CN115650174A - Purification device for high-purity fluorine gas - Google Patents

Abstract

The invention provides a purification device of high-purity fluorine gas, which comprises: a negative pressure storage tank for storing the fluorine gas mixture from the electrolyzer device; the first vacuum pump is used for vacuumizing the negative pressure storage tank; a trapping tank for condensing the fluorine gas mixture gas from the negative pressure storage tank to remove most of the hydrofluoric acid; an adsorption tank for adsorbing the gas from the capture tank to remove a majority of the impurities; the dust filtering unit is used for carrying out dust removal treatment on the gas from the adsorption tank; a storage tank for storing the fluorine gas from the dust filtering unit; and a second vacuum pump for evacuating the storage tank.

Description

Purification device for high-purity fluorine gas

Technical Field

The invention relates to a purification device of high-purity fluorine gas.

Background

Fluorine gas is a simple substance of elemental fluorine, is light yellow, has very active chemical properties and strong oxidizability, and can be used as an oxidant in rocket fuel, a raw material of halogenated fluorine, a refrigerant, plasma etching and the like in industry. The high-purity fluorine gas is an important raw material in the field of fine chemical engineering, and is widely applied to high and new fields such as electronics, laser technology, medical plastics, electronics, new materials, aerospace and the like.

However, in the prior art, the purity of the fluorine gas produced by the conventional industrial fluorine gas preparation method is low, and further purification is required, and the existing purification process and apparatus are complicated.

Disclosure of Invention

The invention provides a purification device of high-purity fluorine gas, which can effectively solve the problems.

The invention is realized by the following steps:

an apparatus for purifying a high-purity fluorine gas, comprising:

a negative pressure storage tank for storing the fluorine gas mixture from the electrolyzer device;

the first vacuum pump is used for vacuumizing the negative pressure storage tank;

a trapping tank for condensing the fluorine gas mixture gas from the negative pressure storage tank to remove most of the hydrofluoric acid;

an adsorption tank for adsorbing the gas from the capture tank to remove a majority of the impurities;

the dust filtering unit is used for carrying out dust removal treatment on the gas from the adsorption tank;

a storage tank for storing the fluorine gas from the dust filtering unit; and

and the second vacuum pump is used for vacuumizing the storage tank.

The beneficial effects of the invention are: the purification device of the high-purity fluorine gas provided by the invention has a simple structure, can enable the fluorine gas to freely flow without additional power, prevents other power equipment from being corroded by the fluorine gas and damaged, and prolongs the service life of the purification device. Furthermore, by using the cold source in the trapping tank, most hydrofluoric acid can be quickly removed, and the separation and purification efficiency is remarkably improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic diagram showing the construction of an electrolyzer unit in a highly integrated high purity fluorine gas supply system provided by an embodiment of the present invention.

FIG. 2 is a flow chart of a process for the safe production of high purity fluorine gas as provided by an embodiment of the present invention.

FIG. 3 is a flow chart of the method for the efficient control of the electrolyzer for the safety process for the production of high purity fluorine gas according to an embodiment of the present invention.

Fig. 4 is a schematic diagram showing a part of the structure of a high-purity fluorine gas supply system of high integration according to an embodiment of the present invention.

Fig. 5 is a flow chart of a method for preparing the absorbent provided by the embodiment of the invention.

Fig. 6 is a flowchart of a safety control method of a fluorine gas purification apparatus according to an embodiment of the present invention.

FIG. 7 is a schematic view showing a part of the structure of a highly integrated high purity fluorine gas supply system provided by an embodiment of the present invention.

FIG. 8 is a flow chart of a method for distributing high purity nitrogen gas/fluorine gas mixing device according to an embodiment of the present invention.

Figure 9 is a modular schematic of a highly integrated high purity fluorine gas supply system provided by an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive efforts based on the embodiments of the present invention, are within the scope of protection of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1, an embodiment of the present invention provides anelectrolyzer apparatus 10 for the preparation of high-purity fluorine gas, theelectrolyzer apparatus 10 for the preparation of high-purity fluorine gas comprising:

the electrolytic cell comprises a closedelectrolytic cell 11, wherein afirst gas outlet 111, asecond gas outlet 112, afeeding hole 113 andheating elements 110 arranged around theelectrolytic cell 11 are arranged at the top of theelectrolytic cell 11;

the cathode bar 12, thediaphragm 13 and theanode bar 14 are arranged in theelectrolytic cell 11, wherein thediaphragm 13 is used for separating the cathode bar 12 and theanode bar 14;

a firstgas pressure sensor 17 disposed at the firstgas outlet port 111;

a secondgas pressure sensor 18 and alinkage control valve 19, which are sequentially disposed at thesecond gas outlet 112, and a negativepressure storage tank 21;

and a control unit (not shown in the figure) electrically connected to the firstgas pressure sensor 17, the secondgas pressure sensor 18 and thelinkage control valve 19, wherein the control unit is configured to control thelinkage control valve 19 to open and close according to signals of the firstgas pressure sensor 17 and the secondgas pressure sensor 18, so as to control a pressure difference between thefirst gas outlet 111 and thesecond gas outlet 112 within a predetermined range.

