US2000907A - Superheater assembly - Google Patents

Description

May 14, 1935. c. s; TURNER v SUPERHEATER ASSEMBLY I Original Filed Feb. 1, 19.32 2 Sheet-Sheet 1 INVENIOR [fi yzgs 6) ATTORNEYS May 14, 1935. Q 5 URNE SUPERHEATEB ASSEMBLY Original Filed Feb. 1, 1952 ZIS I'we tS-Sheet 2 Zara/56a) Charles S. 72153 ATTORNEYS Patented May 14, 1935 UNITED STATES 2,000,907 suraanmm ASSEMBLY Charles s. Turner, Detroit, Mich.

Applicationl ebruary 1, 1932, Serlal No. 590,1 Renewed October 6, 1934 .7 Claims. (01. 122-473) of which a bank or group of superheater tubes may be installed in positions ofmaximum radiant heat exposure, with their terminal fittings or connections adequately protected against a degree of heat, which, under frequently encountered operating conditions, would cause the rapid deterioration thereof, while 'the superheater tubes themselves will, because of their special and pre-" ferred construction, last an indefinitely longer time without noticeable impairment.

These terminal fittings, which are usually of cast, one-piece construction, are of-course designed to handle, receptively at one end of their respective superheated tubes and distributively at the other end thereof, not only the supply of steam whose superheating is desired, but as well the cooling fluid column whose surrounding walls are generally integrated with the wall of the superheater tube proper, and, if the superheater units are, as well, equipped with integrated cleaning or blower jet pipes, the cooling influence of the fluids passing through one or both ofthese is suflicient to protectively influence the temperature of the superheater tube walls against unduly rapid heat impairment.

This, for the reasons above stated, not being the case as to the generally cast terminal flttingsof the several superheater tubes, particularlyif either the cooling column or the sootblower elements are not active, special protective constructions for these terminal fittings become necessary. My. preferred construction for eifecting this illustrated in the accompanying drawings, wherein Figure l is an'elevation'al view, partly in sec tion, of a tubular boiler installation equipped as well with my superheater protective elements.

Figure 2 is a plan view from above, showing a plurality of superheater tubes in their extent across the flue space in a furnace chamber, and emphasizing the positioning of the, terminal flttings of the superheater tubes behind both the baflles and whatever number of boiler tubes it may be desired to position them.

Figure 3 is an elevational view, partly in section showing the end fittings of a superheater tube protected at one end, as in Figure 1 behind a baifle and plurality of boiler tubes, and at the other .end by a wall of the furnace, through which the other end of the superheater tube extends Figure 4 is a sectional view illustration of a preferred form of construction of companionterminal fittings for the superheater tubes, whose protection against undue and destructive thermal conditions is desired.

Figure 5 is a longitudinal sectional view of the preferredform of terminal fitting shown cross- I sectionally in Figure 4, along the line 5-5 thereof.

A represents the walls of the furnace, over whose central heat flue space B are obliquely positioned boiler tube elements C. For purposes of guidance of the gases of combustion through suc- 10 ces'sive tube banks, the boiler drums as G, baflles D, which generally are immediately behind one or more of the boiler tubes as C; are positioned on either side, as shown, forming in effect a more or less constricted throat about the flue space B. 15 For superheating purposes, a plurality of superheater tubes, as E and F, are positioned angularly, though much more nearly in a horizontal position than the boiler tubes C, across the flue space B, ofcourse. much nearer the heat source 20 than the boiler tubes C, and directly in the path of the upwardly proceeding heat units. Each of this series of superheater tubes E or F, cooperatively with its corresponding supply tube as E and F, of course are components of a ,U-shaped 25 circulatory system, and the advantage of having each superheater" tube lying at an angle to the horizon as shown lies in the fact that each leg of the circulatory system as thus constituted does its share in contributing toward eifective circulation,-each superheater tube constituting the hot leg of the U-shaped structure, while its connected feeder or supply tube constitutes the cold leg; 4 without such an arrangement, that is to say, if the superheater tubes'were positioned horizontal- 1y across the flue space B, the action of some: such element as agpump would be necessary to keep up an adequate degree of circulation, aswell as to determine the direction 01' circulation.

This alteration of the superheater tubes of 40 the series E and F is brought out with special clearness in plan Figure 2, wherein it will also be noted that inthe showings of the terminal flttingsL and N the upper or right-hand ends of the several superheater elements E have their steam supply tubes E shown in full lines and the superheater elements of the series F similarly have their steam supply tubes F shown in full lines, the position, on the lower side of the fltting of either series of its corresponding steam 5 discharge pipe being indicated by dotted circles at E and F respectively; these latter elements are of course shown elevationally in full lines in Figure 1.

As stated, and as brought out particularly in u cross-sectional Figure 4, these superheater tube units have, in addition to the space J through which the superheated steam passes, an integrated cooling column, as K, which of course extends lengthwise of the superheater tube structure superheater tubes of the series E or F in Figure 1.

