RU2200633C1 - Air cleaning method - Google Patents

Abstract

FIELD: gas treatment. SUBSTANCE: method of cleaning air allows oxidation of organic impurities and more efficient removal of tobacco smoke from rooms owing to using following multistage treatment: preliminarily filtration of incoming air flow through air sol filter, exposing to electric discharge, severe oxidative ozone-treatment with ozone concentration 40-200 mg/cu. m., electrical filtration, extra ozone catalytic destruction, and absorption of ozonization and ionization products. To destroy extra ozone and more fine air cleaning, air is passed through (i) ozone-destruction catalyst containing oxide and/or hydroxide of metal selected from iron, manganese, copper, nickel, and palladium and (ii) ozonization product absorber containing basically reacting fibrous material. EFFECT: enhanced air cleaning efficiency. 3 cl, 2 dwg, 1 tbl

Description

 The invention relates to the field of technical means for cleaning, disinfection, sterilization and deodorization of air using physical phenomena, in particular electrostatic filtration and ionization, using catalytic and sorbing materials. The invention can be used to purify air in domestic, medical and industrial premises from fine dust, microscopic fungi, for biocidal air treatment, remove unpleasant odors, tobacco smoke, detoxify harmful organic substances that are products of human metabolism or stand out from modern building decoration materials in its habitat.

 A known method of purification of gases in electrostatic precipitators, including pre-filtering the incoming stream and introducing into it a gaseous chemical reagent - sulfur oxide (II) or freon, corona treatment and electrostatic deposition of impurities on the electrodes [DE 1457058 A, 1970].

 There is also a method of purification of gases in electrostatic precipitators, including preliminary filtration of the incoming stream, corona treatment, the introduction of a chemical reagent - vapors of hydrocarbons or freons in an amount of 0.001-0.01 vol. % and electrostatic deposition of impurities on the electrodes [RU 2121881 C1, 1998].

 There is also known a method of air purification in a dual-zone electrostatic precipitator, including preliminary filtering of the incoming air flow, treatment with corona discharge and treatment with ozone, incidentally formed in the discharge, electrostatic filtration by absorbing excess ozone and toxic gases with a carbon sorbent and ionization [US 5656063 FB, 1997]. The method allows to capture household aerosols with an efficiency of 91-98% and purify the air of carbon oxides and nitrogen.

 The disadvantage of this method is the high noise level resulting from pumping air through a layer of carbon granules of an ozone absorber and toxic gases, which has significant aerodynamic resistance, and the need for periodic replacement.

 The technical problem to which the present invention is directed is to reduce noise, simplify filter maintenance and intensify the process of purifying air from harmful substances using ozone oxidation without exceeding the maximum permissible concentration of residual ozone in the stream of purified gas.

The problem is solved in that in a method of air purification, including pre-filtering the incoming air flow through an aerosol filter, electric discharge treatment, ozone treatment, electrostatic filtration and ionization, according to the invention, ozone treatment is carried out at an ozone concentration of 40-200 mg / m ³ and after electrostatic filtration, air is additionally passed through an ozonation product absorber and an ozone decomposition catalyst. The absorption of ozonation products is carried out using breathable mats made of chemisorption fibers with basic properties or impregnated with salts and other substances with basic properties. The catalyst for the decomposition of ozone are oxides and / or hydroxides of metals selected from the group of iron, manganese, copper, nickel, palladium. To carry out the ozone decomposition stage, an air stream containing ozone is passed through a volumetric mesh with a nominal density of 20-200 kg / m ³ from a metal wire with a diameter of 0.1-0.8 mm, with a linear flow rate of 0.2-2.0 m / s, providing contact time with the catalyst from 0.01 to 0.5 s.

 Resistance to the air flow of the decomposition catalyst of ozone and an absorber of ozonation products can be 30-300 Pa depending on their thickness. The procedure for treating air on ozone decomposition catalysts and ozonation product absorbers may vary depending on the design of the device implementing this air purification method.

