US1903970A - Superheater arrangement for cylindrical shell boilers - Google Patents

Description

`April 18, 1933 w. H, ARMAcosT SUPERHEATER ARRANGEMENT FOR CYLINDRICAL SHELL BOILERS Filed April 25, 1932 2 Sheets-Sheet 1 :NVE T R Willow Xfmwst BY Q KM ATTORN EY Apri11s,193s., w H ARMACOST 1,903,970

SUPERHEATER ARRANGEMENT FOR GYLINDRICAL SHELL BOILERS Filed April 25, 1932 2 Sheets-Sheet 2 o@ fn oo 0000330000 lNVENTOR Wi l bur H. Ananas? ATTORNEY Patented Apr. 18, 1933 UNITED WILBUR H.ARMAGOST, 0F NEW Yon-x; N. Y., AssIGNoR To THE SPERHEATER 00M; e

PANY, oF NEW YQRK, N. Y. ,n 1

Appliaton mea April 25, 1932.', semina. 607,334.

A number of superheater arrangements have' been proposedfor boilers of the Cylindrical drum type having one or more return fire-tubes and the lire-box beneath and outside the drum. The prior superheater arrangements for such boilers have either developed excessive metal temperatures when the boiler` is being forced Vor have required a" relatively large amount of tube surface to produce the desired degree of superheat. Many of such arrangements,- moreover, have been diiii'cult to apply to a boiler which may have' been installed without a superhea-ter. `A

It is the principal object of my invention to provide al superheaterarrangement' for eit'ernally fired drumtype fire-tube boilers which shallavoid theabove mentioned diff fioul-ties.

The novel featuresy of my invention are pointed out in the appended claims. odenhowever, that the invention, together withfits objects and advantages, may bel more clearly understood, II will new describe in detail and in connection'withy the accompanyingAr drawings several arrangements of boiler andi superheater selected by1 way of example' from among a number of possible embodimentsof my invention. Inlthe drawings,-

Fig. l is an elevational view of a horizontal return tube boiler' having! a superheater inaccordanc'efwith my inventionr applied thereto. Y

Figf2- isA av section on theVl line 2-'2 of Fig.

1, looking inthe direction of the arrows.,

Ffig. 2Agis' a detailfplan View of oneof the turnbuckles appearing in Fig. 1'. A i

l-igwlis a fragmentary view offal boiler similar tothat of Fig. 1 andihaving'a modiied form of superheater associated therewith. 1 v

Fig'. t is afvertic'alv sectional view on the linef off Fig. 5,'y of anotherY form of Aboile'rbut'having a' s'uperheater in accordance with my invention' associated there-V vWith.

Fig.' 5 is an elevationaltview of the" apparatus: shown'in Fig. 4. l v

Referrin'glmore particularlyto Figs. l" and 2, -10 is a boiler Yhaving a horizontal shell 11 of cylindrical form and having-a furnace chamber 12 and a lire door 14 at the front end'of the boiler setting; Heating gases from furnace 12 pass rearwardly from the -f'u'rnace beneaththe shell 1'1 to the rear e-nd thereof and' thence vpass thrux one or more fire tubeswithin the shell 11 to a' breeohing le at its'front end and thence out thru stack 161 As appears in Fig. 2,y boiler 10 has' a large number of comparatively small fire tubes 18, 18, but I do not limit myself to this.`

ln'aocordan'ce' with oneform of my inven'- tion, the superheater 20` is'placedonthe outside of the boiler shell' somewhat to the rear v ofthe furnace 12. Superheater 20 comprises a number of units 22,'22, ea'ch'of whichfis'bent tothe same' con-tour as' the external surface A of the'she'll 11'. In'the'arrangement"shown7 steam passes'from boiler 10 thru a' pipe'24 to lends itself however toa'm'ethod'of supportsv ing the superheater whereby its positioncan f be very conveniently'adjusted. In the ar'- rangenient shownfcurvedrods v32, 32 are coni neeted toheaders 26 and28 at pointsf, 34

v and run upwardly paralllfto the surface'of Y the shell'll to pointsatthetopof such'shell wherey the rods 32fp`ass' thru t'urnbuckles 36, 361. one of turnbuekles 36 isiillustrafed in detail infFig'. 3." Rodsl 32-are`threaded'at' their ends andv eziteiidfthru: and beyond the turnbu'c'lles so that nuts 38,'f38'on therods "32 can be adjusted' t'on'ot only cause'rods32 to supporti the 'superheater 20 on shell l1 but also Vto determine the'v distance of* the elements 22 from the' outer surfaee ofl the boiler' shell.

