Landfill leachate concentrated solution treatment device

Abstract

The utility model relates to a landfill leachate concentrated solution treatment device which comprises a spray drying system and a gas-solid separation system, the spray drying system is used for atomizing landfill leachate concentrated solution and mixing the atomized landfill leachate concentrated solution with high-temperature flue gas to form a gas-solid mixture formed by mixing solid powder and high-temperature gas; the gas-solid separation system comprises a circulating dry-method reactor and a dust removal device, a first inlet of the circulating dry-method reactor is communicated with an outlet of the spray drying system, and an outlet of the circulating dry-method reactor is communicated with an inlet of the dust removal device; and a solid outlet of the dust removal device is respectively communicated with a second inlet of the circulating dry-method reactor and the ash bin through a conveying device. According to the landfill leachate concentrated solution treatment device, by arranging the circulating dry-method reactor, the solid powder can be subjected to circulating drying treatment, so that the moisture content in the solid powder formed after the landfill leachate concentrated solution is treated can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of garbage treatment, in particular to a garbage leachate concentrate treatment device. Background Art

[0002] Membrane treatment process, as a deep treatment method for landfill leachate, will produce concentrated liquid. Landfill leachate concentrated liquid is a by-product of landfill leachate treatment by membrane treatment process. Compared with landfill leachate, its concentration of organic pollutants, inorganic salts and metal ions is higher, and its biodegradability is poorer. If it is not handled properly, it will cause more serious secondary pollution.

[0003] At present, typical concentrated liquid treatment methods mainly include recharge process, advanced oxidation technology and evaporation process. However, long-term operation of recharge process will lead to accumulation of inorganic salts in leachate, increased conductivity, system paralysis, and great impact on subsequent membrane process; advanced oxidation technology uses a large amount of reagents, and there are also problems such as long treatment time and high operating costs; and existing evaporation technologies such as mechanical vapor recompression evaporation (Mechanical Vapor Recompression, MVR) and mechanical vapor compression (Mechanical Vapor Compression, MVC) have low energy consumption and simple process, but there are problems such as scaling and cleaning, and residual liquid is generated in the later stage; compared with traditional evaporation process, submerged combustion evaporation (Submerged Combustion Evaporation, SCE) technology does not have scaling problems and has high thermal efficiency, but the system has poor treatment effect on ammonia nitrogen, and will produce a large amount of evaporation residual liquid, which cannot be completely dried into solid powder, and there is a problem of safe disposal of secondary concentrated liquid.

[0004] Therefore, how to reduce the residual liquid in the product after the concentrated liquid treatment has become an important technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The utility model aims to provide a device for treating concentrated liquid of landfill leachate, so as to reduce liquid residue in the product after concentrated liquid treatment.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A garbage leachate concentrate processing device, comprising:

[0008] A spray drying system, wherein the spray drying system is used to atomize the landfill leachate concentrate and mix it with high-temperature flue gas to form a gas-solid mixture of solid powder and high-temperature gas;

[0009] A gas-solid separation system, the gas-solid separation system includes a circulating dry reactor and a dust removal device. The first inlet of the circulating dry reactor is communicated with the outlet of the spray drying system. The outlet of the circulating dry reactor is communicated with the inlet of the dust removal device. The solid outlet of the dust removal device is communicated with the second inlet of the circulating dry reactor and the ash bunker respectively through a conveying device.

[0010] In an embodiment of the present application, the spray drying system includes a spray drying tower and a high-temperature gas supply device. A rotary atomizer is provided at the top of the spray drying tower. The rotary atomizer is used to atomize and spray the leachate concentrate into the spray drying tower. The outlet of the high-temperature gas supply device is communicated with the inlet of the spray drying tower.

[0011] In an embodiment of the present application, it further includes a leachate concentrate supply device. The leachate concentrate supply device includes a leachate concentrate storage tank and a delivery pump. The delivery pump is connected between the leachate concentrate storage tank and the inlet of the rotary atomizer.

