Automatic control system and method suitable for large-scale MQ generated waste liquid treatment

Abstract

The invention discloses an automatic control system and method suitable for large-scale MQ generated waste liquid treatment, and belongs to the technical field of fluorine chemical industry, the automatic control system comprises a wastewater buffer tank, a mixer, a pH online monitor, a neutralization washing storage tank, a rectifying tower, a filter, a molecular sieve adsorption tower, a triple effect evaporator and a DCS controller; the mixer is connected with a sodium hydroxide aqueous solution feeding unit; a first temperature control unit and a reflux control unit are arranged on the rectifying tower, an inlet and outlet flow control unit is arranged on the molecular sieve adsorption tower, and a second temperature control unit is arranged on the triple-effect evaporator. Continuous automatic control conditions are provided, the labor cost is reduced, and meanwhile, the ethanol recovery purity is improved to achieve the complete raw material recycling conditions; a sodium chloride aqueous solution produced after reaction and neutralization is treated to reduce organic components and impurities, so that a sodium chloride by-product with relatively good quality can be obtained, and the beneficial effects of effectively utilizing energy and reducing COD (Chemical Oxygen Demand) discharged from wastewater are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of MQ production, and in particular to an automated control system and method suitable for large-scale MQ production waste liquid treatment. Background Art

[0002] Silicone resin is a thermosetting polysiloxane polymer with a highly cross-linked structure, which has the dual characteristics of organic resin and inorganic material, unique physical and chemical properties, good electrical insulation properties, heat resistance and waterproof effect. When the silicate method is used to produce MQ type silicone resin, a large amount of acidic waste liquid will be produced as a byproduct, and these waste liquids are usually entrusted to qualified units for treatment. However, the acidic waste liquid contains a large amount of ethanol, a small amount of water, hydrochloric acid, xylene and some silicone resins with low cross-linked structures, etc., which cannot be fully utilized. Patent CN109705355A discloses a preparation process of a hydrophilic MQ silicone resin, and the raw materials include tetraethoxysilane, unsaturated polyether or methyl acrylate, hexamethyldisiloxane, trimethoxysilane, acid catalyst, chloroplatinic acid catalyst and dicyclohexyl phthalate, and the waste liquid is not reused in the preparation process. Therefore, in order to reduce costs, pollution and waste of resources, it is necessary to develop a method that can turn waste into treasure for acidic waste liquid and repeatedly utilize acidic waste liquid.

[0003] A Chinese patent with publication number CN113248711A and publication date 2021.08.13 discloses a method for reusing acidic waste liquid in the production process of silicone resin, comprising the following steps: S1, negative pressure distillation of MQ acidic waste liquid, the MQ acidic waste liquid produced as a by-product in the process of preparing MQ type silicone resin by the silicate method is pumped into a reactor, heated to 60°C to 70°C, and distilled under a negative pressure of 0.01 to 0.05Mpa, and 10 to 20% of the total liquid mass of the MQ acidic waste liquid is extracted. The remaining liquid in the reactor is cooled to 40°C to 50°C by a condenser to obtain the remaining liquid Y; S2, negative pressure distillation of MQ acidic waste liquid, the by-product MQ acidic waste liquid is pumped into a reactor, the temperature is raised to 60°C to 70°C, and the distillation is performed under a negative pressure of 0.01 to 0.05Mpa, and the distillate X is extracted. The remaining liquid in the reactor is cooled to 40°C to 50°C by a condenser to obtain the remaining liquid Y; 2. Detection of distillate X: Perform gas chromatography analysis on distillate X. When distillate X is an ethanol solution with a volume percentage of 88-95%, perform the next step of detecting the remaining liquid Y. If distillate X is not an ethanol solution with a volume percentage of 88-95%, repeat the distillation until distillate X is an ethanol solution with a volume percentage of 88-95%. S3. Detection of the composition of the remaining liquid Y: Use titration to test the hydrochloric acid concentration of the remaining liquid Y; Use an alcohol concentration meter to detect the alcohol content; Use baking soda to neutralize and filter the remaining liquid Y, and then use gas chromatography to detect the xylene content; Take the remaining liquid Y after neutralization and filtration with baking soda 0.8~1.2g, place it in a 150℃ blast oven for drying until the weight of the remaining liquid Y no longer decreases, and detect the solid content of the remaining liquid after drying; use a moisture content meter to detect the moisture content in the remaining liquid Y; S4, recycling of the remaining liquid Y, put the remaining liquid Y into a reactor, add concentrated hydrochloric acid, anhydrous alcohol, hexamethyldisiloxane and ethyl orthosilicate to the reactor, so that the content of concentrated hydrochloric acid and anhydrous alcohol in the mixed liquid is the same as that used in the preparation of MQ type silicone resin by the silicate method in S1, and then stir at room temperature for 1~2h; then add deionized water dropwise to the reactor for 3.5~4.5h, and the deionized water added dropwise and the moisture in the remaining liquid Y are reduced. The sum of the contents is the same as the amount of deionized water used in preparing MQ type silicone resin by silicate method in S1; the temperature is then raised to 60℃~70℃ for polymerization reaction, the polymerization reaction time is 4h~5h, and then xylene is added for extraction and stratification when the temperature is lowered to 40℃~50℃, and the sum of the xylene contents in the added xylene and the remaining liquid Y is the same as the amount of xylene used in preparing MQ type silicone resin by silicate method in S1; after stratification, the oil phase is washed and filtered, and the temperature is raised to 130℃~150℃, and the solvent is distilled off under negative pressure of 0.01~0.05Mpa, and the remaining solid is crushed to 200~300 meshes to obtain white powder MQ type silicone resin. This method has the disadvantages of low automation and high labor intensity. Summary of the invention

