US2549806A - Electric fuel igniter - Google Patents

Description

April 24, 1951 w. D. HALL 2,549,806

ELECTRIC FUEL IGNITER Filed April l, `1947 /AT/s A? UM/fam l). Haz/H /3 /4 14 Horneys .ned generically in the clairns.

Patented Apr. 24, 1951 Stdte ELECTRIC FUEL IGNITER William D. Hall, Elkins, W. Va.

Application April l,

5 Claims.

Serial No. 738,600

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 i). G. 757) The invention described herein may be .manufactured and used by or ior the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to igniting devices and more particularly to igniters for coal furnaces.

The main object of this invention is to provide an igniting device that may be inserted in a bed of coal to effectively ignite the same without use or kindling wood. Other objects and advantages of the invention will appear as this description proceeds.

The invention is of broad scope and will be de- The speciiic structure involved includes `a heating coil suitably protected from damage by a ceramic element. After the coal is heated by the heating coil the flame may be built up by either or both of two additional features, namely (c) a blower for supplying air to the coal, and (b) by passing a heavy current through the coal itself. Further details will appear as this description proceeds.

In the drawings:

Figure l is a sectional view of the coal furnace igniter.

Figure 2 is a sectional view of the igniting head taken along line 22 oi Figure l.

Figure 3 illustrates the electrical circuit employed in the device.

Referring to Figure a cera-mic supporting base lil of a suitable insulating compound has embedded therein and very close to its outer surface a helical coil il of the highest quality heating wire. This wire may be wound within the ceramic base in any suitable manner but preferably should be wound so as to give a maximum temperature at the surface of the base IG without overheating the wire. Pipe I2 supports the lil. Electrodes I3 and it in the form of rings are mounted at opposite ends of base iii and are respectively connected in the circuit as shown in Figure 3. The pipe I2 is insulated from contact with any metal parts of any furnace to which it contacts by insulation i5. The pipe I2 carries insulating supporting member it which in turn supports conical hood il'. A blower I8 is driven by motor M and propels air down pipe I2. This air is reflected by cone il back into the reeon of the :Elaine initiated by the igniter. Two switches iii and i@ are respectively in series with the blower motor M and the heater wire i i; and power at 115 volts, for example, is supplied by domestic lighting 2i. The iiow oi curn rent to rings if! and il may be controlled by switch is or by an independent switch if desired;

Eil

y2 and switch I9 may be an off-on switch or may be a step switch which cuts out a resistance in steps to gradually increase the voltage oi the circuit.

In order to ignite a bed of Vsoit coa-, the conical element l'I is rammed in the bed. It protects the parts I to Ill during this operation, The switch 2i) is then closed energizing heater wire I I which in turn heats the soft coal. This heat will not only cause ignition of the coal but will drive out of it a thick liquid.

At this point switch IS may be closed (or in the alternative it can remain closed from the beginning) causing a heavy current to flow from electro-de I3 through the coal to electrode I4 thereby generating a very high degree of heat. The blower i8 will propel air down pipe .l2 which air is reected back by cone lI in to the bed of ignited coals around part Iii. Switch 2d may now be turned off, The air from the blower will thereupon build up the naine to a large extent.

It is of course possible to oinit the electrodes i3 and I4 and allow the heater wire II to ignite the coal alone but the process of igniting the coal is somewhat slower under these circumstances and furthermore the heater wire does not last as long. With the electrodes i3 and I4 it is not necessary that the heater wire II actually heat the coal to igniting temperature. Heater wire I I may heat the coal just enough to start conduction through the coal itself. Therefore the heater wire l l may run cooler than it would necessarily run without the electrodes I3 and I4.

When cold, soit coal is not suiiiciently conducting to be ignited by merely passing current therethrough from ordinary domestic power sources. However, if the coal is preheated by heater wire l I, it may be ignited from domestic lighting circuits by passing current directly through the coal.

I claim to have invented:

l. An igniter for soft coal comprising an elongated pipe, a blower at the rst end of the pipe for forcing air through the pipe, an electric motor for driving the blower, a circuit for energizing the motor, a Switch in said circuit, a ceramic base carried by said pipe at the second end therean igniting wire embedded in base for raising the latter to igniting temperature, said ceramic base covering said igniting wire to insulate the wire from electrical contact with the coal, a pair oi spaced electrodes mounted on said base, wires connecting said electrodes respectively across opposite sides of said circuit, and a conical hood of larger diameter than the pipe and mounted on the second end of said pipe for deilecting the air therefrom back to the second end of the pipe and across said base.

2. An igniter for solid fuel comprising an element of insulating material, a handle for the element enabling the latter to be rammed into a bed of coal, a heating wire covered by said element and insulated mechanically and electrically from contact With the fuel for heating the element, spaced electrodes adjacent the element and arranged to contact the heated fuel, and means for applying sufficient electrical potential across said electrodes to cause sufficient current to pass through the heated fuel to ignite the same.

3. An igniter for a bed of soft coal comprising a block adapted to be rammed into a bed of coal and having a continuous ceramic surface, a heating wire embedded in the block for heating said surface to thus render coal adjacent the surface conducting, spaced electrodes adjacent the surface for passing current through the coal adjacent said surface, means for supplying current to the electrodes through a path independent of the heating wire, said means including means for supplying sufcient current to said electrodes for a suicient time duration to ignite coal, a blower for blowing air into the bed of coal after the latter has been ignited, said blower having an air output duct, a hollow handle supporting said block at one end of the handle, and means connecting the blower to the other end of the handle and said duct to feed the hollow handle at that end of the handle that connects to the blower.

4. An igniter for soft coal as defined in claim 2 in which said insulating material is the only element that separates the wire from contact with the coal.

5. An igniter for soft coal as defined in claim 2 designed to operate from an outlet of domestic electric power in which the wire has such high resistivity that when it is connected across said outlet it is heated to a temperature below the ignition point of the coal, said electrodes being so closely spaced that when connected across said outlet they will pass sufficient current directly through the coal to ignite it after the coal has been heated by said Wire.

WILLIAM D. HALL.

REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 16,149 Southgate Aug. 25, 1925 1,587,197 Southgate June 1, 1926 1,977,151 Schottky Oct. 16, 1934 2,192.732 Johnson Mar. 5, 1940 2,210,720 Johnson et al Aug. 6, 1940 2,234,004 Lamm Mar. 4, 1941 2,291,007 Titcomb July 28, 1942 2,438,823 Resek et al Mar. 30, 1948 2,492,705 Mason Dec. 27, 1949 FOREIGN PATENTS Number Country Date 105,870 Switzerland July 16, 1924 334,523 Germany Mar. 1, 1922 336,633 Germany Mar. l, 1922 720,416 Germany May 5, 1942

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