[0012] In an embodiment of the present application, it further includes a tail gas treatment system. The tail gas treatment system includes a heat exchanger and a first fan connected in series. The first heat exchange channel of the heat exchanger is communicated with the gas outlet of the dust removal device. The second heat exchange channel of the heat exchanger is communicated with the leachate concentrate storage tank. The first fan is used to send ambient air into the leachate concentrate storage tank through the second heat exchange channel of the heat exchanger.

[0013] In an embodiment of the present application, the tail gas treatment system further includes a scrubbing tower, a chimney and a second fan connected in series. The scrubbing tower is communicated with the first heat exchange channel of the heat exchanger. The chimney is arranged downstream of the scrubbing tower along the tail gas flow direction. The second fan is used to drive the tail gas to flow from the first heat exchange channel of the heat exchanger to the scrubbing tower.

[0014] In an embodiment of the present application, the high-temperature gas supply device includes a gas supply device, a gas hot blast stove and a third fan connected in series. The outlet of the gas hot blast stove is communicated with the inlet of the spray drying tower. The gas supply device is communicated with the inlet of the gas hot blast stove. The third fan is used to send gas from the gas supply device to the gas hot blast stove.

[0015] In an embodiment of the present application, the conveying device is a bidirectional screw conveyor.

[0016] In an embodiment of the present application, a sampling port is provided at the solid outlet of the bidirectional screw conveyor and / or the dust removal device.

[0017] In an embodiment of the present application, an on-line analysis system is further included. The sampling mechanism of the on-line analysis system is connected to the sampling port. The on-line analysis system is communicatively connected to the double-screw conveyor, and the on-line analysis system is configured to control the conveying direction of the double-screw conveyor according to the sample analysis result.

[0018] In an embodiment of the present application, the dust removal device is a bag filter.

[0019] As can be seen from the above technical solutions, the present utility model discloses a garbage leachate concentrate treatment device, including a spray drying system and a gas-solid separation system. Among them, the spray drying system is configured to atomize the garbage leachate concentrate and mix it with high-temperature flue gas to form a gas-solid mixture of solid powder and high-temperature gas; the gas-solid separation system includes a circulating dry reactor and a dust removal device. The first inlet of the circulating dry reactor is communicated with the outlet of the spray drying system, the outlet of the circulating dry reactor is communicated with the inlet of the dust removal device, and the solid outlet of the dust removal device is respectively communicated with the second inlet of the circulating dry reactor and the ash bin through a conveying device.

[0020] During application, the spray drying system first atomizes the garbage leachate concentrate to form tiny droplets, and then mixes the tiny droplets with high-temperature gas, thereby evaporating the water in the tiny droplets to achieve the first drying treatment of the garbage leachate concentrate. The gas-solid mixture of solid powder and high-temperature gas formed after the first drying treatment by the spray drying system first enters the circulating dry reactor for the second drying treatment, and then passes through the dust removal device for gas-solid separation. The conveying device can collect the solid powder separated by the dust removal device and send the solid powder back to the circulating dry reactor through the second inlet of the circulating dry reactor for the third drying treatment. This cycle continues until the solid powder is completely dry and the salt removal moisture content drops below the preset percentage. At this time, the conveying device sends the solid powder into the ash bin for storage.

[0021] It can be seen that for the above garbage leachate concentrate treatment device, by setting the circulating dry reactor, the solid powder can be subjected to cyclic drying treatment, thereby effectively reducing the moisture content in the solid powder formed after the treatment of the garbage leachate concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1This is a schematic structural diagram of the garbage leachate concentrate treatment device provided by the embodiment of the present utility model.

[0024] In the figure:

[0025] 1 is a circulating dry reactor; 2 is a dust removal device; 3 is a conveying device; 4 is a spray drying tower; 5 is a slag bin; 6 is a leachate concentrate storage tank; 7 is a conveying pump; 8 is a heat exchanger; 9 is a first fan; 10 is a scrubbing tower; 11 is a chimney; 12 is a second fan; 13 is a gas supply device; 14 is a third fan; 15 is a gas-fired hot blast stove. Specific embodiments

[0026] The core of the present utility model is to provide a garbage leachate concentrate treatment device, and the structural design of the garbage leachate concentrate treatment device enables it to reduce the liquid residue in the product after the concentrate treatment.

