RU2776536C1 - Carousel aerotank with a sunken shaft - Google Patents

Abstract

FIELD: wastewater treatment.

SUBSTANCE: claimed invention relates to wastewater treatment facilities and is intended for deep physico-chemical and biological purification of industrial and household wastewater from suspended solids, nitrogen compounds, phosphorus, surfactants and other contaminants. A carousel aerotank with a sunken shaft has a housing. The housing consists of separate collapsible unified structural blocks interconnected by pivoting sections and fittings. The housing is made in the form of at least one ring tank using sealed connecting elements, pivoting sections and fittings. The housing contains in its volume a water-air mixture of activated sludge and wastewater. The housing is equipped with a branch pipe supplying wastewater or sludge mixture, diverting the sludge mixture or purified water with a branch pipe. The housing has at least one sunken shaft with an aeration system of the sludge mixture, at least one exciter of the movement of the sludge mixture.

EFFECT: reduction in the dimensions of structures, an increase in the efficiency of air oxygen absorption, an increase in the oxidizing capacity of treatment facilities, respectively, with reduced energy consumption.

26 cl, 3 dwg

Description

The claimed invention relates to wastewater treatment facilities and is intended for deep physicochemical and biological (combined) treatment of industrial and domestic wastewater from suspended solids, nitrogen compounds, phosphorus, surfactants and other contaminants.

Today, biological wastewater treatment is the main method used around the world. Given the urgency of the issue of water purification, for the construction of new stations it is recommended to combine the advantages of different methods and designs in order to obtain the best quality of water purification with maximum efficiency of the complex.

The first laboratory experiments on wastewater treatment with activated sludge date back to 1914 (E. Ardern and WT Lockett, Manchester). The first full-scale mechanical activated sludge aeration system was put into operation in 1921-1924 in the English city of Sheffield. By 1924, the total productivity of this system reached 88320 m ³ /day in wastewater. There was used the so-called Sheffield aeration system to oxygenate the water, which still stands today and is probably the world's oldest activated sludge sewage treatment plant still in operation. These aerotanks with a mechanical aeration system were equipped with a riveted forged aerator with a horizontal axis of rotation. When rotating, the aerator simultaneously performed two functions: 1 - introduction of atmospheric oxygen into the sludge mixture of the aeration tank; 2 - ensuring the necessary speed of circulation of the sludge mixture, about 0.5 m/s. Thus, one of the oldest flow-through aerotanks with suspended activated sludge was designed using longitudinal recirculation of the sludge mixture according to the "carousel" type.

For wastewater treatment, tower or shaft aerotanks are sometimes used, which have a more energy-efficient aeration system, which saves more than 2 times the energy consumed compared to traditional aerotanks. The prior art is known for the design of vertical aerotanks - facilities for biological wastewater treatment, which are vertical aerobic bioreactors, with an aeration depth of more than 9 meters, buried or above ground. For the first time, vertical aeration tanks began to be used in the 1980s of the last century in Germany, England and Canada. Companies such as Kubota, Hitachi and Mitsubishi built a significant number of shaft aeration tanks up to 130 m deep in Japan in the 1990s, due to the lack of urban areas for the location of treatment facilities.

In the USSR, tower and mine aerotanks have found their application for the treatment of industrial effluents with high concentrations of biochemical oxygen demand (hereinafter referred to as BOD). As a rule, tower aerotanks were divided into two parts. In the first, a pneumatic aeration system was installed, and in the second, an airlift or a propeller pump for circulating the sludge mixture. In the first part, a downward flow of the sludge mixture was created at a speed of 1.0 to 2.0 m/s, entraining air from the aerator to the lower part of the structure and increasing the residence time of air bubbles in the wastewater at elevated pressure in order to more effectively dissolve oxygen.

