RU2145306C1 - Device for production of plutonium compounds - Google Patents

Abstract

FIELD: chemical, metallurgical and other branches of industry. SUBSTANCE: device has vertical and horizontal components connected at a right angle, with a filter and hopper casing in the vertical component, discharging device with a plug valve, the hopper casing with the discharge basket have a horizontal axle, and the basket consists of longitudinal ribs covered from the outside by a woven wire net; on the one side the basket is attached to the horizontal axle linked by an independent drive. The device horizontal component accommodates an agitating member made up of one or several longitudinal ribs adjoining the inner surface over its entire length. The agitating member is linked by an independent drive. The device is made for movement of the drive part by a screw mechanism up and down relative to the vertical axis. EFFECT: combined processes of production of powder from compact material and its further processing. 3 cl, 3 dwg

Description

 The invention relates to the field of chemical engineering, and in particular to apparatus for producing bulk radioactive materials from a compact metal state and processing them with gas. The invention can be used in the chemical, metallurgical and other industries.

 Due to the reduction of strategic weapons in Russia and the United States, large quantities of compact weapons-grade plutonium are being released, which can be used to produce fuel elements for energy nuclear reactors or its compounds as a component for MOX - fuel, mononitride, and other fuel compositions.

 To obtain various plutonium compounds by the anhydrous method, it is necessary to transfer it from a compact state to a fine powder with a certain particle size.

 Apparatuses for crushing and grinding bulk material into a powder state are known in the industry: crushers, mills, dismembrators, disintegrators, etc. (Kasatkin A.G. "Basic processes and apparatuses of chemical technology" M., Chemistry, 1973, 750 pp.).

 These devices are not suitable for crushing and grinding a compact radioactive material, for example, plutonium due to the large dust emission and the inability to maintain safe geometric dimensions. In the chemistry of plutonium, hydrogenation processes are used to transfer it from a compact state to powder. ("Metallurgy and metallurgy of plutonium and its alloys", edited by Wilkinson, U. D., M., Goskomizdat, 1962, 274 pp., "Metallurgy of plutonium" Volsky A. N., Sterlin Y. M., M., Science, 1967, 250 pages, US patent N 1373896, C 01 G, 56/00). The disadvantages of the above devices include a significant duration in time and low productivity.

 To transfer bulk material into other compounds by the anhydrous method using a reagent gas, tubular devices with a horizontal or vertical axis and internal elements are used to mix and move the material towards the reagent gas stream. Examples of such devices with a horizontal axis are devices of the RF type (fluorination reactor) used to produce uranium fluorides and rare-earth elements (Galkin A.N. Mayorov A.A., Veryatin U.D. et al. "Chemistry and technology of fluoride compounds uranium ", - M., Gosatomizdat, 1961, 348 pp.). Fluidized bed apparatuses are also known, but they are also not suitable for processing radioactive materials because of the significant dust extraction and large volumes of exhaust gases.

 As a prototype, a device for carrying out hydrogenation and hydrochlorination reactions depicted in FIG. 1. ("Plutonium metallurgy", Volsky A.N., Sterlin Y.M., -M.: Nauka, 1967, 148 pp.).

 The device is made of pyrex glass and has a glass thin section 1, clamp 2, fastening tube, thermocouple 3, fitting 4 for supplying hydrogen and hydrogen chloride, as well as for connecting to a vacuum installation, thermocouple 5 for adjusting the temperature of the furnace, pyrex tube 6 with a diameter of 50, 8 mm, coarse pyrex filter 7, nozzle 8 for connection to a water aspirator. The fittings 4 and 8 are located horizontally, and the filter 7, located in the lower part of the vertical tube 6 serves as a fixed support for the processed product.

 During the hydrogenation operation, the nozzle 8 is plugged. After the conversion of plutonium into plutonium hydride, hydrogen chloride is supplied into the nozzle 4, and the nozzle 8 is connected to a water aspirator and plutonium chloride is obtained.

