US1698565A - Boiler furnace - Google Patents

Description

Jan. 8, 1929.

A. RUHR oILER FURNACE Filed Jn. s, 192s 2. shams-sheen a v Patented Jan. 8, 1929.

` i Tiara ics.

ARNOLD EHR, OE BERLIN,` GERMANY, AssIGNoE. To INTERNATIONAL COMBUSTION ENGINEERING COREORATION, or NEW YORK, N:="Y., A- CORPORATION oF DELA- WARE.

BOILER EUENACE.

Application led January 5, 1926, Serial No.

This. invention relates to boiler-furnaces, and more especially to that type of furnace in which the combustion space is very large-ly delined by boiler tubes subject to radiant heat. the invention being particularly useful in connection with stationary ,boiler installations burning pulverized coal.

It has heretofore been ,proposed in such pulverized Icoal burning installations to arrange water screens within 'the combustion chamber, such water walls or screens being composed of a plurality of boiler tubes or tubes connected into the circulation of the' boiler. These `have been employed on theside walls; the rear walls; above the ash pit,

and elsewhere.

In accordance with the present invention,

I propose to insure more effective and better circulation through such elements, while, at'.

means for enforcing circulation.

I accomplish the foregoing, together with such' other objects as may-hereinafter appear, or are incident to my invention, by means of a construction which'I have illustrated in the-preferred form in the accom- *panyin'g drawings, whereinv Fig. 1 isa fragmentaryverticalsection through a boiler-furnace embodying my improvements, and' Fig. 2 is a transverse vertical sectionv throug 'pone-half of the boiler-furnace shown in Figdl. l '7 Referring now to the drawings, the reference character Afdenotes the combustion@ chamber which' has an Outletthroat 7 atl its upper part, the .pulverized `coalbeing :1dmitteddownwardly into the upper part of the combustion chamber through the arch 8 by means of a row of suitable burners 9,v the fuel and flame stream taking a U-shape course through the combustion chamber, with combustion completed'before' the rstpass of the main boiler B is reached. A portion of the air for combustionis admitted through" the burners, and the balance is admitted through rows of air inlets 10 located at successive levels in the front wall 11,"which is j preferably made hollow, 4so that the combustion air admitted through the inlets 10 is heated in traversing the space within the front wall. lIn front of `the rear wall 12 of the combustion chamber is a water wall j a composed of comparatively closely spaced tubes 13, the upper ends ofwhich are conthe same time, 4dispensing with any lspecial/Al Figa- 2. A pnrV of tubes 18 connect each half 79,279, and in' Germany september a1, 1925.`

nected into the lower ormud drum 14 of the boiler. These tubes are preferably small 1in diameter, so as not to weaken the drum struc ture.v Pairs'of the tubes 13 are connected 'i at their lower ends into junctionblocks 15.A

Above the ash pit C- the combustion chamber is the water screen Z), such screen being composed of tubes 16 spaced well apart to permit the refuse particles gravitating out of the .fuel and flame stream to freely pass to the ash pit, such particles being thereby cooled below the melting 'point in orderthat the refuse'particles .may deposit in the" ash pit in readilyremovable form.

The upper ends ofthe tubes 16 are con-:53 nected into the4 junction boxes. 15,-and the' lower endsof the tubes 16 are connected A,into the header 17, this header being preferably divided 'by a division plate 17a into two vhalves .as indicated in dot and dash lines in of the header `17 with the mud drum 145, such tubes 18 constituting downcomers and being lpreferably somewhat larger in diameter than the tubes 16, which latter, in turn, are larger in'diameter than the tubes 13.

By this arrangement the water screen and.

the rear water wall a have local circulation therethrough, although they areconnected into the main boiler. It will also be seen soI that the water screen and the-water wall t are divided into two units or groups of equal number by tubes. This insures a moreuniform arrangement is such as to .insure rapid and unrestricted circulation through the water screen and the water wall, and to insure that the circulation shall aways beupwardly temporarily and even reverses. This is overcome by the downcomer connections 18 which 'areexterior of the combustion chamber, and Awhich-provide the local circulation hereinbefore referred to..

