System and method for efficiently purifying secondary refrigerant ethylene glycol

Abstract

The invention relates to the technical field of secondary refrigerant ethylene glycol purification, and discloses a secondary refrigerant ethylene glycol efficient purification system which comprises a PLC control unit, a medicament adding unit, a GW transfer-in pump, a decolorizing tank, a filter, a D101 resin tank, a first buffer tank, a D001 cation bed tank, a second buffer tank, a D201 anion bed tank and a temporary storage tank. The agent adding unit comprises a pretreatment agent device, a sulfuric acid agent device, a hydrochloric acid agent device, a sodium hydroxide agent device and a pure water adding device, and the PLC control unit is respectively connected with the decolorizing tank, the anion bed tank, the temporary storage tank and the filter. According to the efficient secondary refrigerant ethylene glycol purification system and method, an ethylene glycol treatment integrated process of flocculation impurity removal and ion exchange is adopted, the ion concentration is effectively reduced, the cleaning effect in the ethylene glycol using process is improved, equipment corrosion is reduced, and technical progress and environmental protection benefits are brought to the ethylene glycol treatment industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coolant glycol purification, in particular to a coolant glycol high-efficiency purification system and method. BACKGROUND

[0002] In the methionine production field, the complex process steps have strict requirements for temperature control, especially in the low-temperature reaction and material cooling process, which puts forward high standards for the performance of the coolant. Glycol can maintain liquid state in extreme temperature environment due to its excellent low-temperature fluidity and stable heat transfer, ensuring the continuous and stable operation of the refrigeration system. At the same time, its sensitive response to temperature changes can realize precise regulation of the reaction system temperature, effectively avoiding the problem of unstable product quality caused by temperature fluctuations. In addition, glycol has good compatibility with various media in the methionine production process and is not easy to react chemically, which can ensure the safety and reliability of the production process, so it has become an ideal coolant widely used in the industry.

[0003] However, during long-term operation, the glycol cooling system faces multiple technical problems: on the one hand, the heat transfer efficiency is significantly reduced due to the formation of a heat insulation layer on the wall of the heat exchange pipe caused by temperature difference accumulation; on the other hand, the introduction of inorganic and organic impurities during operation causes an imbalance in ion concentration, leading to liquid suspension or emulsification, which destroys the stability of the system; in addition, glycol is prone to oxidation, causing the system to acidify and accelerating the degree of equipment corrosion, shortening the service life of the equipment. The existing treatment technology mainly uses a single purification method, which is difficult to realize the coordinated regulation of impurity removal, ion purification and system acid-base balance, and lacks an automatic control mechanism, which cannot accurately adapt to water quality fluctuations under different working conditions, resulting in low purification efficiency and high equipment maintenance cost. SUMMARY

[0004] The present application provides a coolant glycol high-efficiency purification system and method, which adopts a glycol treatment integrated process of flocculation and ion exchange to effectively reduce ion concentration, improve the cleaning effect during the use of glycol, and reduce equipment corrosion, bringing technical progress and environmental benefits to the glycol disposal industry.

[0005] The present application provides a coolant glycol high-efficiency purification system, which comprises a PLC control unit, a reagent adding unit, a GW transfer pump, a decolorizing tank, a filter, a D101 resin tank, a first buffer tank, a D001 positive bed tank, a second buffer tank, a D201 negative bed tank and a temporary storage tank. The reagent adding unit comprises a pretreatment reagent device, a sulfuric acid reagent device, a hydrochloric acid reagent device, a sodium hydroxide reagent device and a pure water adding device. The PLC control unit is connected to the decolorizing tank, the negative bed tank, the temporary storage tank and the filter.

[0006] The pretreatment reagent device and the GW transfer pump are connected to the decoloring tank, the decoloring tank is connected to the filter, and the filter outlet is branched, including a first branched line and a second branched line;

[0007] In the first branched line, the filter is connected to the D101 resin tank, the D101 resin tank is connected to the first buffer tank, the first buffer tank is connected to the D201 negative bed tank, and the sulfuric acid reagent device and the pure water adding device are both connected to the D101 resin tank.

