CN107321065B - A Recyclable High Efficiency Composite Ultrasonic Filter - Google Patents

Abstract

The invention discloses a recyclable high-efficiency composite ultrasonic filter. Including the shell, filter element and fan, the filter element is equipped with an ultrasonic transducer, and the ultrasonic transducer is placed in the middle of the filter element; the filter element includes three layers of composite filter paper, wave paper and ultrasonic transducer, and the three layers of composite filter paper are arranged in an S shape Arranged in curls, the three-layer composite filter paper is arranged with corrugated paper between the adjacent layers after S-shaped curling, and the ultrasonic transducer is placed on the corrugated paper in the middle of the filter element. The three-layer composite filter paper is made of glass fiber, activated carbon fiber and glass It is prepared by mixing cotton; it also includes an ultrasonic cleaning filter module, and the ultrasonic cleaning filter module includes an ultrasonic probe and an electrostatic membrane. The invention enhances the filtering effect of the filter element, and at the same time enables the filter element to have dual functions of filtering particles and removing harmful gases such as formaldehyde; the arrangement of the ultrasonic device improves the filtering efficiency, and enables the filter element to be used repeatedly, increasing the service life of the filter element .

Description

A Recyclable High Efficiency Composite Ultrasonic Filter

technical field

The invention relates to an air filter, in particular to a recyclable high-efficiency composite ultrasonic filter.

Background technique

With the vigorous development of modern industry, the society has made rapid progress, and people's living standards have also been rapidly improved, but what follows is the deterioration of the ecological environment, and the nature and distribution of air dust have also changed. In December 2013, smog swept across the land of my country, covering half of our country in a sea of smog. The air quality (AQI) hit new highs repeatedly, and the PM2.5 value also frequently exceeded the table. At the beginning of 2014, a new round of smog hit again, affecting a land area of about 1.43 million square kilometers, of which the area of heavy smog was about 810,000 square kilometers, and the heavily polluted weather in Beijing lasted for more than 90 hours. The smog weather brings a lot of inconvenience to people's daily life, more importantly, the smog seriously endangers people's health. PM2.5, that is, particulate matter entering the lungs, refers to particulate matter in the atmosphere with a particle size less than or equal to 2.5 microns. PM2.5 has a small particle size, is rich in a large amount of toxic and harmful substances, and stays in the atmosphere for a long time and has a long transport distance, so it has a greater impact on human health and the quality of the atmospheric environment.

In response to the current air pollution problem, people use high-efficiency filters to intercept particulate pollutants. High-efficiency filter material is the main component that plays a filtering role, and is the key to determining the accuracy of air filtration. The technical solution most similar to the present invention is to use a filter element made of ultra-fine glass fiber, which is mainly used to remove particulate matter, and also uses photocatalyst, activated carbon, etc. to remove harmful gases such as formaldehyde.

The currently used air filter technology solutions mainly include the use of ultra-fine glass fiber paper to filter particulate matter, and the use of activated carbon and photocatalyst technology to remove harmful gases such as formaldehyde. Combined with the product analysis on the market, there are many problems in the existing technology, which greatly reduces the performance of the air filter. The specific problems are as follows:

(1) Simply using glass fiber paper for filtration, the transmittance of particulate matter is relatively high, and the purification effect cannot be achieved.

(2) In order to achieve the dual effects of removing particulate matter and harmful gases, most filters use glass fiber paper filter screens and activated carbon filter screens to remove particulate matter and harmful gases respectively, but the use of multi-layer filter screens will cause the volume of the filter to change. big.

(3) The filter screen in the air filter is disposable, and some filter screens need to be replaced after less than three months of use, and the service life ranges from 3 to 18 months, which not only increases the user's use cost, but also causes Waste of resources is an indirect environmental pollution.

Contents of the invention

In order to solve the problems in the background technology, the present invention provides a recyclable high-efficiency composite ultrasonic filter.

The technical scheme adopted in the present invention is:

The invention includes a housing, a filter element installed in the housing, and a fan. The fan is placed on the upper part of the housing, and the filter element is placed on the lower part of the housing. An air inlet is opened on the side wall, an ultrasonic transducer is arranged in the filter element, and the ultrasonic transducer is placed in the middle of the filter element.

