US1683972A - Steepled radiant-heat steam boiler - Google Patents

Description

Se t. 11, 1928.. 1,683,972

- C. G. HAWLEY STEEPLED RADIANT HEAT STEAM BOILER Fild llarc h 12, 1924 2 Sheets-Sheet 2 Sept. 11, 1928.

Filed March 12, 1924 2 Sheets-Sheet 1 l l I O I I I U G Patented Sept. 11, 1928.

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Application filed mm; 12, 1924. Serial no. 688,728;-

This invention relates to improvements in steam boilers and furnaces; and comprising an especially desirable and novel high pressure steam boiler of the type first disclosed in my co-pending application Ser. No. 6&3,- 731, which has since become U. S. Patent No. 1,486,888, issued March 18, 1924... The specific purpose of this application is to patent certain modified forms and structures which could not be specifically claimed in said patent for the reason that another specific form had been selected to be claimedtherein. 7

In bmmon with the parent invention the objects of the present-invention are toharmonize the best conditions for the substantially smokeless combustion of long flaming fuels with the best conditions for the highly eflicient transmission of the heat to the boiler water, including a rapid circulation of thelatter; and generally to increase the capacity and efliciency of such boilers, to relativel reduce their size and their cost, to make tliem safer, simpler to maintain more durable, and, more quickly and certainly responsive to varying furnace tem-' peratures and rates of combustion.

With these and other objects in view my invention provides a boiler with an under lying combustion chamber or furnace space of a height that permits the flames of such fuel to rise to substantially complete maturity before the gases leave the combustion chamber, thus enabling a most complete and efiicient burning of the fuel at any desired rate; and concurrently, my invention 1nsure-s an eflicient and maximum transmission of heat to the boiler water through the'medium of a minimum number of boiler heating elements of surfaces and'wit-hout resort to abnormally high furnace temperatures, this" dividing perform being accomplished by operatively1 the boiler into'twosections whic substantially distinct duties, the first sectlon directly absorbing the radiant heat of combustion within the combustion chamber and comprising complementary boiler elements which are within said' chamber and are of such limited number, form and arran ement as to' greatly subdivide the body 0 flame and present considerable surfaces thereto and yet avoid' premature extinguishment of the flames, while the other section of the boiler is devoted to the absorption of the heat of the combusted and non-fiaminggases from the combustion chamber. 7

In conformity with such conception the heating elements which are located within the combustion chamber are of limited numher and small area and yet are full adequate to the absorption of substantia ly all of the radiant heat of the fire. By acceptng the greater part of the heat in this state, 1t becomes possible to secure an increased efiiclency and steaming capacity or without loss of efficiency to greatly reduce the total heating area of the boiler as compared with present boilers and the quantity of fuel burned.'

As will resently appear the action of the water an steam in the radiant heat absorblng elements causes a definite and rapid circulation of the water throughout the boiler; not' alone in the radiant heat absorbin elements but also upon all of those boller surfaces which are devoted to the absorption of heat by;convection; thus raising the efliciency of those surfaces and making it possible to relatively reduce the extent thereof, or to secure a greater quantity of steam therefrom. The active circulation of the boiler water incidentally enhances the durability of the whole boiler and lessens the maintenance cost thereof.

It should now be evident that my invention takes advantage of the fact that in relation to a given heat absorbing surface, radiant heat is many times more available and efiective than the heat of non'luminous hotgases; the heat of flamin gases transmitted in conformity wit the laws of light, while actual surface contact is essential to the transfer of heat from merely hot ases. I f

When such precautions are taken against cooling the burning gases by contact with cold surfaces, the heat radiated bythe flame ing gases 'is accepted by adjacent boiler surfaces without materially reducing the temperature of the flame and without interrupting the chemical-combination and self-1gnition'of'thecontinually sup lied combustibles. Thus it appears that y my invention the greater part of the heat available in'the fuel may be transmitted to the boiler water through radiant heatt absorbing elements or watercourses of relatively small extent; leaving the conservation of the rebeing a steam therefrom.

sidual heat of combustion to be performed by the more extensive supplen'lentary surfaces of the boiler. The foregoing statement concerning the virtual non-reduction of flametemperature is not to be confused with the reduction of the flame-body, which of course diminishes toward the top; that is, as the combustion proceeds to maturity The gases derived from a substantially complete combustion, such as here'indicated creased; again making it possible, compara-' tively, to reduce the total heat absorbing area thereof or conversely to secure more The foregoing statements are applicable to long-flaming fuels of all kinds and hence I here call attention to a feature of my invention which has a special relation to ashcontaining fuels. It appears that by my invention it becomes possible to fully utilize the heat of many such fuels while working the furnace at temperatures effectively below the fusing or slagging point of the fuel ash. Asby this method it is feasible to do so Without detriment to the described sustained combustion, I advise as standard procedure the provision of slightly more absorbing surface within the confines .of the combustion chamber than actually required. for

the absorption of all the radiant heat of the fire. The computation follows Well-known rules; the cost of .the additional surface is negligible; and, the superabundant surface becomes a substitute-forthe shortened time element that enters into a higher temperature forced combustionof a fuel making it possible to avoid aviolently hurried combustion that would fuse the ash and result in clinker troubles or in the deposition of slag on the heating surfaces of the boiler.v

