CN113045075B

CN113045075B - Gas dissolving system, gas dissolving method and sewage treatment system

Info

Publication number: CN113045075B
Application number: CN202110318305.7A
Authority: CN
Inventors: 罗军杰; 罗林; 吕策; 庞汝林; 李清楠
Original assignee: Qinhuangdao Tonglida Environmental Energy Engeneering Co ltd
Current assignee: Qinhuangdao Tonglida Environmental Energy Engeneering Co ltd
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2022-07-29
Anticipated expiration: 2041-03-25
Also published as: CN113045075A

Abstract

The invention provides a gas dissolving system, a gas dissolving method and a sewage treatment system aiming at the technical problem of lower gas dissolving efficiency of a gas dissolving device for air floatation in the prior art, the gas dissolving system comprises a sealed tank body, a water outlet is arranged on the tank body, at least two gas dissolving areas are arranged in the tank body, the gas dissolving areas comprise a gas dissolving water area and a specific surface area increasing area, the specific surface area increasing area is arranged above the gas dissolving water area, the sewage treatment system comprises an air floatation device, a filtering system and the gas dissolving system, an air-float releaser is arranged between the water outlet of the air-dissolving system and the water inlet of the air-float device, the air-dissolving method is that water meets high-pressure gas after the specific surface area is increased to form air-dissolving water, and then the air is dissolved again by the aerator. High dissolving efficiency, high gas utilization rate and small bubbles, so that the air floatation effect is good.

Description

Gas dissolving system, gas dissolving method and sewage treatment system

Technical Field

The invention relates to the technical field of sewage treatment, in particular to an air dissolving system, an air dissolving method and a sewage treatment system.

Background

The air floatation technology is that a large amount of highly dispersed micro-bubbles are introduced into water to be treated, the micro-bubbles are used as carriers and adhered with particles or floccules suspended in the water to form a floating body with the integral density smaller than that of the water, the suspended matters float to the water surface under the buoyancy action of the water, and the floating body is removed after floating slag is formed, so that the separation of the particles or the floccules in the water from the water is completed. Wherein, the gas dissolving device is adopted to release water containing gas with certain pressure into the liquid to be treated, namely gas dissolving water, thereby generating micro bubbles. At present, the air floatation equipment is widely used in the sewage treatment industry and is specially used for removing suspended matters and oil in sewage. The air-floating air-dissolving system is used for generating certain micro-bubbles which are combined with suspended matters and oil in sewage and used as carriers of the suspended matters and the oil to float upwards so as to achieve the purpose of separating water from the suspended matters and the oil. A conventional pressurized gas dissolving system generally includes a large gas dissolving tank body 1, a water pump 6 and an air compressor 7 (as shown in fig. 1), wherein a filler 9 is filled in the gas dissolving tank body 1. Water and air enter the dissolved air tank body 1 through the water inlet rotational flow body 5 and the air inlet pipe 4 respectively at the same time, stay in the dissolved air tank body for 3-5 minutes, the liquid volume does not exceed 2/3 of the volume of the dissolved air tank generally, the internal pressure is 0.4mPa generally, and the air is firstly dissolved in the water to form so-called dissolved air water. When the gas-dissolved water is mixed with raw water, the pressure is reduced, and the solubility is reduced, so that air is released from the gas-dissolved water and is used as a carrier of suspended matters and oil to float, and the purpose of separating water from the water is achieved. The bubbles are generally 90-80 μm, the effect is good, and the system is a typical traditional dissolved air system. The gas dissolving system adopting the structure needs to adopt a gas dissolving tank with a relatively large volume, and the pressure of gas in the gas dissolving tank is large because micro bubbles are formed, so that the gas dissolving tank forms a pressure container, and the cost is very high.

In order to solve the technical problems, the Chinese patent with the publication number of CN2652916Y and the name of a rotational flow air dissolving device discloses a rotational flow type air dissolving tank, wherein a rotational flow air dissolving pipe is adopted as an air dissolving tank body, one or more cavities are arranged on the inner wall of the rotational flow air dissolving pipe, a microporous plate is arranged at the outlet of each cavity, and the inlet of each cavity is connected with the outlet of an air compressor through an air inlet pipe; the water inlet rotational flow body adopts a tangential water inlet rotational flow body; the air dissolving device has simple structure, but also has the problem of low air dissolving efficiency.

In addition, in the prior art, the quartz sand filter tank is adopted to filter sewage, while suspended matters in water are effectively removed, the quartz sand filter tank also has obvious removing effect on pollutants such as colloid, iron, organic matters, pesticides, manganese, bacteria, viruses and the like in water, but because the bubbles of inlet water are large and the air content is low, the quartz sand filter tank has the following problems that the quartz sand filter tank has certain limit on the oil content of inlet water, when the oil content of inlet water exceeds a limited range, the operation period of the filter tank is shortened, the filtering capability is reduced, filter plates in the filter tank are easy to harden and form ball mud, when backwashing is carried out, the inlet water in the filter tank is stopped to treat sewage, the load of other filter tanks is increased, the water quality of outlet water is influenced, in addition, in order to solve the problem of high oil content in inlet water, special oil removing equipment is usually added in front of the quartz sand filter tank to increase the occupied area, the management cost is increased, and therefore, the sewage treatment of the water containing a large amount of oil cannot be efficiently performed by the apparatus of the prior art.

