US2368802A - Radiant mantle - Google Patents

Description

Feb. 6, 1945. w. G. CARTTER ET AL RADIANT MANTLE Original Filed Jan. 29, 1940 'W/ZL/AM 6. CARTTEE freq/W65. Wboo INVENTORS Arroen/s Patented Feb. 6, 1945 RADIANT MANTLE 'William G.

Cartter and Frank E. Wood,

Monrovia, Calif.

Original application January 29,, imaseriaim.

316,116. Divided and this application. October 20, 1941, Serial No. 415,743

4 Claims. 01. 158-113) 'I'hisinvention relates generally to the gas heating art and particularly to a radiant mantle for incorporation in a gas heater. By gas heater .we intend to include: any type of heater in which the combustion of a fluid generates the heat.

This application is a division of our comnding application, Serial No. 316,116, filed January-29, 1940, for Radiant mantle, Patent No. 2,280,061. In the present divisional application we claim a different species pursuant to requirement for election of species in the parent application.

At the present time space heaters are being provided which utilize. gas as a fuel and which incorporate a memberinterposed between the gas and the space to be heated wherebythe interposed member is heated to a point of incandescence.

It is the principal object of the present invention to provide a heater whichmay be used' in connection with stovesor the like for cooking purposes but which is more especially adapted for heating the air in a. given space, suchfasa room, and which structure is small and compact in design and embodies the use of a burner and a mantle element made of. metal which in use is heated to a point of incandescence so that heat is radiated.

It is a further object of our invention to provide a foraminous mantle of the character described in which he'atedgases may. readily pass through and upwardly away from themantlein aid of combustion in the burner below as well ,as providing for circulating heat in addition to the radiant heat emanatingfrom the mantle.

It is a, further object of the invention to provide means whereby the burner whichis below the mantle may be ignited before a sufficient amount of gas accumulates between the burner and mantle to cause danger of an explosion.

It is another object of the inventionto provide a mantle fabricated from metal which is cheap in construction cost and may be readily made to conform to any desired configuration, and will retain its original shape when subjected to intense heat.

The present invention is intended especially for use with a burner enclosed withina housing to furnish a-ccmbustion chamberv as disclosed in our Patent No. 2,263,432, the mantle being located at the upper end of the housing, the burner and the mantle being formed with cooperating means whereby the flame from thebu'rner may be directly ignited through the mantle for instantaneous combustion and. without impairing the usefulness of the mantle as an incandescent radiant heating element. The. mantle has somewhat the appearance of an electric resistance grid althoughv it isheated by the use of gaseous fuel.

In the drawing:

Figure 1 is a vertical section through a burner assembly incorporating our mantle.

Figure 2 isa schematic plan view of the burner assemblyillustratingthe spiral arrangement of the coiled wire. used in the mantle. Figure 3 is anenlarged fragmentaryplan view of the mantle shown in Figures 1 and 2;

Figure 4 is an enlarged fragmentary vertical section.of the mantlealong section line ,4-4 of Figure 3. 1

Referring more particularly to the drawing, Ill indicates a burner assembly connectedby a tube H with a suitable source of fuel supply and including-a valve 12 and a burner 13. Above the burner is an ignition tube M supported by arms l and in line with an orifice, not shown, in the upper face of the portion 16 of the burner. The arms position the. inner end of. the ignition tube l4 above the end face of the burner also providing aspace H. The upper end, of the. tube l4 terminates at a. desired position as will be hereinafter set forth. When the valve is opened a mixture of gas and air ascendsv from the. burner 13 into the tube l4 and is there ignited. The flame thentravelsback down thetube. l4 and ignites the gaseous mixture which. is issuing from the burner.

Supported upon uprights 2i)v of the burner structurelfl is a housing or drum 2|. I The drum 2-l: ismounted concentrically with the axis of the burner and; the ignition tube. The upper end of thedrurn 21 is open and in the preferred form of the invention here shown defines a circular space within whichv a radiant mantle 30 is positioned. Thismantle-is of special design. and novelty.

By reference. to Figures 1, 2 and'3 of the drawing it "will beseen that the mantle comprises a. continuous wire coiled in the form of a helix as indicated at 3f, the coil being arranged spirally in a single plane shown sechematically in Figure '2.

A wire '32 is passed longitudinally through the coil preferably before it is formed into the spiral, and also is preferably spotwelded at spaced points to aid inmaintaining the coil in position. An illustration of the spot welding is indicated at 33.

Additional support may be provided by a radial spider 34, the outer ends of which are welded or otherwise attached to-a circumferential confining band 35. This spider may bemaxie with 'a' central collar 36 providing an opening through which to light the burner as well as a barri'er against which theinner convolution of the spiral rests.

