Evaporation system for cleaning waste liquid of etching liquid storage tank

Abstract

The utility model discloses an etching liquid storage tank cleaning waste liquid evaporation system which comprises a feeding pump, a preheater, a first-effect separator, a first-effect heater, a second-effect separator, a second-effect heater, a third-effect separator, a third-effect heater, a thickener and a centrifugal machine which are sequentially connected. Comprising a falling film heater, an evaporation chamber and a steam compressor, and has the beneficial effects that the evaporation rate of the film evaporator is higher than that of other evaporators, and waste liquid can be rapidly concentrated through the falling film heater; steam in the first-effect separator is compressed through the steam compressor and then returns to the first-effect heater, sufficient heat of the rear section is effectively guaranteed, and the evaporation effect is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical waste liquid treatment, in particular to an evaporation system for cleaning waste liquid of an etching solution storage tank. Background Art

[0002] An etching solution is a special solution composed of a chemical corrosive agent and other additives, and is widely used in fields such as printed circuit boards, manufacturing of micro parts, and carving of artworks. Its main function is to corrode the copper material on the printed circuit board that is not covered by the protective layer to form circuit patterns and contact surfaces. Generally, etching solutions can be divided into acidic etching solutions, alkaline etching solutions, and neutral etching solutions according to their acidity and alkalinity. In the processing and production of etching solutions, raw materials are added to a stirring device, and the various raw material components are mixed evenly through stirring, and then filled into the temporary storage solvent tanks of each manufacturer for sale. When the solvent tank needs to be refilled with new solvent after use, the inside of the solvent tank needs to be repeatedly rinsed. If not rinsed, the residual etching solution on the tank wall will react with the newly filled etching solution, causing the etching solution to fail.

[0003] Generally, the waste liquid generated during the cleaning process needs to be pretreated by adding relevant acid-base solvents for neutralization to obtain a low-concentration salt solution. Subsequently, the solvent in the waste liquid can be evaporated and concentrated by means of evaporation crystallization. On the one hand, the condensed liquid can be reused, and at the same time, the crystals obtained by evaporation also have certain commercial sales value through subsequent processing. In this way, a production method with nearly zero pollutant emissions is more environmentally friendly. However, traditional evaporation crystallization systems are mostly applied to high-concentration wastewater. If the traditional system is directly applied to the treatment of cleaning waste liquid, the efficiency is relatively low because the solute concentration in the cleaning waste liquid is low, resulting in a long evaporation time required to form concentration and reach the crystallization state. Therefore, an evaporation system with low energy consumption and faster concentration is needed. Content of the Utility Model

[0004] In order to solve the above technical problems, the utility model provides an evaporation system for cleaning waste liquid of an etching solution storage tank.

[0005] The specific technical solution is as follows:

[0006] Etching solution storage tank cleaning waste liquid evaporation system, including a feed pump, a preheater, a first-effect separator, a first-effect heater, a second-effect separator, a second-effect heater, a third-effect separator, a third-effect heater, a thickener and a centrifuge connected in sequence. There are circulating pipelines on the first-effect separator and the first-effect heater, and a first-effect forced circulation pump is arranged at the lower part of the pipeline. There are circulating pipelines on the second-effect separator and the second-effect heater, and a second-effect forced circulation pump is arranged at the lower part of the pipeline. There are circulating pipelines on the third-effect separator and the third-effect heater, and a third-effect forced circulation pump is arranged at the lower part of the pipeline. The circulating pipeline on the first-effect separator and the first-effect heater and the circulating pipeline on the second-effect separator and the second-effect heater are connected to each other and are provided with a first feeding pump. The circulating pipeline on the second-effect separator and the second-effect heater and the circulating pipeline on the third-effect separator and the third-effect heater are connected to each other and are provided with a second feeding pump. The circulating pipeline on the third-effect separator and the third-effect heater is connected to the thickener, and a third feeding pump is arranged on the connecting pipeline. A steam pipeline is connected between the upper part of the third-effect separator and the second-effect heater, and a steam pipeline is connected between the upper part of the second-effect separator and the first-effect heater.

[0007] A pre-evaporation system is also connected between the preheater and the first-effect separator, including a falling film heater, an evaporation chamber and a steam compressor. The falling film heater is communicated with the lower part of the evaporation chamber, and a steam pipeline is communicated between the upper part of the falling film heater and the evaporation chamber, and the steam compressor is arranged on this steam pipeline. The falling film heater and the lower part of the evaporation chamber are connected to the first-effect separator through a pipeline, and a fourth feeding pump is connected to this pipeline.

