High-ammonia-nitrogen wastewater resourceful treatment device

Abstract

The utility model discloses a high ammonia nitrogen wastewater resourceful treatment device which comprises a mixing unit, a pressurized rectifying tower, a coupling reboiler, a normal pressure rectifying tower, a condensing unit and an absorption tower, an outlet of the mixing unit is respectively connected with a water inlet pipe of a spraying assembly at the upper end of the pressurized rectifying tower and a water inlet pipe of a spraying assembly at the upper end of the normal-pressure rectifying tower; a steam inlet is formed in the lower end of the pressurized rectifying tower; the bottom of the pressurized rectifying tower is connected with a liquid inlet in the lower end of the normal-pressure rectifying tower; an inlet of the coupling reboiler is connected with the top of the pressurized rectifying tower; the coupling reboiler is used as a heat source of the normal-pressure rectifying tower, and the upper end of the coupling reboiler is respectively connected with the upper end and the lower end of the normal-pressure rectifying tower through two pipelines; an inlet of the condensing unit is connected with the upper end of the normal-pressure rectifying tower; an outlet of the condensing unit is connected with the absorbing tower.

Description

TECHNICAL FIELD

[0001] The utility model relates to wastewater treatment technical field, concretely relates to a kind of high ammonia nitrogen wastewater resource treatment device. BACKGROUND

[0002] With the development of China's economy and urbanization, the scale and application range of photovoltaic solar cell industry are continuously expanded. In the process of solar panel production, a large amount of ammonia needs to be introduced in the processes of Low Pressure Chemical Vapor Deposition (LPCVD), front coating and back coating to improve the raw material S i The reaction efficiency of H4 and N2O is about 90%, so a large amount of NH3 not involved in the reaction is discharged in the form of coating tail gas, and the generated exhaust gas is usually treated by combustion cylinder + bag-type dust collector + silane combustion tower + water washing spray tower process, thereby generating high-concentration ammonia-nitrogen wastewater. The ammonia-nitrogen concentration of such wastewater is extremely high, about 5000-6000 mg / L. If it is directly discharged, it will not only cause serious damage to the surrounding environment, but also cause waste of ammonia-nitrogen resources.

[0003] The treatment methods of ammonia-nitrogen wastewater mainly include stripping method, breakpoint chlorination method, chemical precipitation method, ion exchange method and biological method. The stripping method is the main method for treating high-ammonia-nitrogen wastewater at present, which refers to adjusting the pH of wastewater to alkaline to make ammonia-nitrogen in wastewater exist in the form of free ammonia, and then introducing gas (usually air or steam) into the stripping tower to strip free ammonia from wastewater. This method is suitable for treating high-concentration ammonia-nitrogen wastewater and has the advantage of simple technology. However, the stripping method consumes a large amount of air or steam, and the process energy consumption is very high. In addition, many stripping devices do not have ammonia recovery system for economic consideration, and the ammonia overflow is directly discharged into the atmosphere, causing air pollution. If the overflow ammonia is absorbed by sulfuric acid, although ammonium sulfate can be prepared as fertilizer, the economic value is poorer than that of ammonia water. UTILITY MODEL CONTENT

[0004] Therefore, the utility model embodiment provides a high ammonia-nitrogen wastewater resource treatment device to solve the problems of the existing ammonia-nitrogen wastewater treatment methods in terms of economy and energy consumption.

[0005] The utility model embodiment provides a high ammonia-nitrogen wastewater resource treatment device, which comprises a mixing unit, a pressurized rectifying tower, a coupled reboiler, an atmospheric rectifying tower, a condensing unit and an absorption tower, wherein:

[0006] The mixing unit comprises an ammonia-nitrogen wastewater inlet and an alkaline solution inlet; the outlets of the mixing unit are connected with the water inlet pipes of the spraying assemblies at the upper ends of the pressurized rectifying tower and the atmospheric rectifying tower, respectively;

[0007] The lower end of the pressurized rectifying tower is provided with a steam inlet; the bottom of the pressurized rectifying tower is connected with the liquid inlet of the lower end of the atmospheric rectifying tower;

[0008] The inlet of the coupling reboiler is connected with the top of the pressurized rectifying tower; the coupling reboiler serves as a heat source of the atmospheric rectifying tower; the upper end of the coupling reboiler is connected with the upper end and the lower end of the atmospheric rectifying tower through two pipes respectively;

[0009] The inlet of the condensing unit is connected with the upper end of the atmospheric rectifying tower, and the outlet of the condensing unit is connected with the absorption tower.