The structure and shape of the sealedelectrolytic cell 11 are not limited as long as they have the functions of corrosion prevention and sealing. In one embodiment, theelectrolytic cell 11 includes a cell body and a cover body matching with the cell body, and the cell body and the cover body are made of corrosion-resistant alloy, such as monel or passivated carbon steel alloy, and the like, which is not limited herein. Thefeed inlet 113 is used for feeding KHF according to the proportion₂ HF starting material. In one embodiment, thefeed port 113 comprises a potassium acidfluoride feed line 1130, a hydrogenfluoride feed line 1132, and a potassium acid fluoride/hydrogenfluoride feed line 1134. The advantage of having thefeed port 113 in three passes is: potassium hydrogen fluoride/hydrogenfluoride feed conduit 1134 may serve as a feed conduit for the initial feedstock, i.e., KHF₂ the/HF is mixed fully and then fed from the potassium bifluoride/hydrogenfluoride feed pipe 1134; during the electrolysis, HF raw material needs to be replenished regularly due to the rapid consumption of HF so as to maintain KHF in the system₂ The ratio/HF is within a predetermined range. Further, KHF is generated during the electrolysis process₂ Will also be partially entrained by the fluorine gas and will also affect the KHF₂ The ratio of KHF, therefore, needs to be replenished within a certain time₂ Raw materials. Theheating element 110 may be a resistance wire or a hydrothermal heating, and the like, without limitation, theheating element 110 is used for controlling the temperature of theelectrolytic cell 11 to be 60-110 ℃ so as to make the KHF₂ HF thawing. Thefirst gas outlet 111 and thesecond gas outlet 112 are isolated from each other by thediaphragm 13.

The number of the cathode bars 12 and theanode bars 14 is not limited, and the cathode bars and the anode bars can be arranged according to actual needs. The cathode bar 12 can be made of carbon steel or Monel material; theanode rod 14 may be made of carbon rod or the like. The diaphragm is used for isolating the hydrogen and the fluorine gas and preventing the hydrogen and the fluorine gas from interfering with each other to explode.

The firstgas pressure sensor 17 is used for acquiring first pressure information of thefirst gas outlet 111. The secondgas pressure sensor 18 is configured to obtain second pressure information of thesecond gas outlet 112. The first pressure information reflects a pressure outside thediaphragm 13, and the second pressure information reflects a pressure inside thediaphragm 13; the difference between the inside and outside pressures of thediaphragm 13 determines the liquid level L between the inside and outside of the diaphragm₁ And L₂ . If the liquid level height L₁ Or L₂ If the amount is too low, the hydrogen gas and the fluorine gas will interfere with each other and explode. Therefore, the pressure difference between thefirst gas outlet 111 and thesecond gas outlet 112 needs to be strictly controlled to be within a predetermined range.

Generally, the pressure difference between thefirst gas outlet 111 and thesecond gas outlet 112 can be controlled to be within a predetermined range by controlling thelinkage control valve 19 to open and close. Specifically, the pressure of thefirst gas outlet 111 is generally directly communicated with the atmosphere, and the pressure of thefirst gas outlet 111 can be controlled to be slightly negative by controlling the height of the exhaust port of thefirst gas outlet 111 to be 10-50 meters, so that hydrogen can be smoothly discharged. Preferably, the height of the exhaust port of thefirst gas outlet 111 is between 30 and 40 meters. And the pressure of thesecond gas outlet 112 can be controlled in a general linkage manner by the negativepressure storage tank 21 and thelinkage control valve 19. Generally, in order to discharge fluorine gas smoothly, the negativepressure storage tank 21 is generally evacuated by thefirst vacuum pump 22, and then the pressure of thesecond gas outlet 112 is controlled to be in accordance with the pressure of thefirst gas outlet 111 by the opening and closing of thelinkage control valve 19.

In other embodiments, theelectrolyzer apparatus 10 for the preparation of high purity fluorine gas further comprises: aliquid level sensor 15, which may be arranged inside or outside themembrane 13, without limitation. In one embodiment, theTheliquid level sensor 15 is provided outside thediaphragm 13, and can obtain the liquid level L outside thediaphragm 13₂ . The liquid level height L₂ It is not preferable that the amount is too low, and too low may cause hydrogen to easily cross the inside of theseparator 13, which may cause a risk. Preferably, the liquid level height L₂ The height of (A) is 10-20 cm; when the liquid level is too low, HF is fed through thefeed port 113 to reach a set height.

As a further improvement, in other embodiments, the control unit is further configured to obtain the liquid level L inside thediaphragm 13 according to the liquid level data of theliquid level sensor 15 and the first pressure information and the second pressure information₁ . Same, said liquid level height L₁ It is not preferable that the fluorine gas is too low, and the fluorine gas is liable to cross the outer side of theseparator 13 to cause a risk. Preferably, the liquid level height L₁ The height of (A) is 10-20 cm; when the liquid level is too low, HF needs to be fed through thefeed port 113; or the pressure of thesecond gas outlet 112 is controlled by the opening and closing size of thelinkage control valve 19 to reach a set height.

