RU2498944C2 - Multi-section contact tank for ozone water treatment - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to equipment for treating water by ozonation and can be used particularly in decontaminating drinking water in water supply systems of cities and population centres and disinfecting recycled pool water. The contact tank has multiple interconnected reaction sections arranged in series between the pressure compartment of the tank, connected to a source of the water to be treated, and a drainage compartment, having an outlet for feeding water to the consumer, and also equipped with a system for feeding the ozone-air mixture into each reaction section and dispersion thereof in water, a system for removing and destroying residual ozone in the ozone-air mixture. The contact tank further includes inter-section by-pass compartments which change the direction of water into the opposite direction, and each section is further equipped with devices for uniformly distributing water on its cross-section. Below the level of the ozone-air mixture dispersers, there are either similar perforated pipes, whose open ends in different sections are respectively linked to the pressure and inter-section by-pass compartments situated in front of them, or there are perforated horizontal partition walls.

EFFECT: invention improves the quality of drinking water and efficiency of using ozone produced for water treatment.

5 cl, 5 dwg

Description

The invention relates to techniques for treating water with ozonation and can be used, in particular, for the disinfection of drinking water in the water supply systems of cities and towns, for the disinfection of recycled water pools.

The prior art installation for ozonation of water, containing an air preparation system connected to an ozone generator, an electric power source, a reaction tank in the form of a contact reservoir, divided into separate sections by vertical transverse partitions, alternately adjacent to the bottom of the contact reservoir, and partitions installed with a gap relative to the bottom, providing a consistent flow of water from section to section from the entrance to the contact reservoir to the exit from it, while at the bottom of the hour and each section contains dispersants of the ozone-air mixture in communication with the ozone generator, a residual ozone destruction system, a wave generator or a device for exciting shock waves located in the lower part of the contact reservoir section, which can be combined into separate container-type modules (RF Patent No. 2169122, C02F 1/78, publ. 2001).

The disadvantages of the known installation include the fact that the direction of movement of water in the sections does not occur parallel to the walls, but diagonally, which is due to the design of intersectional partitions (Figure 1), while the initial direction of movement of the bubbles of the ozone-air mixture from the bottom up.

As a result of this, in each section of the contact reservoir two angular stagnant zones are formed with circular circulation of water and ozone-air mixture bubbles.

In stagnant zones, the concentration of ozone dissolved in it increases, as a result of which in these places the output of ozone from the bubbles of the ozone-air mixture slows down, and the concentration of residual ozone in the gas cushion of the section increases.

In addition, when the direction of the flow of water diagonally decreases the cross-sectional area of the core of the stream and decreases the residence time of water in the reaction zone of the section.

A prior art installation for water ozonation is also known, comprising a compressor, the output of which is connected to an air preparation system connected to the input of the ozone generation unit, to the output of which are connected the inputs of the bubble-forming dispersed ozone-air mixture located in the lower part of the contact pool, which is divided into N sections using N-1 transverse vertical partitions, with partitions with an even serial number adjacent to the bottom of the pool, transverse vertical partitions with an odd order your number has a height greater than the water level in the contact pool, the water inlet is located in the upper part of the first section, and the water outlet in the last section, characterized in that the transverse vertical partitions with an even serial number have a height greater than the water level in the contact pool, partitions with an odd serial number are adjacent to the bottom of the pool, in the upper part of the sections with numbers n> 1 there are additional water inlets, the water outlet is connected with additional water outlets located in the lower part of the sections numbered n = 1, ..., N-1 (RF Patent №2214369, C02F 1/78, publ. 2003).

This installation has the same drawback as the installation according to the patent of the Russian Federation No. 2169122. The water in the sections also moves diagonally, only the direction of water movement in the sections is reversed in comparison with the installation of the aforementioned patent (see Figure 2).

The closest analogue of the invention, taken as a prototype, is an installation for ozonation of water, including an air pretreatment system, a power source, an ozone generator in communication with dispersants of the ozone-air mixture installed in the bottom part of the contact reservoir section, a water supply system in communication with the source the treated water, a discharge pipe for purified water and a system for the sequential flow of the treated water from the section to the section containing intersection fume DKI alternately adjacent to the bottom of the contact tank and partitions installed with gaps relative to the bottom (RF patent №2207985, C02F 1/78, publ. 2007).

The disadvantages of this installation include the fact that the water flow in the sections of the contact tank moves diagonally, and the initial flow of the ozone-air mixture has a vertical direction from bottom to top, resulting in angular stagnant zones with local circular circulation of water with ozone dissolved in it. For this reason, the estimated time spent in the ozone treatment zone for the diagonal flow of water is reduced, and for the circulating part of the water it is increased, which reduces the degree of water purification as a whole.

