CN109939520B - A kind of supercritical fluid particle removal device and supercritical fluid purification method - Google Patents

Abstract

The invention discloses a supercritical fluid particle removing device and a supercritical fluid purification method, wherein the removing device comprises a filtering pipe section for filtering particles and a deposition pipe section which is connected with the filtering pipe section and enables the particles to be deposited, the supercritical fluid filters part of particle impurities through a filtering membrane of the filtering pipe section, and then the particle impurities are deposited under the actions of a re-expansion and contraction effect, a thermophoresis effect and the like of the deposition pipe section, so that the particles in the supercritical fluid are removed, and the supercritical fluid is purified. The invention strongly removes the particles in the supercritical fluid through various comprehensive actions, has high removal efficiency and good removal effect, improves the operation efficiency and safety of equipment, improves the purity of the fluid, prolongs the service life of the equipment, can remove radioactive and non-radioactive particles with the particle size of less than 2.5 mu m, and can be used as a special purification device for the radioactive supercritical fluid in the field of nuclear power and energy power to effectively purify the radioactive and non-radioactive supercritical fluid.

Description

A kind of supercritical fluid particle removal device and supercritical fluid purification method

technical field

The invention belongs to the fields of energy and mechanical equipment, relates to the purification of supercritical fluids in the field of nuclear energy, energy power and other fields, in particular to a supercritical fluid particle removal device and a supercritical fluid purification method.

Background technique

Dust purifier products are common products in production and life, with a wide variety of applications, and play a vital role in production and life. It is of great significance to residents' health and environmental protection, from small to anti-smog masks, drinking water purification to the purification of factory emissions. Therefore, it is of great significance to develop dedusting and purification equipment suitable for various fields, especially the purification equipment for supercritical fluid in the field of nuclear energy.

In the field of nuclear energy, supercritical carbon dioxide is used as the working fluid for the fourth-generation high-temperature gas-cooled reactor. It is inevitable that the working fluid will be mixed with fine radioactive particulate matter. The existence of particulate matter will affect the heat transfer performance of the working fluid, affect the service life of the pipeline, and may even affect the The safe operation of the reactor will even threaten the life and health of the workers around the nuclear power plant. Therefore, it is particularly important to remove the fine particles in the supercritical carbon dioxide working medium.

At present, the particle removers on the market include electrostatic precipitators, cyclone dust collectors, bag filters, etc., all of which do not take into account the high temperature characteristics of supercritical fluids, and most of them use a single principle for dust removal. However, the dust removal effect on fine particles (diameter less than 2.5μm) is poor. Existing dust removal inventions for supercritical working fluids, such as a particle remover using supercritical carbon dioxide as a working fluid and a supercritical system passive particle removal device, do not consider the radioactive characteristics of supercritical fluids to select radiation protection The material will cause radiation to the operator when the remover is working, which will affect the health of the personnel. In addition, the removal effect of particles with a particle size of 2.5 μm or less is not ideal.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned problems, the inventors have carried out keen research and designed a supercritical fluid particle removal device and a supercritical fluid purification method. It can realize the removal of radioactive or non-radioactive particles, and collect and remove particles through the collection box. The removal device has a simple structure, high removal efficiency and good removal effect, thereby improving the operation efficiency, safety, and fluidity of the equipment. Purity and extended equipment life.

One aspect of the object of the present invention is to provide a supercritical fluid particle removal device, the device includes a filter pipe section for filtering particles and a deposition pipe section connected to the filter pipe section and allowing particles to be deposited.

The second aspect of the object of the present invention is to provide the use of the device according to the first aspect of the present invention for removing particles with a particle size of 0.1-10 μm in a supercritical fluid.

The third aspect of the object of the present invention is to provide a method for purifying supercritical fluid using the removal device described in the first aspect of the present invention, the method comprising the following steps:

Step 1, install the supercritical fluid fine particulate matter removal device in the supercritical fluid pipeline;

Step 2, carry out cooling water circulation, and then the supercritical fluid enters the transition pipe section and the deposition pipe section (9) to remove particulate matter;

Step 3, removal ends, closes supercritical fluid inlet valve (6) and supercritical fluid pump (1);

Step 4, cleaning the inner wall of the thermophoresis removal tube (11);

Step 5. After cleaning, the particles are collected into the particle collection box (15).

