RU2286867C1 - Method for treatment of surfaces - Google Patents

Abstract

FIELD: surface treatment processes.

SUBSTANCE: method involves using mixed working fluid for treatment of surfaces, said working fluid containing combustible and oxidizer, with carbon-containing fuel being used as combustible and aqueous solution of hydrogen peroxide being used as oxidizer.

EFFECT: increased efficiency in treatment of surfaces owing to producing of plasma flow enriched in reducing gases as a result of plasmochemical conversion of mixed working fluid vapors.

7 cl

Description

The invention relates to a method for surface treatment, in particular for burning dry paint on metal barrels.

A known method of surface treatment, which consists in supplying a mixed liquid working fluid to the working body, its evaporation, supplying vapor to the discharge chamber, heating the vapor in an electric arc discharge with an independent supply of electric current, obtaining a plasma jet enriched in reducing gases, and subsequent heating of the processed surfaces with a plasma jet (Patent RU No. 2103129, 01/27/1998 - analogue and prototype).

The disadvantage of this method is the low processing efficiency due to the fact that the plasma jet is not sufficiently enriched with reducing gases.

The technical result of the invention is to increase the processing efficiency by obtaining a plasma jet enriched in reducing gases as a result of plasma-chemical conversion of the vapor of a mixed liquid working fluid.

This is achieved by the fact that the mixed liquid working fluid includes fuel and an oxidizing agent, with carbon-containing fuel being used as the fuel, and an aqueous solution of hydrogen peroxide as the oxidizing agent in the following component ratios (wt.%):

carbon fuel 10 ÷ 60 aqueous solution of hydrogen peroxide the rest is up to 100

in this case, the vapor of the mixed liquid working fluid is supplied from the condition that hydrogen peroxide loses thermochemical stability before entering the discharge chamber, and when the vapors are heated, the current in the arc and the voltage across the arc are changed to allow the plasma-chemical processes to be controlled in accordance with the dependence

W / Q = 1.5 ÷ 9.7 kW • h / l,

where W is the average value of the power introduced into the electric arc, kW, Q is the volumetric flow rate of the mixed liquid working fluid, l / h.

This is also achieved by the fact that the concentration of an aqueous solution of hydrogen peroxide is 0.1 ÷ 65 wt.%.

This is also achieved by the fact that as components of carbon-containing fuel, substances with a fractional composition having a boiling point of not lower than 50 ° C and a boiling end of not higher than 120 ° C are used.

This is also achieved by the fact that, as a carbon-containing fuel, fuel is used based on a group of products including benzene and petroleum solvents.

This is also achieved by the fact that, as a carbon-containing fuel, fuel is used from the class of oxygen-containing hydrocarbon compounds, preferably based on a group of products including monohydric alcohols, aliphatic saturated ketones and mixtures thereof.

As a working body use a burner.

The surface treatment method is illustrated by the following examples.

Example 1. In the working body serves a mixed liquid working fluid, which includes fuel and an oxidizing agent. The fuel used is carbon-containing fuel from the group of petroleum solvents, for example Nefras C2-80 / 120. As an oxidizing agent, an aqueous solution of hydrogen peroxide with a concentration of 0.1 wt.% Is used.

Take the following ratio of components (wt.%):

Oil solvent Nefras C2-80 / 120 10 aqueous solution of hydrogen peroxide the rest is up to 100

A mixed liquid working fluid is formed in the form of an emulsion of high dispersion by known methods by means of a homogenizer, both without the use of stabilizing agents or with the use of stabilizers.

As a working body, a torch can be used in which the vapor of a mixed liquid working fluid is heated in an electric arc discharge with an independent supply of electric current, ensuring the loss of thermochemical stability by hydrogen peroxide before entering the discharge chamber. When the vapors are heated, the current in the arc and the voltage on the arc are changed to control the plasma-chemical processes in accordance with the dependence W / Q = 1.5 ÷ 9.7 kW • h / l, where W is the average value of the power introduced into the electric arc, kW , Q is the volumetric flow rate of the mixed liquid working fluid, l / h.

The resulting plasma jet is directed to the surface to be treated. Surface treatment is carried out by the recovery zone of the plasma jet.

Example 2. In the working body serves a mixed liquid working fluid, which includes fuel and an oxidizing agent. The fuel used is carbon-containing fuel from the group of petroleum solvents, for example Nefras C2-80 / 120. An aqueous solution of hydrogen peroxide with a concentration of 65 wt.% Is used as an oxidizing agent.

