US2401848A - Water heating and steam generating unit - Google Patents

Description

June 1l, 1946. P. B. WALLACE WATER HEATING AND STEAM GENERATING UNIT .Filed April 21, 19214 IN VEN TOR. PHILIP B. WXLLA as.'

I HTTDR/VE y vPressure steam.

Patented June 11, 1946 UNITED ST1-hres4 PATENT orties WATER HEATING AND STEAM GENERATIN G UNIT Philip B. WallacegSan Francisco, Calif.

Application April 21, 1944, Serial No. 532,041

6 Claims. (Cl. 122-181) -Mypresent invention relates to a heat ex-r l changer device having heat induced convection circulation, andl more particularly relates to a boiler of simple and practical construction for heating water and/or generating steam.

j An object of the invention is to provide a simple and inexpensive water heater or steam generating unit of novel construction which will be particularly applicable to ynon-industrial uses, such as the heating of water for homes, apartments, hotels and the like, or'for generating low vAnother object of the invention is to provide a 'novel boiler which can be constructed almost entirely of cylindrical members of different lengths and diameters and in which the heat is applied in a nove1 and economical manner.

Another object of the invention is to provide an improved heat exchange and baffle arrangement'for water heaters and the like in which the water being heated will be subjected to a reheating circulation by convection.

Another `object of the invention is tok provide a sectionalized water heating and l'steam generating'` unit 'which may-be easily andfconvenientlyl disassembled for a periodic removal of scale vand other foreign particles to the end that a maximum eiliciency will be maintained within the unit at all times.

In vthe construction of hot water heaters and e i.

steam generators of the size and type contemplated by my invention, it has in the past been the custom to construct the various parts of cast iron which may take many complicated shapes and which, because of this fact, is expensive and l diflicult to clean and maintain. It is, therefore"y a further object of my inventionto provide a device which can be constructed entirelyy of wrought -metal 'pipe in a practical and inexpensive manner and which may be periodically disassembled for the removal of scale in a simple and expeditious manner. n

Other objects Vand advantages of the invention will be in part evident to those skilled in the art, and inpart pointed out hereinafter in the following description taken in connection with the accompanying drawing, wherein there is shown by Way of illustration and not of limitation a preferred embodiment of the invention.

Invthe drawing;

Figure 1 is a sectional view taken along the longitudinal center line of a multi-stage Water heating and steam generating unit constructed in accordance with a preferred embodiment of the invention,

and 22 that projectv from the flue II.

Figure 2 is a fragmentary sectionalized view showing a modiiicationA of the device as illustrated in Figure 1 of the drawing, and

Figure 3 illustrates a further modified and sim'- pler form of the'invention for use with a heat conducting flue. A l

In Figure l of `the drawing I have shown a multiple stage 'water heating and/0r steam generating unit constructedin accordancewith my invention and employinga multiplicity of nested and concentrically arranged lengths 'of pipe that arev assembled andvassociated with a v'single hot gas conducting flue in a novel manner. In this arrangement the hot gases used for heating may 'be' taken from any suitable source, or I may em;

ploy a gas or oilburner I0 to provide the hot gases which, as here shown, pass upwardly through a flue I I formed by a length of pipe that has an outwardly extending llange I3 at a'point slightly below its upper enfd, anda second outwardly extending flange I Il nearits lower end. Secured to the underside of the ilange I3 and spaced from the 'flue I I there is a downwardly extendinglength of pipe I5 which carries an inwardly extending flange I 6 that vissecured to the -underside of the flange I4 by means of bolts Il. vThe outer'length of pipe I5 also has a lluid in"- troducing inlet conduit lil'through which a fluid may be introduced into the annular chamber thus formed around the flue II and between the said flue'and thepipe I 5. Positioned vwithin this annular chamber midway between the flue I I and the pipe "I5, and Awith its upper end spaced from the flange I3 there is also an additionallength of pipe I9` that has a plurality of notches or circulation permittingapertures 20 in its lower end through which a fluid may pass from one to the other side thereof. This bane forming 1ength of pipeA I9 is held concentrically between the flue I IV and the pipe rI5 by means of spaced bosses 2| At this point'it should be noted that'the gas or oil burner IG is' positioned within the flue II at a point where the fl-ame therefrom will be applied to the inside of the flue wall at la point above the notched apertures 20 formed in the bottom of the baffle forming pipe I 9 and, as a result, the Iluid in the chamber surrounding the ue I I will be caused to circulate in a vertical direction around the baille forming pipe I9.

