Recovery system for waste alkali liquor of pot mold

Abstract

The utility model relates to a pot mold waste alkali liquor recovery system which comprises pot mold grooves, a waste alkali liquor collecting groove, a crystallization reaction tower, a crystal filtering groove, a recycled alkali liquor barrel, a centrifugal machine and a separated liquid barrel, each pot mold groove is communicated with the waste alkali liquor collecting groove through a collecting pipe, and the waste alkali liquor collecting groove is communicated with the crystallization reaction tower through a waste alkali liquor lifting pipe. One side of the top of the crystallization reaction tower is provided with an overflow pipe inserted into the crystal filtering groove, the bottom of the crystal filtering groove is provided with a liquid guide pipe inserted into the recycled alkali liquor barrel, and the bottom of the side surface of the recycled alkali liquor barrel is provided with a liquid distribution pipe for respectively feeding recycled alkali liquor into each pot mold groove; one side of the bottom of the crystallization reaction tower is communicated with a mixed liquid inlet of the centrifugal machine through a mixed liquid conveying pipe, a separation liquid conveying pipe inserted into a separation liquid barrel is mounted on the side surface of the centrifugal machine, and the separation liquid barrel is communicated with the crystallization reaction tower through a separation liquid lifting pipe. The system has the beneficial effects that the system structure is simplified, sodium hydroxide crystal particles discharged into the crystal filter tank are reduced, and the cleaning frequency of the crystal filter tank is reduced.

Description

Technical Field

[0001] This utility model relates to the field of alkali recovery equipment, and in particular to a system for recovering waste alkali from mold boiling. Background Technology

[0002] The extrusion molds used in aluminum profile production often have aluminum material adhering to them. After use, the molds are typically suspended in a boiling tank containing sodium hydroxide solution to dissolve the aluminum. During this process, some of the aluminum reacts with the sodium hydroxide solution to produce sodium aluminate and hydrogen gas, reducing the concentration of the sodium hydroxide solution in the boiling tank. This affects the efficiency and purpose of cleaning the extrusion mold, requiring frequent replacement of the waste alkaline solution in the boiling tank, resulting in high sodium hydroxide consumption. Sodium aluminate can decompose under certain conditions with water to form crystalline aluminum hydroxide hydrate. The crystalline aluminum hydroxide hydrate combines and grows to form aluminum hydroxide crystals that precipitate in the liquid. Meanwhile, sodium hydroxide separates from the crystalline aluminum hydroxide hydrate to form a sodium hydroxide solution, resulting in a stratified separation between the sodium hydroxide solution and the aluminum hydroxide crystals.

[0003] The existing waste alkali solution recovery device for mold making has the following problems: 1. A dosing pump is required to pump the reagent in the dosing tank to the crystallization tank in a metered manner; 2. The wastewater separated by the centrifuge needs to be pumped to the equalization tank for adjustment before being pumped to the crystallization tank; 3. The crystallization tank lacks a solid-liquid separation mechanism, which causes a large number of solid particles to be discharged from the crystallization tank along with the sodium hydroxide solution, increasing the workload of the security filter and the number of times the security filter needs to be cleaned. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned problems in the existing technology and provide a waste alkali solution recovery system for mold making.

[0005] To achieve the above-mentioned technical objectives and effects, this utility model is implemented through the following technical solution:

[0006] A waste alkali solution recycling system for mold making includes multiple parallel mold making tanks, a waste alkali solution collection tank, a crystallization reaction tower, a crystal filter tank, a reuse alkali solution tank, a centrifuge, and a separation liquid tank. The outlet of each mold making tank is connected to the waste alkali solution collection tank via a manifold. The waste alkali solution collection tank is connected to the crystallization reaction tower via a waste alkali solution lift pipe equipped with a waste alkali solution lift pump. An overflow pipe inserted into the crystal filter tank is installed on one side of the top of the crystallization reaction tower. A guide pipe inserted into the reuse alkali solution tank is installed on the bottom of the crystal filter tank. A distribution pipe for sending reuse alkali solution into each mold making tank is installed on the bottom side of the reuse alkali solution tank. A mixed liquid delivery pipe is connected to the mixed liquid inlet of the centrifuge via a mixed liquid delivery pipe on one side of the bottom of the crystallization reaction tower. A separation liquid delivery pipe inserted into the separation liquid tank is installed on the side of the centrifuge. The separation liquid tank is connected to the crystallization reaction tower via a separation liquid lift pipe equipped with a separation liquid lift pump.