In other embodiments, theelectrolyzer apparatus 10 for the preparation of high purity fluorine gas further comprises: and anacidity sensor 16 for acquiring an acidity value of the electrolyte. KHF in electrolyte directly determined by acidity value₂ The ratio of HF/hydrogen is too low or too high, which results in low electrolysis efficiency, and therefore, theacidity sensor 16 can be used to obtain the acidity value of the electrolyte, thereby controlling the amount of HF added.

Referring to fig. 2, the embodiment of the present invention further provides a safe production method for high-purity fluorine gas, comprising the following steps:

s11, acquiring pressure information of two sides of adiaphragm 13, judging whether the pressure difference of the two sides of thediaphragm 13 is in a set range, if so, continuing to operate, otherwise, entering a step S12;

and S12, controlling the opening and closing of thelinkage control valve 19 to control the inner side pressure of thediaphragm 13, so that the pressure difference between two sides of thediaphragm 13 is in a set range.

In step (b)In step S11, the pressure of thefirst gas outlet 111, i.e. the pressure outside the diaphragm, is generally directly communicated with the atmosphere, and the pressure can be controlled to be a micro-negative pressure by controlling the height of the gas outlet of thefirst gas outlet 111, and the height can be generally controlled to be between 10 and 50 meters, so that the hydrogen can be smoothly discharged. The pressure at thesecond gas outlet 112, i.e., the pressure inside the diaphragm, is generally controlled in a linkage manner by the negativepressure storage tank 21 and thelinkage control valve 19. Generally, in order to discharge fluorine gas smoothly, the negativepressure storage tank 21 is generally evacuated by thefirst vacuum pump 22, and then the pressure of thesecond gas outlet 112 is controlled to be in accordance with the pressure of thefirst gas outlet 111 by the opening and closing of thelinkage control valve 19. Specifically, one atmosphere is about 101325Pa, while 1 meter of water is about 9803.9 Pa and 10cm of water is about 980.4 Pa. And KHF as electrolyte₂ The density of/HF is about twice that of water; therefore, if the pressure difference between both sides is 980.4pa, the liquid level difference between both sides is about 5 cm. In the actual production process, when the pressure difference between the two sides is greater than or equal to 980.4pa, namely the liquid level difference between the two sides is greater than 5cm, an alarm needs to be given and further adjustment needs to be carried out. More preferably, when the pressure difference between the two sides is greater than or equal to 490.2pa, namely the liquid level difference between the two sides is greater than 2.5cm, an alarm needs to be given and further adjustment needs to be carried out.

In step S12, since the negativepressure storage tank 21 is in a vacuum state, the pressure inside thediaphragm 13 can be controlled by the opening and closing of theinterlock control valve 19, and the pressure difference between both sides of thediaphragm 13 can be set within a predetermined range.

The safety production method can further comprise the following steps:

s13, acquiring the liquid level height of the inner side or the outer side of thediaphragm 13 through a liquidlevel height sensor 15;

s14, acquiring the liquid level height of the other side through the liquid level height of the inner side or the outer side and the pressure information of the two sides of thediaphragm 13;

and S15, judging whether the liquid level at least one side is lower than a set value.

In step S14, since the liquid level height on one side can be obtained by the liquidlevel height sensor 15, and the height difference on both sides can be obtained by the pressure difference information on both sides of thediaphragm 13, the liquid level height on the other side can be obtained by these two parameters. Preferably, the liquid level L on both sides₁ And L₂ And is not preferably less than 5 cm. More preferably, the liquid level heights L of both sides₁ And L₂ And is not preferably less than 10 cm.

In step S15, since the pressure difference between both sides is within the set range, when the liquid level at least one side is lower than the set value, it is indicated that the electrolyte needs to be replenished as HF is greatly reduced as the electrolysis proceeds.

Therefore, after step S15, the method further includes:

and S16, controlling thefeed port 113 to carry out HF liquid supplementing when the liquid level height of at least one side is judged to be lower than a set value. Specifically, the amount of the supplemented HF is preferably such that the initial electrolysis conditions are satisfied.

After step S15, the method further includes:

s17, acquiring the acidity value of the electrolyte through theacidity sensor 16, judging whether the acidity value is in a set range, and otherwise, controlling thefeed port 113 to perform HF liquid supplementing. In the actual electrolytic process, as the electrolysis proceeds, the HF acid is consumed and the acidity is reduced to some extent, thereby reducing the electrolytic efficiency. Therefore, it is necessary to test the acidity and control thefeed port 113 to perform HF replenishment when the acidity is lower than a set value.

After step S17 or S16, when the HF addition is completed, the method may further include:

s18, theacidity sensor 16 is used for obtaining the acidity value of the electrolyte, judging whether the acidity value is in a set range, and if not, controlling the feedingport 113 to carry out KHF₂ The liquid infusion. In the actual electrolysis process, KHF is generated as the electrolysis proceeds₂ Will be partially entrained by the gas and an increase in acidity will occur, which will also reduce the electrolysis efficiency. Therefore, it is necessary to test the acidity, and when the acidity is higher than a set value, the KHF is controlled to be applied to thefeed port 113₂ The liquid infusion.

