Filter material and device for filtering or purifying gas and liquid

Abstract

The utility model discloses a filter material and a device for filtering or purifying gas and liquid. The utility model relates to a filter material for filtering or purifying gas and liquid. The filter material consists of a felt-like fibrofelt formed by micron-scale polymer fibers, glass fibers, ceramic fibers or metal fibers and an adsorption material positioned in gaps of the fibrofelt or on the fiber surface of the fibrofelt. The filter material disclosed by the utility model can resist impact of high temperature, high pressure and high flow, has good flexibility, can optimize the filtering and purifying effects, can be cut into any required shape and folded into a wave-shaped wrinkle structure or stacked together, and can be used for filtering and purifying. The device has a wide application prospect in the fields of purification of various radioactive gases in gas masks and closed spaces and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of filter material for filtering or purifying gas, liquid and preparation method and device, and a kind of filter material for efficiently capturing tellurium in gaseous medium and device. BACKGROUND

[0002] The device for filtering or purifying gas or liquid can be divided into many kinds, such as filter screen or some adsorption material, needle-punched filter felt as an improved technology for filter screen is also more common. CN114832507A discloses a filter felt formed by interlacing multiple layers of metal fibers and other materials. This filter felt composed of multiple fibers can withstand high temperatures, maintain filtering effect, and has the advantages of good purification and filtering efficiency. However, its preparation is relatively complex, and the disclosed method cannot prepare filter material for filtering or purifying specific components in gas or liquid.

[0003] On the other hand, long-lived actinides and volatile radionuclides (such as Cs, Te, I, Tc, Kr, etc.) are produced in nuclear power production due to nuclear fission processes, and the cladding material will crack due to overheating of the fuel rod, causing coolant loss and release of highly toxic and volatile radionuclides. How to effectively capture, remove and separate volatile radionuclides such as Cs, Te, I, Tc, Kr, etc. from waste gas stream is a current issue that needs to be addressed for nuclear facility safety and radiation. SUMMARY

[0004] One object of the present utility model is to provide a filter material that can overcome the shortcomings of the prior art and effectively filter or purify gas and liquid. The second object of the present utility model is to provide a filter material for effectively capturing Te.

[0005] The filter material for filtering or purifying gas and liquid of the present utility model is composed of a fibrous felt similar to felt formed by micron-scale high molecular fibers or glass fibers or ceramic fibers or metal fibers and an adsorption material in the interstices of the fibrous felt or on the surface of the fibers of the fibrous felt.

[0006] The present invention provides a filter material for filtering or purifying gases and liquids, which may also comprise a "sandwich" structure comprising a fiber mat formed of micron-sized polymer fibers, glass fibers, ceramic fibers, or metal fibers in a felt-like configuration; an adsorption layer composed of adsorption material located within the interstices of the fiber mat or on the fiber surfaces of the fiber mat; and protective layers composed of arbitrary fibers disposed above and below the adsorption layer. The adsorption material in the adsorption layer of the present invention is located within the interstices formed by the fiber material. The "sandwich" structure, in which protective layers are provided on both sides of the adsorption layer, effectively prevents particles from falling during filtration or purification operations, thereby affecting the subsequent purification or filtration of gases and liquids. The present invention's "sandwich" structure is particularly suitable for filtration operations involving large flows and / or high pressures.

[0007] The filter material of the present invention is a paper or traditional felt-like material formed by a papermaking process similar to that of paper. Its preparation method is to separate the dissociated fiber material from the dissociation liquid to obtain a "formed" filter material, while the adsorbent material is directly retained in the voids within the felt or deposited on the fiber surface. Any material that can be dissociated and dispersed can be easily loaded into the fiber felt. The present invention can address the shortcomings of the prior art. The filter material of the present invention is resistant to high temperatures and high pressures, and has excellent toughness and filtering and purification effects. It can be cut into any desired shape, folded into a wavy pleated structure, or stacked together, allowing for flexible design of the structure and shape of the integral reactor. Therefore, the material of the present invention has broad application prospects in the fields of gas masks and purification of various radioactive gases in confined spaces.

