JP4594001B2 - Apparatus for producing ammonium biuranium particles and method for producing the same - Google Patents

Description

  The present invention relates to an ammonium heavy uranate particle manufacturing apparatus and a manufacturing method thereof, and more particularly to an ammonium heavy uranate particle manufacturing apparatus and a manufacturing method thereof capable of obtaining ammonium heavy uranate particles having a uniform mass.

  A fuel for a HTGR is generally manufactured through the following processes. First, uranium oxide powder is dissolved in nitric acid to obtain a uranyl nitrate stock solution containing uranyl nitrate. Next, pure water, a thickener, etc. are added to this uranyl nitrate stock solution and stirred to prepare a dripping stock solution containing uranyl nitrate. The prepared dropping undiluted solution is cooled to a predetermined temperature, adjusted in viscosity, and then dropped into an aqueous ammonia solution using a small-diameter dropping nozzle.

  The droplets dropped onto the aqueous ammonia solution are sprayed with ammonia gas before reaching the surface of the aqueous ammonia solution. The surface of the droplet is gelled by the ammonia gas, thereby preventing deformation when reaching the surface of the aqueous ammonia solution. Uranyl nitrate in the aqueous ammonia solution sufficiently reacts with ammonia to become ammonium heavy uranate particles (hereinafter sometimes abbreviated as “ADU particles”).

  The ADU particles are dried and then roasted in the air to become uranium trioxide particles. Further, the uranium trioxide particles are reduced and sintered to become high-density ceramic uranium dioxide particles. The uranium dioxide particles are screened, that is, classified to obtain fuel core fine particles having a predetermined particle size (see Non-Patent Document 1).

  However, in order to improve the production amount of ammonium heavy uranate particles, the conventional apparatus for producing ammonium heavy uranate particles has a plurality of dropping stock solution supply nozzles, and in the ADU particles falling from any of the dropping stock solution supply nozzles In order to have the same constant mass, it is necessary to make the flow rate of the dropping stock solution dropped from each dropping stock solution supply nozzle constant. For this purpose, a flow controller is provided to keep the dropping amount of the dropping stock solution constant. With this flow controller alone, it is difficult to keep the flow rate of the dripping stock solution constant, so that there is a problem that the particle diameters of the formed ammonium heavy uranate particles are uneven.

Hasegawa Masayoshi, Mishima Yoshimi supervision "Reactor Material Handbook", published on October 31, 1977, pages 221-247, Nikkan Kogyo Shimbun

  This invention solves the problems of the prior art and provides an ammonium heavy uranate particle production apparatus and an ammonium heavy uranate particle production method capable of forming ammonium heavy uranate particles having a uniform mass. Let that be the issue.

As means in this invention for solving the above-mentioned problems,
According to a first aspect of the present invention, a plurality of nozzles, a light irradiation means for irradiating light onto a uranyl nitrate-containing liquid droplet falling from each of the plurality of nozzles, and a drop state of the liquid droplet irradiated by the light irradiation means An apparatus for producing ammonium biuranate particles, characterized by having a flow controller for adjusting the supply amount of a dripping stock solution containing uranyl nitrate to each nozzle,
Claim 2 is the ammonium deuterated uranate particle producing apparatus according to claim 1, wherein the light irradiation means is a strobe light irradiation means for irradiating periodically flashing light.
According to a third aspect of the present invention, the optical sensor that detects the light emitted from the light irradiation unit and the detection signal output from the optical sensor are input so that the amount of droplets dropped from each nozzle is the same. And a control means for controlling the flow rate regulator, wherein the ammonium biuranium particle production apparatus according to claim 1,
According to a fourth aspect of the present invention, the uranyl nitrate-containing liquid droplets dropped from a plurality of nozzles are irradiated with periodically flashing light by the stroboscopic light irradiation unit, and the liquid droplets irradiated by the stroboscopic light irradiation unit are in a dropping state. In accordance with this, it is an ammonium heavy uranate particle production apparatus characterized by adjusting the amount of uranyl nitrate-containing dripping stock solution supplied to each nozzle,
According to the fifth aspect of the present invention, the uranyl nitrate-containing droplets falling from each of the plurality of nozzles are irradiated with light by the light irradiating means, and the uranyl nitrate-containing dripping solution to each nozzle according to the falling state of the irradiated droplets The method for producing ammonium deuterated uranium particles is characterized in that the supply amount of uranium is adjusted.

