MXPA01008973A - Method and process for separating materials in the form of particles and/or drops from a gas flow - Google Patents

Abstract

The invention relates to a method and device for separating materials in the form of particles and/or drops from a gas flow, in which method the gas flow is directed through a collection chamber the outer walls of which are grounded, and in which high tension is directed to the ion yield tips arranged in the collection chamber, thus providing an ion flow from the ion yield tips towards the collection surfaces, separating the desired materials from the gas flow. It is characteristic of the invention that the collection surfaces conducting electricity are electrically insulated from the outer casings;and that high tension with the opposite sign of direct voltage as the high tension directed to the ion yield tips is directed to thecollection surfaces. According to an embodiment of the invention the electrical insulation is made of ABS, and the surface conducting electricity comprises a thin chrome layer arranged on the insulation layer.

Description

METHOD AND PROCESS FOR SEPARATING MATERIALS IN THE FORM OF PARTICLES AND / OR DROPS FROM GASEOUS FLOW The present invention relates to a method for separating materials in the form of particles and / or droplets from a gaseous flow, in which method the gaseous flow is directed through a collection chamber, the outer walls of which are connected to earth; and in which method the high voltage is directed to the ion producing tips placed in the collection chamber so that an ion beam that separates the desired materials from the gas flow is achieved through the walls that function as collection surfaces. The invention also relates to a device for applying said method. Currently, filters, dust extractors or electrical methods are used, such as electric filters or an ion blowing method in gas purification systems and to separate particles from a gaseous flow. When using filters, the velocity of the flowing gas must be kept low in the fabric or metal filters, because the increase in velocity generates strong air resistance. Also, the resolution of the filters decreases along with the increase in speed. For example with microfilters, the velocity of the gas flow is initially less than 0.5 m / second. Furthermore, it is not possible to achieve good cleaning results with the known techniques when nano-sized particles are involved (ie particles whose diameter is from one nanometer to a dozen nanometers). The operation of the dust extractors is based on the decrease in the velocity of the gas flow so that the heavy particles in the gaseous flow fall inside the collection organ. Therefore, dust extractors are applicable to separate heavy particles, because they possess a high descending velocity. In electric filters, the separation of the particles from the gas is carried out on collection plates or towards the interior surfaces of pipes. The velocity of the gas flowing in electric filters must generally be below 1.0 m / second, with the manufacturers' specifications being approximately 0.3 - 0.5 m / second. The reason for a low gas flow velocity is that a higher flow velocity releases the accumulated particles on plates, causing the resolution to decrease considerably. The operation of electric filters is based on the electrostatic charge of the particles. However, it is not possible to electrically charge the particles in the nanoscale category. In addition, not all materials are electrically charged, for example stainless steel. In electrical filters, the low velocity of the gas flow must be used due to the cleaning stage of the collection plates. When the plates are cleaned, a blow is directed towards the plates, releasing the collected particulate material. The intention is that only the smallest possible amount of particulate material released from the plates during the purification step would return to the flowing gas. With a low gas flow rate it is possible to achieve tolerable particle passages. The known technique is described below with reference to the accompanying drawings, in which Figure 1 shows the equipment used in the ionic blowing method according to the known technique; and Figure 2 shows a method of the known art for purifying the gas with the ionic blowing method. In figure 1, a device for purifying gas according to the known technique is shown. The equipment shown comprises an inlet 1 for the incoming gas to be purified, an outlet 2 for the purified gas, a voltage cable 3, an insulator 4, a collection chamber connected to earth 5, an energized holding bar 6, comprising several ion producing tips 7, a vibrator arrangement 9 for the collected particles and a voltage source 10. In figure 1, for example, the air entering a building or the air that is recycled is directed towards the collection chamber 5 for purification. The air to be purified enters the collection chamber 5 through the entrance 1, goes up and after the purification, exits through the exit 2. The purification is carried out by ionization of the gas with the producing tips of ions 7 attached to the energized holding bar 6 and connected to the voltage source 10 by means of the voltage cable 3, the voltage source 10 which is capable of directing high positive or negative voltage (as in the figure) towards the clamping bar 6. In other words, an