US703768A - Furnace. - Google Patents

Description

, Patented July I, I902. P. CORRIGAN.

F U B N A C E (Application filed Mar. 30, 1901.) 4

(No Model.)

WITNESSES UNITED STATES TENT OFFICE.

PHILIP CORRIGAN, OF W'AKEFIELD, NET/V YORK.

FURNACE.

SPECIFICATION refinin part of Letters Patent No. 703,768, dated July 1, 1902.

Ap IiOationJfiIedMarch 30, 1901. Serial No. 53,722. (No model.)

T0 aZZ whom/it may concern: 7

Be it known that LPHI IP CORRIGAN, a citizen of the United States, residing in Wakefield, in the borough of the Bronx, in the city and State of'N ewrYork, have invented'a certain new and useful Improvement in Metallurgical Furnaces,of which the following is a specification.

I have in my experiments applied the improvement to furnaces of moderate size burning gas as a fuel andused'for melting and refining precious'metals and will-describe it as thus applied. It presents the pipes conspicuously in sight under all conditions,*allowing constant inspection and easy acoess*for adjustment or repairs when necessary, and especially provides for the easy removal and exchange of the burners through which the mixture of .air and gas is projected into the furnace. I

I designate as burners the pipes usually arranged tangentially in the walls of the furnace. They correspond generally to the parts sometimes designated twyersin large furnaces for reducing and melting metals, the

inner end of each coinciding approximately with the inner face of the furnace, the main body lying within the wall and the outer end being adapted for joining to a pipe which supplies air and gas.

My burners may be in whole or in part'of fire-brick, plumbag'omr other refractory material; but the outer portion of each, being sufficiently distant from the heated locality, may be ordinary cast-iron.

My invention allows for so easy exchange that I have in my experiments made each entire burner a single casting of ordinary soft iron.

The following is a description of whatjI consider the the best means of carrying out the invention.

The accompanying drawings form a part of this specification.

Figure 1 is a side elevation. Fig. 2 is a horizontal section on the line 2 2 in Fig. l with portions shown in plan. The remaining figures show portions on a larger scale. Fig. 3 is a plan view, partly in horizontal section, showing one of my burners and its connection to the other pipes. Fig. 3 is an end view of the outer end, showing the mark by which the position of the delivery-slot of the burner is clearly visible from the outside. across-section on the line 4 4 in Fig. 3. Fig. 5 is an end view of the delivery-nozzle of the burner. 'Fig. 6 is a horizontal section of the delivery end and the adjacent portion of the furnace on'the same scale asin Fig. 3,showing a modificatioma beveled end to the burner; and Fig: 6 shows the preferred plan for marking the outer end when such nozzle is used.

Similar letters of reference indicate corresponding parts in all the figures where they appear.

A is the base or bottom, A the fire-brick lining, andA the exterior brick or backing. These latter may usually be of ordinary brick; but the Whole may, if desired, be fire-brick in' as many or fewpieces as may be preferred.

0 is a rectangular outercasin'g of cast-iron or other suitable material holding the Whole reliably together. Two smooth tangential passages do are provided on opposite sides of the'furnace,'and in'these my'burners are inserted by being'Ithrust in ward from the out 'D' D. designate theinner end sof my burners, each partially closed, but having a liberal slot at extendingdiametrically across.

'Ddesignates the main bodies tapered, as shown.

D is a short screw-threaded portion matching the screw-threads in either't" 01-5 and D? a cylindrical open-workextension;

D is the closed outer porti'on, carrying a smaller continuation having its end D squared. A cross-mark d is cut'on' the outer face of the extreme end, which'mark lies in the same plane as the slot cl at the inner end, so that'the mark serves as anindex to show how the'slot is turned. ThG'b'illIl'GIl should always be adjusted with the slotd extending up and down, so that a flame having more height than thickness'shall result from the combustion of the gas as it flows from each slot into the furnace and spirals around therein. The inner ends of the burners presented to the interior of the furnace are the parts which are liable to be destroyed by the heat.

The tapering bodies D of the burners are allowed to fit' easily and may be left a little Fig. 4 is' loose, or the slight space around each maybe .terial.

packed with fire-clay or other refractory ma- I preferto leave the joint open.

13 is the pipe, bringing air under pressure which has been forced by a blower, (not shown,') and O is a stop-cock controlling; the How. B is a tapering nozzle, through which it is ejected with force into a pipe B where it mingles with combustible gas received under a gentle pressure through a pipe E, controlled by a cock F, by the aid of a pump or blower. (Not shown.) The pipe B extends across the front and thence rearward. At points therein on opposite sides of the furnace are two chambers I I, slightly larger than the pipe, each of which serves the important function of receiving a burner D, extending through it transversely and allowing such burner to be easily inserted, adjusted, and

removed. Each chamber I has .a screwthreaded hole 1; in its outer side and a similar hole i in its inner side. Each chamber I and its holes 6 i must be setin line with one of the tangentially-arranged holes a in the brick-work, which receive the inner end and main body of each burner.