[0008] This novel filter material for efficiently capturing tellurium in gaseous media fills a gap in my country's protection and purification of radioactive gaseous tellurium. The porosity of this capture material can be adjusted by varying the amount of adsorbent material used and the pressure during the molding process. This filter material can partially or even completely eliminate the effects of internal diffusion, offering low resistance and a three-dimensional mesh structure that effectively avoids undesirable fluid distribution phenomena such as channeling and backmixing caused by packing, as well as radial diffusion restrictions. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the structure of the decomposed adsorption layer and the protective layer of the present invention.

[0010] Figure 2 This is a schematic diagram of an embodiment of a device for capturing tellurium in a gas medium according to the present invention.

[0011] Figure 3 This is the XPS spectrum of the Ag capture filter adsorption layer.

[0012] Figure 4 It is the XRD spectrum of the adsorption layer of the capture filter material.

[0013] Figure 5 It is the XRD spectrum of the capture filter material protective layer.

[0014] Figure 6 It is the filtration performance of the capture filter material for gaseous tellurium.

[0015] Figure 7 This is the XPS spectrum of the protective layer Te after the filter captures the adsorption of gaseous tellurium.

[0016] Figure 8 This is the XPS spectrum of the Te adsorption layer after the capture filter material adsorbs gas tellurium.

[0017] Figure 9 It is the pressure drop across a single layer of capture media at different flow rates.

[0018] Figure 10 It captures the stress conditions of the filter material under different deformation degrees.

[0019] Figure 1 and Figure 2 Middle: 1 is the input port on the tubular object, 2 is the stainless steel tubular object, 3 is the lower protective layer, 4 is the adsorption layer, 5 is the upper protective layer, 6 is the fixing bolts and nuts connecting the tubular object and the upper pipe cover, 7 is the pipe cover, and 8 is the output port on the pipe cover. DETAILED DESCRIPTION

[0020] The present invention is explained below with reference to the embodiments.

[0021] The filter material for filtering or purifying gas and liquid in the present invention is composed of a felt-like fiber felt formed by micron-sized polymer fibers or glass fibers or ceramic fibers or metal fibers and an adsorbent material in the gaps of the fiber felt or on the fiber surface of the fiber felt. The adsorbent material in the present invention can be any existing powdered adsorbent material, such as activated carbon powder or bentonite, or some other special adsorbent material, such as the silver-loaded cordierite described later in the present invention.

[0022] The filter material for filtering or purifying gas or liquid of the present invention can also be a "sandwich" structure composed of a fiber mat similar to a felt formed by micron-sized polymer fibers, glass fibers, ceramic fibers, or metal fibers, an adsorption layer composed of adsorption materials in the gaps of the fiber mat or on the fiber surface of the fiber mat, and protective layers composed of arbitrary fibers placed above and below the adsorption layer. The adsorption material can be any existing powdered adsorption material, such as activated carbon powder or bentonite, or other special adsorption materials, such as silver-loaded cordierite described later in the present invention. The advantages of adding protective layers on both sides of the adsorption layer of the present invention are to ensure the coverage rate of the captured material, reduce or avoid the loss of adsorbed particles, and ensure that the granular material does not fall during use.

[0023] The filter material for capturing tellurium in a gas medium disclosed in the present invention has a "sandwich" structure consisting of a stainless steel fiber felt similar to a felt formed by fine stainless steel fibers, an adsorption layer of adsorption material in the gaps of the stainless steel fiber felt or on the surface of the stainless steel fiber felt, and a protective layer composed of stainless steel fiber felt layers similar to a felt formed by stainless steel fibers respectively placed on both sides of the adsorption layer. The adsorption material in the adsorption layer is silver-loaded cordierite, see attached Figure 1 As shown, 3 and 5 are the left and right protective layers respectively, and 4 is the adsorption layer.

[0024] Attachment Figure 2 A schematic structural diagram of a specific embodiment of the device for capturing tellurium in a gas medium according to the present invention is given. It is composed of a section of stainless steel tubular object 2 and a tube cover 7 fixed to the tubular object. At least one piece of capture material having an adsorption layer 4 with protective layers 3 and 5 provided on both sides thereof is placed in the tubular object. The tubular object 2 and the tube cover 7 are fixed to each other by fixing bolts and nuts 6 on the flanges provided. A sealing gasket is provided between the tube 2 and the cover 7 (note: not shown in the figure), and an input port 1 and an output port 8 are provided at both ends of the tube 2 and the cover 7, respectively. In the specific preparation, multiple pieces of material consisting of protective layers and adsorption layers can be cut into suitable shapes with a tool, and placed one by one in a stainless steel tube and pressed tightly. In the actual experiment of the present invention, 18 pieces of capture filter materials were used, and Figure 2 The figure in the middle is an example, only three pieces are drawn.

