US2015526A - Stoker - Google Patents

Description

P. A. KETCHPEL 2,015,526

STOKER Filed Nov. 2, 1931 S'SheetS-Sheet l- Sept. 24, 1935.

IN VEN TOR.

ATTORNEY.

Sept. 24, 1935. P. A. KETCHPEL 2,015,526

STOKER Filed NOV. 2, 1951 3 Sheets-Sheet 2 INVENTOR. y

ATTORNEY.

Sept. 24, 1935. P, A; KETCHPEL 2,015,526

STOKER Filed Nov. 2, 1931 3 Sheets-Sheet 3 INVENTOR ATTORNEY Patented Sept. 24, 1935 PATENT OFFICE STOKER.

Paul A. Ketchpel, Bergenfield, N. J., assigner to The Standard Stoker Company, Incorporated, a corporation of Delaware Application November 2, 1931, Serial No. 572,610

4 Claims.

'Ihis invention relates to improved stoking mechanism for firing furnaces, particularly furnaces of the type in which the rebox grate 1s comparatively wide with respect to the depth' yI thereof, and more particularly to stoking mechanism for firing furnaces of marine boilers.

In marine service it is common practice to use furnaces of the type having comparatively wide but short firebox grates. Furnaces of this type l0' are provided with a number of openings spaced apart along the front, through which fuel is delivered to the firebox. In manual ring of such furnaces it is impossible to maintain an even distribution of fuel over the lire since it is physically impossible for the fireman to fire through the several openings simultaneously.

In manual firing it is the practice to cover the live re with a large excess of green coal and when it has burned through add another large excess of green coal. There is as a resulta great fluctuation in boiler pressure and a large loss of eiiiciency. Repeated opening of the firebox door for hand firing furthermore admits an excess supply of cold air over the re with consequent decrease in efliciency of fuel combustion.

Furnaces of the type described are extremely diiiicult to re by mechanical means and it is an object of this invention to provide a simple and efficient mechanical stoking arrangement which will maintain an -even and continuous distribution of fuel over the entire firebox.

It is a further object of this invention to provide a mechanical stoking arrangement, in furnaces of the type described, which Will permit eicient delivery of fuel thereto without interfering with the hand firing and the inspection, cleaning and repair of the boiler and furnace.

Other and further objectsand advantages of the invention will be apparent from the description when viewed in the light of the accompanying drawings, in which Fig. 1 is a side elevation of the invention as applied in a marine installation with portions of the fuel bunker and furnace room shown in section;

Fig. 2 is a partly diagrammatic fragmentary plan View showing the invention as applied on the left side of the furnace and fuel bunker with 5o portions of the fuel bunker and furnace room shown in section;

Fig. 3 is a detail View of the fuel distributing arrangement of Figures l and 2;

Fig. 4 is a detail View of an elbow for deliver- 55 ing fuel to the furnace;

Fig. 5 is a modified form of the stoking arrangement;

Fig. 6 is a detail view of the fuel delivery elbow of the modification shown in Fig. 5, and

Fig. 7 is a plan view of the structure shown 5 in Fig. 1.

The preferred form of the invention, illustrated in Figures 1 to 4 inclusive, Will be described as applied in a marine installation, though it will be obvious that the invention is also applicable 10 in other furnace installations.

The bottom wall of the hull of a vessel is shown at I0, and the deck of the furnace room at II. The furnace is designated generally by the numeral I2 and comprises the iirebox I3, grates I4, 15 front wall I5 and sidewalls I6. spaced at intervals along the front wall I5 of the furnace are the usual hand firing openings I'I, the number depending on the width of the furnace.

