CN113375170A - A atomizing drying process system that is used for landfill leachate membrane to strain concentrate - Google Patents

Abstract

The invention relates to an atomization drying treatment system for landfill leachate membrane filtration concentrated solution, which belongs to the technical field of landfill leachate treatment and comprises a feeding device, a pretreatment device, an atomization drying device, a dust remover and a gas purification device which are sequentially arranged along the flowing direction of the concentrated solution, wherein the pretreatment device is used for softening the concentrated solution so as to reduce the scaling of the concentrated solution and the corrosion to the system. The invention can effectively treat the membrane filtration concentrated solution of the landfill leachate and realize zero discharge of waste water; meanwhile, the discharge of COD and salt is reduced, and the environment is protected; has the advantages of good treatment effect, low operation cost and no secondary pollution, and achieves the aim of environmental protection and energy conservation.

Description

A atomizing drying process system that is used for landfill leachate membrane to strain concentrate

Technical Field

The invention belongs to the technical field of landfill leachate treatment, and relates to an atomization drying treatment system for membrane filtration concentrated solution of landfill leachate.

Background

With the continuous improvement of the environmental protection requirement, the discharge standard of the percolate is becoming stricter, and the nanofiltration reverse osmosis technology is the most reliable technology for meeting the current standard. At present, more than 90% of domestic percolate projects adopt a biochemical treatment and membrane treatment system to generate a large amount of membrane filtration concentrated solution, pollutants in the membrane filtration concentrated solution mainly comprise humic acid organic matters and salts, and the membrane filtration concentrated solution has the characteristics of high concentration, difficult degradation and larger treatment difficulty.

The safe treatment and disposal of the membrane filtration concentrated solution are the bottleneck of the development of the current percolate treatment technology, and are the key points and difficulties of environmental management. At present, membrane filtration concentrated solution is mainly treated by means of recharging, evaporation, incineration, concentrated liquid membrane separation and the like, and is mainly characterized in that:

the concentrated solution recharging technology is to re-introduce the concentrated solution into a landfill system through a recharging system and gradually degrade toxic and harmful substances in the concentrated solution through the landfill. The technology has low cost and wide application, but the technology has great limitation in use, a plurality of projects do not have landfill sites for recharging, even if the landfill sites have high water content and are extremely difficult to recharge due to the garbage heap body, the conductivity and the salt concentration of the leachate are easy to continuously rise even if the landfill sites are recharged, and the subsequent treatment difficulty is increased.

And secondly, concentrated solution evaporation technologies are mainly divided into Submerged Combustion Evaporation (SCE) and mechanical vapor recompression evaporation (MVR). The submerged combustion evaporation system can generate 10% -20% of residual liquid which is not treated, and the unit treatment cost of the concentrated solution is greatly increased as hazardous waste treatment. The mechanical vapor recompression evaporation technology is affected by scaling and foam, and continuous and stable operation is difficult to realize.

And thirdly, the concentrated solution incineration technology is mainly characterized in that the concentrated solution is sprayed back to the incinerator, so that the concentrated solution is seriously corroded to incineration system equipment and the incineration generating capacity is influenced.

The concentrated solution membrane separation technology of the concentrated solution is to filter the concentrated solution by using a concentrated solution membrane, the filtering aperture is between the ultrafiltration and the nanofiltration, ammonia nitrogen and total nitrogen in the concentrated solution are difficult to remove, and the concentrated solution membrane still generates the concentrated solution to be treated.

Therefore, it is necessary to intensively study the membrane filtration concentration technology based on the prior art, thereby systematically solving the difficulty of the treatment of the percolate membrane filtration concentrate.

Disclosure of Invention

In view of this, an object of the present application is to provide an atomization drying processing system for landfill leachate membrane filtration concentrate, so as to reduce the processing cost of the concentrate and improve the operation stability of the system.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides an atomizing drying process system for landfill leachate membrane filters concentrate, includes feedway, preprocessing device, atomizing drying device, dust remover and the gas purification device that sets up in order along the concentrate flow direction, and preprocessing device is used for softening the concentrate in order to reduce concentrate scale deposit and to the corruption of system.