Referring to fig. 3, an embodiment of the present invention further provides an efficient control method for an electrolytic cell, including the following steps:

s21, according to KHF₂ Mixing the electrolyte with HF in a molar ratio of 1;

s22, acquiring the acidity value of the electrolyte through theacidity sensor 16 during electrolysis, and performing HF or KHF through thefeed port 113 when the acidity exceeds a set value₂ The liquid infusion.

In step S21, electrolysis is preferably performed while controlling the HF current consumption density to 0.74 to 0.76 kg/kiloamp. In one embodiment, the electrolysis is carried out with the HF consumption current density controlled at 0.75 kg/kilo-ampere.

In step S22, the acidity set value is 39.0 to 40.5%. More preferably, the acidity set point is 39.5 to 40.2%. In one embodiment thereof, the acidity set point is about 40.0%. Specifically, when the acidity is too low, HF replenishment is performed through thefeed port 113; when the acidity is too high, KHF is conducted through thefeed port 113₂ And (5) supplementing liquid.

After step S22, the method may further include:

s23, acquiring pressure information of two sides of thediaphragm 13, judging whether the pressure difference of the two sides of thediaphragm 13 is in a set range, if so, continuing to operate, otherwise, entering a step S24;

and S24, controlling the opening and closing size of thelinkage control valve 19 to control the inner side pressure of thediaphragm 13, so that the pressure difference between two sides of thediaphragm 13 is in a set range.

In other embodiments, the method for efficiently controlling an electrolytic cell may further include:

s25, acquiring the liquid level height of the inner side or the outer side of thediaphragm 13 through the liquidlevel height sensor 15;

s26, acquiring the liquid level height of the other side through the liquid level height of the inner side or the outer side and the pressure information of the two sides of thediaphragm 13;

s27, judging whether the liquid level at least one side is lower than a set value.

After step S27, the method further includes:

and S28, controlling thefeed port 113 to carry out HF liquid supplementing when the liquid level height of at least one side is judged to be lower than a set value.

Referring to fig. 4, an embodiment of the invention provides a fluorinegas purification apparatus 20, which includes: a negativepressure storage tank 21 for storing the fluorine gas mixture gas from theelectrolyzer device 10; afirst vacuum pump 22 for evacuating the negativepressure storage tank 21; atrap tank 23 for condensing the fluorine gas mixed gas from the negativepressure storage tank 21 to remove most of the hydrofluoric acid; anadsorption tank 24 for adsorbing the gas from thecapture tank 23 to remove most of the impurities; adust filtering unit 25 for subjecting the gas from theadsorption tank 24 to dust removal treatment; astorage tank 26 for storing the fluorine gas from thedust filter unit 25; and asecond vacuum pump 27 for evacuating thestorage tank 26.

Thetrap tank 23 can condense the fluorine gas mixture gas in thetrap tank 23 by liquid nitrogen or other cold source, which removes most of hydrofluoric acid and other impurities. The temperature of thetrap tank 23 may be higher than the boiling point of fluorine gas, and preferably, the temperature of thetrap tank 23 may be controlled to-40 to-80 ℃. At this temperature, most of the impurities, especially HF acid gas, may be condensed. More preferably, the temperature of thetrap tank 23 may be controlled to-50 to-60 ℃.

In the present invention, thefirst vacuum pump 22 and thesecond vacuum pump 27 are provided, so that fluorine gas can freely flow without extra power, and the fluorine gas can be prevented from being corroded and damaged by the use of other power equipment.

In other embodiments, at least twoadsorption tanks 24 are included, so that continuous production can be realized when oneadsorption tank 24 needs to be replaced with the absorbent in the actual production process.

In other embodiments, the fluorinegas purification device 20 may further compriseabsorption tanks 28 respectively connected to theadsorption tanks 24 for absorbing the fluorine gas in theadsorption tanks 24.

The absorbent in theadsorption tank 24 is in a granular shape, has a plurality of micropores, and includes: 35 to 50 parts of sodium fluoride powder, 20 to 30 parts of potassium fluoride powder and 3 to 5 parts of binder. Preferably, the absorbent consists of 35 to 50 weight parts of sodium fluoride powder, 20 to 30 weight parts of potassium fluoride powder and 3 to 5 weight parts of binding agent, wherein the moisture content of a final product measured by the absorbent is less than or equal to 0.2 percent, and the porosity can reach more than 50 percent.

Referring to fig. 5, an embodiment of the present invention provides a method for preparing an absorbent, including the following steps:

s31, weighing 35-50 parts of sodium fluoride powder, 20-30 parts of potassium fluoride powder, 3-6 parts of binder and 3-8 parts of diluent according to mass fraction, adding into an oil bath pan at 180-200 ℃, uniformly mixing, and melting to form a mixed solution;

s32, placing the mixed solution into a spherical mold, carrying out mold pressing in a press at 180-200 ℃, and cooling at room temperature to obtain a spherical fluoride salt mixture, wherein the mold pressing pressure is 0.2-1 Mpa;

s33, putting the spherical fluoride salt mixture into a solvent to extract a diluent, wherein the solvent is a volatile organic solvent;

and S34, taking out the extracted spherical fluoride salt, volatilizing the solvent, and finally blowing the surface of the product with nitrogen to obtain the fluoride salt absorbent with high porosity.

