SU977398A1 - Process and apparatus for aerating water - Google Patents

Description

The invention relates to the aeration of water, namely, sewage during treatment in aeration tanks or natural waters with low oxygen content.

A known method of aerating water with air passed through porous partitions 1.

However, this method gives a small interface between the liquid and gas phases, a low dissolution rate. gas in water and, consequently, a low percentage of dissolution of gas supplied to water.

The closest in technical essence to the present invention is a method and apparatus for aerating standing natural water with air or oxygen-containing gas dispersed in a Venturi pipe. A high pressure pump picks up water and feeds it into the venturi nozzle (mixer). Air is discharged into the venturi and dispersed there. The air / water mixture under pressure is fed into the aerated zone at the desired depth G2.

; During mechanical crushing of air in the mixer, mixing of the liquid and gas phases occurs. The sucked and crushed air at the nozzle exit of the mixer is released from the water / air mixture in the form of bubbles 0.05-10 3-D ,. Bubbles of this size quickly rise to the surface of the water, and, due to the high rate of ascent and the small interface, significant air dissolution in water

10 does not occur. Thus, using this device, it is not possible to achieve a high concentration of oxygen in the aerated zone when it is pumped once.

15

To achieve a high concentration of oxygen in the water of the aerated zone (for example, from 5 mg / l - the initial value is up to 9 mg / l and above) when using the device

20 multiple pumping of the entire volume of water, which gives a gradual saturation of it with oxygen. However, this makes the process of saturation energy-intensive, time consuming and therefore inefficient.

The purpose of the invention is to increase the oxygen concentration in the aerated water when it is pumped once.

The goal is achieved by teM (

30 that part of the water supplied by the pump.

sprayed in an aerator under excess pressure in an environment of oxygen-containing gas, then mixed with oxygenated water with non-aerated water is mixed and fed into the aerated zone.

The ratio of water supplied to the aerator and non-aerated water supplied to the mixer is 1: 1.2-6. .

A device for aerating water contains a pump for feeding water and. a mixer, a nozzle aerator, a nozzle for connecting the aerator to the pressure filament through the pressure regulator and the water supply nozzle.

When spraying water in the aerator in an environment of an oxygen-containing gas at an overpressure, an oxygen concentration in water exceeding the equilibrium at atmospheric pressure is achieved. During the subsequent mixing of oxygenated water with non-aerated water in the mixer at the outlet of the mixer, the oxygen content in water remains above equilibrium by 50-100%. A jet of water from the mixer carries dissolved oxygen. C. concentration above equilibrium. Excessive (super-equilibrium) amount of oxygen is released in water in the form of tiny bubbles (the size of gas bubbles is smaller than the size of bubbles obtained by any other method), and water with an equilibrium oxygen content is mixed with water of a water body or aerotank, thus increasing the oxygen concentration in the aerated zone. The bubbles released in the water rise upwards. Since the size of the bubbles is as small as possible, the lifting speed I1 is also small (compared to the lifting speed of bubbles obtained by any other method), and the gas-liquid interface is the maximum possible. At a low rate of ascent of the bubbles and at a large interface, an intensive dissolution of oxygen in the water of the aerated zone is observed, which. It is also a source of water oxygenation.

When the ratio of water supplied to the aerator and non-aerated water supplied to the mixer is less than 1: 1.2, the efficiency of aeration drops by a factor of almost two, if this ratio (1% is greater than 1: 6, then the efficiency of oxygen consumed for aeration.

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

A device for aerating water includes a pump 1 for supplying water, a mixer 2, an aerator 3., to the walls

the nozzles 4 are mounted in it. The aerator has a water level regulator 5 installed at the inlet of aerated water to the mixer. The gas pressure in the aerator is kept constant by means of a pressure regulator 6 mounted on a gas connection connected to the aerator. The device can be installed at any desired depth of the reservoir or aerotank and turned in any direction.

The device works as follows.

A part of the water supplied by the pump is sprayed in an aerator under pressure in an oxygen-containing gas medium, then the oxygenated water is mixed with non-aerated water and fed into the aerated zone.

Example. An aerator (with a volume of 0.07 m) is installed in a pond at a depth of 1.3 m. The pump delivers water to the aerator under a pressure of 7.7-10 Pa. The oxygen concentration in the water of the reservoir before aeration is 5 mg / l. The oxygen concentration in the water inside the aerator is 85 mg / l. Water from the aerator enters the mixer, where it mixes in a ratio of 1: 3.6 with non-aerated water from the reservoir, with the result that the oxygen concentration in the water at the outlet of the mixer is 22-23 mg / l. At a temperature of 280 K, the equilibrium concentration of oxygen dissolved in water of the reservoir is 13-14 mg / The remaining amount of oxygen (8-10 mg / l) is released in the form of bubbles and additionally saturates the water with hydrogen gas due to the dissolution of the gas as the bubble rises. With a mixer capacity of 38.6, after 5 hours of operation of the device, the oxygen concentration in the water of the aeration zone (the area bounded by a circle with a radius of 9 m and a reservoir depth of 2.5 m) reaches 9.2 mg / l.

The table presents the comparative data of the test results of the proposed method and the method adopted for the prototype.

For convenience of comparing the considered methods and devices, the test conditions are the same in both variants: the aerated zone is delineated with a radius of 9.5 m, the water depth is 2.5 m, the device performance is 38.6, the goal is to achieve a concentration of oxygen in the aerated zone 9.29, 7 mg / l.

As follows from the above data, the proposed method and device are characterized by high efficiency, the aeration time is reduced by 12-60, as many times

the amount of pumped water is reduced, which reduces energy costs during operation of pumps and depreciation of the installation.

The main indicator that leads to an increase in the efficiency of the method and device is to ensure a high output concentration of oxygen in the water at the outlet of the device.

The device is recommended to be used to increase the oxygen concentration in drinking water supply systems and fish ponds to prevent fish from sticking and water decay, as well as to aerate sewage when processing them in aeration tanks to intensify oxidation processes.

The change in oxygen concentration in water after passing through the installation (at the outlet of the device), mg / l

The oxygen concentration in the water of the aerated zone of the reservoir, mg / l, through, h:

O (initial concentration)

2

3.5

five

15 Duration of aeration, h

The multiplicity of exchange (the ratio of the volume of pumped water to the volume of the aerated zone of the reservoir)

Claims (3)

1. Method of aerating water, including water saturation with oxygen and supplying it to the aerated zone, in which, in order to increase the oxygen concentration in the aerated water when it is pumped once, a portion of the water is saturated with oxygen by spraying it in an aerator under an overpressure of oxygen-containing gas, then the oxygenated water is mixed with non-aerated water . 2. Method of pop, 1, characterized in that the ratio of water supplied to the aerator and non-aerated water supplied to the mixer is J .: 1, 2-6. 1-1.5 17-18 five 7.25 8.61 9.72 aeration is complete 4.3-5 4.69 0.23-0.27 3. A device for aerating water, containing a pump for supplying water and a mixer, characterized in that, in order to increase the oxygen concentration in the aerated water, the device is equipped with an aerator with nozzles, a nozzle for connecting the aerator with a pressure source through a pressure regulator and a water supply nozzle . Sources of information taken into account in the examination 1. Perry J. Engineering's Handbook. T. II, Himi, 1969, p. 90. 2. For the application of the Federal Republic of Germany No. 2447337, 45 cl. From 02 to 1/00, published. 04.15.76.