Abroad, tower and shaft aerotanks are used very actively, their effectiveness has been time-tested under various operating conditions. They are suitable for both manufacturing plants and urban areas where there is a need for cleaning, but there is a limited area for housing facilities. In 2000, a wastewater treatment plant "Golden Cheese" was introduced in the USA, which purifies heavily polluted wastewater from dairy production in the amount of 2650 m ³ / day with a BOD concentration of 2700 g / m ³ with pollution jumps up to 5 times with burst discharges and fluctuations pH 4 to 11. The treatment system based on vertical aeration tanks has resulted in significant savings in capital and operating costs, with a very small footprint - 1100 m ² , which is approximately 20% of the area of traditional facilities. The sludge concentration in vertical aeration tanks is up to 15 g/l. The load on the gravity desilter is 2 m ³ /(m ² ⋅h). The amount of exhaust gases is 5 to 10 times lower than that of traditional biological treatment plants. Specific energy consumption for oxygen transfer is from 0.3 to 0.5 kWh/kg.

So, as an analogue, we can cite an invention (patent for the invention US5650070A Pollock David) related to aerobic bioreactors and processes with a long vertical body, which is used for aerobic wastewater treatment and autothermal thermophilic aerobic sludge digestion.

This technical solution is made in the form of a vertical body, divided into two parts.

When the bioreactor is started, a mixture of air and incoming waste water is injected into the riser like an airlift pump. As soon as the circulation of the mixed biomass begins, air is injected into the downcomer. The medium in the riser has a higher density than the mixture of biomass and gas in the riser and thus provides sufficient lift to maintain circulation. The reaction between waste, dissolved oxygen, nutrients and biomass mainly occurs during circulation through the downcomer, riser and basin system of the bioreactor.

The main disadvantages of the technical solution is the complexity of manufacturing and the impossibility of organizing deep biological treatment from biogenic elements due to the lack of circulation of the sludge mixture between the aerobic, anaerobic and anoxic zones.

A technical solution is known from the prior art (patent for the invention SU1263651A1, Repin Boris Nikolaevich, 1986 according to IPC C02F3 / 12), made in the form of an aerotank containing a body divided by partitions into mixing chambers with mechanical aerators and circulation pipelines, a displacement chamber and reactivators, distribution and bypass trays. The aerotank is equipped with a trapezoidal chute located along the longitudinal axis of the aerotank and connected by its upper edges to the lower edges of the partitions of the reactivators, mixing and displacement chambers to form a tank for sludge collection, an airlift shaft made of vertical partitions.

The main disadvantages are the representation of the technical solution in the form of an open reservoir, which is characterized by significant heat losses in winter, the release of a large amount of harmful substances into the atmosphere and high energy consumption for aeration.

Known technical solution, presented in the form of a method of biological wastewater treatment (patent for invention SU1288165, Sinev Oleg Petrovich, Protsenko Sergey Borisovich, Romanov Yuri Alexandrovich, 1987 according to IPC C02F 3/02 (2000.01)), which presents a device containing aeration tank and shaft in which aeration takes place.

According to the biological wastewater treatment method, the mixture of treated water and activated sludge is aerated in an aeration tank. From the aeration tank, the mixture is withdrawn by a pump, mixed with an oxygen-containing gas, such as air, and fed in the form of a gas-liquid emulsion into the lower zone of the vertical shaft. Under the action of hydrostatic pressure, a part of the oxygen-containing gas is dissolved in the mixture. Undissolved gas, together with a part of the mixture, is removed in the form of a separate branch pipe from the upper zone of the mine to the lower zone of the aerotank.

The main disadvantage of the technical solution is the impossibility of organizing deep biological treatment from biogenic elements due to the lack of circulation of the sludge mixture between the aerobic, anaerobic and anoxic zones.

The closest analogue (prototype) is a technical solution made in the form of a block-modular wastewater treatment plant (patent for invention No. 2725262, Published: 30.06.2020 Bull. No. 19, according to IPC C02F 3/00, C02F 9/14).

