US2724370A

US2724370A - steam generating apparatus

Info

Publication number: US2724370A
Authority: US
Publication date: 1955-11-22
Anticipated expiration: 1972-11-22

Description

Nov. 22, 1955 M. H. KUHNER 2,724,370

STEAM GENERATING APPARATUS Filed June 5, 1952 INVENTOR Mnx H. KUHNER ATTORNEY United States Patent Ofiice Patented Nov. 22, 1955 2,724,370 STEAM GENERATING APPARATUS Application June 3, 1952, Serial No. 291,533

3 Claims. (Cl. 122-406) This invention relates to steam generating apparatus and more particularly to apparatus for draining the condensate trough in the steam-and'water drum of a boiler.

In the generation of steam his usual practice to provide means for purifying the steam before passing it intothe superheater. For that purpose certain steam treating apparatus has been placed in the path of the steam as it passes through the steam-and-water drum. One of the principal pieces of apparatus for this purpose is the condenser, an effective type of which is shown in the patent to Andrews 2,424,212 issued July 22, 1947. It has been proposed that this condenser be placed in a trough at one side of the drum, so that the boiler water will be excluded therefrom and so that variation in water level during changes in load will not produce a change in the effective area of the condenser due to the condenser being emersed in varying levels of water, However, one difiiculty encountered in the use of such a trough is that the condensate from the condensers and also from other apparatus such as drier cartons collects in the trough and may accumulate sufiiciently to cover the condensers and thus inhibit their action. The present invention obviates this difficulty in a novel and practical manner.

It is therefore an outstanding object of the present invention to provide, an efiective means for draining condensate from a trough underlying condensers in a steam boiler.

It is a further object of the invention to provide an apparatus for draining the condensate trough of a steamand-water drum which apparatus makes use of the natural circulation of the boiler.

Another object of this invention is the provision of drainage apparatus for use in connection with drum internals which apparatus has a positive action, the activity of which changeswith fluctuation of the load on the boiler.

A still further object of the invention is the provision of a drainage apparatus for drum internals which is simple in construction and which will not be rendered ineffective by chemical deposits, extreme temperatures, and the like.

With the above objects in view, as well as others which will appear as the specification proceeds, the invention comprises the construction, arrangement and combination of parts as now to be fully described and as hereinafter to be specifically claimed, it being understood that the disclosure herein is merely illustrative and intended in no way in a limiting sense, changes in details of construction and arrangement of parts being permissible within the spirit of the invention and the scope of the claims which follow.

The character of the invention, however, may be best understood by reference to certain of its structural forms, as illustrated by the accompanying drawings in which:

Figure 1 is a longitudinal sectional view of a steamand-water drum embodying features of the present invention, and

Figure 2 is a transverse sectional view of a drum embodying the invention, the section being taken on the a line 22 of Figure l and somewhat enlarged.

Referring first to Figure 1, wherein is best shown the general features of the invention, the steam-and-water drum, generally designated by the reference numeral 10, is shown as comprising an elongated tubular section 11 closed at the ends by semi-spherical end members 12 having manholes 13 therein sealed by suitable closures 14. Extending longitudinally of the drum for most of its length is a trough 15 having end walls 16. The trough defines an upwardly-opening enclosure, the opening of which is well above the maximum level of the boiler water. At the ends of the drum are situated downcomer tubes 17. The tubes are of the large type used in high-temperature boilers wherein no heat is absorbed by the downcomers and a minimum number of very large tubes extend from the steam-and-water drum to the lower header or drum, these tubes usually not forming part of the heat-absorbing surface. A drainage conduit 18 enters each end of the trough 15 in the lower portion thereof and extends outwardly and downwardly therefrom. Each conduit 18 ,enters its respective downcomer tube 17 and extends downwardly and concentrically therein. The conduits 18 are somewhat smaller than the tubes 17 and, thus, an annular passage 19 is defined therebetween through which the boiler water flows in its downward passage.

Referring next to Figure 2, which best shows the details of the invention, it can be seen that a feedwater tube 20 enters the drum 10 and is connected to a longitudinal header 21 which lies in the lower portion of the trough 15. A series of condensers 22 extend upwardly from the header 21 in a generally vertical direction. The central tube 23 of each condenser bends downwardly and its end is situated under the minimum water level of the drum. A series of steam-release tubes 24 is arranged around the drum, while steam tubes 25 are connected to the drum in its upper portion and lead to the superheater, not shown. A downwardly-depending separating wall 26 extends from the wall of the drum adjacent the steam tubes 25 and defines, with thelupper portion of the trough 15, a passage 27. A series of drier cartons 28 is supported in the space betweenthe wall of the drum and the separating wall 26. In this view and in Figure 1, it can be observed that the drainage conduit 18 extends downwardly through the downcomer tube 17 to a point below the transition portion where the tube is bent to carry it away from the heat absorption portion of the furnace; this means that the lower end of the drainage tube resides in a straight portion of the downcomer tube. The downcomer tube enters the drum radially and the entrance from the drum into the tube is the same size as the bore of the tube. In the annular space between the entrance and the drainage conduit 18 is inserted a vortex eliminator 30 which consists of at least one tube mounted concentrically of the drainage conduit.

