US1404568A - Furnace - Google Patents

Description

A. H. BLACKBURN.

FURNACE.

APPLICATION FILED APR. 22, 1918.

Patented Jan. 24, 1922.

2 SHEETS-SHEET l.

Am H BLACKBURN.

' FURNACE.

APPLICATION FILED APR. 22, I918.

Patented Jan. 24, 1922.

2 SHEETSSHEET 2.

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'mmww 49M (MM UNITED STATES PATENT OFFICE.

ARTHUR H. BLACKBURN. OF DOWNJERS GROVE. ILLINOIS, AS SIGNOR TO THE UNDER- FEED STOKEB- COMPANY OF AMERICA. OF CHICAGO. ILLINOIS, A CORPORATION OF NEW JERSEY FURNACE.

Specification of Letters Patent.

Patented Jan. 24, 1922.

Application filed April 22. 1918. Serial No. 229,986.

a side plate construction for inter-position.

between the extreme retort and the side wall of a multiple-retort underfeed furnace. which plate is arranged, and may be properly air-cooled. to prevent or minimize clinker" adhesion to such plate and to the side walls. Further objects of my invention are to provide simple. etiicient. durable plate construction or side tuyere structure, and simple and convenient retaining and operating means. for the purposes described.

To these ends my invention consists in tl e features of construction and arrangement of parts hereinafter more fully described and claimed.

In the drawings Figure l is a perspective view of an undel'feed furnace with its front wall broken away: Fig. Qis a sectional elevation of a side plate and associated parts: Fig. 3 is an inverted plan view of parts shown in Fig. 2 with parts broken away: Fig.4; shows in section a modified cnibodh ment of my invention: and Fig. 5 is a secti n on .line 5-5 of Fig. 4.

It will be under tood that the general features of underfeed furnace construction shown in Figure 1, are for illustrative purposes only. as my invention may be applied to widely diti'erent constructions of multipleretort underfeed furnaces-z but in the specitic illustration 10. 10 represent masonry side walls of a furnace between which there spans the floor structure ll separating the combustion chamber or fire box 12 from the wind chamber 13. or source of supply of air under pressure. This tire box floor includes suitable retorts ll (of which I may term the outer ones extrer-ie" IGtolts and any others arranged therebetween meair' retorts) and intervening main tuyere structure comprising tuyere blocks 15 spanning the spaces between adjacent margins of adjoining retorts. the purposes of which are well known iIrtlie art. In this multipleretort type of furnace the fuel, fed axially along the retorts and rising to a height above the level of the crests of the main tuyerehloeks l5. burns intensely at and above the level of the tuyeres. and it is in this zone of maximum combustion that clinkering tendency most is m: nifested.

It has long been recognized that ditiiculty in the operation of these furnaces inheres in the fact that as the live coal is forced upwardly and spills laterally from the extreme or side retorts it tends to clinker along the sides of the furnace and to adhere to the dead plates and the side walls flanking the extreme retorts. just above the level of the main or retort-separating tuyere-blocks 15. so making adequate cleaning of the furnace diiiicult. This disadvantage is obviated by my present invention.

Spanning from the outer margins of the extreme retorts 14 of the series to the ad jacent side walls 10 I provide portions 16 of the floor in the form of inclined aircooled plates. preferably tuyere structures so constructed and disposed that air is caused to flow across the under side of the front or exposed plate surfaces. these plates upsloping steeply from the retort-margins and extending high enough above the level of the tops or crest of the main tuyere blocks to receive the side pressure of the fuel that in the active stage of combustion conducive to clinkering and therefore to include the zone of detrimental clinker-forination. The cooling air may flow through passages 17 formed in the plate structure opening .-t one end as at 15 to the wind chamber 123 and opening at the other end as through tuyeies 19 toward the adjacent retort. Further. I prefer that the portion of the wall or partition that forms the under side of the stated air passage. closely subjacent to the tuyere openings 1 shall be movable to uncover a dump opening for dropping any ash that may accumulate in the air passage.

