US2384588A - Steam generator - Google Patents

Description

STEAM'GENERATOR Filed March 16, 1944 2 Sheets-Sheet l 2 Sheets-Sheet 2 S TEAM GENERATOR J. P. BADENHAUSEN Filed March 1e, 1944 Sept. ll, 1945.

Patented Sept. 11, 1945 UNITED TES Param" oFricE 8 Claims.

This invention relates to steam generators and more particularly to steam generators adapted for burning pulverized anthracite coal or anthracite culm as well as other fuels.

It is the principal object of the present invention to provide a steam generator capable of use with small sizes of fuels of various sorts for effective steam generation.

It is a further object of the present invention generation adequately protected from the high temperature of the combustion of the fuel.

Other objects of the invention will be apparent from the annexed specification and claims.

The nature and characteristic features of the invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which:

Fig. 1 is a, fragmentary vertical sectional View through' a steam generator in accordance with the present invention;

Fig. 2 is a transverse vertical sectional view taken approximately on the line 2--2 of Fig. 1;

and

Fig. 3 is an enlarged fragmentary sectional view of one of the hearth blocks taken approximately on the line 3-3 of Fig. 2; and

Fig. 4 is an enlarged fragmentary sectional view through the arch taken approximately on the line 4-4 of Fig. 1.

It should, of course, be understood that the description and drawings herein are illustrative merely, and that various modifications and ch'anges may be made in the structure disclosed without departing from the spirit of the invention.

Referring more particularly to the drawings the steam generator in accordance with the present invention includes a vertical front wall'Ill. a vertical rear wall II, and vertical side walls i2, Suitable transverse drums I3 and I3 are provided, the drum I3 serving as a lower water drum. Steam generating tubes I5 extending between the drum I3 and the drum I4 and banks of steam generating tubes I6 are provided extending from the drum I3 for steam generation in the customary manner.

The front wall I0 may also be provided with a transverse header I'I from which steam generating tubes I8 lining th'e front wall Ill extend upwardly to the drum I 4 and preferably also it may have a lower section Ia adapted to function as a heat absorbing and reflecting wall.

to provide apparatus for burning fuel for steam .30

As the foregoing structure is well known this description should sulce.

The steam generator is provided with a combustion chamber 20 to the rear of the front wall I0 and the combustion chamber 20 has a bottom Wall or oor 2| of peculiar construction which is preferably closed tov provide a h'earth space, as hereinafter more fully pointed out. The front wall I0 of the combustion chamber 2l] may be provided with one or more openings 22 for the introduction of fuel, such as anthranes, powdered bituminous coal or other fuel, preferably air borne, delivered through a pipe 23 from a mixer or servicer 24 of a type commonly employed for delivering air fuel mixtures to steam generators and which must be capable of projecting solid particles of fuel rearwardly into the combustion chamber 20 as hereinafter pointed out.

Above the h'earth or floor 2| a forwardly and upwardly extending arch 25 is preferably provided. The arch 25 is preferably constructed of a plurality of tubes 25 extending forwardly and upwardly with a slight inclination from a lower transverse header 21 then upwardly and rearwardly as at 21a, to an upper transverse header 28. The header 23 is preferably connected to the drum lli by a, bank of tubes 29. The tubes 26 of the arch 25 serve to support suitable refractory blocks Sil, U shaped in transverse cross section a's illustrated in Figs. 2 and 4. The blocks 30 rest on and are supported by adjoining pairs of tubes of the arch tubes 26. Each of the blocks 30 has a plurality of openings 3l at the lower part thereof for delivery of air downwardly as hereinafter pointed out.

The space above the arch blocks 30 and between the header 2'I and the header 28 is preferably closed at the top by a suitable wall or baie 32 and is divided by a plurality of partition walls 33 into air supply chambers 34 and the pressure of the air to these chambers 34 may be regulated, for purposes to be explained. The forward blocks 30a of th'e arch 25 are also preferably provided with air deliveryopenings 3Ia for purposes to be explained. The side walls I2 of the steam generator are preferably provided with lower side wall headers 35 running from front to rear of the combustion chamber 20. The bottom wall or hearth 2l preferably consists of transversely extending hearth blocks 36 carried on transverse tubes 3l beneath the combustion chamber 20 and connecting the headers 3 5. These tubes 3l in addition to their function of absorbing heat released by the combustion also cool and prolong the life of the hearth blocks 36. The hearth blocks 36 are preferably of carborundum or other suitable material to which the ash released by the combustion of th'e fuel is nonadherent. The hearth blocks 36 are so constructed as to be swingable on pivots provided by the tubes 31 for discharge of the ash released by the combustion of the coal. For the purpose of oscillating the hearth blocks 36 downwardly extending actuator levers 38 are provided, the actuator levers 38 being connected to actuator bars 39. A closed hopper or ash' pit 40 is provided beneath the hearth 2| to which the ash is delivered for discharge through an ash gate 4| at the bottom thereof.

The side Walls I2 are also provided with banks of steam generating tubes 42 extending from the lower side wall headers 35 to the drum I4, and banks of steam generating tubes 43 extending from the headers 35 to the front wall header Il.

