RU2549244C1 - Device for water treatment by pressure flotation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: device makes it possible to treat not only water but other liquids close in viscosity to water, for instance, benzenes, diesel fuel, sunflower seed oil, wine material, etc. The water treatment device comprises chambers installed at the distance from each other that are open from top with a layer of filtering material, pipelines with hydraulic locks, supply and drain nozzles. Supply nozzles are installed under the layer of filtering material. Chambers are divided into filtering elements with multi-layer filtering materials, which are retained tightly along the perimeter with multi-section frames. Each chamber for effective operation in regeneration mode is provided at least by one vibrator with parameters, which are determined by formulas, and a radiator for ultrasonic frequency for disinfection at impact capacity of at least 2 W/cm.

EFFECT: invention makes it possible to improve ten times and more the main process characteristics of a filter and perform simple regeneration of filtering material and its disinfection.

Description

The invention can be used in many industries and relates to the field of purification of liquids, in particular iodine, from dispersed impurities. The scope of its application is limited to the method of water purification by pressure flotation. The pressure flotation method consists in saturating the wastewater with air under excessive pressure, followed by a decrease in pressure to atmospheric pressure. In this case, intense desorption of air and the release of a large number of small bubbles occurs. Bubbles, with particles of fat and suspension adhering to them, float, which can significantly accelerate the process of separation of fatty substances from wastewater. However, as experience in the commercial operation of such plants has shown, the effect of purification of fat-containing wastewater does not exceed 50-60%. The main design flaws are the use of a bubbler type pressure tank, which does not provide sufficient saturation of the wastewater with air; distribution of wastewater in the flotator using perforated pipes, which are quickly clogged with grease and suspended solids. The most important node for a pressure flotator is the condition for creating a water-air mixture. Two schemes for solving this problem are possible:

1) air supply by pump bypass through the ejector;

2) air supply by the compressor to the pressure pipe in the area between the flotation pump and the receiver.

The first option, despite the fact that it is used everywhere, it has significant disadvantages:

1) in the presence of a bypass pipeline, the efficiency of the pump is reduced by 25% or more;

2) air can be supplied to the pump no more than 3% - with a larger cavitation mode for the pump to work.

The second option is rarely used.

You can supply compressed air from the compressor to the receiver. This method is used at the Zaporizhzhya nuclear power plant. Its disadvantage is the low efficiency of the pressure flotator. An analogue is the invention of a pressure flotation unit RU 2272786, 03/27/2006. The invention relates to a device for the treatment of industrial wastewater, and is intended for the treatment of waters contaminated with oil wastes, products of their processing, fats, oils, products of organic synthesis, surface-active substances, fine suspensions, activated sludge, etc. The flotation water treatment plant has a main flotation chamber, a centrifugal pump, a flaking contact chamber connected in series to the main flotation chamber using perforated pipes configured to supply purified water to the foam layer of the chamber, a hydraulic elevator connected by a pressure pipe to a centrifugal pump and a sewage pipe water. The flotation chamber is equipped with microporous filter tubes for passing air through them, and is sequentially located with a chamber for collecting purified water. The advantage of this installation is that the air is supplied in a dispersed state. The disadvantage of this installation is that these bubbles do not dissolve in water under pressure, but are immediately fed to the flotation chamber.

The prototype is to take the invention RU 2323160, 04/27/2008. The invention relates to a flotation water treatment plant, which includes a flotation device consisting of a flotation chamber into which flocculated raw water is mixed with microbubbles produced by a pressure boosting and depressing unit, collection modules located in a flotation chamber equipped with perforated assembly device. The disadvantage of this device is that microbubbles of air are not calibrated by size, but are created as a result of simple mixing, in which there is uncontrolled quality of air dispersion.

A device is proposed to improve the pressure flotator mode. The pressure flotator circuit consists of a flotation chamber, a perforated assembly device, a pressure increase and pressure relief unit, a pressure tank, and collection modules. In this flow chart, according to the invention, a device for preparing a water-air mixture for dissolving it under pressure in a pressure tank is proposed.

