阅读说明：本技术 一种放射性废树脂芬顿氧化废液干燥减容处理装置及方法 (Drying and volume reduction treatment device and method for radioactive waste resin Fenton oxidation waste liquid ) 是由 柳兆峰 闫晓俊 郭喜良 高超 安鸿翔 崔安熙 柳兆滨 冯文东 刘建琴 薛海龙 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种放射性废树脂芬顿氧化废液干燥减容处理装置及方法,所述装置包括废液输送计量单元、干燥单元、尾气处理单元；所述废液输送计量单元包括废液暂存罐、输送泵、定体积计量罐；所述干燥单元包括电加热器、干燥桶、密封顶盖、温度传感器、温控器、压力传感器。本发明所提供的放射性废树脂芬顿氧化废液干燥减容处理装置及方法可以将废树脂芬顿氧化过程中产生的放射性废物最少化,减少后续的处理成本。(The invention discloses a drying and volume-reducing treatment device and method for radioactive waste resin Fenton oxidation waste liquid, wherein the device comprises a waste liquid conveying and metering unit, a drying unit and a tail gas treatment unit; the waste liquid conveying and metering unit comprises a waste liquid temporary storage tank, a conveying pump and a fixed-volume metering tank; the drying unit comprises an electric heater, a drying barrel, a sealing top cover, a temperature sensor, a temperature controller and a pressure sensor. The device and the method for drying and volume-reducing the waste liquid generated by the Fenton oxidation of the radioactive waste resin can minimize the radioactive waste generated in the Fenton oxidation process of the waste resin and reduce the subsequent treatment cost.)

1. A drying and volume-reducing treatment device for radioactive waste resin Fenton oxidation waste liquid is characterized by comprising a waste liquid conveying and metering unit, a drying unit and a tail gas treatment unit;

the waste liquid conveying and metering unit comprises a waste liquid temporary storage tank, a conveying pump and a fixed-volume metering tank; the radioactive waste resin Fenton oxidation waste liquid is stored in a waste liquid temporary storage tank, and the delivery pump is used for pumping the waste liquid into a constant-volume metering tank;

the drying unit comprises an electric heater, a drying barrel, a sealing top cover, a temperature sensor, a temperature controller and a pressure sensor; the drying barrel is communicated with the fixed-volume metering tank through a pipeline, and an electric valve is arranged on the pipeline;

the tail gas treatment unit comprises a condenser, a condensate collecting tank and a non-condensable gas filter; and tail gas generated by the drying unit enters a condenser, condensate is collected in a condensate collecting tank, and non-condensable gas enters a non-condensable gas filter for treatment.

2. A drying and volume-reducing treatment device for radioactive waste resin fenton oxidation waste liquid according to claim 1, wherein an overflow return pipe is further provided between the volumetric metering tank and the waste liquid temporary storage tank.

3. A drying and volume-reducing treatment apparatus for radioactive waste resin fenton oxidation waste liquid according to claim 1, wherein the volume of the constant volume metering tank is 5L.

4. A drying and volume-reducing treatment device for radioactive waste resin fenton oxidation waste liquid according to claim 1, wherein the electric heater is tile-shaped and is enclosed outside the drying barrel; the number of the electric heaters is two.

5. A drying and volume-reducing treatment device for radioactive waste resin Fenton oxidation waste liquid according to claim 1 or 4, wherein the electric heater is a silicon carbide infrared heater with power of 8 kW.

6. A drying and volume-reducing treatment device for radioactive waste resin Fenton oxidation waste liquid according to claim 1, wherein the drying barrel is a 50L stainless steel barrel.

7. A radioactive spent resin fenton oxidation waste liquid drying volume reduction treatment apparatus according to claim 1, wherein the pressure sensor is disposed on a drum sealing top cover.

8. A drying and volume-reducing treatment apparatus for radioactive spent resin Fenton oxidation waste liquid according to claim 1, wherein the temperature sensor is arranged in a gap between the outside of the drying barrel and the electric heater, and the temperature controller controls the electric heater to operate at a constant temperature.

