US1312916A - Process -oe promotino - Google Patents

Description

E. C. LlLLlE.

PROCESS 0F PROMOTING COMBUSTION.

APPLICATION FIL-ED MAY 16. 1916.

Patented Aug. 12, 1919.

82f SHEETS-SHEET l.

E. C. LILI IE.

PROCESS 0F PROMOTING COMBUSTION.

APPLICATION FILED MAY I6, 19H5.

1,312,916, Pantedmlg. 12,1919.

2' SHEETS-SHEET 2.

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EDWIN C. LILLIE, OF DENVER, .COLORADO Pnocnss .or piaci/forma coiiisiisifroiv.

Specifcationpf Letters Patent.

Patented Aug.. 12,119,119.

Application filed May 16, 1916 Serial No. 97,828.

To all whom t may concern Be it known that I, EDWIN C. LiLLin, a.

citizen of the United States, and a resident of Denver, in the .county of' Denver and State of Colorado, have invented a certain new and useful Process of Promoting Combustion, of which the following is a full, clear, and exact description.

My invention is an improvement in methods of burning fuel andits objects are the utilization of all the heat units .in the fuel through complete combustion of its oxidizable constituents, including the gases, and the consequent elimination of smoke, Vlhile its principles are of general applicability my invention contemplates more particularly the provision of a process'by which fine, slack or other low grade coal may be burned eiiciently andwithout. smoke under steam or hot water heating boilers; and it is in connection with a couple of different types of installations for this purpose that I have illustrated and shall describe it though I do not wishto be considered as limited to the application selected or to the type of installation illustrated. further than the appended claims may indicate.

I have discovered that smokeless and complete combustion of coal may be had (even in connection with boilers for domestic heating where attention can `be given the lire only at long intervals) provided that the volatile hydrocarbons, free carbon, and carbon monoxid liberated or generated during the process of burning shall be expelled slowly and directly into and thoroughly and intimately mixed with a flame resulting from the combustion of the fixed carbon content of the fuel and in the presence of an excess of oxygen. As an aid in'attainin'g these conditions I maintain a relative deep body of fuel, only the lower portion of which is at the ignition temperature. Ignition of the entire column of' fuel may be prevented either by the nature of the fuel bed, it being sodeep and ne that gases can not pass .up through it imder the `draft conditions inamtained, or by inclosing the upper portion. of the fuel body in a closed chamber on which no draft is maintained, the distillates and products of combustion finding an exit only below the lower' edgesl of said chamber. As

A a further aid in attaining the proper conditions I limit tliebreadth of the fuel bed to `such dimensions that gases may be readily drawn therefrom laterally and I have found that a maximum path of substantially five inches to the nearestpoint of escape from the bed of fuel furnishes, so far as is now" known to me, a proper dimensioning of parts.

`Furthermore, to completely realize the conditions set out above the combustible gases which escape from the fuel must encounter a current of excess oxygen and be intimately mixed therewith at a temperature sufficiently high to produce the combustion thereof, and this encounter and admixture should take placel as quickly as possible after the liberation of the gases-when they are as nearly nascent as may be. In the two structures which I have illustrated in the accompanying drawings as being adapted to carry out the process, these means are provided in slightly different manners. In the form shown in Figures l, 2 and 3 there are provided a series of small, vertically extending, combustion chambers formed in the fire pot walls, these chambers having restricted openings communicating with the fire pot throughout their height, being open at the bottom for the entrance of an upwardly moving column of air and providing means at the top for the escape of their containedl gases to the stack. In the furnace shown in Figs. 4 and 5 the fuel is contained in a closed top fuel chamber vopen at its sides near the bottom; and at the sides of the fuel pot so constructed there are arranged a plurality of Water tubes affording restricted passages between them, said restricted passages constituting the co-mbiistion chamber of this type of boiler. The spaces between these tubes at the bottom afford openings for the admission of the upwardly passing current of air and the corresponding spaces at the top allow the products of combustion to escape to a space above the closed top fuel chamber and ultimately to the stack.

In the two sheets of drawings accompanying this application and forming a part hereof- Fig. l is a central vertical section through one type of furnace and boiler adapted to carrying out my` invention; l

Fig. 2 is a horizontal section through the half of the furnace and boiler shown in Fig. 1 taken on the line 2-2 of that ligure;

Fig. 3 is a vertical section on the line 3-3 of Fig. 2;

Fig. 4 is a transverse vertical section through a different design of furnace adapted to carrying out my process, the line on which this section is taken being indicated by the line 4 4 of Fig. 5; and

Fig. 5 is a central, longitudinal, vertical section of the furnace shown in Fig. 4, taken on the line 5-5 of that figure.

