CN215984156U

CN215984156U - Heat recovery system for alumina decomposition process

Info

Publication number: CN215984156U
Application number: CN202122529913.0U
Authority: CN
Inventors: 李蒙蒙
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2022-03-08
Anticipated expiration: 2031-10-20

Abstract

The utility model belongs to the technical field of alumina production processes, and particularly relates to a heat recovery system for an alumina decomposition process; it comprises a decomposition tank, a filter and a heat exchange device; the discharge end of the decomposition tank is communicated with the feed end of the filter; the heat exchange device comprises a conveying pipe, the liquid inlet end of the conveying pipe is communicated with the liquid outlet of the filter, and the liquid outlet end of the conveying pipe penetrates through the decomposition tank and is communicated to an evaporation workshop. The heat exchanger in the heat recovery system for the alumina decomposition process can absorb the heat of high-temperature semen in the decomposition tank by utilizing the mother liquor separated by the filter, so that the heat in the high-temperature semen is replaced and sufficiently and reasonably utilized, the loss of heat energy is effectively reduced, and the production cost of alumina is reduced.

Description

Heat recovery system for alumina decomposition process

Technical Field

The utility model belongs to the technical field of alumina production processes, and particularly relates to a heat recovery system for an alumina decomposition process.

Background

At present, in the production of alumina, a decomposition workshop exchanges heat between refined liquid (sodium aluminate solution) separated and filtered in a red mud workshop and mother liquid separated by a filter, then the refined liquid is mixed with decomposed and precipitated solid aluminum hydroxide, then the mixture is sent into a decomposition tank together for cooling, and the aluminum hydroxide is precipitated after the mixture stays in the decomposition tank for a certain time.

The cooling process (see figure 1) mainly utilizes cold water in a water cooling tower to absorb the temperature of a mixture of high-temperature solid (aluminum hydroxide) and liquid (refined liquid) in a decomposition tank, then sends the high-temperature water absorbing heat into a cooling tower, and exchanges heat with the high-temperature water through air so that the temperature of the high-temperature water is reduced and the high-temperature water is recycled, thus the heat of the mixture in the decomposition tank is continuously taken out in a circulating manner, the cooling process in the decomposition tank can be carried out smoothly, and the process control condition of decomposition is ensured.

In the heat exchange process of the mixture and cooling water, the decomposition temperature is generally reduced from 59-70 ℃ of the first tank to 43-51 ℃, so that the loss of heat at 8-16 ℃ occurs, the part of heat is mainly brought out by wind and water vapor, the part of heat is not fully utilized, and the loss of water caused by the gasification of the cooling water into air can be caused, so that the production cost of the aluminum oxide is increased. Therefore, the utility model of a heat recovery system capable of fully utilizing the heat of high-temperature semen is a technical problem to be solved urgently by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems in the prior art, the present invention provides a heat recovery system for an alumina decomposition process, so as to solve the technical problem of heat energy loss caused by insufficient utilization of heat in the alumina decomposition process in the prior art.

The utility model is realized by the following technical scheme:

a heat recovery system for an alumina decomposition process comprises a decomposition tank, a filter and a heat exchange device;

the discharge end of the decomposition tank is communicated with the feed end of the filter;

the heat exchange device comprises a conveying pipe, the liquid inlet end of the conveying pipe is communicated with the liquid outlet of the filter, and the liquid outlet end of the conveying pipe penetrates through the decomposition tank and is communicated to an evaporation workshop.

In order to better implement the utility model, in the above structure, it is further optimized that the heat exchange end of the conveying pipe is arranged around the inner side wall of the decomposition tank.

In order to better implement the utility model, the structure is further optimized, and the heat exchange end of the conveying pipe is of a spiral structure.

In order to better realize the utility model, the structure is further optimized, the heat exchange device further comprises a heat exchanger A and a circulating pump, the water inlet end of the heat exchanger A and the water outlet end of the heat exchanger A are both communicated with the decomposition tank, the circulating pump is arranged at the water inlet end of the heat exchanger A, and the liquid outlet end of the conveying pipe penetrates through the heat exchanger A and is communicated with an evaporation workshop.

In order to better realize the utility model, the structure is further optimized, a liquid outlet of the filter is provided with a liquid conveying pump, and the liquid outlet of the filter is communicated with the liquid inlet end of the conveying pipe through the liquid conveying pump.