The block-modular treatment facility has a sealed body consisting of separate collapsible unified structural blocks of pipes interconnected by turning sections and fittings, made in the form of at least one in-line, annular, horizontal, vertical or inclined tank using sealed connecting elements, swivel sections and fittings. The body contains in its volume a water-air mixture of activated sludge and sewage under excess pressure up to 36 atmospheres. The housing is equipped with a sewage or sludge mixture supply pipe, a sludge mixture or purified water discharge pipe, a sludge mixture aeration system, a sludge mixture movement stimulator, a gas-air mixture injection device, a gaseous emissions purification device, a sealed manhole for servicing process equipment, a recirculation pump sludge mixture.

The main disadvantages of this technical solution is the need to maintain in the volume of the block-modular structure the purification of the water-air mixture of activated sludge and wastewater under pressure up to 36 atmospheres. The presence of excess pressure complicates maintenance and increases the cost of manufacture.

The objective of the claimed invention is to eliminate the shortcomings of analogues and the prototype, and the technical result is to reduce the amount of emissions of gaseous substances into the atmosphere, to manufacture a reservoir in the form of various technological schemes for deep biological wastewater treatment from biogenic elements, to reduce the size of structures, and to increase the efficiency of absorbing oxygen from the air, increase in the oxidizing capacity of the treatment plant, respectively, with reduced energy consumption by 40-60%.

The set technical result is achieved due to the fact that
carousel aeration tank with a buried shaft, characterized in that it has a body consisting of separate collapsible unified structural blocks interconnected by turning sections and fittings, made in the form of at least one annular tank using sealed connecting elements, turning sections and fittings , containing in its volume a water-air mixture of activated sludge and waste water, the body is equipped with a branch pipe supplying sewage or sludge mixture, a branch pipe draining the sludge mixture or purified water, at least one buried shaft with a system of aeration of the sludge mixture, at least one stimulator movement of the sludge mixture.

In this case, the body may contain at least one anoxic zone.

In this case, the housing may contain at least one anaerobic zone.

In this case, the blocks can be made of precast concrete products.

In this case, the blocks can be made of prefabricated plastic products.

In this case, the blocks can be made of prefabricated metal products.

At the same time, the body may consist of separate prefabricated unified structural blocks made of pipes made of composite material: glass-composite, carbon fiber, boron-plastic, organoplastic, polymer, filled with powders, textolite and others.

At the same time, the body may consist of separate prefabricated unified structural blocks made of reinforced concrete pipes with a core of glass composite or other composite material.

At the same time, the body may consist of separate prefabricated unified structural blocks made of metal pipes with a lining of inert material.

In this case, detachable coupling joints made of glass composite or other composite material and equipped with elastic sealing elements can act as hermetic connecting elements.

In this case, detachable coupling joints made of steel and equipped with elastic sealing elements can act as hermetic connecting elements.

In this case, detachable flange connections can act as hermetic connecting elements.

In this case, one-piece welded or adhesive joints can act as hermetic connecting elements.

In this case, one-piece laminated joints can act as hermetic connecting elements.

In this case, coupling joints can act as hermetic connecting elements.

In this case, the motion stimulator can be made in the form of a mechanical stirrer.

In this case, the motion stimulator can be made in the form of an ejector.

In this case, the motion stimulator can be made in the form of an airlift.

In this case, the motion stimulator can be made in the form of a submersible pump.

In this case, the aeration system can supply a gas-air mixture enriched with carbon dioxide and/or oxygen.

In this case, the aeration system can use a pneumatic method of dissolving gases.

In this case, the aeration system can use a mechanical method of dissolving gases.

In this case, the aeration system can use the ejector method of dissolving gases.

In this case, the aeration system can use the airlift method of dissolving gases.

At the same time, the body can be equipped with at least one grate, at least one sand trap, at least one settling tank, at least one desilter, at least one acidifier, at least one aerobic sludge stabilizer, at least at least one methane tank, at least one flotation tank, at least one membrane filtration module, used both in combination and separately.

