US1984441A

US1984441A - Method of combustion

Info

Publication number: US1984441A
Application number: US336524A
Authority: US
Inventors: John F O Stratton
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-01-31
Filing date: 1929-01-31
Publication date: 1934-12-18
Anticipated expiration: 1951-12-18

Description

Dec. 18, 1934.

J. F. o` STRATTON METHOD OF COMBUSTION Filed Jan. 51, 1929 /Lf 51 f'@ wif/mw 0&7? 70,5??

Patented Dec. 18,1934

V UNiTED STATES Parlizrrrk OFFICE Y l l 1,984,441r l l' f METHoD or coMUs'rroN John F. o. Stratton, Pelham Manor, N. Y.

Application January 31, 1929, Serial No. 336,524

3 Claims.

The present invention relates to a new and improved method of oxidizing fuel.

One of the primary objects of the invention resides in the provision of a novel method of fur? nace combustion in Which a highly turbulent condition is created and maintained.

Another object is to provide a new and improved method of combustion in which turbulence in the furnace is created by aV controllable agent, such as an air blast, which isindependent of the chemical composition of the fuel, variations in the temperature, and the volume of the products of combustion leaving the furnace.

:Another important object of the present invention residesV in the provision of a novel method 'of lfurnace, combustion in which the different stages of combustion are carried out under proper conditions and in which an adequate time ele ment is provided.

The present invention is particularly adapted for use in furnaces of the general character disclosed in my Patent No. 1,640,158, in which crushed coal is burned in suspension in an upwardly directed blast of air. The blast of air enters the combustion chamber from a nozzle defined by a slot in the bottom, and the chamber is greater in height than the maximum blast. For convenience, this method will be termed as a method of Vertical jet combustion.

- A further object of the invention resides in th provision of a novel method of vertical jet cornbustion in which preferably crushed coal is burned, and in which, regardless of the form of the coal used, the coal is introduced not directly into the top of the blast, thereby providing a substantial time element insuring complete combustion, and more particularly substantial combustion before the particles reach the top of the blast.

Still another object isto provide a method of verticalI jet combustion in which the different phases of combustion are carried out successively'in` an'increasing'temperature gradient in a single combustion chamber and in which a substantial time element for the completion of eachI phase is provided. f

A more specific object resides in the provision oi a novel method of vertical jet combustion in which a counteriiow is set upbetween the incoming and outgoing products, the outgoing products serving to preheat the incoming products, and the latter serving to protect the walls of the combustion chamber from the intense heat of the outgoing products.

An important object of the invention resides in the provision of a novel method of vertical jet (Cl. 11G-28) combustion in which the air blast is directed into a combustion chamber substantially larger in lateral. cross-section and height than the blast so as to constitute the blast a central upwardly eX- panding core and to cause the blast to induce a downward flow in the core surrounding space at the side walls of the chamber, and in which the fuel is introduced through one` or' more of the side walls into the space of downward trend. The fuel in the course of its downward rncvement is heat- 1 ed by radiation from the incandescent blast, and protects the sidewalls from excessive temperatures, and then entersI they baseof the blast as coke. A long tortuous path, of increasing temperature gradient fork the combustible particles 1 and gases thus is provided.

Other objects and advantages will become apparent as the description proceeds.Y

In the accompanying drawing, Fig. 1 is a vertical sectional view' diagra-rnmaticv in character and taken substantially along line 1-1 of Figure 2 of a furnace adapted for carrying out a method of combustion embodying the features of my invention. I

Fig. 2 is a transverse sectional view taken substantially along line 2 2 of Fig. 1.`

The vmethod may be carri-ed outlfin furnaces' or diiferent constructions., of which the furnace shown in the drawing is the preferredv form.

The furnace comprisesy a vertical combustion chamber 10v of suitable form. In the present instance, lthe chamber. 10 is rectangular in horizontal cross-section, comprising side. walls l1, l2, 13 and 14. The bottom of the chamber 10 is partially closed. by four

inclined end walls

15, 16, 17 and 18 converging downwardly from the side walls respectively. The wallsv l5 to 18 at their lower edges dene a relatively narrow elongated opening 19 constituting the upper edge of a throat'. `20, and serve to direct coal and slag fall- 40 ing thereon toward the throat.

Underlying the combustion chamber is a closed ash pit 21 which also serves as an air pressure chamber. Ashes may be removed from the pit21` through an opening 22 normally closed 45:

by a door 23.