Optionally, a back-flushing device is also provided for automatic cleaning of the system.

Optionally, the backwashing device comprises a backwashing acid tank connected to the outlet end of the feeding device, and the backwashing acid tank is supplied with acid through an acid supply pump.

Optionally, the system further comprises a preheating tower connected with the pretreatment device and the dust remover, so that the concentrated solution is preheated by using the fluid heat energy of the atomization drying device, and the heat energy in the system is recycled.

Optionally, the gas purification device comprises a spraying device, an acid washing device, an alkali washing device and a deodorization device which are sequentially arranged along the flowing direction of the concentrated solution, wherein the spraying device sprays the concentrated solution by adopting spray water containing citric acid so as to reduce the blockage of the spraying device.

Optionally, the atomization drying device comprises a drying tower, a hot air distributor is arranged in the middle of the top of the drying tower, an atomizer is arranged in the middle of the hot air distributor, and hot air passing through the hot air distributor is uniformly and rotationally blown downwards into the drying tower to realize the solidification of the mist point of the micro concentrated solution formed by the atomizer.

Optionally, the drying tower includes cylinder section and the awl section that is setting from top to bottom, and the bottom of awl section is equipped with residue collection device, and the lateral wall of awl section of thick bamboo end is equipped with the gas outlet with the dust remover intercommunication.

Optionally, the hot air distributor is provided with an inner guide vane and an outer guide vane to realize the adjustment of the air inlet speed and the air inlet angle.

Optionally, the hot air of the atomization drying device is derived from hot flue gas generated by burning garbage or biogas.

Optionally, the feeding device is further provided with an emergency pipeline directly connected with the atomization drying device, and the emergency pipeline is provided with a control valve to bypass the pretreatment device and directly enter the atomization drying device when the pretreatment device fails.

The invention has the beneficial effects that:

according to the invention, the hot air distributor and the atomizer are arranged in the middle of the top of the drying tower, so that the concentrated solution is far away from the inner wall of the drying chamber of the drying tower, and the concentrated solution is prevented from crystallizing on the inner wall of the drying chamber in the operation process; the design of the hot air distributor positioned at the top of the drying tower is optimized, hot air is ensured to uniformly enter the drying tower, the heat exchange efficiency is improved, and the running cost is reduced; by adjusting the wind speed and the wind direction of the hot wind distributor, the concentrated solution is further prevented from generating crystallization on the inner wall of the drying tower, and the cleaning period of the drying chamber is prolonged; the pretreatment device is arranged, so that corrosion and scaling of the concentrated solution to equipment and pipelines are avoided; by arranging the back washing device, the stable operation time of the equipment is improved.

The invention can effectively treat the membrane filtration concentrated solution of the landfill leachate and realize zero discharge of waste water; meanwhile, the discharge of COD and salt is reduced, and the environment is protected; has the advantages of good treatment effect, low operation cost and no secondary pollution, and achieves the aim of environmental protection and energy conservation.

The invention solves the problem of difficult concentrated solution treatment in the percolate treatment industry, has better economic benefit, environmental protection benefit and remarkable social benefit, is suitable for treating the concentrated solution of percolate of domestic garbage incineration power plants and domestic garbage landfill sites, can be applied to concentrated solution treatment in the field of high-salinity wastewater or other wastewater treatment, and has higher application prospect and popularization value.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an atomizing drying process system according to the present invention;

fig. 2 is a schematic structural view of the atomization drying device.

