RU2709032C1 - Disinfection device - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to disinfectology and sanitation, and is intended for disinfection and sterilization of hands or surfaces. Device for disinfection includes a tank with a working solution, a pump with an ejector connected to the discharge chamber, wherein the pump with the ejector form a circulation circuit for multiple activation of the working solution with wet air treated with plasma. Discharge chamber is a chamber with coaxial conductive cylinders connected to a high-voltage alternating voltage source and separated by a dielectric barrier, or with parallel tubes of dielectric, inside which there are conducting rods, connected to high-voltage source of alternating voltage, or with parallel conducting plates connected to high-voltage alternating voltage source, separated by dielectric layer, or with dielectric tube, outside of which conductive cylinder is located, and inside conductive spiral connected to high-voltage source of alternating voltage, or with two electrodes connected to high-voltage alternating source, placed inside dielectric shell.

EFFECT: invention provides an increase in the efficiency of the process of producing a disinfectant.

1 cl, 6 dwg

Description

The invention relates to medicine, namely to disinfection and sanitation, and is intended for disinfection and sterilization of hands or surfaces.

It is known that water treated with low-temperature plasma acquires disinfectant properties [Rohit Thirumdasa, Anjinelyulu Kothakotab, Uday Annapurec, Plasma activated water (PAW): Chemistry, physico-chemical properties, applications in food and agriculture | DOI: 10.1016 / j.tifs.2018.05.007]. A serious drawback of existing methods and devices for treating aqueous solutions with low-temperature plasma is the long exposure time, reaching several hours per ml. The disinfecting properties of water by treated plasma are apparently associated with the formation of OH radicals in the discharge, which in turn react with nitrogen in the air and form long-lived radicals. A long exposure time is associated with a small cross section of the reaction for the dissociation of a water molecule by free electrons and the highest chemical reactivity of OH radicals.

Also known is a method and device for significantly improving the disinfecting properties of hydrogen peroxide in a plasma discharge (US 5785934 A, 07.28.1998). The energy required by the dissociation electron of a hydrogen peroxide molecule is significantly lower than water - 0.6 eV versus 8.8 eV. However, to achieve the desired effect, high concentrations of hydrogen peroxide of about 8% are required, which significantly limits the application of this method.

US 7008592 B2, March 7, 2006 (SteraMist instrument www.tomimist.com) describes a fluid activation system where the starting materials are hydrogen peroxide, peracetic acid, sodium percarbonate and glutaraldehyde. Both patents emphasize sterilization with OH radicals.

The presented invention offers a new approach for processing an aqueous solution with low-temperature plasma, significantly accelerating the reaction for the formation of long-lived nitrogen compounds.

The objective of the invention is to expand the arsenal of technical means.

The technical result of the claimed invention is to increase the efficiency of the process of producing a disinfectant.

The technical result is achieved due to the fact that the device for disinfection includes a tank with a working solution, a pump with an ejector connected to it, connected to a discharge chamber, while a pump with an ejector forms a circulation circuit for repeatedly activating the working solution with moist air treated with plasma, and a discharge the camera is a camera with coaxial conductive cylinders connected to a high-voltage source of alternating voltage and separated by a dielectric barrier, or parallel and tubes made of dielectric, inside which there are conductive rods connected to a high-voltage source of alternating voltage, or with parallel conductive plates connected to a high-voltage source of alternating voltage, separated by a layer of dielectric, or with a tube of dielectric, outside of which there is a conductive cylinder, and inside conductive a spiral connected to a high voltage source of alternating voltage, or with two electrodes connected to a high voltage alternating source, eschennymi inside a dielectric sheath.

The claimed invention is illustrated by drawings.

FIG. 1 is a diagram of a device for disinfection.

FIG. 2 is a diagram of a variant of a discharge chamber with coaxial conductive cylinders connected to a high voltage source of alternating voltage and separated by a dielectric barrier.