[0010] Optionally, the system further comprises a filtering unit arranged at the outlet of the mixing unit.

[0011] Optionally, the system further comprises a pre-heating unit arranged at the outlet of the filtering unit.

[0012] Optionally, the mixing unit comprises a stirring paddle and a pH sensor; wherein the waste liquid in the mixing unit is stirred uniformly by the stirring paddle, and if the pH value of the waste liquid in the mixing unit obtained by the pH sensor is between 11.5 and 12.0, the valve of the alkaline solution sampling port is closed.

[0013] Optionally, the system further comprises a first reflux tank, the inlet of which is connected with the lower end of the coupling reboiler, and the bottom of the first reflux tank is connected with the water inlet pipe of the spraying assembly of the pressurized rectifying tower through a pipe and a first reflux pump.

[0014] Optionally, the system further comprises a second reflux tank, the inlet of which is connected with the lower end outlet of the condensing unit, and the bottom of the second reflux tank is connected with the water inlet pipe of the spraying assembly of the atmospheric rectifying tower through a pipe and a second reflux pump.

[0015] Optionally, the system further comprises a discharge pool connected with the first outlet at the bottom of the atmospheric rectifying tower through a pipe; the second outlet at the bottom of the atmospheric rectifying tower is connected with the mixing unit through a pipe pump; the third outlet at the bottom of the atmospheric rectifying tower is connected with the reboiler through a pipe;

[0016] If the deamination wastewater at the bottom of the atmospheric rectifying tower reaches the discharge standard, the first outlet at the bottom of the atmospheric rectifying tower is opened for discharge; if the deamination wastewater at the bottom of the atmospheric rectifying tower does not reach the discharge standard, the second outlet at the bottom of the atmospheric rectifying tower is opened to pump the deamination wastewater into the mixing unit.

[0017] The deamination wastewater at the bottom of the atmospheric rectifying tower enters the reboiler to exchange heat with the steam from the pressurized rectifying tower, and the heat-exchanged steam enters the upper end of the atmospheric rectifying tower.

[0018] Optionally, the top end of the absorption tower is provided with a standard waste gas discharge outlet, and the upper end of the absorption tower is provided with a water inlet of process water.

[0019] Optionally, the device further comprises a concentration spray assembly, a water inlet pipe of the concentration spray assembly being connected to the lower end of the absorption tower through a pipeline pump, and a spray head and a filler of the concentration spray assembly being arranged in the middle part of the absorption tower.

[0020] Optionally, the bottom of the absorption tower is provided with a discharge outlet, and the discharge outlet is connected to a concentrated ammonia water product tank.

[0021] The high-ammonia-nitrogen wastewater resource treatment device has the advantages that:

[0022] The high-ammonia-nitrogen wastewater resource treatment device has the advantages that:

[0023] The high-ammonia-nitrogen wastewater and the deamination wastewater are added into the mixing unit, the stirring paddle is rotated, the wastewater and the lye are mixed more uniformly, and the pH value is adjusted more quickly and accurately. The pre-heating unit reduces the steam consumption and accelerates the distillation efficiency. The ammonia-containing steam at the top of the pressurized distillation tower enters the coupled reboiler through a pipeline and is used as a heating source of the atmospheric distillation tower, the energy utilization rate is improved, the steam consumption is reduced, the energy-saving effect is obvious, and meanwhile, the pressurized distillation tower and the atmospheric distillation tower are provided with a spraying device and a filler layer, the countercurrent contact area and the reaction time of the high-ammonia-nitrogen wastewater and the steam are increased, and the gas stripping efficiency is improved.

[0024] The high-ammonia-nitrogen wastewater resource treatment device provided by the utility model does not adopt liquid-phase extraction but adopts a form of gas-phase extraction, a form of liquid-phase full reflux, and a form of concentrated ammonia gas absorption to realize the recycling of concentrated ammonia water, and the device has the advantages of simple structure and easy operation. BRIEF DESCRIPTION OF DRAWINGS

[0025] The features and advantages of the utility model will be more clearly understood through the following description with reference to the drawings, and the drawings are schematic and should not be understood as any limitation to the utility model, and in the drawings:

[0026] Figure 1 A structure diagram of the high-ammonia-nitrogen wastewater resource treatment device in the embodiment of the utility model is shown. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0028] As shown in Figure 1 The embodiments of the present application provide a high ammonia-nitrogen wastewater resource treatment device, which comprises a mixing unit 1, a pressurized rectifying tower 4, a coupled reboiler 5, an atmospheric rectifying tower 7, a condensing unit 8 and an absorption tower 10, wherein the mixing unit 1 comprises an ammonia-nitrogen wastewater inlet and an alkaline solution inlet. The outlet of the mixing unit 1 is connected with the water inlet pipe of the spraying assembly at the upper end of the pressurized rectifying tower 4 and the water inlet pipe of the spraying assembly at the upper end of the atmospheric rectifying tower 7 respectively. The lower end of the pressurized rectifying tower 4 is provided with a steam inlet; the bottom of the pressurized rectifying tower 4 is connected with the liquid inlet at the lower end of the atmospheric rectifying tower 7. The inlet of the coupled reboiler 5 is connected with the top of the pressurized rectifying tower 4; the coupled reboiler 5 serves as a heat source of the atmospheric rectifying tower 7, and the upper end of the coupled reboiler 5 is connected with the upper end and the lower end of the atmospheric rectifying tower 7 through two pipes respectively. The inlet of the condensing unit 8 is connected with the upper end of the atmospheric rectifying tower 7, and the outlet of the condensing unit 8 is connected with the absorption tower 10.

[0029] In specific embodiments, the mixing unit 1 comprises a stirring paddle and a pH sensor. The waste liquid in the mixing unit is stirred uniformly by the stirring paddle, and if the pH value of the waste liquid in the mixing unit obtained by the pH sensor is between 11.5 and 12.0, the valve of the alkaline solution inlet is closed, so as to control the addition amount of the alkaline solution.

[0030] As an optional embodiment, the device further comprises a filtering unit 2 and a pre-heating unit 3, which are sequentially arranged at the outlet of the mixing unit. The suspended impurities in the mixed ammonia-nitrogen wastewater are filtered out by the filtering unit 2, and then pumped into the pre-heating unit 3 through a pipeline for heating. The pre-heated wastewater is pumped into the spraying devices of the pressurized rectifying tower and the atmospheric rectifying tower through a pipeline.

[0031] As an optional embodiment, the device further comprises a first reflux tank 6, the inlet of which is connected with the lower end of the coupled reboiler 5, and the bottom of the first reflux tank 6 is connected with the water inlet pipe of the spraying assembly of the pressurized rectifying tower 4 through a pipeline and a first reflux pump.

[0032] In the present embodiment, the ammonia-containing steam is condensed and then enters the first reflux tank 6, and all the ammonia-containing steam is refluxed to the upper end of the pressurized rectifying tower through a pipeline as reflux liquid to enter the water inlet pipe of the spraying assembly, so as to realize cyclic deamination.

[0033] As an optional embodiment, it further comprises a second reflux tank 9, the inlet of which is connected with the outlet at the lower end of the condensing unit 8, and the bottom of the second reflux tank 9 is connected with the water inlet pipe of the spray assembly of the normal pressure rectifying tower 7 through a pipeline and a second reflux pump.

[0034] In this embodiment, the concentrated ammonia gas from the coupling reboiler 5 enters the normal pressure rectifying tower 7 at the upper end through a pipeline, and is distilled again with the concentrated ammonia gas at the top end of the normal pressure rectifying tower 7 to enter the condensing unit 8 at the top, and the condensed concentrated ammonia water flows into the second reflux tank 9 to enter the spray assembly of the normal pressure rectifying tower again as the reflux liquid.

[0035] As an optional embodiment, it further comprises a discharge pool connected with the first outlet at the bottom of the normal pressure rectifying tower through a pipeline, a second outlet at the bottom of the normal pressure rectifying tower connected with the mixing unit through a pipeline pump, and a third outlet at the bottom of the normal pressure rectifying tower connected with the reboiler through a pipeline. If the deamination wastewater at the bottom of the normal pressure rectifying tower reaches the discharge standard, the first outlet at the bottom of the normal pressure rectifying tower is opened for discharge; if the deamination wastewater at the bottom of the normal pressure rectifying tower does not reach the discharge standard, the second outlet at the bottom of the normal pressure rectifying tower is opened to pump the deamination wastewater into the mixing unit.

[0036] The deamination wastewater at the bottom of the normal pressure rectifying tower enters the reboiler to exchange heat with the steam from the pressurized rectifying tower, and the exchanged steam enters the upper end of the normal pressure rectifying tower.

