BG113506A - Method for purification of gasesous environments at atmospheric pressure, device for implementation of the method and ultrasonic emitter - Google Patents

Abstract

The present inventions are intended for use wherever equipment for air purification at atmospheric pressure is needed, for example for household use, in industry, in confined spaces such as residential and office premises and in specialized rooms or mobile facilities with isolated environments. The method ensures efficient purification of the gaseous environment while avoiding the occurrence of arc discharges. Said method includes the creation of an electromagnetic field between two electrodes (1, 2), wherein pulsating high-voltage and some ultrasonic field are applied at the same time between the electrodes. Furthermore, water is injected by sparging into the gaseous environment of the discharge and the intensity of the electromagnetic field is maintained until the desired level of purification is achieved. The electrodes of the device are a high-voltage pulse electrode (1) and a grounded capturing electrode (2) with at least one ultrasonic emitter (5). Provision is also made for a control unit (12).

Description

METHOD FOR PURIFICATION OF A GAS ENVIRONMENT AT ATMOSPHERIC PRESSURE, DEVICE FOR IMPLEMENTING THE METHOD AND ULTRASOUND EMITTER

FIELD OF ENGINEERING

The atmospheric air purification method, the correspondingly created device for implementing the method and the ultrasonic emitter for it will find application in atmospheric pressure air purification equipment wherever it is needed, including in an urbanized environment, for example for household and technical, in industry , in closed spaces such as residential and office premises and in specialized premises or mobile objects with an isolated environment, where it is necessary to maintain air cleanliness from organic and mechanical particles.

PRIOR ART

From EP 3778033 A1, a device for purifying atmospheric air is known, based on an electrostatic method for collecting dust pollution from the air, as well as a method for its management. The electrostatic method involves the creation of an electromagnetic field by a generating electrode and a trapping electrode located opposite each other. The method proceeds as follows: after switching on the generating electrode, a high potential difference is formed between it and the trapping electrode, producing a corona discharge. In doing so, the dust particles move to the catching electrode, where they are collected and accumulated, achieving an air purification effect. The capturing electrode is capable of changing its position relative to the generating electrode, and its composition of multiple structures, spaced from each other, is also provided for.

Disadvantages of the known solution are that when the method is applied in an urbanized environment, arc discharges may occur and shielding is necessary due to the risk of electric shock. Moreover, at a high concentration of polluting particles, its efficiency is low.

TECHNICAL ESSENCE OF THE INVENTION

The problem to be solved is to ensure a highly efficient purification of the gas medium avoiding the possibility of arc discharges.

The problem is solved with a method for purifying a gaseous medium at atmospheric pressure, which involves creating an electromagnetic field between two electrodes, one of which is a generating electrode and the other is a trapping electrode. According to the invention, a high-voltage impulse voltage with a field intensity of at least 250 V/cm is applied between the electrodes and simultaneously an ultrasonic field is applied, creating a non-self-sustaining gas discharge, while water is sprayed into the gas medium of the discharge, such that the intensity of the electromagnetic field is maintained until the desired purification is achieved.

It is recommended that the high-voltage impulse voltage be in the range of 10 to 30 kV. The ultrasonic field has a frequency of about 1MHz and a power of 5 to 10W.

A device for implementing the method for purifying a gas medium at atmospheric pressure has also been created, which includes a generating electrode and a trapping electrode located opposite each other. According to the invention, the generating electrode is a high-voltage pulse electrode connected to a high-voltage pulse generator, and the capturing electrode is grounded and filled by at least one ultrasonic emitter connected through a matching block to an adjustable direct current source with an output stage to the matching block. The output stage is also connected to a setting generator. The high voltage pulse generator is also connected through the matching block to the setting generator. A differential amplifier and a normalizing amplifier are also provided in parallel to the matching unit, and all of them are connected to a control unit.

It is recommended that the ultrasonic emitters of the catching electrode are located at a distance of at least 50 mm from each other.

It is appropriate that a device measuring the contamination of the gas environment is provided in the control unit.

It is provided, as an option, that the control unit has a display.