FIG. 3 is a diagram of a variant of a discharge chamber with parallel tubes of dielectric, inside which are conductive rods connected to a high-voltage source of alternating voltage.

FIG. 4 is a diagram of an embodiment of a discharge chamber with parallel conductive plates connected to a high voltage AC voltage source, separated by a dielectric layer.

FIG. 5 is a diagram of a variant of a discharge chamber with a dielectric tube, on the outside of which there is a conductive cylinder, and inside a conductive spiral, connected to a high-voltage source of alternating voltage.

FIG. 6 is a diagram of a variant of a discharge chamber with two electrodes connected to a high-voltage alternating source placed inside a dielectric sheath.

The device for disinfection contains:

1 - tank;

2 - pump;

3 - ejector;

4 - the first discharge chamber;

5 - an ultrasonic evaporator or nozzle with a pump;

6 - second discharge chamber;

7 - coaxial conductive cylinders;

8 - dielectric barrier;

9 - dielectric tubes;

10 - conductive rods;

11 - conductive plates;

12 - dielectric layers;

13 - a tube of dielectric;

14 - conductive cylinder;

15 - conductive spiral;

16 - electrodes;

17 - dielectric sheath.

The device (Fig. 1) consists of a tank 1 with a working solution, a pump 2, an ejector 3 and a first discharge chamber 4, an ultrasonic evaporator or nozzle with a pump 5, and a second discharge chamber 6. Water or a weak solution of hydrogen peroxide are used as a working solution ( ~ 0.3-0.5%). The working solution from the tank 1 is supplied by means of a pump 2 to the circulation circuit. An ejector 3 connected to the discharge chamber 4 is connected to the circuit. The ejector creates a pressure difference, thereby providing a suction of moist air into the discharge chamber. Wet air passes through the discharge chamber 4 and mixes with the circulating water.

The following design options for the discharge chamber 4 are possible:

- coaxial - coaxial conductive cylinders connected to a high-voltage source of alternating voltage are separated by a dielectric barrier (Fig. 2);

- cylindrical - parallel tubes of dielectric inside which are conductive rods connected to a high voltage source of alternating voltage (Fig. 3);

- plane-parallel - parallel conductive plates connected to a high-voltage source of alternating voltage are separated by a dielectric layer (Fig. 4).

- spiral - a tube of dielectric, outside of which there is a conductive cylinder, and inside a conductive spiral, connected to a high-voltage source of alternating voltage (Fig. 5).

- axial - two electrodes connected to a high-voltage alternating source, placed inside the dielectric sheath (Fig. 6).

The claimed technical result is achieved in all embodiments of the discharge chamber 4.

Inside the tank 1, the air humidity reaches up to 90-95%, high humidity in the tank is a critical parameter of the device.

Water in the process of operation of the device repeatedly passes through the circulation circuit of the pump - ejector 3, saturated with active particles of moist air treated with plasma.

Water is activated in the device for several minutes and can later be used as a disinfectant.

One of the ways to significantly increase the disinfecting properties of the resulting solution is to re-treat it with a plasma discharge directly at the outlet of the device in the second discharge chamber 6. Activated water is evaporated using an ultrasonic humidifier or fed to a spray nozzle 5. The resulting cold mist or fine droplets of water fall into discharge chamber 6 similar to FIG. 2-4, located directly at the outlet of the reactor and re-processed with cold plasma.

A detailed explanation of the plasma-chemical processes of the conversion of water into a disinfecting agent is given below.

The pulse voltage applied to the electrodes separated by a dielectric barrier forms an electron avalanche with the formation of a large number of discharge channels (streamers). Free accumulate on the surface of the dielectric and induce a field directed against the field from the electrodes and, after some time, stop the avalanche. Then, after changing the polarity of the voltage across the electrodes, the accumulated charge again induces an avalanche and the process of formation of avalanches is repeated. As a result, the barrier dielectric discharge is a set of microstrimers filling the entire discharge gap.