The claimed invention is illustrated by the following drawings:

On FIG. Figure 1 shows one of the variants of the carousel aeration tank with a buried shaft with an implemented scheme of deep biological treatment due to the recirculation of the sludge mixture through zones with different oxygen regimes: anaerobic, acanthic and aerobic.

On FIG. 2 shows a carousel aerotank with a buried shaft,

section A-A.

On FIG. 3 shows a carousel aerotank with a buried shaft,

cut B-B.

Where:

1) body;

2) hermetic connecting elements;

3) a branch pipe supplying sewage or sludge mixture;

4) outlet sludge mixture or purified water branch pipe;

5) sludge mixture aeration system;

6) activator of the movement of the sludge mixture;

7) pump for recirculation of the sludge mixture;

8) air duct for supplying the gas mixture;

9) buried mine;

10) feed return activated sludge branch pipe;

11) hatch for maintenance of technological equipment;

12) turning sections;

13) fittings.

Rotary aerotank with a buried shaft, characterized in that it has a body (1) consisting of separate collapsible unified structural blocks interconnected by rotary sections (12) and fittings (13), made in the form of at least one annular tank with using hermetic connecting elements (2), swivel sections (12) and fittings (13), containing in its volume a water-air mixture of activated sludge and waste water, the body (1) is equipped with a sewage or sludge mixture supply pipe (3), which discharges sludge mixture or purified water with a branch pipe (4), at least one deep shaft (9) with a sludge mixture aeration system (7), a sludge mixture movement stimulator (6), a device for cleaning gaseous emissions, a sealed hatch for servicing process equipment (11) , a pump for recirculation of the sludge mixture (7), which can be made in different variations, for example, in the form of a snake, several rings, etc.

In this case, the housing (1) may contain at least one anoxic zone.

In this case, the housing (1) may contain at least one anaerobic zone.

In this case, the blocks can be made of precast concrete products.

In this case, the blocks can be made of prefabricated plastic products.

In this case, the blocks can be made of prefabricated metal products.

In this case, the body (1) may consist of separate prefabricated unified structural blocks made of pipes made of composite material: glass-composite, carbon fiber, boron-plastic, organoplastic, polymer, filled with powders, textolite and others.

In this case, the housing (1) may consist of separate prefabricated unified structural blocks made of reinforced concrete pipes with a core of glass composite or other composite material.

In this case, the body (1) may consist of separate collapsible unified structural blocks made of metal pipes with a lining of inert material.

In this case, detachable coupling joints made of glass composite and equipped with elastic sealing elements can act as hermetic connecting elements (2).

In this case, detachable coupling joints made of steel and equipped with elastic sealing elements can act as hermetic connecting elements (2).

In this case, detachable flange connections can act as hermetic connecting elements (2).

In this case, one-piece welded or adhesive joints can act as hermetic connecting elements (2).

In this case, one-piece laminated joints can act as hermetic connecting elements (2).

In this case, coupling joints can act as hermetic connecting elements (2).

In this case, the activator of the movement of the sludge mixture (6) can be made in the form of a mechanical mixer.

In this case, the activator of the movement of the sludge mixture (6) can be made in the form of an ejector.

In this case, the activator of the movement of the sludge mixture (6) can be made in the form of an airlift.

In this case, the driving force of the sludge mixture (6) can be made in the form of a submersible pump.

In this case, the aeration system (5) can supply a gas-air mixture enriched with carbon dioxide and/or oxygen.

In this case, the aeration system (5) can use the pneumatic method of dissolving gases.

In this case, the aeration system (5) can use the mechanical method of dissolving gases.

In this case, the aeration system (5) can use the ejector method of dissolving gases.

In this case, the aeration system (5) can use the airlift method of dissolving gases.

In this case, the housing (1) can be equipped with at least one grate, at least one sand trap, at least one settling tank, at least one desilter, at least one acidifier, at least one aerobic sludge stabilizer, at least one methane tank, at least one flotation tank, at least one membrane filtration module, used both in combination and separately.

The device works as follows.

