US1701854A - Method of assisting combustion in furnaces - Google Patents

Description

Feb. 12, 1929.

G. P, JACKSON METHOD OF ASSISTING COMBUSTION IN FURNACES Original Filed March 29, 1922 2 sheets-sheet 1 I N V EN TOR.

4 K415 F JIc/(soN Feb. 12, 1929. 1,701,854

G. P. JACKSON METHOD OF ASSISTING COMBUSTION IN FURNACES Original Filed March 29. 1922 2 Sheets-Sheet 2 INVENTOR. Q EQ 'Jivc/rao/v A TTORNEYS.

Fates-fled Feb. 12, 1229.

PATENT OFFICE.

enonen r. .racxson, or rnusnrim, NEW

YORK, ASSIGNOB TO INTERNATIONAL COI- BUSTION ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION 01' DELAWARE.

METHOD OF ASSISTING COMBUSTION m FURNACES.

Original application filed March 29, 1922, Serial No. 547,878. Divided and this application filed June 8, 1925. Serial No. 35,297.

The present invention has special reference to a method of assisting combustion in a furnace, and reducin liability of clinkers and other injurious eposits forming on 6 the wall of the fire-box of a furnace.

An object of the invention is to rovide a novel and improved method of t is character which is particularly adapted for use in a pulverized fuel furnace.

The several features of the invention, whereby'the above mentioned and other objects may be attained, will be clearly understood from the following descri tion and accompanying drawings, in whic Figure 1 is a longitudinal vertical sectional view, partly in elevation and in part diagrammatical, of a pulverized fuel furnace which is particularly adapted for use in carrying out my improved method;

Fig. 2 is a sectional plan view taken on the line 22 of Fig. 1;

Fig. 3 is a vertical sectional view taken on the line 33 of Fig. 1;

Fig. 4 is a sectional elevation, on an enlarged scale, taken on the line 4:-4/ of Fig. 2;

' Fig. 5 is a detail inverted view in perspective of a component part of the bed or bottom of the fire-box;

Fig. 6 is a transverse sectional view, on an enlarged scale, taken on the line 6-6 of Fig. 2; and

Fig. 7 is a detail inverted view in pers c tive of a component part of the bed or ttom of the fire-box.

The pulverized fuel furnace illustrated in the drawings may be and preferably is the same as the one described and claimed in my pending application Serial No. 547,678,

filed March 29, 1922, of which the present application is a division. As shown this furnace is provided with a steam boiler 2, and a fireox 4 having longitudinal side walls 6, front wall 7, rear or bridge-wall 8 and a top wall 10. A pulverized fuel nozzle 12, suitably connected with a source of fuel supply, is mounted in the top wall and is so arranged as to direct-pulverized fuel downwardly into the fire-box. In this type of furnace the combustion of the fuel takes place while the fuel is in suspension and the furnace draft tends to direct the suspended mass of burning fuel and the gases upwardly to the boiler as indicated in Fig. 1 of the drawings.

As illustrated the fire-box is provided with two piers 14 which are arranged on the bottom wall 15 of .the fire-box and adjacent the side walls 6, respectively. The fire-box is' further provided, on its bottom 60 wall with a series of three piers 17, the outer piers of the series being spaced from the piers 14 and from the intermediate pier of the series, said spaces between the iers forming troughs. The front wall 0 the fire-box is provided with openings 18 at the forward ends of the trough which are closed by doors 1 9.

Each of the piers 17 consists of side walls 20 and an intermediate partition22 which is spaced from the side walls, these arts of t e piers being made of fire-brie The top. of each pier 17 consists of blocks 24 of refractory material that are arranged in end to end relation and rest upon and are cemented to the tops of the side walls 20 and the intermediate partition 22 with the longitudinal sides of the blocks rojecting bey lond the outer surfaces of t e side walls. ach block is made in two oppositely disposed sections having their inner ends abutting each other in a. vertical plane The upper portion of the inner ends of the sections of each block are provided with oppositely disposed right angle grooves or channels 25 forming a channel extending the length of the block, with said channels of the series of blocks of each pier 17 forming a channel 26 that extends the length of the pier. The inner abutting ends of the block sections are provided with oppositely disposed vertical channels 28 formin squared air ducts leading into the channe 26. The bottom sides of the block sections are provided with oppositely disposed transverse channels 30 that form continuations of said vertical channels 28. The inner or upper walls 32 of the channels 30 are inclined upwardly and inwardly. The block sections are provided with vertical longitudinal sides 34, and top sides or sur; faces 36 that incline upwardly from the vertical sides 34 to the vertical walls of the longitudinally extending channel 26. The

. channel 26 of each ier- 17 is covered by cap blocks 38 of re ractory material that rest on and are cemented to the top of the blocks 24 and are arranged end toend in staggered relation to the blocks 24. The

under sides of the cap blocks 38 are provided with a horizontal longitudinally extending central portion 40 of substantially the width of the channel 26, and with outer inclined portions 42 that -fit the inclined top surfaces 36 of the block sect-ions. The under sides of the caps are also provided with shallow transverse channels'44 which when hollowed out to form an air chamber 46 which is connected at its lower end with a suitable source of air supply by a pipe 48. The air chamber 46 is in communication with the spaces between the intermediate partition 22 and the side walls 20 of each pier 17 through branch air passages 50.