The beneficial effects that the present invention has are:

(1) The removing device of the present invention produces strong force through nanofiltration, expansion and contraction effect, thermophoresis effect, optionally also including the comprehensive influence of centrifugal force and turbulent flow, and removes the particles in the supercritical fluid forcefully to the filter membrane It has a good removal effect on the wall of the tube and the thermophoresis removal, so as to ensure the safe and stable operation of the equipment, improve the efficiency and the service life of the equipment;

(2) the deposition tube section in the removal device of the present invention adopts a honeycomb structure, which increases the contact area between the supercritical fluid and the low temperature tube wall, improves the thermophoretic deposition efficiency, and then improves the particle removal effect;

(3) The removal device of the present invention provides a method for collecting particles, using compressed air, optionally with the combined effect of the thermophoresis effect, to clean and remove the particles on the wall of the thermophoresis removal tube, and use a collection box to collect and clean particles, improving the removal efficiency;

(4) The removal device of the present invention has the advantages of simple structure, good removal effect, simple and efficient removal method, and can remove radioactive and non-radioactive particles with a particle size of less than 2.5 μm, thereby improving the operation efficiency, safety, fluidity and the purity of the equipment and prolong the service life of the equipment;

(5) The present invention provides a method for purifying supercritical fluid by adopting the removal device, filtering and removing some fine particles impurities through a filter membrane, and then depositing the fine particles through the deposition pipe section, which significantly improves the removal efficiency;

(6) The removal device of the present invention can be used as a purification device for radioactive supercritical fluids in the fields of nuclear power and energy power, and can effectively purify radioactive and non-radioactive supercritical fluids.

Description of drawings

1 shows a schematic diagram of a supercritical fluid particle removal device according to a preferred embodiment of the present invention;

FIG. 2 shows a top view of a thermophoresis removal tube according to a preferred embodiment of the present invention.

Description of reference numbers:

1- supercritical fluid pump;

2- Filter pipe section valve;

3-seal screw;

4- sealing gasket;

5- filter membrane;

6- supercritical fluid inlet valve;

7- Compressed air inlet valve;

8- compressed air pump;

9-deposition pipe section I;

10- Cooling water outlet valve;

11- thermal electrophoresis removal tube;

12- cooling water channel;

13- cooling water pump;

14-Cooling water inlet valve;

15 - Particle collection box;

16-Particle outlet valve;

17 - Supercritical fluid outlet valve.

Detailed ways

The present invention will be further described in detail below through the accompanying drawings and preferred embodiments. The features and advantages of the present invention will become more apparent from these descriptions.

Supercritical Fluid Reactor (SCWR) is the only one of the six fourth-generation nuclear reactors that uses light water as a coolant. It is an innovative design developed on the basis of existing water-cooled reactor technology and supercritical thermal power technology. Compared with the water-cooled reactor, it has the characteristics of simple system, small device size, high thermal efficiency, better economy and safety.

The inventors found that during the operation of the supercritical fluid reactor, the supercritical fluid is a high temperature and high pressure fluid. During the operation of the equipment, the internal components, fuel rods and other components of the supercritical fluid reactor will generate numerous fine particles. The pipeline produces fluid accelerated corrosion, chemical corrosion, physical wear, abrasive corrosion, etc. The interweaving of these effects will have a serious impact on the life of the pipeline, and may destroy the integrity of the primary circuit, resulting in the supercritical fluid cannot run safely and stably in the pipeline. . Therefore, it is extremely important to remove fine particle impurities in supercritical fluids.

According to the present invention, the present invention provides a supercritical fluid particle removal device, which comprises a filter pipe section for filtering particles and a deposition pipe section 9 connected with the filter pipe section and capable of depositing particles.

In the present invention, the removing device can remove particulate impurities with a particle size of less than 2.5 μm in the radioactive or non-radioactive supercritical fluid.

According to the present invention, the supercritical fluid particle removal device is installed in the supercritical fluid pipeline, and the supercritical fluid flows into the device from top to bottom, that is, the supercritical fluid flows in the direction of gravity.