The housing (1) consists of separate collapsible unified structural blocks interconnected by sealed connecting elements (2), rotary sections (12) and fittings (13), and is also equipped with a deep shaft (9) with an aeration system (5). The body (1) is made in the form of at least one annular tank using, if necessary, rotary sections (12) and fittings (13) connecting two or more unified structural blocks.

Waste water enters through the supply pipe (3), equipped, if necessary, with shut-off and control valves, a grate, a sand trap, used both in combination and separately, inside the sealed housing (1). The housing (1) contains in its volume a water-air mixture of activated sludge and waste water. The flow of the sludge mixture inside the structure, if necessary, is provided by a sludge mixture movement driver (6) and a pump for recirculating the sludge mixture (7).

Further, wastewater mixed with activated sludge enters a buried shaft (9) with an aeration system (5), which is a vertical, horizontal or inclined buried shaft (9). The parameters of the buried shaft (9) depend on the calculated characteristics of the rotary aerotank. The aeration system (5) is a system of air ducts for supplying a gas mixture (8), through which gas is supplied to the bottom of a buried mine (9), diffusers designed to enrich the mixture of wastewater and activated sludge with gas. The most effective aeration of the mixture of waste water and activated sludge is carried out in the lower part of the buried mine (9). It is there that the greatest saturation of the mixture of activated sludge and wastewater with gas occurs, due to an increase in pressure. A water-air mixture of activated sludge and wastewater is formed. Having passed the zone of deep aeration, the water-air mixture of activated sludge and wastewater rises from the buried shaft (9) and continues to circulate in the system.

Due to the supply and disposal of wastewater, aeration, mixing and recirculation of the sludge mixture inside the housing (1), zones with different oxygen regimes are created: anaerobic, acanthic, aerobic and others necessary for biological wastewater treatment. Thus, one treatment cycle includes the passage of a water-air mixture of activated sludge and wastewater through a deep mine (9) with an aeration system (5), anaerobic, axoxic and other zones necessary for deep biological wastewater treatment. At the same time, the zones can be equipped with a grate, a sand trap, a sedimentation tank, a desilter, an acidifier, an aerobic sludge stabilizer, a digester, a flotator, a membrane filtration module, a device for cleaning gaseous emissions, used both in aggregate and separately, in the amount necessary to ensure deep biological wastewater treatment.

The presence of an annular aerotank with at least one buried shaft (9) allows you to repeat the wastewater treatment process continuously and cyclically. At the same time, if necessary, the water-air mixture of activated sludge and wastewater can go through any number of cleaning cycles until the required level of deep biological treatment is achieved. Purified water or sludge mixture is discharged through the outlet pipe (4), equipped, if necessary, with shut-off and control valves, grate, sand trap, both in aggregate and separately.

Maintenance of technological equipment is carried out by a sealed hatch (11).

The presence of several rotary aerotanks with a buried shaft, presented in the form of a single system of deep biological wastewater treatment, will allow for maintenance and repair, or the replacement of some structural unified blocks, without stopping the cleaning process, by turning off one of the buildings (1) of the rotary aerotanks with a buried mine (9) and redistribution of the wastewater flow.

An example of a technical solution in the form of a carousel aeration tank with a deep shaft with an aeration system according to one of the embodiments of the invention is a body made in the form of a carousel aeration tank, consisting of separate collapsible unified structural blocks made of glass composite pipes.

The hull has six recessed shafts with pneumatic aeration systems made of the same material as the hull. Each buried shaft is made in the form of a vertical pipe connected to the housing by a hermetic connection. The blocks are interconnected by hermetic connecting elements and fittings. Detachable coupling joints made of glass composite and equipped with elastic sealing elements act as hermetic connecting elements.

