SU1699616A1 - Method for aeration of liquid - Google Patents

Abstract

The invention relates to the aeration of a liquid and can be used in the flotation enrichment of minerals, wastewater treatment and in other areas. The goal is to reduce energy consumption for aeration. For carrying out the process, air is supplied to the aerator and a gas-liquid surface is formed, to which a jet of liquid is supplied from the nozzles. The liquid jet is pre-saturated with air or gas in an amount of from 10 to 50% of the volume of the liquid. The saturation of the liquid jets is carried out under the overpressure of air or gas, or with the simultaneous overpressure of air or gas and the vacuum created in the aerator using a vacuum pump. Pre-saturation of a jet of fluid with air or gas increases their ejection capacity and, as a result, helps to reduce energy consumption for aeration. 1 dw., 2 tab.

Description

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The invention relates to liquid aeration methods and can be used in the flotation enrichment of minerals, wastewater treatment and in other areas.

In mineral processing, methods are known for surface aeration of a liquid with jets.

A device for aerating a liquid contains a container, an aerator with pipelines for supplying liquid and gas under pressure to it, and provides deep aeration of the liquid with the help of liquid jets flowing onto the gas-liquid section.

The method of aeration of the liquid during flotation involves the supply of a jet to the interface by pulses.

The liquid aeration device is a jet aerator with an aeration and adjustment unit.

The disadvantages of the known solutions are significant energy costs, the difficulty of controlling the ejection coefficient, the inability to increase the ejection coefficient in a rational (1-1.5 these) areas of overpressure at which jets of liquid are supplied.

The closest to the present invention is a method of aerating a liquid, in which a flat-shaped liquid jet is used, the angle of jet supply to the liquid surface is 20-75 °, height is 30-50 cm and pressure is 1-1.5.

The disadvantages of this method are the considerable energy costs caused by the need to ensure effective aeration of air.

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and creating high jet velocities by increasing fluid pressure.

The aim of the invention is to reduce the energy consumption for aeration by increasing the ejection capacity of the jet.

This goal is achieved by introducing into the liquid before its supply in the form of a jet to the gas-liquid-gas (air) interface in an amount of 10-50% of its volume under excessive pressure or under the action of excessive pressure and vacuum. At this flow rate of gas (air), the surface of the jet is intensely turbulized, due to which the trapping of air by its irregularities increases as it moves from the nozzle to the gas-liquid interface. Air ejection increases with increasing jet velocity and turbulence. With the help of high-speed filming, it was established that the ejection coefficient K depends on the irregularities of the jet surface.

, 4 (/ g) 2

| 0, b-.

+ 2 (/ g) 0.1

where Qr is the volume of ejector gas;

Oj - volume of fluid;

K-factor of surface roughness;

r is the jet radius at any of its points.

With moderate values of the surface irregularities of the jets (low turbulence) values of K 2, for high turbulence values of K 2.

The proposed aeration method allows the surface irregularity factor Ј to be adjusted and the ejection coefficient to be changed accordingly.

A comparative analysis with a known method shows that the proposed aeration method is characterized in that the liquid is subjected to a preliminary gas saturation before it is supplied in the form of jets.

The drawing shows a scheme for carrying out the proposed method.

The diagram shows a gas nozzle 1, a gas supply nozzle (2), a liquid supply nozzle 3, a mixer 4, a jet b, a gas-liquid interface 6, an aerated volume of liquid 7.

The fluid under pressure (in the case of vacuum aeration of the fluid under the action of atmospheric pressure in the case of combined aeration under the effect of overpressure and vacuum) flows through pipe 3 into mixer 4, to which air (gas) is supplied through pipe 2 through a nozzle 1 water-gas mixture in the form of a turbulent jet 5 falls on the surface

fluid layer. A drop jet draws air from the atmosphere into the surface layer 6 and forms an aerated volume of liquid 7. To create a vacuum, the nozzle is placed in the housing 8, to which a vacuum pump is connected via pipe 9.

The results of research on the effect of gas saturation of circular liquid jets on their ejector capacity under the conditions of

0 aeration at atmospheric pressure and in vacuum are presented in table 1.

The data in table 1 show that the most rational ratio of the air-water environment is

5 an interval of 10-50% of air to the supplied volume of fluid, under conditions of which the ejection coefficient increases 2.5-4.0 times as compared with the conditions of the known method.

0 Due to the increase in the ejection ratio, the energy consumption for the aeration process is reduced to an appropriate extent.

Energy Comparative

5 for aeration under the conditions of the known and proposed methods are presented in Table 2.

From the data of Table 2 it can be seen that the preliminary gas saturation of the liquid before its

By applying it to jet nozzles, the specific energy consumption for aeration is reduced by 30% when transferring fluid from overpressure to atmospheric pressure and 55% when transferring fluid from atmospheric pressure to vacuum. The difference in the specific cost of aeration at atmospheric pressure and in vacuum is due to the fact that installation is required for aeration at atmospheric pressure.

Q pump for supplying liquid under pressure and installing a compressor for supplying gas (air under the same pressure. In the case of vacuum aeration, the implementation of the method is achieved by operating only vacuum-5 coca, which ensures a given vacuum, in which liquid and gas (air) enter the system by gravity due to the generated discharge. In the case of combined aeration, the specific

0 the energy consumption remains at the level of the vacuum aeration process, since such aeration requires the installation of a low-pressure pump and blower, which require additional

5 energy costs.

Practical implementation of the proposed method of aeration can be carried out in flotation machines of the type FP 6, 3 C (5), where pneumohydraulic aerators are used. The use of pre-gassing will reduce energy costs by allowing the process to be conducted at a lower fluid pressure, reducing process dilution and reducing fluid consumption. increasing the degree of fluid aeration and, accordingly, improving the performance of the flotation machine and improving the technological indicators of the process.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A method for aerating a liquid, comprising feeding air and liquid into the aerator. “Overpressure in experiments 0.05 NPa. Aeration method Famous Offered: at atmospheric pressure (fluid supply from overpressure to atmospheric) in vacuum (fluid supply from atmospheric pressure in vacuum) combined method in vacuum (feed overpressure liquids in vacuum)  In parentheses are the percentage of the known method. forming a gas-liquid surface; supplying liquid jets to a gas-liquid interface, characterized in that, in order to reduce energy consumption for aeration by increasing the ejecting ability of jets, liquid jets are saturated with 0-50% of air volume or gas, wherein the saturation of the liquid jets is carried out under an overpressure of air or gas or under the simultaneous action of a discharge generated in the aerator and an overpressure of air or gas. table 2 Specific energy consumption for aeration, kWh / m3 of air 0.17 0.12 (70%) 0.077 (45%) 0.08 (47) t Vacuum Gas (bozda)