US510788A - hawkins - Google Patents

Description

no Mode1 F. H. HAWKINS.

. PULVERIZED FUEL BURNER.

No. 510,788. Patented Dec. 12, 18 93.

UNITED STATES PATE T. OFFICE.

FREDERICK H. HAWKINS, on NEW YORK, N. Y.

PU LVERlZED-FU El. BURN ER.

SPECIFICATION forming part of Letters Patent No. 510,788, dated December 12, 1893.

Application filed March 27, 1893- Serial No. 467,835. (No model.)

To all whom it may concern.-

Be it known that I, FREDERICK H. HAWKINS, a subject of the Queen of Great Britain, residing at New York city, in the countyof New York and State of New York, have invented certain new and useful Improvements in Pulverized-Fuel Burners; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved apparatus for, and method of burning pulverized coal mingled with atmospheric air, to be used as a fuel in furnaces for steam boilers, and other places where a very high heat is required.

The prime object of the invention is to reduce the cost of operating a furnace or engine by employing a cheap coal which when pulverized and mingled with air, and fed to suitable burners in a fire chamber, will give a very high heat.

A further object of the invention is to subject such powdered or pulverized coal and the mingled air to the action of heat in a chamber or retort before it enters the burners or fire chamber so that as such mass reaches the point for ignition it will be in the form of a highly attenuated gas, or at least in a partly gaseous state, thereby making the combustion very rapid and the heat very intense.

Other objects and advantages will appear from the following description and claims, when taken inconnection with the annexed drawings, in which I have illustrated my apparatus in connection with a horizontal steam boiler, although it is obvious that other forms of boiler may be employed without departing from the spirit of my invention.

In the drawings: Figure 1, is a plan view of my improved apparatus with the boiler removed and the furnace walls in section, and also illustrating one type of a pulverizer and blower. Fig. 2, is a vertical longitudinal sectional view taken in the plane indicated by the dotted line w, x, on Fig. 1. Fig. 3, is a vertical transverse sectional view taken in the plane indicated by the dotted line y, y, on Fig. 1. Fig. 4, is a similar sectional view taken in the plane indicated by the dotted line 2, z, of Fig. 1, with the burners in position, and Fig. 5, is a sectional detail view of one of the transverse feed pipes, and one of the burners. together with the grate bars,

illustrating the refractory material upon the latter.

Referring by letter to said drawings: A, indicates a furnace which may be of any ordinary or approved construction, and B, indicates the bridge wall thereof.

0, indicates a boiler which is here shown as a horizontal boiler although it is obvious that other forms may be employed.

D, indicates the grate bars which may be also of the construction usually employed.

E, indicates a pulverizer, and F, a blower, connected with the pulverizer by means of a pipe or conduit a.

G, indicates a retort or chamber of a suitable capacity, and arranged just in rear of the bridge wall ofthe furnace. Leading from one end of this retort or chamber is a longitudinal pipe H, which connects at its opposite end with the blower as shown. This pipe H, is preferably arranged at an altitude to come. in contact with the heat in the combustion chamber or fire box, and passes through the front wall of said chamber as shown and along one of the inner side walls of the furnace. This pipe is designed to take the powdered or pulverized coal from the blower where it is mingled with air, and force the same into the chamber or retort G, where said pulverized coal and mingled air will expand and by the action of heat become highly attenuated and at least partly converted into a gaseous state. Leading from the opposite end of this retort or expansion chamber and at a less altitude than the pipe H, is a pipe I, which is designed to receive the fuel in thishighly attenuated condition and conduct it to feed pipes or tubes K. These feed pipes or tubes K, are arranged transversely within the fire chamber at a suitable distance below the grate bars and are provided with a suitable number of apertures 17, at intervals along their upper sides as shown so that the pulverized or ground fuel and mingled air, as it is taken from the retort or expansion chamber, will be discharged into the transverse feed pipes or tubes, and from there through the apertures b.

Arranged over each aperture 1), in the feed pipes or tubes is what is known as a Bunsen burner c. In some cases other forms of burners might be employed but I prefer the use of the Bunsen burner as it will aid materially in drawing up any air which might be in the ash box or below the grate. These burners comprise a base section d, which is of a truncated cone shape, and an upper section 6, placed with its large end upon the top of the base section, with a space between the adjacent ends to admit the passage of air upwardly. These burners are arranged below and between the grate bars with their outlets slightly above the grate bars, as shown. It is designed to place the refractory material as shown by L, in Fig, 5, upon the grate bars. I have not given any detail description of the construction of blower or pulverizer, as they form no part of my invention, and while I have shown these devices as provided with pulleys to receive drive belts, yet they may be operated by any suitable motive power.

In operation, after the refractory material has been placed upon the grate bars, and the pulverized coal has been mingled with air, it is forcibly carried by means of the pipe II, into the retort or expansion chamber G, where it will quickly expand as it becomes heated, and from thence it is carried out at the opposite end of said retort by means of the longitudinal pipe I, where it is distributed through the feed tubes K, and thence fed to the burners c, where ignition takes place, and the refractory material becoming incandescent, a Very high and intense heat will be had.

Having described my invention, what I claim is- 1. The method of burning pulverized coal and mingled air, consisting first in mingling the pulverized coal with air, then heating and expanding such commingled mass, in a retort constituting an expansion chamber and finally carrying off the heated and attenuated mass to burners and igniting the same, substantially as described.

2. The combination with a furnace or fire chamber; of a retort constituting an expansion chamber, arranged so as to be heated by the furnace fire, means for charging the retort and expansion chamber with commingled air and comminuted coal, and a conduit or conveyer connecting the retort and expansion chamber with the furnace chamber and adapted to receive the fuel from said retort and expansion chamber and discharge the same into the furnace chamber, substantially as described.

3. The combination with a furnace or fire chamber; of a retort or expansion chamber arranged therein, a pipe leading from one end of said expansion chamber, branch pipes leading laterally therefrom beneath the grate bars and provided with apertures on their upper sides, burners arranged over the apertures, and a pipe leading from the opposite end of the retort or expansion chamber and adapted to receive pulverized coal mingled with air, and feed the same, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

FREDERICK H. HAWKINS.

Witnesses:

L. A. HAYWARD, E. LAMKIN.

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