[0008] The steam pipeline at the top of the first-effect separator is connected to the air inlet of the steam compressor, and the air outlet of the steam compressor is also connected to the air inlet of the first-effect heater.

[0009] Condensate pipelines are arranged at the lower parts of the first-effect heater, the second-effect heater and the third-effect heater, and the condensate pipelines are connected to the liquid inlet of the preheater.

[0010] Non-condensable gas discharge pipes are arranged at the upper parts of the first-effect heater, the second-effect heater and the third-effect heater.

[0011] Online refractometers are arranged on the circulating pipelines of the first-effect separator and the first-effect heater, the second-effect separator and the second-effect heater, and the third-effect separator and the third-effect heater.

[0012] A condenser is connected to the shell-side discharge port of the preheater, and a condensate water tank is connected to the outlet of the condenser.

[0013] The liquid discharge pipelines of the thickener and the centrifuge are both connected to the mother liquid tank, and the mother liquid tank is connected to the circulating pipeline of the third-effect separator and the third-effect heater.

[0014] Compared with the prior art, the technical solution proposed by the present utility model has the following advantages: The evaporation rate of the thin-film evaporator is higher than that of other evaporators. The waste liquid can be quickly concentrated by passing through the falling-film heater first, and then through the triple-effect evaporation system to achieve further evaporation. During the process, the solution is continuously concentrated to ensure that solid-liquid separation can be carried out subsequently. At the same time, only steam is introduced into the triple-effect heater to ensure the effective utilization of heat sources. Meanwhile, the steam in the first-effect separator is compressed by a steam compressor and then returned to the first-effect heater, effectively ensuring sufficient heat in the latter stage and guaranteeing the evaporation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings in the following descriptions are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic structural diagram of the present utility model; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the utility model. The described embodiments are only some embodiments of the utility model, rather than all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the utility model.

[0018] In the related prior art, traditional evaporation crystallization systems are mostly applied to high-concentration wastewater. If the traditional system is directly applied to the treatment of cleaning waste liquid, the efficiency is relatively low because the solute concentration in the cleaning waste liquid is relatively low, resulting in a long evaporation time required to form a concentrate to reach the crystallization state. Therefore, an evaporation system with low energy consumption and faster concentration is needed.

[0019] To solve the problems existing in the related prior art, the present utility model proposes an evaporation system for cleaning waste liquid in an etching solution storage tank. The principle and structure of the present utility model will be described in detail below with reference to the drawings and embodiments. Embodiment 1

[0020] Please refer to Figure 1, the present utility model provides an evaporation system for cleaning waste liquid of an etching solution storage tank, which includes a feed pump 1, a preheater 2, a first-effect separator 3, a first-effect heater 4, a second-effect separator 5, a second-effect heater 6, a third-effect separator 7, a third-effect heater 8, a thickener 9 and a centrifuge 10 connected in sequence. There are circulation pipelines on the first-effect separator 3 and the first-effect heater 4, and a first-effect forced circulation pump 11a is provided at the lower part of the pipeline. There are circulation pipelines on the second-effect separator 5 and the second-effect heater 6, and a second-effect forced circulation pump 11b is provided at the lower part of the pipeline. There are circulation pipelines on the third-effect separator 7 and the third-effect heater 8, and a third-effect forced circulation pump 11c is provided at the lower part of the pipeline. The circulation pipelines on the first-effect separator 3 and the first-effect heater 4 and the circulation pipelines on the second-effect separator 5 and the second-effect heater 6 are connected to each other and a first feeding pump 12a is provided. The circulation pipelines on the second-effect separator 5 and the second-effect heater 6 and the circulation pipelines on the third-effect separator 7 and the third-effect heater 8 are connected to each other and a second feeding pump 12b is provided. The circulation pipeline on the third-effect separator 7 and the third-effect heater 8 is connected to the thickener 9, and a third feeding pump 12c is provided on the connecting pipeline. A steam pipeline is connected between the upper part of the third-effect separator 7 and the second-effect heater 6, and a steam pipeline is connected between the upper part of the second-effect separator 5 and the first-effect heater 4.