[0027] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0028] Please refer to Figure 1 , Figure 1 This is a schematic structural diagram of the garbage leachate concentrate treatment device provided by the embodiment of the present utility model.

[0029] The embodiment of the present utility model discloses a garbage leachate concentrate treatment device, and the garbage leachate concentrate treatment device includes a spray drying system and a gas-solid separation system.

[0030] Among them, the spray drying system is used to atomize the garbage leachate concentrate and mix it with high-temperature flue gas to form a gas-solid mixture of solid powder and high-temperature gas. The high-temperature gas can be obtained by fuel combustion or can be high-temperature waste gas generated in industrial production.

[0031] The gas-solid separation system includes a circulating dry reactor 1 and a dust removal device 2. The first inlet of the circulating dry reactor 1 is communicated with the outlet of the spray drying system, the outlet of the circulating dry reactor 1 is communicated with the inlet of the dust removal device 2, and the solid outlet of the dust removal device 2 is respectively communicated with the second inlet of the circulating dry reactor 1 and the slag bin 5 through the conveying device 3. The conveying device 3 selectively sends the solid powder to one of the two places, namely the circulating dry reactor 1 and the slag bin 5, according to the instruction.

[0032] During application, the spray drying system first atomizes the landfill leachate concentrate to form tiny droplets, and then mixes the tiny droplets with high-temperature gas, thereby evaporating the water in the tiny droplets to achieve the first drying treatment of the landfill leachate concentrate. The gas-solid mixture formed by mixing the solid powder and the high-temperature gas after the first drying treatment by the spray drying system first enters the circulating dry process reactor 1 for the second drying treatment, and then passes through the dust removal device 2 for gas-solid separation. The conveying device 3 can collect the solid powder separated by the dust removal device 2 and send the solid powder back to the circulating dry process reactor 1 through the second inlet of the circulating dry process reactor 1 for the third drying treatment. This cycle continues until the solid powder is completely dried and the desalted moisture content drops below the preset percentage. For example, in this case, the desalted moisture content of the solid powder can be reduced to below 1%. At this time, the conveying device 3 sends the solid powder into the ash bunker 5 for storage.

[0033] Compared with the prior art, the landfill leachate concentrate treatment device provided by the embodiment of the present invention can perform cyclic drying treatment on the solid powder by setting the circulating dry process reactor 1, thereby effectively reducing the moisture content in the solid powder formed after the treatment of the landfill leachate concentrate.

[0034] Specifically, as Figure 1 shown, in an embodiment of the present application, the spray drying system includes a spray drying tower 4 and a high-temperature gas supply device. A rotary atomizer is provided at the top of the spray drying tower 4. The rotary atomizer rotates at a high speed during operation to atomize the landfill leachate concentrate and spray it into the spray drying tower 4. The outlet of the high-temperature gas supply device is communicated with the inlet of the spray drying tower 4. The high-temperature gas conveyed by the high-temperature gas supply device mixes with the tiny droplets of the landfill leachate concentrate in the spray drying tower 4 and evaporates the water in the droplets by virtue of its own high temperature.

[0035] It should be noted that the inlet of the spray drying tower 4 can be provided at the top or bottom of the spray drying tower 4. As Figure 1 shown in the embodiment, the inlet of the spray drying tower 4 is provided at the top of the spray drying tower 4. The high-temperature gas and the tiny droplets formed by atomizing the landfill leachate concentrate both move from top to bottom in the spray drying tower 4. Correspondingly, the outlet of the spray drying tower 4 is provided at the bottom or a position close to the bottom of the spray drying tower 4.