As a further improvement, in step S31, the binder is selected from binders capable of forming sodium fluoride powder and potassium fluoride powder into good binding performance, such as polyvinylidene fluoride, styrene-butadiene rubber emulsion, carboxymethyl cellulose, and the like. In one embodiment, the binder is selected from polyvinylidene fluoride, which can form good binding performance for sodium fluoride powder and potassium fluoride powder. The content of the binder is not too high, and although the binding effect is good, the binder is easy to block a channel and is difficult to form high porosity.

The diluent is selected from materials which can infiltrate the three materials, such as benzophenone, or other ketone compounds containing benzene rings.

For further improvement, preferably, 36 to 40 parts of sodium fluoride powder, 22 to 25 parts of potassium fluoride powder, 3 to 6 parts of binder and 5 to 8 parts of diluent are weighed. In one embodiment, 36 parts of sodium fluoride powder, 24 parts of potassium fluoride powder, 5 parts of binder and 5 parts of diluent are weighed.

As a further improvement, it is preferred that the oil bath temperature be from 185 to 195 deg.C, and in one embodiment about 190 deg.C.

Generally, to increase the filling rate, it is generally pressed to form a spherical fluoride salt mixture. As a further modification, in step S32, the mixed solution is placed in a spherical mold having a diameter of 5 to 15 mm. The pressure of the die pressing needs to be strictly controlled, if the pressure is too high, the formed spherical fluoride salt mixture is too dense, and the later-stage diluent needs a long time to finish the extraction or is difficult to completely extract; in addition, if the pressure is too low, the resulting spherical fluoride salt mixture does not have sufficient strength, and the column of the absorbent is easily crushed and clogged. Therefore, it is preferable that the pressure for molding is 0.4 to 0.6MPa. In one embodiment, the pressure of the molding is about 0.55MPa.

As a further modification, in step S33, the volatile organic solvent includes ethanol, diethyl ether and a mixture thereof. The extraction time is 10-20 hours, which can be selected according to actual needs and is limited to completely extract the diluent. In one example, the spherical fluoride salt mixture was placed in ethanol for 18 hours to completely extract benzophenone.

As a further improvement, the ratio of the volatile organic solvent to the spherical fluoride salt mixture in the extraction process can be controlled to be 10-50ml. Preferably, the ratio of the volatile organic solvent to the spherical fluoride salt mixture can be controlled to be 20-30ml.

In step S34, the spherical fluoride salt after extraction is taken out, and then left at room temperature to naturally volatilize the solvent.

Example A-1

Taking 36 g of sodium fluoride powder, 24 g of potassium fluoride powder, 5 g of polyvinylidene fluoride and 5 g of benzophenone, sequentially adding the materials into a 190 ℃ oil bath kettle, uniformly stirring, melting for 1.5 hours to form a mixed solution, and putting the mixed solution into the oil bath kettle

The spherical mold is molded in a press at 190 ℃ under the pressure of 0.55Mpa, the spherical mold is cooled at 25 ℃ for 20 hours to be molded, the molded product is put into ethanol for extraction for 18 hours, after the extraction is finished, the extract is placed in the air for 36 hours to volatilize the ethanol, after the ethanol is volatilized, the surface is blown by nitrogen, and the water content of the final product is measured to be 0.14 percent, and the porosity is 57.6 percent, as shown in figure 2.

Example A-2

The same as example 1 except that: 30 g of sodium fluoride powder and 20 g of potassium fluoride powder are taken, and the moisture content and the porosity of the final product are measured to be 0.13 percent and 55.4 percent.

Examples A to 3

The same as example 1 except that: taking 50 g of sodium fluoride powder and 30 g of potassium fluoride powder, and measuring the water content of the final product to be 0.16% and the porosity to be 58.9%.

Comparative examples A to 4

The same as example 1 except that: taking 25 g of sodium fluoride powder and 15 g of potassium fluoride powder, and measuring the water content of the final product to be 0.11% and the porosity to be 48.5%.

Comparative examples A to 5

Substantially the same as in example 1, except that: 55 g of sodium fluoride powder and 35 g of potassium fluoride powder are taken, and the moisture content of the final product is measured to be 0.20 percent, and the porosity is measured to be 59.2 percent.

Comparative examples A to 6

The same as example 1 except that: taking 25 g of sodium fluoride powder and 35 g of potassium fluoride powder, and measuring the moisture content of the final product to be 0.11% and the porosity to be 48.5%.

Comparative examples A to 7

Substantially the same as in example 1, except that: 55 g of sodium fluoride powder and 15 g of potassium fluoride powder are taken, and the moisture content of the final product is measured to be 0.20 percent, and the porosity is measured to be 59.2 percent.

The examples A-1 to A-3 and the comparative examples A-4 to A-7 were subjected to the following adsorption tests:

the product is placed in a stainless steel adsorption tower, the temperature is controlled at 20 ℃, 95 percent of fluorine gas is introduced, and the flow velocity of the fluorine gas is 1m/s. The fluorine gas content and the hydrogen fluoride content volume content of the outlet gas components are detected as shown in the following table 1:

table 1 shows the gas contents of examples A-1 to A-3 and comparative examples A-4 to A-7, wherein the balance is impurity gas

From the above data, it can be seen that the adsorption performance of the absorbent to hydrogen fluoride is greatly changed as the ratio of the sodium fluoride powder to the potassium fluoride powder is changed.