By changing the distance" between the ele:- m'ents'22 and the'drum, thetenperature of 'the steamdelivere'd from the superheater' at a givenloadlonthe boiler will` be varied'du'eto the fact thatV the counter radiation from l`the elements 22 to the water cooled shell 11 varies with such distance.

Preferably the headers 26 and 28 lie slightly above the horizontal central plane of the boiler so that they may be installed in an existing boiler plant with a minimum disturbance of the setting. The ordinary horizontal return tubular boiler has a setting which in-V cludes side walls 40, 40 and the boiler shell has brackets 42,42 fixed thereto which trans-Y fer the weight of the boiler to side walls 40 at a level approximately that of the horizontal central plane of the shell. Therefore, a superheater in accordance with my invention can be adapted to an existing installation merely by tearing out two smallV holes in the setting on each side.' After the headers and units have been putin place, such holes can be easily patched up with a minimum amount of labor.

Another advantage of bendingthe units 22 to the same contour as that ofthe boiler drum is that it makes it possible, when there is very little clearance, to install such units by first placing them in an inverted position over the top of the boiler and then sliding them around the drum. V

The arrangement shown in Fig. 3 is the same as that in Figs. 1 and 2 except lthat the superheater units 22a are not all of the same length, some having a greater radius of curvature than others. As shown, the unit nearest the fire-box has the shortest radius and lies nearest the boiler shell 11, and those progressively farther from the fire-box are progressively longer and lie farther away from the shell 11, so that elements22a, as shown, shield each only slightly from the gas flow. The arrangement of 3 therefore is well adapted to produce a'highdegree of superheat. Moreover, the` unit 22a which is farthest from the furnace being also farthest fromvthe shell 11, the metal and thevseveral Vunits 22a are at nearly the same temperature.

In the arrangement of Figs.4 and 5, the boiler 10a has a cylindrical shell portion 11a beneath which is a furnace chamber 12a. .At the rear of furnace 12a boiler 10a has a shell portion 11b having an oval cross-section, and within which is a group of fire tubes 18a for conducting hot gases from furnace 12a to a smoke chamber 42 at the rear of boiler 10a. From chamber12a, the gases flow thru tubes `1,8 to a breeohing 14 at the front ofthe boiler.

In the arrangement illustrated in Figs. 4 and 5, thesuperheater lies beneath the-boiler section 11a!l and above the lire-chamber 12a. The superheater elements 22 are preferably of exactly the same type as those illustrated in Fig.V 1, but owing to their location, the superheater of Figs. 4 and 5 has a partly radiant characteristic. If desired, the superheater elements 22 of Figs. 4 and 5 may be p-laced adjacent the front wall of furnace chamber 12a to thereby produce a superheater having almost an entirely radiant characteristic.

It will be seen that the superheaters 20 have their units 22 connected to headers 26 and 28 in two parallel rows so that alternate units have their ends bent out away from the drum and into the same transverse plane as one of the other units. connect into headers 26 and 28 respectively at the ends of the latter. Furthermore, the drawings show the units 22 as connected to the headers 26 and 28 by disconnectable joints. It will be understood', however, that I do not limit myself to any of these features.

It will be evident also that the adjustment of superheater units toward or away from the generating surface of the boiler as to which they lie in radiating relationshipnecessarily affects the iinal steam temperature.

I find that4 a material change. may bemade 646,071, filed December 7 1932, for superheater with adjustable counterradiation.

It is evident further that the balljoints shown between the superheater'units and headers are adapted to permit the -units to be swung somewhat in their seats andthat lsuch swinging oryadjustment may be used to move the units clos/er together or farther apart to therebyV vary the effective heating surface of the superheater. However, the

units illustrated herein happen to be of such 'form that the resulting change is small and I have not claimed such feature in this application, but have so done in my co-pending application Ser. N o. 653,254, filed January 24, 1983, for superheater boiler in which the units have a different contour.v

What I claim isz,

1. The combination with a boiler having a horizontal cylindrical shell portion, of means for passing heating gases along th elower outer surface of said portion,and a superheater having tubes running beneath said portion from side to side thereof and'each substantially parallel to its outer surface.

2. The combination as set forth in claim 1 and in which the tubes of the superheater are arranged in a single layer.

3. The combination as set forth in claim 1 together with headers for the superheater tubes arranged on a plane abovethe horizon'- tal plane thru the centre of the boiler.

4. The combination with a boiler having a horizontal cylindrical shell portion, of means for passing heating gases along the lower outer surface of said-portion,and a Also, pipes 24 and 30I superheater having tubes running beneath said portion from side to side thereof and each substantially parallel to its o`uter surface but having said tubes progressively farther Jfrom said-shell in the direction of flow of the heating gases.

In testimony Whereofl aHX my signature.

VILBUR H. ARMACOST.

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