CN112933739B

CN112933739B - Filter screen, preparation method of filter screen and filter device applying filter screen

Info

Publication number: CN112933739B
Application number: CN202110111428.3A
Authority: CN
Inventors: 俞辉; 高婷婷; 焦顺; 郑军妹
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2022-06-24
Anticipated expiration: 2041-01-27
Also published as: CN112933739A

Abstract

The invention relates to a filter screen, a preparation method of the filter screen and a filter device applying the filter screen, wherein the filter screen comprises a collecting base cloth and a nanofiber layer taking the collecting base cloth as a substrate, and the nanofiber layer is of a nanofiber structure with positive charges prepared by an electrostatic spinning method. The filter screen adopts a nanofiber structure, has the advantages of high specific surface area and high porosity, and can obviously enhance the interception effect on micro particles.

Description

Filter screen, preparation method of filter screen and filter device applying filter screen

Technical Field

The invention belongs to the technical field of air purification, and particularly relates to a filter screen, a preparation method of the filter screen and a filter device using the filter screen.

Background

Along with the rapid development of economy, the haze problem is increasingly prominent in recent years, and the haze problem becomes the focus of attention of people. Fine particles suspended in haze can enter the lung and cardiovascular system of a human body through a respiratory system, so that the problems of reduction of immunity of the human body, lung cancer and the like are caused, and therefore, air purifiers are increasingly used.

For example, the negative ion generating assembly and the filtering device using the negative ion generating assembly disclosed in the chinese patent application with patent number CN201811365806.5 (publication number CN111197823A) include a negative ion generator, a humidifying assembly for humidifying passing air, and a dehumidifying assembly for dehumidifying passing air, wherein the humidifying assembly is located upstream of the negative ion generator and the dehumidifying assembly is located downstream of the negative ion generator in a flow path of gas. Also discloses a filter device applying the negative ion generating assembly.

However, the filter screen of the patent comprises a PET support body, a PP melt-blown layer and a conductive coating formed by spraying a conductive material on the PET support body, the PET support body and the PP melt-blown layer are bonded, and then the conductive coating is sprayed on the PET support body, so that the thickness of the filter screen is not easy to master during spraying, the pore size of the filter screen is large, and the filtering effect is to be further improved.

The humidifying component is provided with a plurality of nozzles so as to improve the probability that the air passing through the inner frame brings atomized water as much as possible, but if too many nozzles are arranged, the structure is complicated, and the whole volume of the humidifying component is large due to the arrangement of an ultrasonic atomizing mechanism, an atomizing mixing chamber, a fan and the like in an area enclosed between the outer frame and the inner frame; and the atomized water is guided by the fan, so that dead angles can exist, and the atomized water cannot be brought by the air at some corners.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide a filter screen with good filtering effect aiming at the current situation of the prior art.

The second technical problem to be solved by the present invention is to provide a method for preparing the above filter screen, aiming at the current situation of the prior art.

The third technical problem to be solved by the present invention is to provide a filtering apparatus using the above-mentioned filter screen, which can further improve the filtering efficiency, in view of the current state of the prior art.

The fourth technical problem to be solved by the present invention is to provide a filtering apparatus applying the above-mentioned filter screen, which can improve the concentration of released negative ions, in view of the current situation of the prior art.

The technical scheme adopted by the invention for solving the first technical problem is as follows: the filter screen is characterized by comprising a collecting base cloth and a nanofiber layer taking the collecting base cloth as a substrate, wherein the nanofiber layer is of a positively charged nanofiber structure prepared by an electrostatic spinning method.

The technical scheme adopted by the invention for solving the second technical problem is as follows: the preparation method of the filter screen is characterized by comprising the following steps: the method comprises the following steps:

(1) adding chitin and/or chitosan into an organic solvent, and uniformly stirring at 40-80 ℃ to prepare a spinning solution with the concentration of 5-30 wt%;

the organic solvent is at least one of hexafluoroisopropanol, trifluoroacetic acid, dichloromethane, acetic acid, glutaraldehyde, dimethylacetamide-lithium chloride and N-methylpyrrolidone-lithium chloride;

(2) and cooling the spinning solution, then filling the cooled spinning solution into a needle tube, carrying out electrostatic spinning on the spinning solution, taking the non-woven fabric as a collection base fabric to obtain a nanofiber layer stacked on the non-woven fabric, wherein the non-woven fabric and the nanofiber layer jointly form the filter screen.