According to the present invention, a supercritical fluid pump 1 and a filter pipe section valve 2 are provided at the inlet of the device, and the supercritical fluid enters the filter pipe section through the supercritical fluid pump 1 and the filter pipe section valve 2 .

According to the present invention, the filter tube section is provided with a filter membrane 5. The supercritical fluid enters the filter tube section and is first filtered by the filter membrane 5 to remove some particulate impurities. The pore size of the filter membrane 5 is selected according to the actual situation. A nanofiltration membrane for filtering particles with a particle size of 0.1 to 10 μm, more preferably, the filter membrane 5 is a nanofiltration membrane capable of filtering particles with a particle size of 0.1 to 2.5 μm.

According to the present invention, the flow direction of the supercritical fluid is perpendicular to the filter membrane 5 , and the filter membrane 5 is fixed to the filter tube section through the sealing gasket 4 and the sealing screw 3 .

In the present invention, when the particles deposited on the filter membrane 5 are saturated, the filter membrane 5 needs to be replaced or cleaned, preferably the filter membrane 5 is replaced or cleaned regularly to ensure the filtering effect.

According to the present invention, the filter pipe section is detachable, and is used for regularly replacing or cleaning the filter membrane 5 to ensure the filtering effect.

According to the present invention, the filter pipe section is provided with 1 to multiple filter membranes 5, preferably 1 to 3 filter membranes 5, which can achieve better filtering effect. The number of filtration membranes 5 is too large, which hinders the supercritical fluid greatly, and requires the supercritical fluid pump 1 to provide greater pressure to perform better filtration.

In the present invention, the supercritical fluid enters the filter pipe section through the supercritical fluid inlet valve between the filter pipe section, the filter pipe section and the deposition pipe section 9 .

According to the present invention, the deposition tube section 9 includes a supercritical fluid channel for the circulation of the supercritical fluid, the supercritical fluid channel includes a thermophoretic removal tube 11, and the supercritical fluid enters the thermophoretic removal tube 11 of the supercritical fluid channel. The electrophoresis effect removes particles from supercritical fluids.

According to the present invention, there are several thermophoresis removal tubes 11 , preferably 5 to 15, more preferably 9 to 12.

According to the present invention, the inner diameter of the deposition pipe section 9 is 8-32 cm, preferably 10-30 cm.

According to the present invention, the inner diameter of the thermophoretic removal tube 11 is 1 to 6 cm, preferably 1 to 5 cm, the length of the thermophoretic removal tube 11 is equal to the deposition length of the deposition tube section 9, and the deposition length of the deposition tube section 9 is 0.3 to 5 cm. 1.5m, preferably 0.5 to 1.2m.

According to the present invention, the two ends of several thermophoresis removal tubes 11 are connected, preferably through connecting plates.

The inventors found that when the supercritical fluid enters the deposition tube section 9 and then splits into a plurality of thermophoretic removal tubes 11, the expansion and contraction effect is caused by the sudden change of the flow cross section of the supercritical fluid. Under the expansion and contraction effect, the supercritical fluid and the The particle impurities therein undergo friction and relative motion, so that the particles in the supercritical fluid are removed to the inner wall of the thermophoresis removal tube 11 to realize the removal of the particles.

According to the present invention, in the deposition pipe section 9, the supercritical fluid channel is removed, and the remaining space is the cooling water channel 12, the cooling water channel 12 and the cooling water inlet end provided with the cooling water inlet valve 14 and the cooling water outlet valve 10. The cooling water outlet ends are communicated to form a cooling water circulation system.

According to the present invention, the cooling water enters the cooling water channel 12 from the cooling water inlet end, and then leaves the cooling water channel 12 from the cooling water outlet end to form a cooling water circulation system.

The inventors found that the supercritical fluid in the supercritical fluid channel flows in the thermophoresis removal tube 11, and the cooling water is arranged to flow in the cooling water channel, so that the temperature inside and outside the thermophoresis removal tube 11 is different , so that a temperature gradient is formed from the axis of the thermophoresis removal tube 11 toward the tube wall, that is, the temperature near the axis of the thermophoresis removal tube 11 is higher, and the temperature gradually decreases toward the tube wall, so that the supercritical fluid Under the action of the temperature field, the particles produce thermophoresis, that is, the particles are subjected to the force from the hot zone side to the cold zone side, which makes the molecules in the supercritical fluid move violently, and the number of collisions between particles per unit time is relatively high. The number of collisions between molecules in the cold zone is less, and the difference in the number of molecular collisions and energy transfer between the two sides causes the particles to move from the higher temperature to the lower temperature zone, so that the particles are deposited on the thermophoresis removal tube 11 .