The fuel bin is shown at I8 and is provided 20 with the floor I9 constituting a continuation of the deck I I. 'I'he floor I9 is provided on each side with a longitudinal opening 20. Located between the fuel bin floor I9 and the bottom wall Il of the vessel and communicating with the fuel bin 25 I8 through the opening 20 is the open mouthA trough member 2|, forming the rearward portion of the fuel transfer conduit 22. The forward portion of the fuel transfer conduit 22 is formed by the tubular conduit section 23, constituting an extension of the trough member 2l. Slide plates 2d are sldably mounted in the marginal edges of the floor I9 bordering the opening 20, so that they may be moved to uncover or cover the opening 20 in a manner to control the delivery of fuel to the trough member 2l.

Conveyor screw 25 is mounted in the transfer conduit 22 for advancing fuel forwardly therethrough. Rearward of the trough member 2I and extending transversely beneath the fuel bin floor I9 is formed the compartment 26. Housed within the compartment 26 is the gearing 2l and drive shaft 28 for operating the conveyor screw 25. The drive shaft 28 is operated by 45 the motory 29, mounted at one side of the fuel bin and beneath the deck II. Access to the motor 29 and the compartment 26 may con-y veniently be had through the door 30 in the deck II.

The furnace I 2 is provided with the opening 3l through the sidewall I6 adjacent the front Wall I5, at a suitable height above the level of the grates I4 for scattering fuel in aerial paths thereover. Riser conduit 32 extends upwardly and 55 forwardly from the forward end of the transfer conduit 22 and communicates at its upper end with the opening 3|. Conveyor screw 33 mounted in the riser conduit 32 is universally connected with the transfer conveyor screw 25, as at 34, and delivers fuel to the opening 3|.

The upper end of the riser conduit 32 terminates in the inwardly and downwardly curving elbow 35. The elbow 35 is provided with the flange 3e for attachment to the marginal edges of the furnace wall bordering the opening 3i, by suitable means, as bolts 3l. Formed with the elbow 35 adjacent the bottom of its delivery end is the chamber 38. The chamber 38 is divided into any desirable number of compartments 33, and pressure fluid is delivered to the compartments 39 from a suitable source, as from the boiler, through the pipes 4E). The pipes 40 connecting with the compartments 39 may be controlled by valves. Pressure fluid is emitted from the compartments 3S through any suitable number of jet openings 4i. A quadrant shaped distributor plate l2 extends forwardly from the lower forward end of the elbow 35, and carries diverging ribs 43 on its upper surface for spreading the fuel over the firebed.

The invention has been described with reference to that portion of the fuel bin and furnace to one side of its longitudinal center line, but

it will be understood that the other side is similarly equipped with fuel conveying and distributing means so that the stoking arrangement on the one side of the furnace and fuel bin is the exact counterpart of the stoking arrangement on the other side thereof.

By admitting fuel to and distributing it from the corners of the rebox, a more complete utilization of the effective grate area is obtained. The corners of the lrebox are never as effective heat producing areas as the other parts of the flrebox since they are difficult to fire properly; therefore by utilizing these `less effective heat producing areas to accommodate means for introducing the fuel into the rebox, the more effective parts of the rebox area may be maintained unobstructed by fuel delivery and distributing mechanism. With the present improved arrangement for delivering fuel to furnaces of the type described, the amount of coal particles and cinders carried into the flue is minimized, since ,the greatest part of the fuel is projected at an angular direction with respect to the direction of the draft.

Each of the conveying and distributing systems delivers fuel to and scatters it uniformly over a half of the grate area. By delivering the fuel through the sides of the furnace in the direction of its longest dimension, it is possible to uniformly distribute fuel over the grate with a minimum number of delivery points.