Chitin is the only positively charged animal cellulose found to date in nature. Because the molecular structure of the material contains unsaturated cationic groups, the material has strong adsorption effect on various harmful substances with negative charges. The chitosan is a product of chitosan deacetylated by concentrated alkali treatment, is a natural biopolymer linear polysaccharide, is a polymer rarely seen in nature and positively charged, and has good biocompatibility and biodegradability.

Preferably, the electrospinning method in the step (2) is as follows: adjusting spinning parameters to 10-25 KV, enabling the distance between the electrode wire and the collecting base cloth to be 5-30 cm, enabling the liquid supply speed to be 10-200 ul/min, enabling the rotating speed of a collector to be 300-3000 rpm, enabling the spinning temperature to be 20-30 ℃ and the humidity to be 40-70%.

Preferably, a polymer is further added into the spinning solution, and the mass ratio of the chitin and/or chitosan to the polymer is 10: 1-100: 1; the polymer is at least one of vinyl alcohol (PVA), polyethylene oxide, polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), Polyacrylonitrile (PAN), Polystyrene (PS) and Polysulfone (PSU). The advantages of adding the polymer are that: chitin and chitosan belong to organic high molecular polymers, and have more hydroxyl groups on molecular chains, hydrogen bonds are formed among the hydroxyl groups, so that the formation of electro-discharge fibers can be hindered, particularly, when bending instability and whiplash instability in jet flow occur, the spinnability of pure chitin is not good under the common condition, and the condition can be improved after the electro-spinning easy-to-form polymers are added.

The technical scheme adopted by the invention for solving the third technical problem is as follows: the utility model provides an use filter equipment of above-mentioned filter screen which characterized in that: the negative ion generating assembly is arranged on the upstream of the filter screen along the flow path of the airflow.

The technical scheme adopted by the invention for solving the fourth technical problem is as follows: a humidifying component is arranged upstream of the negative ion generating component along the flow path of the air flow and has a certain distance with the negative ion generating component, and the humidifying component comprises

The frame body is annular, and air flow passes through the area enclosed by the frame body;

the central shaft is positioned in an area enclosed by the frame body, and an accommodating cavity capable of storing water is formed in the central shaft in a hollow mode;

the atomization mechanism is arranged in the accommodating cavity and can atomize the water flowing into the accommodating cavity to form atomized water;

the extension arm, one end and center pin periphery wall link to each other, and the other end of extension arm radially extends along the center pin, the extension arm has at least two and sets up along center pin circumference interval, the inside cavity of extension arm forms the passageway with holding chamber fluid intercommunication, set up the first spout with passageway fluid intercommunication on the lateral wall of extension arm.

In order to uniformly spray the atomized water, the longitudinal section of the first nozzle is in a horn shape with a small inside and a large outside. After the atomized water passes through the change of the aperture of the first nozzle from small to large, the speed of the water vapor is reduced, and the atomized water is easier to be sprayed dispersedly.

In order to further improve the possibility of atomizing water on the air belt, the other end of the extension arm is connected with the inner peripheral wall of the frame body, the frame body is hollow, a circle of cavity is formed in the frame body and is communicated with the channel of the extension arm in a fluid mode, and a second nozzle communicated with the cavity in the fluid mode is formed in the inner peripheral wall of the frame body. Therefore, the extension arm can spray atomized water, the frame body can also spray atomized water, and the spray dead angle of the atomized water is further reduced.

In order to prevent that water from not being atomized by the atomizing piece just getting into the extension arm, the vertical extension of axis of center pin, be linked together through first intercommunication mouth between the passageway of extension arm and the holding chamber of center pin, be linked together through the second intercommunication mouth between the passageway of extension arm and the cavity of framework, first intercommunication mouth is located the upper portion in holding chamber to prevent that water from directly flowing out from first intercommunication mouth.

