Evaporation energy-saving type forced effect evaporation device for alumina production

Abstract

This utility model discloses an energy-saving forced-efficiency evaporation device for alumina production, including an evaporator flash evaporator, a forced circulation separator, a primary forced-efficiency heater, a feed mother liquor inlet, a discharge mother liquor pipe, and a secondary forced-efficiency heater. After the forced-efficiency circulation evaporation device is arranged, a primary forced-efficiency heater and a secondary forced-efficiency heater are respectively set at the inlet and outlet of the forced circulation separator. The area of ​​the two forced-efficiency heaters is half of the original area. The total area of ​​the two heaters will not be reduced, but the area of ​​a single forced-efficiency heater is reduced by 50%. Therefore, the amount of mother liquor required for circulation can be reduced by about 50%, and under ideal conditions, the flow rate of the forced-efficiency circulation pump can be reduced by about 50%.

Description

Technical Field

[0001] This utility model relates to the field of alumina production equipment, and in particular to an energy-saving forced evaporation device for alumina production. Background Technology

[0002] In the alumina production process, the water volume is unbalanced due to moisture introduced from the ore, water introduced from red mud washing, and some wastewater entering during production. Therefore, the mother liquor from decomposition needs to be evaporated to remove excess water entering the process, thereby maintaining the water balance in the circulating system and ensuring that the concentration of the evaporated mother liquor meets production requirements. Currently, in the evaporation process used in alumina production, forced-effect circulating evaporation devices generally employ a forced-effect heater to heat the circulating slurry.

[0003] However, since this process uses only one forced-effect heater, the required circulating slurry flow rate and heater area are both large. The increased circulating slurry flow rate requires a larger motor power for the forced-effect circulating pump, resulting in higher power consumption and overall higher steam consumption. Summary of the Invention

[0004] The purpose of this invention is to provide an energy-saving forced-effect evaporation device for alumina production, in order to solve the problems in the prior art where only one forced-effect heater is used, resulting in a large circulating slurry flow rate and heater area required for the forced-effect heater. The increased circulating slurry flow rate also requires a larger motor power for the forced-effect circulating pump, leading to high power consumption and overall high steam consumption.

[0005] The technical solution of this utility model is as follows: An energy-saving forced evaporation device for alumina production includes a forced circulation separator, a primary forced evaporation heater, a secondary forced evaporation heater, a forced circulation pump, and an evaporation flash evaporator. The forced circulation separator is provided with a circulating slurry outlet and a discharge mother liquor pipeline. The circulating slurry outlet is connected to the evaporation flash evaporator and the secondary forced evaporation heater through a pipeline.

[0006] The forced circulation separator is connected to one end of the secondary forced effect heater via a pipeline, and the other end of the secondary forced effect heater is connected to a forced effect circulation pump. Both are connected in series with the pipeline of the evaporator flash evaporator. One end of the primary forced effect heater is connected to the forced effect circulation pump via a pipeline, and the other end is connected to the forced circulation separator via a pipeline.

[0007] Furthermore, it also includes a heating steam delivery pipe that provides heating steam to the primary forced-effect heater and the secondary forced-effect heater.

[0008] Furthermore, both the primary forced-effect heater and the secondary forced-effect heater are equipped with non-condensable gas discharge pipes that are interconnected with the forced circulation separator.

[0009] Furthermore, the forced circulation separator is connected via pipes to a four-, five-, or six-effect evaporator.

[0010] Furthermore, the required discharge mother liquor from the evaporator flash evaporator is as follows: .

[0011] Furthermore, the discharge mother liquor from the discharge mother liquor pipeline requires... .

[0012] Furthermore, the steam conveying pipe is required to deliver steam at a pressure of 0.2-0.6 MPa (absolute pressure) and a temperature of 120℃-158℃.

[0013] The beneficial effects of this utility model compared with the prior art are as follows: (1) After the arrangement of this forced-effect circulating evaporation device, a first-stage forced-effect heater and a second-stage forced-effect heater are respectively set at the inlet and outlet of the forced-effect separator. The area of ​​the two forced-effect heaters is half of the original area. The total area of ​​the two heaters will not be reduced, but the heat exchange area of ​​a single second-stage forced-effect heater is reduced by 50%. Therefore, the amount of mother liquor required for circulation can be reduced by about 50%. Under ideal conditions, the flow rate of the forced-effect circulating pump can be reduced by about 50%.

[0014] (2) After the forced-effect circulating evaporation device is arranged, the amount of circulating mother liquor that the forced-effect heater needs to process is reduced by about 50%, which can effectively reduce the amount of steam consumed by the final overall device by about 20-50%.

[0015] (3) After the forced-effect circulating evaporation device is arranged, the flow rate of the forced-effect circulating pump is effectively reduced, and the power required by the forced-effect circulating pump is reduced, saving electricity consumption and achieving the purpose of energy saving and consumption reduction. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an existing forced-efficiency evaporation device;

[0017] Figure 2 This is a schematic diagram of the energy-efficient evaporation device of this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0020] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0021] See Figure 1-2 This invention discloses an energy-saving forced-efficiency evaporation device for alumina production, comprising a forced circulation separator 1, a primary forced-efficiency heater 2, a secondary forced-efficiency heater 3, a forced-efficiency circulation pump 4, and an evaporation flash evaporator 5. The forced circulation separator 1 is provided with a circulating slurry outlet and a discharge mother liquor pipe 6. The circulating slurry outlet is interconnected with the evaporation flash evaporator 5 and the secondary forced-efficiency heater 3 through pipes. The forced circulation separator 1 is interconnected with one end of the secondary forced-efficiency heater 3 through a pipe, and the other end of the secondary forced-efficiency heater 3 is connected to the forced-efficiency circulation pump 4, both of which are interconnected with the evaporation flash evaporator 5 through pipes. One end of the primary forced-efficiency heater 2 is connected to the forced-efficiency circulation pump 4 through a pipe, and the other end is connected to the forced circulation separator 1 through a pipe.