Disclosure of Invention

The invention aims to provide an air dissolving system, an air dissolving method and a sewage treatment system, aiming at the technical problem that the air dissolving efficiency of an air dissolving device for air floatation in the prior art is low.

The purpose of the invention is realized by the following technical scheme:

the gas dissolving system comprises a sealed tank body, a water outlet is arranged on the tank body, at least two gas dissolving areas are arranged in the tank body, the gas dissolving areas comprise a gas dissolving water area and a specific surface area increasing area, the specific surface area increasing area is arranged above the gas dissolving water area, an aerator is arranged in the gas dissolving water area, the gas outlet end of the aerator is arranged in the tank body and is positioned in the gas dissolving water, the gas inlet end of the aerator is arranged outside the tank body and is communicated with the gas outlet of the high-pressure gas supply device, a specific surface area increasing device is arranged in the specific surface area increasing area, a water inlet is arranged on the tank body and corresponds to the specific surface area increasing device, water is increased in the specific surface area by the specific surface area increasing device and is dissolved with high-pressure gas and then falls into the gas dissolving water area, and the water outlet is connected with the gas dissolving water area; a low water level monitor and a high water level monitor are arranged above the gas-dissolved water area, the low water level monitor and the high water level monitor are respectively in electric signal connection with an electromagnetic valve arranged on the gas inlet, when the water level is higher than the upper water level limit, the electromagnetic valve is opened to charge gas into the tank body, and when the water level is lower than the lower water level limit, the electromagnetic valve is closed;

The specific surface area increasing device arranged in the specific surface area increasing area comprises a packed bed, the packed bed is fixedly connected with the tank body, the packed bed is provided with a filler, and the water inlet is positioned above the filler;

the specific surface area increasing device arranged in the specific surface area increasing area comprises an upper plugging plate, a lower plugging plate and a plurality of cyclones, wherein the upper plugging plate and the lower plugging plate are fixedly connected with the tank body, a containing cavity for containing the cyclones is formed in the tank body, each cyclone comprises a pipe body, a plurality of tangential small holes are formed in the pipe body, the tangential small holes are spirally arranged along the axial direction of the pipe body, the upper end and the lower end of each pipe body are respectively and fixedly connected with the upper plugging plate and the lower plugging plate in a sealing mode, the upper end and the lower end of each pipe body are respectively opposite to through holes formed in the upper plugging plate and the lower plugging plate, the pipe body is communicated with the inner cavity of the tank body through the through holes, and the water inlet is positioned between the upper plugging plate and the lower plugging plate;

the specific surface area increasing area comprises a cyclone subarea and a filler area, the cyclone subarea is positioned above the filler area, the specific surface area increasing device arranged in the cyclone subarea comprises an upper plugging plate, a lower plugging plate and a plurality of cyclones, the cyclones comprise a pipe body, a plurality of tangential small holes are arranged on the pipe body, the tangential small holes are spiral along the axial direction of the barrel, the upper plugging plate and the lower plugging plate are respectively and fixedly connected with the inner wall of the tank body, the upper plugging plate, the lower plugging plate and the corresponding tank body form a containing cavity for containing the cyclones, two ends of the pipe body are respectively and correspondingly connected with the upper plugging plate and the lower plugging plate and correspond to through holes arranged on the upper plugging plate and the lower plugging plate, the pipe body is communicated with the inner cavity of the tank body through the through holes, and the water inlet is positioned between the upper plugging plate and the lower plugging plate; the specific surface area increasing device arranged in the filler area comprises a filler bed, the filler bed is fixedly connected with the inner wall of the tank body, the filler is arranged on the filler bed, and the filler bed is positioned above the gas-dissolved water area;

A space for mixing water and gas is arranged between the cyclone subarea and the filler area;

the water inlet is a tangential water inlet.

The utility model provides a sewage treatment system, includes air supporting device, filtration system and foretell air dissolving system, is provided with the air supporting releaser between the delivery port of air dissolving system and the water inlet of air supporting device, and the air dissolving water that the air dissolving system produced releases in the air supporting pond through the air supporting releaser, filtration system's filtering ponds set up the below at the air supporting pond, the filtering ponds comprise a plurality of filter check, and the water inlet of every filter check is respectively through the water purification play water end intercommunication of a raceway and air supporting pond, all is provided with the valve on each raceway.

A method for dissolving gas, water meets high-pressure gas after increasing the specific surface area to form gas-dissolved water, and then dissolves gas again through an aerator;

the water is dissolved with the high-pressure gas to form first-stage gas-dissolving water after the specific surface area is increased for the first time, the first-stage gas-dissolving water is dissolved with the high-pressure gas to form second-stage gas-dissolving water after the specific surface area is increased again, and the second-stage gas-dissolving water is aerated to dissolve gas again to form third-stage gas-dissolving water; the rotational flow body is adopted to carry out rotational flow on water to increase the specific surface area of air and water and/or the filler is adopted to increase the specific surface area of air and water;

The swirling water forms an interwoven water column through secondary swirling of the swirling flow, the interwoven water column forms jets in different directions to mutually collide with each other and collide with the inner wall of the swirling flow pipe body to form water mist, the water mist is dissolved with high-pressure gas by increasing the specific surface area of the gas water to form the primary gas-dissolving water, the primary gas-dissolving water is dissolved with the high-pressure gas to form secondary gas-dissolving water after increasing the specific surface area of the gas water through a filler, and the primary gas-dissolving water is sprayed to a filler area after being mixed with the water gas to obtain the secondary gas-dissolving water.

