US2367870A - Steam boiler - Google Patents

Description

Jan. 23, 11945..

INVENTOR V PAUL 1.. .7'05LYN BY 6% ,fijl-li HI. ATTORNEY Patented Jan. 23, 1945 UNITED STATES PATENT oFFioa STEAM-BOILER Pam II. J G'slyn', San firaiibisca; Ap lication-March 18, 1940; Serial'N0.324,'5iP 8Claimsl' (01. 122-41 My invention relates" to a steam generatingunit; and more particularlyto a boiler for engines, turbines; and other machines utilizing steam as a pressure fluidi It isamo'nQthe objects of *Inyinven'tionto pro vide a; boiler for-generating s-team moreefiicientlyto reduce fuel costs.-

Another object isto provide a'boilei by which a givenhead of steam may be obtained more quickly! Another object is to pro-videimproved means for controllingthe rate-of steam generation.

Another object 'is to providea boiler which is safer to operate. 7

Still another object-is tofprovide efiectiveand economical 'me'a ns for sup'erh'eating steam:-

A further object is-toprovidean improvedfeeel Water and -fuel supply-system.

Still further-objects include the provision of a" boiler of the character described which is simple; compact-' and of A less costly design; having" substar-itially' n'owet or scale problems; andembodyin'g an" evaporator unit adaptedforrnultiple usetionof my invention; I It is to be understood that I donotlim it myself to this disclosure of species of my invention, as'I may-adopt variant embodiments thereof within the scopeof the claims.

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Figure 1 is'a vertical sectional view of a boiler embodying theimprovements of my invention;-

and v Figure 2 is a'similar view taken at right angles to the section of Figure li- FigureB-is a fragmentary sectional view of the feed Water nozzle; and

Figure'4 isa de'tail view looking at the inside face of thenozzle head;

Various types of steamgenerating units have been developed in the past, suchas Scotch boilers;

water tube boilers and'flash boilers. These boilers a1l-e1iibody"tubes' and differ 'principally in" whether the latter'conduc'tthe Watertobe evap' orated or the-gase's of combustion; Inea'ch case th boiler operation depends upon a transference of heat through metal tubes to a-bodyof water contained 'either intr'ria-lly or Y externally 'of' the tubes. Such boiler are comparatively 'inefficient thermodynamically: are generally slowin build'-' ing up steam pressure have no meansfor' readily controlling the rate of steam generation; are

relativelyuangerous to'oper'ateahave aggravating 1 cylindrical manor lined 'with're fractorymaterial 3for insulation "and" heat reflection." The lining T Water:

shot and" s'c'ale" problem's: require considerable auxiliary equipment, and ai'ei generally heavy, inflexible and. expensive both toin'stall andoperate: My improved boiler constructionlargely eliminates these problems and-"disadvantages;

Interrns or broao inclusion, my boiler c 'o m prises an evaporating chamber, means for intro}: duc in gfirielydividedfwater into" the chamber, and rr'ieans for heating thechainbe'ri flhe evaporat: ing chamber is preferably'intheformof a rela-" tively small drum disposed directly in' a cornbustion chamber; and is designed for maximum inward radiation" of heat to cause substantially instantaneous" evaporation of the atomized feed A superheatingfchamber is preferably formed as atubular extension of "the main evap; crating portion of the 1 unit, and is arranged to absorb heat from the fluega'ses winsurecom; pl'eteevapor'ati'on "an'd superheatthe steam." This superheater-is'al'so designed for maximum heat absorption by the stea'm; Means alsodisposed to absorbheat from the flue gases is preferably provided for preheating the feed Water. Regu lating means may be provided to control thefe'ed water and'iuel to the furnace; and safety devices may also be" provided "in the system as required."

In greater detailpan'dreferring to Figures 1 and 2 of the drawing,--my boiler comprises a is preferably of sectional structure to 'facilitate' construction and assembly; An inclined 1 bottom 4 "is "pr'ovided fon the casing and is also covered'f Withtlie lining material. A 'plurality ofsajy' three partitions 6 of-refractory material are arranged in the casing'an'd function a's bailies to "divide'the? easing into a lower cornbustionchamber '1 anda series'of upper-flue passege's a'; I Thelower partition has a central opening- 9" While the upper pa'rtitioris'have offset flue open'i ings" H as well as smaller central" openings 12;" The top lining and plate l3 have anape'ituri l4 aligned Withthe "central partition apertures; and also" have an opening I6 coinr'rniriica ting" with smoke stack 11." Openings and Iii are alter nately'dispo'sed on opposite sides or the flue 'pas sages to gi-Ve a' 'zig z'ag' path for" the flue gases; The furnace preferably fired byan oil burner halving ahead"l Tied from'afioirlirie l9; This burner may be of 'any' suitable "construction and further 'details wlll not be given as to the burner" structure per se." The burner i "-'prefer'ab1$i mounted-onaneckportion'- 21 of the casing, dis; posed at' a r-angletdths vertical-axisofftheunit; to 'direct'th'e flameupwardly' into the combustion chamber '1. Bottom 4 is preferably sloped at the same angle.

