US2668048A - Foundry cupola - Google Patents

Description

1954 R. A. M. RONCERAY 2,668,048

FOUNDRY CUPOLA Filed Oct. 25, 1950 2 Sheets-Sheet l "in /v Ton ROBERTANDRE MARCH. Milli/MY Mw M ATTORNEYS 1954 R. A. M. RONCERAY 2,663,048

FOUNDRY CUPOLA Filed Oct. 25, 1950 2 Sheets-Sheet 2 INVENTOR ROBERT ANDRE mm RONCIRAY ATTORNEYS Patented Feb. 2, 1954 UNITED STATES PATENT OF F ICE Claims priority, applicationiFrance September 25, 1950 2 Claims. 1

Inthe courseof a melting operation in a cupola,

the lining: of the latter melts and its meltedparticles dripdown, along the cupola walls, until they reach the tuyre level where, by being air-cooled, they are solidified, giving rise to depositsmorea or less obstructing the tuyeres.

Most .cupolas have hitherto been constructed withthei-r tuyeres located in the same plane as the air box and arranged tooperate continuously, all-at the same time. On account of this construction, the tu-yeres are always partly obstructed, the air supply being subject to'variations-in the course of one and the same melting operation, whereby serious disturbances in the melting process are caused, resulting deficient melted products, irregularmelting'rate per'hour and variations of the pouring temperature.

On -the other hand, since the tuyeres are located in the same plane as the air box, theair pressure is not equal in all of them and is, in fact, higher in the tuyres lying in proximity to the airadmitting duct than the tuyres diametrally opposedto these ducts. Every tuyere, therefore, discharges a difierent amount of air, so that in, the cupola there occur regions in which the melting is not being carried out under desirable conditions.

There have been constructed cupolas provided with twosets of tuyeres arranged to operate alternately. In this case, the tuyres not in use are brought to so'high a temperature as to cause the depositson the tuyeres to melt away. But as the permutation of the setsof tuyres is controlled by hand and isoften left to'the decision of the furnaceman, satisfactory operation is not always absolutely ensured, thisshortcoming being aggravated by the inequality of the air pressure the tuyres.

There have further been constructed cupolas inwhich the air-box is located ata level higher than that ofthetuyeres and is'rconnected to the latter by vertical ducts. The distribution of air is better in these cupolas, but important losses of head take place in the connecting ducts.

The present invention has for its object to provide improvements in the foundry cupolas, which permit of obtaining the automatic removal of tuyere deposits, the equality of air pressure in the tuyeres, with reduced losses of head, a smaller wear of the cupola facing, and a heating of the air employed.

According to a first improvement, the cupola is provided with two independent sets of tuyres, and includes self-acting means whereby each set of tuyres may be set in action alternately.

The cleaning of the tuyres is then eiiected' regularly and entirely automatically. The air supply is uniform andhence the quality of melted products is regular.

The air supply of each group of tuyres' can be timed by the head melter and the crews therefor do not have to intervene whereby their fatigue is minimized and the operation of the cupola is even and regular at all times.

Preferably, the various tuyeres are converging According to a further improvement, which.

may be used jointly with the first one or independently, the air box is located at a level different fromthat of the tuyeres and is connected to the latter by a subdivided jacket surrounding the cupola. Inthis way, the air pressureis practically equal in all of the tuyeres and the losses of head are rendered low by the large dimensions given to. the connecting ducts. On the other hand,.the air that circulates within the jacket, throughout the height of the melting region, is warmed up by cooling this region as well as the lining of the latter. Wear of this lining is thereby substantially reduced, for the temperature of the same is about equal to its melting point,.when the cupola is in operation.

An example of execution of the improved foundry cupola, designed according to the present invention, will now be described with reference to the accompanying more or less diagrammatic drawings, it being understood that the outstanding features apparent from both the drawings and the followingdescription form part of thi'sinvention.

In the drawings:

Fig. 1 is a vertical showing of the cupola, half in elevation and half in section;

Fig. 2 is a cross-section through the line II-II of Fig. 1;

Fig. 3 is a cross-section through the line IIIl1I of Fig. 1; and

Fig. 4 is a detail view showing the distribution shutter.