In the specific construction shown in Figures l to 3 the plates 16. identically alike.

are relatively short blocks arranged side by side, the matter of block length being one of manufacturing convenience and facility in assemblage. Each block has its front wall 20 extending. with the slope greater toward its bottom than at its top. from the edge of a retort H to the adjacent side wall 10 rising. as shown. materially higher than the main tuyere-blocks 15, so

' may be at any suitable point in the front shaft 34 or 34'.

that each side of the fire-box has a steeplyinclined side-border flanking the zone of most active combustion and aircoolcd to prevent clinker-adhesion. A flange 21 gives the block'angular hearing on the retort and a head wall 22 of the block rests against the side wall 10 of the furnace. The tuyere openings 19 are preferably a pair of slots made near the lower end of the front wall, although as shown at 19 in Figure 4 they wall 20- relatively remote from the head wall 22 of the block. The front wall may be strengthened by a rib 23 extending fromthe wall to the spacing web 2% between the tuyere slots. Each block has end walls 25 and a bottom wall or partition 26 that extends from below the tuyere openings toward the head wall 22 leaving an air intake opening :27 near the latter through which air may pass from the wind chamber 13 to the air passage 17, to sweep across the under side of the front wall and escape through the tuyere slots 19. In the construction shown in Figure 2 a portion of the bottom wall as is stationary and is supplemented by a hinged door 28 controlling a dump-opening 29 immediately below the tuyere slots. In the construction shown in Figure 4; the bottom wall 26' has a slide 28 mounted on guide ribs 30, so that when in the position shown in Figure 4 it closes the space below the tuyere slots. and when retracted opens the dump space 29.

The several blocks or plates are individually removable for replacement, but are held in position by'the common holding means such as a rod 33 or 33, and the movable dumping means of all the doors are preferably operated in common as from a rock In the construction shown in Figure 2 each plate has ears apertured to receive the retaining rod 33. which also engages and is positioned by brackets 36 embedded in the masonry wall. brackets may also support the rock shaft which extends beyond the front wall of the furnace and is provided with a rocking lever 37. Crank arms 38 on the rock shaft, connected by links 39 with the doors 28 control the movements of the latter. In the construction shown in Figure 4 similar brackets'36' receive the rod 33 that engages ears 35. and the rock shaft 34 has crank arms 38 making pin-and-slot engagement with the slides 26. b

It will be apparent that the inclined side plates rising above the,zoneof maximum combustion tend'to prevent any live coal from coming in contact with the side walls of the furnace where it might clinker, and that the air cooling of the plates, preferably by a draft which is forced to. travel transversely of the plates from the b0tt om inlet 27 to the tuyeres 19 will effectlvely prevent These stances, be available for installation in furnaces already constructed. with a m nimum of change in the masonry. Thus, it will be understood that while in original building the embedding of the brackets 36 in the masonry walls is desirable for cheapness and simplicity. it. may in many instances be dispensed with and. in old furnaces. side plates embodying my invention may be installed with no alteration of the side wall construction.

along the adjacent side-re- While I have herein shown two specific embodiments of my invention that I have found to be practically satisfactory. it will be apparent that changes in detail might be made without departure from the spirit of my invention within the intended scope of the claims.

What I claim is:

1. In an underfeed furnace. the combination with the fire-box and wind-chamber walls. the plurality of longitudinal retorts spaced apart and spaced from the side walls, and the main tuyere blocks extending between adjoining retort-margins; of side plates extending from the outer side margins of the extreme retorts to the side walls, each of said side plates having a wall facing toward the combustion space and sloping upwardly and outwardly throughout its span from the retort-margin to the side wall. and with its upper edge materially above the plane of the tops of the main tuyere blocks and extending above ,the normal zone of clinker-formation. whereby fuel that is in the active stage of combustion conducive to clinkering will be retained by said side plates and clinker-formation along the sides of the fire-box is minimized.

2. In an underfeed furnace. the combination with the tire-box and wind-chamber walls. the plurality of longitudinal retorts spaced apart and spaced from the side walls and the main tuyere blocks spanning between adjoining retort-margins: of nonclinkeriug air-cooled side plates spanning from the extreme retorts to the fire-box side walls, these plates sloping upwardly away from-the extreme retorts to said side walls and at their outer edges meeting said side walls materially above the level ofthe tops of the main tuyere blocks to include below' their outer edges the normal zone of clinker-formation, and said side plates having tuyeres opening through their front faces relatively remote from said outer edges: whereby clinker-formation along the I fire-box side walls is minimized.

