阅读说明：本技术 一种适用于实验室放射性气体处理的净化系统及方法 (Purification system and method suitable for laboratory radioactive gas treatment ) 是由 柳伟平 刘玉昆 郑明杰 周勋 冯宇钦 于 2021-06-10 设计创作，主要内容包括：本发明提供了一种适用于实验室放射性气体处理的净化系统,包括化学反应装置、密封罩、橡胶板、废气净化装置和真空发生器；所述化学反应装置设置在密封罩与橡胶板构成的隔离空间内,并通过橡胶软管、真空发生器将产生的废气传输至废气净化装置；所述废气净化装置的内部装有填料或吸收液,废气经填料或吸收液处理后排至系统外部。本发明还提供了一种基于上述净化系统的气体处理方法。本发明使用密封罩将放射性气溶胶以及有毒有害气体隔绝在很小的空间内,既避免了通风柜箱体内部的放射性污染和腐蚀,又减少了废气的处理量,使得废气净化装置体积较同类发明小很多,在实现实验室废气达标处理的同时,满足废物最小化原则。(The invention provides a purification system suitable for laboratory radioactive gas treatment, which comprises a chemical reaction device, a sealing cover, a rubber plate, a waste gas purification device and a vacuum generator, wherein the chemical reaction device is arranged on the sealing cover; the chemical reaction device is arranged in an isolation space formed by the sealing cover and the rubber plate, and transmits the generated waste gas to the waste gas purification device through the rubber hose and the vacuum generator; the waste gas purification device is internally provided with a filler or an absorption liquid, and waste gas is treated by the filler or the absorption liquid and then discharged to the outside of the system. The invention also provides a gas treatment method based on the purification system. The invention uses the sealing cover to isolate radioactive aerosol and poisonous and harmful gas in a very small space, which not only avoids radioactive pollution and corrosion in the box body of the fume hood, but also reduces the treatment capacity of waste gas, so that the volume of the waste gas purification device is much smaller than that of the similar invention, and the waste minimization principle is satisfied while the standard-reaching treatment of the laboratory waste gas is realized.)

1. A purification system suitable for laboratory radioactive gas treatment is characterized by comprising a chemical reaction device, a sealing cover, a rubber plate, a waste gas purification device and a vacuum generator; the chemical reaction device is arranged in an isolation space formed by the sealing cover and the rubber plate, and transmits the generated waste gas to the waste gas purification device through the rubber hose and the vacuum generator; the waste gas purification device is internally provided with filler or absorption liquid, and the waste gas is treated by the filler or the absorption liquid and discharged to the outside of the system.

2. The decontamination system for laboratory radioactive gas treatment according to claim 1, wherein the rubber plate is located at the bottom end, and the sealing cover is located at the upper end of the rubber plate, and the rubber plate and the sealing cover form a relatively sealed isolated space; the sealing cover is connected with a rubber hose, one end of the rubber hose is located in the sealing cover, and the other end of the rubber hose penetrates through the top of the sealing cover to extend outwards and is connected with the waste gas purification device and the vacuum generator in sequence.

3. The purification system suitable for laboratory radioactive gas treatment according to claim 2, wherein the internal volume of the sealing cover is 3-5 times of the volume of the chemical reaction device, and the sealing cover and the rubber plate form a relative sealed space to completely contain the chemical reaction device; in addition, the top of the sealing cover is provided with an operation hole for operating the chemical reaction device, and the operation hole is opened and closed through a movable plate.

4. The decontamination system for laboratory radioactive gas treatment according to claim 3, wherein the area of said handling hole is not smaller than the projected area of said chemical reaction device.

5. The decontamination system for laboratory radioactive gas treatment according to claim 1, wherein said chemical reaction device is a non-hermetic chemical reaction device; one end of the non-closed chemical reaction device is connected with a power line, and the power line penetrates through the sealing cover and is connected with a power supply outside the purification system.

6. The purification system suitable for laboratory radioactive gas treatment according to claim 1, wherein the exhaust gas purification device is a cylindrical container with an aspect ratio of (3-8): 1; the cylindrical container is filled with a filler for physically adsorbing the waste gas or an absorption liquid for chemically reacting with the waste gas; wherein the liquid level of the absorption liquid is 1/3-2/3 of the height of the cylindrical container.

7. The purification system suitable for laboratory radioactive gas treatment according to claim 6, wherein the filler is silica gel or activated carbon, and the absorption liquid is NaOH solution or deionized water.