Take the following ratio of components (wt.%):

Oil solvent Nefras C2-80 / 120 60 aqueous solution of hydrogen peroxide the rest is up to 100

A mixed liquid working fluid is formed in the form of an emulsion of high dispersion by known methods by means of a homogenizer, both without the use of stabilizing agents or with the use of stabilizers.

As a working body, a torch can be used in which the vapor of a mixed liquid working fluid is heated in an electric arc discharge with an independent supply of electric current, ensuring the loss of thermochemical stability by hydrogen peroxide before entering the discharge chamber. When the vapors are heated, the current in the arc and the voltage on the arc are changed to control the plasma-chemical processes in accordance with the dependence W / Q = 1.5 ÷ 9.7 kW • h / l, where W is the average value of the power introduced into the electric arc, kW , Q is the volumetric flow rate of the mixed liquid working fluid, l / h.

The resulting plasma jet is directed to the surface to be treated. Surface treatment is carried out by the recovery zone of the plasma jet.

Example 3. In the working body serves a mixed liquid working fluid, which includes fuel and an oxidizing agent. Ethanol, a carbon-containing fuel from the class of oxygen-containing hydrocarbon compounds from the group of monohydric alcohols, is used as fuel. As an oxidizing agent, an aqueous solution of hydrogen peroxide with a concentration of 10 wt.% Is used.

Take the following ratio of components (wt.%):

ethanol 55 aqueous solution of hydrogen peroxide the rest is up to 100

A mixed liquid working fluid is formed as a mixture of ethanol and an aqueous solution of hydrogen peroxide.

As a working body, a torch can be used in which the vapor of a mixed liquid working fluid is heated in an electric arc discharge with an independent supply of electric current, ensuring the loss of thermochemical stability by hydrogen peroxide before entering the discharge chamber. When the vapors are heated, the current in the arc and the voltage on the arc are changed to control the plasma-chemical processes in accordance with the dependence W / Q = 1.5 ÷ 9.7 kW • h / l, where W is the average value of the power introduced into the electric arc, kW , Q is the volumetric flow rate of the mixed liquid working fluid, l / h.

The resulting plasma jet is directed to the surface to be treated. Surface treatment is carried out by the recovery zone of the plasma jet.

Thus, the invention improves the efficiency of surface treatment.

Industrial applicability.

The invention can be used in the treatment of surfaces of materials by a plasma jet, as well as for non-oxidative cutting, soldering, welding or heating of metals in repair shops and mechanical engineering during the installation of metal structures.

Claims (6)

1. The method of surface treatment, which consists in supplying a mixed liquid working fluid to the working body, evaporating it, supplying vapor to the discharge chamber, heating the vapor in an electric arc discharge with an independent supply of electric current, obtaining a plasma jet enriched with reducing gases, and subsequent heating the surfaces to be treated with a plasma jet, characterized in that the mixed liquid working fluid includes fuel and an oxidizing agent, moreover, carbon-containing fuel is used as fuel, and as a ve oxidizer - an aqueous solution of hydrogen peroxide in the following ratios of components, wt.%: Carbon fuel 10 ÷ 60, Aqueous solution of hydrogen peroxide The rest is up to 100 in this case, the vapors of the mixed liquid working fluid are supplied from the condition that hydrogen peroxide loses thermochemical stability before entering the discharge chamber, and when the vapors are heated, the current in the arc and the voltage across the arc are changed to allow the plasma-chemical processes to be regulated in accordance with the dependence W / Q = 1 5 ÷ 9.7 kWh / l where W is the average value of the power introduced into the electric arc, kW; Q is the volumetric flow rate of the mixed liquid working fluid, l / h. 2. The method according to claim 1, characterized in that the concentration of an aqueous solution of hydrogen peroxide is 0.1 ÷ 65 wt.%. 3. The method according to claim 1, characterized in that the components of the carbon-containing fuel use substances with a fractional composition having a boiling point of at least 50 ° C and a boiling point of not higher than 120 ° C. 4. The method according to claim 1, characterized in that as a carbon-containing fuel, fuel is used based on a group of products including benzene and petroleum solvents. 5. The method according to claim 1, characterized in that as a carbon-containing fuel, fuel is used from the class of oxygen-containing hydrocarbon compounds, preferably based on a group of products including monohydric alcohols, aliphatic saturated ketones and mixtures thereof. 6. The method according to claim 1, characterized in that a burner is used as a working body.