9. A method for drying and volume-reducing radioactive waste resin fenton oxidation waste liquid by using the device of claim 2, wherein the method comprises the following steps:

step (1), conveying the radioactive waste resin Fenton oxidation waste liquid stored in the waste liquid temporary storage tank into a constant-volume metering tank by using a conveying pump until the upper part of the side of the constant-volume metering tank overflows, and allowing the overflowing waste liquid to flow into the waste liquid temporary storage tank through an overflow return pipeline;

step (2), opening an electric valve below the constant-volume metering tank to feed materials into the drying barrel according to the requirement of the drying process;

step (3), controlling an electric heater by using a temperature controller to heat and dry the waste liquid conveyed into the drying barrel, vaporizing and discharging water in the waste liquid, and finally forming a compact solid salt block in the barrel; in the drying process, monitoring the pressure in the barrel by using a pressure sensor;

and (4) condensing the tail gas discharged in the waste liquid drying process by using a tail gas treatment unit to recover moisture, collecting the condensate into a condensate collecting tank, and directly and safely discharging the non-condensable gas after filtering.

10. A method for drying and volume-reducing radioactive spent resin fenton oxidation waste liquid according to claim 9, wherein the salt cake formed by drying in step (3) is finally fixed together with the drying barrel.

Technical Field

The invention relates to the technical field of radioactive waste volume reduction treatment, in particular to a device and a method for drying and volume reduction treatment of radioactive waste resin Fenton oxidation waste liquid.

Background

The radioactive waste resin containing organic substances is one of the difficulties in the management of radioactive waste in China at present. At present, most of radioactive waste resin generated by nuclear military units is in a temporary storage state, and most of radioactive waste resin generated by nuclear power plants is treated by adopting a traditional cement curing process. The solidification of the waste resin cement has the advantages of simple process, mature technology, low treatment cost and the like, but has the technical bottlenecks of waste capacity increase and long-term stability of a solidified body.

At present, the inorganic volume reduction treatment technology of radioactive waste resin is a domestic research hotspot, and the core technology comprises steam reforming, supercritical water oxidation, Fenton oxidation and the like. The Fenton oxidation of the radioactive waste resin is to carry out efficient oxidative decomposition on organic resin particles under acidic conditions, and radioactive nuclides contained in the radioactive waste resin and generated substances are left in waste liquid.

The treatment of the radioactive waste resin oxidation waste liquid has two technical schemes: firstly, cement solidification treatment; secondly, deep purification treatment. The international common method is that the radioactive waste resin oxidation waste liquid is processed by cement solidification after evaporation and concentration. The cement solidification treatment has the advantages of mature process and low treatment cost, and the waste liquid cement can directly meet the final treatment requirement after being solidified; but the defects are that the oxidation waste liquid needs to use a large amount of chemical reagents for pH modulation before solidification, and the waste liquid after modulation needs to be evaporated and concentrated for a long time and then is solidified by cement.

The deep purification is to separate the radioactive nuclide from the waste liquid, and the radioactive nuclide is absorbed into a small amount of solid medium or reduced into a stable state, and the method can make up the defects of the traditional direct cement solidification. The conventional technical routes for deeply purifying the radioactive waste liquid comprise two routes: firstly, the membrane treatment process has the defects that the high selectivity of the membrane is closely related to the characteristics of waste liquid, pretreatment such as filtration, ion exchange, microfiltration, even ultrafiltration and the like is required before membrane treatment, the process links are more, and the amount of secondary waste is large. And secondly, ion exchange and adsorption, the method needs to select and use an adsorbent with high adsorption performance aiming at different nuclides, and the used adsorbent needs to be cured. After the accident of the Japanese Fudao, a large amount of molecular sieves are adopted to adsorb and separate Cs-137 and Sr-90 in radioactive wastewater generated by the accident.

