Mother liquor recycling device in aluminum oxide production process

Abstract

The invention provides a mother liquor recycling device in an aluminum oxide production process, and relates to the field of aluminum oxide production, the mother liquor recycling device comprises a filter plate with a filter layer capable of translating outwards during backwashing, and a plurality of scrapers are arranged on the filter plate in the direction facing the outer side surface of the filter layer; by arranging the filter plate capable of translating outwards, when the filter plate is subjected to backwashing cleaning, the pressure of backwashing cleaning liquid is utilized to push the filter layer to translate outwards, and the scraper blade is used for automatically cleaning the filter layer, so that the filter layer is prevented from being scraped, and the cleaning efficiency is improved. The cleaning effect on the filter plate in the backwashing process can be effectively improved, the downtime of equipment is reduced, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of alumina production, in particular to a mother liquor recycling device in the alumina production process. BACKGROUND

[0002] In the alumina production mother liquor recycling process, after the mother liquor is settled and filtered in the settling tank, a leaf filter is used to deeply filter the thick liquid output from the settling tank to remove small particle impurities and obtain pure sodium aluminate solution (referred to as "fine liquid"). However, when the filter plate in the leaf filter is backwashed and cleaned, the backwashing cannot completely remove the residual impurities adhered to the surface of the filter plate. The residual impurities are difficult to clean and scrape off by machines or manually, and the long equipment downtime also affects production. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a mother liquor recycling device in the alumina production process, which can effectively improve the cleaning effect of the filter plate during backwashing, reduce the equipment downtime, and improve the production efficiency by setting a filter plate capable of translating outwardly, using the pressure of the cleaning liquid for backwashing to push the filter layer outwardly and using a scraper to automatically clean the filter layer.

[0004] To achieve the above purpose, the present application realizes the following technical scheme: a mother liquor recycling device in the alumina production process, comprising a filter plate capable of translating outwardly during backwashing, and a plurality of scrapers are arranged on the outer side of the filter plate facing the filter layer. When the filter layer translates outwardly, the scrapers can be deformed in contact with the filter layer and slide on the outer side of the filter layer.

[0005] Preferably, the filter layer edge and the filter plate edge are sealingly connected with an elastic band.

[0006] Preferably, the cross section of the scraper is circular arc-shaped, the contact end of the scraper and the filter layer is circular arc-shaped, and the scraper is U-shaped in the top view.

[0007] Preferably, the two ends of the scraper are fixedly installed on the outer side of the vertical plate, and the vertical plate is fixedly connected to the outer side of the filter plate through the mounting plate.

[0008] Preferably, the sliding distance of the scraper on the filter layer is greater than the distance between adjacent scrapers.

[0009] As a preferred embodiment of the mother liquor recycling device in the alumina production process of the present invention, a plurality of positioning components are fixedly installed on the inner side of the filter plate. The positioning components include a housing and a movable rod fixedly connected to the inner side of the housing. The movable rod is slidably connected to the inner side of the housing.

[0010] As a preferred embodiment of the mother liquor recycling device in the alumina production process of the present invention, the movable end of the moving rod located inside the housing is fixedly connected to a limiting plate.

[0011] As a preferred embodiment of the mother liquor recycling device in the alumina production process of the present invention, two shells at the same height are fixedly connected by a connecting rod, and the two ends of the connecting rod are fixedly connected to the inner side of the filter plate.

[0012] As a preferred embodiment of the mother liquor recycling device in the alumina production process of the present invention, a tension spring is also provided on the inner side of the shell, and the movable end of the tension spring is fixedly connected to the moving rod.

[0013] As a preferred embodiment of the mother liquor recycling device in the alumina production process of the present invention, the moving rod and tension spring on the inner side of the shell are arranged alternately.

[0014] Compared with the prior art, the present invention has the following beneficial effects: By setting up a filter plate whose filter layer can move outward, the pressure of the backwash filtrate is used to push the filter layer outward during backwashing and cleaning, and a scraper is used to automatically clean the filter layer. This can effectively improve the cleaning effect of the filter plate during backwashing, reduce equipment downtime, and increase production efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the filter layer after it has been translated from the filter plate according to the present invention; Figure 3 This is a cross-sectional view of the filter plate of the present invention; Figure 4 This is a schematic diagram of the connection structure between the scraper and the vertical plate of the present invention; Figure 5 This is a cross-sectional view of the housing of the present invention; Figure 6 This is a schematic diagram of the scraper structure of the present invention.