[0036] Of course, in other embodiments, the inlet of the spray drying tower 4 can also be arranged at the bottom of the spray drying tower 4 or a position close to the bottom, so that the high-temperature gas moves upward in the spray drying tower 4. At the same time, the tiny droplets formed by atomizing the landfill leachate concentrate still move downward in the spray drying tower 4. In this solution, the outlet of the spray drying tower 4 should be arranged at the top of the spray drying tower 4 or a position close to the top. In this way, the high-temperature gas can mix with the tiny droplets formed by atomizing the landfill leachate concentrate from bottom to top, which can increase the residence time of the tiny droplets formed by atomizing the landfill leachate concentrate in the spray drying tower 4, thereby improving the drying effect.

[0037] To improve the mixing effect between the high-temperature gas and the tiny droplets, in the embodiment of the present application, the high-temperature gas moves spirally in the spray drying tower 4. To achieve this effect, a plurality of nozzles communicating with the high-temperature gas supply device can be arranged in the spray drying tower 4, and each nozzle is arranged at intervals along the circumferential direction and inclined downward to realize the spiral movement of the high-temperature gas. Or a fan blade structure can be arranged at the top of the spray drying tower 4. The fan blade structure includes a plurality of blades evenly distributed in the circumferential direction. Each blade extends along the radial direction of the spray drying tower 4, and the blade gradually twists from one end to the other end. In this way, when the high-temperature gas passes through the fan blade structure, it will change direction under the action of the blade and form a spiral movement. In Figure 1 the shown embodiment, the atomized tiny droplets form a downstream flow with the high-temperature gas moving spirally downward, and are wrapped and moved downward by the huge gas flow. The moisture in the droplets is evaporated and can be dried into solid powder in a very short time, forming a hollow spherical structure. And because the gas rotates rapidly in a spiral shape, the atomized droplets will not be sprayed onto the tower wall of the spray drying tower 4, keeping the tower wall of the spray drying tower 4 dry and not causing scaling.

[0038] Please refer to Figure 1 , in the embodiment of the present application, the landfill leachate concentrate treatment device further includes a leachate concentrate supply device. The leachate concentrate supply device includes a leachate concentrate storage tank 6 and a delivery pump 7. The leachate concentrate storage tank 6 is used to store the landfill leachate concentrate. The delivery pump 7 is connected between the leachate concentrate storage tank 6 and the inlet of the rotary atomizer, and the delivery pump 7 supplies the landfill leachate concentrate to the rotary atomizer according to a set flow rate.

[0039] It can be foreseen that since the high-temperature gas still maintains a relatively high temperature after evaporating the moisture in the landfill leachate concentrate, in one embodiment of the present application, in order to recover this part of the heat and improve the heat utilization rate of the system, as Figure 1As shown in the figure, the landfill leachate concentrate treatment device further includes a tail gas treatment system. The tail gas treatment system includes a heat exchanger 8 and a first fan 9 connected in series. The first heat exchange channel of the heat exchanger 8 is communicated with the gas outlet of the dust removal device 2, and the second heat exchange channel of the heat exchanger 8 is communicated with the leachate concentrate storage tank 6. The first fan 9 is used to send ambient air into the leachate concentrate storage tank 6 through the second heat exchange channel of the heat exchanger 8, that is, to preheat the ambient air about to be sent into the leachate concentrate storage tank 6 by using the high-temperature gas discharged from the dust removal device 2, so as to recover the heat in the high-temperature gas for preheating the landfill leachate concentrate in the leachate concentrate storage tank 6 and ensure the heat utilization rate of the system. The first fan 9 can be an induced draft fan or a blower. When the first fan 9 is an induced draft fan, the first fan 9 is arranged downstream of the heat exchanger 8 along the flow direction of the ambient air. If the first fan 9 is a blower, then the first fan 9 is arranged upstream of the heat exchanger 8 along the flow direction of the ambient air.

[0040] In the embodiment of the present application, the heat exchanger 8 includes, but is not limited to, a plate heat exchanger 8, as long as it can exchange heat between the high-temperature gas and the ambient air.