In order to better realize the utility model, the structure is further optimized, the heat recovery system of the alumina decomposition process further comprises a heat dissipation system, the decomposition tank comprises a heat absorption tank and a heat dissipation tank, the discharge end of the heat absorption tank is communicated with the filter through the heat dissipation tank, the heat exchanger A is communicated with the heat absorption tank, and the heat dissipation system is communicated with the heat dissipation tank.

In order to better realize the utility model, the structure is further optimized, the heat dissipation system comprises a cooling tower, a circulation pipeline and a heat exchanger B, the water outlet end of the cooling tower is communicated with the water inlet end of the circulation pipeline through a water delivery pump, the water outlet end of the circulation pipeline is communicated with the water inlet end of the cooling tower through the heat exchanger B, the heat dissipation groove is provided with a heat dissipation inlet and a heat dissipation outlet, the heat dissipation inlet is communicated with the heat dissipation outlet through the heat exchanger B, and the heat dissipation outlet is provided with a heat dissipation pump.

In order to better realize the utility model, the structure is further optimized, the number of the heat absorption tanks is multiple, the number of the heat exchangers a is equal to that of the heat absorption tanks, all the heat exchangers a are communicated with all the heat absorption tanks in a one-to-one correspondence manner, and the liquid outlet end of the conveying pipe sequentially penetrates through all the heat exchangers a and is communicated to an evaporation workshop.

In order to better realize the utility model, the structure is further optimized, the heat recovery system of the alumina decomposition process further comprises a feed pipe and a heat exchanger C, the feed pipe penetrates through the heat exchanger C to be communicated with the decomposition tank, and the liquid outlet end of the conveying pipe penetrates through the heat exchanger C to be communicated with an evaporation plant.

In order to better implement the utility model, the structure is further optimized, and the heat recovery system for the alumina decomposition process further comprises a solid pipeline, wherein the filter is communicated with the feeding pipe through the solid pipeline.

In summary, the present invention has the following technical effects:

the heat exchanger in the heat recovery system for the alumina decomposition process can absorb the heat of high-temperature semen in the decomposition tank by utilizing the mother liquor separated by the filter, so that the heat in the high-temperature semen is utilized fully and reasonably, the loss of heat energy is effectively reduced, and the production cost of alumina is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a cooling process for high-temperature semen in the prior art;

FIG. 2 is a schematic diagram of a heat recovery system for an alumina decomposition process according to an embodiment;

FIG. 3 is a schematic view of a duct structure of a heat recovery system of an alumina decomposition process according to an embodiment;

FIG. 4 is a schematic view of the heat recovery system of the alumina decomposition process according to the second embodiment;

FIG. 5 is a schematic view of a heat recovery system for an alumina decomposition process according to the second embodiment, in which a duct passes through a plurality of heat exchangers A.

Reference numerals:

1. a decomposition tank; 11. a heat absorption tank; 12. a heat sink; 2. a filter; 3. a heat exchange device; 31. a delivery pipe; 32. a heat exchanger A; 33. a circulation pump; 4. an infusion pump; 51. a cooling tower; 52. a circulation line; 53. A heat exchanger B; 54. a water delivery pump; 55. a heat dissipation pump; 61. a feed pipe; 62. a heat exchanger C; 7. a solid pipeline.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the utility model, and not restrictive of the full scope of the utility model. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

In the description of the present invention, it is to be noted that "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing and simplifying the description, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus are not to be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.

The first embodiment is as follows:

as shown in fig. 2 and 3:

a heat recovery system for an alumina decomposition process comprises a decomposition tank 1, a filter 2 and a heat exchange device 3; wherein the content of the first and second substances,

the discharge end of the decomposition tank 1 is communicated with the feed end of the filter 2;

the heat exchange device 3 comprises a conveying pipe 31, the liquid inlet end of the conveying pipe 31 is communicated with the liquid outlet of the filter 2, and the liquid outlet end of the conveying pipe 31 penetrates through the decomposition tank 1 and is communicated to an evaporation workshop.

Preferably, the heat exchange end of the conveying pipe 31 is arranged around the inner side wall of the decomposition tank 1; the conveyer pipe 31 of this structure can effectually increase the time of mother liquor through decomposer 1 and the area of contact of seminal fluid in conveyer pipe 31 and the decomposer 1 to the heat transfer effect of effectual improvement seminal fluid and mother liquor.