Though of course there may be as many super-' heater tubes T as may be desired, or the depth of the furnace chamber may permit, they are not alternated, as in the instance of the first described construction because 01 their being but one bank or inclined boiler tubes; and all of the superheater tubes T extend in the same oblique direction. The lower end of each superheater tube T of this series now being described extends relatively close assemblage by the receiving fitting, as L, while the fitting N, at the other end of the superheater tube, effects the distribution of the fluid elements respectively handled by the several guiding columns to their respective piping connections appurtenant to the furnace as a whole. Cooling .water connections, generally with a common supply pipe for all of the superheater units, are shown at M.

The separate chambers J and K of each ter- 7 radiant heat action to the same degree as the superheater tubes E or F themselves. If, however, one or both of these auxiliary, heat-modifying appurtenances are. not functioning, as is fretubes, as C, is of such markedly lower tempera-' ture, even with the furnace working at capacity, that with the terminal fittings, as L and N, positioned thus, they in most cases attain only a temperature which at the worst is much more slowly destructive of the fittings than would be the case ii',they were, like the superheater tubes,exposecl to direct'radiant heat. In most cases the positioning of the terminal fittings behind the baiiles and behind the first or outer row of ordinary boiler tubes, as C, is-generally sufiicient for the adequate protection of the terminal fittings L and N, but in case unusually high heat conditions are through the verticaLfurnace wall W, so that this latter protects the lower terminal fitting, as V, against undue heating just as the baffle S, and the s veral rows of boiler tubes Q protects the upper erminal fitting X. The steamsupply and outlet connections of the terminal fittings are the same as already .described in connectio with the explanation of Figure 1. I

What I claim isz 1-. In a furnace having baiile' walls, in combination with a plurality of spacedly disposed banks of boiler tubes flanking an intermediate space between said baille walls through which rising heat units and gases of combustion travel, a fluid-cooled superheater element extending across said space and inclined from the horizontal, having separate steam and water passages therein and metallic heat bridging portions connecting and integral'with the walls of each, inlet and outlet terminals connecting said passages with the steam and water spaces respectively of the boiler, the water inlet terminal thereof being positioned below the water outlet terminal, whereby a convection current is induced in the water channel of the superheater element, and both the inlets and outlets being located outside said intermediate space and baflle walls.

2. Incombination with a furnace having baifle wallsand an intermediate flue gas passage, a I

said passage, water-cooled superheated tube as-' semblies extending laterally across said passage between opposite units of each tube group and inclined from the horizontal, separate steam and water channels in each of such tube assemblies and having walls, metallic heat bridges integral with and connecting the walls;a water inlet in the lower end of each assembly, and a water outlet at its higher end, said inlets and outlets being arranged outside said bafllle walls and intermeto be dealt with, a still further degree of protection can be secured by positioning the fittings L and N behind the second row of ordinary boiler tubes, as C, or even further back as for example, behind the still more remote tube rows as C? and C. In any event, and according to the particular circumstances of each case, a marked heat. dif-.

ferential between the thermal conditions to which the superheater tubes, as E and F, are intention-- ally exposed, and those to which the terminal fittings L and N, often unprotected by cooling colhere shown positioned behind a plurality of the boiler tube rows, and between the units of these rows and protectedlythrough the baflie S extend the superheatertubes 'I with their terminal fittings V and X in the same oblique position as the diate passage. I

3. In combination with a furnace incorporating steam generating means and having a combustion chamber, superheating means comprising steam and water conduit portions arranged closely appurtenant one'another and extending across the combustion chamber at an angle to the horizontal, integral heat bridging portions connecting 4. In a steam boiler, in combination with a water conduit portions arranged adjacent one I another and extending across: said passage at an angle to the horizontal, integral heat bridging portions connectingsaidsteam-and water conduit portions, said conduits being extended through said walls, and inlet-and outlet portions conected to the 9,000,907 5. In combination with a steam boiierhsving walls deiining'a passage thro l which heated gases of combustion pass, regulatable steam superheating' means comprising separate metallic steam and water conduits extending across said passage at an angle relatively to the horizontal and in close proximity, and integral metallic heat brid ing portions connecting said steam and water conduits. 3

6. In combination with a steam boiler having walls defining a passage through which heated gases 0! combustion pass, regulatable steam superheating means comprising separate metallic steam and water conduits extending across said e at an angle relatively to the horizon and in close proximity; and metallic heat bridging means-extending substantially the length of the eiiective portions of said conduits and integral with both the steam and water conduit portions.

7. Incombination withasteamboilerhaving walls defining a e through which heated gases of combustion pass. regulatable steam super-heating means comprising separate metallic steam and water conduits extending across said passage at an amle relatively to the horizon and in close proximity to each other, metallic heat bridging portions extending substantially the entire effective length 01' said conduits and integral with both the steam and water conduit portions, said conduit portions being projected through the walls, and inlet and outlet portions connected to said conduit portions outside the walls.

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