8. The purification system suitable for laboratory radioactive gas treatment according to claim 1, wherein the vacuum generator has an adjustable exhaust volume, and the rated exhaust volume is 5 to 10 times of the exhaust gas production volume.

9. The purification system suitable for the treatment of radioactive laboratory gases according to any one of claims 1 to 8, wherein the purification system is installed in a glove box or a fume hood; after the exhaust gas is purified, the exhaust gas is discharged into the glove box or the fume hood and is discharged into the environment through an exhaust pipe of the glove box or the fume hood.

10. A method of gas treatment using a purification system suitable for laboratory radioactive gas treatment according to any one of claims 1 to 9, comprising the steps of:

(1) the glove box or the fume hood exhaust system operates;

(2) placing a chemical reaction device in an isolation space formed by a sealing cover and a rubber plate;

(3) starting a vacuum generator to operate and adjusting the negative pressure in the sealing cover to be-20 to-50 Pa;

(4) opening a movable plate at the top of the sealing cover, adding a reaction reagent into the chemical reaction device, and then closing the movable plate;

(5) starting chemical reaction in the chemical reaction device, and pumping waste gas into a waste gas purification device through a rubber hose under the suction of a vacuum generator; the poisonous and harmful gas in the waste gas is physically absorbed by the filler, or chemically reacts with the absorption liquid; meanwhile, the radioactive aerosol is absorbed on the filler or dissolved in the absorption liquid;

(6) the exhaust gas is purified and then discharged into a glove box or a fume hood, and is discharged into the environment through an exhaust pipe.

Technical Field

The invention relates to the technical field of laboratory waste gas treatment, in particular to a purification system and a purification method suitable for laboratory radioactive gas treatment.

Background

The dispersion of solid or liquid radioactive material particles suspended in air, called radioactive aerosol, is very harmful to the environment and to the physical health of the personnel and therefore must be purified.

The operation of radioactive materials in the radiochemical laboratory is carried out in a fume hood or a closed glove box, and in order to prevent liquid and gas from corroding the inner wall of the box body and facilitate cleaning and decontamination, the inner wall lining of the box body of the fume hood or the glove box for the operation of the radioactive materials is a stainless steel coating. To the radioactive aerosol waste gas of the interior operation production of fume chamber or glove box, according to having or not having poisonous harmful gas in the waste gas, select two kinds of purification schemes: the first scheme is that an exhaust fan, an air pipe and a primary or secondary efficient air particle filter are arranged outside a fume hood or a glove box, radioactive aerosol waste gas is purified and then discharged, and the method is suitable for the condition that the waste gas does not contain toxic and harmful gases; the second scheme is that on the basis of the first scheme, a set of exhaust gas purification system is arranged behind the high-efficiency air particle filter to purify exhaust gas and then discharge the exhaust gas, and the exhaust gas purification system is suitable for the condition that the exhaust gas contains other toxic and harmful gases.

In most cases, the above solution can satisfy the purification requirement of radioactive aerosol waste gas, but in some special cases, such as when the gas generated by radioactive operation has strong corrosivity to stainless steel, the corrosive gas can diffuse into the interior of the box body and the exhaust pipe along with the gas flow, thereby causing serious corrosion to the inner wall of the box body and the exhaust pipe. In addition, the second scheme adopts a mode of treating the toxic and harmful gases by using adsorption (absorption) agents such as activated carbon, a fixed bed with a catalyst, absorption liquid and the like, and because the amount of the waste gas to be treated is large, the using amount of the adsorption (absorption) agents is large, the amount of generated secondary waste is large, and the waste minimization principle is not satisfied.

Chinese patent document CN108231229A discloses a radioactive aerosol purification device and a treatment method thereof, which adopts devices such as a pre-filtering part, an electrocoagulation and collection part, a fan and a terminal filtering and adsorbing part. The device system has more equipment and the method for solving the technical problem is basically the same as the second proposal, namely, when the gas which is highly corrosive to stainless steel exists in the radioactive aerosol waste gas, the corrosion to the equipment cannot be avoided.

Chinese patent document CN106297931B discloses a radioactive aerosol high-efficiency purification and recovery device and a working method thereof, which adopts equipment such as a radioactive aerosol filtering unit, a regulating valve, a vacuum protection valve, an air suction pump, a bubbling unit, etc. The device system has more equipment and the method for solving the technical problem is basically the same as the second scheme, and the corrosion to the equipment cannot be avoided.

Regarding the purification technology of radioactive aerosol, the purification technology of radioactive aerosol at home and abroad is reviewed in an article "purification of radioactive aerosol" published in the publication of "industrial safety and environmental protection" of china in 2009, and the purification method includes filtration, adsorption, washing, retention, decay and the like. In order to achieve the emission of radioactive waste gas reaching the standard, one or more of the technologies are combined in the purification device for radioactive aerosol in industry.