The evaporating unit of my improved boiler comprises a steam reservoir 22 mounted centraliy on the top of the casing by suitable brackets 23. Depending from this reservoir and supported thereby is a tubular superheating chamber 24 communicating at its upper end with the reservoir and extending downwardly through openings l4 and I2. Tube 24 has a flanged upper end bolted to a saddle flange on the reservoir. Supported at the lower end or tube 24 in Opening 9 is a relatively small drum 26 forming the main evaporting chamber of the unit. This drum has a hanged top neck 21 bolted to the lower flanged end or tube 24 so that drum 26, tube 24 and reservoir 22 are connected as a structurally integral unit, all supported by brackets 23 at the top of the boiler.

Evaporating drum 26 lies principally within combustion chamber l and is disposed to receive the full benefit of the flame from inclined burner head IS. The flue gases in traversing passages 8 envelope the superneating tube or chamber 24, as will be readily appreciated from the construction shown. An important feature to be noted is that tube 24 and drum 26 of the evaporating unit are freely suspended and therefore are free to expand and contract under changing temperature conditions.

lvieans are associated with my evaporating unit for admitting finely divided water into drum 26. For this purpose a pair of nozzles are provided, one at each dished end of the drum, for atomizing the reed water and injecting it into the hot evaporating chamber. As best shown in Figure 4, the nozzle preferably comprises a head 28 held on a studded plate 29 by a cap 3!; the plate being secured to a boss 32 at the end of the drum by studs 33. A pipe 34 feeds water to the nozzle, into a cavity to of the stud, from which the water'flows through outwardly extending passages 37 to a peripheral groove 38 in the face of the stud.

Nozzle head 28 also has a groove 39 in its back face, registering with groove 38 to provide a water channel from which the fluid is. directed inwardly to nozzle orifice 4i through passages 42 disposed tangentially of the orifice bowl. See Figure 4. By this arrangement the water is Well broken up and is given a whirling motion that insures thorough atomization, so that the water is introduced into the evaporating chamber in a finely divided state of subdivision. By changing the size of passages 42 the maximum amount of water admitted by the nozzle may be varied. Arranging the nozzles at the ends of the drum provides two feed water sprays, each directed toward the center of the chamber. While the nozzle structure shown is preferred, it is understood that other suitable types of nozzles may be employed.

Means are also provided for enhancing inward radiation of heat within the evaporating chamber. As shown in Figures 1 and 2, a plurality of radial fins 43 are preferably arranged in the drum to function as heat conductors and provide additional internal radiating surfaces. Baffle means are also provided in the drum and disposed in the path of the projected water particles to give added turbulence and furnish additional heat radiating surfaces. For this purpose a pair of conical plates 44 are arranged circumferentially of the drum adjacent its central portion, the opening between these converging plates leading to the drum outlet through neck 21. A pair of battle plates 46 at the outlet function to further impede the egress of steam from the evaporating chamber,

By this arrangement, the fine particles of water injected into the hot drum are converted substantially instantaneously into steam. This conversion is not only practically instantaneous, but it is also substantially complete. The efliciency of this steam generator is materially greater than boilers heretofore developed, not only because it utilizes heat of radiation as well as that of conduction, but also because the finely divided fluid particles ofier a much larger water surface for heat absorption. In previous boiler constructions where a comparatively large body of water lies adjacent a hot metal surface, the heat transfer is principally by conduction and only the layer of water contiguous to the metal gets the full benefit of the conducted heat. On the other hand, in my steam generator a large water surface per unit volume of fluid is presented to the combined influences of conducted and radiated heat. While a water particle is traveling in a free path in my evaporating chamber it is absorbing radiated heat, and when it strikes a hot surface of the chamber it additionally absorbs heat by conduction. Therefore, when a minute Water particle is injected into the intense heat zone in the evaporating chamber the conversion into steam is substantially instantaneous.

Steam from the main evaporating chamber 26 passes upwardly through super-heating tube 24, wherein means are preferably arranged to provide a tortuous path for the steam and any unevaporated water particles. As shown in Figure 2, a helical strip 41 is disposed in the tube to provide a spiral path for the steam. This strip performs the dual function of a baffle plate and means for amplifying the radiation of heat inwardly of the tube. In addition, helical fins 48 are preferably provided externally of the tube for additionally absorbing heat from the flue gases enveloping it. If desired these fins could simply be annular, radially projecting plates. This arrangement effectively superheats the steam by utilizing flue gas heat that would otherwise be lost, thus adding further to the economy of my unit. From tube 24 the superheated steam passes directly into reservoir 22.

Means also utilizing heat from the flue gases is preferably provided for preheating the feed water. As also shown in Figures 1 and 2, a pipe coil 49 is arranged in one of the flue passages 8. Pipes 34 leading to the atomizing nozzles at the ends of drum 26 depend from the lower convolution of the coil. The temperature of the feed water is thus elevated without requiring an additional source of heat, thereby adding still further to the economy and efflciency of my unit.