The invention uses the ultrasonic transducer to make the movement of the particles more intense, which is more conducive to the filtering of the particles by the filter element.

The filter element includes three layers of composite filter paper, wave paper and an ultrasonic transducer, the three layers of composite filter paper are arranged in an S-shaped curl, and wave paper is arranged between adjacent layers of the three-layer composite filter paper after the S-shaped curl, The ultrasonic transducer is placed on the corrugated paper in the middle of the filter element.

The wave paper adopts double-adhesive paper.

In the three-layer composite filter paper, the first layer is glass fiber, the second layer is activated carbon fiber, and the third layer is glass wool, which is specifically prepared by mixing glass fiber, activated carbon fiber and glass wool.

In the three-layer composite filter paper, the glass fiber diameter is 7 μm, the fiber length is 3-10 mm, and the mass ratio is 15%; the activated carbon fiber diameter is 2.6 μm, the fiber length is 3-10 mm, and the mass ratio is 30% %; glass fiber cotton has a diameter of 0.6 μm and a fiber length of 3 to 10 mm, accounting for 55% of the mass.

The filter element is the most critical part of the air filter, and the performance of the filter element directly determines the filtering effect. There are two parameters to judge the performance of the filter element: filtration efficiency and filtration resistance. "High efficiency and low resistance" is the best state of the filter element. Generally, the quality factor is used to comprehensively evaluate the performance of the filter element. In order to improve the performance of the filter core, the invention improves the filter paper and the composition of the filter core.

The filter paper of the present invention adopts the proportioning mode of "coarse skeleton (glass fiber) + excessive material (activated carbon fiber) + fine filling (glass wool)" to form a compound, thus ensuring the filtration efficiency and maintaining low resistance. Among them, activated carbon fiber is used as the excessive material of the filter paper. The activated carbon fiber has the effect of absorbing harmful gases such as formaldehyde, so that while ensuring the performance of the filter paper to filter particulate matter, it also has the effect of removing harmful gases.

The filtration of the three-layer filter paper of the present invention filters out the dust far smaller than the pores of the material, and is not a simple screening. The filtration mechanism can be roughly divided into inertial collision, Brownian diffusion, direct interception and electrostatic effect. Very small particles mainly carry out Brownian motion and are eventually captured; larger particles have greater momentum and a high probability of inertial collisions, and are mainly captured by inertial effects; for some small particles (0.04-0.4um), Brownian diffusion and inertial The effects are not significant, and this type of particles is the least likely to be captured.

In the invention, two ultrasonic transducers are placed in the middle of the filter element to increase the capturing ability of small particles (0.04-0.4um). Under the action of ultrasound, small particles will move more violently, and the Brownian diffusion effect will be more obvious, making it easier to capture.

It also includes installing an ultrasonic cleaning filter module outside the multilayer filter structure. The ultrasonic cleaning filter module includes an ultrasonic probe and an electrostatic membrane. The ultrasonic probe is arranged on the side of the filter element facing the filter inlet, and the electrostatic membrane is arranged on the side of the filter element facing the filter outlet. .

The present invention uses ultrasonic technology to clean the filter core module to clean the filter core, so that the particulate matter in the filter core is moved to the outside of the filter core and collected, so that the filter core can be recycled.

The electrostatic film is made of PVC material, which has good viscosity, high static resistance and good electrostatic effect. The electrostatic membrane is only placed in the air purifier when cleaning the filter element. When cleaning the air normally, the membrane must be taken out of the machine.

In the present invention, an ultrasonic cleaning filter element module is added in the filter to actively clean the filter element without taking out the filter element for replacement or manual cleaning. The cleaning principle is to use the action of ultrasound to move the particles collected by the filter element to the outside of the filter element, and collect these particles with an electrostatic membrane outside the filter element. After the cleaning is finished, the electrostatic film can be cleaned. The specific implementation is to test the resistance of the filter element in the filter. When the resistance value reaches 1.5 times of the initial resistance, the user will be reminded that the filter element needs to be cleaned.