[0004] The present invention aims to solve the problems existing in the prior art, and provides an automated control system and method suitable for large-scale MQ generation waste liquid treatment, which has continuous automated control conditions, reduces labor costs, and improves the purity of ethanol recovery to achieve complete raw material reuse conditions. The sodium chloride aqueous solution produced after reaction and neutralization is treated to reduce organic components and impurities to obtain sodium chloride byproducts with better quality, effectively realizing energy utilization and reducing the beneficial effects of COD discharged from wastewater.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An automated control system suitable for large-scale MQ generation waste liquid treatment comprises a wastewater buffer tank, a mixer, a pH online monitor, a neutralization water washing storage tank, a distillation tower, a filter, a molecular sieve adsorption tower and a triple-effect evaporator which are connected in sequence; the mixer is connected to a sodium hydroxide aqueous solution feeding unit, the pH online monitor monitors the pH value after the mixer in real time, and transmits the real-time monitored pH value to a DCS controller; the distillation tower is provided with a first temperature control unit and a reflux control unit, the first temperature control unit is used to control the temperature in the distillation tower, and the reflux control unit is used to control the reflux ratio of the distillation tower; the molecular sieve adsorption tower is provided with an inlet and outlet flow control unit, the inlet and outlet flow control unit is used to control the flow at the inlet and outlet of the molecular sieve adsorption tower, the triple-effect evaporator is provided with a second temperature control unit, the second temperature control unit is used to control the temperature in the triple-effect evaporator; the first temperature control unit, the inlet and outlet flow control unit and the second temperature control unit are connected to a DCS controller.

[0007] Preferably, the sodium hydroxide aqueous solution feeding unit comprises a sodium hydroxide aqueous solution feeding pipe and a sodium hydroxide aqueous solution feeding valve arranged on the sodium hydroxide aqueous solution feeding pipe, and the sodium hydroxide aqueous solution feeding valve is connected to a DCS controller.

[0008] Preferably, the first temperature control unit includes a first temperature sensor, a second temperature sensor and a first steam feed assembly, the first temperature sensor is arranged on the bottom of the distillation tower, the second temperature sensor is arranged on the top of the distillation tower, the first steam feed assembly is connected to the reboiler on the distillation tower, the first steam feed assembly includes a first steam feed pipe and a first steam feed valve arranged on the first steam feed pipe, and the first temperature sensor, the second temperature sensor and the first steam feed valve are connected to the DCS controller.

[0009] Preferably, the reflux control unit includes a condensate outlet pipe connected to the cooler, the condensate outlet pipe is connected to the reflux pipe and the ethanol circulation pipe, the reflux pipe and the ethanol circulation pipe are respectively provided with a first reflux valve and a second reflux valve, the first reflux valve and the second reflux valve are connected to the DCS control.