3. In an undi'feed furnace, the combination with the fire-box and wind-chamber walls, the plurality of longitudinal retorts along which" fuel may be fed, these retorts being spaced apart and spaced from the side walls, and the main tuyere blocks spanning between adjoining retort-margins and receiving air from the wind-chamber therebelow; of non-clinkering side plates spanning the spaces between the extreme retorts and the fire-box side walls and aircooled from the wind-chamber therebelow. said side plates merging into and sloping upwardly and outwardly from the outer margins of the extreme retorts and at their outer edges meeting said side walls materially above the level of the tops of the main tuyere+blocks and abovethe normal zone wherein fuel will be in that stage of active combustion conducive to clinkering; where- '25 by to restrain such actively burning fuel in a bed noncontacting with the fire-boxside. walls to minimize clinkering on said side walls and in position to 'be fed longitudinally with the fuel of the adjacent extreme retorts. I 1

4. The combination with the walls. plurality of parallel retorts spaced apart and spaced from the furnace side walls and along which fuel may be fed, and the main tuyere blocks spanning between adjacent retort-margins, of an under-feed furnace that has a wind chamber below the retorts: of non-clinkering side plates spanning the spaces between the outer margins of the extreme-ret0rts and the adjacent side walls, said plates sloping upwardly from the outer margins of the extreme retorts to the side walls of the furnace and meeting said side walls materially above the level of the tops of the main tuyere blocks to restrain the actively burning fuel in a bed non-contacting with the furnace side walls and in position to be fed longitudinally with the fuel of the adjacent extreme retort, each said side 0 plate comprising a plurality of relatively short blocks each having a front wall with a tuyere opening, having also a head wall for contact with the side wall of the furnace and having also other walls including a bottom wall, saidside-block walls being formed and arranged todefine an air chamher that has a downwardly opening intake and that extends thence inwardly and downwardly below the inclined front face of the block to the tuyere opening.

5. The combination with the walls. plurality of parallel longitudinal retort-s spaced apart and spaced'from the furnace side walls. and the main tuyere blocks bridging 5 the spaces between adiaoentretort-margins,

of an underfecd furnace that has a wind chamber below the rctorts: of non-clinkcr ing side plates bridging the spaces between the extreme retorts and the furnace side walls, said plates sloping upwardly away from the outcr margins of the extreme retorts to the side walls of the furnace and meeting said side walls materially above the level of the tops of the main tuyere blocks. said side plates having tuyeres opening through their front faces. each said side plate comprising a plurality of relatively short blocks each having an apertured portion extending from its underside toward the adjacent furnace side wall, supporting means mounted on said furnace side wall and extending toward said apertured parts, and a retaining rod engaging said apertures and said supports.

6. In an underfeed furnace. the combination with the side wall and a retort spaced therefrom. of brackets mounted on the side wall. a rod mounted in said brackets. 21 rock shaft mounted in said brackets. an aircooled plate structure spanning the space between the retort and the furnace side wall blocks each hollow throughout a portion of its width and having an intake opening adjacent the side wall and a tuyere opening toward the retort. each said block having rod-engaging portions and each having a movable portion adjacent the tuyere opening, for dumping ash deposits accumulated through said tuyeres, and means carried by said rock shaft for operating said movable portions.

T. In an underfeed furnace. the combination of the walls of a firebox and a Sub: jacent wind box for supply of air under pressure. a plurality of substantially-parallel retorts along which fuel may be fed these being spaced apart and an extreme one thereof spaced from the contiguous wall of the fire-box. main tuyere-structures span ning between adjoining retort-margins. and another tuyere-structure spanning from the outer margin of the extreme retort to the contiguous wall of the fire-box and sloping steeply upwardly and outwardly from the retort with its outer edge so materially higher than the tops of said main tuyere structures as to present its sloping face toward and to extend substantially to the top of the normal zone of clinker formation.

8. In an underfeed stoker, the combination of a plurality or closed-bottomed retorts along which fuel may be fed arranged side by side and spaced apart to leave air spaces therebetween: main tuyere-structures spanning between adjoining retorts, arranged to be covered by the up-piling fuel bed and having their tuyeres opening from said air spaces toward the retorts to supply air for fuel combustion; a fire-box wall alongside of and spaced from an extreme one of said retorts; another tuyere-structure upwardly and outwardly sloping from the outer side of said extreme retort to the adjacent fire-box wall and rising to a height so materially above said main tuyere-structures as to include below us top the normal tures.

ARTHUR H. BLACKBURN.

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