Pretreatment device for recycling ammonia distillation waste liquid

Abstract

The utility model discloses an ammonia distillation waste liquid recycling pretreatment device which comprises an ammonia distillation waste liquid cyclone, a waste liquid pump outlet of an ammonia distillation tower is connected with a liquid inlet of the ammonia distillation waste liquid cyclone through a waste liquid pipeline, and the waste liquid pipeline penetrates through a heat exchange device; the other liquid inlet of the ammonia distillation waste liquid cyclone is communicated with a water supply device through a water injection pipeline; and an overflow port of the ammonia distillation waste liquid cyclone is connected to a water inlet of the ash melting tank through a pipeline. The ammonia distillation wastewater treatment device solves the problem that the ammonia distillation wastewater which is just discharged cannot be quickly put into an ash melting process for cyclic utilization due to high temperature and high CaCl content.

Description

Technical Field

[0001] The utility model relates to the technical field of soda-making equipment, in particular to a pretreatment device for recycling and reusing ammonia evaporation waste liquid. Background Art

[0002] In the process flow of ammonia soda process for making soda ash, the process of adding lime milk to decompose NH4Cl in the filtered mother liquor and recovering the released ammonia gas by distillation is called ammonia evaporation. The mother liquor after releasing ammonia gas is ammonia evaporation waste liquid. At present, in order to reduce the discharge of ammonia evaporation waste liquid, it is proposed to use the ammonia evaporation waste liquid to replace part of the fresh water in the lime slaking process. However, the actual application effect is not good. Since the ammonia evaporation waste liquid has a certain temperature, it cannot be directly put into the lime slaking process for use. Moreover, there is a large amount of CaCl2 in the waste liquid, which has a great impact on the lime slaking process and cannot meet the requirements of industrial production. Summary of the Invention

[0003] Object of the Invention: In order to overcome the deficiencies in the prior art, the utility model provides a pretreatment device for recycling and reusing ammonia evaporation waste liquid, which solves the problem that the freshly discharged ammonia evaporation waste water cannot be quickly put into the lime slaking process for recycling due to its high temperature and high CaCl content.

[0004] Technical Solution: To achieve the above object, a pretreatment device for recycling and reusing ammonia evaporation waste liquid of the utility model includes an ammonia evaporation waste liquid cyclone. The waste liquid pump outlet of the ammonia evaporation tower is connected to one liquid inlet of the ammonia evaporation waste liquid cyclone through a waste liquid pipeline, and the waste liquid pipeline passes through a heat exchange device; the other liquid inlet of the ammonia evaporation waste liquid cyclone is communicated with a water supply device through a water injection pipeline; the overflow port of the ammonia evaporation waste liquid cyclone is connected to the water inlet of the lime slaking tank through a pipeline.

[0005] Further, a concentration detection device is arranged at the overflow port of the ammonia evaporation waste liquid cyclone, and the signal output end of the concentration detection device is electrically connected to the control signal receiving end of the power module of the ammonia evaporation waste liquid cyclone.

[0006] Further, a cold water device is connected in series in the water injection pipeline, and the signal output end of the temperature detection device is electrically connected to the control signal receiving end of the temperature control module of the cold water device.

[0007] Further, the heat exchange device includes two juxtaposed heat exchange pipelines. One of the heat exchange pipelines is connected to the waste liquid pipeline, and the other heat exchange pipeline is connected to the first circulation pipeline. A part of the first circulation pipeline is arranged in a steam generating device. The water inlet of the steam generating device is communicated with the water supply device through a make-up water pipeline. The steam output port at the top of the steam generating device is connected to the steam input port of the ammonia evaporation tower through a steam transmission pipeline.

[0008] Further, a heat collecting pipe is arranged in the ash dissolving tank. The heat collecting pipe is connected in a second circulation pipeline, and a part of the second circulation pipeline is arranged in the steam generating device.

[0009] Further, the two liquid inlets of the ammonia distillation waste liquid cyclone are arranged tangentially to its inner wall and are respectively arranged on opposite sides of its body.

