US1228769A - Apparatus for burning powdered coal. - Google Patents

Description

A. J. GRlNDLE.

APPARATUS FOR BURNING POWDERED COAL.

APPLICATION FILED FEB-15.1916.

LQ28,7@9a Patented June 5, 1917.

3 SHEETS-SHEET 1- jwwemm A. JAGRINDLE.

APPARATUS FOR BURNING POWDERED COAL.

APPLICATION FILED FEB. 15, 1915.

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APPARATUS FOR BURNING POWDERED COAL.

APPLlCATlON FILED FEB. I5. I916.

Patented June 5, 1917.

3 SHEETSSHEET 3- AUBREY J. GRINDLE, OF CHICAGO, ILLINOIS, ASSIGNOR T0 COMBUSTION ECONOMY ('1OIEtIEORATION, OF CHICAGO,

ILLINOIS, A' CORPORATION.

APPARATUS FOR BURNIN G POWDERED COAL.

naaa'ma Specification of Letters Patent.

Patented June 5, 191?.

Application filed February 15, 1916. Serial No. 78,372.

To all whom it may concern:

Be it known that I, AUBREY J. GRINDLE, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illi: nois, have invented certain new and useful Improvements in Apparatus for Burning Powdered Coal, of which the following is a specification, and which are illustrated in the accompanying drawings, forming a part thereof.

The invention relates to an apparatus for generating heat by the combustion of comminuted solid fuel. The objects of the invention are to provide for a regulated delivery of the fuel and its uniform admixture with air for combustion and to avoid objectionable accumulations of the melted fuel ash in the furnace.

In the accompanying drawings,

Figure 1 shows an improved form of furnace provided by the invention, the parts being principally shown in transverse section but the burners and certain of the fuel feeding elements being shown in front elevation.

Fig. 2 is a sectionalview taken on the line 2-2 of Fig.1, some of the parts being shown in elevation,

Fig. 3 is a detail sectional view drawnto a larger scale showing a form of burner which may be used in connection with the invention,

, Flg. 4 1s a central sectional view drawn to a larger scale and showing the fuel feeding apparatus,

Figs. 5 and 6 are sectional details both taken on the plane indicated by the line 5-5 on Fig. 4 but showing the parts as they appear when viewed in opposite directionsfrom said plane,

- 7 Fig. 7 is an enlarged sectional view show- 111g details of the mixing apparatus, and p Fig. 8 is a sectional view taken on the line 8-8ofFig.7

In carrying out the invention the comminuted fuel is injected with air into the combustion chamber, as 10, of a furnace which may take the form shown in the drawings, and generally designated by the numeral 11. The combustion chamber 10 preferably has a masonry floor, as 12, and this floor is apertured for the discharge of melted slag, as at 13, 14, and 16. When a plurality of burners, as 17, 18, 19 and 20,

are provided for the injection of the fuel surfaceof the plates. At its with air, the said apertures in the floor 12 are preferably equal innumber to the number of such burners. In the arrangement shown the burners 17, 18, 19 and 20 are arranged in a transverse row and each is directed vertically into the chamber 10 through an opening 21 in the roof 22. Under these circumstances, the apertures, as 13,

.14, 15 and 16, in the floor 12 are conveniently I so located that one of said apertures is in vertical alinement with each of the burners.

Access to the floor 12 of the combustion chamber for the application and occasional renewal of a protective'covering 23 of loose material upon said floor about the apertures, as 13, 14, 15 and 16 is permitted by the provision of a door 25, on one of the Walls, as 2-1, of the furnace. The other walls, as 26 and 27 of the furnace will usually be eX- tended rearwardly beyond the combustion chamber 10 at each side and a bridge wall 28 may extend transversely between said walls in the customary position, the space 29 above and beyond said bridge wall constituting a flue for conveying the heated prod nets of combustion to the partto be heated.