  In this invention, the dripping stock solution containing uranyl nitrate is supplied to a plurality of nozzles. The dropping stock solution is continuously dropped from a plurality of nozzles. Light is irradiated to the dripping stock solution continuously dripped by a light irradiation means. The falling state of the droplet irradiated with light is detected visually or with a light sensor, and the weight of the droplet falling from each nozzle is adjusted by adjusting the flow rate controller according to the falling state of the droplet. . As a result, the weight of the liquid droplets falling from each nozzle can be made uniform.

  When the drop state of the liquid droplets irradiated with the light irradiation means is detected by the optical sensor, the optical sensor is arranged for each liquid droplet column dropped from each nozzle.

  When a droplet falls in a state where light is irradiated by the light irradiating means, the light is blocked by the droplet, so the optical sensor outputs a detection signal to the control means. The control means determines whether or not the droplet blocks the light reaching the photosensor at the same time based on the detection signal output from the photosensor arranged for each droplet row, and the droplet By measuring the time for blocking, it is determined whether the drop state of a droplet falling from which nozzle is different from the drop state of a droplet falling from another nozzle. The control means automatically controls the flow rate regulator so that any droplet falling from each nozzle falls at the same timing.

  When the light irradiation means is a strobe light irradiation means, the flow rate controller is controlled as follows.

  In the same manner as described above, the liquid droplets dripped from the nozzle are irradiated with periodically flashing light (also referred to as strobe light) by the strobe light irradiation means that is the light irradiation means. When a plurality of droplets sequentially dropped from the nozzle are irradiated with the strobe light, the plurality of droplets dropped from the nozzle are observed as if they were stationary. When it is observed that all the droplets dropped from the plurality of nozzles at the same timing are at the same height position, the plurality of nozzles have the same shape and dimensions, and thus are dropped from the plurality of nozzles. It can be determined that all the droplets have the same concentration, the same particle size, and the same weight. However, when it is observed that the plurality of droplets dropped from the plurality of nozzles at the same timing are not at the same height position, it is determined that the particle sizes and weights of the plurality of droplets dropped from the plurality of nozzles are different. Is done. At that time, the supply amount of the dropping stock solution supplied to the nozzles is adjusted by operating the flow rate regulator, and all the droplets are dropped from the plurality of nozzles with the same weight and the same particle size at the same timing. Become so.

  Therefore, according to the present invention, an ammonium heavy uranate particle production apparatus (hereinafter sometimes referred to as an ADU particle production apparatus) capable of easily producing ADU particles having a uniform mass and particle diameter, and production thereof. A method can be provided.

  FIG. 1 shows an example of an apparatus for producing ammonium heavy uranate particles according to the present invention. The ADU particle manufacturing apparatus according to the present invention is not limited to the apparatus shown in FIG. As shown in FIG. 1, the ammonium heavy uranate particle manufacturing apparatus 1 includes a nozzle device 2A including a plurality of nozzles 2, a vibrator 3, a strobe light irradiation unit 4 as an example of a light irradiation unit, and a flow rate. A regulator 7, a dropping stock solution supply pipe 8, a separator 9, a pump 10, a dropping stock solution storage tank 11, and a reaction tank 12 are provided.

  The nozzle 2 is a nozzle for dripping the dripping stock solution fed through the dripping stock solution supply pipe 8 into the aqueous ammonia solution stored in the reaction tank 12.

  The nozzle device 2A is configured by arranging a plurality of nozzles 2 in a horizontal row so that one end of each nozzle 2 is directed downward and the axis of the nozzles 2 is parallel. The plurality of nozzles 2 all have the same structure. When the nozzle 2 is a tubular body, the plurality of nozzles 2 are all formed of the same opening diameter, the same axial length, and the same material. That is, the plurality of nozzles 2 are designed to have the same conditions for dropping the dropping stock solution.