The assembly thus far described may be considered to form the first stage of the heater or steam generator shown in Figure 1 of the drawing. As for the second stage of this embodiment of the invention, it will be noted that the outand it has a central aperture through which 'al length of pipe 25 extends. This pipe 26 is supported by an annular collar 21- that is welded'- thereupon which rests upon the hood 23, and at its lower end it is closed, as at 28, so that it'will form an elongated passageway through which the-- water or steam may flow in passing to the dis-l charge outlet. This pipe 26 also in turn supports" an internally disposed length of pipe 29 that exv`.tendsdownwardly to apoint closely, adjacent the bottom or closed vend 28 of the :-pipe 26. f The internally disposed V-length of pipe 2li-has a supporting. flange 30 that is secured by bolts or other 26. The pipe 26 is also here shown yas-provided With-a-discharge outlet A32 through which the -hot water orA steam may be withdrawn from the unit.

-Afcapf 33 nis provided forclosing the upperlend vof the ,pipe 29,and Aimmediatelybelow this' cap 33 there is. an -inletconduit-34 that; istconnected throughfa pipa-35 to' the interior offthe annular chamberformed between vthe ue :i Ira-nd ,the

pipe ,I I5 which, as will` new appear, -forms1 the outerwall or casing of theunit. ,The internally vdisposed'length of'. pipe 29` is here shown as hav- .ing a vseriesof spaced bosses 35 which vserve to Vmaintain it in ,central relation"with respect to the walls of the pipe-ZG-,fandat a; point approachmay .al'so,'if desired, be provided with-.a plurality of.,l spaced apertures 31=that lie inea horizontal Yplane -andfprovide for a'restricted recirculation ofthe waterbyconvectionias thewater. or steam isfxbeing heated. In order to improve the-convection characteristics provided ffor 4bythe aper.- tures13'l, it is Yconteiinplatedthat the lower or closed endf28 of-thegpipezdwill becoveredexL -ternally with Aa- -heat insulating means 38 that ywill prevent A-to some'extent; the direct applica,-

tion ofiheatto .the'outerwalls of `the rpipe'lZIV at a-point-where the relatively-cooler waterv or steam isdischargedfromthe Ylower endl of --thepipe 2 9. 1

Withwthis "arrangement it lwill be .seen' that whenftherflue -II i'sj heated, as described,above,v

and water is admitted through ,the .inletwconduit` I8 and withdrawnL from the Y,outlet conduit 32,v -thel heat-.within the' Vflue vI Lwill be conducted through the-.wallet said huerto-the water in the annular chamber -formedbetween the-flue; and the outer pipe tand, because -of the: baffle I9, this water will be caused to circulate by convection aroundy the baffle in the ymannen-indicated bythe arrows applied to thisgure of the drawing. -Atthe same time, ifwater or steam is beingwithdrawn from the-heater, the waterwill ow upwardly through the pipe-35 and the inlet conduit-34 to the-interior of the internallyfdisposed length of pipe 29 and be discharged `at the lower end thereofl and-into the lower endof the pipe 26. As the water' circulates through this pipe 26, the heat in theV flue II will be. conducted to a thinY film oflwater between-thepipes26 and 29.*a'nd, because of therestricted apertures 31, there willbe formed al 'second convection'circulation of the water as it is being heated. This means toa flangevyl atfthe upperend of thepipe g latter convection circulation will be particularly active in the event that the water or steam is not being withdrawn from the generator at a rate corresponding to the heating thereof. In this operation the water in the outer annular chamber between the pipe I9 and the flue II will be preheated, and in the inner space between the pipes 26 and A29- t will -be Asubjected to a nal heating or Steam` generating operation.