The free electrons of avalanches have an energy of about 1-8 eV and initiate a chain of chemical reactions in the air, resulting in the formation of active forms of nitrogen and oxygen

N ₂ + e → 2N + e

O ₂ + e → 2O + e

O + O ₂ + M → O ₃ + e

N + O ₂ → NO + O

NO + O ₃ → NO ₂ + O

NO ₂ + N → N ₂ O + O

The appearance of O ₂ ^- superoxide in a plasma discharge, the mechanism of plasma formation in which has not yet been fully studied, was also shown [Julie Chauvin, Florian Mohammed Yousfi, Patricia Vicendo & Nofel Merbahi, Analysis of reactive oxygen and nitrogen species generated in three liquid media by low temperature helium plasma jet, Scientific Reports | 7: 4562 | DOI: 10.1038 / s41598-017-04650-4].

The bactericidal action of the barrier dielectric discharge, which is apparently associated with the indication of oxide stress in bacteria and eukaryotic cells, is well known [David B. Graves, Mechanisms of Plasma Therapeutics, GEC-68 / ICRP-9 / SPP-33]. A special role in the interaction of plasma with biological objects is played by nitrogen oxides, the accumulation of which protects eukaryotic cells from reactive oxygen species and enhances their effect on prokaryotes [Wink, D.A. Nitric oxide protects against cellular damage and cytotoxicityfromreactiveoxygenspecies / D.A. Winkj I. Hanbauer, M.C. Krishnaetal. // ProcNatlAcadSciUSA. - 1993. - Vol. 90. - P. 9813-9817].

In the presence of water vapor in a plasma discharge, a small amount of nitric acid is synthesized

NO ₂ + O ₃ → NO ₃ + O ₂

NO ₂ + NO → N ₂ O ₃

NO ₂ + NO ₃ + M → N ₂ O ₅ + M

N ₂ O ₅ + H ₂ O → 2HNO ₃

N ₂ O ₃ + H ₂ O → 2HNO ₂

The above reactions are possible only in the presence of air, therefore, in direct-acting plasma reactors, synthesis takes place only in a small volume directly at the surface of the water.

It is also known that the interaction of cold plasma with water leads to the active formation of hydrogen peroxide [Iulia-Elena Vlad Time stability of water activated by different on-liquid atmospheric pressure plasmas / Iulia-Elena Vlad, Sorin Dan Anghel // Journal of Electrostatics 87 (2017 ) 284-292 | https://doi.org/10.1016/j.elstat.2017.06.06.002].

The most chemically reactive particles that occur in a gas discharge in water vapor are OH radicals.

OH radicals accelerate the formation of nitric oxide

N + OH → NO + H

N ²⁺ + O ₂ → N ₂ O + O

And also participate in the formation of anion NO ₂ ^-

HO ₂ ^- + NO ₂ ^• → NO ₂ ^• + HO ₂ ^•

Thus, cold plasma in an air environment with the presence of air and water vapors makes possible the simultaneous appearance of molecules.

NO ₂ , NO ₂ ^- , HNO ₂ , H ⁺ , H ₂ O, H ₂ O ₂ , OH, NO, O ₂ ^-

These molecules are key elements necessary for the synthesis of a complex of ONOO ^- peroxynitrite and ONOOH peracetic acid.

HNO ₂ + H ₂ O ₂ → ONOOH + H ₂ O

NO ₂ ^- + H ₂ O ₂ → ONOO ^- + H ₂ O

NO + O ₂ ^- → ONOO ^-

NO + O ₂ ^- → ONOO ^-

OH ^• + NO ₂ ↔ONOOH

ONOO ^- + H ⁺ ↔ONOOH

ONOO ^- / ONOOH are powerful oxidizing agents and a powerful biological agent that can penetrate and destroy microorganisms. [Maria SS1, Lee J, Groves JT, Peroxynitrite rapidly permeates phospholipid membrane, Proc Natl Acad Sci USA. 1997 Dec 23; 94 (26): 14243-8]. The lifetime of peracetic acid is many times higher than free radicals OH ~ 10 ^-7 -10 ^-9 s and thus the complex ONOO- / ONOOH, therefore, in the present invention, it is the nitrogen compounds ONOO- / ONOOH, NO, NO2 that play a key role in the sterilization effect.