This device eliminates the disadvantages of similar devices and creates new technological capabilities:

- increase the level of saturation of water with compressed air;

- the optimal time for mixing water and air is regulated;

- without changing the performance of the installation, it is possible to change the mixing rate of water and air in the mixers;

- constructively, due to pore sizes up to 5 microns, the necessary sizes of air microbubbles are set in the filter cartridges.

The list of figures of the drawing. This device consists of the following sequentially located and technologically related structural elements: flotation pump 1, which raises the water pressure to 5-7 atm; water flow meters 2 that control the amount of water for flotation; shutoff valves 3, to create several technological schemes: serial, parallel, in mixed versions; compressor 4 to create increased air pressure, more than the pressure in the flotation pump; gas flow meters 5 with valves 6, adjusting the ratio of air to water in the mixers; mixers 7, creating a uniform mixture of water and air; pressure tank 8, which dissolves air in water until it is completely saturated; flotation chambers 9, which allow air to escape to the surface of the water along with floatable impurities; mixers 7 for supplying and discharging water; filtering cylindrical cartridges 13, which can create dispersed microbubbles with air up to 5 microns in size with air; nozzles 14 for supplying compressed air.

This device works in this way. Technological elements of the device, interconnected sequentially by the movement of water, air, mixture. The flotation pump 1 is turned on and the shutoff valve 3 sets its operating mode for flow and pressure. Then the water enters the mixer 7, where the movement along the cartridge 13 takes place in a spiral. The valve 6 opens on the compressed air pipeline, and the amount of air supplied to the system is set on the flowmeter. The air enters the system in a dispersed form (dispersion of microbubbles up to 5 microns of air is created by a filtering cartridge 13 with pore sizes of up to 5 microns), the drains are evenly mixed in the volume, as they constructively create a flow rate of drains up to 7 m / s, and, from - for the circular movement of the drains between the outer surface of the cartridge 13 and the walls of the pipe 10, they are intensively mixed. By technology, a connection scheme is selected from several mixers to create the necessary performance and degree of saturation of air in the created emulsified air-water mixture.

With this device, you can select a mixing time of up to 10 s. Thus, this device performs several technological tasks:

- according to the liquid and air counters, the optimal percentage composition of the air-water mixture is created for flotation;

- the required dispersion of air is set: by the pore size of the cartridges 13 and the feed rate in the device;

- drains are mixed evenly with air;

- sets the necessary time for the mixing process.

To solve technological problems of greater saturation of effluents with cleaning air, due to the limited throughput of filtering cartridges, increasing (or decreasing) the time of mixing water with air, decreasing (or increasing) hydraulic resistance, it is proposed to create these mixers in one design from several pieces with strapping them sequentially, in parallel and in mixed modes. The efficiency of the mixers will be determined, in addition to cleaning efficiency, also by external factors: the thickness and time stability of oil sludge on the flotator mirror; the amount of air discharged from the pressure tank - it should be minimal.

Literature. 1. Matsnev A.I. Wastewater treatment by flotation. K .: Budivelnik, 1977. -128 p.

2. Patents of Russia: RU 2272786, 03/27/2006, RU 2323160, 04/27/2008.

Claims (2)

1. A device for automatically controlling the liquid at the maximum flow rate, comprising inlet and outlet pipes, a regulating tank and a float open from above, characterized in that the inlet pipe enters the regulating tank and has a strictly vertical pipe section, the end of which is sealed, the upper part of the vertical pipe has a perforated section, the total section of the perforated holes in the pipe is 1.5-3 times larger than the area of the inner section of the pipe of the supply pipe, the gap between een outdoor pipe diameter and the inner diameter toroidal float is 0,012-2 mm depending on the pipe diameter, and discharge pipe arranged regulating throttle. 2. The device according to claim 1, characterized in that the height of the toroidal float is not less than the length of the perforated section of the underwater pipeline, while the float is placed with the possibility of its movement only along the axis of the supply pipeline in its vertical section.

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