  The material of the nozzle 2 may be any material having excellent corrosion resistance, heat resistance and impact resistance, such as glass, stainless steel, aluminum, magnesium, zirconium, aluminum alloy, magnesium alloy or zirconium alloy. Can be mentioned.

  Examples of the cross-sectional shape of the nozzle 2 include a circle, an ellipse, a polygon, and the like, and a circle is particularly preferable.

  Moreover, it is preferable that the internal diameter of the said nozzle 2 is 0.1-6 mm, and it is especially preferable that it is 0.1-2 mm.

  If the inner diameter is less than 0.1 mm, the nozzle may be clogged. On the other hand, if the inner diameter is larger than 6 mm, it is difficult for the droplets to fall from the nozzle tip due to the surface tension of the dripping stock solution. As a result, the droplets become large at the tip, and the size of the formed ADU particles may become too large.

  The number of the nozzles 2 is preferably 2 to 32, and particularly preferably 4 to 16.

  Further, the plurality of nozzles 2 are preferably arranged in a horizontal row as described above, and in some cases, the projected tip when the tip of the nozzle 2 is projected onto a horizontal plane is circular, elliptical, or square. A plurality of nozzles 2 may be arranged in such a row.

  This nozzle device 2 </ b> A is arranged above the reaction tank 12 so that a droplet falls on the central portion of the reaction tank 12 in the horizontal cross section. Each of the plurality of nozzles 2 has a dripping stock solution supply pipe 8 coupled to the other end. A vibrator 3 is attached to the nozzle device 2A. The vibrator 3 is formed so as to vibrate a plurality of nozzles 2 at a constant frequency simultaneously by applying a vibration having a constant frequency to the entire nozzle device 2A.

  As the vibrator 3, a vibration generator such as a vibration motor can be used.

  The frequency of vibration by the vibrator 3 is preferably 50 to 200 Hz.

  When the frequency is lower than the above range, the droplet does not fall from the tip of the nozzle 2, and the droplet grows at the tip of the nozzle 2, and as a result, the ADU having a desired size is obtained. Particles may not be obtained. In addition, when the frequency is higher than the above range, the aqueous ammonia solution stored in the reaction tank 12 is reached before the droplet becomes spherical, and ADU particles having a desired shape cannot be obtained. There is.

  The strobe light irradiation means 4 irradiates the light dropped periodically from the nozzle 2 with light that periodically blinks.

  Examples of the strobe light irradiation means 4 include a strobe discharge tube.

  The strobe light irradiation means 4 is preferably arranged at a position where a droplet dropped from the nozzle 2 can be irradiated.

  As the flow rate regulator 7, a known flow rate regulator can be adopted as long as the flow rate of the dropping stock solution supplied to the nozzle 2 can be adjusted. In this example, it is interposed in the middle of the dropping stock solution supply pipe 8. But there is no restriction | limiting in particular as a position where this flow regulator 7 is arrange | positioned.

  The flow rate of the dropping stock solution adjusted by the flow rate controller 7 is appropriately determined according to the weight of the droplet dropped from the nozzle 2 and the viscosity of the dropping stock solution.

  One end of a dropping stock solution supply pipe 8 provided with the flow rate regulator 7 is coupled to the nozzle 2, and the other end is connected to a dropping stock solution storage tank 11 via a separator 9 and one pump 10 as shown in FIG. The Further, without using the separator 9, each dripping stock solution supply pipe 8 can be connected to the dripping stock solution storage tank 11 via a pump provided in each dripping stock solution supply pipe 8.

  The dripping stock solution supply pipe 8 is preferably a pipe having chemical resistance and corrosion resistance and having flexibility in the vicinity of the nozzle 2.

  Examples of the material of the dripping stock solution supply pipe 8 include inorganic materials such as stainless steel, aluminum, and aluminum alloys, or polymer materials such as polyethylene resin, polystyrene resin, polytetrafluoroethylene resin, natural rubber, and butyl rubber. It may be used alone or in combination of two kinds.