[0021] During use, the raw material is pumped into the first-effect separator 3 by the feed pump 1, and is heated to a high temperature by the preheater 2 during the process. Then, under the action of the first forced circulation pump 11a, the raw material performs forced circulation in the first-effect circulation pipeline formed by the first-effect separator 3 and the first-effect heater 4. During the circulation process, the raw material is continuously heated by the first-effect heater 4. After being heated, the raw material enters the first-effect separator 3 where gas-liquid two-phase separation occurs, and the steam is discharged from the upper pipeline out of the circulation system. Therefore, the concentration of the raw material continuously increases during the circulation process. After circulating for a period of time, it is pumped into the second-effect separator 5 by the bottom first feeding pump 12a. In the second-effect separator 5, it circulates in the second-effect separator 5 and the second-effect heater 6 by the second-effect forced circulation pump 11b to complete further concentration. The principle is the same as that of the first-effect circulation concentration process. After circulating in the second-effect separator 5 and the second-effect heater 6 for a period of time, it enters the third-effect separator 7 through the second feeding pump 12b to complete the third evaporation. At the same time, under the action of the third-effect forced circulation pump 11c, heating and the third evaporation are completed in the circulation pipeline formed by the third-effect separator 7 and the third-effect heater 8. After three evaporations, the raw material is pumped into the thickener by the third feeding pump 12c, and then enters the centrifuge to filter the crystals precipitated inside after concentration, obtaining the solute part in the waste liquid.

[0022] During the entire heating process, external steam is only introduced into the triple-effect heater 8. The steam enters the tube side of the triple-effect heater 8 to exchange heat with the raw material, forming condensate that is discharged from the bottom of the triple-effect heater 8. The steam discharged from the upper part of the triple-effect separator 7 is connected to the tube side of the double-effect heater 6 through a pipeline to provide heat for the double-effect evaporation system. Similarly, the steam formed in the double-effect separator 5 is introduced into the tube side of the single-effect heater 4 from the upper pipeline to provide heat for the single-effect cycle. The heat is fully utilized in the whole process, which is more energy-saving.

[0023] Please continue to refer to Figure 1 , and a pre-evaporation system is also connected between the preheater 2 and the single-effect separator 3, including a falling-film heater 13, an evaporation chamber 14, and a steam compressor 15. The falling-film heater 13 is connected to the lower part of the evaporation chamber 14. A steam pipeline is connected between the upper parts of the falling-film heater 13 and the evaporation chamber 14, and a steam compressor 15 is provided on this steam pipeline. The lower parts of the falling-film heater 13 and the evaporation chamber 14 are connected to the single-effect separator 3 through a pipeline, and a fourth feed pump 12d is connected to this pipeline. The steam pipeline at the top of the single-effect separator 3 is connected to the air inlet of the steam compressor 15, and the outlet of the steam compressor 15 is also connected to the air inlet of the single-effect heater 4.

[0024] The raw material is first heated to the evaporation temperature by the preheater 2, and then enters the falling-film heater 13. The raw material is evaporated and heated by the falling-film heater 13, and then the gas-liquid two-phase enters the evaporation chamber 14 together through the bottom pipeline. The gas-liquid two-phase separation is completed in the evaporation chamber 14. The liquid phase is pumped into the single-effect separator 3 by the fourth feed pump 12d, while the gas phase is introduced into the steam compressor 15 through the upper pipeline of the evaporation chamber 14 for repeated heating, and then introduced into the shell side of the falling-film heater 13 to heat the raw material that subsequently enters the tube side of the falling-film heater 13. This is to prevent insufficient heat in the single-effect heater 4. The steam discharged from the top of the single-effect separator 3 is also compressed by the steam compressor 15 and then sent to the shell side of the single-effect heater 4 to ensure sufficient heat. Compared with the forced-circulation evaporation system, the evaporation efficiency of falling-film evaporation is relatively high. If only the forced-circulation evaporation system is used, it will take a longer cycle to obtain the raw material with a predetermined concentration. Pre-evaporation through falling-film evaporation can achieve rapid concentration improvement, and then enter the triple-effect evaporation system, which not only ensures efficiency but also improves the concentration effect. The steam compressor 15 is used to simultaneously supply heat sources to the shell sides of the single-effect heater and the falling-film heater, ensuring sufficient heat during the evaporation process.

[0025] Condensate pipelines 16 are provided at the lower parts of the single-effect heater 4, the double-effect heater 6, and the triple-effect heater 8. The condensate pipelines 16 are connected to the liquid inlet of the preheater 2. The gas phase in the single-effect heater 4, the double-effect heater 6, and the triple-effect heater 8 condenses to form a liquid phase. When it still has relatively high heat, this part of the condensate is introduced into the shell side of the preheater 2 to preheat the raw material, so that the energy can be fully utilized.

[0026] A non-condensable gas discharge pipe 17 is provided at the upper part of each of the first-effect heater 4, the second-effect heater 6, and the third-effect heater 8. The presence of non-condensable gas in the steam will significantly reduce the steam condensation heat transfer coefficient. Therefore, the non-condensable gas is discharged in time through the non-condensable gas discharge pipe 17 to ensure the heat transfer effect.