Reference numerals: the system comprises a drying tower 1, a hot air distributor 2, an atomizer 3, a dust remover 4, a preheating tower 5, a pretreatment device 6, a concentrated solution tank 7, a feed pump 8, a spray device 9, a back flushing device 10, an acid washing device 11, an alkali washing device 12 and a deodorization device 13.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Referring to fig. 1-2, an atomization drying treatment system for landfill leachate membrane filtration concentrate includes a feeding device, a pretreatment device 6, an atomization drying device, a dust remover 4, and a gas purification device, which are sequentially arranged along a flow direction of the concentrate, wherein the pretreatment device 6 is used for softening the concentrate to reduce scaling of the concentrate and corrosion to the system.

The invention is also provided with a back washing device 11 for automatically cleaning the system, thereby prolonging the service life of the system. When the system is maintained regularly, the system can be cleaned automatically and the maintenance efficiency is improved. The backwashing device 11 comprises a backwashing acid tank connected to the outlet end of the feeding device, and the backwashing acid tank is supplied with acid through an acid supply pump.

The invention also comprises a preheating tower 5 connected with the pretreatment device 6 and the dust remover 4, so as to preheat the concentrated solution by utilizing the fluid heat energy of the atomization drying device, thereby realizing the recycling of the heat energy in the system. The concentrate in the preheating column 5 can be conveyed to the atomizing drying device by means of a pump or by means of a height difference.

The feeding device is also provided with an emergency pipeline directly connected with the atomization drying device, and the emergency pipeline is provided with a control valve so as to bypass the pretreatment device 6 and directly enter the atomization drying device when the pretreatment device 6 breaks down.

The gas purification device comprises a spraying device 9, an acid washing device 12, an alkali washing device 13 and a deodorization device 13 which are sequentially arranged along the flowing direction of the concentrated solution, wherein the spraying device 9 adopts spray water containing citric acid to spray the concentrated solution so as to reduce the blockage of the spraying device 9, and the deodorization device 13 is preferably an active carbon deodorization device.

In order to reduce the operation cost, the hot air of the atomization drying device is derived from hot flue gas generated by burning garbage or methane.

The atomizing and drying device is a vertical type upper-spraying lower-parallel-flow structure and is used for drying soluble solids in concentrated solution into solid residues, the atomizing and drying device comprises a drying tower 1, a hot air distributor 2 is arranged in the middle of the top of the drying tower 1, an atomizer 3 is arranged in the middle of the hot air distributor 2, hot air passing through the hot air distributor 2 is uniformly and rotatably blown downwards into the drying tower 1, and therefore tiny concentrated solution mist spots formed by the atomizer 3 are solidified. Drying tower 1 is equipped with residue collection device including being cylinder section and the awl section that sets up from top to bottom, the bottom of awl section, and the lateral wall of awl section of thick bamboo end is equipped with the gas outlet with dust remover 4 intercommunication.

The hot air distributor 2 is provided with an inner guide vane and an outer guide vane so as to realize the adjustment of air inlet speed and air inlet angle. The hot air distributor is also connected with a cyclone separator so that hot air is uniformly and rotatably blown downward into the drying tower 1 through a hot air distributor 2 at the top of the drying tower 1.

Examples

An atomization drying treatment system for landfill leachate membrane filtration concentrated solution comprises an atomization drying device, a dust remover 4, a preheating tower 5, a pretreatment device 6, a concentrated solution tank 7, a feeding pump 8, a spray tower 9, a backwashing device 10, an acid washing device 11, an alkali washing device 12 and a deodorization device 13. The concentrated solution tank 7, the pretreatment device 6, the feed pump 8, the atomization drying device, the dust remover 4, the preheating tower 5, the spray tower 9, the backwashing device 10, the acid washing device 11, the alkaline washing device 12 and the deodorization device 13 are sequentially arranged according to the material flowing direction. The pretreatment device 6 is connected with the preheating tower 5 to preheat the concentrated solution by utilizing the fluid heat energy of the atomization drying device, so that the heat energy in the system can be recycled. Atomizing drying device includes drying tower 1, hot air distributor 2 and atomizer 3, and hot air distributor 2 is located the top middle part of drying tower, and atomizer 3 is located hot air distributor 2's inboard and coaxial setting. Drying tower 1 is equipped with residue collection device including being cylinder section and the awl section that sets up from top to bottom, the bottom of awl section, and the lateral wall of awl section of thick bamboo end is equipped with the gas outlet with dust remover 4 intercommunication. The backwashing device 10 comprises an acid liquid tank and an acid supply pump, the dust remover 4 adopts a bag-type dust remover, the atomizer 3 adopts a high-speed centrifugal atomizer, and the deodorizing device 13 adopts an active carbon deodorizing device.