[0008] In the second branched line, the filter is connected to the D001 positive bed tank, the D001 positive bed tank is connected to the second buffer tank, the second buffer tank is connected to the D201 negative bed tank, and the hydrochloric acid reagent device and the pure water adding device are both connected to the D001 positive bed tank.

[0009] The D201 negative bed tank is connected to the temporary storage tank, and the sodium hydroxide reagent device and the pure water adding device are both connected to the D201 negative bed tank.

[0010] The cooling agent glycol GW to be purified enters the decoloring tank through the GW transfer pump, the pretreatment reagent device synchronously adds pretreatment reagent to the decoloring tank, and preliminary turbidity removal, decoloring and partial impurity removal are completed; the treated liquid flows into the filter to further intercept large-particle impurities and activated carbon residues to reduce turbidity; after filtration, the liquid passes through the branched node, enters the D101 resin tank through the first branched line, and enters the D001 positive bed tank through the second branched line, and the sulfuric acid and hydrochloric acid added by the pure water adding device and the corresponding sulfuric acid reagent device and hydrochloric acid reagent device participate in resin regeneration, and the treated liquid is temporarily stored in the first buffer tank and the second buffer tank, respectively, and the liquid of the two buffer tanks is combined and enters the D201 negative bed tank to remove anions, and the finally purified glycol is transported to the temporary storage tank, realizing efficient purification and reuse of the cooling agent.

[0011] Further, the PLC control unit includes a PLC control cabinet, a pH sensor, a conductivity meter and an ammonia nitrogen monitor, the PLC control cabinet is connected to the pH sensor, the conductivity meter and the ammonia nitrogen monitor, respectively, the pH sensor is connected to the decoloring tank and the temporary storage tank, the conductivity meter is connected to the negative bed tank and the temporary storage tank, and the ammonia nitrogen monitor is connected to the filter.

[0012] Further, the pre-treatment agent device adds agents to the decoloring tank, including concentrated ammonia, 20% ferrous sulfate, activated carbon dry powder, and 0.1% PAM, the sulfuric acid agent device adds 5% sulfuric acid to the D101 resin tank, the hydrochloric acid agent device adds 5% hydrochloric acid or 5% sulfuric acid to the D001 positive bed tank, the sodium hydroxide agent device adds 5% sodium hydroxide to the D201 negative bed tank, and the pure water adding device adds pure water to the D101 resin tank, the D001 positive bed tank, and the D201 negative bed tank.

[0013] Further, the decoloring tank is driven by a pump, a first valve is arranged on the pipeline connecting the filter and the D101 resin tank, a second valve is arranged on the pipeline connecting the D101 resin tank and the first buffer tank, a third valve is arranged on the pipeline connecting the filter and the D001 positive bed tank, a fourth valve is arranged on the pipeline connecting the D001 positive bed tank and the second buffer tank, a pump and a fifth valve are arranged in sequence on the pipeline connecting the second buffer tank and the D201 negative bed tank, and a sixth valve is arranged on the pipeline connecting the D201 negative bed tank and the temporary storage tank.

[0014] Further, the decoloring tank is used to receive the glycol GW to be treated, the pH value is adjusted by adding concentrated ammonia, the suspended solids are coagulated by adding 20% ferrous sulfate, the color and odor are removed by adding activated carbon dry powder to adsorb pigments and organic matter, the flocculation effect is strengthened and the impurity settlement is accelerated by adding 0.1% PAM, the initial turbidity and color are removed, and part of the suspended solids and organic pollutants are removed.

[0015] Further, the filter is an automatic backwashing filter, which is used to intercept the solid particles, suspended solids, and activated carbon residues in the liquid treated by the decoloring tank, automatically identify the impurity deposition degree, automatically backwash and discharge sewage without interrupting the system water supply, and continuously maintain the filtering performance.