The operation of the steam generator in accordance with the present invention will now be pointed out. Fuel is delivered to the Servicer 24 in finely divided form. This fuel may consist of powdered anthracite coal or anthracite culm, also known as anthrafines, or may consist of any other combustible matter in solid particle form. The fuel is entrained at the servicer 24 in a stream of y air and delivered through the front wall I2 of the combustion chamber 20 substantially horizontally or at a slight downward inclination towards the rear end of the hearth 2|. The quantity of air delivered With the fuel is the minimum required for purposes of delivery and is not suicient for maintaining combustion in the combustion chamber 20. As the particles of fuel are impelled into the combustion chamber 20, the lighter particles are caught by the advancing stream of gases of combustion and immediately ignited and burned. The larger particles of fuel by reason of their velocity are impelled towards the rear of the combustion space 20 and the largest particles, by reason of their velocity and greater mass, are delivered to and towards the rear of the combustion chamber 20. The fuel particles are thus distributed on and over the hearth 2| from front t rear with the larger particles delivered closer to the rear andv also so that they are closer to the arch 25.

The principal supply of air for combustion is delivered to the chambers 34 and 34a above the arch 25 and the pressure in the chambers 34 and 34a is preferably regulated as desired for maintaining a controlled iiow from the respective chambers 34 through the openings 3| in the arch blocks 30. The regulation of the pressure permits the control of the combustion conditions on and above the hearth 2|. The air is delivered downwardly through the openings 3| towards the fue] delivered to and collected on the hearth 2|. The air impinging on the fuel being delivered to the hearth 2| effectsthe ignition and combustion of portions of the fuel during its travel and also effects the ignition and the combustion of the fuel resting on the hearth 2| after its delivery.

The arch 25 will reach and remain at a high temperature and aid in maintaining ignition of the fuel as the same is continuously introduced. The air delivered through the openings 3 la from the chamber 34a aids in completing the combustion of the hot gases passing from the hearth 2| prior to their contact with the tubes I5 of the steam generator. The heat released by the combustion of the fuel is available as radiant heat for generating steam-in the side wall tubes 42 and 43 and in part in the arch tubes 26. The arch tubes 26 also serve to prevent the destruction of the arch blocks 30 and provide a longer life for these blocks.

I claim:

1. In a steam generator, a combustion chamber having side walls and a closed bottom wall providing a hearth, headers extending along said side walls, and spaced horizontal tubes connecting said headers, said bottom wall including hearth blocks supported on said tubes, and means for oscillating said hearth blocks for permitting the discharge of ash therebetween.

2. In a steam generator, a combustion chamber having side walls and a closed bottom wall providing a hearth, horizontally disposed headers extending along said side walls, spaced horizontal tubes connecting said headers, said bottom wall including movable hearth blocks supported on said tubes, and means connected to said hearth blocks for moving the same for permitting the discharge of ash therebetween.

3. In a steam generatory a combustion chamber having Side walls and a closed bottom wall providing a hearth, horizontally disposed headers extending along said side walls, and spaced horizontal tubes connecting said headers, said bottom wall including hearth blocks pivotally supported on said tubes, and means for oscillating said hearth blocks for permitting the discharge of ash therebetween.

4. In a steam generator, a combustion chamber having side walls, a closed bottom wall providing a hearth, and an arch above said hearth, means for projecting fuel into said chamber and onto said hearth, said arch including a bank of spaced tubes, and arch blocks carried on said tubes, said arch blocks being provided with openings for the discharge of air towards said hearth for the combustion of fuel delivered by said fuel projecting means.

5. In a steam generator, a combustion chamber having side walls, a closed bottom wall pro-I viding a hearth, and an arch, means for projecting fuel into said combustion chamber and onto said hearth, said arch consisting of an upper header and a lower header, a bank of tubes connecting said headers, and arch blocks carried on said tubes, said arch blocks being provided with openings for the discharge of air towards said hearth for the combustion of fuel delivered to said hearth.

6. In a steam generator, a combustion' chamber having side walls, a closed bottom wall providing a hearth, and an arch extending forwardly above said hearth, means for projecting fuel into said chamber and onto said hearth, said arch consisting of an upper header and a lower header, a bank of spaced tubes connecting said headers, and arch blocks carried on said tubes, the space above said arch blocks being divided into a plurality of chambers for delivery of air at diilerent pressures, said arch blocks being provided with openings for the discharge of air towards said hearth for the combustion of fuel delivered to said hearth.

- 7. In a steam generator, a combustion chamber having side walls, a closed bottom wall providing a hearth, an arch extending forwardly above said hearth, means for projecting fuel into said cham-` ber and onto said hearth, said arch consisting of an upper transversely extending header and a lower transversely extending header, a bank of spaced tubes connecting said headers, and arch blocks carried on said tubes, said arch blocks a bank of 'spaced tubes connecting said headers and arch blocks carried on said tubes, the space above said arch blocks being divided into a plurality of chambers for delivery of air at different pressures, said arch blocks being provided with downwardly directed openings for the discharge of air towards said hearth for the combustion of fuel delivered to said hearth.

J OI-IN PHILLIPS BADENHAUSEN.

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