Considering that the aim of the radioactive waste resin inorganic treatment is waste minimization and simultaneously combines the characteristics of waste resin oxidation waste liquid, the invention provides a drying and volume reduction treatment device for radioactive waste resin Fenton oxidation waste liquid, so as to achieve the aim of radioactive waste minimization.

Disclosure of Invention

In view of the defects in the prior art, the present invention provides a drying and volume-reducing treatment apparatus and method for a waste radioactive waste resin fenton oxidation liquid, so as to minimize the waste generated in the fenton oxidation process of the waste radioactive resin.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a drying and volume-reducing treatment device for radioactive waste resin Fenton oxidation waste liquid comprises a waste liquid conveying and metering unit, a drying unit and a tail gas treatment unit;

the waste liquid conveying and metering unit comprises a waste liquid temporary storage tank, a conveying pump and a fixed-volume metering tank; the radioactive waste resin Fenton oxidation waste liquid is stored in a waste liquid temporary storage tank, and the delivery pump is used for pumping the waste liquid into a constant-volume metering tank;

the drying unit comprises an electric heater, a drying barrel, a sealing top cover, a temperature sensor, a temperature controller and a pressure sensor; the drying barrel is communicated with the fixed-volume metering tank through a pipeline, and an electric valve is arranged on the pipeline;

the tail gas treatment unit comprises a condenser, a condensate collecting tank and a non-condensable gas filter; and tail gas generated by the drying unit enters a condenser, condensate is collected in a condensate collecting tank, and non-condensable gas enters a non-condensable gas filter for treatment.

Further, an overflow return pipeline is further arranged between the fixed-volume metering tank and the waste liquid temporary storage tank.

Further, the volumetric metering tank has a volume of 5L.

Further, the electric heater is tile-shaped and is enclosed outside the drying barrel; the number of the electric heaters is two.

Further, the electric heater is a silicon carbide infrared heater, and the power is 8 kW.

Further, the drying barrel is a 50L stainless steel barrel.

Further, the pressure sensor is arranged on the drum sealing top cover.

Further, the temperature sensor is disposed at a gap between an outside of the drying tub and the electric heater.

Further, the temperature controller controls the electric heater to run at a constant temperature.

The invention also provides a drying and volume reduction treatment method for the radioactive waste resin Fenton oxidation waste liquid by using the device, which comprises the following steps:

step (1), conveying the radioactive waste resin Fenton oxidation waste liquid stored in the waste liquid temporary storage tank into a constant-volume metering tank by using a conveying pump until the upper part of the side of the constant-volume metering tank overflows, and allowing the overflowing waste liquid to flow into the waste liquid temporary storage tank through an overflow return pipeline;

step (2), opening an electric valve below the constant-volume metering tank to feed materials into the drying barrel according to the requirement of the drying process;

step (3), controlling an electric heater by using a temperature controller to heat and dry the waste liquid conveyed into the drying barrel, vaporizing and discharging water in the waste liquid, and finally forming a compact solid salt block in the barrel; in the drying process, monitoring the pressure in the barrel by using a pressure sensor;

and (4) condensing the tail gas discharged in the waste liquid drying process by using a tail gas treatment unit to recover moisture, collecting the condensate into a condensate collecting tank, and directly and safely discharging the non-condensable gas after filtering.

Further, the salt cake formed by drying in the step (3) is finally subjected to a fixing treatment together with the drying tub.

The invention has the beneficial effects that:

1) according to the device and the method for drying and volume-reducing the radioactive waste resin Fenton oxidation waste liquid, provided by the invention, aiming at the characteristics of low pH value and low salt content of the resin oxidation waste liquid, the waste liquid is heated and dried after being modulated to form compact salt blocks, so that the volume of the radioactive waste to be finally treated is reduced.