The body is equipped with two supply sewage, two return activated sludge supply, two sludge mixture outlet branch pipes. The body is made in the form of four annular tanks. The housing contains ten mechanical agitators, two submersible pumps, two grids, two sand traps, two membrane filtration modules. The pneumatic aeration system of a buried mine contains two blowers of the gas mixture, a system of air ducts with disk aerators. The exhaust air passes through an exhaust gas treatment device. A mixture of wastewater and activated sludge circulates between different zones of biological treatment: aerobic, anaerobic, anoxic. Purified wastewater is discharged through the outlet sludge mixture or purified water branch pipe. Installation of technological equipment is carried out through service hatches.

Claims (26)

1. Rotary aerotank with a deep mine, characterized in that it has a body consisting of separate collapsible unified structural blocks interconnected by sealed connecting elements and fittings, containing at least one aerobic zone, at least one supply pipe, at least one discharge branch pipe, at least one motion stimulator, characterized in that the body is made in the form of at least one annular reservoir and contains at least one buried shaft with an aeration system. 2. Carousel aerotank with a buried shaft according to claim 1, characterized in that the body contains at least one anoxic zone. 3. Carousel aeration tank with a buried shaft according to claim 1, characterized in that the body contains at least one anaerobic zone. 4. Rotary aerotank with a buried shaft according to claim 1, characterized in that the blocks are made of precast concrete products. 5. Carousel aeration tank with a deep shaft according to claim 1, characterized in that the blocks are made of prefabricated plastic products. 6. Carousel aerotank with a buried shaft according to claim 1, characterized in that the blocks are made of prefabricated metal products. 7. Rotary aerotank with a buried shaft according to claim 1, characterized in that the body consists of separate prefabricated unified structural blocks made of pipes made of composite materials. 8. Rotary aerotank with a buried shaft according to claim 1, characterized in that the body consists of separate prefabricated unified structural blocks made of reinforced concrete pipes with a core of glass composite or other inert material. 9. Rotary aerotank with a buried shaft according to claim 1, characterized in that the body consists of separate prefabricated unified structural blocks made of metal pipes lined with an inert material. 10. Rotary aerotank with a buried shaft according to claim 1, characterized in that coupling joints act as hermetic connecting elements. 11. Rotary aerotank with a buried shaft according to claim 1, characterized in that detachable coupling joints made of glass composite and equipped with elastic sealing elements act as hermetic connecting elements. 12. Rotary aerotank with a buried shaft according to claim 1, characterized in that detachable coupling joints made of steel and equipped with elastic sealing elements act as hermetic connecting elements. 13. Rotary aerotank with a buried shaft according to claim 1, characterized in that detachable flange connections act as sealed connecting elements. 14. Rotary aerotank with a buried shaft according to claim 1, characterized in that one-piece welded or adhesive joints act as sealed connecting elements. 15. Rotary aerotank with a buried shaft according to claim 1, characterized in that one-piece laminated joints act as hermetic connecting elements 16. Carousel aerotank with a deep shaft according to claim 1, characterized in that the movement stimulator is made in the form of a mechanical stirrer. 17. Carousel aeration tank with a deep shaft according to claim 1, characterized in that the movement stimulator is made in the form of a submersible pump. 18. Carousel aeration tank with a buried shaft according to claim 1, characterized in that the movement stimulator is made in the form of an ejector. 19. Carousel aeration tank with a buried shaft according to claim 1, characterized in that the movement stimulator is made in the form of an airlift. 20. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system supplies a gas-air mixture enriched with carbon dioxide. 21. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system supplies a gas-air mixture enriched with oxygen. 22. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system uses a pneumatic method of dissolving gases. 23. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system uses a mechanical method of dissolving gases. 24. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system uses the ejector method of dissolving gases. 25. Rotary aerotank with a buried shaft according to claim 1, characterized in that the aeration system uses the airlift method of dissolving gases. 26. Rotary aerotank with a buried shaft according to claim 1, characterized in that the body is equipped with at least one grate, at least one sand trap, at least one settling tank, at least one desilter, at least one acidifier , at least one aerobic sludge stabilizer, at least one digester, at least one flotation tank, at least one membrane filtration module, at least one gaseous emission purification device, used both in combination and separately.

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