According to the present invention, the flow direction of the supercritical fluid in the thermophoresis removal tube 11 is opposite to the flow direction of the cooling water in the cooling water channel 12, so that the cooling of the supercritical fluid can be achieved relatively quickly.

In the present invention, the flow rate of the supercritical fluid is 0.4 m/s to 1.6 m/s.

The inventors found that if the flow rate of cooling water is too small, the cooling effect is not obvious, so that the thermophoresis effect of the supercritical fluid is not obvious, resulting in poor particle deposition effect and affecting the removal efficiency; The supercritical fluid is overcooled, so that the temperature of the supercritical fluid drops below the supercritical temperature and is cooled to a non-supercritical state, resulting in the inability to realize the circulation of the supercritical fluid.

According to the present invention, the flow rate of the cooling water is 0.2 to 2.0 m/s, preferably 0.4 m/s to 1.6 m/s.

According to the present invention, the cooling water can be selected from various normal temperature water sources, and the cooling water can be recycled after being cooled by the cooler.

According to the present invention, several thermophoretic removal tubes 11 are distributed side by side in the deposition tube section 9 .

According to a preferred embodiment of the present invention, the thermophoresis removal tube 11 is a straight tube.

In the present invention, when the thermophoresis removal tube 11 is a straight tube, the supercritical fluid first enters the filter tube section, removes a part of the particulate impurities through the filter membrane 5 of the filter tube section, and then enters the thermophoresis removal tube 11 of the deposition tube section 9, The removal of particles in the supercritical fluid is achieved under the combined effects of the expansion effect and the thermophoresis effect, thereby realizing the purification of the supercritical fluid.

According to another preferred embodiment of the present invention, the thermophoresis removal tube 11 is a spiral tube.

In the present invention, when the thermophoresis removal tube 11 is a spiral tube, the supercritical fluid flows into the thermophoresis removal tube 11. When the supercritical fluid flows from top to bottom, it is affected by the centrifugal force brought about by the structure of the spiral tube. Under the action of the centrifugal force, the particles are deposited on the inner wall of the thermophoretic removal tube 11. At the same time, the movement process of the supercritical fluid in the spiral tube is more complicated, and many small eddies are generated, the laminar flow is destroyed, and the adjacent flow There is not only sliding but also mixing between the layers, resulting in turbulent flow of the supercritical fluid. The existence of the turbulent flow promotes the removal of particulate impurities to the inner wall of the thermophoretic removal tube 11 . Therefore, in the present invention, when the thermophoresis removal tube 11 is a spiral tube, the supercritical fluid first passes through the filter membrane of the filter tube section to remove a part of the particulate impurities, and then enters the thermophoresis removal tube 11 of the deposition tube section. Under the multiple effects such as centrifugal force, turbulence and thermophoresis effect, the particles are removed to the inner wall of the thermophoresis removal tube 11, thereby realizing the purification of the supercritical fluid.

According to the present invention, the thermophoretic removal tubes 11 are distributed in discontinuous or continuous distribution, preferably discontinuous distribution. For example, a honeycomb structure distribution.

The inventors have found that if a plurality of thermophoresis removal tubes 11 are distributed intermittently, the cooling water can fully contact the tube wall of the thermophoresis removal tube 11, so that the wall of the thermophoresis removal tube 11 is sufficiently cooled to form a cold wall surface. , which can maximize the contact area between the supercritical fluid and the cold wall surface, enhance the thermophoretic effect, improve the thermophoretic deposition efficiency, and then improve the particle removal efficiency.

According to the present invention, several thermophoretic removal tubes 11 are distributed in a honeycomb pattern, and a thermophoretic removal tube 11 is arranged in the center. shown in Figure 2.

According to the present invention, a particle collecting box 15 for collecting particles is connected below the deposition pipe section 9 .