To further increase the likelihood of the air entraining atomized water, the second orifice is either higher or lower than the first orifice. Therefore, the first nozzle and the second nozzle are positioned on different planes to form a three-dimensional humidifying area, so that atomized water is prevented from being carried by air.

Preferably, the area of the first communication port is larger than the area of the second communication port, which is larger than the area of the second nozzle opening. Therefore, the atomized water vapor has enough kinetic energy after being accelerated for 2 times and can be smoothly discharged from the second nozzle.

The atomization mechanism can be in various structural forms, and preferably comprises

The mounting pipe is vertically arranged in the accommodating cavity, a through hole is formed in the peripheral wall of the mounting pipe, and an opening is formed in the top wall of the mounting pipe;

the water absorption rod is arranged in the installation pipe;

the atomizing piece is arranged in the mounting pipe and positioned at the upper end of the water absorbing rod, and the atomizing piece faces the opening.

In order to guarantee that the water absorption rod can smoothly send water to the atomizing piece for atomization, the water absorption rod is a cotton rod, the atomizing mechanism further comprises an elastic part acting on the cotton rod to enable the cotton rod to always keep the upper end of the elastic part in a trend of offsetting the atomizing piece.

The mounting tube can have multiple structural style, for the ease of assembling water absorption stick and atomizing piece, the mounting tube includes body, support and the apron that sets gradually from bottom to top, the through-hole is seted up on the body, the water absorption stick interpolation dress is in the body, and the upper end of water absorption stick extends the body, the up end at the body is shelved to the support lower extreme, and the upper end and the apron of support link to each other, the opening is seted up on the apron, and the shaping has vertical arm in the support, the centre gripping has the packing ring between vertical arm and the apron, the atomizing piece sets up in the packing ring.

For the life of extension filter screen, filter equipment still includes the dehumidification subassembly, on gaseous flow path, the dehumidification subassembly is located between anion generation subassembly and the filter screen, the dehumidification subassembly includes dehumidification structure, place the desiccant in the dehumidification structure. The desiccant removes excess moisture from the air.

Compared with the prior art, the invention has the advantages that: 1. the filter screen adopts a nanofiber structure, has the advantages of high specific surface area and high porosity, and can obviously enhance the interception effect on micro particles; the filter screen is provided with positive charges, so that particles with negative charges in air can be effectively filtered; 2. the filtering device also comprises an anion generating assembly, and anions are combined with microparticles in the air to form negatively charged particles with large particle size, and the negatively charged particles can be absorbed by a positively charged filter screen, so that the filtering effect of the filtering device is good; 3. the invention is also provided with a moisture absorption device, a humidifier method is adopted to improve local humidity, the anion ball is excited to generate anions, the concentration of the generated anions is high, the high-concentration anions are combined with microparticles in the air to form negatively charged particles with large particle size, and the negatively charged particles can be absorbed by a positively charged filter screen so as to further improve the filtering efficiency of the filtering device; 4. in addition, the moisture absorption device of this embodiment has seted up a plurality of first spouts on the lateral wall of extension arm for the area covered of atomized water is big, guarantees as far as all to take atomized water through the air of framework, and the moisture absorption device does not have fan system, and the free diffusion of atomizing steam, the whole cross-section of complete even cover.

Drawings

FIG. 1 is a schematic view showing the structure of a filtration apparatus according to example 1 of the present invention;

FIG. 2 is an exploded view of the filter screen and the second frame and the frame of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 2;

FIG. 4 is an exploded schematic view of the anion generating assembly and the dehumidifying assembly of FIG. 1;

FIG. 5 is an exploded schematic view of the humidifying assembly of FIG. 1;

FIG. 6 is a cross-sectional view of FIG. 5;

FIG. 7 is an enlarged view taken at A of FIG. 6;

FIG. 8 is an exploded schematic view of the atomizing mechanism of FIG. 7;

FIG. 9 is an exploded view of FIG. 5;

FIG. 10 is a schematic diagram of the operation of electrospinning;

FIG. 11 is a SEM image of a filter screen of example 1 of the present invention;

FIG. 12 is an SEM image of a filter screen of example 2 of the present invention;

FIG. 13 is an SEM image of a filter screen of example 3 of the present invention;

FIG. 14 is an SEM image of a filter screen of example 4 of the present invention;

fig. 15 is a schematic structural diagram of the testing apparatus.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example 1

As shown in fig. 1 to 10, the filtering apparatus of the preferred embodiment includes a humidifying component 1, a negative ion generating component 2, a dehumidifying component 3, and a filter screen 4, which are sequentially arranged along the airflow direction.