It should be noted that the heat exchange end of the delivery pipe 31 refers to the part of the delivery pipe 31 inside the decomposition tank 1, and the part can directly contact with the semen inside the decomposition tank 1, so as to realize the heat exchange between the mother liquor inside the delivery pipe 31 and the semen inside the decomposition tank 1.

Preferably, the heat exchange end of the conveying pipe 31 is of a spiral structure, the heat exchange end of the spiral structure can further improve the contact area between the heat exchange end of the conveying pipe 31 and the refined liquid in the decomposition tank 1, and the stroke of the mother liquid and the time for the mother liquid to flow through the decomposition tank 1 can be effectively increased, so that the heat recovery efficiency of the heat recovery system of the alumina decomposition process is further improved.

Preferably, the heat recovery system for the alumina decomposition process also comprises a feeding pipe 61, a heat exchanger C62 and a solid pipeline; wherein the content of the first and second substances,

the feeding pipe 61 passes through the heat exchanger C62 to be communicated with the decomposition tank 1, the liquid outlet end of the conveying pipe 31 passes through the heat exchanger C62 and is communicated with an evaporation plant, and part of solids separated by the filter 2 can enter the feeding pipe 61 through a solid pipeline and are mixed with the refined liquid in the feeding pipe 61 to enter the decomposition tank 1.

In the production of alumina, the high-temperature refined liquid separated from the decomposition workshop enters a heat exchanger C62 through a feeding pipe 61 and exchanges heat with the low-temperature mother liquid separated from the filter 2 in a heat exchanger C62;

the low-temperature mother liquor can continuously enter an evaporation workshop through the conveying pipe 31 to carry out the next step after absorbing heat in the refined liquid, the cooled refined liquid can enter the decomposition tank 1 through the feeding pipe 61, and meanwhile, part of aluminum hydroxide solids separated out in the filter 2 can be mixed with the cooled refined liquid at the communication position of the feeding pipe 61 and the decomposition tank 1 through a solid pipeline and enter the decomposition tank 1 together;

at this time, the mother liquor separated by the filter 2 can exchange heat with the refined liquor in the decomposition tank 1 when passing through the heat exchange end of the conveying pipe 31, so that the temperature of the refined liquor is gradually reduced, aluminum hydroxide is precipitated, and then the refined liquor is conveyed to the filter 2 from the decomposition tank 1 to separate out the mother liquor and aluminum hydroxide solids.

The mother liquor separated by the filter 2 can be used as a cold medium of the refined liquid to reduce the using amount of cooling water, part of the aluminum hydroxide solid can be mixed with the refined liquid in the feeding pipe 61 through the solid pipeline, and the other part of the aluminum hydroxide solid can be sent to a roasting workshop to carry out the next process. The heat of the high-temperature semen separated from the decomposition workshop in the heat recovery system for the alumina decomposition process can be repeatedly utilized to reduce the loss of the heat in the semen, so that the loss of the heat energy is effectively reduced, and the production cost of the alumina is reduced.

Example two:

as shown in fig. 4 and 5:

Preferably, the heat exchange device 3 further comprises a heat exchanger a32 and a circulating pump 33; wherein the content of the first and second substances,

the water inlet end of the heat exchanger A32 and the water outlet end of the heat exchanger A32 are both communicated with the decomposition tank 1, the circulating pump 33 is arranged at the water inlet end of the heat exchanger A32, the water outlet end of the conveying pipe 31 penetrates through the heat exchanger A32 and is communicated to an evaporation workshop, and the heat exchange end of the conveying pipe 31 is positioned in the heat exchanger A32;

the circulation pump 33 can pump the semen in the decomposition tank 1 into the heat exchanger A32, while the mother liquor separated by the filter 2 can enter the heat exchanger A32 through the delivery pipe 31 and exchange heat with the high-temperature semen in the heat exchanger A32; the refined liquid after heat exchange can flow back to the decomposition tank 1 from the water outlet end of the heat exchanger A32, and flow to the filter 2 through the decomposition tank 1 to separate the solid (aluminum hydroxide) and the liquid (mother liquid).