Steam from reservoir 22 is led off through a pipe 5| controlled by a suitable valve 52. A safety valve 53 is also provided on the reservoir, along with thermometer 54 and pressure gauge 56 shown in Figure 2. An apertured cover plate 51 on the top of the furnace is disposed under the reservoir to form a seal at opening I4.

It is to be understood that in practice suitable means are also provided for supplying feed water under pressure to the furnace. Further, suitable safety controls may be used as desired. A safety device is indicated at 92 in Fig. 2.

I have described the unitary structure of drum 26, tube 24 and reservoir 22 of the evaporating unit. A feature to be notedin this connection is that the units are readily adapted to be used in multiple to increase boiler capacity. Thus, a series of units may be mounted in a single boiler with their evaporating drums depending into a common combustion chamber. The evaporating units may therefore be standardized as to size, depending upon multiple arrangement for increased capacity. Whether the units are used singly or in multiple, they have the advantage of centralizing the point or points of steam generation, and do not spread over a large area like the tubes of the Scotch or water tube boilers. This centralization provides greater compactness; reduces weight; and requires less fire.

The simplicity and economy of the preheater for the feed water is also to be noted, compared to the multiple stage steam consuming heaters of ordinary boilers. Likewise the absence of soot and scale problems in my boiler eliminates the auxiliary equipment needed to deal with these problems in ordinary boilers where lengthy tubing is present to collect soot, and accumulate scale. The considerable auxiliary equipment required for ordinary boilers often exceeds the cost of the boiler itself, all of which is eliminated by my improved boiler design.

By the terms finely divided water as used throughout the description and claims I mean feed water of particle size that oflers a large surface area for heat absorption yet of sufiicient mass to be projected into all portions of the evaporating chamber against the pressure therein. This may vary from minutely atomized particles t water particles of considerably larger size, depending upon the size of the evaporating chamber, the pressure therein, and the force with which the particles are injected into the chamber.

I claim:

1. A boiler comprising an evaporating chamber, a superheating chamber communicating with the evaporating chamber to receive steam therefrom, atomizing nozzle means for introducing finely divided water into the evaporating chamber, means providing a tortuous path for steam through the superheating chamber, and means for heating said chambers.

2. A boiler comprising an evaporating chamber, a superheating chamber, suspending the evaporating chamber and communicating with the evaporating chamber to receive steam therefrom, means for introducing finely divided water into the evaporating chamber, means for heating said chambers, and heat absorbing fins on the exterior of the superheating chamber.

3. A boiler comprising a combustion chamber having a flue, an evaporating drum disposed in said chamber, a superheating tube leading directly from the drum and extending longitudinally through said flue, a helical baflle in the tube, and means for introducing finely divided water into the drum.

4. A boiler comprising a combustion chamber, an evaporating drum disposed within said chamber, a tube communicating with the drum at a point between the ends of the drum for conducting steam from the drum, atomizing nozzles for introducing finely divided water into the opposite end portions of the drum toward said Point, and burner means in said chamber for heating said drum to cause the finely divided water to almost instantaneously change into steam.

5. A boiler comprising a combustion chamber, an evaporating drum disposed'within said chamber, a tube communicating with the drum at a point between the ends of the drum for conducting steam from the drum, atomizing nozzles for introducing finely divided water into the opposite end portions of the drum toward said point, baflle means on the inner wall of the drum between the nozzles and the point of communication of the tube with the drum for increasing the turbulence of the finely divided Water and presenting heat radiating surfaces in the interior of the drum, and burner means in said chamber for heating said drum to cause the finely divided water to almost instantaneously change into steam.

6. A boiler comprising a, combustion chamber, an evaporating drum disposed within said chamber, a tube communicating with the drum at a point between the ends of the drum for conducting steam from the drum, atomizing nozzles for introducing finely divided water into the opposite end portions of the drum toward said point, frusto-conical b-afile plates on the interior of the drum at opposite sides ofthe point of communication of the tube with the drum, heat radiating fins on the interior of the drum between the ends of the drum and the baflle plates, .and burner means in said chamber for heating said drum to cause the finely divided water to almost instantaneously change into steam,

7. A boiler comprising a combustion chamber having a flue leading upwardly therefrom, an evaporating unit comprising a superheating tube extending downwardly through the flue to be heated by the gases passing therethrough, an evaporating drum suspended from the lower end of said tube to communicate therewith and to be disposed within the combustion chamber, said suspension of the drum permitting free expansion and contraction of both said tube and drum, and nozzle means introducing atomized water into said drum, and burner means in the combustion chamber for heating said drum to convert the atomized water into steam.

8. In a boiler, a casing providing a combustion chamber at its lower portion and a flue at its upper portion, and an evaporating unit comprising a steam reservoir mounted on the top of said casing, a superheating tube depending from the reservoir through said flue, and an evaporating drum carried on the lower end of the tube in said combustion chamber, the drum being suspended from the reservoir by the tube whereby the tube and drum are free to expand and contract as a unit independently of all other parts of the boiler.

- PAUL L. JOSLYN.

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