[0007] Each of the mold-making tanks is equipped with a gas collection hood at its top, and a floor-standing waste gas spray tower is installed on one side of each mold-making tank. The air inlet of the waste gas spray tower is connected to each gas collection hood through a gas collection pipe. A liquid receiving tank is provided at the bottom of the waste gas spray tower, and the liquid receiving tank is connected to a waste alkali liquid collection tank through a manifold. The liquid receiving tank is connected to the top of the waste gas spray tower through a spray pipe equipped with a spray pump. An exhaust pipe is installed at the top of the waste gas spray tower, and a fan for exhausting air is installed at the end of the exhaust pipe.

[0008] The waste alkali collection tank is equipped with a level sensor for monitoring the liquid level in the waste alkali collection tank.

[0009] The crystallization reaction tower includes a trumpet-shaped tower body, the bottom of which is closed, and a variable frequency motor installed at the top of the tower body. A stirring paddle extending into the middle of the tower body is installed on the motor shaft of the variable frequency motor. A circular recycled alkali collection tank is fixed to the inner side of the top of the tower body. The recycled alkali collection tank is connected to an overflow pipe, and a circular solid-liquid separation filter screen is installed on the recycled alkali collection tank.

[0010] The tower body is equipped with a water convection diversion grid in the middle. The water convection diversion grid includes a circular annular pipe, several diversion strips with a slightly curved cross-section, and multiple connecting rings. The top of the circular annular pipe is fixedly connected to a main inlet pipe for connecting to the end of the waste alkali liquid riser pipe. The top of the diversion strip is fixedly connected to the bottom of the circular annular pipe, and the concave side of the diversion strip faces the central axis of the circular annular pipe. The bottom of the circular annular pipe has water outlet holes that correspond one-to-one with the concave side of the diversion strip. The inner side of the connecting ring is fixedly connected to the convex side of the diversion strip.

[0011] A heater for heating the waste alkali solution is installed at one end of the waste alkali solution riser near the crystallization reaction tower.

[0012] The filter tank includes a cuboid tank and a rectangular filter membrane. The filter membrane is installed at an angle in the tank, dividing the interior of the tank into a filter residue area and a reuse alkali solution area. The bottom of the overflow pipe is inserted into the filter residue area. The reuse alkali solution area is connected to the liquid guide pipe, and the width of the reuse alkali solution area gradually increases from bottom to top.

[0013] The centrifuge is equipped with a water inlet pipe with a shut-off valve at its top, and the top of the water inlet pipe is connected to the tap water pipe in the factory.

[0014] The beneficial effects of this utility model are: the mold-making waste alkali recovery system designed based on the principle of sodium aluminate hydrolysis eliminates the need for a dosing device and an equalization tank, thus simplifying the system structure. By installing a solid-liquid separation filter in the crystallization reaction tower to intercept solid particles, the amount of sodium hydroxide crystal particles discharged into the crystal filter tank is reduced, thereby reducing the amount of sodium hydroxide crystal particles filtered out of the crystal filter tank and thus reducing the number of times the crystal filter tank needs to be cleaned. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0016] Figure 1 This is a schematic diagram of the process flow of the waste alkali liquid recovery system for mold boiling in this utility model.