By adopting the spiral-flow type air-floating air-dissolving device provided by the invention, high-pressure water enters the spiral-flow body along the tangential direction, a rotational flow is formed between the upper plug and the lower plug, the upper plug and the lower plug move downwards under the action of gravity to form a water film, the water film meets high-pressure gas in the rotational flow body and is cut into fine water columns, the fine water columns tangentially enter the tube body of the rotational flow body through tangential small holes arranged on the tube body to form the rotational flow, because the small holes are spirally arranged downwards along the axial direction of the pipe body and each small hole is tangential, water entering the pipe body from the tangential small holes forms water columns in different directions and is interwoven with each other and collides with the inner wall of the pipe body at the same time, therefore, water mist is formed in the pipe body, when the water mist meets high-pressure gas entering from the openings at the upper end and the lower end of the pipe body, since the water film is formed to increase the specific surface area of water and gas, a large amount of gas can be dissolved to form relatively fine bubbles.

The gas dissolving system is provided with the specific surface area increasing area and the gas-dissolved water area, the specific surface area increasing area enables water to be fully contacted with high-pressure air entering the cylinder, so that the gas dissolving amount of the water is increased, meanwhile, the gas-dissolved water with the increased gas dissolving amount falls into the gas-dissolved water area and is further dissolved by the aerator, and the gas contained in the gas-dissolved water is more than that of the gas-dissolved water obtained by first-stage gas dissolving, so that bubbles generated after aeration by the aerator are small, and micro bubbles can also be obtained.

Further, the water is subjected to gas dissolving treatment by adopting three-stage dissolved gas, the water firstly enters an upper plugging plate and a lower plugging plate in a tangential rotational flow manner, rotational flow is formed in the rotational flow body along the inner wall of the tank body and flows downwards under the action of gravity, the water entering the rotational flow body is high-pressure water, meets with the pipe body of the rotational flow body in the rotational flow body and enters the pipe body of the rotational flow body in a tangential manner from water inlet holes arranged along a spiral line, on one hand, the water flows downwards along the inner wall of the rotational flow body to form a water film, on the other hand, the water is sprayed from the water inlet holes to enter the pipe body of the rotational flow body to form rotational flow water columns which are mutually interwoven to form jet flows in different directions and fully contact with the high-pressure gas entering the pipe body, the gas film is dispersedly formed by rotational flow under the action of the high-pressure gas, the specific surface area of the water and the gas is increased to form primary dissolved gas, the water is sprayed from the pipe body of the rotational flow body to flow to pass through a filler section to be mixed with the filler, the water permeates into gaps among the fillers to increase the contact area of the water and the air, the specific surface area is also increased, the combination of the air and water molecules is strengthened again, the air dissolving rate is improved to finish secondary air dissolving, the aerator is arranged in an air-water dissolving area, micro bubbles are formed under the action of the aerator, the air is dissolved in the water and the air is dissolved twice, therefore, the bubbles generated during aeration are small, the pressure gas which is not completely dissolved rises to a filler section and is partially dissolved into the air-dissolved water when meeting the air-dissolved water in the filler section, the water is increased in the filler section by the contact area of the water and the air, therefore, the gas dissolving amount is large, the gas which is not dissolved enters a cyclone subsection to be further dissolved with jet flow of the cyclone subsection, the air is circulated and dissolved by the third stage, the utilization rate of the compressed air is obviously improved, the air dissolving effect is enhanced, the power loss is small, the dissolved gas can be dissolved twice more, so that the dissolving efficiency is high, the gas utilization rate is high, the bubbles are small, and the air floatation effect is good.

The sewage treatment system combines the air floating device and the filtering device together, the air floating device is positioned above the filtering tank to form a three-dimensional structure which is arranged up and down, so the occupied space is small, the air dissolving water obtained by multi-stage air dissolving treatment is filled in the air floating tank, the multi-stage air dissolving water forms high-dispersion micro bubbles after entering the air floating tank, and the micro bubbles are easily combined with oil to form good oil residue floatability, are easy to be scraped by a slag scraping machine, reduce the load of the filtering tank, and are not easy to cause the hardening of filter materials and ball mud.

By adopting the gas dissolving method provided by the invention, water is dissolved with gas after the specific surface area of the gas and the water is increased, and then aeration is carried out, so that more dissolved gas is obtained, and the obtained bubbles are more tiny, thereby being beneficial to air floatation;

furthermore, after the specific surface area of the water is increased for the first time and then dissolved with the gas, the specific surface area of the water is increased again, and the specific surface area is increased after the water is dissolved with the gas for many times, so that the gas-water contact is more sufficient, and the gas dissolving effect is better.