As shown in fig. 1, wherein a distance between the humidifying module 1 and the negative ion generating module 2 is 5cm, as shown in fig. 5 to 9, the humidifying module 1 includes a frame 11, a central shaft 12, an atomizing mechanism 13, and an extension arm 14, the frame 11 is annular, the frame 11 allows an air flow to pass through an area surrounded by the frame 11, the frame 11 is hollow, and a circle of chamber 111 is formed inside the frame 11.

The axis of the central shaft 12 extends vertically, the central shaft 12 is located in the area enclosed by the frame body 11, and the inside of the central shaft 12 is hollow to form an accommodating cavity 121 capable of storing water. The atomization mechanism 13 is disposed in the accommodating chamber 121, and the atomization mechanism 13 is used for atomizing water flowing into the accommodating chamber 121 to form atomized water.

One end of each extension arm 14 is connected with the outer peripheral wall of the central shaft 12, the other end of each extension arm 14 extends along the radial direction of the central shaft 12 and is connected with the inner peripheral wall of the frame body 11, and the three extension arms 14 are arranged at intervals along the circumferential direction of the central shaft 12. The extension arm 14 is hollow inside to form a channel 141 which is in fluid communication with the accommodating cavity 121, the channel 141 of the extension arm 14 is communicated with the accommodating cavity 121 of the central shaft 12 through a first communication port 142, the channel 141 of the extension arm 14 is communicated with the chamber 111 of the frame body 11 through a second communication port 140, the first communication port 142 is located at the upper part of the accommodating cavity 121, and the second communication port 140 is located at the upper part of the chamber 111 to prevent water stored in the accommodating cavity 121 from flowing into the channel 141 from the first communication port 142 without being atomized.

The side wall of the extension arm 14 is provided with a first nozzle 143 in fluid communication with the channel 141, and the longitudinal section of the first nozzle 143 is in a trumpet shape with a small inside and a large outside (here, the inside is close to the channel 141, and the outside is far from the channel 141). The steam can overflow outwards through the first nozzle 143, and because the first nozzle 143 is small inside and large outside, the steam coverage area is greatly increased, and after the aperture changes from small to large, the speed of the steam decreases, and the steam is easier to be scattered and sprayed into the area surrounded by the frame body 11.

The inner peripheral wall of the frame 11 is provided with a second nozzle 112 which is communicated with the chamber 111 in a fluid mode, and the second nozzle 112 is higher than the first nozzle 143. Thus, the arrangement positions of the first nozzle 143 and the second nozzle 112 are arranged one above the other, the sprayed atomized water vapor forms a three-dimensional humidifying area, the coverage area is large, and the air passing through the frame body 11 can be humidified as far as possible. The area of the first communication port 142 is larger than the area of the second communication port 140, and the area of the second communication port 140 is larger than the area of the second nozzle opening 112. This allows the water vapor to have enough kinetic energy after 2 acceleration to be smoothly discharged from the second nozzle 112.

As shown in fig. 7 and 8, the atomizing mechanism 13 includes a mounting tube, a water sucking rod 132 and an atomizing sheet 133, the mounting tube is vertically disposed in the accommodating chamber 121, a through hole 131 is disposed on a peripheral wall of the mounting tube, and an opening 130 is disposed on a top wall of the mounting tube. In this embodiment, the mounting tube includes a tube 134, a bracket 135 and a cover plate 136, which are sequentially disposed from bottom to top, the through hole 131 is formed in the tube 134, the water absorbing rod 132 is inserted into the tube 134, the upper end of the water absorbing rod 132 extends out of the tube 134, the lower end of the bracket 135 is disposed on the upper end surface of the tube 134, the upper end of the bracket 135 is connected to the cover plate 136 in an inserted manner, the bracket 135 is provided with an insert 1351, the cover plate 136 is provided with a socket 1361 for inserting the insert, the opening 130 is formed in the cover plate 136, the bracket 135 is internally formed with a vertical arm 137, a gasket 138 is clamped between the vertical arm 137 and the cover plate 136, and the atomizing plate 133 is disposed in the gasket 138 and faces the opening 130.