 This device does not allow loading and unloading of the product without its complete disassembly. The processes of transferring a product from a compact state and its subsequent treatment with a reagent gas are carried out on one fixed supporting surface, which simultaneously acts as an exhaust gas filter, which can lead to clogging of the filter pores, since the surface is not cleaned. The size of the resulting particles is not regulated. The process of processing the product with a reagent gas in a fixed bed takes a very long time due to poor mass transfer; the consumption of a reagent gas increases.

 The proposed device allows for loading and unloading of the product without disassembling it, improving the quality of mass transfer by separating the processing sites and mechanical activation of the processes by providing a hopper body in the vertical part of the device, in which a receiving basket is located, which has a common horizontal axis and the body consisting of longitudinal ribs covered outside with a woven wire mesh and in the horizontal part a mixing element consisting of one or more longitudinal ribs adjacent to the inner surface of the horizontal part along its entire length. The basket and the mixing element are fixed on one side on different horizontal axes associated with independent drives. The screw mechanism allows you to move the device up - down relative to the vertical axis. Depending on the replacement of the reagent gas, various compounds (oxides, fluorides, hydrides, nitrides, etc.) can be obtained from plutonium powder.

 The device shown in FIG. 2, consists of vertical and horizontal parts connected at right angles. The geometric dimensions of the device are determined by the physicochemical properties of the starting product. In the upper part of the vertical pipe is placed a filter 1 for cleaning exhaust gases, below it is the body of the hopper 2, in which there is a receiving basket 3 with a horizontal axis, rotated by an independent drive. A cover 4 is provided on one side of the hopper body for loading compact plutonium. The receiving basket is made of several longitudinal ribs 5, connected at the ends and fitted on the outside with a wire woven mesh 6, the cells of which determine the amount of grinding material. The section of the basket in FIG. 3.

 In the horizontal part of the device, a mixing element 7 is located inside, representing one or more longitudinal ribs 8 adjacent to the inner surface of the housing and rotated by an independent drive. At the end of the horizontal part there is an unloading hatch with a receiving capacity of 9 and a cone lock 10, which opens when unloading. The proposed device is made with the possibility of moving the drive part by a screw mechanism 11 up and down relative to the vertical axis 12. The device is equipped with independent electric heaters 13 and 14 with thermal insulation of the outer part. The device is made in a nuclear-safe geometry of a corrosion-resistant material (nickel or its alloys).

The device operates as follows. When plutonium 4 is removed, compact plutonium is put into the receiving basket 3. Electric heaters 13 and 14 are turned on, and when the desired temperature is reached, the target gas is supplied — a reagent acting on compact plutonium. The metal swells from the surface, forms films, which, when the basket rotates from the drive, break off with ribs, freeing up a clean surface for further reaction with gas. Small pieces of film quickly react with gas, crushing to sizes that allow them to enter the horizontal part of the device through the cells of the grid 6. Stirring the powder during rotation, the ribs 8 evenly distribute it along the length of the horizontal part. A closed conical shutter prevents the material being processed to wake up in the receiving tank 9. The process continues until the compact material completely breaks into powder. Replacing the reactant gas with another, constantly mixing the powder, we obtain the necessary powdery compound. Unloading is carried out by tilting the horizontal axis towards the receiving tank using a screw mechanism 11 and, by turning the handle of the cone shutter 10 by 180 ^° , thereby opening the outlet of the processed material into the tank by rotating the ribs 8. Replacing the tank, the process can be repeated.

Claims (3)

 1. A device for producing powdered plutonium compounds, consisting of vertical and horizontal parts connected at right angles to the filter and the hopper body in the vertical part, characterized in that the hopper body with the receiving basket have a horizontal axis, and the basket consists of longitudinal ribs, wrapped outside with a woven wire mesh, and the basket on one side is fixed on a horizontal axis associated with an independent drive, and in the horizontal part there is a discharge device with a conical Shutter and mixing element.  2. The device according to claim 1, characterized in that the mixing element consists of one or more longitudinal ribs adjacent to the inner surface of the horizontal part of the device along its entire length, and the mixing element is fixed on one side on a horizontal axis associated with an independent drive.  3. The device according to claim 1, characterized in that it is arranged to move the drive part with a screw mechanism up and down relative to the vertical axis.

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