The furnace 11 is further constructed to provide a pit 30 below the floor 12 and supplemental flues, as 31 and 32, for carrying away that portion of' the products of combustion which passes through the apertures,.as 13, 14, 15 and 16 in said floor.

' Suitable provision is made in-the pit 30 for accommodating I the accumulations of slag which are discharged from the combustion chamber through the apertures, as 13, 14 15 and 16 in the floor 12. In the arrangement shown, a pair of inclined plates 33 and 34 are provided and these plates slope downwardly in opposite directions from the center line of the furnace, form ing a ridge alongwhich a pipe 35 is extended for delivering a chilling fluid upon the lower end each plate 33, 34, extends to and forms one of the walls of a Well, as 36 or 37 at the corresponding side of the furnace. -These wells preferably extend laterally outward through the side Walls 26 and'27 of the furnace, respectively, and the wells are sealed both for retaining a qu'antityof the chilling fluid and the accumulated slag and to prevent the admission" of air for diluting the products of combustion As shown, a cover plate 38, eXtendsoutwardly from each of the side walls of the furnace over the projecting part of the corresponding well, and a downwardly opening hinged door 39 serves for" closing the outer end of the well.

When water is to be employed for chilling the slag as it falls upon the plates 33 and 34, the pipe 35 is provided with a series of lateral openings 40 at each side over the corresponding plate, and each well 36 and 37 is equipped with an overflow pipe, as '41. If desired, this overflow pipe may be constructed as to also serve for draining the corresponding well when the door 39 is to"be opened for the removal of the accumulations of slag. As shown, each overflow pipe 41 takes the form of an elbow having one end rotatably mounted in a vertical wall of the corresponding well 36 or 37 for movement between the upright and horizontal positions indicated by dotted lines in Fig. 1. WVaterwhich is discharged by the overflow pipes 41, in either position may be received upon the floor, as 42 of the pit 30, in which case this floor preferably slopes downwardly from each side and is provided with a drain opening 43 at its center. As-it is desirable to protect the pipe 35 from the heat during the greater portion of its length, this pipe may be extended through one of the side walls, as 27, of the furnace, to the center line of the furnace in rear-of the bridge wall- 28,

and thence forwardly through a masonry filling as 44, between the flues 31 and 32. When the use to which the furnace is put is .not such as to render the admixture of steam resulting from the evaporation of water upon the plates 33 and 34 with the products of combustion, objectionable, the supplemental fines, as 31 and 32, may connect with the main flue 29 immediately in the rear of the bridge wall 28, as at 45, Fig. 2.

The comminuted fuel may be supplied from a hopper, as 46; In the arrangement shown a separate feeding mechanism and air supply is associated with each burner. The fuel feeding mechanisms are all of like construction and eaclrcomprise a feed screw 47 and a carrying air supply pipe 48. The feed screw 47 extends horizontallywithin a suit able depression, as 49, in the floor of the hopper 46, the spindle 53 of the feed screw being extended at one end through the corresponding wall of the hopper andthere pro vided with suitable mechanism for effecting the rotation of the screw at regulated speed, as the friction disk 50. The opposite side wall of the ,hopper 46 is shown asbeing formed into a discharge tube 51 for inclosing the corresponding end of the feed screw and a receiver 52 is'applied to the end of this discharge tube. The adjacent end of the spindle 53 of the feed screw is then ex tended through the receiver 52 and is conveniently j ournaled upon the outside all of the said casing. The carrying air supply pipe 48 communicates with the chamber of the casing 52. As shown a pair of oppositely facing alined nipples 54 and 55 are provided at the lower end of the receiver, one of these nipples, as 54, serving connection' with the carrying air supply pipe 48 and the other nipple, as 55, serving for the attachment of a pipe 56 through which the fuel impregnated carrying air is discharged.