The installation is intraductal to be located to the excellent 132 that absorbs water, and atomizing piece 133 is located the upper end of the excellent 132 that absorbs water, and in this embodiment, the excellent 132 that absorbs water is the cotton stick, and an elastic component 139 acts on the cotton stick, makes the cotton stick remain the elastic component 139 of the trend that upper end and atomizing piece 133 offseted throughout. The resilient member 139 may be a spring with two ends that abut against the lower end of the swab and the bottom wall of the tube 134, respectively. The water in the accommodating cavity 121 is absorbed by the water absorption rod 132, and is transported to the atomizing sheet 133, and is atomized by the atomizing sheet 133 and flows into the channel 141 from the first communication port 142.

As shown in fig. 9, the frame 11 in this embodiment includes a first base and a first cover detachably disposed on the first base, the extension arm 14 includes a second base and a second cover detachably disposed on the second base, the central shaft 12 includes a third base and a third cover detachably disposed on the third base, the first base, the second base, and the third base are integrally formed to form a base 15, the first cover, the second cover, and the third cover are integrally formed to form a cover 16, and after the cover 16 is opened, water can be added into the accommodating cavity 121.

As shown in fig. 4, the structure and assembly of the anion generating module 2 and the dehumidifying module 3 in the present embodiment can refer to CN201811365806.5, the anion generating module 2 includes an inlet protective net 21, a first frame 22, anion balls 23 and a connecting protective net 24, and the first frame 22 can be made of plastic. Wherein, on the flow path of the gas, the inlet protective net 21 is positioned at the upstream of the first frame 22, the connecting protective net 24 is positioned at the downstream of the first frame 22, and the two protective nets and the first frame 22 can be respectively fixed by adhesive bonding for screening out large particles in the air. In this embodiment, the first frame 22 includes a plurality of first receiving cavities 221 arranged in a honeycomb shape, and each of the first receiving cavities 221 is filled with the negative ion ball 23.

The efficiency of the filter 4 is rapidly reduced because water molecules in the air after humidification are adsorbed by the filter 4, and therefore, the dehumidification unit 3 is provided. The dehumidifying component 3 comprises an outlet protective net 31 and a dehumidifying structure 32, the outlet protective net 31 is arranged at the downstream of the dehumidifying structure 32 and used for screening out large particles in the air, the dehumidifying structure 32 comprises a plurality of second accommodating cavities which are arranged in a honeycomb manner, and a proper amount of dehumidifying agent, such as activated carbon and silica gel drying agent, is uniformly placed in each second accommodating cavity and can be used for absorbing redundant water molecules and peculiar smell and prolonging the service life of the collecting device.

The honeycomb structure has the advantages of less used materials and high structural strength, can increase the containing amount and the surface area of the anion balls 23 and the desiccant in a limited space, and increases the excitation effect of anions and the dehumidification effect of the desiccant. The dehumidifying structure 32 may be made of plastic, the outlet protection net 31 and the dehumidifying structure 32 are fixed by adhesive, and the dehumidifying structure 32 and the connecting protection net 24 are fixed by adhesive.

As shown in fig. 2 and 3, the filter screen 4 is assembled by a second frame and a frame 42, and in this embodiment, the three components are all cylindrical to fit with the negative ion generating device. The second frame may be an integral structure, or may be formed by connecting two sub-frames as shown in this embodiment, and includes a first sub-frame 411 and a second sub-frame 412 connected by a snap. The second frame is made of an insulating material, such as ABS plastic, so as to ensure the insulating relation with the surrounding complete machine purification equipment. The frame 42 is wrapped around the side wall of the filter screen 4. The rim 42 provides support strength to the filter screen 4. The screen 4 and the frame 42 are engaged with the inside of the second frame.

