US2959409A - Cupola furnaces - Google Patents

Description

Nov. 8, 1960 F. w. NEvlLLE CUPOLA FURNACES Filed DBC. 19. 1957 ATTORNEY United States Patent O cUPoLA FURNACES Frederick Walter Neville, Woodford, England, assgnor to J. W. Jackman & Company Limited, Manchester, England Filed Dec. v19, 1957, Ser. No. 703,809

2 Claims. (Cl. 266-42) This invention has reference to cupola furnaces.

It is customary to arrange for the supply of air to a cupola furnace to be blown into a wind #belt or air chamber, from which it is blown into the furnace through the tuyeres connected to or opening into the wind Ibelt. At times on small furnaces a wind belt is not always used though there is an equivalent means of air supply. In whatever manner the air is supplied lto the wind belt at present it ows round the wind belt or its equivalent to supply the tuyeres and thus has a circumferential velocity, and while the axis of each tuyere is radial to the centre of the furnace, the air ow to the furnace is not radial but the air tends to pass along the side of the 'tuyere facing the incoming air. It is also the case that in all cupolas there is a tendency for slag to form at the outlet from Ithe tuyere, i.e. inside the furnace and such slag when `formed is at present removed manually.

The present invention has for its object to improve the air supply means to the tuyeres and the furnace, whereby the air shall enter the furnace substantially radially, giving thereby a more uniform distribution of air, and provide means whereby any slag which may form is more easily removed than it is at present.

Broadly, :the radial injection of air through the tuyeres ensures a combustion zone more nearly of uniform height, which is desirable for uniform melting conditions over the area of the cupola; while the removal of any slag which may form s by stopping the air flow to a particular tuyere and allowing a small quantity of hot gas to leak back into the tuyere and out to atmosphere through the slag, which is thus melted, and to elect the injection of the air and the leak of hot gases controlling valves are provided so that either operation may take place.

The invention is more particularly set forth with reference to the accompanying drawings in which Fig. 1 shows a sectional elevation of the wind belt and a control apparatus mounted in it, for one tuyere; Fig. 2 is a transverse section on line 2 2 of Fig. 1; and Fig. 3 is a fragmentary sectional elevation showing the control apparatus in a different position.

As shown in the drawing, a wind -belt 1 is provided round the furnace, the wall of which is indicated at 2. From the bottom of the wind belt, the bottom of which is above the tuyeres 3, at each tuyere position an air duct or pipe 4 rises toward the top of the wind lbelt and is of sucient height to ensure that the air passing down it from the wind belt is substantially denuded of circumferential movement. The top of this pipe 4 has a valve head S on a valve rod 6 passing downward through the pipe and into an elbow 7 connected to the tuyere 3. In this elbow is a small aperture or leak hole 8 controlled by a valve 9.

The valve rod 6 is raised and lowered -by a pivoted handle 11 which is connected lto the valve rod through pivoted linkage. 'I'he vertical section of pipe 4 is connectcd to the elbow section 7 by a flanged collar section 4a which has an eccentric extension forming a radial recess 4b. The handle 11 is pivoted in the side walls of this recess by pivot pin 11a which is fixed to the handle. Welded or otherwise secured to the pin 11a within the recess 4b is a pair of arms 10 which in effect form ICC extensions of the lever 11 with their inner or free ends straddling the valve rod 6.

These arms 10 at their free ends are pivotally connected to the valve rod 6 through a pair of links 12a which are at their upper ends pivoted .to the links 10 and at their lower ends are pivoted to the valve rod 6 by pivot 12. A reduced extension 13 of Ithe valve rod 6 carries the valve 9 in proper relation to open and close the leak hole 8 as the valve rod is lowered and raised.

As shown in Fig. 1, adjusting the handle to the raised or horizontal position moves the valve rod 6 down and closes the valve S and opens the valve 9. The lowering of the handle to the position shown in Fig. 3 raises the valve rod 6 and opens the valve 5 and closes the valve 9.

To hold the lever 11 in its two adjusted positions against accidental displacement, a Idetent plate 11b is provided shown as integral with the collar section 4a and extending radially adjacent the lever. This plate has two spring detents 11e which snap into a depression in the opposing face of the lever.

When the furnace is in operation the top valve 5 on the vertical pipe 4 is raised so that the air flows straight down round the elbow and issues radially from the tuyere 3 into the furnace. If any slag should form at the tuyere mouth inside the furnace, :the Valve 5 is closed to out off the incoming air and -the lower valve 9 is opened. As'this operation is done to one tuyere only at a time While the other or others supply the blast, it follows that there will be a leak of hot gas through the formed slag which will be melted, the gas passing back along the tuyere out to atmosphere -by way of the leak hole 8.

While the drawing shows the apparatus as applied to one tuyere only, it is to be understood that each tuyere has its own set of controlling apparatus.

The valves may be operated individually by hand or automatically in sequence under time control at any desired time interval, which may be set or varied according to conditions or observation.

I claim:

1. Mechanism for supplying air to a tuyere of a cupola `furnace or the like, said mechanism comprising an air supplying wind belt, an air duct, one end of said air duct communicating with .the interior of said wind belt and the other end of the air duct being adapted to communicate with the tuyere of a cupola furnace or the like, said air duct comprisesa straight pipe section and an elbow section, said pipe section extending a substantial distance into the interior of said wind belt whereby circumferential movement of the air passed into said air duct from the wind 4belt is virtually eliminated, an aperture in said duct constituting a leak hole, valving means adapted selectively and positively to seal said one end of the duct while opening said aperture to the atmosphere or to seal said aperture while opening said one end of the duct to the air supply in the wind belt.

2. Mechanism as claimed in claim 1 wherein said aperture is disposed in the elbow section of the air duct and said valving means comprise a valve rod extending between said aperture and said one end of the air duct, a valve head mounted at one end of said rod and adapted to seal said one end of the air duct, a second valve mounted at the other end of the rod and adapted to seal said aperture and linkage means for moving said rod axially within said air duct.

References Cited in the le of this patent UNITED `STATES PATENTS 866,825 Summers et al Sept. 24, 1907 1,667,571 Titgen Aug. 24, 1928 1,853,120 Fletcher Apr. 12, 1932

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