US1348561A - Controlliitg proportions - Google Patents

Description

- w. E. HARVEY. CONTROLLING PROPORTIONS 0F PULVERIZED FUEL MIXTURE.

' APPLICATION FILED MAR. 7, 1919. Patented Aug. 3, 1920.

2 SHEETS-SHEET 1.

W. E. HARVEY; CONTROLLING PROPORTIONS 0F PULVERIZED FUEL MIXTURE.

APPLI-CATION FILED MAR-7,1919. 1,348,561.

Patented Aug. 3, 1920.

2 SHEETS-SHEET 2.

nabv WITIMRSFS-ES INVENTOR UNITED STA S PATENT OFFICE.

WILBER IE. HARVEY, 0F GL ENSHAW, PENNSYLVANIA.

CONTROLLING PROPORTIONS 8F PULVERIZED-FUEL MIX'IURE.

Application filed March 7,

To all whom it may concern:

Be it known that I, VVILBER E. HARVEY, residing at Glenshaw,"in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Controlling Proportions of ,Pulverized-Fuel lWiXture, of which improyement the following is a specification.

My invention has to do with the art of burning solid fuel which. in a finely divided or pulverized state, is carried in suspension in a flowing stream ofcombustiohsupporting gas. While applicable to the burning of different kinds of pulverized combustible fuelmy invention finds particular adaptability to the burning of" coal dust suspended in air, and it is with reference to such particularuse that I will describe it.

In using, as a fuel for burners in a manufacturingplant, coal dust suspended in a stream of air, the usual practice is to reduce the coal to a pulverized condition at a crushing station at or near the plant,'and to mix the pulverized coal with a continuously flowing streamlof air under pressure. A main conduit for carrying the mixture of air and coal dust is extended to the parts of the plant at which it is desired to burn the fuel, and for. each burner or set, of burners a portion of the mixture is abstracted from the? main conduit and conducted to the burner by means of a branch conduit. The initial mixture is usually formed with an excess ofcoal dust, that is to say, the mixture does not contain sulficient air to effect complete combustion of the coal, andaccordingly additionalair is supplied to each burner by means of a' suitable blast.

For abstracting, for a burner, a pertion of the. mixture from the main conduit, the inlet end of the branch conduit is usually provided with a valve." It will be understood that such valve merely controls the amount ofa givenmixture'thatis permitted to flow through the branch conduit, or, in otherwords, that the valve does not have the efi'ect of varying the relative proportions of the mixture fed to a burner. Considerable difiiculty has been experienced in the use of such controlling valves in branch conduits by reason of the fact that they so obstruct the passage ofthe branch conduit that coal dust deposits in thebranch conduit and is frequently ejected in mass,

Specification of Letters Patent.

Patented Aug. 3 1920. 1919. Serial No. 281,287.

causing undesirable puffs in the flame, and, occasionally disastrous explosions.

The object of my invention is to provide means whereby variable relative proportions of a mixture of a combustionsupporting gas and combustible particles may be abstracted from a main conduit and fed to a burner through a branch conduit having an unobstructed passageway.

In the accompanying sheets of drawings, which form part of my specification, I have illustrated the preferred embodiment of my invention/ Figure l is an elevation of a plurality of -furnaces, a main conduit, and branch conduits extending from the main conduit to the furnaces; Fig.2 a vertical sectional view taken on the line .lI-H, Fig. 1; Fig. 3 an enlarged view of a portion of the main conduit and the upper por tion of a branch conduit; Fig. 4 a sectional view taken on. the line lV-IV, Fig. 3;.

and Fig. 5 a sectional view taken on the line VV, Fig. 4:.

Referring to the drawings, the main conduit ,1 tor carrying the mixture of coal dust and air is indicated as extending above a plurality of furnaces 2 which may be of any suitable construction and for any desired purpose, as for example, the heating of steel or other metals. As is usual in in stallations for burning coal dust, the main two burners 3, which also may be of any suitable type or construction, Extending ."fromthe main conduit 1 to each burner 3 there is an unobstructed conduit 4.

At the inlet end of each branch conduit I provide means whereby variable amounts of coal dust may be abstracted from the main conduit without substantially varying the amount of air so abstracted, or inother words, means whereby variable relative quantities of coaldust and air may be so abstracted. While various means may be usedto such end, I preferablyprovide a funnel-like orifice m ember 5 having an inletvopening 14., preferably of unvarying size, which member may be so "turned, or otherwise adjusted that the general plane ofits inlet opening may lie at various angles to the line of flow through the main conduit. v

Any suitable means may be provided for turning the orifice member 5. lnthe illustrative embodiment of my invention a pinion 6 is keyed to th'emember 5, and, meshmg wlth such p1n1on, there is a second pmion 11 keyed to a rod 12 extending downwardly to within easy reach of a workman in. front ofa furnace 2. The orifice memher is rotatably mounted in a-saddle 15 secured to the main conduit 1 by yolres 16.