[0041] The high-temperature gas evaporates the water in the landfill leachate concentrate and will inevitably carry some pollutants in the landfill leachate concentrate. If it is directly discharged without treatment, it will cause environmental pollution. Therefore, in the embodiment of the present application, the tail gas treatment system further includes a scrubbing tower 10, a chimney 11 and a second fan 12 connected in series. The scrubbing tower 10 is communicated with the first heat exchange channel of the heat exchanger 8. The chimney 11 is arranged downstream of the scrubbing tower 10 along the flow direction of the tail gas. The second fan 12 is used to drive the tail gas to flow from the first heat exchange channel of the heat exchanger 8 to the scrubbing tower 10. Of course, the above scrubbing tower 10 is only a feasible solution provided in one embodiment of the present application, and it is not actually limited thereto. In other embodiments, according to needs, the scrubbing tower 10 can also be replaced with other tail gas treatment equipment, or other tail gas treatment equipment can be added on the basis of the scrubbing tower 10.

[0042] Similar to the first fan 9, in the embodiment of the present application, the second fan 12 can be an induced draft fan or a blower, and the second fan 12 can be connected in series between the scrubbing tower 10 and the chimney 11 and / or in series between the scrubbing tower 10 and the heat exchanger 8.

[0043] Please refer to Figure 1, in an embodiment of the present application, the high-temperature gas supply device includes a gas supply device 13, a gas hot blast stove 15, and a third fan 14 connected in series. The outlet of the gas hot blast stove 15 is communicated with the inlet of the spray drying tower 4, the gas supply device 13 is communicated with the inlet of the gas hot blast stove 15, and the third fan 14 is used to send the gas from the gas supply device 13 to the gas hot blast stove 15. The gas supplied by the gas supply device 13 includes but is not limited to desulfurized biogas and natural gas. The third fan 14 can be an induced draft fan or a blower. To avoid the third fan 14 from contacting the high-temperature gas and extend the service life of the third fan 14, the third fan 14 is connected in series between the gas supply device 13 and the gas hot blast stove 15.

[0044] The above high-temperature gas supply device can generate high-temperature gas at about 400 °C.

[0045] As Figure 1 shown, in an embodiment of the present application, the conveying device 3 is a two-way screw conveyor, and the two end outlets of the two-way screw conveyor are respectively communicated with the second inlet of the circulating dry process reactor 1 and the ash bin 5.

[0046] To ensure that the desalted moisture content of the solid powder drops below the preset percentage, in the embodiment of the present application, a sampling port is provided at the solid outlet of the two-way screw conveyor and / or the dust removal device 2. Users can take samples from the solid outlet of the two-way screw conveyor and / or the dust removal device 2 through the sampling port for analysis. When the desalted moisture content of the solid powder drops below the preset percentage, control the two-way screw conveyor to convey the solid powder to the ash bin 5.

[0047] To further optimize the above technical solution, in an embodiment of the present application, the landfill leachate concentrate treatment device further includes an on-line analysis system. The sampling mechanism of the on-line analysis system is connected to the sampling port, and the on-line analysis system is communicatively connected to the two-way screw conveyor. The on-line analysis system is used to control the conveying direction of the two-way screw conveyor according to the sample analysis result, so as to realize the automatic control of the landfill leachate concentrate treatment device.

[0048] As Figure 1 shown, in an embodiment of the present application, the dust removal device 2 includes one or more bag filters. When the dust removal device 2 includes multiple bag filters, each bag filter is connected in parallel or in series. Of course, the dust removal device 2 is not limited to bag filters. The dust removal device 2 can also adopt other types of dust collectors, or simultaneously adopt multiple dust collectors with different structures, such as cyclone dust collectors, which are not limited here.

[0049] Since high-temperature gas is used to evaporate and dry the droplets of the landfill leachate concentrate in this case, and the temperature of the high-temperature gas can reach about 400°C, the temperature inside the bag filter can be increased to about 150°C, which can avoid the problem of bag sticking and reduce the maintenance frequency and cost of the bag filter.

