means 5 at a location outside of .andspaced irom the drum. In Figure 2 a third tube fispacedirom tube 3 and fitting closely about p pe 2 is com nested thereto at its inner end ata point to Withi the drum The outer ends of tubes and .6 are fastened and sealed at 6.1). Inb t forms t e feed water nine .2 is surround by an 1 space 1 between it and the tube that is fastened to the druml. V

In Figure 1 a connection 9 is made near the outer end of the annular space between tubes .2 and; for introducing the steam and water mixture discharging from one or more risers ii of a steam generating boiler. The temperature of e steam-water mixture entering through conneotion 9 is substantially equal to that of the steam and water within the drum I so that the water flowin through the annular space 1. be tween tubes 2 and 3 maintain the joint 4 between tube 3 and the drum shell 1 at substantially the temperature of the steam and water within the drum, thereby avoiding the difficulties produced by expansion and temperature stresses.

In Figure 3a the fragmentary longitudinal section shows a multiplicity of' feed water connections 2, 3 like'theone shown in Figure 3 in transverse section; these are arranged in alignment longitudinally of .the drum. To provide a common connection for water at the temperature of the saturated steam Within the drum a space or compartment L0 is formed longitudinally of the drum above a box H below the inner surfac at the top of the shell I, the space It being sealed from the interior of the drum'along its longitudinal and end edges a at l2. One or more connections 9 discharge the steam and water mixture from the generating tubes 8 into the space or compartment 10 above box 1 1 From compartment I u the water flows outwardly into the annularspace 1 between tubes 3 and pipe 2 and thence inwardly through the open end of tube l3 and via the annular space between it and tube 2 discharging into the box II from which the water may be conducted to other apparatus within the drum, such as a steam and Water separator or a steam purifier. In the absence of 'box I] the water would discharge directly into drum 1 from tubes l3.

In Fig. a a compartment I0 similar to that of Fig. 3 is provided but located at the bottom of the drum beneath the water level; This compartment may cover a large sector at the bottom so as to protectjthe bottom locally against cooler ,feed

water coming into contact with the drum shell and the tube joints. The water supply pipe '9 from the steam generating tubes may be provided with a restricted orifice L5 in order to limit the rate of flow, the purpose of which will be explained later. The water from compartment 111 flows downwardly through the annular space '1 around tube It and thence upwardly into the drum through the annular space I 4 between tubes :13 and 2..

In Fig. '5 also the feed .water connection is lodownwardly through the annular space 6 between" tubes 3 and I3 and thence upwardly through the latter at 1 around pipe 2 because of the ejector action of nozzle [6 and Venturi throat I! and mixed with the jet of water from nozzle l6. and discharged therewith through throat 7 l1 and thence into the boiler drum.

The invention is particularly applicable to a forced circulation boiler in which parallel boiler tube circuits are each provided with restricted orifices, or resistances, for the purpose of insuring an adequate flow of water through each and all circuits. In Fig. 1 one of the boiler tube circuits 8 between the circulation pump discharge header and the steam a'ndwater' drum is directed into the annular space between pipe 2 and tube 3.' In Figs; Sand 4 one or more of said circuits 8 are directed into the compartment [0. Should a directly connected tube be provided between the circulation pump and the compartment I0, a restricting orifice or a resistance l5, as shown in Fig. f1, may be introduced into the circuit soas to balance its resistance with that of the remaining boiler tube circuits which discharge directly into the steam and water drum.

What we claim is: v 1. In a vessel containing a heated liquid having an outer. tube fastened to the vessel and open at one end to the interior of the vessel, a tube for supplying a cold liquid to the vessel projecting through the. outer tube and spaced from said outer tube to form an annular passage therebetween and means for fastening and sealing the inner to the outer tube at a point outside of and spaced from the vessel; and pump means for continuously supplying a positive current of liquid at a temperature substantially that'of the liquid in thevessel to said annular passage.