[0016] The components are: 1. Filter layer; 2. Filter plate; 3. Scraper; 4. Telescopic belt; 5. Vertical plate; 6. Mounting plate; 7. Positioning component; 71. Housing; 72. Moving rod; 73. Tension spring; 8. Connecting rod. Detailed Implementation

[0017] like Figures 1-6As shown, a mother liquor recycling device in alumina production includes a filter plate 2 whose filter layer 1 can be moved outward during backwashing. Multiple scrapers 3 are arranged on the filter plate 2 facing the outer surface of the filter layer 1. When the filter layer 1 moves outward, the scrapers 3 can deform against the filter layer 1 and slide on its outer surface. During backwashing, clean filtrate (or demineralized water) is introduced in reverse from the filtrate outlet of the filter plate, using water pressure to peel the filter cake off the surface of the filter layer 1. After backwashing, some residue will still remain on the surface of the filter layer 1. Figure 2 As shown, by setting a filter layer 1 that can move on the filter plate 2, when the backwash filtrate enters the inner side of the filter plate 2, the pressure of the backwash filtrate can push the filter layers 1 on both sides of the filter plate 2 to move outward at the moment of entry into the filter plate 2. During the movement, the backwash filtrate will flow outward from the inner side of the filter layer 1, thereby washing off the impurities adsorbed on the surface of the filter layer 1. When the filter layer 1 comes into contact with the scraper 3, the filter layer 1 can push the scraper 3 to deform. At this time, the filter layer 1 continues to move outward. When the scraper 3 is deformed, it can slide along the outer side of the filter layer 1, thereby scraping off the impurities on the surface of the filter layer 1. This method can directly scrape and wash the outer surface of the filter layer 1 while backwashing the filter plate 2, effectively improving the cleaning effect of the filter layer 1, reducing equipment downtime, and improving production efficiency.

[0018] Furthermore, In an optional embodiment, a telescopic belt 4 is provided to seal the edge of the filter layer 1 and the edge of the filter plate 2. When the filter layer 1 moves outward, it will detach from the filter plate 2. Therefore, it is necessary to keep the connection between the filter layer 1 and the filter plate 2 sealed and stable. If the telescopic belt 4 is not provided, a gap will be created between the filter layer 1 and the filter plate 2 after the filter layer 1 moves outward. The backwash filtrate will flow out from the gap between the filter layer 1 and the filter plate 2, which will not achieve the rinsing effect on the filter layer 1. The telescopic belt 4 can extend and retract and fold, which can connect the filter layer 1 and the filter plate 2 to each other. After the filter layer 1 is rinsed, it can be folded and attached to the side of the filter plate 2 again, so as to facilitate the backwashing and cleaning of the filter layer 1 again.

[0019] In an optional embodiment, the scraper 3 has an arc-shaped cross-section, and the contact end between the scraper 3 and the filter layer 1 is also arc-shaped. In a top view, the scraper 3 appears U-shaped. The arc-shaped scraper 3 faces the filter layer 1 at a certain angle when not in contact with it. When the filter layer 1 moves and contacts the scraper 3, the pressure from the filter layer 1 causes the scraper 3 to deform, allowing it to slide across the surface of the filter layer 1 and scrape away impurities. The arc-shaped contact end between the scraper 3 and the filter layer 1 ensures stable contact with the filter layer 1 while minimizing damage to it. To prevent scraper 3 from damaging filter layer 1, when scraper 3 scrapes off impurities on filter layer 1, the impurities will slide down along the upper surface of scraper 3. At this time, if scraper 3 is a complete arc-shaped plate, impurities may accumulate on scraper 3, causing impurities to block between adjacent scrapers 3. By setting scraper 3 to U-shape, the area of ​​scraper 3 can be greatly reduced. After scraper 3 scrapes off impurities, the scraped impurities are unlikely to stay above the already tilted scraper 3. Instead, they fall directly along the U-shaped groove on scraper 3 with the flushing of backwash filtrate, thus avoiding impurities from blocking between scrapers 3.

[0020] In an optional embodiment, the scraper 3 is fixedly installed on the outer side of the upright plate 5 at both ends. The upright plate 5 is fixedly connected to the outer side of the filter plate 2 by the mounting plate 6. The upright plate 5 and the mounting plate 6 can fix the scraper 3 to the filter plate 2, instead of fixing the scraper 3 to the housing 71 of the leaf filter. This can reduce the installation volume of the mounting plate 6 and save costs.

[0021] In an optional embodiment, the sliding distance of the scraper 3 on the filter layer 1 is greater than the distance between adjacent scrapers 3. Since the translational distance of the filter layer 1 on the filter plate 2 is limited, the sliding distance of the scraper 3 on the filter plate 2 is also limited. If the sliding distance of the scraper 3 on the filter layer 1 is less than the distance between adjacent scrapers 3, it will cause the adjacent scrapers 3 to leave strip-shaped cleaning dead corners after translating and cleaning on the filter layer 1, which cannot completely cover the entire filter layer 1. Only when the sliding distance of the scraper 3 on the filter layer 1 is greater than the distance between adjacent scrapers 3 can each scraper 3 completely clean the surface of the filter layer 1 and maintain the cleaning effect on the filter layer 1. It should be noted that during the normal filtration of impurities by the filter plate 2, the scraper 3 does not contact the filter layer 1. Only when the filter plate 2 is backwashed will the filter layer 1 contact the scraper 3 under the pressure of the filtrate.