The two outer piers 1'4 correspond to the portions of a pier 17 on opposite sides of a vertical lane extending through the center of the pler 17 each pier 14 having an outer side wall 20' corresponding to the wall 20 of the piers 17, an inner wall 22' corresponding to one half of an intermediate partition 22, a channel block 24 corres onding to a section I of one of the b ocks 24, a series of channeled caps 38' each corresponding to one half of one of the caps 38, andv an air duct 50 in the bridge wall 8 leading from the air chamber 46 into the space between the outer wall 20 and inner wall 22' of each pier 14.

With this construction it will be apparent that upon air being admitted from the 'air chamber 46 to the spaces between the side walls and intermedlate partitions of the piers 17 and between the walls 20' and 22 of the piers 14, the channel caps 38 and 38 will direct a portion of the air in thin films over the inclined top surfaces .36 of the blocks 24 and 24 and downwardly towards the troughs between the piers, and also that the air passages formed by the channels 30 in the under side of the block sections will direct thin fihns of air outwardly from the piers in a horizontal plane across the troughs. The air thus directed by the chanwill maintain the caps below clinker forming temperature and as the upper longitudinal edges 52 of the caps overhang the ends of the channels 44 in the caps there will be no danger of clinkers or slag forming on these edges. As the longitudinal sides 34 of the blocks 24 and 24 project beyond the outer surfaces of the side walls ofthe piers there is no danger of the trans verse channels 30 becoming clogged by clinkers forming over their outer ends. As the air passes over the outer edge of the inclined surfaces 36 of the blocks 24' and 24 the furnace draft will tend to cause the air to pass upwardly toward the burning fuel and such tendency of this air to pass upwardly will be increased by the horizontal films of air passing through the horizontal channels 30 in the blocks, the horizontal films of air tending to break up the films of air passing over the inclined surfaces 36.- Thus the films of air passing from the interior of the piers will be drawn up through the furnace by the furnace draft which Wlll aid combustion and also tend to hold in suspension the heavier particles of fuel not completely burned that would ordinarily fall to the bottom of the furnace. These heavier particles will thus be more completel burned before finally settling in the troug s between the piers.

From the foregoing it will be apparent that all of the cinders and other refuse from the burning fuel will settle in the troughs and that it may be easily removed from the troughs through the openings 18 that are closed by the doors 19. The construction of the piers is such as" to provide for the admiSSIOH of air into the fire-box through the bottom thereof without danger of the air passages becoming blocked or clogged.

The four vertical walls of the fire-box of the illustrated construction is provided with three rows of blocks 54 having downwardly and inwardly inclined air ducts 56 in communication with the air chamber 46. These air ducts are arranged to direct films of air downwardly over the surface of the firewall and below the mass of burning fuel and inwardly toward the fuel. As the air thus passes below the mass of burning fuel the furnace draft draws the air inwardly and upwardly through the furnace to cooperate with the air rising from the piers 14 and 17 to aid combustion and to assist in holding the heavier particles of the burning fuel in suspension. .It will be apparent that the downward admission of air from the front and side walls of the fire box of the furnace would tend to cause the heavier particles to take a long travel through the combustion chamber, and the more or less horizontally directed streams at the bottom of the combustion chamber would tend to prevent the heavier particles from being forced to the bottom. The construction and arrangement of the blocks 54 are described and claimed in my copending application filed of even date herewith.

As will b e-evident to those skilled in the art my invention permits various modifications without departing from the spirit thereof or the scope of the appended claims.

What I claim is:

1. The process of fine fuel combustion which comprises feeding downwardly into a combustion chamber a stream of a1r and fine fuel," and also introducin at a lower level and at one side of the lel stream a downwardly directed flow of supplemental air under pressure, and adjacent the lower ortion of the chamber introducing substailtially horizontally another flow ofsupf plemental air under pressure.

f 2. Method of ,burning pulverized fuel which consists in introducing into a combustion zone havin a draft outlet, fuel and air ina downwar 1y projected stream, so that the fuel in combustion takes a return bent course to the draft outlet, introducing air under pressure into the combustion zone as a thin laterally extended stream directed downwardly at one side of the path of the fuel and also introducing 'air under pressure into the combustion zone in a thin laterally extended stream directed horizontally mitting the fuel in an upper art of the chamber-so that the fuel and ame stream reverts on itself in a substantially .U-for'm, introducing at a lower level and at one side of the fuel and flame stream a downwardly directed flow of air, and introducing adjacent the lower portion of the chamber substantially, horizontally another flow of air.

4. The method of burning fuel in suspension in a combustion chamber havingvan outlet in an upper part, which includes admitting the fuel in an upper part of the chamber so that the fuel and flame stream reverts on itself in a substantially U-form, introducing air into the chamber as a thin laterally extending stream directed downwardly at one side of the path of the fuel and flame stream, and also introducing air into the combustion chamber in a thin laterally extended stream directed horizontally beneath the fuel and flame stream.

In testimony whereof, I have si ed my name to this specification this 2n day of June, 1925.

GEORGE P. JACKSON.

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