ionic blowing is directed towards the gas either positive or negative, and the ions and charged particles as well as the uncharged particles are transported towards the collecting surface 5 together with the ion blowing. The ion producing tips 7 are directed towards the ground collecting chamber 5 which acts as the collecting surface for the particles. The collection chamber 5 is isolated from the energized parts 6, 7 by the insulator 4. A voltage of approximately 70-150kV is fed to the ion producing tips 7 and the distance thereof from the collection chamber 5 is arranged to generate a conical ion blowing effect so that the charged and uncharged particles are brought to the wall of the collection chamber 5 and adhere to it due to the difference in charge between the charge 0 of the wall of the collection chamber 5 and the load of ionic blowing. The distance between the ion producing tips and the collection wall 5 is commonly 200-800 mm. Figure 1 further shows the vibrator arrangement 8 for purifying the collection chamber 5 by vibration. The vibrator arrangement is designed so as to vibrate the chamber, the collected particles fall and exit through the recovery channel 9. The collected substance can also be washed with water. The ion blowing method is characterized by a corona effect achieved by the high voltage so that the voltage intensity is increased so much that an ion blowing effect is generated from the ion producing tips for the desired grounded structure. A number of ion producing tips are required which are calculated separately for each gas separation application. The ionic blowing method has been described more closely, for example, in the patent publication EP-424335. Figure 2 presents a solution for purifying gas in a collection chamber with the aid of an ionic blowing method according to the known technique. The figure shows an outlet 2 for the purified gas, a grounded collecting chamber 5 and an energized holding bar 6, comprising several ion-producing tips 7. In addition, the figure shows the ionic blowing 11, the particle accumulations 12, 13 and 14 in the collection chamber 5 and the gaseous flow 15. The solutions in figures 1 and 2 are characterized by the position of the ion producing tips 7 in the rings 22, with the help of which they are reduced the distance between the ion-producing tips and the collection surface. Especially in the industry, in which several kilograms of substance have to be separated from large gaseous flows in a second, the ion blowing equipment is relatively large, due specifically to the high voltage used. In several industrial li it is difficult to find the necessary space for the equipment in the ionic blowing method. The object of the present invention is to provide a method and a device, with which materials in the form of particles and / or droplets can be separated from the gaseous flow, and the demand for dust can be radically reduced and the separation methods can be improved for the accumulated particle material on the collection plates. In the method of the invention, the impurities are separated from the gaseous flow through a counter-phase method, which is characterized in that the collecting surfaces that conduct electricity are electrically isolated from the external covers and that the high voltage is directed to the collection surfaces, the high voltage that has the opposite sign of direct voltage as the high voltage directed to the ion producing tips In comparison with the known ionic blowing method described above, the difference is that the method of the invention has an electric field between the tips ion producers and the walls of the collection chamber as additional energy. When the high voltage is directed to the collection surfaces, an electric field is generated in front of the collection surface, extracting the ions with opposite sign and charged particles towards the electrical charge opposite to the collection surface. With the push-pull method, better separation is achieved so that the ion-producing tips do not need to be placed towards the rings, although they may be attached to the clamping bar. Through the use of the method of the invention, the operating voltage decreases to 1/3 -% in relation to the known art method shown in Figure 2. At the same time, the costs to achieve the same amount of air and the same level of purity, even up to 1/3. A further object of the invention is to provide a device for carrying out the method of the invention described above. It is characteristic of the device of the invention that the collection surfaces that conduct electricity are electrically isolated from the external covers and that, the high voltage is directed from the voltage source towards the collection surfaces, the high voltage having the opposite sign of the Direct voltage as the high voltage directed to the ion producing tips. In one embodiment of the invention, a gap is provided between the electrical insulation and the outer cover. The invention will now be described in greater detail, with reference to the accompanying drawings in which: Figure 1 shows a known art equipment used in the ionic blowing method; Figure 2 shows a method of the known art for purifying gas with the aid of the ionic blowing method; and Figure 3 shows the structure and principle of operation of a separation device according to the invention.