A pair of relatively rotatable plates 57 and 58 serve for insuring a uniform regulated discharge of the fuel into the chamber of the receiver 52 by the feed screw 47. As shown, the plate 57 has acentral opening 59 'of the same size with the bore of the discharge tube 51 and this plate -is fixedly secured against-theinside wall'of the receiver about the end of the said discharge tube. The plate 58, on the other hand, ro-

V tates' with the feed screw 47 For'this pur-' pose it is fixed upon the spindle 53 of the feed screw immediately in front of the plate 57 Preferably the adjacent faces of the two plates 57 and 58 are formed with curved tive position. Preferably the forward end of the pipe 62 is connected with a downturned elbow 64 and the lower end of this elbow, is connected with the corresponding burner, as \19, by a' vertical pipe 63. The fuelimpregnated carrying air is united with the volume air by the extension of the pipe 56 into the elbow 64. As shown the extension of this last mentioned pipe into the elbow 64 is in the direction of, and axially disposed with reference to, the discharge of the volume air from the elbow into the pipe 63. The pipe 63 accordingly serves as a mixing chamber orcarbureter. The mixing of the fuel impregnated carrying air and the volume air may be improved, however, by the location of aplurality of mixing'devices 65 at intervals throughout the length of the pipe 63. Each of these mixing devices preferably comprises two sets of curved stationary blades 66 and 67, the blades of each set being radially arranged with reference t6 the axis of the pipe, and the blades of the two sets being inclined in opposite directions to the normal direction 'of the travel of the air through the pipe. As shown, the blades of one set, as 66, are confined to the inner' or central portion of the pipe while the blades of the other set, as 67, extendoutwardly from the outer ends of the blades 66. The two sets of blades accordingly tend to produce whirling movements in opposite directions of the interior and outer portions of the column of air in its travelthrough the pipe. Furthermore, the efi'ectiveness of the several mixing devices 65 is increased if the bladesof the corresponding sets are oppositely lnclined in adjacent mixing devices. The directionof the whirling movement imparted to the 1nterior and outer portions of the column of air and suspended fuel by the blades 66 and 67 of one mixing device are thereby referred construction, those shown being pro vided with means for regulating both the direction and the velocity of the air and fuel jet into the furnace chamber. each burner comprises a shell 68 which is of flattened shape in cross section and which flares in the direction of its length with the smaller end of the shell connected with the pipe 63 and the larger end of the shell fitted into the corresponding opening 21 in the furnace roof. A pair of plates 69 are mounted within the shell 68, each plate being hingedly secured along its inner edge upon one of the side walls of the shell. For adjusting the angular position of the plates 69, a pair of set screws 70 are extended through the side walls of the shell 68.

The provision of supplemental flues as 31, 32, under the floor of the combustion chamber 10, insures that aportion of the heated products of combustion will pass through the openings, as 13, 14, 15 and 16, in the floor l2 and thus prevent the freezing of the slag in and about these openings. In the event that it is desired to reduce the melting point of the slag, a quantity of flux, as limestone, may be added. This fluxmg material may be spread upon the floor 12 of the combustion chamber in a crushed condition or a quantity of the fluxing material in a powdered condition may be fired with the coal as by mixing it with the fuel in the hopper as 46. The provision of the rotating plate 58 at the forward end of the feed screw 47 prevents the delivery of compact masses of the fuel from the end of the feed screw into the chamber of the receiver 52. .An efficient, uniform and substantially continu- 1 ous operation of the furnace is thus permitted while the accumulations of slag in the wells, as 36 and 37 are in granular form and are easily removed through the doors 39, if the overflow pipes 41 be first arranged to discharge the entire fluid contents of the wells into the drain 43.

It will be understood that the movement of the carrying air from the nipple 54 across the lower end of the receiver 52 and into the nipple 55 serves to partially exhaust the chamber of the receiver. The receiver 52 floor, A simple construction of the To this end is accordingly. provided with a cover 71 which may be opened for the admission of air.