According to the present invention, in the deposition tube section, a compressed air inlet is provided above the thermophoresis removal tube 11, and a compressed air inlet valve 7 is provided at the compressed air inlet. When the valve is opened, the compressed air pump 8 passes high-pressure air into the deposition chamber. In the supercritical fluid channel of the pipe section 9, the high-pressure air enters into the thermophoresis removal tube 11 to clean the particles deposited on the inner wall of the thermophoresis removal tube 11, and open the particles between the deposition tube section 9 and the particle collection box 10. At the outlet valve 16, the cleaned particles are collected into the particle collection box 15, thereby completing the removal of the particles.

By using high pressure air to clean the particles deposited on the thermophoresis removal tube 11, the present invention avoids the complicated process of disassembling and cleaning the thermophoresis removal tube 11, the particle removal process is simple and the work efficiency is high.

According to the present invention, a deposition tube section 9 and a particle collection box 15 are set as a thermophoretic deposition unit, and the device includes 1 to 9, preferably 3 to 9 thermophoretic deposition units, and the thermophoretic deposition units pass through the deposition tube section 9 at the beginning and end. Connected in series, preferably, the supercritical fluid outlet section of the previous deposition tube section 9 is connected with the inlet end of the next deposition tube section 9, that is, the outlet valve of the supercritical fluid of the previous deposition tube section 9 is used as the next deposition tube section 9 supercritical fluid inlet valve.

According to the present invention, the pipe inner diameter of the transition pipe section is smaller than the pipe inner diameter of the deposition pipe section 9 .

According to the present invention, the transition pipe section and the deposition pipe section 9 are made of stainless steel, preferably low carbon austenitic stainless steel, more preferably low carbon austenitic stainless steel with corrosion resistance, high temperature resistance and radiation resistance.

According to the present invention, the pipe wall surfaces of the transition pipe section and the deposition pipe section 9 are coated with a nano coating, preferably a 150-500 μm epoxy coating for nuclear power equipment.

The inventors found that when the supercritical fluid contains radioactive high-temperature supercritical fluid, in order to prevent the removal device from generating radiation to the staff during the removal work and affecting the health of the staff, it is necessary to shield the radioactive particles of the supercritical fluid generated radiation.

According to the present invention, shielding materials are also provided on the outer walls of the pipes of the transition pipe section and the deposition pipe section 9, and the shielding materials are preferably selected from Al-B ₄ C composite materials, PVC-PE composite materials or lead boron polyethylene, etc. In addition to the device's role in preventing radioactive particle radiation.

Another aspect of the present invention provides the use of the supercritical fluid particle removal device according to the first aspect of the present invention for removing radioactive particles with a particle size of 0.1-10 μm in a supercritical fluid, preferably for removing radioactive particles in a supercritical fluid Radioactive particulate impurities with a particle size of 0.1 to 2.5 μm.

Another aspect of the present invention provides a method for purifying supercritical fluid using the supercritical fluid particle removal device of the first aspect of the present invention, the method comprising the following steps:

Step 1, install the supercritical fluid fine particulate matter removal device in the supercritical fluid pipeline;

According to the present invention, in step 1, the supercritical fluid particle removal device is installed in the supercritical fluid pipeline. At this time, the supercritical fluid pump 1 and the filter pipe section valve 2 are in a closed state, and the compressed air pump 8 and the compressed air inlet valve are in a closed state. 7 is the closed state, the supercritical fluid inlet valve 6 and the supercritical fluid outlet valve 17 are in the open state, and the particle outlet valve 16 is in the closed state.

In step 2, the cooling water is circulated, and then the supercritical fluid enters the transition pipe section and the deposition pipe section (9) to remove particulate matter.

According to the present invention, in step 2, after the supercritical fluid particle removal device is installed or prepared, the particles in the supercritical fluid are removed.

According to the present invention, in step 2, the cooling water is circulated, the cooling water inlet valve 14, the cooling water pump 13 and the cooling water outlet valve 10 are opened, and cooling water is introduced into the cooling water channel 12, and the temperature of the cooling water is lower than that of the supercritical fluid. The temperature, the temperature difference between the cooling water temperature and the supercritical fluid is in the range of 150-400K, preferably 200-350K, more preferably 250-300K, forming a cooling water circulation system.