[0017] Figure 2 This is a schematic diagram of the crystallization reaction tower in this utility model;

[0018] Explanation of the numbers in the diagram: 1. Molding tank; 2. Waste alkali collection tank; 3. Crystallization reaction tower; 301. Tower body; 302. Recycled alkali collection tank; 303. Solid-liquid separation filter screen; 4. Crystal filter tank; 401. Tank body; 402. Filter membrane; 403. Filter residue area; 404. Recycled alkali area; 5. Recycled alkali tank; 6. Centrifuge; 7. Separated liquid tank; 8. Gas collection hood; 9. Waste gas spray tower; 901. Liquid receiving tank; 10. Fan; 11. Manifold; 12. Waste alkali riser; 13. Heater; 14. Variable frequency motor. 14. Agitator 15. Water convection and diversion grid 16. Circular pipe 1601. Diversion strip 1602. Connecting ring 1603. Main water inlet pipe 1604. Overflow pipe 17. Liquid guide pipe 18. Liquid distribution pipe 19. Mixed liquid conveying pipe 20. Water receiving pipe 21. Separated liquid conveying pipe 22. Separated liquid lift pump 23. Separated liquid lift pipe 24. Gas collection pipe 25. Spray pump 26. Spray pipe 27. Exhaust pipe 28. Waste alkali liquid lift pump 29. Liquid level sensor 30. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 and Figure 2As shown, a waste alkali solution recycling system for mold making includes multiple parallel mold making tanks 1, waste alkali solution collection tanks 2, crystallization reaction towers 3, crystal filtration tanks 4, reuse alkali solution tanks 5, centrifuges 6, and separation liquid tanks 7. Each mold making tank 1 is equipped with a gas collection hood 8 at its top. A floor-mounted waste gas spray tower 9 is installed on one side of each mold making tank 1. The air inlet of the waste gas spray tower 9 is connected to each gas collection hood 8 through a gas collection pipe 25. A liquid receiving tank 901 is provided at the bottom of the waste gas spray tower 9. The liquid receiving tank 901 is connected to the top of the waste gas spray tower 9 through a spray pipe 27 equipped with a spray pump 26. An exhaust pipe 28 is installed at the top of the waste gas spray tower 9. A fan 10 for exhausting air is installed at the end of the exhaust pipe 28.

[0021] Each mold-making tank 1 has its outlet and receiving tank 901 connected to the waste alkali collection tank 2 via a manifold 11. The waste alkali collection tank 2 is connected to the crystallization reaction tower 3 via a waste alkali lift pipe 12 equipped with a waste alkali lift pump 29. A level sensor 30 is installed in the waste alkali collection tank 2 to monitor the liquid level. When the level sensor 30 detects that the liquid level in the waste alkali collection tank 2 is lower than the threshold, it feeds back to the controller, causing the controller to control the waste alkali lift pump to stop lifting the waste alkali. A heater 13 for heating the waste alkali is installed at the end of the waste alkali lift pipe 12 near the crystallization reaction tower 3.

[0022] An overflow pipe 17 is installed on one side of the top of the crystallization reaction tower 3 and inserted into the crystal filter tank 4. A liquid guide pipe 18 is installed at the bottom of the crystal filter tank 4 and inserted into the recycled alkali tank 5. A distribution pipe 19 is installed on the bottom side of the recycled alkali tank 5 to send the recycled alkali into each of the mold-making tanks 1.

[0023] The bottom side of the crystallization reaction tower 3 is connected to the mixed liquid inlet of the centrifuge 6 through the mixed liquid delivery pipe 20. The centrifuge 6 is equipped with a separation liquid delivery pipe 22 that is inserted into the separation liquid tank 7. The separation liquid tank 7 is connected to the crystallization reaction tower 3 through a separation liquid lift pipe 24 equipped with a separation liquid lift pump 23. In order to facilitate the cleaning of the centrifuge 6, a water inlet pipe 21 with a shut-off valve is installed at the top of the centrifuge 6. The top of the water inlet pipe 21 is connected to the tap water pipe in the factory.