Furthermore, the rotational flow body is combined with three-level dissolved air of dissolved air, filler dissolved air and aeration dissolved air, the rotational flow body is dissolved with air after increasing the specific surface area, then the specific surface area is increased by the filler, and the viscosity of water in the filler area is broken by the air again, so that the capacity of dissolving the air is enhanced, the dissolved air is more, the bubbles generated by the obtained dissolved air water are small, micro bubbles are generated, and the air floatation is facilitated.

Drawings

FIG. 1 is a schematic view of a prior art air dissolving apparatus;

FIG. 2 is a schematic diagram of an embodiment of the air dissolving system of the present invention;

FIG. 3 is a schematic view of the view from direction A of FIG. 2;

FIG. 4 is a schematic view of the position of the pipe body and the small hole when the pipe body is provided with tangential small holes;

FIG. 5 is a schematic structural view of an embodiment of a filtration system in the wastewater treatment system of the present invention (the structures of the air flotation device except the air flotation tank are not shown);

FIG. 6 is a schematic structural view of an embodiment of a filtering apparatus in a sewage treatment system according to the present invention (one of the sub-tanks is removed, and one of the filter media beds in the sub-tank is hidden);

FIG. 7 is a schematic structural view of an embodiment of a filter grid in the sewage treatment system of the present invention;

FIG. 8 is a schematic cross-sectional view of a filter cell of a filter assembly of the present invention in a wastewater treatment system at a drain channel and an air distribution channel.

Description of the reference numerals

110-a filtration tank; 111-an air inlet; 112-a water purification port; 113-a sewage draining outlet; 114-a water inlet; 115-a separation tank body; 120-filter lattice; 121-water distribution weir; 122-drainage channels; 123-gas water distribution channel; 124-filter material bed; 125-water purification area; 126-air distribution holes; 127-water distribution hole; 128-water distribution holes; 129-raw water zone; 130-inclined plate;

200-an air floatation tank;

300-water conveying pipe; 301-valve.

6-gas-dissolved water area 7-filling area 8-cyclone subarea 9-tank body

601-aerator

701-packed bed 702-packing

801-cyclone 802-helix 803-small hole 804-pipe body 805-upper plugging plate 806-lower plugging plate 807-through hole

901-air inlet 902-air outlet 903-water inlet 904-hand hole 905-liquid level meter interface I906-liquid level meter interface II 911-water outlet 914-inspection port 915-water-air mixing section 916-tank seat

Detailed Description

The invention is further described below with reference to specific examples:

as shown in fig. 2-4, the air dissolving system provided by the present invention comprises a sealed air dissolving tank, wherein the upper end of the tank body 9 is a specific surface area increasing zone, the lower end is an air dissolving water zone 6, and an aerator 601 is arranged in the air dissolving water zone. The air dissolving system of the invention is particularly suitable for air floatation.

The dissolved air water area 6 is provided with an aerator 601, an air inlet 901 is arranged on the tank body and is communicated with the air inlet end of the aerator, and the air outlet end of the aerator is positioned in the tank body. The air inlet 901 of the aerator is communicated with the air outlet of the air compressor. The aerator is preferably an aerator pipe, and particularly preferably a microporous aerator pipe. The microporous aeration pipe is preferably formed by coating a stainless steel pipe with a micro-bubble membrane, also called microporous membrane, to form the aeration pipe. The axial direction of the aeration pipe is preferably arranged in the same direction as the radial direction of the tank body. At least the air outlet end of the aerator is positioned in the dissolved air water. On the tank body corresponding to the dissolved air water area, a water outlet 911 is preferably arranged below the tank body, and the dissolved air water enters the air floating device from the water outlet. For the convenience of operation, the water outlet of the air dissolving system is arranged outside the tank body seat 916 through a pipeline, and preferably, a hand hole 904 is arranged on the tank body and is positioned on the tank body 9 between the cyclone sub-area 8 and the filling area 7.

The specific surface area increasing area can be a cyclone sub-area 8 or a packing area 7, and can also be simultaneously provided with the cyclone sub-area and the packing area, wherein the specific surface area increasing area is an independent cyclone sub-area or packing area to form secondary dissolved air, and if the specific surface area increasing area is simultaneously provided with the packing area and the cyclone sub-area, tertiary dissolved air is formed. The following description will be made separately.