Reference may now be had particularly to these drawings, in order that the structures there illustrated as adapted to the carrying out of my invention may be thoroughly understood. In the furnace and boiler shown in Figs. 1, 2 and 3 let 6 represent a series of intermediate transverse boiler sections inter posed between front and rear sections 7 and 8, all of said sections being connected by upper and lower rods 9 and 10 which are secured in position by nuts 11 applied to their exposed extremities. These sections are all hollow to contain the water to be heated, provision for the circulation of which is made in the manner customary in such constructions. The sectionsare further so constructed and arranged that a lire pot 12 is formed in the lower part of the space inclosed by the several sections. The side walls of the sections, and the end walls as well if desired, throughout the chamber formed between their vertical water legs, are provided with vertical combustion flues or chambers 13 which are in communication with the space inclosed by the sections throughout their lengths by restricted openings 14 as shown and which are open at their bottoms to the ash pit. Pivoted normally open dampers 15 (Fig. 3) form means for closing the bottoms of these combustion chambers when desired.

The bottom of the re pot 1 2 is closed by a grate 16 which may be of the customary shaking type as shown. The numeral 17 indicates the firing door, which it will be observed 4is high, and 18 indicates the stack to which the products of combustion m escape from the top of the fuel chamber after hav ing entered the same from the restricted combustion chambers 13 through the portions of the openings 14 above the fuel bed.

In Figs. 4 and 5 l have illustrated what may be termed a water tube construction in which the cored out combustion chambers of the preceding construction are replaced by narrow spaces between the tubes. ln this setting there are provided a number of sections closely resembling the usual type of radiator sections, each having two legs with an open space between, the several sections being connected at the top and bottom for the circulation of water and the several sections being spaced slightly one from the other as indicated in Fig. The customary cold or return pipe 21 and steam or hot water pipe 22, leading if desired from a drum 23, are provided, these details of construction forming no part of the present invention.

The fuel chamber 24 is partially inclosed by a closed top and open bottomed casing 25 which stops as indicated some little distance above the grate 26, thus necessitating that the distillates and products of combustion in escaping from the bed of fuel must proceed laterally and pass through the spaces between the sections 20 before finding their way to the stack 27. A chamber 28 above the top of the casing 25 forms a means of collecting the products of combustion after they have passed up between the sections 2O and conducting them t0 the stack 27 at the rear of the boiler. Such a boiler furnace is also preferably provided with an upper feed door 29 and a lower feed door 30 so constructed with engaging flanges that the lower door may not be opened except when the upper one has been opened. This prevents the lower door only being opened which is desirable as in the ordinary ruiming of the furnace after starting the bed of fuel always extends thereabove. The door 30 therefore is usually closed except when laying a new fire. A closed casing 31 resting on the base 32 serves to retain the products of combustion from lateral escape after their passage into the spaces between the boiler sections.

Upcmtz'on.

Referring first to the type of furnace and boiler shown in Figs. 1, 2, and 3, in starting the furnace a comparatively thin fire may first be laid on the grate and at this time the dampers 15 are preferably closed to increase the draft through the fire, which, until thoroughly started, burns in the ordinary manner with the products of combustion passing upwardly therethrough. After good lire is started much more fuel is thrown on so that the bed of fuel is practically impervious to the gases generated and the dampers 15 are opened to allow the draft to draw upwardly through the combustion chambers or fines 13 a supply of air Which is heated as it rises. The hydrocarbons which distil from the raw fuel when it reaches a certa-in temperature and any carbon monoxid resulting from incomplete combustion are drawn laterally through the bed of fuel to the most available combustion chamber 13 and there they meet a rising sheet of Haine from the combustion Of the fixed carbon in the lower portion of the bed of fuel mixed with an excess of oxygen supplied by the air drawn into the combustion chambers from the ash pit. The areas 0f the chambers heilig relatively small and the current of rising flame and oxygen which the gases meet being at substantially right angles to their path as Y they are drawn from the fuel bed, intimate admixture of the combustible gases with the flamesfand the oxygen carrying heated air takes place. The flames from the fixed carbon highly heat the mixture and the gases meet the oxygen so soon after their liberation as to be substantially in a nascent state;

- gradual and continuous instead of being sudden and intermittent as is always. the case when fresh fuel is thrown on a glowing fire. There is therefore ample opportunity y for the flames which result from the subsequent combustion of the fixed carbon in the active combustion zone mixing with and burning the gaseous constituents constantly being distilled olf in a higher Zone, and the temperature cf th at part of the fire which is consuming the fixed carbon is not lowered as is the case where raw fuel is thrown on a glowing lire.

