US2797081A

US2797081A - Carbon burner

Info

Publication number: US2797081A
Application number: US75066A
Authority: US
Inventors: Francis J Sullivan; Edward J Bair; Justin H Allen
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-02-07
Filing date: 1949-02-07
Publication date: 1957-06-25
Anticipated expiration: 1974-06-25

Description

J n 2 1957 F. J. SULLIVAN ET AL 2,797,081

CARBON BURNER Filed Feb. 7. 1949 IN VEN TORS Jus tin h. Al/en Edward J 5 BY Francis J \su/flvan CARBON BURNER Francis J. Sullivan, Detroit, Mich, Edward J. Bair, Seattle, Wash., and Justin H. Allen, Topeka, Kans., assignors, by direct and mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Application February 7, 1949, Serial No. 75,066

Claims. (Cl. 266-19) Our invention relates to combustion equipment and more particularly to an apparatus and system for the separation and recovery of uranium or other elements which produce non-volatile oxides, from carbon and the like.

In the separation of uranium isotopes by the electromagnetic process, for instance, the uranium is collected in carbon receivers or pockets, where it embeds itself in the carbon. In order to recover uranium, or other element or elements, the carbon is burned or ignited and the uranium or other element or elements in the form of an oxide or oxides in the ash residue may be extracted by the application of nitric acid to form a nitrate or nitrates of elements to be recovered. In order to carry out this 7 process, provision must be made for the separation of any uranium or other desired element from the gases of combustion. Provision must also be made for controlling the combustion temperatures and for conducting away the heat of combustion so that the retort or inclosure will not burn out or be consumed. In the prior art many diflerent types of burners for this purpose have been tried. However, most of them were complicated, employed hopper feeds, oxygen jets, and cooling jackets, but very little filtering apparatus was provided for removing entrained uranium or other desired element in the gases of combustion.

Applicants, with a knowledge of these defects in and objections to the prior art, have for an object of their invention the provision of a burner for quantitatively burning highly enriched carbon on a production scale.

Applicants have as another object of their invention the provision of a burner whose heat of combustion may be carefully regulated.

Applicants have as another object of their invention the provision of a burner having a simple and compact arrangement for absorbing and conducting away the heat of combustion so that it may not be injurious to the equipment.

Applicants have as a further object of their invention the provision of a burner with a filtering arrangement for the complete removal of entrained uranium or other element from the gases of combustion.

Applicants have as a still further object of their invention the provision of a burner which may be quickly and easily charged with material and from which the ash may be separated and easily removed.

Other objects and advantages of our invention will appear from the following specification and accompanying drawing, and the novel features thereof will be particularly pointed out in the annexed claims.

The sole figure shows a front elevation, partly in section, of our improved burner.

Referring to the drawing in detail, 1 designates a vertical cylinder of nickel or other appropriate material having a flange 17 on its upper end for cooperation with a mating flange 18 on a cover 2 which is of conical configuration. The two flanges are frictionally maintained in sealed abutting relation by a series of

resilient clips

19, 19 carried by the cover 2 and adapted to extend over the edges of the flanges at a seriesof spaced positions along the circumference. Extending upwardly at an angle from the cover 2 is a tubular extension 20 which is externally screw threaded to engage a threaded cap 10 for maintaining it in position. The cap 10 acts as a closure and carries a glass sight, or window, in its upper end to permit visual examination of the contents of the burner during combustion. Oxygen or air is supplied to the burner through a tubular extension 3 which enters the apex of the conical cover 2.

Cylinder 1 is closed at its lower end by an inverted conical shell 4 of nickel or other appropriate material. This shell serves as a base for the burner. Joined to the lower end of the shell 4 at the apex and projecting downward therefrom is an extension 5 of nickel or other appropriate material, externally screw threaded at its lower end for cooperation with the internal screw threads of cap 6. Cap 6 is removable so that the burner can be rinsed out quantitatively. Positioned in the lower end of cylinder 1 and resting upon the cone 4 at the juncture of the base or cone 4 with the cylinder 1 is a grate 11 made of a carbon disk containing a series of spaced holes. The grate is adapted to receive and support the pieces of carbon to be burned. Joined integrally and opening into cone or base 4 with an axis at about 60 from the vertical is cone 7 whose upper end merges into a cylindrical section 9. The upper end of the cylindrical section 9 terminates in a flanged portion 21 for cooperation with a mating flanged portion or flange 22 on conical cover 15. Spring fingers or clips 23 carried by cover 15 and spaced about the circumference of flange 22 at convenient intervals engage over the edges of the

abutting flanges

21, 22, to retain the cover 15 on the cylindrical section 9 in tight sealed relation. The cover 15 mounts a nipple or an-enlargement defining a socket at its apex, and this nipple or socket serves as an outlet for connection to the manifold of a Cottrell or other electrostatic precipitator. Positioned in the cylindrical section 9 is a perforated bafile 12 having converging

arms

13, 14 extending downwardly therefrom for engagement with the tapering inner walls of the conical portion 7 for supporting the bafile in an intermediate position within the cylindrical section 9. Packed in the upper part of the cylindrical section 9 and resting on the perforated baflle 12 is a barrel 16 of glass wool to provide filtering action for the removal of entrained uranium or other element or elements from the gases of combustion as they pass on out to the Cottrell precipitator.

Above the glass wool and closing the upper end of the cylindrical section 9 is a glass cloth filter 8. This filter is preferably supported by having its circumferential portions clamped between the

flanges

21 and 22.

Wrapped, preferably in spiral form, about the outer surfaces of the portions of the burner is copper or other appropriate tubing 26 through which water or other cooling media may be passed to cool the walls of the burner by heat transfer. The rigidity of the structure may be increased by bridging the

cylindrical portions

1, 9, with braces or cross members 27, having their end portions Welded or otherwise secured to the cylindrical sections of the burner.