[0022] The feed mother liquor is transported from the flash evaporator 5 to the secondary forced-effect heater 3 via a pipeline. After flowing into the circulating slurry 9 through the pipeline, the feed mother liquor from the flash evaporator 5 proceeds to the secondary forced-effect heater 3, and then enters the primary forced-effect heater 2 via the forced-effect circulating pump 4. Fresh steam or secondary steam provided by the heating steam delivery pipe 7 enters the primary forced-effect heater 2 and the secondary forced-effect heater 3 respectively via pipelines as a heating source. The heated slurry then enters the forced-effect circulating separator 1 for flash separation. The separated slurry, as the discharge mother liquor, is pumped from the discharge mother liquor pipe 6 at the bottom of the separator to the salt removal and causticizing process. The secondary steam separated by flash separation is sent from the top of the separator to the evaporator 8 for four, five, or six effects via a pipeline. During the circulation process, the non-condensable gases generated by the primary forced-effect heater 2 and the secondary forced-effect heater 3 are discharged to the forced-effect circulating separator 1 through the non-condensable gas discharge pipe, and then sent to the evaporator 8 for four, five, or six effects along with the secondary steam via pipelines.

[0023] Existing forced-effect circulating evaporation technology, such as Figure 1 The system includes a forced circulation separator, a forced-effect heater, and a forced-effect circulation pump. The feed mother liquor from the flash evaporator is piped into the circulating slurry and then pumped into a forced-effect heater. The new or secondary steam required for heating is piped into the forced-effect heater. The heated slurry enters the forced-effect circulation separator for flash separation. The separated slurry is discharged from the bottom of the separator as the discharge mother liquor and pumped to the salt removal and causticizing process. The secondary steam separated by flash separation is piped from the top of the separator to the fourth, fifth, or sixth effect evaporator. During the circulation process, the non-condensable gas generated by the forced-effect heater is piped to the forced-effect circulation separator and then sent to the fourth, fifth, or sixth effect evaporator along with the secondary steam.

[0024] Specifically, the requirements for the mother liquor inlet of the evaporator flash evaporator 5 are as follows: The requirements for the discharge mother liquor from the discharge mother liquor pipeline 6 are as follows: The materials within the set numerical range are used as raw materials for the forced effect.

[0025] Specifically, the steam conveying pipe 7 is required to convey steam at a pressure of 0.2-0.6 MPa (absolute pressure) and a temperature of 120℃-158℃. If it is fresh steam, the requirements are 0.6 MPa (absolute pressure) and 158℃; if it is secondary steam, the requirements are 0.2~0.4 MPa (absolute pressure) and 120~140℃.

[0026] In addition to the preferred embodiments described above, there are other embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection claimed by this utility model.

Claims

1. An energy-saving forced-efficiency evaporation device for alumina production, comprising a forced circulation separator (1), a primary forced-efficiency heater (2), a secondary forced-efficiency heater (3), a forced-efficiency circulation pump (4), and an evaporator flash evaporator (5), characterized in that: The forced circulation separator (1) is provided with a circulating slurry outlet and a discharge mother liquor pipe (6). The circulating slurry outlet is connected to the evaporator flash evaporator (5) and the secondary forced effect heater (3) through the pipe. The forced circulation separator (1) is connected to one end of the secondary forced effect heater (3) through a pipe, and the other end of the secondary forced effect heater (3) is connected to a forced effect circulation pump (4), and both are connected to the evaporator flash evaporator (5) through a pipe. One end of the first-stage forced-effect heater (2) is connected to the forced-effect circulation pump (4) through a pipe, and the other end is connected to the forced-effect circulation separator (1) through a pipe.

2. The energy-saving forced-efficiency evaporation device for alumina production according to claim 1, characterized in that, It also includes a heating steam delivery pipe (7) that provides heating steam to the primary forced-effect heater (2) and the secondary forced-effect heater (3).

3. An energy-saving forced-efficiency evaporation device for alumina production according to claim 1 or 2, characterized in that, Both the primary forced-effect heater (2) and the secondary forced-effect heater (3) are equipped with non-condensable gas discharge pipes (10) that are interconnected with the forced circulation separator (1).

4. The energy-saving forced evaporation device for alumina production according to claim 3, characterized in that, The forced circulation separator (1) is connected to a four-, five-, or six-effect evaporator (8) via a pipe.

5. The energy-saving forced-efficiency evaporation device for alumina production according to claim 4, characterized in that, The feed mother liquor for the evaporator flash evaporator (5) is required to be N. k (Na2O) k =200~260g / l.

6. The energy-saving forced-efficiency evaporation device for alumina production according to claim 5, characterized in that, The discharge mother liquor pipeline (6) requires N to discharge mother liquor. k (Na2O) k =260~350g / l.

7. The energy-saving forced evaporation device for alumina production according to claim 2, characterized in that, The steam conveying pipe (7) is required to deliver steam at a pressure of 0.2-0.6 MPa and a temperature of 120℃-158℃.

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