Coming'now to the screens or water'walls for the sidewalls Of the combustion chamber, it will be seen that I have divided this into twounits a?, e, there being preferably two such units, each of which is composedof small tubes 19. The tubes of' each unit passoutwardly f or connection into the headers-2Q, 20,'A

circulation through all of the tubes, and ove1- comes one ofthe diiculties heretofore encountered in this art. At the same time,' the at the top, and2l, 2l, at thebottom. A downcomcr 22 connects each of the low-er -headers 2l 'to themud, drum lll, and an upcomer 2:3

connects each of the headers 2O to the h xader 24, which, `in turn, is connected by a multiplicity of small pipes 25 to one of the upper drums of the boiler, this being done to preventu'ealicning of the drum structure, and to in securing an equalizingeject. as between the two units on each side wall ot' the combustion chamber. The pipes compare` in .size with the pipes 18, as do the pipes 23, and the pipes 19 compare in sizewith the pipes 13.

Thus, it will be seen that each unit has its op'n independent circulation, an( that by splitting the side water walls into these units, there is a tendency tosecure more unit'orm circulation therethrough, this end being` also v.

.t-,ujrthcred by having the pipesI 223 empty `into thc header 2l, asabove set forth. For reasons already Apointed out in Connection with the other units described, there will always be more eective and constantly upward How through the units (Z, e, ot each side water wall. These results are further ensured byI the fact that I connect the headers 20 and 21 by means of tubes 19a of which `there are a pair connecting each pairo headers, such tubes lying' exterir of the' furnace and constituting 'downcomers. By virtue of the local circulation thus made possible, flow through the dou'ncomers 22 is assisted. q

In order to prevent weakening-of the drum structure 14,I prefer to` connect 'the pipes IS and 22to headers 26,which4 in turn, are connected to the drum l-l by a plurality ot small pipes 2T. y

I claim zl i l. In combination, a boiler having upper drums and a lower muddrum and interconnecting' tubes, a combustion chamber', a. tubular screen for an upright -wall thereof, the tubes of which are divided into groups, upper and lower headers for each zgroup, a douncomer-'from the mud drinn to the lower header of each group, an upcomer from the upper header of-each group, and a downeomer from` .each upper to each lowerheader, a header common to the downcomers, a plurality ot' small tubes connec-tmg'said header to the upperand lower headers for each group, a..

downcomer leading,` from theboiler to' the `lower header ot' each group, an upcomerfrom the upper header of each group, a header common to the downcolners, a plurality ot smallVV tubes connecting. said header to the boiler, a header common to the upcoiners, and

a 'plurality of small tubesconnecting; said header to the boiler.

3. In combination, a boiler having upper steam and water drums and a mud drum, a

'bank ot upcomer tubes connect-ing said` mud drum with a steam and water drum. certain' of the tubes being subject to radiant heat, a bank of downcomer tubes connecting' a second of the steam and water drums with vthe mud drum, means connecting; the steam and water drums, a combustion chamber h'avingr tubular water 'walls detining'ya substantial portion of the combustion space and subject to radiant heat, and means connecting' said water walls into the circulation of the'boiler and arranged so that the delivery from tubes ot the installation subject to radiant heat is divided between the steam and water drums.

et. In combination, a boiler having a pair ot" upper steam and water drums, and a lower mud drum and interconnecting tubes, a combustion chamber, boiler tubes :tor an 'upright wall of the combustion chamber, downeomer lmeans from the mudl drum to said boilers tubes,'upcomer means from said boiler tubes' to one of the upper drums, boiler tubes for another upright wall of the combustion chamber, a bottom screen for the combustion chamber, downcomer means from the mud drum to said bottom screen, and means connecting said bottom screen to said last mentionedy boiler tubes, said last mentioned tubes being connected into the mud drum to deliver thereinto. I

In testimony' whereof I have hereunto signed my name.V

ARNOLD mitm.

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