  The pump 10 is a pump that supplies the dripping stock solution stored in the dripping stock solution storage tank 11 to the nozzle 2 via the flow rate regulator 7 and the dripping stock solution supply pipe 8.

  As the pump 10, a known pump can be used.

  The dripping stock solution storage tank 11 is a tank that stores a dripping stock solution. In some cases, the dripping stock solution may be prepared and stored in the dripping stock solution storage tank 11.

  The material of the dripping stock solution storage tank 11 may be any material having chemical resistance and corrosion resistance. For example, inorganic materials such as stainless steel, aluminum, aluminum alloy, titanium alloy, polyethylene resin, polystyrene resin, poly Examples thereof include polymer materials such as vinyl chloride resin and polyfluoroethylene resin.

  The volume and shape of the dripping stock solution storage tank 11 are not particularly limited, and can be appropriately determined according to the production amount of ADU particles to be formed.

  Using the ADU particle production apparatus 1 according to the present invention, ADU particles can be produced as follows.

  The dripping stock solution prepared to a predetermined concentration is supplied to the dripping stock solution storage tank 11.

  The dripping stock solution is supplied to each dripping stock solution supply pipe 8 by the pump 10 via the separator 9.

  Then, the dropping stock solution passes through the flow rate regulator 7 and is dropped into the aqueous ammonia solution stored in the reaction tank 12 from the nozzle 2 that is vibrated by the vibrator 3.

  The dropped liquid droplets are irradiated with periodic light by the strobe light irradiation means 4 disposed between the nozzle 2 and the reaction tank 12.

  When the stroboscopic light irradiating means 4 irradiates the droplets from which the stroboscopic light falls, as shown in FIG. 2, the plurality of droplets falling from the nozzle 2 are visually observed as if they were stationary. For example, as shown in FIG. 2, droplets falling from a plurality of nozzles 2 arranged in a horizontal row with vertical axes parallel to each other instantaneously form a line from the tip of each nozzle 2 by strobe light. The state of falling is visually observed as if fixed.

  If the droplets falling from all the nozzles 2 have the same particle size and volume, and the droplets drop simultaneously from all the nozzles 2, the droplets falling from all the nozzles 2 are observed in a horizontal row. Is done. If any of the droplets falling from the nozzle 2 at the same timing is visually observed in a state where they are not arranged in a horizontal row, the droplets that are not in a horizontal row are heavier than the other droplets. It can be judged that it is large or small.

  Therefore, the flow rate of the dripping stock solution supplied to the nozzle 2 is finely adjusted by operating the flow rate regulator 7 in the dripping stock solution supply pipe 8 coupled to the nozzle 2 that drops the liquid droplets that are not in a horizontal row. When the droplets falling from all the nozzles 2 are observed in a horizontal row, the fine adjustment of the flow rate is finished.

  In this way, it is possible to determine whether or not the droplets dropped from all the nozzles 2 are the droplets of the same weight by simply irradiating the droplets dropped from the plurality of nozzles 2 with strobe light. In addition, the droplets dropped from all the nozzles 2 can be easily adjusted so that the droplets have the same weight.

  According to the ammonium heavy uranate particle production apparatus shown in FIG. 1, it is possible to easily adjust all the droplets dropped from all the nozzles 2 to have the same weight.

  Since all the droplets adjusted to the same weight dropped from all the nozzles 2 are dropped into the aqueous ammonium solution stored in the reaction vessel, uniform weight ammonium biuranate particles are formed in this reaction vessel. Is done.

  Next, another example of the present invention will be shown.

  The ammonium heavy uranate particle manufacturing apparatus shown in FIG. 3 is different from the ammonium heavy uranate particle manufacturing apparatus shown in FIG. 1 in that continuous irradiation light is irradiated instead of the strobe light irradiation means 4 as light irradiation means. The continuous light irradiation means 4A, a plurality of photosensors such as the photoelectric conversion elements 5 disposed opposite to the continuous light irradiation means 4A across the drop trajectory of the droplets dropped from the nozzles 2, and the plurality of photoelectric conversion elements 5 The delay of any one of the droplets dropped from the plurality of nozzles 2 is measured on the basis of the light detection signal output from each of the nozzles 2, and each flow rate adjustment provided in the dropping stock solution supply pipe 8 connected to each nozzle 2 And a controller 6 for outputting a drive control signal to the device 7.