In the operation of the burner, it is first cleaned thoroughly. Bafile 12, glass wool barrel 16, filter cloth 8, and grate 11 are placed in position. Cover 15 is clamped over open end of cylindrical section 9, and drain cap 6 is screwed up tight. The carbon to be burned is then broken into pieces approximately 2 inches square and placed in the cylindrical section 1 of the burner. The cooling water is then turned on and the carbon is ignited by lighting a wad of filter paper and closing the lid, oxygen being supplied through line 3. As the gases resulting from combustion expand into the large cross section of cone 7 and cylindrical section 9, any ash carried by the slow escaping gases is filtered out by the glass wool barrel 16 and filter cloth 8. Furthermore, the resistance of the glass Wool packing in section 9 maintains the oxygen-carbon monoxide ratio above the explosive limit of the burner.

After combustion is completed, lid 2 is removedand carbon grate 11 is taken out to be used in the next batch. Filter cloth 8 and glass wool barrel 16 are carefully removed and after drain cap 6 is unscrewed, the inside of the burner is thoroughly Washed down with .water or leached with nitric acid and the wash is received in a beaker placed, under the drain. This leachingaction producesa solution of a nitrate or nitrates of the elements to be recovered. An element, such as uranium, may be recovered from this solution by various methods including solvent extraction, evaporation, precipitation or other common methods; For example, in the case of uranium, a salting out agent such as copper nitrate may be added, and the resulting solution may then be extracted with an ether, such as diethyl-ether.

Having thus described our invention, we claim:

1. A burner of the character described comprising an elongated combustion chamber, a grate positioned in said combustion chamber near its lower extremity to support a charge of material, means for feeding oxygen into the upper extremity of the combustion chamber to support combustion of the charge, a gas expansion chamber having its lower extremity in communication with the combustion chamber below the grate, means for removing gases of combustion from the expansion chamber, and a filter positioned in the upper extremity of the expansion chamber for removing entrained particles of charge material from the gases of combustion.

2. A carbon burner of the character described comprising an elongated body defining a combustion chamber, a removable cover for the upper end of the body to permit insertion of a carbon charge, a grate positioned in the lower extremity of the body for supporting the charge, a duct extending into the cover for feeding oxygen into the combustion chamber, a gas expansion chamber for communication with the combustion chamber at a position beneath the grate, and a filter positioned in the expansion chamber for removing entrained particles of charge material from the gases of combustion.

3. A carbon burner of the character described comprising an elongated substantially cylindrical body dc fining a combustion chamber, a removable cover for the body to permit insertion of a carbon charge, a line leading through the cover and into said combustion chamber for supplying oxygen, a grate positioned in the lower portion of the combustion chamber for supporting the charge, a gas expansion chamber for communication with the combustion chamber at a position beneath the grate for the passage of the gases of combustion, and a glass wool filter disposed Within the expansion chamber for removing entrained particles of charge material from the gases of combustion.

4. A carbon burner of the character described comprising an elongated tubular body portion defining a combustion chamber, said body portion terminating at its lower end in a conical portion for collecting residue from the combustion chamber, a cover for the upper end of said body portion to permit the insertion of a carbon charge, means for feeding oxygen into said combustion chamber through said cover, a grate positioned in the lower part of said chamber for supporting the charge, an expansion chamber for communication with the combustion chamber beneath said grate for the passage of gases of combustion, and a plurality of filters disposed within the expansion chamber for the removal of entrained particles in the combustion gases.

5. A carbon burner of the character described comprising an elongated tubular body portion defining a combustion chamber, said body portion terminating at its lower end in a frusto conical portion, a cover for the upper end of said body portion to permit the insertion of a carbon charge, means for feeding oxygen into said combustion chamber through said cover, a grate positioned in the lower part of said chamber for supporting the charge, a removable cap on a frusto conical portion for removing residue from the chamber, an expansion chamber for communication with the combustion chamber beneath said grate for the passage of gases of combustion, a plurality of filters disposed within the expansion chamber for, the removal of entrained particles in the combustion gases, and cooling tubes disposed about the tubular body to limit the rise in temperature thereof.

References Cited in the file of this patent UNITED STATES PATENTS 3,853 Bradley Oct. 12, 1844 154,173 Hauberg Aug. 18, 1874 310,920 Spear et a1. Ian. 20, 1885 584,344 Geradin et a1. June 15, 1897 1,076,942 Backmire Oct. 28, 1913 1,961,424 Maier June 5, 1934 2,247,334 Keemle June 24, 1941 FOREIGN PATENTS 2,086 Great Britain Jan. 28, 1903 4,667 Great Britain Feb. 25, 1909

Claims

1. A BURNER OF THE CHARACTER DESCRIBED COMPRISING AN ELONGATED COMBUSTION CHAMBER, A GRATE POSITION IN SAID COMBUSTION CHAMBER NEAR ITS LOWER EXTREMITY TO SUPPORT A CHARGE OF MATERIAL, MEANS FOR FEEDING OXYGEN INTO THE UPPER EXTREMITY OF THE COMBUSTION CHAMBER TO SUPPORT COMBUSTION OF THE CHARGE, A GAS EXPANSION CHAMBER HAVING ITS LOWER EXTREMITY IN COMMUNICATION WITH THE COMBUSTION CHAMBER BELOW THE GRATE, MEANS FOR REMOVING GASES OF COMBUSTION FROM THE EXPANSION CHAMBER, AND A FILTER POSITIONED IN THE UPPER EXTREMITY OF THE EXPANSION CHAMBER FOR REMOVING ENTRAINED PARTICLES OF CHARGE MATERIAL FROM THE GASES OF COMBUSTION.