The pretreatment device 6 is a concentrated solution pre-precipitation softening device, and the concentrated solution passes through the pretreatment device 6 to remove calcium in the concentrated solution, so that scaling and corrosion to equipment and pipelines are reduced, and the stable operation time of the system is improved; the treated concentrated solution enters a preheating tower 5 for preheating so as to recover the heat of the fluid at the outlet of the drying tower. The heated concentrated solution is conveyed to an atomizer inlet at the top of the drying tower through a feed pump 8, and enters the drying tower 1 after being atomized through an atomizing disc of the atomizer 3.

The atomization drying device mainly has the function of drying soluble solids in the concentrated solution into solid residues. The atomizing and drying device is of a vertical type upper spraying and lower parallel flow type and is controlled by a linkage automatic adjustment (PLC), and the model selection calculation of the atomizing and drying device has great influence on the efficiency improvement, the operation cost and the operation stability of the system. According to the characteristics and the treatment capacity of the concentrated solution and the final states of the treated smoke and residues, heat exchange calculation is carried out, the smoke gas consumption amount of the atomization drying device is determined, the evaporation intensity of the atomization drying device is determined, and then the diameter and the evaporation volume of the drying tower are determined. The hot flue gas for drying can be realized by utilizing the waste heat of the flue gas of an incineration plant, field methane and the like, so that the operation cost is further reduced.

The atomization drying process of the concentrated solution comprises the following steps: hot air enters a hot air distributor 2 at the top of the drying tower through a blower and a cyclone separator, and is uniformly and rotatably blown downwards into a drying chamber of the drying tower 1; the concentrated solution enters an atomizer 3 at the top of the drying tower through a feed pump 8, and the concentrated solution is dispersed into fog drops under the high-speed action of a centrifugal disc of the atomizer 3; the fog drops meet hot air, the surface moisture is quickly evaporated (constant speed drying stage), then the drying stage is started, and the soluble solid in the concentrated solution is dried into solid residue within several seconds; the gas-solid mixture moves downwards to the bottom of the drying tower, most of solid residues are discharged after the internal cyclone separation, and the micro powder enters a dust remover 4 and is collected by a high-efficiency cyclone separator.

According to the invention, the hot air distributor 2 and the atomizer 3 are arranged in the middle of the top of the drying tower 1, so that the concentrated solution is far away from the inner wall of the drying chamber of the drying tower 1, and the equipment structure is optimized through the coupling calculation of the drying tower 1 and the atomizer 3, thereby preventing the concentrated solution from crystallizing on the inner wall of the drying chamber in the operation process; the design of the hot air distributor 2 positioned at the top of the drying tower is optimized, hot air is ensured to uniformly enter the drying tower 1, the heat exchange efficiency is improved, and the running cost is reduced; by adjusting the wind speed and the wind direction of the hot wind distributor 2, the concentrated solution is further prevented from generating crystallization on the inner wall of the drying chamber, and the cleaning period of the drying chamber is prolonged; by arranging the pretreatment device 6, corrosion and scaling of the concentrated solution to equipment and pipelines are avoided; by arranging the backwashing device 11, the stable operation time of the equipment is improved.