[0024] The crystallization reaction tower 3 includes a trumpet-shaped tower body 301, the bottom of the tower body 301 is closed, and a variable frequency motor 14 is installed at the top of the tower body 301. A stirring paddle 15 extending into the middle of the tower body 301 is installed on the motor shaft of the variable frequency motor 14. A circular ring-shaped recycled alkali collection tank 302 is fixed to the inner side of the top of the tower body 301. The recycled alkali collection tank 302 is connected to the overflow pipe 17. A circular ring-shaped solid-liquid separation filter screen 303 is installed on the recycled alkali collection tank 302.

[0025] To ensure that the heated waste alkali solution is evenly added to the crystallization reaction tower 3 and to promote uniform mixing and heat exchange between the heated waste alkali solution and the solution in the crystallization reaction tower, a water convection diversion grid 16 is installed in the middle of the tower body 301. The water convection diversion grid 16 includes a circular annular pipe 1601, several diversion strips 1602 with a slightly curved cross section, and multiple connecting rings 1603. The top of the circular annular pipe 1601 is fixedly connected to a main water inlet pipe 1604 for connecting to the end of the waste alkali solution riser pipe 12. The top of the diversion strips 1602 is fixedly connected to the bottom of the circular annular pipe 1601, and the concave side of the diversion strips 1601 faces the central axis of the circular annular pipe 1601. The bottom of the circular annular pipe 1601 has water outlet holes that correspond one-to-one with the concave side of the diversion strips 1602. The inner side of the connecting rings 1603 is fixedly connected to the convex side of the diversion strips 1602.

[0026] The filter tank 4 includes a cuboid tank body 401 and a rectangular filter membrane 402. The filter membrane 402 is installed at an angle in the tank body 401, dividing the interior of the tank body 401 into a filter residue area 403 and a reuse alkali solution area 404. The bottom of the overflow pipe 17 is inserted into the filter residue area 403. The reuse alkali solution area 404 is connected to the liquid guide pipe 18, and the width of the reuse alkali solution area 404 gradually increases from bottom to top.

[0027] When the crystallization reaction tower 3 is used for the first time, it is filled with alumina complex as a catalytic seed crystal to promote the hydrolysis reaction of waste alkali. When the crystallization reaction tower 3 is running normally, it will generate an effective substance that promotes the hydrolysis reaction of waste alkali. Therefore, no additional addition is required in the future, unless the crystallization reaction tower 3 is thoroughly cleaned and then filled with alumina complex again.

[0028] Working principle: The waste alkali solution generated in the mold-making tank is discharged into the waste alkali solution collection tank through the manifold. The waste alkali solution is then pumped to the waste alkali solution riser pipe using a waste alkali solution lifter pump. After being heated by a heater, it flows into the crystallization reaction tower. A variable frequency motor drives the stirring paddle to rotate and stir the waste alkali solution. The sodium aluminate in the waste alkali solution decomposes to form crystalline aluminum hydroxide. The crystalline aluminum hydroxide combines with each other to grow into aluminum hydroxide crystal particles, which precipitate to the bottom of the crystallization reaction tower. The mixed solution containing aluminum hydroxide crystal particles is discharged into a centrifuge for separation to form aluminum hydroxide crystal particles containing a small amount of liquid and a separation liquid. The aluminum hydroxide crystal particles are bagged and sold. The separation liquid is discharged into the separation liquid tank and then pumped back into the crystallization reaction tower using a separation liquid lifter pump. The sodium hydroxide rises to the top of the crystallization reaction tower and flows out into the crystal filter tank. After filtration, it is discharged into the recycled alkali solution collection tank for later use. When it is necessary to replace the sodium hydroxide solution in the mold-making tank, the alkali solution in the recycled alkali solution collection tank is put back into the mold-making tank.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A system for recovering waste alkali solution from mold boiling, characterized in that: The system includes multiple parallel-connected molding tanks, a waste alkali collection tank, a crystallization reaction tower, a crystal filter tank, a recycled alkali tank, a centrifuge, and a separation liquid tank. The outlet of each molding tank is connected to the waste alkali collection tank via a manifold. The waste alkali collection tank is connected to the crystallization reaction tower via a waste alkali lift pipe equipped with a waste alkali lift pump. An overflow pipe inserted into the crystal filter tank is installed on one side of the top of the crystallization reaction tower. A guide pipe inserted into the recycled alkali tank is installed on the bottom of the crystal filter tank. A distribution pipe for distributing recycled alkali into each molding tank is installed on the bottom side of the recycled alkali tank. One side of the bottom of the crystallization reaction tower is connected to the mixed liquid inlet of the centrifuge via a mixed liquid delivery pipe. A separation liquid delivery pipe inserted into the separation liquid tank is installed on the side of the centrifuge. The separation liquid tank is connected to the crystallization reaction tower via a separation liquid lift pipe equipped with a separation liquid lift pump.