[0010] Preferably, the inlet and outlet flow control unit includes an adsorption tower feed pipe and an adsorption tower discharge pipe arranged on the molecular sieve adsorption tower, and the adsorption tower feed pipe and the adsorption tower discharge pipe are respectively provided with an adsorption tower feed valve and an adsorption tower discharge valve, and the adsorption tower feed valve and the adsorption tower discharge valve are connected to the DCS controller.

[0011] Preferably, the second temperature control unit comprises a third temperature sensor and a power component, the third temperature sensor is arranged on the triple-effect evaporator, and the power component is connected to the electric heater on the triple-effect evaporator of the distillation tower.

[0012] Preferably, the wastewater buffer tank is connected to the reaction liquid stratification tank via a connecting pipe.

[0013] An automated control method for large-scale MQ production wastewater treatment, comprising the following steps:

[0014] Step 1: The aqueous phase waste liquid and the sodium hydroxide aqueous solution generated by the water glass method for preparing MQ flow into the mixer through the wastewater buffer tank and the sodium hydroxide aqueous solution feeding unit respectively, and the DCS controller controls the feed flow rate of the sodium hydroxide aqueous solution through the sodium hydroxide aqueous solution feeding unit according to the real-time pH value detected by the pH online monitor so that the solution after passing through the mixer is neutral or slightly alkaline;

[0015] Step 2: The solution after the mixer flows through the neutralization water washing storage tank and then flows into the distillation tower for distillation. The DCS controller separates ethanol and tower bottom produced liquid through the first temperature control unit, the first pressure control unit and the reflux control unit. The ethanol flows back to the reactor for reuse, and the tower bottom produced liquid flows into the molecular sieve adsorption tower;

[0016] Step 3: The produced liquid from the tower bottom is filtered through a filter to remove mechanical impurities and then enters the molecular sieve adsorption tower for adsorption. The DCS controller controls the flow of the molecular sieve adsorption tower inlet and outlet through the inlet and outlet flow control unit to remove impurities and trace MQ resin to obtain a high-salt wastewater impurity-removing liquid with reduced organic matter content, and the impurity-removing liquid flows into the triple-effect evaporator;

[0017] Step 4: The impurity removal liquid is evaporated and crystallized in a triple-effect evaporator, and the DCS controller obtains industrial salt and treatable wastewater through the second temperature control unit.

[0018] Preferably, in step 1, the flow rate of the aqueous phase waste liquid generated by the water glass method for preparing MQ is 2000-5000 Kg / h; the pH value is controlled at 7-9; and the concentration of the sodium hydroxide aqueous solution is 30-33 wt%.

[0019] Preferably, in step 2, the top temperature of the distillation tower is controlled at 80-90°C by the first temperature control unit, the bottom temperature of the distillation tower is controlled at 100-120°C by the first temperature control unit, and the reflux ratio of the distillation tower is controlled at 5-10:1 by the reflux control unit.

[0020] Preferably, in step three, the flow rates at the inlet and outlet of the molecular sieve adsorption tower are controlled to be 1000-2000 kg / h by an inlet and outlet flow control unit.

[0021] Preferably, in step 4, the temperature of the three-effect evaporator is controlled at 110-120° C. by a second temperature control unit.

[0022] The beneficial effects of this technical solution are as follows:

[0023] 1. The present invention provides an automated control system suitable for large-scale MQ production waste liquid treatment, which has continuous automated control conditions, reduces labor costs, and at the same time improves the purity of ethanol recovery to achieve complete raw material reuse conditions. The sodium chloride aqueous solution produced after reaction and neutralization is treated to reduce organic components and impurities to obtain sodium chloride by-products with better quality, effectively realizing energy utilization and reducing the beneficial effects of COD discharged from wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a process flow chart of the present invention;

[0025] Figure 2 is a process flow chart of an embodiment of the present invention;

[0026] Wherein: 1. Wastewater buffer tank; 2. Mixer; 3. pH online monitor; 4. Neutralization water washing tank; 5. Distillation tower; 6. Filter; 7. Molecular sieve adsorption tower; 8. Triple effect evaporator; 9. Sodium hydroxide aqueous solution feeding unit; 91. Sodium hydroxide aqueous solution feeding pipe; 92. Sodium hydroxide aqueous solution feeding valve; 10. First temperature control unit; 101. First temperature sensor; 102. Second temperature sensor; 103. First steam feeding assembly; 104. First Steam feed pipe; 105, first steam feed valve; 11, reflux control unit; 111, condensate outlet pipe; 112, reflux pipe; 113, ethanol circulation pipe; 114, first reflux valve; 115, second reflux valve; 12, inlet and outlet flow control unit; 121, adsorption tower feed pipe; 122, adsorption tower discharge pipe; 123, adsorption tower feed valve; 124, adsorption tower discharge valve; 13, second temperature control unit; 131, third temperature sensor; 14, cooler. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0028] Example