[0050] To further optimize the above technical solution, in order to control the delivery volume of the delivery pump 7, a moisture measurement device is provided at least at one of the following three locations: the outlet of the spray drying tower 4, the outlet of the circulating dry reactor 1, and the gas outlet of the dust removal device 2. The moisture measurement device is used to reduce the delivery volume of the delivery pump 7 when the moisture in the measured gas or gas-solid mixture exceeds a first preset value until the moisture in the gas or gas-solid mixture is less than or equal to the first preset value.

[0051] It should be noted that the various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference can be made to each other.

[0052] Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A landfill leachate concentrate treatment device, characterized in that: include: A spray drying system, wherein the spray drying system is used to atomize the landfill leachate concentrate and mix it with high-temperature flue gas to form a gas-solid mixture of solid powder and high-temperature gas; A gas-solid separation system, the gas-solid separation system includes a circulating dry reactor and a dust removal device, the first inlet of the circulating dry reactor is connected to the outlet of the spray drying system, the outlet of the circulating dry reactor is connected to the inlet of the dust removal device, and the solid outlet of the dust removal device is connected to the second inlet of the circulating dry reactor and the ash bin through a conveying device.

2. The garbage leachate concentrate treatment device according to claim 1, characterized in that: The spray drying system includes a spray drying tower and a high-temperature gas supply device. A rotary atomizer is arranged on the top of the spray drying tower. The rotary atomizer is used to atomize and spray the landfill leachate concentrate into the spray drying tower. The outlet of the high-temperature gas supply device is connected to the inlet of the spray drying tower.

3. The garbage leachate concentrate treatment device according to claim 2, characterized in that: It also includes a leachate concentrate supply device, which includes a leachate concentrate storage tank and a delivery pump. The delivery pump is connected between the leachate concentrate storage tank and the inlet of the rotary atomizer.

4. The garbage leachate concentrate treatment device according to claim 3, characterized in that: It also includes an exhaust gas treatment system, which includes a heat exchanger and a first fan connected in series, the first heat exchange channel of the heat exchanger is connected to the gas outlet of the dust removal device, the second heat exchange channel of the heat exchanger is connected to the leachate concentrate storage tank, and the first fan is used to send ambient air into the leachate concentrate storage tank through the second heat exchange channel of the heat exchanger.

5. The garbage leachate concentrate treatment device according to claim 4, characterized in that: The exhaust gas treatment system also includes a washing tower, a chimney and a second fan connected in series. The washing tower is connected to the first heat exchange channel of the heat exchanger. The chimney is arranged downstream of the washing tower along the exhaust gas flow direction. The second fan is used to drive the exhaust gas from the first heat exchange channel of the heat exchanger to the washing tower.

6. The device for treating concentrated landfill leachate according to any one of claims 2 to 5, characterized in that: The high-temperature gas supply device includes a gas supply device, a gas hot blast furnace and a third fan connected in series, the outlet of the gas hot blast furnace is connected to the inlet of the spray drying tower, the gas supply device is connected to the inlet of the gas hot blast furnace, and the third fan is used to send gas from the gas supply device to the gas hot blast furnace.

7. The device for treating concentrated landfill leachate according to any one of claims 1 to 5, characterized in that: The conveying device is a bidirectional screw conveyor.

8. The device for treating concentrated landfill leachate according to claim 7, characterized in that: The solid outlet of the bidirectional screw conveyor and / or the dust removal device is provided with a sampling port.

9. The garbage leachate concentrate treatment device according to claim 8, characterized in that: It also includes an online analysis system, a sampling mechanism of the online analysis system is connected to the sampling port, the online analysis system is communicatively connected with the bidirectional screw conveyor, and the online analysis system is used to control the conveying direction of the bidirectional screw conveyor according to the sample analysis results.

10. The garbage leachate concentrate treatment device according to any one of claims 1 to 5, characterized in that: The dust removal device is a bag dust collector.

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