US1714977A - Underfeed stoker - Google Patents

Description

y 28, R. A. F ORESMAN 1,714,977

UNDERFELED STOKEIR Filed Jan. 26, 1925 Rfiforcsnau WITNESSES: 0 INVENTOR ATTORNEY Patented May 28, 1%29.

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ROBERT A. FOBESMAN, 01E MOORES, PENNSYLVANIA, ASSIGNOR TO VJESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION'OF PENNSYLVANIA.

UNDERFEED STOKER.

Application filed January invention relates to underfeed stokers fuel retorts lYly of the type embodying alternate and intervening tuyere banks, for its object to provide fuel feeding means for a stoker of the character designated which shall introduce fuel thereinto in a substantially unbroken sheet across the entire stoker width, said sheet being of relatively great thickness where entering the retorts and of relatively little thickness where passing over the front ends of the tuyere banks. 7

A further object of my invention is to provide apparatus for suitably supporting the front wall and for introducing air across the entire stoker width when employing fuel feeding means of the character above described.

In the accompanyingdrawing, Fig. 1 is a view, partially in section and partially in elevation,illustrating an underfeed stoker constructed in accordance with a preferred form of my invention; Fig. 2 is a plan view, partially in section, of the structure. shown in Fig. 1, being taken on the planev II'-II thereof; .and Fig. 3 1s a transverse section,

of the ram structure employed in the device of 1, being taken on the line IIIIII.

In the construction of underfeed stokers, it has been the usual custom to provide a fuel hopper across the stoker front with distant rams, generally of circular cross section, operating in front of the respective retorts, whereby fuel is introduced into the retorts and forced up .out of the latter and over the adjacent tuyere banks. Each tuyere bank has been capped by a locking tuyere merging with the front wall structure.

In accordance with the present invention, I provide lateral wings onrams of the aforementioned type, said wings extending into proximity with each other and I round off the upper end of the tuyere bank in such manner as to provide a fuel admitting opening in front of each tuyere bank, fuel being forced thereinto by said wings. In this manner, I introduce fuel into the furnace in a substantially unbroken sheet across the entire stoker width, said sheet being relatively thick at the respective retorts and relatively thin over the respective tuyere banks.

Referring to the drawing for a more detailed understanding of my invention, I show retorts at 10-10 in Figs. 1 and 2, said retorts being separated by tuyere banks 11a and it has 26, 1925. Serial no. 4,727.

and 17 the former being provided with eorrugations in the lower face thereof and the latter defining the upper boundary'of the fuel admitting opening to the furnace. The ends of the corrugations on the members 16 provide air openings at 18 through which air may be admitted across the entire furnace width'from any suitable source, said air preferably being supplied under pressure through a conduit such as that defined by 1 the I-beams 14: and 15, although any other desired air supplying structure may be employed. I a

Coaxially disposed infront of each retort 10 is a ram member 19', the cross sectional shape thereof being clearly shown in Fig. Briefly speaking, each ofthese rams may be be considered as comprising a body having two portions which are, respectively, rectangular and semi-circular in cross section, the semi-circular portion being below the rectangular portion, andnar-rower than said rectangular portion. Each ram- 1.9 is mounted for reciprocation inasuitably shapedj ram bOX and the respective sizes are such that said ram boxesare in abutting relation as indicated at 20 in Fig. 3. The-rams 19 are mounted for actuation in the usual manner as bya crank shaft 21. Fuel is supplied to the rams 19 as from a hopper 21. 7

Having thus described the arrangenrent of the structure embodying my invention, the operation thereof is as follows: Upon providing the hopper 21 with fuel and reciprocating the rams 1919, the fuel is passed in to thefurnace in a substantially unbroken sheet across the" entire furnace width. The relatively thick portions of the rams 1919 being disposeddirectly in front of the respective retorts, it follows that fuel is introduced at a relatively rapid rate into the retorts themselves, whereas it is .intro of the tuyere banks by the lateral lugs or ears upon the respective rams. Owing to the peculiar configuration of the upper ends of the tuyere banks, there is little or no clogging or 'eddying in the fuel stream, but it passes into'the furnace and over the stoker structure in a smooth and desirable ma nor as is conducive to best combustion results. All portions of the fuel bed are caused to move progressively onwardly so that all. portions of the fuel coke at an even rate, re sulting in an exceptionally even and desirable fire. I

By regulating theamount of air supplied to the openings. 18, the activity of combustion at the front end may be controlled with marked facility.

lVhile 1 have shown my invention in but one form, it will be obvious to those skilled in the artthat it is not so limited, but is susceptible of .various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon are imposed-by the prior art or are specifically set forth in the appended claims.

lVhat- I claim is:

1, In an under-feed stoker, the combination with means providing rearn'ardly extending retorts fand intervening tuycre banks, of a. continuous fuel hopper across the front of said stoker, a. ram box for each retort anddisposed beneath the hopper, a

fuel'ram in each ram box and'centrally located in front of each retort,'each fuelram being'provided with flanking portions ex tending approximately to the center'l of the adjacent tuyere banks, respectivcu and means for reciprocating said whereby fuel is introduced into each reton and over the ad acent tuyere banks.

2. inc combination WILD an unoer stokcr embodying alternate retorts and tuyere banks, of ram means for introducing fuc; the front-thereof, 1n the to in of a plurality of adjacent channels, each channel being'relatively thick at the center thereof and relatively thin at the lateral thereof, said channels abutting in planes substantially coincident with the. lolgitu dinal central planes of said tuyere banks.

3. In a fuel feedingstructure for an underfeed stoker embodyinga plurality of fuel January, 1925.

ROBERT A. FORESMAN.

retorts with intervening tuyere banks, a plurality of laterally abutting ram boxes each formed in cross section with a laterally extending rectangular portion and a semicircular portion beneath the rectangular portion, rams of corresponding shape in the rain boxes, and means for reciprocating the rams the rectangular portions of said rams adapted to introduce fuel into the upper portions of the respective retorts and over the adjacent tuyere banks and said. semicylindrical portions being adapted to introduce fuel into the lower portions of the respective retorts.

a. In a furnace, the combination of a n underfeed stoker including alternate retorts and tuyere banks; ram means for introducing fuel onto said stoker in a substantially unbroken stream extending across the entire width thereof; the stream of fuel having greater effective depth in front-of said'retorts than in front of said tuyerebanks; the construction and arrangement of the stoker and ram means being such that the forward ends of the tuyere banks are spaced rearvvardly of the effective workingportions of the ram means when said rain means are in their extreme forward position.

In a furnace, the combination of an underfeed s'toker comprising alternate retorts and tuyere banks,v said tuyere banks being flattened at their fuel receiving ends, a wall for saidifurnace extending across the front thereof and having its lower portion disposed above and spaced from the flattened ends of the tuyere banks so as to provide an unrestricted fuel feeding opening for the furnace, and ram means for introducing fuel onto said stoker in a substantially unbroken stream extending across the entire width thereof; the stream of fuel having greater effective depthin front of said retorts than in front of said tuyere banks; the construction andarrangement of the stoker and ram means being such that the forward ends of the tuyere banks are spaced rearwardly of theeflective working portions of. the ram means when said ram means are in their extreme forward positions.

In testimony whereof, I' have hereunto subscribed my name this sixteenth day of

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