[0029] Figure 1 and Figure 2 As shown, an automated control system suitable for large-scale MQ generation waste liquid treatment comprises a wastewater buffer tank 1, a mixer 2, a pH online monitor 3, a neutralization water washing storage tank 4, a distillation tower 5, a filter 6, a molecular sieve adsorption tower 7 and a triple-effect evaporator 8 connected in sequence; the mixer 2 is connected to a sodium hydroxide aqueous solution feeding unit 9, the pH online monitor 3 monitors the pH value after the mixer 2 in real time, and transmits the real-time monitored pH value to a DCS controller; the distillation tower 5 is provided with a first temperature control unit 10 and a reflux control unit 11, the first temperature control unit 10 is used to control the temperature in the distillation tower 5, and the reflux control unit 11 is used to control the reflux ratio of the distillation tower 5; the molecular sieve adsorption tower 7 is provided with an inlet and outlet flow control unit 12, the inlet and outlet flow control unit 12 is used to control the flow at the inlet and outlet of the molecular sieve adsorption tower 7, the triple-effect evaporator 8 is provided with a second temperature control unit 13, the second temperature control unit 13 is used to control the temperature in the triple-effect evaporator 8; the first temperature control unit 10, the inlet and outlet flow control unit 12 and the second temperature control unit 13 are connected to the DCS controller.

[0030] The sodium hydroxide aqueous solution feeding unit 9 comprises a sodium hydroxide aqueous solution feeding pipe 91 and a sodium hydroxide aqueous solution feeding valve 92 arranged on the sodium hydroxide aqueous solution feeding pipe 91, and the sodium hydroxide aqueous solution feeding valve 92 is connected to a DCS controller.

[0031] Wherein, the first temperature control unit 10 includes a first temperature sensor 101, a second temperature sensor 102 and a first steam feed assembly 103, the first temperature sensor 101 is arranged on the bottom of the distillation tower 5, the second temperature sensor 102 is arranged on the top of the distillation tower 5, the first steam feed assembly 103 is connected to the reboiler on the distillation tower 5, the first steam feed assembly 103 includes a first steam feed pipe 104 and a first steam feed valve 105 arranged on the first steam feed pipe 104, and the first temperature sensor 101, the second temperature sensor 102 and the first steam feed valve 105 are connected to the DCS controller.

[0032] Among them, the reflux control unit 11 includes a condensate outlet pipe 111 connected to the cooler 14, and the condensate outlet pipe 111 is connected to the reflux pipe 112 and the ethanol circulation pipe 113. The reflux pipe 112 and the ethanol circulation pipe 113 are respectively provided with a first reflux valve 114 and a second reflux valve 115, and the first reflux valve 114 and the second reflux valve 115 are connected to the DCS control.

[0033] Among them, the inlet and outlet flow control unit 12 includes an adsorption tower feed pipe 121 and an adsorption tower discharge pipe 122 arranged on the molecular sieve adsorption tower 7, and the adsorption tower feed pipe 121 and the adsorption tower discharge pipe 122 are respectively provided with an adsorption tower feed valve 123 and an adsorption tower discharge valve 124, and the adsorption tower feed valve 123 and the adsorption tower discharge valve 124 are connected to the DCS controller.

[0034] The second temperature control unit 13 includes a third temperature sensor 131 and a power component. The third temperature sensor 131 is arranged on the triple-effect evaporator 8 , and the power component is connected to the electric heater on the triple-effect evaporator 8 of the distillation tower 5 .

[0035] Wherein, the wastewater buffer tank 1 is connected to the reaction liquid stratification tank through a connecting pipe.