Therefore, the current technical means can basically meet the purification requirements of radioactive aerosol and toxic and harmful gases in waste gas, but the device established by the technologies is generally only suitable for the condition that the toxic and harmful gases do not corrode equipment; for special conditions, if toxic and harmful gases generate strong corrosivity on equipment, the existing technical means does not take targeted measures, and the toxic and harmful gases are mixed with air and other gases to increase waste gas to be treated, so that the problems of equipment corrosion and large waste amount are solved.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a purification system and method suitable for laboratory radioactive gas treatment, which can avoid the problems of equipment corrosion and large waste amount caused by the traditional waste gas treatment system and method.

The invention adopts the following technical scheme to solve the technical problems:

a purification system suitable for laboratory radioactive gas treatment comprises a chemical reaction device, a sealing cover, a rubber plate, a waste gas purification device and a vacuum generator; the chemical reaction device is arranged in an isolation space formed by the sealing cover and the rubber plate, and transmits the generated waste gas to the waste gas purification device through the rubber hose and the vacuum generator; the waste gas purification device is internally provided with filler or absorption liquid, and the waste gas is treated by the filler or the absorption liquid and discharged to the outside of the system.

As one of the preferable modes of the invention, the rubber plate is positioned at the bottom end, the sealing cover is arranged at the upper end of the rubber plate, and the rubber plate and the sealing cover form a relatively sealed isolation space; the sealing cover is connected with a rubber hose, one end of the rubber hose is located in the sealing cover, and the other end of the rubber hose penetrates through the top of the sealing cover to extend outwards and is connected with the waste gas purification device and the vacuum generator in sequence.

As one preferable mode of the invention, the internal volume of the sealing cover is 3-5 times of the volume of the chemical reaction device, and the relative sealing space formed by the sealing cover and the rubber plate completely contains the chemical reaction device; in addition, the top of the sealing cover is provided with an operation hole for operating the chemical reaction device, and the operation hole is opened and closed through a movable plate.

In a preferred embodiment of the present invention, the area of the operation hole is not smaller than the projected area of the chemical reaction device.

In a preferred embodiment of the present invention, the chemical reaction apparatus is a non-closed chemical reaction apparatus; one end of the non-closed chemical reaction device is connected with a power line, and the power line penetrates through the sealing cover and is connected with a power supply outside the purification system.

In a preferred embodiment of the present invention, the exhaust gas purification apparatus is a cylindrical container having an aspect ratio of (3-8): 1; the cylindrical container is filled with a filler for physically adsorbing the waste gas or an absorption liquid for chemically reacting with the waste gas; wherein the liquid level of the absorption liquid is 1/3-2/3 of the height of the cylindrical container.

As one preferable mode of the present invention, the filler is specifically silica gel or activated carbon, and the absorption liquid is NaOH solution or deionized water.

In a preferred embodiment of the present invention, the vacuum generator has an adjustable exhaust volume, and the rated exhaust volume is 5 to 10 times the amount of exhaust gas generated.

In a preferred embodiment of the present invention, the purification system is installed in a glove box or a fume hood; after the exhaust gas is purified, the exhaust gas is discharged into the glove box or the fume hood and is discharged into the environment through an exhaust pipe of the glove box or the fume hood.

A method for gas treatment based on the purification system suitable for laboratory radioactive gas treatment comprises the following steps:

(1) the glove box or the fume hood exhaust system operates;

(2) placing a chemical reaction device in an isolation space formed by a sealing cover and a rubber plate;

(3) starting a vacuum generator to operate and adjusting the negative pressure in the sealing cover to be-20 to-50 Pa;

(4) opening a movable plate at the top of the sealing cover, adding a reaction reagent into the chemical reaction device, and then closing the movable plate;

(5) starting chemical reaction in the chemical reaction device, and pumping waste gas into a waste gas purification device through a rubber hose under the suction of a vacuum generator; the poisonous and harmful gas in the waste gas is physically absorbed by the filler, or chemically reacts with the absorption liquid; meanwhile, the radioactive aerosol is absorbed on the filler or dissolved in the absorption liquid;

(6) the exhaust gas is purified and then discharged into a glove box or a fume hood, and is discharged into the environment through an exhaust pipe.