[0037] In this embodiment, the valve at the third outlet is opened and closed according to the liquid level of the deamination wastewater at the bottom of the normal pressure rectifying tower.

[0038] As an optional embodiment, the top end of the absorption tower 10 is provided with a standard waste gas discharge outlet, and the upper end of the absorption tower 10 is provided with a water inlet for process water. The absorption tower 10 further comprises an enrichment spray assembly 11, the water inlet pipe of which is connected with the lower end of the absorption tower 10 through a pipeline pump, and the spray head and the filler of the enrichment spray assembly 11 are arranged in the middle part of the absorption tower 10. The bottom of the absorption tower 10 is provided with a discharge outlet connected with a concentrated ammonia water product tank.

[0039] The spray assemblies in the pressurized rectifying tower, the normal pressure rectifying tower and the absorption tower comprise a water inlet pipe, and a spiral spray head is connected below the water inlet pipe, so that the sprayed high ammonia nitrogen wastewater can be uniformly sprayed on the filler and contacted with the steam in countercurrent.

[0040] In this embodiment, the concentrated ammonia gas at the top of the normal pressure tower enters the absorption device through a pipeline, and the amount of process water added is controlled by calculating the content of ammonia nitrogen in the wastewater. When the concentration of ammonia water does not meet the requirements, the enrichment device is used for spraying and reabsorption, and when the requirements are met, the ammonia water is discharged to the concentrated ammonia water product tank through the ammonia water discharge outlet. It should be noted that the concentrated ammonia water here refers to industrial first-class product with a concentration of 25-28%.

[0041] In this embodiment, the concentrated ammonia gas at the top of the normal pressure tower enters the absorption device through a pipeline, and the amount of process water added is controlled by calculating the content of ammonia nitrogen in the wastewater. When the concentration of ammonia water does not meet the requirements, the enrichment device is used for spraying and reabsorption, and when the requirements are met, the ammonia water is discharged to the concentrated ammonia water product tank through the ammonia water discharge outlet. It should be noted that the concentrated ammonia water here refers to industrial first-class product with a concentration of 25-28%. Figure 1For example, the working principle of the high ammonia-nitrogen wastewater resource treatment device is described.

[0042] The high-concentration ammonia-nitrogen wastewater enters the mixing unit and is mixed with the deamination wastewater, under the stirring of the stirring paddle, the addition amount of lye is controlled through the pH sensor, so that the pH value of the mixed wastewater is between 11.5 and 12.0, the wastewater is pumped into the preheating unit through the pipeline for heating, the preheated wastewater is pumped into the spraying device of the pressurized rectifying tower and the atmospheric rectifying tower through the pipeline, the wastewater in the pressurized rectifying tower is countercurrently contacted with the steam entering the bottom of the pressurized rectifying tower, the gas deamination is carried out in the pressurized rectifying tower, and the deamination wastewater at the bottom of the pressurized rectifying tower is pumped into the bottom of the atmospheric rectifying tower through the pipeline.

[0043] The utility model provides a kind of high ammonia-nitrogen wastewater resource treatment device, suspended solids and impurities in high ammonia-nitrogen wastewater are removed by filtering unit, high ammonia-nitrogen wastewater is heated by preheating unit, steam consumption is reduced, by the organic combination of pressurized rectifying tower and atmospheric rectifying tower, to realize the reduction of steam consumption, simultaneously, pressurized rectifying tower and atmospheric rectifying tower are all using full reflux gas phase extraction process, last concentrated ammonia gas is directly absorbed by process water to generate concentrated ammonia water, simple structure, easy to operate, and the quality of generated ammonia water is stable.

[0044] The high ammonia-nitrogen wastewater and the deamination wastewater are added into the mixing unit, the wastewater and the lye are mixed more uniformly through the rotation of the stirring paddle, the pH value is adjusted faster and more accurately, the steam consumption is reduced through the preheating unit, and the efficiency of rectification is accelerated.The ammonia-containing steam at the top of the pressurized rectification tower is introduced into the coupled reboiler through a pipeline and is used as a heating source of the atmospheric rectification tower, the energy utilization rate is improved, the steam consumption is reduced, the energy-saving effect is obvious, and simultaneously, the pressurized rectification tower and the atmospheric rectification tower are provided with spraying devices and filler layers, the countercurrent contact area and reaction time of the high ammonia-nitrogen wastewater and the steam are increased, and the gas stripping efficiency is improved.The high ammonia-nitrogen wastewater resource treatment device provided by the utility model makes full use of the pressure difference between the pressurized rectification tower and the atmospheric rectification tower, and utilizes the different temperature differences to make the wastewater after deamination of the pressurized rectification tower not directly discharged, but flash evaporated in the kettle of the atmospheric rectification tower, the deamination wastewater delivery pump is reduced, and the heat of the system is fully utilized.