In this embodiment, the preparation method of the filter screen 4 includes the following steps:

(1) 10g of chitin is added into 90g of Hexafluoroisopropanol (HFIP) which is an organic solvent, and the mixture is uniformly stirred at 40 ℃ to prepare spinning solution with the solid content of 10 weight percent, wherein the viscosity of the spinning solution is 980mPa & s.

(2) Cooling the spinning solution for 12h, then placing the cooled spinning solution into a needle tube 51, performing electrostatic spinning on the spinning solution, taking non-woven fabrics as collecting base fabrics, covering the non-woven fabrics on a collector 52 to obtain a nanofiber layer stacked on the non-woven fabrics, wherein the non-woven fabrics and the nanofiber layer together form the filter screen 4; the electrostatic spinning method comprises the following steps: the spinning parameter is adjusted to 12.4KV, the distance D between the electrode wire and the collecting base cloth is 9cm, the liquid supply speed is 25ul/min, the rotating speed of the collector 52 is 2000rpm, the spinning temperature is 25 ℃, and the humidity is 40%.

The diameter of the filter screen 4 manufactured in this example is: 50-320 nm, and the SEM drawing is shown in figure 11; the filtration efficiency of the filtration device was 99.86%.

Humidification subassembly 1, subassembly 2 takes place for the anion, dehumidification subassembly 3 and filter screen 4 can be fixed to be set up in air purification equipment's wind channel, the filter equipment of this embodiment is according to the flow path of air current, the most upstream is humidification subassembly 1, 2 distance 5cm departments take place for the subassembly with cellular anion, the air is behind humidification subassembly 1, the air combines with the aqueous vapor, get into cellular anion and take place subassembly 2, the anion ball is in the twinkling of an eye with the aqueous vapor contact, activate its ionization characteristic greatly, release a large amount of anions, the anion combines with the microparticle in the air, form great negatively charged microparticle. Then the water vapor is removed through the honeycomb dehumidification component 3, and then the water vapor is filtered by the high filtering interception capability of the nano fiber and the electrostatic adsorption force formed by positive electricity when the water vapor passes through the nano fiber positive electricity filter screen 4 device.

Example 2

Example 2 differs from example 1 in the method for producing the screen (4):

in this embodiment, the preparation method of the filter screen (4) includes the following steps:

(1) adding 15g of chitosan into 83g of organic solvent Dimethylacetamide (DMAC), adding 2g of lithium chloride, and uniformly stirring at 60 ℃ to prepare a spinning solution with the solid content of 17 wt%, wherein the viscosity of the spinning solution is 1360 mPas;

(2) cooling the spinning solution for 12 hours, then putting the cooled spinning solution into a needle tube, carrying out electrostatic spinning on the spinning solution, taking non-woven fabrics as collecting base fabrics to obtain a nanofiber layer stacked on the non-woven fabrics, wherein the non-woven fabrics and the nanofiber layer jointly form the filter screen (4); the electrostatic spinning method comprises the following steps: the spinning parameter is adjusted to be 14KV, the distance between the electrode wire and the collecting base cloth is 9cm, the liquid supply speed is 30ul/min, the rotating speed of the collector is 2000rpm, the spinning temperature is 25 ℃, and the humidity is 40%.

The diameter of the filter screen (4) prepared in the embodiment is as follows: 60-90 nm, and the SEM drawing is shown in figure 12; the filtration efficiency of this filter equipment: 99.98 percent.

Example 3

Example 3 differs from example 1 in the method for producing the screen (4):

(1) adding 9g of chitin, 11g of chitosan and 2g of polyvinyl alcohol into 76mL of trifluoroacetic acid (TFA), adding 2g of lithium chloride, and uniformly stirring at 60 ℃ to prepare a spinning solution with the solid content of 24% and the viscosity of 1890mPa & s;

(2) cooling the spinning solution for 12 hours, then putting the cooled spinning solution into a needle tube, carrying out electrostatic spinning on the spinning solution, taking non-woven fabrics as collecting base fabrics to obtain a nanofiber layer stacked on the non-woven fabrics, wherein the non-woven fabrics and the nanofiber layer jointly form the filter screen (4); the electrostatic spinning method comprises the following steps: the spinning parameter is 21KV, the distance between the electrode wire and the collecting base cloth is 15cm, the liquid supply speed is 50ul/min, the rotating speed of the collector is 2000rpm, the spinning temperature is 25 ℃, and the humidity is 40%.