Compared with the prior art, the invention has the advantages that:

(1) the invention uses the sealed cover to isolate the waste gas containing radioactive aerosol and corrosive toxic harmful gas generated in the fume hood or closed glove box in a very small space, and adopts the washing technology to purify the corrosive toxic harmful gas firstly, thereby not only avoiding the corrosion in the glove box or the fume hood box body, but also greatly reducing the treatment amount of the waste gas, leading the volume of the waste gas purification device to be much smaller than that of the similar invention, meeting the waste minimization principle while realizing the standard treatment of the laboratory waste gas, and achieving the aim of protecting the environment and the public health;

(2) the device has simple structure, is light and flexible, is arranged in the box body of the fume hood, and can be used for manufacturing a device meeting the laboratory waste gas emission requirement according to the actual condition;

(3) the device adopts the vacuum generator to pump and exhaust waste gas, does not need rotating parts, does not need maintenance, and has the advantages of convenient and reliable operation, low cost and easy installation and disassembly.

Drawings

Fig. 1 is a schematic view of a purification system suitable for laboratory radioactive gas treatment in example 1 (the arrows in fig. 1 indicate the direction of exhaust gas transport).

In the figure: 1 is a non-closed chemical reaction device, 11 is a power line, 2 is a sealing cover, 3 is a chloroprene rubber plate, 4 is a waste gas purification device, 41 is a cylindrical absorption column, 42 is absorption liquid, 5 is a vacuum generator, 6 is a rubber hose, and 7 is a glove box or a fume hood.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.

The design idea is as follows: the waste gas containing corrosiveness is limited in the isolated space and purified firstly, so that the corrosion of equipment is prevented, and simultaneously, the volume of the waste gas to be purified is reduced as much as possible, thereby achieving the purposes of miniaturization of the waste gas purification system and waste minimization.

Example 1

As shown in fig. 1, a purification system suitable for laboratory radioactive gas treatment according to the present embodiment is installed in a glove box or a fume hood 7. The purification system comprises a non-closed chemical reaction device 1, a sealing cover 2, a chloroprene rubber plate 3, a waste gas purification device 4, a vacuum generator 5 and a rubber hose 6; wherein, the non-closed chemical reaction device 1 is arranged in an isolated space formed by the sealing cover 2 and the chloroprene rubber plate 3, and transmits the generated waste gas to the waste gas purification device 4 through the rubber hose 6 and the vacuum generator 5; the exhaust gas purification apparatus 4 contains an absorption liquid 42 therein, and the exhaust gas is treated by the absorption liquid 42 and discharged into the glove box or the fume hood 7, and is discharged into the environment through the exhaust pipe of the glove box or the fume hood 7.

Further, in the present embodiment, the neoprene sheet 3 is located at the bottom end, and the sealing cover 2 covers the neoprene sheet 3 at the upper end, and the two form a relatively sealed isolation space. The top of the sealing cover 2 is connected with a rubber hose 6, one end of the rubber hose 6 is positioned in the sealing cover 2, and the other end of the rubber hose passes through a sleeve at the top of the sealing cover 2 to extend outwards and is sequentially connected with connecting pipes at two ends of the waste gas purification device 4 and the vacuum generator 5.

Further, in the present embodiment, the non-sealed chemical reaction apparatus 1 is a plating tank which functions to supply radionuclides in a solution by a plating method⁶³Ni is deposited on the copper plate to form a metal film, and chlorine is generated in the electroplating process. The size of the plating bath L × W × H is 100 × 30 × 70mm, and the maximum outer size L × W × H after the cathode and the anode are inserted is 100 × 30 × 100 mm. One end of the electroplating pool is connected with a power cord 11, and the power cord 11 passes through the sealing cover 2 and is connected with a power supply outside the system.

Further, in the present embodiment, the sealing cap 2 and the neoprene rubber sheet 3 need to be manufactured according to the largest external dimensions of the plating bath and the accessories, so as to completely contain the plating bath in a small isolation space which is relatively sealed. Meanwhile, the top of the sealing cover 2 is provided with an operation hole for operating the non-closed chemical reaction device 1, and the operation hole is opened and closed through a movable plate; the area of the operation hole is not smaller than the projected area of the non-hermetic chemical reaction apparatus 1.