According to the present invention, in step 2, the filter pipe section valve 2 is opened, and the supercritical fluid flows through the filter membrane 5 through the supercritical fluid pump 1 for particle removal, and then enters the thermophoresis removal pipe 11 .

According to the present invention, in step 2, the filter section valve 2 is opened, the supercritical fluid pump 1 is turned on, the supercritical fluid enters the filter section through the supercritical fluid pump 1, the supercritical fluid first passes through the filter membrane 5, and a part of the particles are deposited on the filter membrane 5, and then the supercritical fluid enters into the supercritical fluid pipeline of the deposition pipe section 9 through the supercritical fluid inlet valve 6, and then shunted to several thermophoresis removal tubes 11, the particle impurities in the supercritical fluid are in the expansion and contraction effect. , thermophoretic effect, preferably also including the combined action of centrifugal force and turbulent flow, deposited on the inner wall of the thermophoretic removal tube 11 to achieve removal of particles, thereby achieving supercritical fluid purification.

Step 3. When the removal is completed, the supercritical fluid inlet valve 6 and the supercritical fluid pump 1 are closed.

According to the present invention, in step 3, after the removal is completed, the filter pipe section valve 2, the supercritical fluid inlet valve 6 and the supercritical fluid pump 1 are closed, so that the supercritical fluid no longer flows into the filter pipe section and the deposition pipe section 9, thereby enabling Subsequently, the particles in the thermophoretic deposition tube 11 are cleaned.

In the present invention, in practical applications, different application conditions, equipment and systems have different requirements for the concentration of fine particles, and the concentration of fine particles that meets the requirements can be adjusted according to actual requirements, and the concentration of fine particles in the supercritical fluid can be passed through the supercritical fluid. Radioactive intensity was detected.

According to the present invention, in step 3, the particulate matter in the supercritical fluid is periodically removed according to actual needs. For example, the device of the present invention is used for particle removal. When the radioactivity in the supercritical fluid is less than 4×10 ⁵ Bq, the removal can be stopped and the removal is completed.

Step 4, cleaning the inner wall of the thermophoresis removal tube (11).

According to the present invention, in step 4, the supercritical fluid no longer enters the filter tube section and the deposition tube section 9, and the particles in the thermophoresis removal tube 11 are cleaned.

According to the present invention, in step 4, the particle outlet valve 16, the air compression inlet valve 7 and the air compression pump 8 are opened, and a high-temperature fluid is optionally introduced into the cooling water channel 12 to clean the inner wall of the thermophoresis removal pipe 11. , so that the particles deposited on the wall of the thermophoresis removal tube 11 fall off from the tube wall.

According to the present invention, in step 4, the air compression inlet valve 7 is opened, the air compression pump 8 is turned on, and high-pressure air is used to clean the particles deposited on the inner wall of the thermophoresis removal pipe 11, and the cleaned particles are removed from the thermophoresis removal pipe 11. The inner wall of the tube falls off, and moves along the thermophoresis removal tube 11 in the direction of high-pressure air until it falls into the particle collection box 15 to collect particles.

According to the present invention, in step 4, a high-temperature fluid is optionally introduced into the cooling water channel 12, and the temperature of the high-temperature fluid is higher than the temperature in the thermophoresis removal tube 11, so that a temperature gradient is formed between the tube wall and the tube, resulting in thermophoresis. Then, the particles deposited on the inner wall of the thermophoretic removal tube 11 are subjected to the force from the inner wall of the tube to the axis of the tube, so that the particles fall off the inner wall of the tube and fall into the particle collection box 15 under the action of high-pressure air.

In the present invention, the high pressure air is optionally used in conjunction with the thermophoresis effect to clean and remove the particles deposited on the inner wall of the thermophoresis removal tube 11 , and the cleaned particles fall into the particle collection box 15 .

Step 5. After cleaning, the particles are collected into the particle collection box 15.

According to the present invention, in step 5, after a certain period of time, when the particles on the wall of the thermophoretic removal tube 11 are cleaned, no more particles enter the particle collection box, the collection process ends, and the particle outlet valve 16 is closed to remove the particles. The particles in the collection box 15 are cleaned to complete the particle removal process.