.The lower end of the saddle is provided with a flange 17 to which there is attached, as by means of bolts 18, a flange 190i a valve casing 20, a suitable spacer 8 being interposedbetweenthe flanges 17 and 19 got such "thickness as to permit rotation of .stract'themaximum amount or proportion of coal dust,.the member 5 is turned to the position indicated in the drawing, the orifice l4 fully facing the line of flow, indicated by .the arrow 22, through the main conduit.

hen it is desired to diminish the amount ofcoal dust abstracted,.the orifice member is turned'eitlierto the right or to the left an amount depending upon the diminished supply. desired. It will be. understood that, when the orifice is set at an angle to the line of flow, a less proportion of coal dust will be received than when the orifice fully faces the line of flow, assuming, of course,

i that at the point of abstraction the relative mixture ofcoal .du st an d airjiremains the same. .Generally speaking, the ratio between thelalnount of coal dust abstracted by the orifice when fully facing theline of flow and when placed; at an angle to such line of flow is substantially the same as the ratiobetween the projections of the orifice on planes at right angles to the line of flow.

Because of the pressure under which the air flows, that 1s-to say the static pressure as distinguished- :trom thevelocity pressure, the

amount of air abstracted by the orificewill, within the practical rangeof adjustment of the orifice be substantially the same when the orifice is placed at an angle to, as when fully facing the l-ineoi flow; Accordingly,

by adjusting the position of the orifice, the relative quantities of air and coal dust abstracted may be varied to meet requirements,

and at the same time a strong flow oi the mixture through each unobstructed branch conduit may be maintamed.

For two reasons the relative quantities of coal dust and air carried by the, main coni duit varies with the distance of the main conduit-from the point of initial mixture. In thefirst place a certain amount of the coal dust gradually settles to, and toa large extentrema-insupon, the bottom of the conduit. Such dust is periodically blown or otherwise remo'vedgfrom theqmain conduit.

Secondly, the withdrawal of portions of the mixture through the branch conduit varies the relative proportion of air and coal dust, the proportion of coal dust usually being diminished. By providing means such as shown herein, or its equivalent, for varying the relative quantities of coal dust and air abstracted from the main conduit, the character of the flame supported by the mixture taken from any point along the mam conduit may, independently of a supplemental blast, be controlled according to requirements. In other words by varying the relative quantities of coal dust and air abstracted, either a smoky carbonizing, or a white oxidizing flame may be had regardless of the variation of the mixture in the main conduit.

According to the provisions of the patent statutes, I have described the principle and operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof. However,- I desire to have it understood that. within the scope of the appended claims. my

invention may be practised by other forms of apparatus than that shown and, descriluad.

I claim as my invention:

1. The combination with a main conduit for carrying a flowing stream oi combustion-supporting gas having solid combustible particles suspended therein, a burner. and a branch conduit extending from said main conduit to said burner, of an orifice member for abstracting from the main conduit a portion of said stream oi and particles and delivering said portion to said branch conduit. and means For rendering said orifice member effective to vary the relative quantities or said gas and particles abstracted. from the main conduit through the branch conduit.

2. The combination oi a main conduit for carrying the flowing stream of combustionsupporting gas having solid particles suspended therein. a burner, a; branch conduit extending rom said main conduit to said burner, and means at the inlet end of said branch conduit for abstracting from the main conduit variable relative quantities of said gas and particles.

3. The combination with a main conduit for carrying a flowing stream o combustion-supporting gas having solid particles suspended therein, a burner. and a branch conduit extending from said main conduit to said burnerof an orifice member in said main conduit and communicating with said branch conduit, and means for adiusting the general plane of the orifice of? said member with respect to the longitudinal axis of said main conduit wherebv variable relative fluantities of said gas and particles may be 4. The combination of a main conduit for carrying a flowing stream of combustionsupporting gas having solid particles suspended therein, a burner, an unobstructed branch conduit extending from said main conduit to said burner, and means at the inlet end of said branch conduit for abstracting from the main conduit variable relative proportions 01. said gas and particles.

5. The combination with a main conduit for carrying a flowing stream of combustion supporting gas having solid particles suspended therein, a burner, and a branch conduit extending from said main conduit to 15 with respect to the longitudinal axis of said 20 main conduit.

In testimony whereof I have hereunto set my hand.

WILBER E. HARVEY.

Witnesses:

Amen A. TRILL, PAUL N. CRrroHLow.

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