[0016] Further, the D101 resin tank is filled with strong acid cation exchange resin, 5% sulfuric acid is used as a regenerant to restore the exchange capacity of the resin, and pure water is used for regeneration or flushing, finally, the cation impurities in the first shunt branch liquid are removed by adsorption, and the treated liquid is temporarily stored in the first buffer tank.

[0017] The D001 positive bed tank is filled with strong acid styrene cation exchange resin, 5% hydrochloric acid or 5% sulfuric acid is used as a regenerant, and pure water is used to specifically remove cations in the second shunt branch liquid, and the treated liquid is temporarily stored in the second buffer tank.

[0018] Further, the D201 cathode tank is filled with strong alkaline styrene anion exchange resin, and 5% sodium hydroxide is used as a regenerant to revive the resin, and pure water is used to deeply remove anions in the liquid, so as to complete ion deep purification and make the ethylene glycol reach the recycling standard.

[0019] Further, the pure water adding device provides pure water for the regeneration and flushing links of the D101 resin tank, the D001 anode tank and the D201 cathode tank, so as to avoid introducing new impurities and guarantee the resin regeneration effect and the ethylene glycol quality after purification.

[0020] The application provides a kind of efficient ethylene glycol purification method for coolant, based on the efficient ethylene glycol purification system for coolant as described above, the method specifically includes:

[0021] S1, the ethylene glycol GW to be treated is transported to the decolorizing tank by the GW transfer-in pump, and is sequentially injected with concentrated ammonia water, 20% ferrous sulfate solution, activated carbon dry powder and 0.1% PAM solution.Under the action of the stirrer, ferrous sulfate hydrolysis forms flocculation to adsorb suspended solids, activated carbon adsorbs pigments and organic matter, and PAM promotes flocculation coagulation and sedimentation.The pH value is adjusted to 9.5 by real-time monitoring of the concentrated ammonia water by the pH sensor, and the treated mixed liquid flows into the filter;

[0022] S2, the filtered liquid is dynamically distributed to different treatment paths according to the water quality detection results through the shunt node:

[0023] The first shunt branch: as a high ammonia-nitrogen wastewater branch, the wastewater with NH4 + > threshold value enters the D101 resin tank filled with strong acid cation exchange resin, and removes ammonium ions NH4 + and other cations by ion exchange;

[0024] The second shunt branch: as a conventional wastewater branch, the wastewater with NH4 + < threshold value enters the D001 anode tank filled with strong acid styrene cation exchange resin to deeply remove cations;

[0025] The D101 resin tank and the D001 resin tank both adopt countercurrent regeneration process, and 5% sulfuric acid or hydrochloric acid solution is injected regularly to restore the exchange capacity of the resin in combination with pure water flushing;

[0026] S3, the liquids treated by the D101 resin tank and the D001 resin tank flow into the first buffer tank and the second buffer tank, respectively;

[0027] S4, the buffered liquids are combined and enter the D201 cathode tank filled with strong alkaline styrene anion exchange resin, and remove sulfate ions SO4 2-, chloride ion Cl - When the conductivity meter monitors that the outlet conductivity is greater than 10 muS / cm, the regeneration program is triggered, that is, 5% sodium hydroxide solution is first injected, and then pure water is washed to neutral to restore the adsorption capacity of the resin;

[0028] S5, the treated ethylene glycol is stored in a temporary storage tank, and is monitored in real time through an online conductivity meter and a pH sensor, if the conductivity is greater than 10 muS / cm or the pH is out of the range of 6.5-7.5, the ethylene glycol is automatically returned to the D201 negative bed tank for secondary treatment.