From the above it will be seen that by the arrangement here described, I have provided a 1sirnple,.practical and inexpensive device that is vadapted to heat water and/or generate low pressure steam in an efficient and economical `manner. In the operation of water heaters and Asteam generators it is 'well known that scale and other sediment is precipitated from the water during the heating operation and it is, therefore, also important, if full eciency is to be maintainedin a ydevice of this character, toprovide .means-whereby thev` device1 vmay bey conveniently and effectively cleanedy of thi'sscale andother 4mattenandy to` this end it will benoted that the flue II,.withy its outwardly..extendingwflangesv I3 and ,I4. isf-so constructed.that it may be completely.. removed from the outerg-length ofjpipe I5 vby fanaxial displacement thereof. 1- AtY the A. same time, thebaiileiforming pipe I9l will alsol bey eX- posed insucha manner thatiit, too, Amaybe -readilyscrapedand cleaned of any scale orvother objectionable matter. The pipe 26,with its flange 21,-,is also arranged tobe lifted free oflthefflue .II with thefvented hood 23 so that .itseicterior k surfacemay be cleaned of soot ori.the-like,and.by 35 releasing the flange 30 of the internally disposed length ofrpipe.vl 29, `it will. be possible .to withdraw this latter pipe sothat it-and thegpipe. 2IfcanA be cleaned of-scalerand the like. In ordentopermit this; latter operation, the pipe f 3.5 is shown.. as having a.union 39 fory disconnecting the inlet conduit 34' from the pipe135.v Asfalt auxiliary, the inlet lconduit 34 mayjhave-,a I.-coupling` 4i] from which anY additional `concluitsM rextends,

' either furthe purpose Jof.. introducingfreshwater,

or withdrawinggpreheated wate1directly Yfrom the annular chamber betweenthesfluefftl and tlleouterppipe.` I5. Because of-the` difference: in

the temperature of the flue Hand I'the outer pipe I5, it is possible that there -maynexist some Ldifferential inthe `rate of;expansifm-and/orcontractionrof these members land,= therefore, the outerfxpipe l-isfhere showna-a'srhaving asingle outwardlyextending corrugation 42 that is; adapted to compensate -for ,..anydifference in -rthe Ilexpansion or contraction which may occur.. be-

' tweenthe flue I'I and' pipe I5. Instead of-this corrugation 42, Vit vwill also be lpossibleV to compensateffor :any diiference inY 'expansion or contractionbetween these-parteci the unitbyproviding a corrugated ilue I .,I. In this-latter-event, the corrugations of such auewould-,have additional advantage of providingan increased heat transferring surface with which thewaterin theY outer annular chamber would contact. e

Reference is now made to FigureZ of the-.drawing vwhich illustrates a modication of the -invention that, in other respects, is substantially-identical to the arrangement described above. ,In

1 this arrangement the outer annular-chamber between the iiueY I l and the outer-length of pipe I5 is here shown as sealed at its bottom kby the provision of suitable packingv ringsAS.- that aredisposed between the flanges I4 and I6 carried `respectively by these lengths of pipe.v. fAshere shown, the inner chamber is formed by a length vis rather exposed to the iniiowing fresh cool air,

there will be no necessity `for the heat insulating covering previously referred to as applied to the lower end of thevinner pipe 26. Because of this construction, it willalso be possible to provide the inner pipe 44 with a-,blow-ofl valve 4l that will provide for a periodicdischarge of any sediment which may collect yin the heater at this point. Like the above described arrangement, it will be understood that since the internally disposed length of pipe 46 terminates at a point below the burner 45, there will also be created a difference of temperatures in the water at this point which will tend to set up the desirable convection circulation, which is an important aspect of this invention.

In Figure 3 of the drawing there is shown a more simplified embodiment of the invention. This arrangement is particularly suited to the heating of water in industrial plants where there exists a large amount of excess heat that is generally collected in a large ue which is connected to a more distant stack. In this illustration I have shown only three similar units, designated by the numeral 48, that are arranged so as to extend vertically through a horizontally disposed flue 49. In this arrangement the units 48 are projected through aligned openings in the top and bottom walls of the ilue 49 and they are supported in this position by means of collars 50 that rest upon a top wall 5| of the ue 49. At this point it will be noted that the lower ends of these units 48 are allowed to project downwardly beyond the limits of a lower wall 52 of the flue 49 where they will be exposed to the surrounding air which will be at a considerably lower temperature than the gases in the flue 49. As shown in section at the left of this ligure of the drawing, each of these units 48 is provided with a downwardly extending internally arranged length of pipe 53 which terminates within that portion of the units 48 extending beyond the lower wall 52 of the ue 49. These internally arranged lengths of pipe 53 are also shown as provided with restricted apertures 54 which permit a convection circulation within the water contained in each of these units. At their upper ends these internally disposed pipes 53 are each shown as connected to a water inlet manifold 55, and at the sides of the units 48 and above the Wall 5I of the ilue 49 these units each have an outlet conduit 56 which connects with a hot water pipe or manifold 51. In this way when water is introduced to the units 48 through the pipes 53 from the inlet manifold 55, it will be subjected to heating by the hot gases within the flue 49 and can then be withdrawn through the outlet conduits 55 and the manifold 51 to a point of use. The units 48 are each also here shown as having a removable plug 58 which will permit a removal of any sludge or scale that may accumulate at the bottoms of the units 48.