Specifically, the sealing cover 2 is a rectangular box without a lower cover plate, two plexiglass plates with a thickness of L × W × δ of 200 × 160 × 3mm and a thickness of L × W × δ of 160 × 160 × 3mm are spliced into a rectangular box without an upper cover plate and a lower cover plate, and four plates are spliced into a rectangular box without an upper cover plate and a lower cover plateThe joint end is a 45-degree inclined plane, the joint is firmly bonded and sealed by epoxy resin, and the bottom end surface is ensured to be smooth and on the same plane; then, the top cover plate is spliced by two plexiglas plates of 220 × 90 × 3mm, one of the two plates occupies half of the top cover plate of the rectangular box and is fixed by bonding with epoxy resin, and two plates are opened in the middle of the platesThe other is a movable plate, and the butt joint surfaces of the two plates are flat and smooth. When the chloroprene rubber sheet 3 is used, the sealing cap 2 is placed on the chloroprene rubber sheet 3 with its bottom end facing downward, and the bottom end face of the sealing cap is brought into close contact with the chloroprene rubber sheet 3 to form a sealing face.

Further, in the present embodiment, the exhaust gas purifying device 4 is a cylindrical absorption column 41 having a column diameter Connecting pipe with column height of 300mm and two ends of columnThe length is 40mm, the random pile D multiplied by H in the column is 8 multiplied by 8mm plastic raschig ring to 90mm, the cylindrical absorption column 41 is vertically placed and fixed reliably. Specifically, 2mol/l NaOH solution (namely the absorption liquid 42) which reacts with the waste gas is filled in the cylindrical absorption column 41, and the liquid level of the NaOH solution is 1/3-2/3 of the height of the cylindrical container.

Further, in the embodiment, the exhaust volume of the vacuum generator 5 is adjustable from 0L/min to 27L/min, and the connecting pipe is usedThe rated displacement is 5-10 times of the waste gas production.

In addition, it should be noted that, in the present embodiment, the rubber hose 6 is made of the specificationBesides, sleeves are arranged at the joints of the rubber hoses 6 and the sealing cover 2, and sleeves are respectively arranged at the joints of the power lines 11 and the sealing cover 2, the joints of the power lines 11 and the glove box or the box body of the fume hood 7, and the joints of the rubber hoses 6 and the glove box or the box body of the fume hood 7.

The method for treating the radioactive aerosol waste gas generated in the electroplating process by using the purification system comprises the following steps:

(1) an exhaust system of the glove box or the fume hood 7 runs;

(2) placing the electroplating bath in an isolation space formed by the sealing cover 2 and the chloroprene rubber plate 3;

(3) starting the vacuum generator 5 to operate, adjusting the air pressure flow entering the vacuum generator 5, and controlling the negative pressure in the sealing cover 2 to be-20 to-50 Pa;

(4) opening a movable plate at the top of the sealing cover 2, adding electroplating solution into the electroplating bath, inserting a cathode (copper plate) and an anode, fixing, and then closing the movable plate;

(5) electrifying the electroplating bath, and starting the electrochemical reaction; at the moment, chlorine generated by the anode carries radioactive aerosol to be mixed with a small amount of air leaked into the sealing cover 2, and the mixture enters the waste gas purification device 4 through the rubber hose 6 under the negative pressure suction; chlorine in the waste gas and NaOH solution are subjected to chemical reaction, the radioactive aerosol is dissolved in the NaOH solution, and the waste gas is purified accordingly;

(6) filtering the purified waste gas for 1 hour by sampling filter paper, and measuring the radioactivity of the surface of the sampling filter paper to be a background level by using a beta surface pollution monitor; no discoloration was detected with pH paper. The above test results show that the exhaust gas after purification meets the environmental emission requirements.

Example 2

The structure of the purification system suitable for the treatment of radioactive gas in a laboratory according to this embodiment is substantially the same as that of embodiment 1, and the main differences are that: (1) in this example, the unsealed chemical reaction apparatus 1 was a beaker having a volume of 100mL and a specification D × H of 52 × 72mm, and the nickel-plated copper plate was dissolved with ammonium trichloroacetate, and ammonia gas and radioactive aerosol were emitted during the dissolution of the copper plate. (2) In this embodiment, the cylindrical absorption column 41 of the exhaust gas purification apparatus 4 is filled with a filler, not the absorption liquid 42; when the waste gas passes through, the waste gas is treated by the filler and then is discharged into the glove box or the fume hood 7, and the waste gas is discharged into the environment through an exhaust pipe of the glove box or the fume hood 7; specifically, the filler is silica gel or activated carbon which physically adsorbs the exhaust gas. The equipment and procedures used in example 1 are fully applicable to example 2.

Filtering the purified waste gas for 1 hour by sampling filter paper, and measuring the radioactivity of the surface of the sampling filter paper to be a background level by using a beta surface pollution monitor; no discoloration was detected with pH paper. The above test results show that the exhaust gas after purification meets the environmental emission requirements.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.