 The invention is illustrated by an air purification scheme, a graph and an example.

 Figure 1. Air purification scheme.

 1. - Filtration of the incoming air flow through the aerosol filter.

 2. - Processing of air flow by electric (corona) discharge.

 3. - Electrostatic filtration and ozone treatment.

 4. - Ozone treatment.

 5. - Decomposition of excess ozone.

 6. - Absorption of ozonation products.

 7. - Ionization of purified air.

 Air is sucked through the coarse aerosol filter and freed of particles up to 5 μm in size with an efficiency of 90% (1), then air enters the corona discharge zone (2), where small particles of impurities receive an electric discharge and are deposited on a moving (cleaned) electrode ( 3), ozone is formed in the corona discharge zone, part of the organic substances under the action of ozone is oxidized to products of an acidic nature or carbon monoxide (IV) and water (4), excess ozone decomposes on the catalyst (5), substances that have or acquire during ozonation is acidic in nature, retained by a fiber absorber of ozonation products (6), the cleaned air is ionized to hygiene standards at the finishing stage of processing (7) and is discharged into the room.

или карбоксильного катионообменного волокна в К- или Na-форме с емкостью 5-6 мг-экв/г и боковыми группами строения:

или вискозного, углеродного, полиамидного или аримидного волокна с пропиткой из солей сильных оснований и слабых кислот.The ozonation product absorber may take the form of a breathable mat of a mixture of polypropylene fiber and an ion exchange fiber with the main properties, for example, an anion exchange fiber with a capacity of 5-7 mEq / g and side groups of N- (2-aminoethyl) imidazoline. The structure of the side groups has the form

or a carboxyl cation exchange fiber in K- or Na-form with a capacity of 5-6 mEq / g and side groups of the structure:

or viscose, carbon, polyamide or arimide fibers impregnated from salts of strong bases and weak acids.

 Example.

They clean the air of a smoking room with a volume of 100 m ³ using a filtering device pumping air with a capacity of 20 m ³ / h. Air containing dust particles, tobacco smoke, and organic matter impurities is passed through a filter cloth in series with a linear velocity of 0.3 m / s, a dual-zone electrostatic precipitator containing a corona discharge generator and an electrostatic precipitator with plates parallel to the air stream in which ozone is generated in an amount of 100-200 mg / m ^3, then through absorber ozonization products made of a breathable nonwoven mat of a mixture of polypropylene fibers and ion exchange fibers with the basic properties E polyamide fiber modified with carboxyl groups in the Na-form and through the volume mesh of steel wire coated with ozone decomposition catalyst comprising oxides and hydroxides of manganese, iron and copper. The contact time with the ozone decomposition catalyst varies by changing the thickness of the catalyst network layer from 0.01 to 0.1 s. The current ozone concentration in the exhaust air stream is controlled by a chemiluminescent gas analyzer of ozone modes. 3-02-P1 and is compared with the ozone concentration in the outlet stream passing through the ozone decomposition catalyst. In parallel, the concentration of smoke in the room is measured. The data are shown in tables and in the figure (figure 2).

Claims (3)

1. The method of air purification, including pre-filtering the incoming air flow through an aerosol filter, processing by electric discharge, treatment with ozone, electrostatic filtration and ionization, characterized in that the treatment with ozone is carried out at an ozone concentration of 40-200 mg / m ³ and after electrostatic filtration air is additionally passed through an absorber of ozonation products and an ozone decomposition catalyst.  2. The method of air purification according to claim 1, characterized in that the air is passed through an ozone decomposition catalyst containing an oxide and / or hydroxide of a metal selected from the group iron, manganese, copper, nickel, palladium, and an ozonation product absorber containing anion exchange fiber a material or material containing carboxyl groups in Na or K form.  3. The method of air purification according to claim 1, characterized in that the air is passed through an ozone decomposition catalyst with a linear flow rate of 0.2-2.0 m / s and a contact time with the catalyst of 0.01-0.5 s.

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