Thus, the emergence of long-lived nitrogenous oxidizing agents necessary for the disinfecting effect occurs due to the appearance of OH radicals in a cold plasma. The occurrence of a large number of OH radicals is a key factor in the effectiveness of the present invention, so we will consider it in detail. Nevertheless, OH radicals themselves do not play a significant role in sterilization due to their short lifetime.

Two ways of the appearance of OH radicals are described.

Dissociative adhesion reaction:

e + H ₂ O → H + OH

The reaction of water with an oxygen atom ¹ D:

O + e → O ( ¹ D) + e

O ₃ + hν → O ₂ + O ( ¹ D)

O ( ¹ D) + H ₂ O → OH + OH

The above reactions require high energies of free electrons and have a low cross section. In this regard, it is necessary to ensure, on the one hand, a long contact time of water vapor with a plasma discharge in air, and on the other hand, it is necessary to maintain a high electric field strength to accelerate free plasma electrons to the required energies. The difficulty, however, is that the presence of water significantly reduces the energy of free electrons due to inelastic collisions.

In the present invention, the problem is solved as follows:

1. It is not water itself that is fed into the discharge chamber, but moist air. Thus, a relatively low water vapor content is provided, which prevents electron energy losses.

2. The use of a barrier discharge, in which a high electromagnetic field is achieved and, as a result, a high energy of free electrons.

3. The high content of ozone molecules in the barrier discharge for photolysis with the formation of excited mono-oxygen O ( ¹ D).

4. Repeated, up to 30-60 times per minute, activation of water by plasma-treated moist air in the circulation circuit.

5. Additional water treatment in the form of fog or fine droplets with plasma directly at the outlet of the tank before treatment

As already mentioned, during the treatment of water with cold plasma, hydrogen peroxide is synthesized, which requires significantly lower electron energies for dissociation. Therefore, when processing the resulting solution directly at the outlet of the reactor, a significant increase in the disinfecting properties of the solution occurs due to the decomposition of peroxide into OH radicals.

The addition of a small amount of hydrogen peroxide (~ 0.3-0.5%) in the initial solution increases the efficiency of the device.

Thus, the essential differences of the claimed invention are that

a. active particles are long-lived radicals of nitrogen and oxygen, and not OH radicals;

b. it is water vapors that play the main role, and hydrogen peroxide is only an accompanying and optional element to enhance the effect.

Using a barrier discharge to activate vapors is the safest, since it works without open electrodes, the highest density of free electrons. In addition, a large amount of ozone barrier discharge when interacting with water and accelerates the formation of active particles of nitrogen and oxygen.

Claims (1)

A device for disinfection, including a tank with a working solution, a pump with an ejector connected to it, connected to a discharge chamber, characterized in that the pump with an ejector forms a circulation circuit for repeatedly activating the working solution with moist plasma-treated air, and the discharge chamber is a chamber with coaxial conductive cylinders connected to a high-voltage source of alternating voltage and separated by a barrier of dielectric, or with parallel tubes of dielectric inside There are conductive rods connected to a high-voltage source of alternating voltage, either with parallel conductive plates connected to a high-voltage source of alternating voltage, separated by a dielectric layer, or with a tube of dielectric, on the outside of which there is a conducting cylinder, and inside there is a conducting spiral connected to a high-voltage source alternating voltage, or with two electrodes connected to a high-voltage alternating source, placed inside the dielectric span of.

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