In explanation of these statements it may be noted that the degree of combustion being the same in both cases, as muchheat is liberated by a low temperature flame as by one of high temperature,-only the more rapid delivery of the heat being in favor of the'lat-- ter. Asv there is now no lack of radiant heat-absorbin surface. closely adjacent the sub-divided flame body in the combustion chamber, a hurried combustion is no longer required for the sake of boiler capacity; and

\ tibles in the lower Where desired it is possible to conduct the active combustion at temperatures which avoid the slagging of the fuel ash and make certain of a full recovery of the heat in the described sections of the boiler. Starting with a known furnace temperature directly above the grate or other source of fire, the temperature diminishes as the top of the combustion chamber is closely approached and the best practice is to designthe combustion chamber and the distribution of heat absorbing elements therein so that normally the gases which are extinguished by the exhaustion of combustion and have radiated their quota of heat, shall enter the convected heat section of the boiler at corresponding temperatures, no effort being made to pass into that section either burning gases or such that have temperatures greatly exceeding the ignition temperature of, the combuspart ofthe chamber; thus thehighest efficiencies are insured. Under these new and favorable conditions it appears that the requirement for excessive furnace temperatures no longer exists and that generally the factor of furnace temperature need be considered only -1Il relation to a desired rate of combustion within a combustion chamber of given size and with respect to the heat resisting and insulating character of the combustion chamber walls.

All of the described heat absorbing elements. and surfaces obviously receive heat by con vectionbut for the sake of clearness I have disregarded the convection values of the relatively small radiant heat section of the boiler. i

Further objects of the present invention are to embody the above defined structures,

functions and effects in a sectional or unit type steam boiler of a height which shall notbe excessive; which may be supported from below,

as contrasted with suspension from its top; which shall be almost wholly composed of water tubes and yet so constr'ucted that every tube shall be freely accessible from the interior of the boiler; and,- which shall be particularly constructed and designed to operate under the highest pressures required, without entailing the employment of the excessively thick walls thatcharacterize the steam drums and parts of the vhigh pressure steam' boilers commonlyused. i

Further, the present application has particular relation to steam boilers of steepled form in which the heat absorbing and water circulating elements or tubes of major extent, for absorbing the convectedheat, are substantially horizontal and all positioned above the chamberin which the radiant heat is efliciently developed and transmitted to the heat absorbing and water circulatingelements of-minorextent. Boilers embodying the present inventionare best built in unit .the-backand front walls of the boiler furnace and setting; and, which sections are of sizes-convenient for transportation and ere ction. ,The boiler-also is well adapted for efficient firing. And ,as already indicated, it does away with the necessity for heavy drums of large diameter which areusually necessary on high pressure steam boilers, and on the contrary, may embody relatively small drums and'water tubes and still meet all the requirements of the high pressures marking the present trend of boiler practice. The arrangement of the heat absorbmg headers and water circulating tubes is convenient for erection, renewal and repair and facilitates the insertion; removal or repair of arches and battle walls; "and, also provides the necessary space for superheater elements, where such'are used. In addition the circulating elements are so disposed and arranged as to provide for the most rapid separation of steam and the rapid circulation andcoursing of the water over the surfaces with which it contacts tofully protect the same, all. within a minimum of space and with a maximum steaming capacity and efficiency in proportion to the surface area, the number and weight of tubes and other boiler elements utilized. P I 1 Briefly, the invention may be defined as comprising a casing or setting containing a tall combustion chamber admitting of the substantially natural maturity therein of the flame of a body and of a long flaming fire, in combination with a steam boiler including wall forming header members of cylindrical form,

a majorextent of closel spaced heat absorbing circulating tubes horizontally connecting the upper portions of said header members and positioned above said chamber to receive the hot ases therefrom, and a minor extent of wide y spaced heat absorbing circulating tubes extending between the lower parts of said header members and serving to subdivide the flame in the. combustion chamber to thereby increase its radiant area and yet permit it'to rise to substantially natural maturity in said chamber, thus al-' lowing dutyof said major invention also comprises-many novel-combistruction, also as .the space in which com the development of maximum heat from the fuel burned and the absorption by. said header, members and. tubes of minor extent of radiant heat therefrom ahdicorrespondingly reducing the heat absorbing" extent of the boiler. Thepossiblev by reason of the tionof the boiler water,

what diagrammatic in character but they show all the elements and essentials of the invention and :will be clearly understood by those who are skilled in the arts of combustion, boiler making and boiler operation.