Three or a larger number of similar burners D must be provided, so as to serve interchangeably. One is introduced in each chamber'I, turning each properly to traverse the outer screw-threaded hole i, and again after afurther thrust to properly enter and engage in the inner hole 2' After it is home a detachable stuffing-box M, screw-threaded on its exterior, is slipped over the contracted end D D and engaged in the hole t" and screwed in. A ring'of any convenient soft packing H is applied inits screw-threaded interior m, and a ring or gland G, screwthreaded on its exterior, is applied and turned to properly compress it. I have used asbestos as packing; but as there is little heat any packing whichwil'l make a fairly gas-tight joint will serve. The inner end D of the burner should be about flush with the interior of the furnace. If it extends too much it is less able to Withstand the heat, and it should not be too much drawn back. Unscrewing the stuffing-box M liberates the burner, so that the latter can be turned as many half-turns as required in either direction to adjust it farther in or out, taking care to always leave it with the mark d extending up and down, and alwaysretightening the stuffingbox after such adjustment. The part M serves a double function-one as a stuffing-box and another as a jam-nut, which being screwed in with force insures the absolute fixity of the burner until it is again unscrewed. v

The complete removal of the burner and the supplying of another may be effected in a very short time even when the furnace is at full heat. To efiect this, I shut the cooks O and F, thus stopping the supply of air and gas, apply a wrench to the outer end of the jam-nut stuffing-box M, (flat places being formed there to allow this without injuring thethreads.) and remove that part. Then apply a proper wrench to the squared end D and turn the burner, drawing it gradually back. When the screw-threaded portion D is clear of the screw-threads in the inner orifice '6 the burner may be moved directly outward until the screw-threads on D contact with the screw-threads in the outer orifice i,

when the burner must be again turned until these threads are passed. Then it may be drawn out directly and its hot inner end examined. If exchange is expedient, a spare burner is introduced in its place, and a reversal of themovements and a proper adj ustment' of the new burner and of thesame stuifing-box jam-nut M, its packing. H, and ring G, or of a new one of each, makes all ready, and the gas and air. being again turned on the furnace is again serving as before.

It is not essential that the air which is allowed to mix with the gas at the reduced nozzle 13 shall be sufficient to attain complete combustion. The force with which the mixture of air and gas is projected into the furnace draws in additional air through the small space around my tapering burner, and the air thus received at ordinary pressure in addition to that received at the earlier stage at a pressure above atmosphere together should be a'little more than sufficient to effect complete combustion.

The hole a being tapered and the burner D, which fits loosely therein, being also tapered, it follows that the adjustment of the pipe D inward and outward by the means described will have the effect to modify the quantity of air which isdrawn in at atmospheric pressure around the burner, screwing the burner D in contracting the annular space and reducing the quantity of air admitted through it, and

drawing out the burner D, enlarging such space, and increasing the quantity of air thus admitted.

The general form of my furnace may correspond to one which has beenlong approved, having sliding doors K, arranged to be moved laterally on suitable ways to cover and uncover the furnace conveniently when desired; The flame from my burners travels spirally around in the interior of the furnace in the approximately annular space between the crucible W and the inner wall A of the furnace and escapes through the flue a into the chimney. (Not shown.)

My furnace is accessible for inspection or repairs in the ordinary manner. The provisions for controlling the air and gas may be adjusted with great nicety and changed without difficulty, as conditions may require,

whilethe furnace is working.

The most likely points to fail in afurnace of this general character are the inner ends of the burners. My burner may be simply and cheaply constructed as asingle casting, the only parts requiring to be finished being the screw-threads on D and the stuffing-box.

IIO

A single stuffing-box may serve with a number of successive burners.

Modifications may be made without departing from the principle or sacrificing the advantages of the invention. lhe form of the casing O, constituting the exterior of the furnace, may be cylindrical or of various other forms instead of rectangular. In such case or in any case the pipe 13 may be curved instead of having straight portions, as shown. There may be three or four or only one instead of the two burners shown, providing a corresponding number of the other parts.

The inner end of the burner may, if pre ferred, be beveled, as shown in Fig. 6. This will allow it to coincide more perfectly with the inner surface of the fire-brick lining A of the furnace; but it interferes with the nicety of adjustment, forbidding its being left half revolved. When such form is adopted, a mark not extending across, but on one side alone, as the prick-punch mark 01 may be employed, by which to insure that it is correctly arranged.

It is not essential that the portion D of the burner be cylindricahwithjbars extending longitudinally and all the spaces between open, as shown. It is only essential that it be not too large to allow the burner to be introduced and withdrawn by longitudinal movements and that it have liberal apertures-whatis commonly termed open-workthere being metal connecting the outer and inner portions of the burner, but with sufficient spaces to allow the mixture of gas and air to freely traverse inward from the chamber I, and thence flow without obstruction to the nozzle and be discharged into the furnace.

I claim as my invention 1. In a metallurgical apparatus, a furnace A having a tangential passage a leading from the outside of the furnace-wall to the interior space of the furnace and a supply-pipe B ing the threads D the portion ,D of the burner being open-work so as to constitute a strong extension of the burner across the chamber I, but so liberally apertured as to freely admit the gas and air, such apparatus being adapted toallow the burner to be ad- 3' usted outward and inward and to be removed and replaced when required without disturbing the other parts, all substantially as herein specified.

In a metallurgical apparatus having a furnace-lining A with a passage or leading from the outside to the inside of the furnacewall, and a supply-pipe B arranged to bring gases under pressure, a chamber I in said supply-pipe having the internally-screw-threaded part 1" and also having the internally-screwthreaded part i for holding the burner and a burner D extending longitudinally ofsuch passage and having the screw-threaded part D thereon, in combination with each other and with the screw threaded ring M m matched in the screw-threaded orifice t" on the outer side of said chamber, adapted to serve the double function of a stuffing-box and a jam-nut, all substantially as herein specified.

In testimony that I claim the invention above set forth I'affix my signature in presence of two witnesses.

PHILIP CORRIGAN.

Witnesses:

J. B. CLAU'IIOE, M. F. BOYLE.

Images