Preferably-the throat is surrounded byan air chamber 24 which opens downwardly into` the ash pit 21 and which is connected through a duct 25 adapted to receive air under pressure 50 two sections 27 defining a narrow elongated in- 5 5 `terrnediatev slot 28 extending longitudinally of the throat, and serving as a nozzle for directing a vertical blast of air from the ash pit 21 into the combustion chamber 10. The sections 27 are adjustable to permit adjustment of the width of the slot 28, and preferably are movable as a unit transversely of the throat 20 so as to shift the region of the air blast, the operating means therefor being more fully disclosed in my said prior patent. l

The furnacemay be utilized as the heating means for a variety of heat absorbing units, and for purposes of illustration is shown in connection with the boiler comprising suitable heating tubes 29 disposed in a ue gas chamber 30 communicating with the top lof vthe combustion chamber 10.

The cross-sectional area of the combustion chamber 10 is substantially larger than that of the air blast throughout most of its intense portion from theinlet. Hence, while there may be no sharp line of demarcation, and while the blast may shift withina limited range, the blast constitutes a central core separated from the walls 11 to 14 by a core surrounding space. The air blast creates a suction in the bottom of the chamber about the blast inlet, thus causing a V downward trend of gases in the coresurrounding space.

While the invention is not limited to specific dimensions and angles, I have found that good results are obtained if the expansion of the effective portion of the air blast is limited to approximately 18 fromthe vertical. Preferably, the end'walls 15 and 17 are inclined approximately 52 to the horizontal. i As a result, the core surrounding space expands approximately 20" along the walls and 17.

'Means is provided for introducing any suitable fuel, preferably crushed coal, into the space of downward trend surrounding the central core. This 4means may be of any suitable form, and may be provided in any one or more ofthe side walls 11 to 14, and in the present instances comprises a `pair `of downwardly and inwardly inclined openings`31 in each wall. The Vertical position of these openings may be differentfor difficult kinds 'of fuel, depending on the time element desired.

In operatiomthe strong central air blast trends upwardly and Dinduces a downward trend of gases inthe surrounding space along the side walls 11 to 14.' `Crushed coal is introduced into the space of downward trend. In the course of .its downward movement, the coal is heated, by radiation from the. incandescent central core, through the distillation phase, the light and volatile hydrocarbonsand other ingredients being extracted to form a light coke. The temperature in the outer zone is relatively low, and the downwardly moving products ,shield and protect the adjacent walls of the chamber 10 from the intense heat of the core. l y

The coke and combustible gases from the outer zone enter the base of the blast, and are immediately erupted. The coke rst passes through the Yreduction phase, i. e., is heated to the temperature of the blast to prepare it for oxidation. The reduction phase is completed before the fuel particles reach the top of the blast. The particles are completely oxidized in the blast. The particles during the oxidation phase are molten and hence relatively heavy, particularly when crushed coal as distinguished from powdered coal is used. As they reach the top of the blast, they fall back and are again erupted. The molten ash particles specifically heavier descend to the bottom of the chamber 10, and pass through the throat into the ash pit 21. i

The blast creates a Violent turbulence which prevents stratication and the formation of relatively quiescent gas pockets, and which hence produces a thorough intimate mixture of fuel and air. This turbulence being created by the blast, can be positively controlled by regulating the blast. Due to the counterflow of the incoming products and the blast, a long tortuous path for the combustible, and a substantial time element are provided. The phases of combustion are separated along an increasing temperature gradient, although no sharp lines of demarcation may exist. Raw unburned particles are not present at the outlet of the chamber 10, and the combustion is complete. Any particles of fuel and ash present at the outlet are relatively heavy. As a result, no particles of fuel, ash or impurities such as sulphur are carried over to the heat absorbing surfaces.

Y I claim as my invention:

1. The method of combustion which comprises directing a blast of air of combustion upwardly into a combustion chamber in laterally spaced relation to the sides of the chamber so as to induce a downward trend of gases about the confines of the upward blast, and introducing crushed coal into the zone of downward trend about said blast for ultimate suspension and oxidation in said blast.

2. The method of combustion which consists in introducing an upward blast of air in a combustion chamber spaced inwardly from the side walls thereof so as to induce an insulating down draft along the side walls, directing said down draft inwardly toward the base of the blast, and introducing comminuted fuel into said down draft for movement with said down draft toward the base of said blast whereby said fuel is heated and combustion initiated by the heat from said central blast, and completing the combustion of such fuel as it is moved upwardly after it has encountered said blast.

3. The method of combustion which consists in introducing an upward blast of air into a combusticn chamber, t-he blast being so regulated as to define a central core having diverging limits within an angle of 36 and being spaced inwardly from the side walls of the chamber a minimum of 20 to induce an insulating down draft along the side walls, directing said down draft inwardly towardthe base of the blast, and introducing comminuted fuel into said down draft for movement with said down draft toward the base of said blast whereby said fuel is heated and combustion initiated by the heat from said central blast, and completing the combustion of such fuel as it is moved upwardly after it has encountered said blast.

JOHN F, O. STRATTON.