The ultrasonic transducer includes polyurethane, a piezoelectric ceramic ring, a nylon screw, a nylon fixing piece, a rechargeable battery, pins, and a connecting wire; two nylon fixing pieces are respectively connected to two ends of the piezoelectric ceramic ring, and two nylon fixing pieces The middle is respectively connected with the two ends of the nylon screw threaded on the piezoelectric ceramic ring, and the nylon fixed piece and the piezoelectric ceramic ring are formed into a hollow fixed structure by screwing the thread between the nylon screw and the nylon fixed piece; The exterior of the structure is protected by polyurethane wrapping. A rechargeable battery is installed in the hollow space inside. The rechargeable battery is connected to the external drive circuit through a connecting line. The two ends of the piezoceramic ring are respectively connected to two pins.

The specially designed ultrasonic transducer of the present invention can be placed inside the filter element and can conveniently supply power to the driving circuit.

The internal structure of the filter of the present invention is mainly the direction of air flow, and the user is reminded to clean the filter core by measuring the resistance of the filter core.

The beneficial effects of the present invention are:

The filter structure of the present invention enhances the filtering effect of the filter element, and at the same time enables the filter element to have dual functions of filtering particles and removing harmful gases such as formaldehyde. And the filter element can be cleaned, so that the filter element can be used repeatedly.

The existing air filter on the market uses a plurality of filter elements. The design of the filter element of the present invention combines the filtering of particles and filtering of harmful gases into one, reducing the number of filter elements and optimizing the volume of the filter.

The invention improves the filtering efficiency through the arrangement of the ultrasonic device, and enables the filter core to be used repeatedly, thereby increasing the service life of the filter core.

Description of drawings

Fig. 1 is the structural three-dimensional view of filter element;

Figure 2 is a side view of the filter element;

Fig. 3 is the front view of filter element;

Fig. 4 is a schematic diagram of the ultrasonic sound field inside the filter element;

Fig. 5 is a structural diagram of an ultrasonic transducer;

Fig. 6 is the schematic diagram of ultrasonic cleaning filter element;

Figure 7 is a front view of the overall structure of the air filter;

Figure 8 is a side view of the overall structure of the air filter;

Fig. 9 is a diagram of CADR test data of an air purifier without an ultrasonic probe filter element according to an embodiment.

Fig. 10 is a diagram of CADR test data of an air purifier with an ultrasonic probe in an embodiment.

In the figure: three-layer composite filter paper 1, wave paper 2, ultrasonic transducer 3, filter element 4, fan 6, air inlet 7, air outlet 8, ultrasonic probe 9, electrostatic film 10, floating particles 11, absorption Arrived particulate matter 12, polyurethane 13, piezoelectric ceramic ring 14, nylon screw rod 15, nylon fixing sheet 16, rechargeable battery 17, pin 18, connecting wire 19 of battery and driving circuit.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 7 and 8, the present invention includes a housing, a filter element 4 installed in the housing, a fan 6 and an ultrasonic cleaning filter module, the fan 6 is placed in the upper part of the housing, the filter element 4 is placed in the lower part of the housing, and the fan 6 is placed in the upper part of the housing. There is an air outlet 8 on the side wall of the housing on the side 6, and an air inlet 7 on the side wall of the housing on the side of the filter element 4. An ultrasonic transducer 3 is arranged inside the filter element 4, and the ultrasonic transducer 3 is placed in the middle of the filter element 4. The ultrasonic cleaning filter module includes an ultrasonic probe 9 and an electrostatic membrane 10. The ultrasonic probe 9 is arranged on the side of the filter element 4 facing the filter inlet, and the electrostatic membrane 10 is arranged on the side of the filter element 4 facing the filter outlet.

As shown in Figure 1-3, the filter element 4 includes three layers of composite filter paper 1, wave paper 2 and ultrasonic transducer 3. The three layers of composite filter paper 1 are arranged in an S-shaped curl, and the three-layer composite filter paper 1 is curled in an S shape. Corrugated paper 2 is arranged between adjacent layers, and the ultrasonic transducer 3 is placed on the corrugated paper 2 in the middle of the filter element 4 .