[0022] In an optional embodiment, a plurality of positioning elements 7 are fixedly installed on the inner side of the filter plate 2. The positioning element 7 includes a housing 71 and a movable rod 72 fixedly connected to the inner side of the housing 71. The movable rod 72 is slidably connected to the inner side of the housing 71. The housing 71 can support the movable rod 72 and keep the moving direction of the movable rod 72 stable, so that after the backwash filtrate enters the inner side of the filter plate 2, it can push the filter layer 1 to move smoothly to both sides of the filter plate 2. It should be noted that in order to maintain the stability of the movable rod 72 supporting the filter plate 2, the movable rod 72 can be evenly distributed at the four corners near the filter layer 1.

[0023] In an optional embodiment, a limiting plate is fixedly connected to the movable end of the moving rod 72 located inside the housing 71. The limiting plate can slide along the moving rod 72 inside the housing 71. At the same time, when the moving rod 72 moves out of the housing 71 by the maximum distance, the limiting plate can limit the position of the moving rod 72 to prevent the moving rod 72 from falling out of the housing 71.

[0024] In an optional embodiment, two housings 71 at the same height are fixedly connected by a connecting rod 8. The two ends of the connecting rod 8 are fixedly connected to the inner side of the filter plate 2. The connecting rod 8 is fixedly connected in the filter plate 2. The connecting rod 8 and the housing 71 are fixedly connected, thereby providing fixed support for the housing 71 and maintaining the stability of the housing 71.

[0025] In an optional embodiment, a tension spring 73 is also provided on the inner side of the housing 71. The movable end of the tension spring 73 is fixedly connected to the moving rod 72. After the filter layer 1 is moved outward, the tension spring 73 can pull the moving rod 72 and the filter layer 1 to move backward and reset automatically, so that the filter layer 1 moves again and presses against the filter plate 2, which facilitates the use of backwash filtrate to clean the surface of the filter layer 1 again.

[0026] In an optional embodiment, the movable rod 72 and tension spring 73 inside the housing 71 are staggered. Since the thickness of the filter plate 2 is limited, and the movable rod 72 needs to move in a direction parallel to the thickness of the filter plate 2, in order to ensure that the movable rod 72 can drive the filter layer 1 to translate outward by a sufficient distance, the staggered movable rod 72 can maximize the translation distance of the filter layer 1 without changing the thickness of the filter plate 2. Of course, if the thickness of the filter plate 2 is sufficient to support the translation distance of the movable rod 72 and the filter layer 1, the movable rod 72 in the same housing 71 can also be arranged on the same axis. This embodiment is only one implementation method.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mother liquor recycling device in alumina production process, characterized in that: The filter includes a filter plate (2) that can move outward during backwashing of the filter layer (1). Multiple scrapers (3) are provided on the filter plate (2) in the direction facing the outer side of the filter layer (1). When the filter layer (1) moves outward, the scrapers (3) can collide with and deform the filter layer (1) and slide on the outer side of the filter layer (1).

2. The mother liquor recycling device in the alumina production process according to claim 1, characterized in that: An elastic band (4) is used to seal the connection between the edge of the filter layer (1) and the edge of the filter plate (2).

3. The mother liquor recycling device in the alumina production process according to claim 1, characterized in that: The cross section of the scraper (3) is arc-shaped, and the contact end between the scraper (3) and the filter layer (1) is arc-shaped. When viewed from above, the scraper (3) is U-shaped.

4. The mother liquor recycling device in the alumina production process according to claim 3, characterized in that: The scraper (3) is fixedly installed on the outer side of the vertical plate (5) at both ends, and the vertical plate (5) is fixedly connected to the outside of the filter plate (2) through the mounting plate (6).

5. A mother liquor recycling device in the alumina production process according to claim 3 or 4, characterized in that: The sliding distance of the scraper (3) on the filter layer (1) is greater than the distance between adjacent scrapers (3).

6. The mother liquor recycling device in the alumina production process according to claim 1, characterized in that: Multiple positioning components (7) are fixedly installed on the inner side of the filter plate (2). The positioning component (7) includes a housing (71) and a moving rod (72) fixedly connected to the inner side of the housing (71). The moving rod (72) is slidably connected to the inner side of the housing (71).

7. The mother liquor recycling device in the alumina production process according to claim 6, characterized in that: A limiting plate is fixedly connected to the movable end of the moving rod (72) located inside the housing (71).

8. The mother liquor recycling device in the alumina production process according to claim 6, characterized in that: Two housings (71) at the same height are fixedly connected by a connecting rod (8), with both ends of the connecting rod (8) fixedly connected to the inside of the filter plate (2).

9. A mother liquor recycling device in alumina production process according to claim 6 or 7, characterized in that: A tension spring (73) is also provided on the inner side of the housing (71), and the movable end of the tension spring (73) is fixedly connected to the moving rod (72).

10. A mother liquor recycling device in alumina production process according to claim 9, characterized in that: The movable rod (72) and tension spring (73) inside the housing (71) are arranged alternately.

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