2) The device and the method for drying and volume-reducing the radioactive waste resin Fenton oxidation waste liquid provided by the invention are used for heating and drying the waste liquid in a closed system, and the intermittent feeding is completed through a volume-fixed metering tank, so that the continuous drying of the waste liquid is realized.

3) The device and the method for drying and volume-reducing the radioactive waste resin Fenton oxidation waste liquid provided by the invention are not influenced by the type and source of the waste resin, and can realize volume-reducing treatment on various waste resin Fenton oxidation waste liquids.

4) The device and the method for drying and volume-reducing the radioactive waste resin Fenton oxidation waste liquid provided by the invention can realize waste volume reduction while realizing waste liquid stabilization treatment, and the volume reduction coefficient is about 30.

Drawings

FIG. 1 is a schematic structural diagram of a drying and volume-reducing treatment apparatus for waste radioactive resin Fenton oxidation waste liquid according to the present invention;

wherein: 1-a waste liquid temporary storage tank; 2-a delivery pump; 3-a volumetric metering tank; 4-an overflow return line; 5, electrically operated valve; 6-sealing the top cover; 7-drying the barrel; 8-electric heating; 9-a temperature sensor; 10-a temperature controller; 11-a tail gas treatment unit; 12-pressure sensor.

Detailed Description

The invention is described in further detail below with reference to the drawings and the detailed description.

As shown in FIG. 1, the device for drying and volume reduction of radioactive waste resin Fenton oxidation waste liquid comprises a waste liquid conveying and metering unit, a drying unit and a tail gas treatment unit 11.

The waste liquid conveying and metering unit comprises a waste liquid temporary storage tank 1, a conveying pump 2 and a fixed-volume metering tank 3; the radioactive waste resin Fenton oxidation waste liquid is stored in a waste liquid temporary storage tank 1, and the delivery pump 2 is used for pumping the waste liquid into a fixed-volume metering tank 3; an overflow return pipeline 4 is also arranged between the fixed-volume metering tank and the waste liquid temporary storage tank; the volume of the volumetric metering tank 3 is 5L.

The drying unit comprises an electric heater 8, a drying barrel 7, a sealing top cover 6, a temperature sensor 9, a temperature controller 10 and a pressure sensor 12. The drying barrel is communicated with the fixed-volume metering tank through a pipeline, and an electric valve 5 is arranged on the pipeline; the waste resin oxidation waste liquid stored in the temporary storage tank is conveyed into the metering tank 3 by the conveying pump until the upper part of the side of the metering tank 3 overflows, and the waste liquid flows back to the waste liquid temporary storage tank 1 through the overflow return pipeline 4. According to the requirement of the drying process, the electric valve 5 below the metering tank 3 is opened to feed materials into the drying barrel.

The electric heater 8 is of a tile shape and is surrounded outside the drying barrel 7; the drying barrel 7 is a 50L stainless steel barrel. The electric heater 8 is a silicon carbide infrared heater, the power is 8kW, the power supply is 220VAC/50Hz, and a hollow column shape is formed in the middle of the folded two pieces. The drying tub 7 is placed therein, heated from the side wall, and dries the waste liquid. The temperature sensor 9 is disposed in a gap between the outside of the drying tub 7 and the electric heater 8, and monitors the operating temperature of the electric heater 8. The temperature controller 10 controls the electric heater to operate at a constant temperature. The pressure sensor 12 is arranged on the sealing top cover 6 and used for monitoring the pressure in the drying process barrel. The drying unit is mainly used for heating and drying the waste liquid conveyed into the drying barrel, vaporizing and discharging moisture in the waste liquid, finally forming compact solid salt blocks in the barrel, and carrying out fixing treatment together with the drying barrel 7.

The tail gas treatment unit comprises a condenser, a condensate collecting tank and a non-condensable gas filter; the condenser adopts cold water as a refrigerant, tail gas generated by the drying unit enters the condenser, condensate is collected in the condensate collecting tank, and non-condensable gas enters the non-condensable gas filter for treatment and then is directly and safely discharged.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.