Figures 1 and 2 have been described. The solution of the invention is described below, with reference to Figure 3 showing one embodiment of the invention. Figure 3 shows a separation device of the invention, its structure and principle of operation. The figure shows an outlet 2 for the purified gas, an external cover connected to earth and an energized holding bar 6 comprising several ion producing tips 7. Additionally, the master figure ionic beams 11 and a gaseous flow 15. In addition, the figure shows an air space placed between the outer cover 5 of the collection chamber and the electrical insulating layer 17, and a surface 18 that conducts electricity on the inner surface of the electrical insulating layer 17. The electrical insulating layer 17 is attached to the outer cover 5 with the help of fasteners 21. The voltage with the opposite sign of the direct voltage, positive in the figure, as the high voltage directed to the ion producing tips 7 (negative in the figure) is directed to the surface 18 that conducts electricity. Therefore, the voltages are opposite, ie positive for the ion producing tips 7 and negative for the surface 18 that conducts electricity, or negative for the tips that produce ions and positive for the surface that conducts electricity. The voltage of the ion producing tips 7 is substantially equal to that of the collecting surface, ie the surface 18 that conducts electricity, although it is also possible to use voltages of different magnitude. The advantage of equal voltages is the simplest structure of high voltage centers. They have also achieved better purification results with equal voltages. Figure 3 further shows a vacuum 19 charged with a positive electric field in front of the surface 18 that conducts electricity; the hollow 19 is loaded with a positive sign, because the positive high voltage is directed towards the surface 18. As the charge of the surface 18 that conducts the electricity is reversed, that is, in this case it is negative, the accumulated substance is released and falls into the recovery channel (reference number 9 in Figure 1) at the bottom of the collection chamber, as the electric field releases the particles. Therefore, the vibration arrangements in the device of the invention are not necessary. However, they can be used when desired. The most common purification of the collecting surfaces is carried out automatically by washing with liquid, it being then possible to program the purification interval and the purification time desired. In the washing with liquid, the purification liquid is fed from the injection tube 20, and as it flows along the collection surface 18, the liquid removes the accumulated particles from the surface 18. When desired, it is also possible use, for example, disinfectant in the purification agent. As shown above, by changing the load of the conductive collecting surfaces 18, the accumulated substance is caused to remain on the surfaces or to separate from them. The charges used in the device are about 10-60kV, preferably about 30-40kV and the current about 0.05-5.0mA, preferably about 0.1-3.0mA. The electrical insulation 17 placed on the energized collection surface 18 and shown in Figure 3 can be glass, plastic or some other similar substance that isolates the high voltage, preferably the insulator 17 is acrylic-nitrile-butadiene-styrene (ABS) . In addition, the electrically conductive flat layer shown in Figure 3 and placed on the electrical insulator 17 is made of metal, such as a thin metal plate or film in the insulating layer, or of a wire mesh placed partially or totally on the insulating layer or inside it. It is especially preferable that the electricity conducting member comprises a layer of hard chromium placed on the insulating layer and provided by vacuum evaporation. Other metallization methods can also be used, in addition to metal film adhesion and other fastening methods. With the method according to the invention, each of the minute solid particles in the form of particles and droplets of liquid can be efficiently separated from the gaseous flow. The treatment of the gas takes place in chambers, tunnels or tubular structures, in which the gas is directed towards the ion beam. The ion beam generates an impulsive force for the material collected against the collection surface and simultaneously electrically charges the particles with capacitance. The electric field with opposite sign provided on the collection surface provides the particles or materials in the form of drops with a tensile force on the collection surface. Therefore, the impulsive force of the ion beam and the tensile force of the electric field are available to remove the particles from the gaseous flow. In the method according to the invention, the ion production can be of a type that produces ions either negative or positive.