In the invention, a cyclone subarea 8 with a structure is preferentially adopted, which is provided with a plurality of cyclones 801, each cyclone comprises a pipe body 804, a plurality of small holes 803 are arranged on the pipe body, the small holes are distributed on the pipe body along a spiral line 802, actually, no spiral line exists on the pipe body, the hole centers of the small holes are positioned on an imaginary spiral line, the hole center lines of the small holes are arranged along the tangential direction of the pipe wall and have a certain distance B according to the center line of the pipe wall, the small holes are called tangential small holes, the cyclone subarea 8 is provided with an upper plugging plate 805 and a lower plugging plate 806, the upper plugging plate 805 and the lower plugging plate 806 are fixedly connected with the inner side wall of the tank body in a sealing way, through holes 807 are respectively arranged at the corresponding positions on the upper plugging plate and the lower plugging plate, the plurality of cyclones 801 are vertically arranged between the upper plugging plate and the lower plugging plate in parallel, and the number and the positions of the through holes 807 correspond to the number and the positions of the pipe bodies of the cyclones, the diameter of the through hole is consistent with the inner diameter of the pipe body or smaller than the inner diameter of the pipe body, the upper end and the lower end of each cyclone are fixedly connected with the upper plugging plate and the lower plugging plate in a sealing mode respectively, a gap between the two ends of the pipe body of each cyclone is sealed by the upper plugging plate and the lower plugging plate, a water inlet 903 is formed in the tank body 9, the hole center line of the water inlet 903 is arranged along the tangential direction of the wall of the tank body and is a tangentially arranged water inlet, the water inlet is located between the upper plugging plate and the lower plugging plate, the tank body between the upper plugging plate and the lower plugging plate and the tangential water inlet 903 form a cyclone body, and the water inlet 903 is communicated with a water outlet of the water pump. Adopt the whirl subregion 8 of above-mentioned structure, water enters into the whirl with the whirl tangent line from water inlet 903 and meets the dispersion with high-pressure gas and becomes tiny water column, in getting into the body 804 of every whirl son from the aperture whirl tangent line, because the high pressure water enters into the body in from the tangential aperture and the aperture distributes along the helix, consequently at the internal whirl that has formed of body, jet the water column that enters into the interweaving in the body 804 from aperture 803 forms the jet impact each other of equidirectional not and strikes the pipe wall simultaneously and forms water smoke, carry the water film that forms the area gas by the whirl, with the high-pressure air fully contact who enters into the body, specific surface area has been increased, can contact with the air more fully and dissolve mutually, increase the gas dissolving effect, form the gas dissolving water. The dissolved air water is sprayed out from the lower opening of the tube body, i.e., the through hole 807, under the action of pressure and gravity.

The invention preferentially adopts a packing area 7 with the following structure, a packed bed 701 and a packing 702 are arranged in the packing area 7, the packed bed is fixedly connected with the inner side wall of the tank body, and the packing 702 is positioned on the packed bed 701.

When the specific surface area increasing area is a cyclone subarea to form a secondary gas dissolving structure, the cyclone subarea is positioned below the gas-water dissolving area, and gas-water dissolving water sprayed from the tube body of the cyclone enters the gas-water dissolving area. Preferably, level meters are arranged in the cyclone subarea and the gas-dissolved water area to detect the liquid level condition of the gas-dissolved water area.

When the specific surface area-increasing region is a packed region, the following structure is preferably employed: a packed bed 701 is arranged in the tank body 9 of the dissolved air tank and above the dissolved air water area 6, the packed bed is fixedly connected with the inner wall of the tank body 9, the packed bed 701 is provided with a filler 702, the part of the tank body above the filler is provided with a water inlet 903, the water inlet 903 is preferably a tangential water inlet, water enters the tank body from the water inlet and falls between the fillers, the specific surface area of the air and the water is increased by the filler, the water is directly contacted with the air, the air is dissolved in the water, the air generates viscosity after being dissolved in the water due to the surface tension of the water, one part of the high-pressure air entering the air dissolving tank from the aerator is dissolved with the water, the other part of the high-pressure air rises to meet the water spread among the fillers, cutting water to disperse the water, the water dispersed by high-pressure gas is more soluble with gas, so the gas-soluble amount is increased, meanwhile, the dissolved air water with increased dissolved air amount falls into the dissolved air water area 6 and is further dissolved by the aerator 601.

When the specific surface area increasing area is a rotational flow subzone, the following structure is preferentially adopted: the dissolved air water area 6 is located below the lower plugging plate, the rotational flow water entering the rotational flow body from the tangential water inlet enters the pipe body from the rotational flow of the plurality of tangential small holes formed in the pipe body, rotational flow is formed in the pipe body, water columns entering from the tangential small holes in all directions form interwoven water flow to mutually impact or impact with the inner wall of the pipe body, foggy water is formed, after meeting with high-pressure gas, a water film is formed, the water film is sprayed from the lower end of the pipe body and enters the dissolved air water area 6 downwards, and aeration is carried out by the aerator to form micro bubbles. Preferably, a liquid level meter is arranged between the gas-dissolved water area and the cyclone subinterval to detect the liquid level condition of the gas-dissolved water area.

The cyclone subarea 8 or the filler area 7 is arranged above the gas-water dissolving area to form a secondary gas dissolving structure, so that the specific surface area of gas and water is increased, water with the increased specific surface area of gas and water is mixed with high-pressure gas to obtain gas-water dissolving water, the gas-water dissolving water falls into the gas-water dissolving area 6, aeration is carried out by the aerator 601, and the gas contained in the gas-water dissolving water is more than the gas-water dissolving water obtained by primary gas dissolving, so that bubbles generated after aeration by the aerator are small, and micro bubbles can also be obtained.