As shown in Figure 5, the ultrasonic transducer 3 of concrete implementation adopts the structure as shown in Figure 5, specifically comprises polyurethane 13, piezoelectric ceramic ring 14, nylon screw rod 15, nylon fixed piece 16, rechargeable battery 17, pin 18, Connecting wire 19; two nylon fixing pieces 16 are respectively connected to the two ends of the piezoelectric ceramic ring 14, and the middle of the two nylon fixing pieces 16 are respectively connected to the two ends of the nylon screw 15 which is installed in the piezoelectric ceramic ring 14, and the nylon screw 15 and the nylon fixing piece 16 are screwed tightly to form a hollow fixed structure inside the nylon fixing piece 16 and the piezoelectric ceramic ring 14; , the rechargeable battery 17 is connected to the external drive circuit through the connection line 19, and the two ends of the piezoelectric ceramic ring 14 are respectively connected to two pins 18, and the pins 18 are connected to the external drive circuit after passing through the polyurethane 13.

The working process of the ultrasonic transducer: the external circuit generates an excitation electric field, and the piezoelectric ceramic ring in the ultrasonic transducer is mechanically deformed under the action of the excitation electric field, thereby generating an ultrasonic signal. For a piezoelectric ceramic with a fixed edge, when a voltage is applied to its two ends, a displacement in the vertical direction will be generated, and the displacement is linear in a certain range with the voltage applied to its two ends.

Among them, polyurethane 13 is the material of the ultrasonic probe shell, which plays the role of protecting internal devices; nylon fixing sheet 16 and nylon screw rod 15 are used to support and fix the internal structure; Charging; the drive circuit board drives the internal piezoelectric ceramic ring to generate ultrasound through the pins.

In the three-layer composite filter paper 1, the first layer is glass fiber, the second layer is activated carbon fiber, and the third layer is glass wool, which is specifically prepared by mixing glass fiber, activated carbon fiber and glass wool. In the three-layer composite filter paper 1, the glass fiber diameter is 7 μm, the fiber length is 3-10 mm, and the mass ratio is 15%; the activated carbon fiber diameter is 2.6 μm, the fiber length is 3-10 mm, and the mass ratio is 30%. ; The glass fiber cotton has a diameter of 0.6 μm, a fiber length of 3-10 mm, and a mass ratio of 55%.

Concrete implementation work process of the present invention is:

For filtering, turn on the ultrasonic transducer 3 and fan 6, so that under the action of the ultrasonic transducer 3, using the physical characteristics of the ultrasonic, the movement of the particles through the filter core is more intense, which is helpful for the contact between the particles and the filter paper. It is conducive to the full filtration of particulate matter by the filter element.

As shown in Figure 4, according to the ultrasonic sound field distribution, it can be known that the sound pressure in the near field of ultrasound is high, and the sound field distribution is dense; while the opening angle of the main lobe of ultrasound in the far field expands, and the sound pressure amplitude gradually decreases. The boundary point between the far field and the near field z _g =a ² /λ, a represents the radius of the sound source, and λ represents the wavelength of the sound wave. Therefore, considering the size of the air purifier, choose an appropriate ultrasonic frequency to optimize the ultrasonic effect. Since the specific filter screen is 60*60*19cm. The frequency of the ultrasonic transducer used is 100-120KHZ, and the near field range is 32-35cm, which can cover the entire filter screen and meet the requirements.

After a long time of filtering and using, by testing the resistance of the filter element in the filter, when the resistance value reaches 1.5 times of the initial resistance, the filter element will be cleaned.

Turn on the ultrasonic cleaning filter element module during cleaning. The specific implementation is to place two ultrasonic probes on the inlet side of the filter element. The membrane 12 is adsorbed and collected to obtain the absorbed particulate matter 12 (the greater the number, the better the cleaning effect), thereby completing the active cleaning of the filter element. When cleaning, the power of the ultrasonic probe is 150W, and the ultrasonic frequency is 28kHZ～40KHZ.

In the specific implementation, high-power ultrasound is used to promote the particles in the filter element to leave the filter element, and the electrostatic membrane is used to collect the floating particles, and finally the electrostatic membrane can be cleaned.

According to the method in the GB/T 18801-2015 air purifier standard, the CADR (clean air volume) of the air purifier with the ultrasonic probe filter element and without the ultrasonic probe filter element was tested respectively, and the results obtained are as follows:

Air purifier without ultrasonic probe filter element: CADR value is 777.96, the specific data is as follows in Table 1 and Figure 9.