The operation of the apparatus will now be evident from the above description. Feed water enters the system through the tube 20 and fills the header 21. From the header 21 the water flows upwardly through the condenser 22, absorbing heat from the extended surface thereof and then passes downwardly into the lower portion of the drum through the central tube 23. The water passes from the lower part of the drum through the entrance 29 into the downcomer tube 17, passing through the annular passage 19 between the tube and the drainage conduit. While passing through the heat absorbing surfaces of the boiler, the water is converted to steam and the steam enters the drum 10 through the steam-release tubes 24. The steam passes upwardly and enters the passage 27 between the separating wall 26 and the upper portion of the trough 15. It then passes over the condensers 22 where a portion is condensed and most of the impurities are removed; the condensate. sirens into the lower nor-- tion of the trough 15. The .stearn then passes upwardly through the drier cartons 28 on the other side of the separating wall 26, llhCuCfi-HOHS removing droplets en-. trained in flow. Droplets collected by the cartons drop downwardly into .the trough also. It is necessary to remove the condensate from the trough 15 more rapidly than would be possible by natural flow through the drainage conduits 18; this is done by use of the aspirator effect of the flowof the boiler water in the downcomer tube past the open lower end of the drainage conduit. The flow .of water from the drum into the .downcomer tube is restricted :to a more or less linear flow by the vortex eliminator .30. Such straightfline flow will produce the optimum suction on the drainage tube and will prevent other troubles that may arise because of the swirling that would otherwise be present.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is:

l. A steam generati-ngapparatus, comprising: a steam andr-water drum, a series of condensers for treating steam passing thereover, said condensers extending vertically within the range of possible levels of the water in the drunna trough underlying and partially surrounding the said series, a downcomer tube connected to the lower portion of .said drum, a drainage conduit connected to the lower portion of said trough and entering the downcomer tube substantially coaxially therewith, and a vortex eliminator situated in the entrance of the downcomer tube into the drum, the vortex eliminator consisting of at least one tubular member supported coaxially with the rainage conduit.

2. A steam generating apparatus, comprising: an elongated, tubular steam=and-water drum, steam-release tubes entering said drum, steam tubes leaving said drum, a series of steam treating condensers lying in the path of the steam as it proceeds from the steam-release tubes to the steam tubes, the condensers being of tubular construction to carry incoming feed water internally thereof for the indirect condensation of steam on the exterior thereof, the Condensers having extended exterior surfaces, said condensers extending vertically within the range of possible levels of the water in the drum, a trough extending longitudinally of the drum and underlying the said series water level in the drum, .a downcomer tube connected radially to the lower portion of said drum, a drainage conduit connected to the lower portion of said trough and extending into the downcomer tube a considerable distance coaxially therewith, and a vortex eliminator situated in the entrance of the downcomer tube.

3. A steam generating apparatus, comprising: an elongated, tubular steam-and-water drum, steam-release tubes entering said drum, steam tubes leaving said drum, a series of vertical steam-treating condensers aligned side by side longitudinally of the drum lying in the path of the steam as it proceeds transversely of the drum from the steamrelease tubes to the steam tubes, the condensers being of tubular construction to carry incoming feed water intersaid series 10 a height well above the maximum possible nally thereof for the indirect condensation of steam on the exterior thereof, the condensers having extended exterior surfaces, said condensers extending vertically within the range of possible levels of the water in the drum, a trough extending longitudinally of the drum, and underlying the said series of condensers, the trough extending upwardly around the said series to a height well above the possible waterlevel in the drum, a downcorner tube connected radially to the lower portion of said drum, a drainage conduit connected to the'lower portion of said trough extending into the downcomer tube a considerable distance coaxially therewith, and a vortex eliminator consisting of at least one tubular member situated in the entrance of the downcomer tube, said eliminator being supported coaxially of the said tube.

' Refer nces C te the fil of this patent UNITED STATES PATENTS,

OTHER REFERENCE Riley Condenser Steam Power Purifier, Sept. 1950.