Preferably, a three-stage gas dissolving structure is adopted, the specific surface area increasing area comprises a cyclone subarea 8 and a filler area 7, the upper end of the tank body is provided with the cyclone subarea 8, the lower end of the tank body is provided with a gas-water dissolving area 6, the filler area is positioned between the gas-water dissolving area and the cyclone subarea, a water inlet is positioned between an upper plugging plate and a lower plugging plate, water enters the cyclone subarea 8 from a water inlet 903 of the tank body, the gas-water specific surface area of the water is increased after the water passes through the cyclone subarea to promote the water and water to be dissolved, the water passes through the cyclone to form cyclone to meet high-pressure gas to form gas-dissolved water, the gas-dissolved water is sprayed out of the cyclone to enter the filler area 7, when the water is sprayed from the cyclone subarea 8 to meet the filler 702, gaps are formed among the fillers to further disperse the gas-dissolved water, the contact area of the water and the gas can be enhanced again, the combination of the air and the water further gas-dissolved water flows into the gas-water dissolving area 6, meanwhile, the aerator 601 continuously aerates and dissolves gas again, and the gas-water dissolving area 6, the filler area 7 and the cyclone sub-area 8 form a three-stage gas dissolving area.

The level gauge sets up between aeration pipe and packed bed, and high water level and low water level in the monitoring jar body prevent that the water level from surpassing the water level upper limit and getting into the filler district, and the water level is guaranteed to have sufficient water yield to supply the air supporting to use to the control lower limit water level. In the embodiment shown in fig. 2, first level gauge interface 905 is located above and below the packed bed 701, and second level gauge interface 906 is located below first level gauge interface 905 and above the aerator, adjacent to the aerator.

When the device works, high-pressure water enters a cyclone body of the tank body 9 from the water inlet 903 in a tangential cyclone mode, the high-pressure gas enters the tank body 9 from the air inlet 901, the tank body is filled with the high-pressure gas, the high-pressure water enters the tube body from the water inlet in a tangential cyclone mode to meet the high-pressure gas to form fine water columns, the water columns enter the tube body through the small-hole cyclone tangents spirally distributed on the tube body to form cyclone flow downwards, meanwhile, the water columns entering through small holes in different directions are mutually interwoven to form jet flow to mutually impact or impact with the tube wall to form water mist to meet the high-pressure gas to form an air film, the specific surface area of water and gas is increased, the high-pressure gas is dissolved in the water, the dissolved gas amount of the water is increased, and primary dissolved gas is formed; the gas-dissolving water of the first-stage gas-dissolving is jetted from the tube body of the cyclone to be mixed with the gas above the filler area, the gas flows into the filler area, gaps are formed among the fillers, the specific surface area of the gas-dissolving water is increased, the gas is further dissolved to form second-stage gas-dissolving, the gas-dissolving water after the second-stage gas-dissolving flows downwards to the gas-dissolving water area, high-pressure air enters the gas-dissolving water from the aerator to aerate the gas-dissolving water, and the specific surface area of the water after passing through the cyclone sub-area and the filler area is increased for the second time, so that the specific surface area of the water and the gas during aeration is large, the aeration can obtain micro bubbles which are smaller than the bubbles generated by aeration in the water without increasing the specific surface area, the gas quantity dissolved in the water is more, and the third-stage gas-dissolving is formed. The upper limit and the lower limit of the water level are monitored and controlled by the liquid level meter, when the dissolved air amount in water is increased, the air consumption is increased, high-pressure air is filled into the tank body to press down the water level when the water level reaches the upper limit, and the air filling into the tank body is stopped when the water level is lower than the lower limit of the water level.

By adopting the gas dissolving device with the structure of the invention, gas is dissolved in the three-stage gas dissolving area, water is cut into a gas-water mixed film in the cyclone area by cyclone, the specific surface area is increased for the first time, the gas dissolving water in the filler area is increased by the specific surface area of a plurality of fillers, the contact area of the water and the gas is increased, the water is directly contacted with the gas, the gas is further dissolved in the water, the water has surface tension and viscosity, the water is further scattered by high-pressure gas in the filler area, the viscosity of the scattered water is reduced, the gas dissolving amount is increased, the specific surface area of the gas and the gas is further increased, the mixing capacity of the gas and the water is increased, the water is sprayed and enters the gas-dissolving water area 6, the gas is further dissolved by the aerator 601, the utilization rate of compressed air is remarkably improved, the gas dissolving effect is increased, the power loss is reduced, the gas dissolving capacity is remarkably improved, the gas dissolving amount in one liter of water is increased to more than 13g from 7g by the three-stage gas dissolving, the gas dissolving amount is improved by more than 40 percent. The air is treated by three-stage air dissolving, so that the utilization rate of compressed air is obviously improved, the air dissolving effect is enhanced, and the power loss is reduced.

The following examples may be specifically employed to carry out the three-stage gas dissolution. The pressure of air entering the tank body is 0.4 MPa, the pressure of water is 0.3MPa, the aerator adopts a tubular aeration unit, the aeration pipe adopts a micro-bubble diaphragm pipe, the model specification of the aeration pipe is tld-65, the inner diameter of the pipe body of the cyclone is 80mm, the diameter of a small hole arranged on the pipe body of the cyclone is 2mm, the filler adopts a stainless steel ring, and the ring diameter is 20 mm. The liquid level meter is connected with an electromagnetic valve arranged at the air inlet through an electric signal.

Preferably, a water-gas mixing section 915 is arranged between the cyclone sub-area 8 and the packing area 7, so that the gas-dissolved water formed in the cyclone sub-area is sprayed downwards to reach the packing area with a certain distance, and the gas-dissolved water and the gas are fully mixed and are dissolved again.