[0010] Beneficial effects: For a pretreatment device for recycling ammonia distillation waste liquid of the present utility model, the temperature of the ammonia distillation waste liquid is initially collected through a first circulation pipeline and used to provide heat for steam generation. By adding water to mix with the waste liquid in the cyclone, the temperature of the waste liquid is further reduced, enabling a large amount of CaCl₂ to precipitate. Under the action of the cyclone, precipitation separation of CaCl₂ is achieved, and the supernatant is used as the water supply for the ash dissolving tank. The discharge amount of the waste liquid can be effectively reduced, and the ammonia distillation waste liquid can be quickly put into circulation, avoiding occupying space for waste liquid storage and cooling. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of the overall structural connection relationship of an embodiment of the present utility model. Detailed Embodiments

[0012] The present utility model will be further described in detail below with reference to the drawings.

[0013] As shown in the attached Figure 1 The pretreatment device for recycling ammonia distillation waste liquid includes an ammonia distillation waste liquid cyclone 3. The waste liquid pump outlet of the ammonia distillation tower 1 is connected to one liquid inlet of the ammonia distillation waste liquid cyclone 3 through a waste liquid pipeline 2, and the waste liquid pipeline 2 passes through a heat exchange device 4; the other liquid inlet of the ammonia distillation waste liquid cyclone 3 is communicated with a water supply device 5 through a water injection pipeline; the overflow port of the ammonia distillation waste liquid cyclone 3 is connected to the water inlet of an ash dissolving tank 6 through a pipeline.

[0014] This solution directly transports the waste liquid from the ammonia distillation column to the hydrocyclone through the waste liquid pipeline, and preliminarily cools it through a heat exchange device during the process, so that part of the CaCl2 is precipitated during transportation and enters the hydrocyclone with the liquid flow. After entering the hydrocyclone, it is further mixed with the injected fresh water to achieve further cooling. Since the solubility of CaCl2 is related to temperature, when the temperature decreases, its solubility also decreases, and the CaCl2 exceeding the solubility is quickly precipitated to form a precipitate. Under the action of the hydrocyclone, the CaCl2 precipitate moves towards the outer layer of the bottom under the action of centrifugal force and gravity, converges towards the discharge port after encountering the bottom inclined cone surface, while the waste liquid after precipitating CaCl2 is diluted with water and floats, flowing out from the upper overflow port and being transported to the lime slaking tank for use as lime slaking water supply, effectively reducing the discharge of waste liquid and ensuring the quality of lime slaking, making the waste liquid after pretreatment meet the industrial production requirements when used for lime slaking. The cooling and the removal of CaCl2 are carried out simultaneously, making the recycling of wastewater more efficient, without the need for collection, storage, and reprocessing, reducing the occupation of land resources.

[0015] A concentration detection device 10 is arranged at the overflow port of the ammonia distillation waste liquid hydrocyclone 3, and the signal output end of the concentration detection device 10 is electrically connected to the power module control signal receiving end of the ammonia distillation waste liquid hydrocyclone 3. By detecting the concentration of CaCl2 in the liquid discharged from the overflow port, the working power of the waste liquid hydrocyclone is feedback-controlled. When the concentration reaches the standard, the power can be appropriately reduced to achieve the purpose of energy saving.

[0016] A cold water device 11 is connected in series in the water injection pipeline, and the signal output end of the degree detection device 10 is electrically connected to the temperature control module control signal receiving end of the cold water device 11. Among them, the cold water device can adopt common equipment such as industrial chillers to control the temperature of the injected fresh water. Under normal treatment, when the CaCl2 concentration in the overflow liquid is still too high, by reducing the injection water temperature, enhancing the cooling effect on the waste liquid, and strengthening the precipitation of CaCl2, the output waste liquid can better meet the requirements for lime slaking use.

[0017] The heat exchange device 4 includes two juxtaposed heat exchange pipes. One of the heat exchange pipes is connected to the waste liquid pipeline 2, and the other heat exchange pipe is connected to the first circulation pipeline 7. A part of the first circulation pipeline 7 is arranged in the steam generating device 8. The water inlet of the steam generating device 8 is connected to the water supply device 5 through a make-up water pipeline, and the steam output port at the top of the steam generating device 8 is connected to the steam input port of the ammonia distillation column 1 through a steam transmission pipeline. Since steam is continuously input into the ammonia distillation column, the temperature in the column is approximately 105 - 110 °C, and the temperature of the waste liquid at the bottom of the column is also 95 - 102 °C. Heat exchange is carried out between the first circulation pipeline and the waste liquid pipeline, and the exchanged heat is transported to the steam generating device to be used for heating water to generate steam to provide heat.