[0025] The capture filter material is installed Figure 1 The capture device shown is installed in a dynamic adsorption experimental system, and the gas generation temperature, carrier gas flow rate, adsorption temperature, and system absolute pressure are set. After a certain reaction time, the carrier gas is stopped and the temperature is cooled to room temperature. The filter material is removed, and the adsorbed tellurium is eluted with concentrated nitric acid, and tested using ICP-OES.

[0026] (1) Capture filter material pressure drop test

[0027] Cut the capture filter material into a circle, place it directly in the stainless steel column, fix it with sealant on all sides, and install it into the pressure testing system to detect the pressure.

[0028] (2) Capture filter material tensile strength test

[0029] The prepared material was cut into a rectangular structure with a length of 15 cm and a width of 2 cm. Then a tensile strength tester was used to measure the stress of the capture material at different deformation distances. In order to compare its superiority, commonly used filter materials such as glass fiber were used for comparison.

[0030] Test situation:

[0031] Figure 3 The XPS spectrum shows that the 3d orbital of Ag is split into two orbitals (3 / 2d and 5 / 2d orbitals), and the binding energies of the corresponding peak positions are 368.47 and 368.47 eV, which are consistent with the binding energy of elemental silver. Obviously, elemental silver is successfully loaded on the cordierite particles.

[0032] Figure 4 The XRD spectrum of cordierite after loading silver shows the characteristic peak of silver 111, and is consistent with the standard spectrum of PDF#99-0094. Figure 5 The XRD spectrum shows that the protective layer of the capture material is stainless steel wire and complies with PDF#33-0397. This indicates that the capture material was successfully synthesized and the material has a "sandwich" shape.

[0033] (3) Test of the adsorption performance of capture filter material for gas tellurium:

[0034] In order to demonstrate the superiority of silver-loaded capture filter materials in capturing gaseous tellurium, a comparison was made between capture materials and capture materials without silver.

[0035] Figure 6 The results show that under the same experimental conditions, 14 layers can completely remove the gaseous tellurium entering the capture filter material, and the adsorption capacity of the first layer can reach 74.1 mg / g. However, the capture material without silver cannot completely remove the gaseous tellurium entering, and the adsorption capacity of the first layer (25.4 mg / g) is lower than that of the capture material. For the purification of gaseous tellurium, it is only physical filtration.

[0036] The XPS spectrum of Te revealed that ( Figure 7 and Figure 8 ) The tellurium adsorbed in the protective layer of the capture filter material is elemental tellurium, and the middle layer is Ag2Te. Therefore, the capture filter material's adsorption of gaseous tellurium includes not only chemical adsorption but also physical filtration.

[0037] Capture filter media pressure drop test:

[0038] Figure 9It shows that the flow rate and the pressure drop of the capture filter material are linearly correlated, and at a flow rate of 1.6 m / s, the single-layer filter material has a pressure difference of 1.807 kPa. Compared with existing filters, the capture filter material of the present invention has an extremely low pressure drop, which proves the feasibility of this filter material in subsequent applications.

[0039] (4) Capture filter material tensile strength test:

[0040] Figure 10 It shows that the capture filter material can withstand a force of 15.1 N, while the glass fiber can only withstand a force of 11.4 N. Therefore, the utility model has excellent pressure-bearing capacity for gaseous tellurium, and ensures the stability of the material in application scenarios with higher flow rates.

[0041] Taking the aforementioned performance experiments as an example, the utility model's high-efficiency tellurium capture filter material in gaseous media is foldable and cuttable, high-temperature resistant, high-pressure-bearing, and low-pressure-drop, enabling both physical filtration and chemical adsorption of gaseous tellurium, demonstrating excellent purification capabilities. This capture material can be used in conjunction with other system devices in a primary circuit, and can also be used as a protective mask material to protect against tellurium aerosols. The utility model's capture filter material can be applied to specifically capture tellurium gas and tellurium aerosols in flowing high-temperature gaseous environments and natural environments at room temperature, respectively. This fills a gap in my country's radioactive gaseous tellurium protection and purification capabilities and has broad application prospects.