The supercritical fluid particle removing device of the present invention has a simple structure and is suitable for large-scale industrial production applications; The removal device can remove particles with a particle size of less than 2.5 μm, and the removal device is equipped with a particle collection box outside the pipeline, and uses high-pressure air cleaning and thermophoresis effect to clean and collect the particles on the inner wall of the thermophoretic removal pipe, improving the efficiency of the removal process. removal efficiency.

Example

Example 1

A supercritical fluid particle removal device, the device includes a filter pipe section and a deposition pipe section, the supercritical fluid pipe is connected with the filter pipe section, a supercritical fluid pump and a filter pipe section valve are arranged in the middle, and the filter pipe section is provided with two nanofiltration membranes, The nanofiltration membrane is a nanofiltration membrane that can filter particles of 0.1 to 2.5 μm, and the nanofiltration membrane is fixed on the filter tube section through a sealing gasket and a sealing screw. A supercritical fluid inlet valve is arranged between the filter pipe section and the deposition pipe section.

The deposition tube section includes a supercritical fluid channel and a cooling water channel. The inner diameter of the deposition tube section is 20 cm. The supercritical fluid channel includes 9 thermophoresis removal tubes, which are distributed in a honeycomb structure, as shown in Figure 2. There is a heat exchanger in the middle. The thermophoresis removal tube and the other 8 thermophoresis removal tubes are evenly distributed around the middle thermophoresis removal tube, the inner diameter of the thermophoresis removal tube is 2cm, and the length of the deposition tube section is 1m. The thermophoresis removal tube is a straight tube, and the two ends of the thermophoresis removal tube are connected through a connecting plate. The distance of the supercritical fluid flowing in the removal device, that is, the length of the process is about 10m. The cooling water enters the cooling water pipeline through the cooling water inlet valve and leaves the cooling water outlet valve to form a cooling water circulation system.

A particle collection box is connected below the deposition pipe section, and a particle outlet valve is arranged between the deposition pipe section and the particle collection box.

There are three sedimentation tube sections, and there is a particle collection box under each sedimentation tube section. The three sedimentation tube sections are connected in series or end-to-end. The supercritical fluid inlet end of the first sedimentation tube section is connected to the filter tube section, and the first sedimentation tube section The supercritical fluid outlet end of the second deposition tube section is connected with the supercritical fluid inlet end of the second deposition tube section, a supercritical fluid outlet valve is arranged in the middle, and the supercritical fluid outlet end of the second deposition tube section is connected with the supercritical fluid of the third deposition tube section. The inlet end is connected, the supercritical fluid outlet valve is arranged in the middle, and the supercritical fluid outlet end of the third deposition pipe section is connected with the supercritical fluid pipeline.

The pipes of the filter pipe section and the deposition pipe section are made of low carbon austenitic stainless steel material with low carbon corrosion resistance, high temperature resistance and radiation resistance. _- Shielding material composed of B4C composite material.

Example 2

The supercritical fluid is purified by using the supercritical fluid particle removal device of Example 1 to remove the radioactive particle impurities therein.

Install the supercritical fluid particle removing device of Example 1 of the present invention on the supercritical fluid pipeline;

Open the cooling water inlet valve and cooling water outlet valve, pass cooling water into the cooling water channel, the cooling water flow rate is 1.6m/s; open the supercritical fluid inlet valve, open the filter section valve, open the supercritical fluid pump, supercritical fluid The fluid flows through the filter membrane at a flow rate of 1.6m/s through a supercritical fluid pump for removal, and then enters the thermophoresis removal tube;

The radioactive intensity of the test supercritical fluid before entering the removal device is 2×10 ⁶ Bq, and the radioactive intensity of the supercritical fluid flowing out of the removal device after 10s is 4×10 ⁵ Bq, which meets the requirements and stops the removal;

After the removal is over, close the supercritical fluid inlet valve and supercritical fluid pump, so that no supercritical fluid flows into the filter pipe section and the deposition pipe section, open the particle outlet valve, air compression inlet valve and air compression pump, in the cooling water channel The high-temperature fluid is introduced, and the inner wall of the thermophoresis removal tube is cleaned by the combined action of high-pressure air and thermophoresis effect, and the particles are collected in the collection box. Complete the particle removal process.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc. indicate the orientation or position The relationship is based on the orientation or position relationship under the working state of the present invention, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, Or an integral connection is common; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be stated that these specific embodiments are only illustrative explanations of the present invention, and do not constitute any limitation to the protection scope of the present invention. Various improvements, equivalent replacements or modifications can be made to the technical content of the present invention and its embodiments without departing from the spirit and protection scope of the present invention, which all fall within the protection scope of the present invention. The scope of protection of the present invention is determined by the appended claims.