I claim as my invention,-

1. In a furnace in combination, a combustion chamber having a floor with an opening therein, a main flue leading out of the combustion chamber above its said a supplemental flue extending under the floor of the said combustion chamber and communicating with the said opening in the floor of the chamber at one end and with the first mentioned flue at the other end to form a by-pass through said opening to the main flue for a part only of the prodnets of combustion, a jet burner for comminuted solid fuel entering the combustion chamber and a receiver for the melted fuel ash below the said opening in the floor of the combustion chamber.

2. In a furnace, in combination, a combustion chamber having a floor with an opening therein, a main flue leading out of the combustion chamber above its said floor, a supplemental flue extending away from the said opening at the under side of the floor of the combustion chamber, a jet burner for comminuted solid fuel entering .the combustion chamber, and a receiver for the melted fuel ash below the floor of the combustion chamber in line with its said opening.

3. In a furnace, in combination, a combustion chamber having a pair of laterally separated openings in its floor, a pair of inclined walls below the floor of the combustion chamber, said walls facing laterally outward in opposite directions and each extending from the longitudinal median line of the furnace under one of the said open-- ings in the fioor of the combustion chamber, a pipe extending along the ridge formed by the meeting of the said two walls upon the median line of the furnace, said pipe having openings at each side for the dis? charge of a cooling fluid over the said two walls, a sealed well at each side of the furnace at the lower edge of the corresponding one of the said sloping walls, a flue extending out of the space between the floor of the combustion chamber and the said two sloping walls and a burner for comminuted solid fuel entering the combustion chamber.

4. In a furnace in combination, a combustion chamber having an opening in its floor, a sloping wall extending under the said opening in the floor of the combustion chamber, a sealed well at the lower edge of the said sloping wall, means for delivering a cooling fluid upon the said sloping wall adjacent its upper edge, a burner for comminuted solid fuel entering the combustion chamber and a flue leading out of the space between the underside of the floor of bustion chamber above its said floor, a sloping wall extending under the said opening in the floor of the combustion chamber, a

sealed well at the lower edge of the saidsloping wall, means for delivering a cooling fluid upon the said sloping wall adjacent its upper edge, a burner for comminuted solid fuel entering the said combustion chamber and a supplemental flue leading out of the space between the underside of the floor of the combustion chamber-and the said sloping wall.

6. In a furnace, in combination, a combustion chamber having a dished masonry floor with a drain opening through said floor at its lowest point, a main flue leading out of the combustion chamber above its said floor, a supplemental flue extending under the floor of the combustion chamber and communicating with the said drain opening and with the first mentioned flue to form a by-pass through the said drain opening to the main flue for a part only of the products of combustion and a jet burner for comminuted solid fuel entering the combustion chamber. I

7. In a furnace, in combination, a combustion chamberhaving a dished masonry floor with a drain opening through said floor at its lowest point, a main flue leading laterally out of the combustion chamber above its said floor, a supplemental flue extending under the floor of the combustion chamber and communicating with the said drain opening and with the first mentioned flue to form a by-pass through the said drain opening to the main flue for a part only of the products of combustion, and a jet burner for comminuted solid fuel entering the top of the combustion chamber and facing its said floor.

8. In a furnace, in combination, a combustion chamber having a sloping masonry floor with an opening through said floor at its lowest point, a jet burner for comminuted solid fuel entering the combustion chamber, a flue communicating with the said opening in the floor of the combustion chamber from below said floor, a receiver for the melted fuel ash below the said opening in the floor of the combustion chamber and means for delivering a cooling flui upon the said receiver. 9. In a furnace, in combination, a combustion chamber having a sloping masonry floor with an opening through said floor at its lowest point, a main flue leading out of the combustion chamber above its said floor, a supplemental flue communicating with the said opening through thefloor of the combustion chamber from below said floor to form a by-pass through said opening for a part only of the products of combustion, and a jet burner for comminuted solid fuel entering the combustion chamber.

AUBREY J. GRINDLE.

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