[0042] Through experiments on the tellurium capture material of the present invention in gaseous media, it can be known that the present invention and the filter material prepared thereby can be fully used for filtering or purifying relevant gases or liquids.

[0043] The preparation of the tellurium capture material of the present invention may refer to the following:

[0044] (1) Preparation method of filter material for capturing tellurium in gaseous medium

[0045] A. Place the stainless steel wire fiber and polyacrylamide solution in a disintegrator for dissociation and dispersion, and then filter to form a protective layer of stainless steel fiber felt;

[0046] B. placing stainless steel wire fibers and a polyacrylamide solution in a disintegrator for dissociation and dispersion, and then adding silver-loaded cordierite and lignin in a mass ratio of 16:1 to the disintegrator. After sufficient dissociation and dispersion, filtering out an adsorption layer having adsorption material in its pores on the stainless steel fiber layer of step A, which is a felt-like substance;

[0047] C. Repeat step A and filter the fiber layer onto the adsorption layer formed in step B, forming a "sandwich" structure with the adsorption layer in the middle and protective layers on both sides;

[0048] D. The "sandwich" structure obtained in step C is squeezed and dried, cut into the required shape and size, and then calcined. The squeezing and drying temperature and pressure are 110°C and 300 kPa, respectively. It is then calcined at 1070°C in an atmosphere of argon:hydrogen = 4:6 to obtain a "sandwich" capture material.

[0049] The capture material prepared by the above preparation method retains silver-loaded cordierite in the gaps within the adsorption layer, see the attached Figure 1 As shown, 3 and 5 are the left and right protective layers respectively, and 4 is the adsorption layer.

[0050] (2) Preparation method of silver-loaded cordierite

[0051] (1) Pretreatment of cordierite: Grind the bulk cordierite with an agate mortar and pass it through a sieve to separate the cordierite of a specific particle size. Wash it three times with tap water and deionized water, and then wash it three times with anhydrous ethanol. Drain the liquid and dry it in a vacuum drying oven at 95 °C for 24 h. After the surface liquid is dry, calcinate it in a tube furnace (inert atmosphere, 300 °C) for 60 min to ensure that the cordierite is completely dry. Store it in a dry place for future use.

[0052] (2) Silver-loaded cordierite: A certain amount of the cordierite treated as described above was placed in a silver solution, and then shaken at 25 °C for 24 h (400 rpm). After the reaction was complete, it was washed with deionized water and anhydrous ethanol three times respectively. After draining the liquid, it was placed in a vacuum drying oven at 95 °C for 24 h. After the surface liquid was dry, the cordierite was placed in a tube furnace with an argon gas flow rate of 300 sccm. The furnace temperature was raised to 300 °C at a rate of 5 °C / min and maintained at this temperature for 240 min to remove residual moisture and reduce the silver ions to elemental silver through high-temperature calcination. The silver-loaded cordierite capture material was obtained and stored in an inert atmosphere (glove box) for use in preparing the capture material.

Claims

1. A filter material for filtering or purifying gas or liquid, characterized in that The filter material is composed of a felt-like fiber mat formed by micron-sized polymer fibers, glass fibers, ceramic fibers or metal fibers, and an adsorption material in the gaps of the fiber mat or on the fiber surface of the fiber mat.

2. A filter material for filtering or purifying gas or liquid, characterized in that The filter material is a "sandwich" structure consisting of a felt-like fiber mat formed of micron-sized polymer fibers, glass fibers, ceramic fibers, or metal fibers, an adsorption layer composed of adsorption materials in the gaps of the fiber mat or on the fiber surface of the fiber mat, and protective layers composed of arbitrary fiber layers above and below the adsorption layer.

3. A filter material for filtering or purifying gas or liquid, characterized in that The filter material has a "sandwich" structure comprising a stainless steel fiber felt formed of fine stainless steel fibers, an adsorption layer composed of adsorption material in the gaps of the stainless steel fiber felt or on the surface of the stainless steel fiber felt fibers, and a protective layer composed of stainless steel fiber felt layers formed of stainless steel fibers respectively placed on both sides of the adsorption layer.

4. A device for filtering or purifying gas or liquid, characterized in that The device is a stainless steel tube with an input port and an output port respectively provided at both ends thereof, and at least one piece of filter material according to claim 3 placed in the tube.

Images