To further verify the effect of the binder on the absorbent performance, examples and comparative examples are further provided as follows:

example B-1

The same as example 1 except that: 3 g of polyvinylidene fluoride is taken. The final product was tested for moisture content 0.12% and porosity 58.3%.

Example B-2

The same as example 1 except that: 8 g of polyvinylidene fluoride is taken. The final product was tested for moisture content 0.15% and porosity 56.2%.

Comparative example B-3

The same as example 1 except that: 2 g of polyvinylidene fluoride is taken. The final product was measured to have a moisture content of 0.12% and a porosity of 59.8%.

Example B-4

The same as example 1 except that: 10 g of polyvinylidene fluoride is taken. The final product was tested for moisture content 0.15% and porosity 53.1%.

The examples A-1, B-1 to 2 and comparative examples B-2 to 3 were subjected to the following adsorption test:

the product is placed in a stainless steel adsorption tower, the temperature is controlled at 20 ℃, 95 percent of fluorine gas is introduced, and the flow velocity of the fluorine gas is 1m/s. The fluorine gas content and the hydrogen fluoride content of the outlet gas component are detected according to the volume content shown in the following table 2:

table 2 shows the gas contents of examples A-1, B-1 to 2 and comparative examples B-3 to 4, wherein the balance is impurity gas

From the above data, it can be seen that the porosity and adsorption properties of the absorbent for hydrogen fluoride vary greatly with polyvinylidene fluoride. Further, in comparative example B-3, since the content of the binder was too low, the binding strength was weak and the powder could be easily removed.

To further verify the effect of compression molding pressure on the absorbent performance, examples and comparative examples are further provided as follows:

example C-1:

substantially the same as in example 1, except that: the molding pressure was about 0.2MPa. The final product was measured to have a moisture content of 0.14% and a porosity of 58.1%.

Example C-2:

the same as example 1 except that: the pressure for the molding was about 1MPa. The final product was measured to have a moisture content of 0.14% and a porosity of 55.7%.

Comparative example C-3:

substantially the same as in example 1, except that: the molding pressure was about 0.1MPa. The final product was measured to have a moisture content of 0.14% and a porosity of 58.4%.

Comparative example C-4:

the same as example 1 except that: the molding pressure was about 1.2MPa. The final product was tested for moisture content 0.14% and porosity 53.2%.

The examples A-1, C-1 to 2 and comparative examples C-3 to 4 were subjected to the following adsorption test:

the product is placed in a stainless steel adsorption tower, the temperature is controlled at 20 ℃, 95 percent of fluorine gas is introduced, and the flow velocity of the fluorine gas is 1m/s. The fluorine gas content and the hydrogen fluoride content volume content of the outlet gas components are detected as shown in the following table 3:

table 3 shows the gas contents of examples A-1, C-1 to 2 and comparative examples C-2 to 3, wherein the balance is impurity gas

From the above data, it can be seen that the porosity and adsorption properties of the absorbent to hydrogen fluoride vary greatly with pressure. Further, in comparative example C-3, since the pressing pressure was too small, the adhesive strength was weak and the powder could be easily removed. In addition, in comparative example C-4, since the pressure of the film pressure was too large, it was necessary to extract the product in ethanol for 36 hours or more after the molding to completely extract the product.

To further verify the effect of adsorption temperature on the performance of the absorbent, examples and comparative examples are further provided, as follows:

placing the product A-1 into a stainless steel adsorption tower, controlling the temperature at 10 ℃, 15 ℃,20 ℃, 25 ℃, 30 ℃, 35 ℃ and 40 ℃, and introducing 95% fluorine gas at the flow velocity of 1m/s. The fluorine gas content and the hydrogen fluoride content of the outlet gas component are detected according to the volume content shown in the following table 4:

table 4 shows the gas contents at different temperatures in example A-1, wherein the balance was impurity gas

From the above data, it can be seen that the adsorption performance of the absorbent to hydrogen fluoride is greatly changed with the change of the adsorption temperature. When the temperature is lower than 10 ℃ or higher than 35 ℃, the adsorption performance to hydrogen fluoride is significantly reduced.

The test data of the absorbent is measured based on about 95% fluorine gas, and in the present invention, the fluorine gas content after passing through thetrap tank 23 can be about 98% to 99%, and the fluorine gas content can be made to be 99.99% or more by further processing with the absorbent.

In the present invention, thefirst vacuum pump 22 and thesecond vacuum pump 27 are provided, so that the fluorine gas can flow freely without additional power, and the damage of other power equipment due to the corrosion of the fluorine gas can be prevented.

Referring to fig. 6, the embodiment of the invention further provides a method for safely controlling a fluorinegas purification apparatus 20, which includes the following steps:

s41, controlling thefirst vacuum pump 22 to work, vacuumizing the negativepressure storage tank 21, and closing a pipeline corresponding to thefirst vacuum pump 22 after the vacuumizing is finished;

s42, controlling thesecond vacuum pump 27 to work, vacuumizing the trappingtank 23, theadsorption tank 24, thedust filtering unit 25 and thestorage tank 26, and closing a pipeline corresponding to thesecond vacuum pump 27 after the vacuumizing is finished;

and S43, opening thelinkage control valve 19 to feed the negativepressure storage tank 21, and when the pressure of the negativepressure storage tank 21 reaches a set value, opening corresponding pipelines of thetrapping tank 23, theadsorption tank 24, thedust filtering unit 25 and thestorage tank 26 to perform fluorine gas purification treatment.