The objective of the proposed technical solution is to provide unidirectional movement of the water flow in all sections of a multi-section contact tank from the bottom up (a satellite stream of water and ozone-air mixture) with sequential flow of water from section to section and uniform distribution of water over the cross section of each section when moving water from dispersants to the water horizon.

The solution to this problem is achieved by the fact that in the contact tank for water treatment with ozone, including several interconnected reaction tanks (sections), preferably made of concrete each in the form of a parallelepiped, located between the pressure compartment connected to the source of the treated water and the drain compartment, having a tap for supplying water to the consumer, and also equipped with a system for supplying an ozone-air mixture to each reaction section and its dispersion into water, a drainage system and destruction system tatochnogo ozone in the ozone-air mixture, additionally installed bypass intersectional compartments, and each section is further equipped with devices uniform water distribution over its cross-section.

Intersectional bypass compartments - 6, 7 (Figure 3) are made of two parallel walls spaced from each other at a distance of 0.8 ... 1.4 m, above the water level in adjacent sections.

Uniform water distribution devices are located on two horizontal levels. Above, under the water horizon level in sections, perforated pipes muffled from one end face are installed - 8, 9, 10 (Figure 3), which provide water reception through the perforation holes from below and its supply through open ends to the bypass intersection compartments located behind them - 6, 7 and the drain compartment - 5 (Figure 3). At the bottom below the location of the dispersants of the ozone-air mixture - 16, 17, 18 are installed or similar perforated pipes - 11, 12, 13 (Figure 3), which allow water to be received through the open ends from the pressure head - 4 and intersection compartments - 6 located in front of them , 7 and feeding it from the bottom up into the reaction vessels of the section - 1, 2, 3, or as an alternative, horizontal perforated partitions - 19, 20, 21 are installed (Figure 4). At the same time, water is received in the section through openings - 22, 23, 24 located in the walls separating the sections from the pressure and intersection compartments, below the perforated partitions (Figure 4), and water is supplied to the reaction vessels of the section through the perforation holes in the partitions .

The perforation holes in the pipes and partitions installed at the bottom of the sections are selected with a diameter of 20 ... 25 mm, and their total flow area is 0.01 ... 0.02 of the cross-sectional area of the section.

At the lower and upper levels, the step between the axes of the parallel installed pipes is equal to from 17 to 25% of the immersion depth of the dispersants in the section.

In the perforated pipes - 8 of the upper part of each section of the contact reservoir - 1 (see Figure 5) near the water horizon, which receive water from the working volume of the section inward through the holes in the walls and drain it through the open end, there is a longitudinal row of rectangular windows - 24 on each side, with a ratio of the height of the windows to the width, for example, 2: 1, and the total width of the windows in one row is equal to half the working length of the pipe, while in the area of the windows the pipe surface is made flat, and each row of windows is equipped with an overlay Coy - 25 with a rectilinear upper sealing lip to be mounted parallel to the working edge and below the water level in the section at a predetermined depth with equality of water flow through a single window - 24.

The implementation of perforated pipes for distributing the treated water between the sections of the contact tank with overlays for rectangular openings that regulate the thickness of the water layer over the overflow edge increases the uniformity of the distribution of water flows over the cross section of the contact tank section and, ultimately, increases the efficiency of the water ozonation process.

The horizontal perforated partitions are identical in function to the perforated pipes.

Horizontal perforated partitions can be made of reinforced concrete, which can reduce material costs compared to perforated stainless steel pipes or ozone-resistant plastic.

Sectional contact tank is illustrated by drawings. Figure 1 shows a diagram of changing the direction of the flow of water to the opposite when it flows from section to section and the flow of water in each section in a three-section contact tank, adopted as a prototype. Arrows indicate the direction of water movement.

Figure 2 shows a diagram of changing the direction of the flow of water to the opposite when it flows from section to section and the flow of water in each section in a three-section contact tank-analogue with an additional water inlet.

Figure 3, shows a structural diagram of the proposed three-section contact tank, where the numbers denote: 1, 2, 3 - sections of the contact tank, 4 - pressure compartment, 5 - drain compartment, 6, 7 - bypass intersection compartments, 8, 9, 10 - perforated pipes of the upper level, 11, 12, 13 - perforated bottom pipes, 14 - inlet for water supply, 15 - outlet for draining water, 16, 17, 18 - dispersants of the ozone-air mixture. The hollow arrows show the direction of flow of the ozone-air mixture, and the simple arrows show the directions of water movement.