Claims (12)

1. A supercritical fluid particle removing device is characterized by comprising a filtering pipe section for filtering particles and a deposition pipe section (9) which is connected with the filtering pipe section and enables the particles to be deposited, wherein supercritical fluid sequentially enters a transition pipe section and the deposition pipe section (9) to remove the particles;

the filtering pipe section is provided with a filtering film (5), the inner diameter of the transition pipe section is smaller than that of the deposition pipe section (9),

the deposition pipe section (9) comprises a supercritical fluid channel for supercritical fluid circulation, the supercritical fluid channel comprises a thermophoresis removal pipe (11), the thermophoresis removal pipe (11) is a straight pipe or a spiral pipe,

in the deposition pipe section (9), the supercritical fluid passage is removed, and the remaining space is a cooling water passage (12),

a particle collecting box (15) is connected below the deposition pipe section, a compressed air inlet valve (7) is arranged above a thermophoresis removing pipe (11) of the deposition pipe section (9), a compressed air pump (8) enables compressed air to enter a supercritical fluid channel of the deposition pipe section (9) from the compressed air inlet valve (7) to clean particles deposited on the inner wall of the thermophoresis removing pipe (11), and the removed particles are collected by the particle collecting box (15),

the pipelines of the transition pipeline section and the deposition pipeline section (9) are both made of stainless steel materials, and the outer walls of the pipelines of the transition pipeline section and the deposition pipeline section (9) are also provided with radiation-proof shielding materials.

2. The device according to claim 1, wherein the filtering membrane (5) is a filtering membrane capable of filtering fine particles with the particle size of 0.1-10 μm, and the filtering tube section is detachable.

3. The device according to claim 1 or 2, characterized in that the thermophoretic removal tubes (11) are provided in a plurality, and the two ends of the thermophoretic removal tubes (11) are communicated.

4. The apparatus according to claim 1, characterized in that in the deposition pipe section, the cooling water channel (12) communicates with a cooling water inlet port provided with a cooling water inlet valve (14) and a cooling water outlet port provided with a cooling water outlet valve (10) to form a cooling water circulation system.

5. The device according to claim 1, characterized in that the thermophoretic removal tubes (11) are distributed intermittently or continuously.

6. The device according to claim 5, characterized in that the thermophoretic removal tubes (11) are distributed intermittently.

7. The device according to claim 6, characterized in that the thermophoretic removal tubes (11) are distributed in a honeycomb structure.

8. The device according to claim 1, characterized in that there are 1-3 transition pipe sections, one deposition pipe section (9) and one particle collection box (15) are one thermophoretic deposition unit, and the device comprises 1-9 thermophoretic deposition units which are connected end to end in series through the deposition pipe sections (9).

9. The apparatus of claim 8, wherein the apparatus comprises 3-9 thermophoretic deposition units.

10. The device according to claim 9, characterized in that the conduits of the transition and deposition conduit sections (9) are of low carbon austenitic stainless steel material.

11. Use of the device according to one of claims 1 to 10 for removing particles with a particle size of 0.1 to 10 μm from a supercritical fluid.

12. A method for purifying a supercritical fluid using the removal device of any one of claims 1 to 10, comprising the steps of:

step 1, installing a supercritical fluid fine particle removal device in a supercritical fluid pipeline;

step 2, cooling water circulation is carried out, and then the supercritical fluid sequentially enters a transition pipe section and a deposition pipe section (9) to remove particles;

step 3, closing the supercritical fluid inlet valve (6) and the supercritical fluid pump (1) after the removal is finished;

step 4, cleaning the inner wall of the thermophoresis removing pipe (11);

and 5, finishing the cleaning, and collecting the particles into a particle collecting box (15).

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