In steps S41 and S42, in order to make the subsequent fluorine gas have a high purity, it is necessary to reduce the degree of vacuum in the system as much as possible.

In step S43, since theadsorption tank 24 and thedust filter unit 25 have large resistance, a large pressure difference needs to be provided between the negativepressure storage tank 21 and thestorage tank 26 to smoothly purify the fluorine gas. Preferably, when the pressure in the negativepressure storage tank 21 reaches 0.5 to 0.8 atm, the fluorine gas purification process may be performed by opening thecollection tank 23, theadsorption tank 24, thedust filter unit 25, and thestorage tank 26 in correspondence to the pipelines. In one embodiment, when the pressure in the negativepressure storage tank 21 reaches 0.6 atm, the trappingtank 23, theadsorption tank 24, thedust filtering unit 25, and thestorage tank 26 are opened to perform fluorine gas purification.

Further, in step S43, the temperature of thecapture tank 23 is controlled between-40 ℃ and-80 ℃ at the same time. Preferably, the temperature of the collectingtank 23 is controlled between-50 ℃ and-60 ℃ at the same time.

Further, in step S43, the temperature of thecanister 24 is controlled to 15 to 30 ℃. Preferably, the temperature of theadsorption tank 24 is controlled to be 20 ℃.

Further, in step S43, when one of theadsorption tanks 24 is saturated and needs to be replaced, the adsorption tank is switched to anotheradsorption tank 24 for adsorption. At this time, theadsorption tank 24 requiring the replacement of the adsorbent is switched to theadsorption tank 28 to evacuate the fluorine gas, thereby preventing the occurrence of a danger.

Referring to fig. 4, the embodiment of the present invention further provides a high purity nitrogen/fluorinegas mixing device 30, wherein the high purity fluorine/nitrogengas mixing device 30 comprises: a nitrogengas supply unit 31; amixed gas tank 33 that communicates with the nitrogengas supply unit 31 and thestorage tank 26, respectively; a third vacuum pump 32 in communication with the gas-mixingtank 33 for evacuating the gas-mixingtank 33; agas pressure sensor 34 provided on thegas mixing tank 33; and amixed gas outlet 35 provided at the bottom of themixed gas tank 33.

Referring to fig. 7, thegas mixing tank 33 includes: ahorizontal tank 330; anitrogen gas pipe 331 disposed at one side of thehorizontal tank 330 and communicating with the nitrogengas supply unit 31; afluorine gas line 332 disposed at the top of thecanister body 330 and in communication with thestorage tank 26; arotating shaft 333 transversely disposed in thehorizontal tank 330 and a motor (not shown) for driving the rotating shaft to rotate; and arotating blade 334 arranged on therotating shaft 333.

One side of therotating shaft 333 is opened so that thenitrogen gas pipe 331 is inserted into therotating shaft 333. Furthermore, a plurality of air outlet holes 3332 are formed in therotating shaft 333 corresponding to two sides of therotating blade 334, and the nitrogen is discharged from the air outlet holes 3332 and mixed with the fluorine gas for distribution. Preferably, the air outlet holes 3332 are arranged in one-to-one correspondence with the blades of therotary blade 334. Since the fluorine gas has strong corrosion performance, therotating shaft 333 and therotating blade 334 are corroded. In this case, thenitrogen gas pipe 331 is extended into therotating shaft 333, and is exhausted from both sides of therotating blade 334 on therotating shaft 333, and therotating shaft 333 and therotating blade 334 are partially covered by the nitrogen gas, thereby preventing the surface of the rotating blade from being corroded by the fluorine gas. With the rotation of therotating blade 334, after the fluorine gas and the nitrogen gas are fully mixed on the side wall of thehorizontal tank 330, the corrosion performance is remarkably reduced, and the service life of the stirring device is further remarkably prolonged. The mixing ratio of the fluorine gas and the nitrogen gas can be controlled according to actual requirements.

The number of therotary blades 334 is not limited, and may be 1 to 5 groups. In one embodiment, 3 sets of therotating blades 334 are included.

Thegas pressure sensor 34 is used for detecting the pressure in thegas mixing tank 33 so as to realize gas distribution. Specifically, when thegas mixing tank 33 is evacuated, nitrogen gas and fluorine gas of predetermined pressures are respectively introduced at this time, so that accurate gas distribution of nitrogen gas and fluorine gas can be realized.

Referring to fig. 8, the embodiment of the present invention further provides a method for distributing gas of a high purity nitrogen/fluorinegas mixing device 30, which includes the following steps:

s51, evacuating thegas mixing tank 33 by the third vacuum pump 32;

s52, when the pressure in thestorage tank 26 reaches a set vacuum degree, opening a valve to charge the fluorine gas in thestorage tank 26 into thegas mixing tank 33, and when the pressure reaches a first set pressure, ending fluorine gas intake;

and S53, opening thenitrogen supply unit 31 to fill nitrogen into themixed gas tank 33, and ending nitrogen gas intake when the second set pressure is reached.