  The plurality of photoelectric conversion elements 5 includes a number of photoelectric conversion elements 5-1, 5-2 to 5-8 equal to the number of the plurality of nozzles 2.

  As the photoelectric conversion element, a known element can be used, and examples thereof include CdS, PbS, PbSe infrared sensor, phototransistor, photodiode, amorphous Se, and amorphous Si.

  Each of the photoelectric conversion elements 5-1 to 5-8 is, for example, as shown in FIG. On the side opposite to the light source 20, each droplet 21 is disposed for each falling locus. When the liquid droplets do not pass between the light source 20 and the photoelectric conversion elements 5-1 to 5-8, each of the photoelectric conversion elements 5-1 to 5-8 outputs a detection signal of constant output A that has been photoelectrically converted. When the liquid droplet passes between the light source 20 and the photoelectric conversion elements 5-1 to 5-8, light whose intensity is reduced by the amount absorbed by the liquid droplets is supplied to the photoelectric conversion elements 5-1 to 5-8. The photoelectric conversion elements 5-1 to 5-8 are photoelectrically converted and output a detection signal of an output B that is lower than the output A. Therefore, it is detected by the detection signals output from the photoelectric conversion elements 5-1 to 5-8 that the liquid droplets have passed between the light source 20 and the photoelectric conversion elements 5-1 to 5-8.

  Detection signals output from the photoelectric conversion elements 5-1 to 5-8 are output to the control unit 6. The control unit 6 distinguishes signals output from the photoelectric conversion elements 5-1 to 5-8. For example, the detection signal output from the photoelectric conversion element 5-1 is a continuous signal having a constant voltage when no droplet passes between the light source 20 and the photoelectric conversion element 5-1. When the dropped liquid droplet is positioned between the photoelectric conversion element 5-1, the output of the detection signal output from the photoelectric conversion element 5-1 is lowered. The controller 6 cuts out the input output decrease detection signal and converts it into a positive pulse signal as shown in FIG.

  When the droplets are intermittently dropped from the nozzle 2, the droplets periodically pass between the light source 20 and the photoelectric conversion element 5-1. Therefore, in the control unit 6 that receives the detection signal output from the photoelectric conversion element 5-1, the detection signal continuously output from the photoelectric conversion element 5-1, as shown in FIG. Recognized as a pulse signal. Similarly, the control unit 6 recognizes the detection signals output from the photoelectric conversion elements 5-2 to 5-8 as a series of continuous pulse signals.

  If all the droplets that fall simultaneously from the tips of the plurality of nozzles 2 have the same weight, all the droplets simultaneously pass between the light source 20 and the photoelectric conversion elements 5-1 to 5-8. Therefore, in the control unit 6, as shown in FIG. 5, the pulse signals for the photoelectric conversion elements 5-1 to 5-8 are simultaneously detected and synchronized.

  Here, for example, when the weight of a droplet dropped from a certain nozzle 2 out of a number of nozzles is different from the weight of a droplet dropped from another nozzle 2, the control unit 6 performs As shown in FIG. 6, the pulse signal for the photoelectric conversion element 5-2 is detected later than the pulse signals for the other photoelectric conversion elements 5-1, 5-3 to 5-8.

  When the control unit 6 detects that the pulse signal for the photoelectric conversion element 5-2 is delayed from the pulse signals for the other photoelectric conversion elements 5-1, 5-3 to 5-8, FIG. As shown, it is determined that the dropping state of the nozzle 2 that drops a droplet passing between the photoelectric conversion element 5-2 and the light source 20 is abnormal. When the control unit 6 detects an abnormality in the nozzle 2 with respect to the photoelectric conversion element 5-2, the control unit 6 outputs a drive control signal to the flow rate regulator 7, and the flow rate regulator 7 that inputs this drive control signal causes the nozzle to The supply amount of the dropping stock solution supplied to 2 is adjusted.