[0018] A heat collecting pipe is arranged in the ash slaking tank 6. The heat collecting pipe is connected in the second circulation pipeline 9, and a part of the second circulation pipeline 9 is arranged in the steam generating device 8. Ash slaking is an exothermic process. The released heat is collected and transported through the second circulation pipeline for heating in steam generation. Among them, the parts of the first circulation pipeline and the second circulation pipeline located in the steam generating device can both be arranged in a spiral shape to facilitate uniform heating of water. In addition, the first circulation pipeline can be arranged relatively close to the water inlet of the steam generating device 8 to facilitate heat exchange with the relatively cold water, so that the water in the first circulation pipeline can release heat sufficiently after passing through the steam generating device, thereby ensuring the cooling effect on the ammonia distillation waste liquid.

[0019] The two liquid inlets of the ammonia distillation waste liquid cyclone 3 are arranged tangentially to its inner wall and are respectively arranged on opposite sides of its body. The ammonia distillation waste liquid and the injected water are injected into the cyclone interior along the tangents of the inner cavity wall in opposite directions, making the internal environment relatively stable, the mixing more uniform, the cooling effect better, contributing to the large-scale precipitation of CaCl2 and the balance of the internal swirl, and can improve the internal working temperature of the cyclone, reduce the load of its internal power module, and extend the service life of the equipment.

[0020] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A pretreatment device for recycling ammonia distillation waste liquid, characterized in that: It includes an ammonia distillation waste liquid cyclone (3). The outlet of the waste liquid pump of the ammonia distillation tower (1) is connected to an inlet of the ammonia distillation waste liquid cyclone (3) through a waste liquid pipeline (2), and the waste liquid pipeline (2) is arranged through a heat exchange device (4); the other inlet of the ammonia distillation waste liquid cyclone (3) is communicated with a water supply device (5) through a water injection pipeline; the overflow port of the ammonia distillation waste liquid cyclone (3) is connected to the water inlet of a slaking pond (6) through a pipeline.

2. The pretreatment device for recycling and utilization of ammonia distillation waste liquid according to claim 1, wherein: A concentration detection device (10) is arranged at the overflow port of the ammonia distillation waste liquid cyclone (3), and the signal output end of the concentration detection device (10) is electrically connected to the control signal receiving end of the power module of the ammonia distillation waste liquid cyclone (3).

3. The pretreatment device for recycling and utilization of ammonia distillation waste liquid according to claim 2, characterized in that: A cold water device (11) is connected in series in the water injection pipeline, and the signal output end of the concentration detection device (10) is electrically connected to the control signal receiving end of the temperature control module of the cold water device (11).

4. The pretreatment device for recycling and utilization of ammonia distillation waste liquid according to claim 3, characterized in that: The heat exchange device (4) includes two juxtaposed heat exchange pipelines. One of the heat exchange pipelines is connected into the waste liquid pipeline (2), and the other heat exchange pipeline is connected into a first circulation pipeline (7). A part of the first circulation pipeline (7) is arranged in a steam generating device (8). The water inlet of the steam generating device (8) is communicated with the water supply device (5) through a make-up water pipeline, and the steam output port at the top of the steam generating device (8) is connected to the steam input port of the ammonia distillation tower (1) through a steam transmission pipeline.

5. The pretreatment device for recycling and utilization of ammonia distillation waste liquid according to claim 4, wherein: Heat collecting pipes are arranged in the slaking pond (6), and the heat collecting pipes are connected in a second circulation pipeline (9). A part of the second circulation pipeline (9) is arranged in the steam generating device (8).

6. The pretreatment device for recycling and utilization of ammonia distillation waste liquid according to claim 5, wherein: The two inlets of the ammonia distillation waste liquid cyclone (3) are arranged tangentially to its inner wall and are respectively arranged on opposite sides of its body.

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