The diameter of the filter screen (4) prepared in the embodiment is as follows: 80-200 nm, and the SEM drawing is shown in figure 13; the filtration efficiency of this filter equipment: 99.93 percent.

Example 4

Example 4 differs from example 1 in the method for producing the screen (4):

(1) adding 9g of chitin, 11g of chitosan and 0.2g of polyvinyl alcohol into 77.8mL of trifluoroacetic acid (TFA) and then adding 2g of lithium chloride, and uniformly stirring at 80 ℃ to prepare a spinning solution with the solid content of 22.2% and the viscosity of the spinning solution of 1890mPa & s;

(2) cooling the spinning solution for 12 hours, then filling the spinning solution into a needle tube, carrying out electrostatic spinning on the spinning solution, taking non-woven fabric as collecting base fabric to obtain a nanofiber layer accumulated on the non-woven fabric, and forming the filter screen (4) by the non-woven fabric and the nanofiber layer; the electrostatic spinning method comprises the following steps: the spinning parameter is 21KV, the distance between the electrode wire and the collecting base cloth is 15cm, the liquid supply speed is 100ul/min, the rotating speed of the collector is 2000rpm, the spinning temperature is 25 ℃, and the humidity is 40%.

The diameter of the filter screen (4) prepared in the embodiment is as follows: 60-180 nm, and the SEM drawing is shown in FIG. 14; the filtration efficiency of this filter equipment: 99.96 percent.

In the above embodiments, the method for testing the filtration efficiency of the filtration device is as follows:

referring to national standard GB/T14295, designing an air duct device, see FIG. 15, wherein the diameter of an air duct is D, injecting standard particulate matter mixed gas from a particulate matter injection port, sampling and recording the concentrations of corresponding particle sizes at an upstream sampling port and a downstream sampling port respectively, wherein the mass median diameter of particles is 0.26um NaCl aerosol, the particle concentration at the upstream sampling port is c1, the particle concentration at the downstream sampling port is c2, obtaining the penetration rate k of the particulate matters, and further obtaining the filtration efficiency eta;

in fig. 15, a1 is an air purifier module; a2 particulate injection port; a3 upstream sampling port; a4 differential pressure sampling port; a5 purifying component to be detected; a6 downstream sampling port.

Claims

1. A filtering device, characterized by comprising a screen (4) and an anion generating assembly (2), wherein the anion generating assembly (2) is positioned at the upstream of the screen (4) along the flowing path of the airflow, the screen (4) comprises a collecting base cloth and a nanofiber layer taking the collecting base cloth as a substrate, and the nanofiber layer is a positively charged nanofiber structure prepared by an electrostatic spinning method;

a humidifying component (1) with a certain distance is arranged at the upstream of the negative ion generating component (2) along the flow path of the air flow, and the humidifying component (1) comprises

The air conditioner comprises a frame body (11) in a ring shape, wherein the frame body (11) is used for allowing airflow to pass through a region surrounded by the frame body (11);

the central shaft (12) is positioned in an area surrounded by the frame body (11), and an accommodating cavity (121) capable of storing water is formed in the central shaft (12) in a hollow mode;

the atomization mechanism (13) is arranged in the accommodating cavity (121) and can atomize water flowing into the accommodating cavity (121) to form atomized water;

one end of each extension arm (14) is connected with the peripheral wall of the central shaft (12), the other end of each extension arm (14) radially extends along the central shaft (12), at least two extension arms (14) are arranged at intervals along the peripheral direction of the central shaft (12), a channel (141) communicated with the containing cavity (121) in a hollow mode is formed in each extension arm (14), and a first nozzle (143) communicated with the channel (141) in a fluid mode is arranged on the side wall of each extension arm (14);

the other end of the extension arm (14) is connected with the inner peripheral wall of the frame body (11), the frame body (11) is hollow, a circle of chamber (111) is formed in the frame body (11), the chamber (111) is in fluid communication with the channel (141) of the extension arm (14), and a second nozzle (112) in fluid communication with the chamber (111) is formed in the inner peripheral wall of the frame body (11);

the second nozzle (112) is higher or lower than the first nozzle (143).