The central-collar is not a necessary element ofthe invention as the coil may be welded to the inner ends of the spider arms.

We prefer tolocate the-wire 32' along the lower inside sur-face of the coil, and having installed the wire and secured it at various points by spot welding, the spiral may then be formed; after this the arms of the spider are inserted in a radial direction and secured to the collar 36 (if used) at their innerends and to' the confining band 35 at their outer ends. The confining band thus retain the form of the mantle. The spacing of the adjacent convolutions of the coil is pri-' marily a matter of design within certain limits, it being desirable that the'convolutions be close enough together to provide-in effect a'continu'ous perforate surface. I

In speaking of a wire coil We contemplate either a circular, a square, or rectangular type of wire coil. 3

By the arrangement described it will be seen that the convolutions of the radiant element will be securely assembled and will maintain their aligned position within a flat plane at the upper end of the drum 2|. Ordinarily the mantle will be welded into the drum at the Figure '1.

The wires forming the coil 3| and the wire 32 may be made of any suitable metal or alloy such for example as chrome steel.

At the vortex of the spiral forming the mantle position shown in 7 of circular if desired without changing the elements of which itis comprised,- or -it may even be laid out in a rectangular pattern.

While the form illustrated is planular, the

sarne elements are adequate to make the mantle conical, either natural or inverted, and such i modification is within the scope of our invention.

is a central opening 31 which as previously described may be formed by the collar 36- or merely defined by the inner convolutions of the wire coil. This opening is disposed directly above the upper. open end of the ignition tube l and is for thepurpose of facilitating the lighting of the gas issuing from the upper end of the tube; It

the mantle is designed so that the pitch of the coiled wire'is long and there is considerable space between successive turns it is feasible to eliminate the central opening 37 and light the gas as it issues up throughthemantle.

The mantle-is placed above the burner a sufiicient distance so that the mantle is above the normal upper limit of the flame and so the flame will heat the mantle to incandescence but .will not pass through the mantle. wire coil convolutions should be sufiicient for the heat. at the upper limits of the burner flame to readily. penetrate. Any combustion which may occur at this point willinot be visible to the eye and when the mantle has become properly heated the. incandescent glow will dominate the burner flame and the latter will not be normally visible.

7 ,In the operation of the invention the burner structure is assembled as shown in the drawing and. isconnected to a suitable source of fuel. This fuel is preferably a gaseous fuel which when delivered to the'burner will produce a combustible gas. Igniting means is placed at a point above thesurface of the mantle and will temporarily ignite gas passing therethrough after which the flame will ignite the gas in the end of the tube l4 and then ignite the burner. When the burner is in full operation the combustion'takes place within the drum 2| and the mantle will be heated to the point of incandescence, I It will thus be seen that the structure described provides simple and effective meansfor heating air by radiation without sacrificing circulation and by theuse of a gaseous fuel and'that further,

The spacing of the.

Our concept is a radiantmantle for gas heaters in which the mantle is placed in the burner assembly between the burner itself and the normal heat exit preferably above the normal upper limit of flame from the burner. The mantle is a coiled wire suitably supported in the form of a spiral or other arrangement in which the coiled Wire occupies most of the area covered by the mantle, with the aid of a wire extending longitudinally through the coiled wire and assisted by radially arranged'spider arms, The pitch of the'convolutions in the coil must be sufiicientlygreat to provide ample space through which heated .gases may rise in aid of'combustion in the burner below as well as to prevent fusing of the metal. The supporting means must be firm enough to retain the shape of the mantle as formed Without presenting any substantial bulk to obstruct the upwardflow of the heated gases. It is desirable that the material and proportions of the coiled wire and the supporting elements be such that they heat evenly and maintain comparable incandescence.

the coil and secured to's'aid coil, and a radial support comprising thin metal bars vertically on edge extending transversely through the spirally arranged coil. Y

3. A mantle for radiantheaters comprising: a wire coil arrangedinspir'al shape, and means for holding the coil as thusarranged, said means comprising awire passing longitudinally through the coil and secured to said coil, and a radial support comprising thin metal bars vertically on edge extending transversely through the spirally arranged coil, said wire being disposed at-the intersection of thebvertical diameter of the. convolutions of the wire coil, and thesaid metal bars occupying the remainder of such vertical diameter.

4. A mantle for radiant heaters comprising: a wire coil arrangedin spiral shape, and means for holding the coil as thus arranged independently of any physical contact of the convolutions of the spiral diametrically thereof, said means comprising awire passing longitudinally through the coil and welded thereto at a plurality of locations along the'lower inside surface of the coil, and-radial bars extending transversely through the coil, said bars engaging said wire' at their

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