Preferably, a vent 902 is provided in the top of the tank and an inspection port 914 is provided in the tank seat.

The dissolved air system can be combined with an air floatation device and a filtering system to obtain a sewage treatment system suitable for removing oil stains.

The air floatation device in the sewage treatment system is arranged above the filtering tank, the dissolved air system is communicated with the air floatation device through an air floatation releaser, the air floatation device is positioned above the filtering tank, and the air floatation releaser is positioned beside the filtering tank. The air floating device comprises an air floating tank 200, the shape and size of the air floating tank 200 are preferably similar to those of the filtering tank 110, the filtering tank 110 can be set to be any shape, such as circular, rectangular and the like, and correspondingly, the shape of the air floating tank is also circular, rectangular and the like. The bottom wall or the side wall of the air flotation tank 200 is provided with a purified water outlet (not shown in the figure), the air flotation tank is composed of a plurality of sub-tank bodies with basically consistent shapes, sizes and structures, the wall of each sub-tank body 115 is respectively provided with a water inlet 114, the water inlet 114 of each sub-tank body 115 is respectively communicated with the purified water outlet of the air flotation tank 200 through a water pipe 300, and each water pipe 300 is respectively provided with a valve 301 for controlling the on-off and the flow of the corresponding water pipe 300. Like this strain check 120 in every minute cell body 115 can all filter respectively and the backwash, when needs carry out the backwash, can only strain check 120 to one at every turn and carry out the backwash, remaining strain check 120 and can also normally filter, and the air supporting device can continuously work, makes backwash, filtration, air supporting go on simultaneously, and this helps improving sewage treatment's efficiency. As shown in fig. 3, each filter cell preferably employs a V-shaped filter structure. Each filter cell 120 includes two distribution weirs 121 for water inflow, a drain channel 122 for discharging backwash wastewater, a gas-water distribution channel 123 for water discharge and backwash steam and water inflow, and two filter material beds 124. The water distribution weir 121, the water discharge channel 122 and the air water distribution channel 123 are all in the shape of a long-strip groove and are all arranged along the radial direction of the cell body 115. The two water distribution weirs 121 are respectively arranged on the radial side walls of the corresponding sides of the corresponding water distribution tank body 115, the cross sections of the water distribution weirs 121 are V-shaped, a plurality of water distribution small holes 128 are arranged on the side walls opposite to the two water distribution weirs 121, namely the side walls facing the inside of the corresponding water distribution tank body 115, and the water distribution small holes 128 are uniformly arranged in a row along the length direction of the water distribution weirs 121. The gas-water distribution channel 123 is located between the two water distribution weirs 121 and is fixedly arranged at the bottom of the filtering tank 110, and the drainage channel 122 is fixedly arranged above the gas-water distribution channel 123. The top of each of the distribution weir 121 and the drain channel 122 is open and the top surface of the distribution weir 121 is higher than the top surface of the drain channel 122. The air-water distribution channel 123 and the drainage channel 122 divide the filter grid 120 into two filter areas separated from each other, and filter material beds 124 are respectively arranged in the two filter areas and divide the corresponding filter areas into an upper part and a lower part, wherein the area above the filter material beds is a raw water area 129, and the area below the filter material beds is a water purification area 125. The filter material bed 124 comprises a filter plate and filter materials, the filter plate is horizontally and fixedly arranged on the wall of the filter tank 110, a plurality of filter caps are uniformly arranged on the filter plate, the filter materials are sand materials and are uniformly paved on the filter plate, the filter caps allow water to pass through and do not allow the filter materials to pass through, and the upper surface of the filter materials is lower than the top surface of the drainage channel 122 and the water distribution pores 128 of the water distribution weir 121. The outer circumferences of the water distribution weir 121, the water discharge channel 122 and the air distribution channel 123 are fixedly and hermetically connected with the outer circumference of the sub-tank body, and as shown in fig. 1 and 4, the outer circumferential wall of the sub-tank body 115 is provided with an air inlet 111, a clean water port 112 and a sewage outlet 113. The drain 113 is communicated with the drainage channel 122, the drainage channel 122 and the gas distribution channel 123 are separated by the inclined plate 130, one end of the inclined plate 130 close to the wall of the filter tank is lower, and the bottom end of the drain is flush with the lower end of the inclined plate, so that the sewage in the drainage channel 122 can be drained conveniently. The air-water distribution channel 123 is integrally closed, the air inlet 111 and the water purification port 112 are respectively arranged corresponding to the positions of the air-water distribution channel, the air-water distribution channel 123 is communicated with the outside of the filter tank only through the air inlet 111 and the water purification port 112, the side wall of the air-water distribution channel 123 is provided with a plurality of air distribution holes 126 and water distribution holes 127 which are communicated with the water purification area 125 and the inside of the air-water distribution channel 123, the air distribution holes 126 are arranged in a plurality and are uniformly distributed in a row along the length direction of the air-water distribution channel 123, the air distribution holes 126 are arranged at the top of the side wall of the air-water distribution channel 123, the water distribution holes 127 are also arranged in a plurality and are uniformly distributed in a row along the length direction of the air-water distribution channel 123, and the water distribution holes 127 are arranged at the bottom of the side wall of the air-water distribution channel 123. The filter lattice forms a structure similar to a V-shaped filter, and the V-shaped filter has the advantages of good filtering effect, high efficiency, large treatment flow and convenience in backwashing. In use, water treated by the floatation tank 200 flows into the water distribution weir 121 through the water pipe 300, water in the water distribution weir 121 flows out from the upper end opening and the water distribution small holes 128 and then enters the raw water region 129, water in the raw water region 129 enters the water purification region 125 after being filtered by the filter material bed 124, and water in the water purification region 125 enters the air-water distribution channel 123 through the water distribution holes 127 and then flows out of the filter tank 110 through the water purification port 112. When backwashing is carried out, the valve 301 corresponding to the filter lattice 120 to be backwashed is closed, the water discharging speed in the filter lattice 120 is made to be larger than the water inlet speed, after the water in the filter lattice 120 is basically emptied, compressed air is introduced from the air inlet 111 to the air-water distribution channel 123 corresponding to the filter lattice 120, the compressed air enters the water purification area 125 through the air distribution holes 126, backwash water with pressure is introduced from the water purification port 112 to the air-water distribution channel 123, the backwash water enters the water purification area 125 through the water distribution holes 127, after the water purification area 125 is filled with the air-water mixture, the air-water mixture continuously washes the filter bed 124 upwards, the air-water combination washes dirt out, the water entering the water distribution weir is discharged from the water distribution holes 128 under the action of gravity to wash the upper surface of the filter bed 124, and meanwhile, the rest filter lattices 120 are normally filtered. During backwashing, a small amount of sewage enters the water distribution weir 121 to play a role of washing the filter material bed 124, and all the sewage can be prevented from being concentrated in the rest filter lattices 120 at the same time, so that the large treatment pressure on other filter lattices 120 during backwashing can be reduced, and the impact on the filter device caused by the large increase of the sewage amount in a short time can be reduced.