The constructed ultrasonic emitter includes a housing with a supported aperture, in which a housing connected to the support houses a package of metal sound reflector with two cylindrical piezoceramic elements fixed thereto, and a half-wave radiating concentrator extending outside the housing and centrally through the aperture. It is a tubular element with walls of a hyperbolic curve, the front end of which is formed as part of a spherical concave surface, at the most concave point of which there is a nozzle opening connected to a centrally and longitudinally located water supply pipe throughout the package and through the housing.

The spherical concave surface at the front end of the half-wave radiating concentrator has a radius of 500mm to 1000mm.

The metallic sound reflector and the half-wave emitting concentrator are made of material with a low coefficient of linear temperature expansion at 20°C a = (9-10). 10 ⁶ /K.

It is appropriate that the material of which the metallic sound reflector and the half-wave emitting concentrator are made is treacherous.

It is good as an option that the material of which the metal sound reflector and the half-wave emitting concentrator are made is titanium alloy.

The advantages of the created method, applied at atmospheric pressure and especially in an urbanized environment, consist in avoiding the occurrence of arc discharges (atmospheric lightning), which is due to the use of a non-independent pulsed gas discharge. The application of pulsed excitation of the gas medium allows to regulate the rate of increase of the concentration of ions in the medium and achieve a balance between shock ionization and recombination at atmospheric pressure in highly efficient purification of gas medium.

BRIEF EXPLANATION OF THE ATTACHED FIGURES fig. 1 is a block diagram of the device for implementing the method according to the invention;

fig. 2 - longitudinal section of an ultrasonic emitter, according to the invention;

fig. 3 - general block diagram of a production version of the device according to the invention.

EXAMPLES OF THE IMPLEMENTATION OF THE INVENTION

According to the invention, a method for purifying a gaseous environment, such as atmospheric air, has been created, which method is based on creating a non-independent pulsed gas discharge at atmospheric pressure. The method includes the following steps:

- in the gas environment, an electromagnetic field with an intensity of at least 250 V/cm is created by applying a high-voltage pulse voltage between electrodes, (one of which is a high-voltage pulse electrode 1, and the second is a trapping electrode 2, which is grounded.).

- simultaneously with the creation of the electromagnetic field, an ultrasonic field is applied to the gas medium, creating a non-self-contained gas discharge, causing ionization of particles 3, commensurate with 0.001 mm and smaller.

- also at the same time, water is injected into the gas medium by means of ultrasonic spraying;

- as the intensity of the electromagnetic field is maintained until the desired purification is achieved.

As a result, the ionized particles entrain other contained fine particles to the trapping electrode, accumulating them.

The method allows to avoid electrical breakdown by applying a quasi-stationary pressure change of the gas medium through the excitation of ultrasonic waves in the ionized region. The frequency of the sound field is matched to the lifetime of the ions formed. By achieving frequency and phase synchronization of the ultrasonic field with the frequency and phase of the electric field, the necessary amplitude of the excitation voltage is reduced.

The field intensity is not less than 250V/cm, realized at a high voltage pulse voltage of 10 to 30kV. In these conditions, the process of collecting the fine particles in the ionized medium takes place. When the described process takes place in a gas environment in a closed volume, the concentration of fine particles steadily decreases. When a contaminated gas environment, for example atmospheric air, from another volume enters through the ionized area, the newly entered amount of air is purified, as a result of the ionization process and the accumulation of fine dust particles, which significantly reduces the mass of newly entered pollutants in the purified volume.

For a sustainable process of the non-self-discharge, a frequency of the ultrasonic field of the order of 1MHz and a power of about 5-10 W is applied.

A device was created to implement the method for purifying a gas medium at atmospheric pressure, which implements the power density of the electromagnetic field and is presented in the block diagram of Fig.1.

The device includes a generating electrode and a trapping electrode located opposite each other. According to the invention, the generating electrode is a high-voltage pulse electrode 1 connected to a high-voltage pulse generator 4. The catching electrode 2 is grounded and filled by at least one ultrasonic emitter 5, connected through a matching unit 6 to an adjustable direct current source 7 with an output stage 8 to the matching unit 6, which output stage 8 is also connected to a setting generator 9. The high-voltage pulse generator 4 is also connected through the matching block 6 to the setting generator 9. A differential amplifier 10 and a normalizing amplifier 11 are also provided and connected in parallel to the matching block 6. All of them are connected to a control unit 12. As a preferred variant, in the control unit 12 is provided a measuring device (not shown) to measure the contamination of the gas environment, which will turn on/off the device for implementing the method. Suitably, the control unit 12 has a display displaying the results of the purification as well as other types of control information.