[0045] The utility model provides a high ammonia-nitrogen wastewater resource treatment device does not adopt liquid phase extraction, but is all by the form of gas phase extraction, the form of liquid phase full reflux, then realizes the recycling of concentrated ammonia water through the form of concentrated ammonia gas absorption, simple structure, easy operation.

[0046] Although the embodiments of the utility model are described in combination with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the utility model, and such modifications and changes all fall within the scope defined by the appended claims.

Claims

1. A resource-based treatment device for high ammonia nitrogen wastewater, characterized in that, include: The system comprises a mixing unit, a pressurized distillation column, a coupled reboiler, an atmospheric distillation column, a condensation unit, and an absorption column, wherein: The mixing unit includes an ammonia nitrogen wastewater inlet and an alkaline solution inlet; the outlet of the mixing unit is connected to the inlet pipe of the spray assembly at the top of the pressurized distillation column and the inlet pipe of the spray assembly at the top of the atmospheric distillation column, respectively. The pressurized distillation column is provided with a steam inlet at its lower end; the bottom of the pressurized distillation column is connected to the liquid inlet at the lower end of the atmospheric distillation column. The inlet of the coupled reboiler is connected to the top of the pressurized distillation column; the coupled reboiler serves as the heat source for the atmospheric distillation column, and the upper end of the coupled reboiler is connected to the upper and lower ends of the atmospheric distillation column via two pipes respectively. The inlet of the condensation unit is connected to the upper end of the atmospheric distillation column, and the outlet of the condensation unit is connected to the absorption column.

2. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, Also includes: A filter unit is located at the outlet of the mixing unit.

3. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 2, characterized in that, Also includes: A preheating unit is located at the outlet of the filter unit.

4. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, The mixing unit includes a stirring paddle and a pH sensor; wherein, the waste liquid in the mixing unit is stirred evenly by the stirring paddle, and if the pH sensor detects that the pH value of the waste liquid in the mixing unit is between 11.5 and 12.0, the valve of the alkaline solution sample inlet is closed.

5. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, Also includes: The first reflux tank has its inlet connected to the lower end of the coupled reboiler, and its bottom is connected to the water inlet pipe of the spray assembly of the pressurized distillation column via a pipe and a first reflux pump.

6. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, Also includes: The inlet of the second reflux tank is connected to the lower outlet of the condensation unit, and the bottom of the second reflux tank is connected to the water inlet pipe of the spray assembly of the atmospheric distillation column via a pipe and a second reflux pump.

7. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, It also includes: a discharge pool connected to the first outlet at the bottom of the atmospheric distillation column via a pipeline; a second outlet at the bottom of the atmospheric distillation column connected to the mixing unit via a pipeline pump; and a third outlet at the bottom of the atmospheric distillation column connected to the reboiler via a pipeline. If the deammoniation wastewater at the bottom of the atmospheric distillation column meets the discharge standard, the first outlet at the bottom of the atmospheric distillation column is opened for discharge; if the deammoniation wastewater at the bottom of the atmospheric distillation column does not meet the discharge standard, the second outlet at the bottom of the atmospheric distillation column is opened to pump the deammoniation wastewater into the mixing unit. The deammoniation wastewater at the bottom of the atmospheric distillation column enters the reboiler and exchanges heat with the steam from the pressurized distillation column. The steam after heat exchange enters the upper part of the atmospheric distillation column.

8. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, The top of the absorption tower is equipped with a qualified waste gas discharge outlet, and the upper end of the absorption tower is equipped with a process water inlet.

9. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 1, characterized in that, Also includes: The concentration spray assembly has its inlet pipe connected to the lower end of the absorption tower via a pipeline pump, and the spray head and packing of the concentration spray assembly are located in the middle of the absorption tower.

10. The high ammonia nitrogen wastewater resource utilization treatment device according to claim 9, characterized in that, The bottom of the absorption tower is provided with an outlet, which is connected to the concentrated ammonia product tank.

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