In steps S52 and S53, the gas distribution ratio of the fluorine gas and the nitrogen gas can be controlled by controlling the first set pressure and the second set pressure. The gas distribution ratio of the fluorine gas and the nitrogen gas can be adjusted according to actual needs, and is not limited herein.

In step S53, when the second set pressure is reached, the method may further include:

and S54, driving therotating blade 334 on therotating shaft 333 to slowly rotate through the motor, so that the fluorine gas and the nitrogen gas are fully mixed. The rotational speed of therotary blade 334 may be controlled below 30 rpm to prevent it from affecting the detected actual value of the pressure. The benefits of controlling the slow rotation of therotating blades 334 are: the nitrogen gas can be uniformly coated on the surface of therotary blade 334 to prevent further corrosion by the fluorine gas during the mixing process.

Referring to fig. 9, a high-integration high-purity fluorine gas supply system according to another embodiment of the present invention comprises:

anelectrolyzer unit 10 and a fluorinegas purification unit 20 integrally provided on amovable substrate 40; wherein themovable substrate 40 has a horizontal plane on which theelectrolyzer apparatus 10 is placed. The highly integrated high purity fluorine gas supply system further comprises twolevel meters 41 arranged on the horizontal plane, wherein thelevel meters 41 are respectively arranged on two straight lines perpendicular to each other on the horizontal plane, so that whether the wholeelectrolytic cell device 10 is horizontal or not is judged, and safe production is realized. Through the arrangement, the high-integration high-purity fluorine gas supply system can realize mobile safe fluorine production, and meets the requirement of industrial pure fluorine. Themovable base plate 40 may be a movable box type cargo container or the like.

As a further improvement, in other embodiments, the high-integration high-purity fluorine gas supply system may further include a high-purity fluorine/nitrogen mixing device 30 connected to the fluorinegas purification device 20, thereby being used to arrange fluorine-nitrogen mixtures of different concentrations.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. An apparatus for purifying a high purity fluorine gas, comprising:

a negative pressure storage tank (21) for storing the fluorine gas mixture gas from the electrolyzer device (10);

a first vacuum pump (22) for evacuating the negative pressure storage tank (21);

a trap tank (23) for condensing the fluorine gas mixture gas from the negative pressure storage tank (21) to remove most of the hydrofluoric acid;

an adsorption tank (24) for adsorbing the gas from the capture tank (23) to remove most of the impurities;

a dust filtering unit (25) for dust removing the gas from the adsorption tank (24);

a storage tank (26) for storing the fluorine gas from the dust filtration unit (25); and

a second vacuum pump (27) for evacuating the storage tank (26).

2. The apparatus for purifying a high purity fluorine gas according to claim 1, wherein the trap tank (23) condenses the fluorine gas mixed gas in the trap tank (23) with liquid nitrogen to remove most of hydrofluoric acid and other impurities.

3. The apparatus for purifying a high purity fluorine gas according to claim 1, wherein the temperature of the trap tank (23) is controlled to-40 to-80 ℃.

4. The apparatus for purifying a high purity fluorine gas according to claim 1, comprising at least two adsorption tanks (24) arranged in parallel.

5. The apparatus for purifying a high purity fluorine gas according to claim 1, wherein the apparatus for purifying a fluorine gas (20) further comprises absorption tanks (28) respectively connected to the adsorption tanks (24) for absorbing the fluorine gas in the adsorption tanks (24).

6. The apparatus for purifying a high purity fluorine gas as claimed in claim 1, wherein the absorber in the adsorption tank (24) is in the form of particles having a plurality of micropores, and comprises: 35 to 50 parts of sodium fluoride powder, 20 to 30 parts of potassium fluoride powder and 3 to 5 parts of binder.

7. The apparatus for purifying a high purity fluorine gas as claimed in claim 6, wherein the moisture content of the final product measured by the absorbent is 0.2% or less, and the porosity is 50% or more.

8. The apparatus for purifying a high purity fluorine gas as claimed in claim 6, wherein the absorbent is prepared by the steps of:

s31, weighing 35-50 parts of sodium fluoride powder, 20-30 parts of potassium fluoride powder, 3-6 parts of binder and 3-8 parts of diluent according to mass fraction, adding into an oil bath pan at 180-200 ℃, uniformly mixing, and melting to form a mixed solution;

s32, placing the mixed solution into a spherical mold, carrying out mold pressing in a press at 180-200 ℃, and cooling at room temperature to obtain a spherical fluoride salt mixture, wherein the mold pressing pressure is 0.2-1 Mpa;

s33, placing the spherical fluoride salt mixture into a solvent to extract a diluent, wherein the solvent is a volatile organic solvent;

and S34, taking out the extracted spherical fluoride salt, volatilizing the solvent, and finally blowing the surface of the product with nitrogen to obtain the fluoride salt absorbent with high porosity.

9. The apparatus for purifying a high purity fluorine gas as claimed in claim 8, wherein the binder is selected from polyvinylidene fluoride.

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