Optimally, a liquid outlet of the filter 2 is provided with a liquid conveying pump 4, and the liquid outlet of the filter 2 is communicated with the conveying pipe 31 through the liquid conveying pump 4; the liquid transfer pump 4 can provide power for the mother liquor separated by the filter 2, so that the mother liquor can enter an evaporation plant through the conveying pipe 31.

Preferably, the heat recovery system of the alumina decomposition process further comprises a heat dissipation system, the decomposition tank 1 comprises a heat absorption tank 11 and a heat dissipation tank 12, wherein,

the discharge end of the heat absorption tank 11 is communicated with the filter 2 through a heat dissipation tank 12, a heat exchanger A32 is communicated with the heat absorption tank 11, and a heat dissipation system is communicated with the heat dissipation tank 12.

Preferably, the heat dissipation system comprises a cooling tower 51, a circulating pipeline 52 and a heat exchanger B53; wherein the content of the first and second substances,

the water outlet end of the cooling tower 51 is communicated with the water inlet end of the circulating pipeline 52 through the water delivery pump 54, and the water outlet end of the circulating pipeline 52 is communicated with the water inlet end of the cooling tower 51 through the heat exchanger B53; the heat dissipation groove 12 is provided with a heat dissipation inlet and a heat dissipation outlet, the heat dissipation inlet and the heat dissipation outlet are communicated through a heat exchanger B53, and the heat dissipation outlet is provided with a heat dissipation pump 55;

the heat-radiating pump 55 can suck the semen in the heat-radiating groove 12 into the heat exchanger B53 and exchange heat with the cooling water in the circulating pipeline 52 in the heat exchanger B53 so as to further reduce the temperature of the semen to reach the range for making low-temperature mother liquor.

In addition, the circulation line 52 may have the same structure as the delivery pipe 31 described in the first embodiment, and the heat exchange end of the circulation line 52 may be arranged in a ring shape and extend into the heat sink 12, so that the use of the heat exchanger B53 and the heat sink pump 55 may be omitted, thereby further reducing the production cost of alumina.

Preferably, the number of the heat absorption tanks 11 is multiple, the number of the heat exchangers a32 is equal to that of the heat absorption tanks 11, all the heat exchangers a32 are communicated with all the heat absorption tanks 11 in a one-to-one correspondence manner, and the liquid outlet end of the conveying pipe 31 sequentially penetrates through all the heat exchangers a32 and is communicated with an evaporation workshop.

In the production of the alumina, the high-temperature refined liquid separated from the decomposition workshop enters a heat exchanger C62 through a feeding pipe 61, the temperature of the refined liquid entering the heat exchanger C62 is about 100-106 ℃, and the refined liquid exchanges heat with the low-temperature mother liquid separated from the filter 2 in a heat exchanger C62;

the low-temperature mother liquor can continuously enter an evaporation workshop through the conveying pipe 31 to carry out the next step after absorbing heat in the refined liquid, the cooled refined liquid can enter the decomposition tank 1 through the feeding pipe 61, the temperature of the refined liquid entering the decomposition tank 1 is about 57-70 ℃, and meanwhile, part of aluminum hydroxide solids separated out from the filter 2 can be mixed with the cooled refined liquid at the communication position of the feeding pipe 61 and the decomposition tank 1 through a solid pipeline and enter the first heat absorption tank 11 together.

Then, the semen in the heat absorption grooves 11 exchanges heat with the mother liquor separated by the separator under the action of the heat exchange device 3 to further absorb heat brought out by the semen, and the temperature of the semen can be gradually reduced by the arrangement of the heat absorption grooves 11 until the heat in the semen cannot be replaced by the mother liquor, and the semen in the heat absorption grooves 11 flows into the heat dissipation grooves 12;

the semen in the heat dissipation groove 12 can exchange heat with cooling water in a heat dissipation system through a heat exchanger B53, and the heat of the semen in the heat dissipation groove 12 is absorbed through cold water in the cooling tower 51, so that the temperature of the semen is reduced to 43-51 ℃, and the purpose of cooling and precipitating aluminum hydroxide is achieved;

and then the refined liquid in the last heat dissipation groove 12 and the aluminum hydroxide solid are sent into a separator together for solid-liquid separation to obtain low-temperature mother liquid and the aluminum hydroxide solid.