Typically, the capture electrode 2 is composed of a plurality of ultrasound emitters 5 placed next to each other at a distance of at least 50 mm.

In fig. 2 shows a longitudinal section of an ultrasonic emitter 5, created for implementing the method of purifying a gas medium and for application in the device for its implementation. Regardless of its specific purpose, it can be used in other devices where needed. The ultrasonic emitter 5 includes a housing 13 with an opening 14 with a support 15. In the housing 13, connected to the support 15, there is a package of metal sound reflector 16 with two cylindrical piezoceramic elements 17 fixed thereto and extending outside the housing 13 and centrally through the opening 14 half-wave radiating concentrator 18.

Cylindrical piezoceramic elements 17 with a total size of φ28 mm and a thickness of 20 mm were used in the experiments. Their specific dimensions are determined by the properties of the piezoceramic elements 17 that are used in each specific case and may vary to achieve the required frequency and power of the ultrasonic field indicated above.

The half-wave radiating concentrator 18 is a tubular element with walls on a hyperbolic curve, the front end 19 of which is part of a spherical concave surface, with a radius (R) of 500mm to 1000mm, at the most concave point of which is a nozzle opening 20. This opening of the nozzle 20 is connected to a centrally and longitudinally located throughout the package and through the housing 13 water supply pipe 21, as shown in fig. 2.

The ultrasonic emitter 5 is grounded, and the metal sound reflector 16 and the half-wave emitting concentrator 18 are made of a material with a low coefficient of linear temperature expansion at 20°C — for example, CX = (9-10).10 ^-6 /K. This material can be, for example, covar or titanium alloy.

The water supply pipe 21 is provided for regulating the conductivity of the gas medium of the discharge between the two electrodes 1, 2, which is carried out by spraying a small amount of water into the gas medium. In this way, an advanced technology of electrical atomization and water ionization is implemented. The water pressure is provided by a micropump 22 (fig. 3), which enables the water jet to be supplied in pulses. The micropump is powered by a container of deionized water 23.

The electrical supply of the ultrasonic emitter 5 has a common potential Earth with the high-voltage pulse generator 1 and performs the role of a common anode.

The high-voltage pulse generator 4 creates positive pulses with an amplitude of 30 KV and a frequency of 500 - 1500 kHz, which is adjustable. The distance between the high voltage pulse electrode 1 and the capture electrode 2 (grounded) can vary, and in the experiments it was between 500mm and 800mm. The high-voltage pulse electrode 1 and the matching unit 6 in the present example are connected by a split-transformer, which allows the phase ratio of the electric and ultrasonic fields to be precisely adjusted.

With such a coordinated electric and ultrasonic field, conditions are created for a combination of appropriate pressure in a microvolume and instantaneous intensity of the electric field applied in the gas medium, and an initial instantaneous concentration of current carriers is created, giving rise to an ion-electron current. The ionization of the gas medium to a hot arc discharge is avoided by terminating the electrical impact, which is carried out through the control unit 12. Simultaneously, the impact of the ultrasonic field is also terminated. The environment recombines. With a delay determined by the instantaneous value of the current between the electrodes, the next process of impact and ionization begins. The process lends itself to steady progress and is regulated to quasi-stationarity.

APPLICATION OF THE INVENTION

It is envisaged that the invention will most often be applied in practice to purify the air of residential, office and other purposed spaces from organic and mechanical particles. In the most commonly envisioned application, a frame is fabricated enclosing a column of the high voltage pulse electrode and an opposite column of the trapping electrode, in which frame the elements of the method application device are embedded. The frame is located in an open environment or in a room or, for example, in a suitable opening bordering the outside air or in an opening between two rooms. The high-voltage pulse electrode 1 and the capture electrode 2 through the control unit 12 are connected to a corresponding power supply, as indicated above.