4 Further, for sake of brevity and clear-- ness, such parts as the steam gages, the water gages, blow-off valves, ofi going steam lines, feed water pipes and the like, have been omitted from the drawings. The application and use thereof is too well understood to require detailed'description.

For the convenient understanding of the usual proportions of my boilers, I have made the accompanying drawings on the'scale of one-quarter inch to the foot, (reduced in the printed patent) and generally these proportions may be relied upon; but I wish it to be understood that my invention is by no means limted thereto or to the precise structures illustrated or. to the preciseproportions or argitudinal section of my novel high pressure boller of the vertical drum type and in the best form thus far devised; the section being In said drawings Fig. 1 is a vertical lonone-half on the line 3-3 of Fig. 1 and the 1 other half on the line 3"-3" of Fig. 1, the better to depict the close and wide s acings of the water tubes which respective y comprise the lower and upper arts of the boiler. The pressure vessel or he disclosed is' 'of an extremely simple, farm; very rugged; and so constructed 'that its parts may freely expand and contract under varying degrees'of heat, without endangering or destroying; the structure. It stands upright upon a amework and. base which iler proper here supports the boiler and which base also epcloses the furnace chamber roper; that-1s, bustion is initiated. This vertical position of enforced circulaas hereinafter described}: I l.

Theboiler is chiefly characterized by front and rear header drums, 164 and 165, which standuponend', that is vertically, and are. comi ected. bymany vertical-rows of substantiallyhorizontal water tubes, 166 and 167. It' isdesirableby reason of the high pres sures to be sustained that the header drums, 164 and 165, shall be of small diameter. They are, therefore, only large enough to permit'the free entrance of a workman and the drum becomes' the comfortable performance of the work which he hasto do within them. The diameter of the drums obviously is a measure of ber of common dimensions is of greaterwidth than this and hence the present complete boiler is preferably composed of a plurality of the above described sections or units, all supported by a common framework and base structure and enclosed by common side walls as well illustrated in Figs. 2 and 3. These units are interconnected as by short cross tubes 168 for. the sake of free cross circulation between the units;-that is, to in-.- sure common water levels therein.

. "Incidentally, the cross-tubes, 168, furnishconvenient and stable supports for the wedge-shapedbrick, 169, that fill the spaces between respectively adjacent upright header drums. Obviously, the drums 164 and 165, comp-rise the chief parts or major portions of the front and back walls of the boiler. The brick are held in position and tle joints are closed by metal face plates, 1 0.

At the bottom of each drum is a step bracket, 17-1; and, the drums or headers thus find support on the strong cross girders, 172. The latter are preferably outside of the walls which form the furnace chamber and therefore are protected from the heat of the fire. The remaining details of the construction of the furnace proper and of the boiler setting as a whole will be clearly apprehended upon examination of the drawings.

Thedrums 164 and 165, have manholes, preferably in their tops, as shown in Fig. 1; and, as explained are large enough to allow a man to be lowered into them; and, obviously in that position it is an easy matter for him to work upon the ends of the many tubes, 167, 168 and 169. 1

, he parts, 173, appearing on the face of Fig. 2 and in Fig. 3, are cleanout holes and plugs, positioned opposite respective hOIlzontal tiers of water tubesPIt is convenient.-

to pass a rotary tube-cleaner through these holes and into the boiler tubes. However,

other tube cleaners may be taken or operated through the manholes of the drums.

The upright drums,-164 and 165, of each boiler section or unit, are preferably truly parallel and all of the tubes, 167, extend between them perpendicularly. The tubes, .167, therefore, occupy substantiallf horizontal positions. As shown, the groups of tubes, 167, may be counted in horizontal rows and also in vertical rows. The latter will be referred to as verti-planular groups. The

tubes, 167, are of such number as to be closely 1 tion to the lower part To generally typify the construction it has I been said that the water tubes of the boiler are substantially horizontal, but obviously this expression must be modified or explained when referring to the tubes, 166. The latter are the main circulation promoting tubes of the boiler and are inclined from the point where they leave the drum, 164, to the higher points at which they'enter the drum,-165. This pitch is sufficient to permit the free escape of the mixed steam and water from the tubes, 166, and into the drum, 165.