[0027] Online refractometers 18 are provided on the circulation pipelines of the first-effect separator 3 and the first-effect heater 4, the circulation pipelines of the second-effect separator 5 and the second-effect heater 6, and the circulation pipelines of the third-effect separator 7 and the third-effect heater 8. The online refractometers 18 are used to monitor the raw material concentration in each circulation system in real time. When the predetermined concentration is reached, it enters the next circulation system, which improves the working efficiency on the one hand and prevents crystal blockage caused by too high concentration in the corresponding circulation system on the other hand.

[0028] The outlet of the shell side of the preheater 2 is connected to a condenser 19, the outlet of the condenser 19 is connected to a condensate tank 20, the liquid outlet pipelines of the thickener 9 and the centrifuge 10 are both connected to a mother liquor tank 21, and the mother liquor tank 21 is connected to the circulation pipeline of the third-effect separator 7 and the third-effect heater 8.

[0029] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An evaporation system for cleaning waste liquid in an etching solution storage tank, characterized in that: It includes a feed pump (1), a preheater (2), a first-effect separator (3), a first-effect heater (4), a second-effect separator (5), a second-effect heater (6), a third-effect separator (7), a third-effect heater (8), a thickener (9) and a centrifuge (10) connected in sequence. A circulation pipeline is provided on the first-effect separator (3) and the first-effect heater (4), and a first-effect forced circulation pump (11a) is provided at the lower part of the pipeline. A circulation pipeline is provided on the second-effect separator (5) and the second-effect heater (6), and a second-effect forced circulation pump (11b) is provided at the lower part of the pipeline. A circulation pipeline is provided on the third-effect separator (7) and the third-effect heater (8), and a third-effect forced circulation pump (11c) is provided at the lower part of the pipeline. The circulation pipeline on the first-effect separator (3) and the first-effect heater (4) and the circulation pipeline on the second-effect separator (5) and the second-effect heater (6) are connected to each other and are provided with a first feed pump (12a). The circulation pipeline on the second-effect separator (5) and the second-effect heater (6) and the circulation pipeline on the third-effect separator (7) and the third-effect heater (8) are connected to each other and are provided with a second feed pump (12b). The circulation pipeline on the third-effect separator (7) and the third-effect heater (8) is connected to the thickener (9), and a third feed pump (12c) is provided on the connecting pipeline. The upper part of the third-effect separator (7) is connected to the second-effect heater (6) by a steam pipeline, and the upper part of the second-effect separator (5) is connected to the first-effect heater (4) by a steam pipeline.

2. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, wherein: A pre-evaporation system is also connected between the preheater (2) and the first-effect separator (3), including a falling-film heater (13), an evaporation chamber (14) and a steam compressor (15). The falling-film heater (13) is communicated with the lower part of the evaporation chamber (14). A steam pipeline is communicated between the upper parts of the falling-film heater (13) and the evaporation chamber (14), and the steam compressor (15) is provided on this steam pipeline. The lower parts of the falling-film heater (13) and the evaporation chamber (14) are connected to the first-effect separator (3) through a pipeline, and a fourth feed pump (12d) is connected to this pipeline.

3. The etching solution storage tank cleaning waste liquid evaporation system according to claim 2, characterized in that: The steam pipeline at the top of the first-effect separator (3) is connected to the air inlet of the steam compressor (15), and the air outlet of the steam compressor (15) is also connected to the air inlet of the first-effect heater (4).

4. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, wherein: Condensate pipelines (16) are provided at the lower parts of the first-effect heater (4), the second-effect heater (6) and the third-effect heater (8), and the condensate pipelines (16) are connected to the liquid inlet of the preheater (2).

5. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, wherein: Non-condensable gas discharge pipes (17) are provided at the upper parts of the first-effect heater (4), the second-effect heater (6) and the third-effect heater (8).

6. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, wherein: Online refractometers (18) are provided on the circulation pipelines of the first-effect separator (3) and the first-effect heater (4), the circulation pipelines of the second-effect separator (5) and the second-effect heater (6), and the circulation pipelines of the third-effect separator (7) and the third-effect heater (8).

7. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, characterized in that: The outlet of the shell side of the preheater (2) is connected to a condenser (19), and the outlet of the condenser (19) is connected to a condensate water tank (20).

8. The etching solution storage tank cleaning waste liquid evaporation system according to claim 1, characterized in that: The liquid discharge pipelines of the thickener (9) and the centrifuge (10) are both connected to the mother liquor tank (21), and the mother liquor tank (21) is connected to the circulating pipeline of the triple-effect separator (7) and the triple-effect heater (8).

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