  Control by the flow rate regulator 7 is performed until the pulse signal for the photoelectric conversion element 5-2 detected by the control unit 6 is synchronized with the pulse signals for the other photoelectric conversion elements 5-1, 5-3 to 5-8. Control that continues to output the drive control signal to the flow rate regulator 7 and the relationship between the time difference between the pulse signal for the photoelectric conversion element 5-2 and the pulse signal for the other photoelectric conversion element and the control amount in the flow rate regulator 7 Is stored in the memory in advance, and the control amount of the flow rate regulator 7 is determined by applying the delay of the pulse signal for the photoelectric conversion element 5-2 to the calibration curve in the memory, and the flow rate regulator 7 may be any control that outputs a predetermined control signal.

  With the ammonium heavy uranate particle production apparatus provided with the control unit 6 described above, it is possible to automatically adjust and control the weight of droplets dropped from a plurality of nozzles. Therefore, according to this ammonium heavy uranate particle manufacturing apparatus, it is possible to manufacture ammonium heavy uranate particles having no variation in weight.

  As described above, an example of an apparatus for producing ammonium heavy uranate particles according to the present invention has been described, in particular, an apparatus for uniformizing the weight of droplets dropped from a plurality of nozzles manually or automatically without variation.

FIG. 1 is an explanatory view showing an example of an ADU particle production apparatus according to the present invention. FIG. 2 is a view showing a droplet whose height is kept constant by the ADU particle manufacturing apparatus according to the present invention. FIG. 3 is an explanatory view showing another example of the ADU particle production apparatus according to the present invention. FIG. 4 is an explanatory diagram showing a light source, a photoelectric conversion element, and a control unit in the ADU particle manufacturing apparatus shown in FIG. FIG. 5 is an explanatory diagram showing a pulse signal sequence detected when droplets of the same weight are falling synchronously from each nozzle in the ADU particle manufacturing apparatus shown in FIG. FIG. 6 is an explanatory diagram showing a pulse signal sequence detected when droplets of different weights are falling out of synchronization from the nozzles in the ADU particle manufacturing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ADU particle manufacturing apparatus 2 Nozzle 3 Vibrator 4 Strobe light irradiation means 5 Photoelectric conversion element 5-1 to 5-8 Photoelectric conversion element 6 Control part 7 Flow controller 8 Dripping stock solution supply pipe 9 Separator 10 Pump 11 Dripping stock solution storage tank 12 Reaction tank 20 Light source 21 Droplet

Claims (5)

  A plurality of nozzles, a light irradiating means for irradiating light onto uranyl nitrate-containing droplets falling from each of the plurality of nozzles, and depending on the drop state of the droplets irradiated by the light irradiating means, to each nozzle The apparatus for producing ammonium heavy uranate particles, comprising a flow controller for adjusting a supply amount of a dripping stock solution containing uranyl nitrate.   The apparatus for producing ammonium heavy uranate particles according to claim 1, wherein the light irradiation means is a strobe light irradiation means for irradiating periodically flashing light.   The flow rate controller is controlled so that the amount of liquid droplets dropped from each nozzle is the same by inputting a detection signal output from the optical sensor that detects light emitted from the light irradiation means and the optical sensor. The apparatus for producing ammonium heavy uranate particles according to claim 1, further comprising:   Irradiating light that periodically flashes by a strobe light irradiating means to droplets containing uranyl nitrate dropped from a plurality of nozzles, each nozzle according to the dropping state of the liquid droplets irradiated by the strobe light irradiating means An apparatus for producing ammonium deuterated uranate particles, characterized in that the supply amount of a dropping undiluted solution containing uranyl nitrate supplied to the apparatus is adjusted. Irradiate light to the uranyl nitrate-containing droplets falling from each of the nozzles, and adjust the supply amount of the uranyl nitrate-containing dripping stock solution to each nozzle according to the falling state of the irradiated droplets A method for producing ammonium heavy uranate particles.

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