Referring to the drawings, it will be seen that the cupola l, whose lining is denoted by reference 2, is provided with an air box 3 connected to the air supply duct 4 and divided into two portions by a transversal partition 5. A shutter 6,

provided with an aperture 6a, is placed across the duct 4 and adapted, when being displaced, to set this duct in communication with one or the other portions of the box 3. The shutter 6 is connected to a, piston 1 slidable in a double-acting cylinder 8. Compressed air may be sent into one or the other cylinder end throu h the intermediary of a valve 9 actuated by an adjustable clockwork I0.

A jacket H, made of welded sheet metal, surrounds the cupola below the air box 3 and is provided with partitions such as I2 adapted to define compartments such as 13. One of every two of these compartments communicates with the upper portion of th -air box through apertures such as 14 formed in the partition 5, while the other compartments communicate with the lower portion of this box through apertures such as l5 formed in the bottom of said box.

At their lower ends the compartments [3 communicate with radially extending tuyeres such as l6 equally spaced circumferentially of the cupola and each of which tuyres has a converging longitudinal cross section with the small end thereof opening on the inner wall of said cupola. Inspection doors such as I! are positioned in front of the tuyeres IS.

The clockwork I0 is for setting in operation alternately the tuyeres IS in communication with the upper portion of the air box 3 and the tuyeres in communication with the lower portion of this box. The tuyeres which are thus caused to be out of action are brought to high temperature and their deposits melt away. The air flowing into the jacket H is heated and its pressure is practically equal in all of the tuyeres in action.

The outlet [8 of the cupola opens into a decanting vat IS. The iron slag which is lighter than iron rises to the surface and flows therefrom through an upper passage 20, while the iron collects in the bottom of the vat l9 and is withdrawn through a lower passage 2!.

The melted products obtained with such a cupola are of better quality than those obtained with the cupolas hitherto known, since the pouring temperature of the former is more regular. The output of these Products varies within narrow limits. The melter does not have to busy himself about the cleanness of the tuyeres, and

his inspection work is reduced. The air blast is heated, and the condition of the lining is improved, especially where this is most exposed.

What I claim is:

1. An improvement in foundry cupolas comprising a cupola, an airbox surrounding the middle portion of said cupola, a partition extending transversely of and within said airbox and separating said box into two sections positioned one above the other, an air inlet duct connected to said airbox and in communication with both of said sections, a shutter slidably mounted between said duct and said airbox and having an opening capable of placing said duct in communication with one of said airbox sections at a time according to the position of said shutter, a pneumatic jack connected to said shutter for operatin the same, a clockwork mechanism operably connected to said jack for automatically operating same, a plurality of tuyeres provided through said cupola all on the same horizontal plane below said air box, a plurality of vertical conduits connecting alternate tuyres to one of said airbox sections, and a second plurality of vertical conduit connecting the remaining tuyres to the other of said airbox sections.

2. An improvement in foundry cupolas comprising a cupola, an airbox surrounding an upper portion of said cupola, a partition extending transversely of and within said airbox and separating said airbox into two sections positioned one above the other, an air inlet duct connected to said airbox and in communication with both of said sections, a shutter slidably mounted between said duct and said airbox and having an opening for placing said duct in communication with one of said airbox sections at a time according to the position of said shutter, a pneumatic jack connected to said shutter for operating the same, a clockwork mechanism operabl connected to said jack for automatically operating same, a plurality of tuyeres provided through said cupola all on the same horizontal plane below said airbox, a jacket enclosing the portion of said cupola extending from said airbox to and below said tuyeres, said airbox having an annular opening provided in the bottom thereof, said transverse partition having an annular series of openings provided therethrough, a plurality of partitions extending vertically of and radially across said jacket and through said airbox opening and the lower section of said airbox to said transverse partition providing a plurality of conduits with alternate conduits thereof, connecting alternate tuyeres with said transverse partition series of openings to said upper section and the remaining conduits connecting the balance of said tuyeres with the lower section of said airbox. i

ROBERT ANDRE MARCEL RONCERAY. I

References Cited in the file of this patent Reece May 31, 1949

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