The separated mother liquor can be used as a cold medium of the refined liquid to reduce the usage amount of cooling water, part of the aluminum hydroxide solids can be mixed with the refined liquid in the feeding pipe 61 through a solid pipeline, and the other part of the aluminum hydroxide solids can be sent to a roasting workshop for the next process. The heat of the high-temperature semen separated from the decomposition workshop in the heat recovery system of the alumina decomposition process can be repeatedly utilized, so that the loss of the heat in the semen is reduced, the loss of the heat energy is effectively reduced, and the production cost of the alumina is reduced.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A heat recovery system for an alumina decomposition process is characterized in that: comprises a decomposition tank (1), a filter (2) and a heat exchange device (3);

the discharge end of the decomposition tank (1) is communicated with the feed end of the filter (2);

the heat exchange device (3) comprises a conveying pipe (31), the liquid inlet end of the conveying pipe (31) is communicated with the liquid outlet of the filter (2), and the liquid outlet end of the conveying pipe (31) penetrates through the decomposition tank (1) and is communicated to an evaporation workshop.

2. The alumina decomposition process heat recovery system of claim 1, wherein: the heat exchange end of the conveying pipe (31) is arranged around the inner side wall of the decomposition tank (1).

3. The alumina decomposition process heat recovery system of claim 2, wherein: the heat exchange end of the conveying pipe (31) is of a spiral structure.

4. The alumina decomposition process heat recovery system of claim 1, wherein: the heat exchange device (3) further comprises a heat exchanger A (32) and a circulating pump (33), the water inlet end of the heat exchanger A (32) and the water outlet end of the heat exchanger A (32) are communicated with the decomposition tank (1), the circulating pump (33) is arranged at the water inlet end of the heat exchanger A (32), and the liquid outlet end of the conveying pipe (31) penetrates through the heat exchanger A (32) and is communicated to an evaporation workshop.

5. The alumina decomposition process heat recovery system of claim 4, wherein: the liquid outlet of the filter (2) is provided with a liquid conveying pump (4), and the liquid outlet of the filter (2) is communicated with the liquid inlet end of the conveying pipe (31) through the liquid conveying pump (4).

6. The alumina decomposition process heat recovery system of claim 5, wherein: the decomposition tank (1) comprises a heat absorption tank (11) and a heat dissipation tank (12), the discharge end of the heat absorption tank (11) is communicated with the filter (2) through the heat dissipation tank (12), the heat exchanger A (32) is communicated with the heat absorption tank (11), and the heat dissipation system is communicated with the heat dissipation tank (12).

7. The alumina decomposition process heat recovery system of claim 6, wherein: the heat dissipation system comprises a cooling tower (51), a circulation pipeline (52) and a heat exchanger B (53), wherein the water outlet end of the cooling tower (51) is communicated with the water inlet end of the circulation pipeline (52) through a water delivery pump (54), the water outlet end of the circulation pipeline (52) is communicated with the water inlet end of the cooling tower (51) through the heat exchanger B (53), a heat dissipation inlet and a heat dissipation outlet are formed in the heat dissipation groove (12), the heat dissipation inlet is communicated with the heat dissipation outlet through the heat exchanger B (53), and a heat dissipation pump (55) is arranged at the heat dissipation outlet.

8. The alumina decomposition process heat recovery system of claim 7, wherein: the number of the heat absorption tanks (11) is multiple, the number of the heat exchangers A (32) is equal to that of the heat absorption tanks (11), all the heat exchangers A (32) are communicated with all the heat absorption tanks (11) in a one-to-one correspondence mode, and liquid outlet ends of the conveying pipes (31) sequentially penetrate through all the heat exchangers A (32) and are communicated to an evaporation workshop.

9. The alumina decomposition process heat recovery system of any one of claims 1 to 8, wherein: the device also comprises a feeding pipe (61) and a heat exchanger C (62), wherein the feeding pipe (61) penetrates through the heat exchanger C (62) to be communicated with the decomposition tank (1), and the liquid outlet end of the conveying pipe (31) penetrates through the heat exchanger C (62) and is communicated to an evaporation plant.

10. The alumina decomposition process heat recovery system of claim 9, wherein: still include solid pipeline (7), filter (2) pass through solid pipeline (7) with inlet pipe (61) intercommunication.