The ion blowing equipment according to the invention can be installed, for example, in genetic research laboratories in which particles with a diameter of at least 1 nm can be released from strains of DNA. In these laboratories, traditional electric filters do not work satisfactorily, since they can not load nano-sized particles. The purification of the gas according to the invention is usually carried out in an air purification, also being used very appropriately, for example, in isolation rooms in hospitals, operating rooms, factories that manufacture microcircuits, and the air inlet in rooms in which biological weapons have to be repelled. Therefore, the use of the invention can comprise all the rooms and the purification of the inlet air and the outlet air.

The purification of air in the particle size and droplet size of 1 nm -100,000 nm is possible with the method of the invention, as well as the continuous purification of the air during the washing of the collection surface when the voltage of the collecting surface it can be eliminated, if the washing mode requires too much liquid. The method according to the invention can also be applied in various purification equipments for gas and combustion gas, for example in purification equipment based on filters, powder extract / s, electric filters, material separators or the method of ionic blowing. The standard models of the method are suitable for air purification of rooms in houses and offices. With the method according to the invention, the separation can be carried out for particles with a diameter from one nanometer to particles with a size of hundreds of micrometers. Neither the specific gravity nor the electrical capacitance of the particles is an obstacle to separation. The gas can be purified by the part of different particle sizes up to pure gases. It is obvious that one skilled in the art that the method and device for separating materials in the form of particles and / or droplets from a gaseous flow are not limited to the example described above, but are based on the following claims

Claims (12)

1. Method for separating materials in the form of particles and / or droplets from a gaseous flow, especially particles and / or droplets with a diameter from one nanometer to a few dozen nanometers, in which method the gas flow is directed through a chamber of collecting the outer walls of which are connected to earth, and in which method the high voltage is directed towards the ion-producing tips placed in the collection chambers so an ion beam from the ion-producing tips separates the materials desired from the gaseous flow, is achieved towards the walls function as collection surfaces, characterized in the collection surfaces conduct electricity are electrically isolated from the external covers substantially over the entire area of the collection surfaces and the high voltage with opposite sign of the direct voltage as the high voltage directed to the tips p Ion conductors are directed to the collecting surfaces.

2. The method according to claim 1, characterized in a voltage of 10-60 kV, preferably 30-40 kV is used in the method, and a current of 0.05-5.0 mA, preferably 0.1-3.0 mA, is used. .

The method according to claim 1 or 2, characterized in the electrical charge of the electricity conducting surface is changed such the substance accumulated on the walls is caused to separate from the wall surfaces.

4. The method according to claim 1 or 2, characterized in the substance accumulated in the walls is removed by washing the collection surfaces with liquid.

5. Device for separating materials in the form of particles and / or droplets from a gaseous flow, especially particles and / or droplets the diameter of which varies from a nanometer to a few dozen nanometers, the device comprising an inlet for incoming air to be purified; a collection chamber, the outer walls of which are connected to earth; an outlet for the purified gas; a voltage source with actuators; an energized holding element to which ion-producing tips have been placed and in which device the high voltage is directed to the ion-producing tips by providing an ion beam from the ionic producing tips towards the collecting surface characterized in the collecting surfaces conduct electricity are electrically isolated from the external covers; and the high voltage with the opposite sign of the direct voltage as the high voltage directed to the ion producing points is directed from the voltage source towards the collection surfaces.

Device according to claim 5, characterized in there is a gap provided between the electrical insulation and the external cover.

The device according to claim 5, characterized in the electrical insulation of the collection surfaces is glass, plastic or similar material isolates the high voltage.

Device according to one of claims 5 - 7, characterized in the insulation is acrylic-nitrile-butadiene-styrene (ABS).

Device according to one of claims 5 - 8, characterized in the flat surface conducts electricity is made of metal.

Device according to one of the claims 5-9, characterized in the electricity conducting surface is a layer, such as a wire mesh, which conducts electricity and is placed totally or partially on the inner surface of the insulating layer or inside of the insulating layer.

Device according to one of claims 5 - 10, characterized in the electricity conducting surface is a thin metallic layer, preferably a thin chromium layer.

12. Device according to claim 11, characterized in the thin metallic layer is provided in the insulator by vacuum evaporation metallization.