In Figures and 6 is illustrated a modified form of the invention in which fuel is delivered from a bin (not shown) to a hopper 44 located at the front of the furnace midway between the sidewalls it. A tubular conveyor conduit 45 extends horizontally along the front wall I5 of the furnace and is provided with an opening communicating with the bottom of the hopper 44. A screw conveyor 45 is rotatably mounted in the conduit 45 and is provided with the oppositely inclined flights il and 48. The flight 41 is arranged to convey fuel to the left side of the furnace and the flight 48 is arranged to convey fuel to the right side of the furnace. The screw flights 4l and 48 are provided at their opposite ends with the blade-like ends 4S for pushing the fuel at right angles to the direction of the conduit. The conduit 45 terminates at each end in a downwardly and inwardly curving elbow 50 arranged to deliver fuel to the furnace through 5 the openings 5i in the sidewalls of the furnace adjacent the front wall l5. A slide gate 52 at the bottom of the hopper 44 is provided so that the amount of fuel delivered to the conduit 45 may be conveniently regulated and controlled to deliver more or less fuel to one side than the other. In operation fuel is delivered to the conduit 45 from the hopper 44 and is conveyed to the elbows 5f) by the screw conveyor 46. It passes through the elbows 5G into the rebox i3 and is 15 scattered over the fire in the same manner as described in the preferred form of the invention.

I claim:

l. In combination with a furnace having a front wall, sidewalls and a grate surface of greater width than depth, a fuel bunker, a single fuel admission opening in each of said sidewalls adjacent said furnace front wall, a pair of fuel transfer conduits at opposite sides beneath and communicating with the fuel bunker, a pair of riser conduits extending upwardly and forwardly from the forward ends of said transfer conduits to points adjacent the tops of said openings, each of said riser conduits terminating in a downwardly and inwardly curving elbow, each of said el- 3'0' bows extending into a respective opening, a screw in each of said transfer conduits advancing fuel to said riser conduits, a screw in each of said riser conduits for elevating fuel to said elbows,

and a fuel distributing plate arranged at each of said openings to receive the fuel dropped by gravity through said elbows.

2. In combination with a furnace having a front wall, sidewalls, a rebox and a grate surface of' greater width than depth, a fuel bunker, 40`

a single fuel admission opening in each of said sidewalls adjacent said furnace front wall a sufficient distance above the level of the grate to permit scattering fuel in aerial paths thereover, means for delivering fuel from said bunker to said openings including a pair of transfer conveyors receiving fuel from the bunker and eX- tending forwardly therefrom, a pair of elevating conveyors extending upwardly and forwardly from said transfer conveyors to the upper portion of said openings, each of said elevating conveyors terminating at its upper end in a .downwardly and inwardly curving elbow, each of said elbows extending into a respective opening, and a quadrant shaped 55 distributor plate in each of the front corners of said firebox at the delivery end of each elbow.

3. In combination with a furnace having sidewalls, a front wall and a grate surface of greater width than depth, a source of fuel supply, a single fuel admission opening in each of said sidewalls adjacent said front wall, mechanical means for conveying fuel from the source of supply to said openings, said means including a pair of conveying elements, each receiving, fuel from the source of supply and delivering toward its respective opening in a sidewall, downwardly and inwardly curving elbows each receiving fuel from the discharge end of its respective conveying element and delivering to its respective open- 70.

wardly and inwardly curved elbow, a pressure uid lead communicating with such chamber, and a wall at the delivery end of said elbow provided with jet openings leading. from said chamber and arranged to issue blasts of pressure fluid over the iirebed.

4. In combination with a furnace having side walls, a front wall and a grate surface of greater width than depth, a source of fuel supply, a single fuel admission opening in each of said side walls adjacent said front wall, mechanical means extending across said front wall for conveying fuel from the source of supply to said openings, said means including a pair of conveying elements, each receiving fuel from the source of supply and delivering toward its respective opening in a side Wall, downwardly and inwardly curving elbows each receiving. fuel from the discharge end of its respective conveying element and delivering to its respective opening, and a fuel distributing member at each of said openings receiving fuel from its respective elbow and scattering the fuel over the flrebed, each distributor member including a chamber formed beneath the bottom wall of the downwardly and inwardly curved elbow, a pressure fluid lead communicating with such chamber, and a wall at the delivery end of said A elbow provided with jet openings leading from said chamber and arranged to issue blasts of pressure fluid over the rebed.

PAUL- A. KETCHPEL.

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