Table 1

Air purifier with ultrasonic probe: CADR value: 913.90, the specific data is as follows in Table 2 and Figure 10.

Table 2

According to the provisions of the air purifier GB/T 18801-2015 standard, the cumulative purification amount (representing the life of the filter element) indicates the target pollutants of the cumulative purification treatment when the clean air volume (CADR) of the air purifier decays to 50% of the initial value total mass.

When more particles are absorbed in the filter element, the resistance of the filter element will increase and the clean air delivery (CADR) value will decrease. It can be seen from the comparison of the above implementations that the present invention cleans the filter element through high-power ultrasound to remove particulate matter in the filter element, so that the filter element can be used repeatedly and prolong the service life of the filter element.

Claims (5)

1. a recyclable high-efficiency composite ultrasonic filter is characterized in that: comprise housing and be installed in the filter core (4) and fan (6) in housing, fan (6) is placed on the top of housing, filter core ( 4) placed in the lower part of the casing, the side wall of the casing on the side of the fan (6) has an air outlet (8), the side wall of the casing on the side of the filter element (4) has an air inlet (7), and the filter element (4) ) is provided with an ultrasonic transducer (3), and the ultrasonic transducer (3) is placed in the middle of the filter element (4); It also includes an ultrasonic cleaning filter element module installed outside the multi-layer filter element structure. The ultrasonic cleaning filter element module includes an ultrasonic probe (9) and an electrostatic film (10). The ultrasonic probe (9) is arranged on the side of the filter element (4) facing the filter inlet. The electrostatic membrane (10) is arranged on the side of the filter element (4) facing the filter outlet. 2. A recyclable high-efficiency composite ultrasonic filter according to claim 1, characterized in that: said filter core (4) comprises three layers of composite filter paper (1), wave paper (2) and ultrasonic filter The three-layer composite filter paper (1) is arranged in an S-shaped curl, and the adjacent layers of the three-layer composite filter paper (1) after the S-shaped curl are arranged with wave paper (2), and the ultrasonic transducer (3) Place it on the corrugated paper (2) in the middle of the filter element (4). 3. A kind of recyclable high-efficiency composite ultrasonic filter according to claim 2, characterized in that: in the three-layer composite filter paper (1), the first layer is glass fiber, and the second layer is activated carbon fiber , the third layer is glass wool, which is specifically prepared by laminating glass fiber, activated carbon fiber and glass wool. 4. A recyclable high-efficiency composite ultrasonic filter according to claim 2, characterized in that: in the three-layer composite filter paper (1), the glass fiber diameter is 7 μm, and the fiber length is 3 to 10 mm. The proportion of mass is 15%; the diameter of activated carbon fiber is 2.6 μm, the fiber length is 3-10 mm, and the proportion of mass is 30%; the diameter of glass fiber cotton is 0.6 μm, the length of fiber is 3-10 mm, and the proportion of mass is 55%. 5. A kind of recyclable high-efficiency composite ultrasonic filter according to claim 2, characterized in that: said ultrasonic transducer (3) comprises polyurethane (13), piezoelectric ceramic ring (14), nylon screw rod (15), nylon fixing piece (16), rechargeable battery (17), pins (18), connecting wire (19); two nylon fixing pieces (16) are respectively connected to the two ends of the piezoelectric ceramic ring (14), The middle of the two nylon fixing pieces (16) is respectively connected with the two ends of the nylon screw (15) pierced through the piezoelectric ceramic ring (14), and is screwed tightly between the nylon screw (15) and the nylon fixing piece (16). The nylon fixing piece (16) and the piezoelectric ceramic ring (14) form an internally hollow fixed structure; the internally hollow fixed structure is externally covered with polyurethane (13) for protection, and a rechargeable battery (17) is arranged in the internal hollow space, and the rechargeable battery (17) is connected with the external drive circuit through the connecting wire (19), and the two ends of the piezoelectric ceramic ring (14) are connected to two pins (18) respectively, and the pins (18) are connected to the external drive circuit after passing through the polyurethane (13).