The invention provides a reliable concentrated solution treatment system for treating high-salinity, high-organic-pollutant and high-metal ions, which can effectively treat the membrane filtration concentrated solution of the landfill leachate and realize zero discharge of wastewater; meanwhile, the discharge of COD and salt is reduced, and the environment is protected; has the advantages of good treatment effect, low operation cost and no secondary pollution, and achieves the aim of environmental protection and energy conservation.

The system has the advantages of simple structure, good anti-scaling and blocking effects, stable and reliable operation and controllable technical risk; the decrement rate of the concentrated solution reaches 92-95%, the detection of treated gas and solid products shows that the tail gas reaches the national emission standard, the solid slag belongs to general solid waste, the water content is lower than or equal to 5%, the harmless effect is good, and the decrement is thorough; compared with other evaporation technologies, the evaporation technology has the advantages of low investment and construction cost, small occupied area and more economic operation cost. The invention systematically solves the difficult problem of treating the percolate membrane filtration concentrated solution, and is a new technology which is environment-friendly and harmless and thorough.

The invention has stable production and operation, the production process and the emission index accord with the relevant national regulations and requirements, and the social, economic and environmental benefits are obvious.

The technology solves the problem of concentrated solution treatment in the percolate treatment industry, has good economic benefit, is environment-friendly, has obvious environmental protection benefit and social benefit, is suitable for treating concentrated solution of percolate of domestic garbage incineration power plants and domestic garbage landfill sites, can be applied to concentrated solution treatment in the field of high-salinity wastewater or other wastewater treatment, and has high application prospect and popularization value.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.

Claims (10)

1. The utility model provides an atomizing drying process system that is used for landfill leachate membrane to strain concentrate which characterized in that: the device comprises a feeding device, a pretreatment device, an atomization drying device, a dust remover and a gas purification device which are sequentially arranged along the flowing direction of the concentrated solution, wherein the pretreatment device is used for softening the concentrated solution so as to reduce the scaling of the concentrated solution and the corrosion to the system.

2. The system of claim 1, wherein the system comprises: a back washing device is also arranged for automatic cleaning of the system.

3. The system of claim 2, wherein the system comprises: the back washing device comprises a back washing acid tank connected to the outlet end of the feeding device, and the back washing acid tank supplies acid through an acid supply pump.

4. The system of claim 1, wherein the system comprises: the system also comprises a preheating tower connected with the pretreatment device and the dust remover, so that the concentrated solution is preheated by utilizing the fluid heat energy of the atomization drying device, and the heat energy in the system is recycled.

5. The system of claim 1, wherein the system comprises: the gas purification device comprises a spraying device, an acid washing device, an alkali washing device and a deodorization device which are sequentially arranged along the flowing direction of the concentrated solution, wherein the spraying device adopts spray water containing citric acid to spray the concentrated solution so as to reduce the blockage of the spraying device.

6. The system of claim 1, wherein the system comprises: the atomization drying device comprises a drying tower, a hot air distributor is arranged in the middle of the top of the drying tower, an atomizer is arranged in the middle of the hot air distributor, hot air passing through the hot air distributor is uniformly and rotationally blown into the drying tower downwards, and therefore the atomization point solidification of the micro concentrated solution formed by the atomizer is achieved.

7. The system of claim 6, wherein the system comprises: the drying tower is including being cylinder section and the awl section that sets up from top to bottom, and the bottom of awl section is equipped with residue collection device, and the lateral wall of awl section of thick bamboo end is equipped with the gas outlet with the dust remover intercommunication.

8. The system of claim 6, wherein the system comprises: the hot air distributor is provided with an inner side guide blade and an outer side guide blade so as to realize the adjustment of air inlet speed and air inlet angle.

9. The system of claim 1, wherein the system comprises: the hot air of the atomization drying device is derived from hot flue gas generated by burning garbage or methane.

10. The system of claim 1, wherein the system comprises: the feeding device is further provided with an emergency pipeline directly connected with the atomization drying device, and a control valve is arranged on the emergency pipeline to bypass the pretreatment device to directly enter the atomization drying device when the pretreatment device breaks down.

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