2. The filtration device of claim 1, wherein: the method comprises the following steps:

(2) and cooling the spinning solution, filling the cooled spinning solution into a needle tube, performing electrostatic spinning on the spinning solution, collecting the non-woven fabric as a base fabric to obtain a nanofiber layer accumulated on the non-woven fabric, and forming the filter screen (4) by the non-woven fabric and the nanofiber layer.

3. The filtration device of claim 2, wherein: the electrostatic spinning method in the step (2) comprises the following steps: adjusting spinning parameters to 10-25 KV, enabling the distance between the electrode wire and the collecting base cloth to be 5-30 cm, enabling the liquid supply speed to be 10-200 ul/min, enabling the rotating speed of a collector to be 300-3000 rpm, enabling the spinning temperature to be 20-30 ℃ and the humidity to be 40-70%.

4. The filtration device of claim 2, wherein: the spinning solution in the step (1) is further added with a polymer, and the mass ratio of the chitin and/or chitosan to the polymer is 10: 1-100: 1; the polymer is at least one of vinyl alcohol, polyethylene oxide, polyacrylic acid, polyvinylpyrrolidone, polyvinylidene fluoride, polyacrylonitrile, polystyrene and polysulfone.

5. The filtration device of claim 1, wherein: the longitudinal section of the first nozzle (143) is in a horn shape with a small inside and a large outside.

6. The filtration device of claim 1, wherein: the axis of the central shaft (12) extends vertically, the channel (141) of the extension arm (14) is communicated with the accommodating cavity (121) of the central shaft (12) through a first communication port (142), the channel (141) of the extension arm (14) is communicated with the cavity (111) of the frame body (11) through a second communication port (140), and the first communication port (142) is located at the upper part of the accommodating cavity (121).

7. The filtration device of claim 6, wherein: the area of the first communication port (142) is larger than the area of the second communication port (140), and the area of the second communication port (140) is larger than the area of the second nozzle opening (112).

8. The filtration device of claim 1, wherein: the atomizing mechanism (13) comprises

The mounting pipe is vertically arranged in the accommodating cavity (121), a through hole (131) is formed in the peripheral wall of the mounting pipe, and an opening (130) is formed in the top wall of the mounting pipe;

a water absorption rod (132) arranged in the installation pipe;

and the atomizing sheet (133) is arranged in the mounting tube and is positioned at the upper end of the water sucking rod (132), and the atomizing sheet (133) faces the opening (130).

9. The filtration device of claim 8, wherein: the water absorption rod (132) is a cotton rod, the atomization mechanism (13) further comprises an elastic part (139) acting on the cotton rod to enable the cotton rod to always keep the trend that the upper end of the cotton rod is propped against the atomization sheet (133).

10. The filtration device of claim 9, wherein: the mounting tube comprises a tube body (134), a support (135) and a cover plate (136), wherein the tube body (134), the support (135) and the cover plate (136) are sequentially arranged from bottom to top, the through hole (131) is formed in the tube body (134), the water absorbing rod (132) is inserted into the tube body (134), the tube body (134) extends out of the upper end of the water absorbing rod (132), the lower end of the support (135) is placed on the upper end face of the tube body (134), the upper end of the support (135) is connected with the cover plate (136), the opening (130) is formed in the cover plate (136), a vertical arm (137) is formed in the support (135), a gasket (138) is clamped between the vertical arm (137) and the cover plate (136), and the atomizing sheet (133) is arranged in the gasket (138).

11. The filtration device of claim 1, wherein: still include dehumidification subassembly (3), on gaseous flow path, dehumidification subassembly (3) are located between anion generation subassembly (2) and filter screen (4), dehumidification subassembly (3) are including dehumidification structure (32), place the desiccant in dehumidification structure (32).