2. The mold-making waste alkali recovery system according to claim 1, characterized in that: Each of the mold-making tanks is equipped with a gas collection hood at its top. A floor-standing waste gas spray tower is installed on one side of each mold-making tank. The air inlet of the waste gas spray tower is connected to each gas collection hood through a gas collection pipe. A liquid receiving tank is provided at the bottom of the waste gas spray tower. The liquid receiving tank is connected to a waste alkali liquid collection tank through a manifold. The liquid receiving tank is connected to the top of the waste gas spray tower through a spray pipe equipped with a spray pump. An exhaust pipe is installed at the top of the waste gas spray tower. A fan for exhausting air is installed at the end of the exhaust pipe.

3. The mold-making waste alkali recovery system according to claim 1, characterized in that: The waste alkali collection tank is equipped with a level sensor for monitoring the liquid level in the tank.

4. The mold-making waste alkali recovery system according to claim 1, characterized in that: The crystallization reaction tower includes a trumpet-shaped tower body, the bottom of which is closed, and a variable frequency motor installed at the top of the tower body. A stirring paddle extending into the middle of the tower body is installed on the motor shaft of the variable frequency motor. A circular reclaimed alkali collection tank is fixed to the inner side of the top of the tower body. The reclaimed alkali collection tank is connected to an overflow pipe, and a circular solid-liquid separation filter screen is installed on the reclaimed alkali collection tank.

5. The mold-making waste alkali recovery system according to claim 4, characterized in that: A water convection diversion grid is installed in the middle of the tower body. The water convection diversion grid includes a circular annular pipe, several diversion bars with a slightly curved cross-section, and multiple connecting rings. The top of the circular annular pipe is fixedly connected to a main inlet pipe for connecting to the end of the waste alkali liquid riser pipe. The top of the diversion bar is fixedly connected to the bottom of the circular annular pipe, and the concave side of the diversion bar faces the central axis of the circular annular pipe. The bottom of the circular annular pipe has water outlet holes that correspond one-to-one with the concave side of the diversion bar. The inner side of the connecting ring is fixedly connected to the convex side of the diversion bar.

6. The mold-making waste alkali recovery system according to claim 1, characterized in that: A heater for heating the waste alkali solution is installed at one end of the waste alkali solution riser near the crystallization reaction tower.

7. The mold-making waste alkali recovery system according to claim 1, characterized in that: The filter tank includes a cuboid tank and a rectangular filter membrane. The filter membrane is installed at an angle in the tank, dividing the interior of the tank into a filter residue area and a reuse alkali solution area. The bottom of the overflow pipe is inserted into the filter residue area. The reuse alkali solution area is connected to the liquid guide pipe, and the width of the reuse alkali solution area gradually increases from bottom to top.

8. The mold-making waste alkali recovery system according to claim 1, characterized in that: The centrifuge is equipped with a water inlet pipe with a shut-off valve at its top, and the top of the water inlet pipe is connected to the tap water pipe in the factory.

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