. 2. In a vessel containing a. heated liquid, an outer tube fastened to the vessel and open at one end to the interior of the vessel, a tube for supplying a .cold liquid to the vessel projecting through the outer tube and spaced from said outer tube to form an annularpassage therebetween andmeans for fastening and sealing theinner to the outer tube at a point outside of and spaced from the vessel; a third tube concentrically disposed intermediate the inner and outer tubes and spaced therefrom with one end open thereof ad- 'jacent the seal between said tubes and its other end extending into and open to the drum interior; and pump means for causing a continuous current of liquid of a temperature substantially equal to that of the liquid within said drum to flow positively through the annular passage between the outer and intermediate tubes and thence between the intermediate and inner tubes. a

3. In a vessel containing a heated fluid having an outer tube fastened to the vessel and open at one end to the interior of the vessel, a tube for supplying a cold liquid to the vessel projecting through the outer tube and spaced from said outer tube to form an annular passage therebetween and means for fastening and sealingthe inner to the outer tube at a point outside ofand spaced from' the vessel; a third tube concentri- The boiler water flows cally disposed intermediate the inner and outer tubes and spaced therefrom with one end open thereof adjacent the seal between said tubes and its other end extending into and open to the drum interior; and pump means for continuously causing a positive..currentof the liquid from within the drum to flow through the annular. passage between "the outer and intermediate tubes and thence between the intermediate and inner tubes.

4. In a vessel containing a heated liquid; an outer tube fastened to the vessel and open at one end to the interior of the vessel; partitions within the drumsealed to its walls to form a chamber closed off from the remainder of the vessel; a tube for supplying a cold liquid to the vessel projecting through said chamber and the outer tube. to discharge into said vessel and spaced from said outer tube to form an annular passage therebetween; means for fastening and sealing the inner to the outer tube at a point outside of and spaced from the vessel; a third tube concentrically disposed intermediate the inner and outer tubes and spaced therefrom with one end open thereof adjacent the seal between said tubes and its other end extending through said chamher into and open to the drum interior; a liquid delivery tube connecting into said chamber; and pump means for'continuously causing a positive current of liquid to flow into the chamber to pass thence sequentially through the annular passage between the outer and intermediate tubes and between the intermediate and inner tubesto the interior of the vessel.

5; In a vessel containing a heated fluid having an outer tube fastenedto the vessel and open at one end to the interior of the vessel, a tube for supplying a cold fluid to the vessel rojecting through the outer tube and spaced from said outer tube to form an annular passage therebetween and means for fastening and sealing the inner to the outer tube at a point outside of and spaced from the vessel; a third tube concentrically disposed intermediate the inner and outer tubes and spaced therefrom with one end open thereof adjacent the seal between said tubes and its other end extending into and open'to the drum interior, a portion of said intermediate tube being formed into a Venturi throat; and a nozzle on the end of the inner positioned tube to discharge into the throat whereby a flow of fluid from the drum is induced to flow through the annular Passage between the tubes by the 'jet of fluid from the nozzle.

6. In a vessel containing heated water; a tube connected to the vessel and open at one end to the interior of the vessel, a second tube for supplying cold water to the vessel projecting through the first tube and spaced therefrom to form an annular passage therebetween. and means for fastening and sealing the inner tothe outer tube at a point outside of and spaced from the vessel; and a fluid circulating tube connected to discharge into the annular space between said concentric tubes adjacent the drum. 7

r '7. In a steam and wate drum ofa forced circulation boiler having a pump for circulating the water through steam generating tubes connected for discharge into the drum; a tube for supplying relativelycold water to the vessel projecting through the outer tube and spaced from said outer tube to form an annular passage therebethe drum for positively circulating hot water through said passage.

8. In a vessel containing a heated liquid; partition means extending transversely of the drum near its bottom sealed to its Walls so as to form a chamber closed off from the remainder of the vessel at the bottom thereof; an outer tube connected to the vessel and open at one end to the interior of said chamber; a tube for supplying relatively cold liquid to the vessel projecting 10 through said chamber and the outer tube to discharge into said vessel and spaced from said outer tube to form an annular passage therebetween below said partition; means for fastening and sealing the inner to the outer tube at a point outside of and spaced from the vessel; 2, third WARD s. PATTERSON. JULIAN L. BARNES.

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