In the use of the apparatus shown in Figs. 4 and 5 substantially the same operation is carried out. This apparatus, however, draws the distillates and other combustible gases from the fuel only below a certain line (the lower edge of the casing 25) and therefore if distillation takes place above that line the gases must travel down to escape into the combustion chambers constituted by the passages between the water tubes. For this reason a lire in this apparatus may require a little more frequent attention to maintain the proper working con-l ditions than obtains with the other apparatus. But coal of higher quality may be employed as imperviousness of the bed of fuel itself is not requisite since the casing 25 being closed at the top will effectually prevent any upward escape of gases. In this construction the interstices between the several boiler sections are so small as to prevent the fuel falling from its chamber thereinto and as to result in the intimate admixture between the combustible gases and distillates and the excess oxygen carrying fiame requisite to the proper carrying out of my process.

The combustible products arising fro-m a bed of fuel during combustion comprise distilled hydrocarbons, uncombined carbon, hydrogen from dissociated water vapor, and partially combined carbon (CO) and in the claims have employed the term combustible gaseous products to indicate any or all of the products named.

In the apparatus disclosed for carrying out my process there are shown no means for withdrawing the combustible gaseous products from the ends of the fuel bed though it will be evident that such means maybe utilized if desired. The expression laterally employed-in the claims as defining the direction `in which the gases are withdrawn should therefore beA interpreted to include endwise as well as side wise.

Having thus described my invention, what l claim and desire to secure by Letters Patent is 1. The hereindescribed processof promoting combustion which 'comprises maintaining a relatively deep. and narrow bed of solid carbonaceous fuel, withdrawing the combustible gaseous products from the fuel laterally and gradually iV and discharging them directly: into a rising column of flame carrying an excess of oxygen7 said llamebeing; that resultant from the combustion of the fixed carbon of the fuel, Vand the fuel bed being so proportioned that said combustible 'gaseous products are `not required to travel more than about five inches through the fuel before being discharged into the rising flame column.

2. The herein described process of promoting combustion which comprises maintaining a relatively deep and narrow bed of solid carbonaceous fuel with only the lower portion thereof in a state of ignition, withdrawing the combustible gaseous products from the fuel laterally, gradually and directly into a rising column of flame carrying an excess of oxygen, said flame being that resultant from the combustion of the fixed carbon of the fuel.

3. The herein described process of promoting combustion which comprises maintaining a relatively deep and narrow bed of solid carbonaceous fuel with only the lower portion thereof in a state of ignition, preventing the escape of the combustible gaseous products upwardly through said fuel, withdrawing said combustible gaseous products from the fuel laterally, gradually and directly into a rising column of flame carrying an excess of oxygen, said flame being that resultant from the combustion of the fixed car-bon of the fuel.

4:. The herein described process of promoting, combustion which comprises maintaining a relatively deep and narrow bed of solid carbonaceous fuel with only the lower portion thereof in a statel of ignition, the depth and nature of said fuel bed being such as to prevent the passage of gases upwardly therethrough, withdrawing the combustible gaseous products from the fuel laterally, gradually and directly into a rising column of flame carrying an excess of oxygen, said flame being that resultant from the combustion of the xed carbon of the fuel.

5. The process of promoting-combustion which comprises maintaining active combustion in a lower zone of a substantially vertical column of solid carbonaceous fuel while substantially preventing escape of gases from the upper end of said column, supplying an excess of oxygen to the iames issuing laterally from the zone of active combustion of said solid fuel, and guiding the mixture upwardly and into contact with combustible gases issuing laterally from the fuel column above the zone of active combustion.

6. The process of promoting combustion which comprises maintaining active combustion in only the lower portion of a relatively deep and narrow column of solid carbonaeeous fuel While substantially preventing escape of gases from the upper end of said column, supplying an excess of oxygen to the flames issuing laterally from the region of active combustion of said solid fuel and guiding the mixture upwardly and into contact with combustible gases issuing laterally from the fuel column above the region of' a'ctive combustion.

7. The process of promoting combustion which comprises maintaining active combustion at one end portion only of a column of solid carbonaceous fuel While substantially preventing escape of gases from the other end of said column, supplying an eX- eess of oxygen to the flames issuing laterally from the region of active combustion of said solid fuel, and guiding the mixture along the outside of said column and into Contact with combustible gases issuing laterally from an intermediate portion of said column.

In testimony whereof I have hereunto affixed my signature.

EDWIN C. LILLIE.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.

` Washington, D. C.

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