Claims

1. The gas dissolving system comprises a sealed tank body, a water outlet (911) is arranged on the tank body, and the gas dissolving system is characterized in that at least two gas dissolving areas are arranged in the tank body, and comprise a gas dissolving water area (6) and a specific surface area increasing area, the specific surface area increasing area is arranged above the gas dissolving water area (6), an aerator (601) is arranged in the gas dissolving water area, the gas outlet end of the aerator is arranged in the tank body and is positioned in the gas dissolving water, the gas inlet end of the aerator is arranged outside the tank body and is communicated with the gas outlet of a high-pressure gas supply device, the specific surface area increasing device is arranged in the specific surface area increasing area, a water inlet (903) is arranged at the position, corresponding to the specific surface area increasing device, on the tank body, water is increased in specific surface area by the specific surface area increasing device and is dissolved with high-pressure gas and then falls into the gas dissolving water area (6), and the water outlet is connected with the gas dissolving water area; a low water level monitor and a high water level monitor are arranged above the gas-dissolved water area, the low water level monitor and the high water level monitor are respectively in electric signal connection with an electromagnetic valve arranged at an air inlet, the electromagnetic valve is opened to charge the tank body when the water level is higher than the upper limit of the water level, the electromagnetic valve is closed when the water level is lower than the lower limit of the water level, the specific surface area increasing area comprises a cyclone subarea and a filler area, the cyclone subarea is positioned above the filler area, a specific surface area increasing device arranged in the cyclone subarea comprises an upper plugging plate, a lower plugging plate and a plurality of cyclones, the cyclones comprise a pipe body, a plurality of tangential small holes are arranged on the pipe body, the tangential small holes are spiral along the axial direction of the pipe body, the upper plugging plate and the lower plugging plate are respectively and fixedly connected with the inner wall of the tank body, and a containing cavity for containing the cyclones is formed by the upper plugging plate, the lower plugging plate and the corresponding tank body, the two ends of the pipe body are respectively and correspondingly connected with the upper plugging plate and the lower plugging plate, and correspond to the positions of the through holes arranged on the upper plugging plate and the lower plugging plate, the pipe body is communicated with the inner cavity of the tank body through the through holes, and the water inlet is positioned between the upper plugging plate and the lower plugging plate; the specific surface area increasing device arranged in the packing area comprises a packing bed, the packing bed is fixedly connected with the inner wall of the tank body, the packing is arranged on the packing bed, and the packing bed is positioned above the dissolved air-water area.

2. The gas dissolving system according to claim 1, wherein a space for mixing water and gas is provided between the cyclone sub-zone and the filler zone.

3. A dissolved air system according to any one of claim 1, wherein said water inlet is a tangential water inlet.

4. A sewage treatment system comprises an air floatation device, a filtering system and the air dissolving system according to any one of claims 1 to 3, and is characterized in that an air floatation releaser is arranged between a water outlet of the air dissolving system and a water inlet of the air floatation device, the air dissolving water generated by the air dissolving system is released into an air floatation tank through the air floatation releaser, a filtering tank of the filtering system is arranged below the air floatation tank and consists of a plurality of filtering grids, the water inlet of each filtering grid is communicated with the water purifying and discharging end of the air floatation tank through a water conveying pipe (300), and each water conveying pipe (300) is provided with a valve (301).