[0036] An automated control method for large-scale MQ production wastewater treatment, comprising the following steps:

[0037] Step 1: Prepare MQ by the water glass method. The aqueous phase waste liquid and the sodium hydroxide aqueous solution are respectively flowed into the mixer 2 through the wastewater buffer tank 1 and the sodium hydroxide aqueous solution feeding unit 9. The DCS controller controls the feed flow rate of the sodium hydroxide aqueous solution through the sodium hydroxide aqueous solution feeding unit 9 according to the real-time pH value detected by the pH online monitor 3 so that the solution after passing through the mixer 2 is neutral or slightly alkaline;

[0038] Step 2: the solution after the mixer 2 flows through the neutralization water washing storage tank 4 and then flows into the distillation tower 5 for distillation. The DCS controller separates the ethanol and the tower bottom produced liquid through the first temperature control unit 10, the first pressure control unit and the reflux control unit 11. The ethanol flows back to the reactor for reuse, and the tower bottom produced liquid flows into the molecular sieve adsorption tower 7;

[0039] Step 3: The produced liquid from the tower bottom is filtered through the filter 6 to remove mechanical impurities and then enters the molecular sieve adsorption tower 7 for adsorption. The DCS controller controls the flow of the inlet and outlet of the molecular sieve adsorption tower 7 through the inlet and outlet flow control unit 12 to remove impurities and trace MQ resin to obtain a high-salt wastewater impurity-removing liquid with reduced organic matter content, and the impurity-removing liquid flows into the triple-effect evaporator 8;

[0040] Step 4: The impurity removal liquid is evaporated and crystallized in the triple-effect evaporator 8, and the DCS controller obtains industrial salt and treatable wastewater through the second temperature control unit 13.

[0041] Wherein, in the step 1, the flow rate of the aqueous phase waste liquid generated by the water glass method for preparing MQ is 2000-5000 Kg / h; the pH value is controlled at 1-9; and the concentration of the sodium hydroxide aqueous solution is 30-33 wt%.

[0042] Wherein, in the step 2, the top temperature of the distillation tower 5 is controlled at 80-90°C by the first temperature control unit 10, the bottom temperature of the distillation tower 5 is controlled at 100-120°C by the first temperature control unit 10, and the reflux ratio of the distillation tower 5 is controlled to 5-10:1 by the reflux control unit 11.

[0043] Wherein, in the step three, the flow rates at the inlet and outlet of the molecular sieve adsorption tower 7 are controlled to be 1000-2000 kg / h through the inlet and outlet flow control unit 12.

[0044] Wherein, in the step 4, the temperature of the three-effect evaporator 8 is controlled at 110-120° C. by the second temperature control unit 13 .

[0045] The control parameters of each embodiment are shown in Table 1:

[0046] Table 1

[0047]

[0048] The ethanol extracted from the ethanol circulation pipe in each embodiment and the treatable wastewater obtained by the triple-effect evaporator were tested. The parameters of the ethanol and the treatable wastewater in each embodiment are shown in Table 2:

[0049] Table 2

[0050]

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An automated control system suitable for large-scale MQ production wastewater treatment, characterized by: It comprises a wastewater buffer tank, a mixer, a pH online monitor, a neutralization water washing storage tank, a distillation tower, a filter, a molecular sieve adsorption tower and a three-effect evaporator which are connected in sequence; the mixer is connected to a sodium hydroxide aqueous solution feeding unit, the pH online monitor monitors the pH value after the mixer in real time, and transmits the real-time monitored pH value to a DCS controller; the distillation tower is provided with a first temperature control unit and a reflux control unit, the first temperature control unit is used to control the temperature in the distillation tower, and the reflux control unit is used to control the reflux ratio of the distillation tower; the molecular sieve adsorption tower is provided with an inlet and outlet flow control unit, the inlet and outlet flow control unit is used to control the flow at the inlet and outlet of the molecular sieve adsorption tower, the three-effect evaporator is provided with a second temperature control unit, the second temperature control unit is used to control the temperature in the three-effect evaporator; the first temperature control unit, the inlet and outlet flow control unit and the second temperature control unit are connected to the DCS controller.

2. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 1, characterized in that: The sodium hydroxide aqueous solution feeding unit comprises a sodium hydroxide aqueous solution feeding pipe and a sodium hydroxide aqueous solution feeding valve arranged on the sodium hydroxide aqueous solution feeding pipe, and the sodium hydroxide aqueous solution feeding valve is connected to a DCS controller.

3. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 2, characterized in that: The first temperature control unit includes a first temperature sensor, a second temperature sensor and a first steam feed assembly, the first temperature sensor is arranged on the bottom of the distillation tower, the second temperature sensor is arranged on the top of the distillation tower, the first steam feed assembly is connected to the reboiler on the distillation tower, the first steam feed assembly includes a first steam feed pipe and a first steam feed valve arranged on the first steam feed pipe, and the first temperature sensor, the second temperature sensor and the first steam feed valve are connected to the DCS controller.

4. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 3, characterized in that: The reflux control unit includes a condensate outlet pipe connected to the cooler, the condensate outlet pipe is connected to the reflux pipe and the ethanol circulation pipe, the reflux pipe and the ethanol circulation pipe are respectively provided with a first reflux valve and a second reflux valve, the first reflux valve and the second reflux valve are connected to the DCS control.

5. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 4, characterized in that: The inlet and outlet flow control unit includes an adsorption tower feed pipe and an adsorption tower discharge pipe arranged on the molecular sieve adsorption tower, and the adsorption tower feed pipe and the adsorption tower discharge pipe are respectively provided with an adsorption tower feed valve and an adsorption tower discharge valve, and the adsorption tower feed valve and the adsorption tower discharge valve are connected to the DCS controller.

6. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 5, characterized in that: The second temperature control unit comprises a third temperature sensor and a power component. The third temperature sensor is arranged on the triple-effect evaporator. The power component is connected to the electric heater on the triple-effect evaporator of the distillation tower.

7. An automated control system suitable for large-scale MQ production wastewater treatment according to claim 6, characterized in that: The wastewater buffer tank is connected to the reaction liquid stratification tank through a connecting pipe.

8. A control method adopted by an automated control system suitable for large-scale MQ production wastewater treatment according to any one of claims 1 to 7, comprising the following steps: Step 1: The aqueous phase waste liquid and the sodium hydroxide aqueous solution generated by the water glass method for preparing MQ flow into the mixer through the wastewater buffer tank and the sodium hydroxide aqueous solution feeding unit respectively, and the DCS controller controls the feed flow rate of the sodium hydroxide aqueous solution through the sodium hydroxide aqueous solution feeding unit according to the real-time pH value detected by the pH online monitor so that the solution after passing through the mixer is neutral or slightly alkaline; Step 2: The solution after the mixer flows through the neutralization water washing storage tank and then flows into the distillation tower for distillation. The DCS controller separates ethanol and tower bottom produced liquid through the first temperature control unit, the first pressure control unit and the reflux control unit. The ethanol flows back to the reactor for reuse, and the tower bottom produced liquid flows into the molecular sieve adsorption tower; Step 3: The produced liquid from the tower bottom is filtered through a filter to remove mechanical impurities and then enters the molecular sieve adsorption tower for adsorption. The DCS controller controls the flow of the molecular sieve adsorption tower inlet and outlet through the inlet and outlet flow control unit to remove impurities and trace MQ resin to obtain a high-salt wastewater impurity-removing liquid with reduced organic matter content, and the impurity-removing liquid flows into the triple-effect evaporator; Step 4: The impurity removal liquid is evaporated and crystallized in a triple-effect evaporator, and the DCS controller obtains industrial salt and treatable wastewater through the second temperature control unit.

9. An automated control method for large-scale MQ production wastewater treatment according to any one of claim 8, characterized in that: In the step 1, the flow rate of the aqueous phase waste liquid generated by the water glass method for preparing MQ is 2000-5000 Kg / h; the pH value is controlled at 7-9; and the concentration of the sodium hydroxide aqueous solution is 30-33 wt%.

10. An automated control method for large-scale MQ production wastewater treatment according to any one of claim 9, characterized in that: In the step 2, the top temperature of the distillation tower is controlled at 80-90°C by the first temperature control unit, the bottom temperature of the distillation tower is controlled at 100-120°C by the first temperature control unit, and the reflux ratio of the distillation tower is controlled at 5-10:1 by the reflux control unit.

11. An automated control method for large-scale MQ production wastewater treatment according to any one of claim 10, characterized in that: In the step three, the flow rates at the inlet and outlet of the molecular sieve adsorption tower are controlled to be 1000-2000 kg / h through the inlet and outlet flow control units.

12. An automated control method for large-scale MQ production wastewater treatment according to any one of claim 11, characterized in that: In the step 4, the temperature of the three-effect evaporator is controlled at 110-120° C. by a second temperature control unit.

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