When the device is turned on, the atmospheric air purification method is carried out through its elements, and all processes take place automatically during the operation of the device. Accumulated fine particles should be removed when necessary by any of the generally accepted methods of vacuuming, washing, etc.

During the experiments explained above, the following characteristics were achieved: length of the two electrodes - 650mm, distance between the electrodes up to 800mm. For safe operation, the high-voltage pulse electrode 1 and the capture electrode 2 are preferably located in shielding channels, for example with a cross-section of 100x100mm (not shown). In practice, the device created for the application of the method works as an ionization channel in a volume of gaseous medium - atmosphere. It is appropriate, depending on the volume in which the purification method and the device are used, to place the number of devices corresponding to the volume, arranged in a plane with the necessary calculable length. The distance between them is determined experimentally so as to guarantee the purification of the volume determined for this.

The electrical consumption of one channel is about 220 W.

Claims (12)

1. A method for purifying a gaseous environment at atmospheric pressure, comprising creating an electromagnetic field between two electrodes, one of which is a generating electrode and the other is a trapping electrode, characterized in that a high-voltage pulse voltage of field intensity is applied between the electrodes a minimum of 250 V/cm and simultaneously applying an ultrasonic field creating a non-self-contained gas discharge, whereby water is sprayed into the gas medium of the discharge, and the intensity of the electromagnetic field is maintained until the desired purification is achieved. 2. Method according to claim 1, characterized in that the high-voltage pulse voltage has values from 10 to 30 kV. 3. Method according to claim 1 or 2, characterized in that the ultrasonic field has a frequency of the order of 1 MHz and a power of 5 to 10 W. 4. A device for implementing the method for purifying a gas environment at atmospheric pressure, including a generating electrode and a trapping electrode located opposite each other, characterized in that the generating electrode is a high-voltage pulse electrode (1) connected to a high-voltage pulse generator (4) and the capture electrode (2) is grounded and filled by at least one ultrasonic emitter (5) connected through a matching unit (6) to an adjustable direct current source (7) with an output stage (8) to the matching unit (6) ), which output stage (8) is also connected to a setting generator (9), where the high-voltage pulse generator (4) is also connected through the matching block (6) to the setting generator (9), and to the matching block (6) are a differential amplifier (10) and a normalizing amplifier (11) are provided and connected in parallel, and all of them are connected to a control unit (12). 5. Device according to claim 4, characterized in that the ultrasonic emitters (5) of the capturing electrode (2) are located at a distance from each other of at least 50 mm. 6. Device according to claim 4 or 5, characterized in that the control unit (12) is provided to measure the contamination of the gas medium REG. 7. Device according to one of claims 4 to 6, characterized in that the control unit (12) has a display. 8. Ultrasonic emitter, characterized in that it includes a housing (13) with an opening (14) with a support (15), in which a housing (13) connected to the support (15) houses a package of metal sound reflector ( 16) with two cylindrical piezoceramic elements (17) fixed to it and extending outside the housing (13) and centrally through the hole (14) a half-wave radiating concentrator (18), being a tubular element with walls on a hyperbolic curve, the front end of which (19) is a part of a spherical concave surface, in the most concave point of which there is a nozzle opening (20), connected to a water supply pipe (21) located centrally and longitudinally throughout the package and through the housing (13). 9. Ultrasonic emitter according to claim 8, characterized in that the spherical concave surface of the front end (19) of the half-wave emitting concentrator (18) has a radius (R) of 500mm to 1000mm. 10. Ultrasonic emitter according to one of claims 8 or 9, characterized in that the metal sound reflector 16 and the half-wave emitting concentrator 18 are made of a material with a low coefficient of linear temperature expansion at 20°C a = (9-10 ).10 ^-6 /K. 11. An ultrasonic emitter according to claim 10, characterized in that the material from which the metal sound reflector 16 and the half-wave emitting concentrator 18 are made is metal. 12. Ultrasonic emitter, according to claim 10, characterized in that the material from which the metal sound reflector 16 and the half-wave emitting concentrator 18 are made is titanium alloy.