Figure 4 shows a structural diagram of the proposed three-section contact tank, in which horizontal perforated partitions 19, 20, 21 are installed, water is supplied from the pressure compartment and bypass compartments into the sections through openings 22, 23, 24 located below the perforated partitions.

Figure 5 shows a diagram of a perforated pipe installed in the upper part of the contact reservoir section, with a longitudinal row of rectangular windows on each side with an overhead rail with a rectilinear top working edge, ensuring equal water flow through a single window, where the numbers indicate: 8 - perforated pipe, 24 - rectangular windows, 25 - surface rail. Hollow arrows show the direction of flow of the ozone-air mixture, and simple arrows show the direction of water movement.

The claimed multi-section contact tank works as follows: under pressure in the pressure compartment - 4 (see Figure 3 for a three-section contact tank) water is supplied to the first section - 1 through perforated pipes - 11 installed in the bottom part of this section. When water jets exit from the internal cavity of the pipe into the section water array through perforation holes with a diameter of 20 ... 25 mm, due to the sharp expansion of the jet, a sharp decrease in speed occurs from 600 ... 700 mm / s and at a distance of 300 ... 400 mm from the outlet the water velocity throughout the cross section of the section is 5 ... 8 mm / s, which is confirmed by experiments.

The water flow remains evenly distributed at the level of dispersants and above and begins to locally accelerate immediately before entering the holes of 20 ... 25 mm perforation of pipes installed above the water level. Then, the water flow through the open ends of the perforated pipes - 8 enters the first bypass intersection compartment - 6 and again through the open ends of the bottom perforated pipes - 12 of the second section, flows from bottom to top evenly across the cross section upwards of the second section - 2. For subsequent sections, the picture of the flow of water and the ozone-air mixture remains similar to that considered. From the open ends of the perforated bottom pipes of the last section, water enters the drain compartment - 5 and then goes to the consumer.

This design of a multi-section contact tank fully solves the problem and ensures uniform distribution of the water flow over the cross section of the section at the entire height of the treated water layer, and provides in each section a satellite stream of water and ozone-air mixture.

The proposed device for the uniform distribution of water over the cross section of the reaction vessel (section) can also be effective in a single-section contact tank. In this case, the open ends of the upper perforated pipes of the first section communicate directly with the drain compartment of the contact tank.

Claims (5)

1. A multi-section contact tank for treating water with ozone, comprising several interconnected reaction sections, preferably made of concrete, each in the form of a parallelepiped, which are sequentially located between the pressure compartment of the contact tank connected to the source of the treated water and a drain compartment having a branch for supply water to the consumer, as well as equipped with a system for supplying an ozone-air mixture to each reaction section and its dispersion into water, a drainage system and destruction residual ozone in the ozone-air mixture, characterized in that between sections additionally installed intersectional bypass compartments and each section of the contact reservoir is additionally equipped with devices for uniform distribution of water over its cross section located at two horizontal levels: above, under the level of the water horizon in the section in the form of parallel mounted perforated pipes plugged from one end, the open ends of which in different sections are respectively communicated with them intersection bypass compartments and a drain compartment, and below the location of the dispersants of the ozone-air mixture or in the form of similar perforated pipes, the open ends of which in different sections respectively communicate with the pressure compartment and intersection bypass compartments located in front of them, or in the form of perforated horizontal partitions , the spaces under which are communicated through openings made in the walls of the section separating them from the pressure and intersection bypass located in front of them ny compartments. 2. The multi-section contact tank according to claim 1, characterized in that the intersection bypass compartment is made of two parallel walls higher than the water level in the sections spaced from each other at a distance of 0.8 ... 1.4 m 3. The multi-section contact tank according to claim 1, characterized in that the perforation holes in the pipes or partitions installed below the level of dispersants of the ozone-air mixture are selected with a diameter of 20 ... 25 mm, and the total area of their passage section is 0.01 ... 0, 02 cross-sectional area of the section. 4. The multi-section contact tank according to claim 1, characterized in that the axes of the perforated pipes at the top and bottom of the section are installed in increments of 17 to 25% of the immersion depth of the dispersants in the section. 5. The multi-section contact tank according to claim 1, characterized in that the perforated pipes installed in the upper part of the contact tank section, plugged from one end, are made with one longitudinal row of rectangular windows on each side with a window height to width ratio of 2: 1, and the total width of the windows in one row is equal to half the working length of the pipe, while in the area of the windows the pipe surface is made flat, and each row of windows is equipped with a surface rail with a straight upper working edge with the possibility of tanovka the working edge parallel to and below the water level in the section at a given depth to ensure equal flow rates through a single window.

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