While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specic devices and arrangements, I desire to have it understood that the invention is not limited to the specific form disclosed, but may be embodied in other ways that will suggest themselves to persons'skilled in the art.i Itis believed that this invention is new andy it is desired yto claim it so that all such changes as come within the scope of the appended claims `are to be considered as part of this invention, 4,

.Having thus described my invention, what I Vclaim and desire to secure by Letters E'atent is: 1. In a fluid heating unit of the character described, the combinationof -a vertically disposed cylindrical pipe having a closed bottom end, ymeans for applying heat to the outside lof, said pipe at apoint above its closed bottom end, and a uid directing conduit forming` a baille extending longitudinally into said rpipe and adapted to discharge a fluid to be heated into ther-interior of said pipe below the pointof'heat application, whereby said iluid will be subjected to a violent convection circulation in said pipe as itis heated.

2. In a fluid heating unit of the character described, the combination of a vertically disposed cylindrical pipe having a closed bottom, means for applying heat to the outer Wall of said pipe at a point above its closed bottom, and a fluid directing cylindrical baille extending longitudinally into said pipe and adapted to direct a iluid to be heated against the inner wall of said pipe below the pointof heat application, whereby the fluid in said pipe will be caused to circulate by convection as it is heated.

3. In a hot water heater of the character described, the combination of a vertically extending flue, a closed relatively long cylindrical pipe suspended within said flue and having a lluid discharge outlet at its upper end, a iluid introducing conduit extending through the top and downwardly to a point closely adjacent the bottom of said pipe, heat insulating means surrounding the lower end of said pipe at the point where the iluid is discharged fromsaid fluid introducing conduit, said fluid introducing conduit also having restricted apertures at its upper end communicating with the interior of said pipe, and means for supplying hot gases to said ue above said heat insulating means, whereby the luid within said pipe will be caused to recirculate by convection as itis heated.

4. In a hot water heater of the character described, the combination with a hot gas conducting llue of, a closed substantially cylindrical pipe suspended within said ue and having a fluid discharge outlet at its upper end, a fluid introducing conduit extending within and throughout substantially the entire length of said pipe and adapted to discharge a fluid to be heated at the bottom thereof, said cylindrical pipe being insulated from the hot gases in said rlue at the point where the uid is discharged from said fluid introducing conduit, and said fluid introducing conduit having restricted recirculation apertures at its upper end communicating with the interior of said cylindrical pipe, whereby the fluid within said pipe will be subjected to a partial recirculation through said uid introducing conduit as it is being heated.

5. In a water heating unit of the character described, the combination of a vertically disposed hot gas conducting flue, a length of pipe positioned concentrically about said flue and supported thereupon at its top and bottom by connecting ilanges to form an outer annular chamber about said flue, a cylindrical baille positioned within, and spaced from the top of and extending substantially the entire. length of said annular chamber and having notches through Vber, and affluidoutlet Stop of salid- Vouter fannular 'char'nb'er' Yand the top 0f' saiduid conducting conduit, a'fluid inlet 'for 'introducing a fluid3 into said outer annular charnat'the top 'of said second length* of pipe, whereby Water Within theunit will be simultan'eouslyv subjected to *a* preheating 'and 'recirculation' AWithin' said annular chambei and :tol al final e'circulatior and heating within said-second 1ength of pipe-by menor, gsepagsa ling through said flue.

scribed, the ycombination of a' htgas enduoting flue, a vertically disposed cylindrical'p'ipe extending into said ue and having 'its bottom end'.- in'- sulated from the hot :gases: in saidffluejwheieby the heat of said hot 'gases' Willbe'applied toi :the outer wall of lsaid pip'e atv a pointabove its Closed :10 bottomn'd, and- @fluid directing oylmdrieal conduit extending longitudinallyV throughfsaid heated into the insulated bottom end'of 'saidr ver'- tically disposed pipe, whereby an improvedfcon- `15 vection circulation Willbeiestablishedwithin 'said pipe as said uid s heated. f Y y f f Y 1 l i" PHILIP B.'WALLACE.

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