The entire space measured from the lower part of the furnace proper to the groups of tubes, 167, comprises the tall combustion chamber before mentioned and within this.

chamber the flames develop virtually without restraint by-reason of the illustrated vertiplanulan arrangement and wide spacing of the tubes, 166. The spaces between the vertipIanular groups thereof are wide enough to admit a man. This is provided for convenience in assembling and repairing the boiler and more particularly for the purpose of forming upright and free flame passages of such width as to permit the rise of flames therethrough; and, the persistence of ignition temperatures quite to the top of the combustion chamber. Obviouslyalso, the Vertiplanular groups 166, present adequateradiant heat absorbing surfaces; and, the physical presence of such groups withinthe combustion chamber serves to subdivide the combustion of fuel and, it is made possible to deliver the gaseous products of combuso the group of tubes, 167 at substantially the highest temperatures attained in the combustion chamber.

Whenever necessary or desirable the length of flame and gas travel among the 'tubes may be increased by installing partial fire-brick floors or arches in staggered relation upon the several horizontal rows of tubes; for example, as shown in Fig. 1;

Obviously the construction above described and which comprises two vertical within the drums,

' output of steam increases this efiect is indrums and the many tubes connecting them, is duplicated or represented in each boiler unit here shown. And in addition, the several units are interconnected so that vcommon water levels are'preserved therein.- The assembled units installed within the side walls, are provided with a common roof or top and have a common breeching or stack'connection;

When ready for operation theboiler is filled with water to about half the height ofthe group of tubes, 167. During operation, under .the eflect of the fire in the combustion chamber, steam is rapidly evolved in the inclined tubes, 167, and, a rapid circulation of water is promoted, first upward therein and 165, thence across to the the tubes, '167, and

drums,-164 through to the thence downward, for re-entrance radiant heat absorbing tubes, 166.

The steam .bubbles are not "immediately disengaged in the drums,,165, and hence the I level of the mixed water and steam in those drums rises to a greater height than does the level of. the substantially solid column of water occupying the drums, 164.' As the creased and niore and more of the tubes, 167,

are called upon foe the return of the water from the drums, 165, to the'drmfis, 164.

'- Much disengagement oat steam obviously occurs at the tops of the drums, 165, but als much of the disengagement takes place with Y in the tubes at the to of the group, 1.67. The

uppermost tubes, 16 during proper operac tion receive only so much water as is entailed by theprimin of the steam in the drums, 165, while at ower levels, the tubes, 167 distinctly operate after the manner of a flashboiler.

Thus, in 'every'part, the boiler operation takes advantage of the best possible conditions ior the transmis ion of the heat ofthe fireto the boiler water, and in consequence, boilers ofthis design, as measuredby the extent of heating surtace, will.be found m be of much greater capacity and ofhigher efficiency than the bo lers now commonly 1n-use.-.-. The free space above the water in the drums, 164,is ofsuch altitude and of such volume'thatjunphopportunity is 'ven for the precipitation of moisture from t esteam and in co 1 .u'enoe the output of steam at thetopsi of t e'=drum's,'164, is both clean anddry. f It appears to. v be distinctly advantageous to thus secure aboiler of relativel which: aracterize' e'taller- --1ow altitude, the5man advantages,1 benefitsboilers preferred" in aforesaid latent,

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The herein described steam boiler unit, comprising a pair of vertical steam and water headers, in combination with a plurality of verti-planular groups of steam and water tubes connecting said headers and perpendicular thereto, and, fewer verti-planular groups of water and steam tubes connecting the lower parts of said headers and inclined in relation .to the same and the first mentioned tubes.

2. The herein described steam boiler, comprising a plurality of interconnected units, each comprising a pair of upright steam and water headers, an combination with a plurality of.verti-planular groups of steam and water tubes, connecting the upper parts. of said headers and perpendicular thereto, and, fewer verti-planular groups of water. and steam tubes connectingthe lower parts of said headers and inclined in relation to to admit a workman, in combination with a plurality of closely spaced verti-planular' groups'ofsteam and water tubes, connecting the upper parts of said drums and perpene dicular thereto, and, fewer and hence more widely spaced planular gr ups of water and steam tubes connecting'te lower parts of said drums and inclined in relation to the I I same and the first mentioned tubes. 5

I 4. The hereindescribed steam boiler com prising a plural? of closely spaced and interconnected 'ts,

eachcom sedofapair of upright steam and water rums provided and of a size to admit a workmamin combination with a plurality v of closely spaced verti-planular groups of 1 with manholes steam and water tubes, connecting the up per parts of said drums and perpendicular spaced planular' ups of water'and steam tubes connecting zie lower parts of andthe first mentioned tubes.

'and characterized-by'wall-eompl brickbetween ve pa y gap- 116 rted bythe means which interconnect sand In E I l I signature.

thereto, and,-few'er and hence more widely ,13 .110 drums and inclined in'relation to the same the upper parts of 70

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