US2362127A - Stoker - Google Patents

Description

J. GEHL Nov. 7, 1944.

STOKER Filed Feb. 9, 1940 'Inventur Patented Nov, 7, 1944 vgSTlHR "John Gehl, Denmarkv,fWis. y

.Application AFebruary 9, 1-&&0,1 Ser.iaL-No.31-8f,060

` TThisiinvention::pertains-generally to Istokersxof aithe-automatic underfeed iiring type, :and more rfpartcularly, to .I retorts employed-ins such :sto-kers. .1 The invention f has kprimar'ily .'for c its object to aimprovefzsltoker fretoiits iwitht respect v :toiincrease'd emciencyfoft:combustione andfgcons'equen't economy ioffuel. I y

,incidental fito the .ffore'go'ing,;,=a #more :specic subjectief :the inventionfresides in the provision aof 11a retort :equipped .with` a centrally finounted combustion fitube, :ifor.fgreatercdistribution of .eair through anderer the fuel bed to insure maximum combustion, and a more uniform distribution of fuel within the retort and combustion chamber.l n

Another object resides in the provision of means carried by the combustion tube for directing and regulating air supplied for secondarycombustion above the fuel bed, thus substantially consuming all fuel gases to provide maximum efliciency.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the novel construction, combination, and arrangement of parts, substantiallyas hereinafter described, and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come Within the scope of the claim.,

In the. accompanying drawing is illustrated one complete example `of the physical embodiment of the present invention constructed according .to the best mode so far devised for the practical application of the principles thereof.

In the drawing:

Figure 1 is a vertical section through a retort constructed in accordance with the present invention, the view being taken onthe line I-I of vFigure 2;

Figure 2 is a horizontal section taken on the line 2-2 of Figure 1;

Figure 3 is a detail section taken on the line 3-3 of Figure l; and

Figure f1 is a detail section taken on the line 4-4 of Figure 1.

Referring now more particularly to the accompanying drawing, the numeral I designates generally a retort, set within a refractory casing 2 forming a combustion chamber.

The retort I comprises an annular shell 3, terminating at its upper end in a flange 4, which carries an inne;l bowl 5, the bottom of which is spaced from the bottom of the shell 3.

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fro The ebowizavis ,mmviuediwnh @woedt-aimed- :missionfportsftz,avliichuallowiaindeliveredtofthe compartment I4 tto enter fthe -fbowl and pass through the fuel bed supported by the bowl.

Mounted centrally within the bowl 5 is a combustion tube I3, flared at its upper end, and

provided throughout its heighth with spaced discharge ports I4. As will be noted in Figure 1, the lower end of the combustion tube is open to receive air delivered to the compartment I I,

which, as stated, is discharged into the fuel bed through the ports I4.

It will be noted that the combustion tube in cross section has a circular rear wall intersected by front converging walls which form a knife-edge splitting blade for the fuel as it is fed to the bowl through the mouth of the fuel feed pipe, which pipe points `toward it. Thus the flow of fuel, with a minimum of resistance, is loosened up and divided to develop a porous body through which air is readily admitted from the bowl sides.

The upper edge of the combustion tube is provided with annularly spaced, arcuate notches I5 formed tangentially to the axis of the tube.

Threaded into a spider I6, formed in the upper par-1; of the combustion tube, is a cap plate I1, which may be vertically adjusted to regulate the opening between the top of the tube and the plate, to control the volume of air discharged from the upper end of the tube.

As will be noted in Figures 1 and 4, the bottom face of the plate I1 is provided with a plurality of radial arcuate grooves I 8, which cause air rdeflected horizontally by the plate to swirl over the top of the fuel bed B. Swirling action of air discharged at the top of the combustion tube is further augmented by the tangential arcuate notches I5 in the upper edge of the combustion tube.

Preferably, that side of the cylindrical tube I3 facing the feed opening 'l is tapered to an edge I3. Thus, as fuel is fed into the bowl 5 and contacts the tube I3, not only is resistance to the feed reduced, but the fuel is divided and directed to 55 opposite sides of the retort, thus bringing about a uniform distribution of fuel fn both the retort and combustion chamber, and, consequently, more even combustion.

In operation, green fuel is fed to the bowl of the retort l through the feed tube 8 by the screw conveyor 9, and, as thesame is forced upwardly, it gradually becomes coke above the retort; during which operation, gases are liberated which pass up through the fuel bed, and are consumed at the top ofthe bed by Vsecondary combustion. Y

Obviously, air distributed into the fuel bed through the ports I2 in the bowl 5, and the ports H in the central combustion tube I3, will uniformly pass through the fuel bed to bring about the most efficient initial combustion, resulting in gradual coking of the fuel; and, as the fuel gases are released during the coking operation, they must pass upwardly through the top of the bed, which is substantially incandescent. While the greater portion of liberated gas is consumed by the incandescent crust at the top of the fuel bed, such gas as may escape contacts the forced swirl of air discharged horizontally between the upper edge of the combustion tube and the cap plate 1 to bring about secondary combustion, with the result that practically all fuel gases are consumed, thus providing maximum efficiency and fuel econ- Omy.

From the foregoing explanation considered in connection with the accompanying drawing, it will be seen that a highly improved stoker retort said bowl having a plurality of air admission ports communicating with the air space between the shell and bowl, a fuel feed tube extending radially through the shell wall and communicating with the bottom portion of the bowl, a forced draft pipe communicating with the air space between the bottom of the shell and said bowl bottom, a vertical combustion tube centrally mounted in the bowl bottom and communicating with the said air space and having air discharge ports therethrough, the last namedtube in cross section opposite the said fuel feed tube being formed with a circular rear wall and tangential side Walls extending forwardly therefrom and converging to a splitting point opposite the mouth of the fuel feed tube, whereby the fuel fed into the bowl is broken up as it flows past the pointed edge of the combustion tube to break and loosen the mass and form air passages throughout the same.

JOHN GEHL.

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