[0029] The present application has the following advantages:

[0030] The present application realizes intelligent regulation and control of the whole purification process by cooperating the PLC control unit with multiple types of sensors, and accurately adapts to different water quality conditions; the pretreatment reagent device cooperates with the decolorizing tank and the filter to effectively remove suspended solids, pigments and impurities, and provides basic conditions for subsequent treatment. The double shunt branch cooperates with the D101 resin tank, the D001 positive bed tank and the D201 negative bed tank to form a multi-stage ion exchange system, and specifically removes anions, cations and ammonia nitrogen. Each resin tank is matched with an independent reagent adding and regeneration system, combined with a pure water adding device, which significantly improves the service life of the resin and the purification efficiency. The system realizes integrated and efficient operation from impurity removal, ion purification to resin regeneration through organic integration and dynamic regulation of each unit, effectively solves the problems of low purification efficiency, easy corrosion of equipment and high operation cost in the traditional process, and greatly improves the reuse quality of the coolant ethylene glycol and the system stability. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the coolant ethylene glycol efficient purification system of the present application.

[0032] Figure 2 It is a flowchart of the coolant ethylene glycol efficient purification method of the present application.

[0033] The implementation of the object of the present application, functional characteristics and advantages will be further described with reference to the accompanying drawings. DETAILED DESCRIPTION

[0034] It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0035] Ethylene glycol, boiling point 197.3℃, melting point-12.9℃, can be miscible with water in any proportion, after miscible with water, the freezing point is significantly reduced, can be used as a refrigerant, but in the long run, ethylene glycol will undergo chemical and physical changes, resulting in color change from yellow to red, and the increase of insoluble substances, resulting in reduced heat transfer efficiency, increased operating costs, and increased corrosion of equipment. Ethylene glycol will undergo oxidation, through intermediates such as hydroxyacetaldehyde, glyoxal, hydroxyacetic acid or aldehyde acetic acid, to form oxalic acid, thus causing the system to acidify and intensifying the corrosion of the equipment; ammonia is often used to transfer energy between refrigerants and diethylene glycol, and in the long run, ammonia may escape into ethylene glycol, and ammonia-containing ethylene glycol further corrodes equipment made of aluminum, iron and copper; ethylene glycol may introduce acid and alkali media in the face of different use conditions during long-term cooling, and if not treated, it will also cause corrosion of metal equipment; ethylene glycol may breed microorganisms during long-term use, plus the introduction of impurities and unknown impurities, resulting in insoluble impurities, suspended / emulsified in the entire ethylene glycol system, resulting in reduced heat transfer efficiency. Methionine GW faces the above problems and needs to be treated before it can be used efficiently.

[0036] GW has four sets of systems, two sets of-10℃ and two sets of-20℃, which are separate systems, and the impurities introduced during use are also different, as follows:

[0037]

[0038]

[0039] The problems are as follows:

[0040] a. The color and turbidity are too high, and a heat insulation layer may be formed on the wall of the heat exchange tube due to temperature difference accumulation, or the internal heat transfer efficiency may be poor.

[0041] b. The ions exceed the standard, which may cause corrosion of the pipe material during use and intensify the problem.

[0042] c. The four sets of systems are independent, and the water introduced and the ethylene glycol lost during treatment need to be calculated and added separately.

[0043] d. The four sets of systems are independent, and continuous or intermittent treatment each has advantages and disadvantages.

[0044] The present application provides a high-efficiency purification system and method for refrigerant ethylene glycol, which adopts a flocculation and ion exchange integrated process for ethylene glycol treatment, realizes turbidity test not higher than 10NTU, colorimetric test not higher than 50APHA, effectively reduces ion concentration, ethylene glycol loss rate not higher than 5%, ethylene glycol water content not higher than 10%, improves the cleaning effect during use of ethylene glycol, reduces equipment corrosion, and brings technical progress and environmental protection benefits to the ethylene glycol disposal industry.

[0045] AsFigure 1 As shown, the application provides a high-efficiency coolant glycol purification system, which comprises a PLC control unit, a medicament adding unit, a GW transfer pump, a decolorizing tank, a filter, a D101 resin tank, a first buffer tank, a D001 cation bed tank, a second buffer tank, a D201 anion bed tank and a temporary storage tank, the medicament adding unit comprises a pretreatment medicament device, a sulfuric acid medicament device, a hydrochloric acid medicament device, a sodium hydroxide medicament device and a pure water adding device, and the PLC control unit is connected with the decolorizing tank, the anion bed tank, the temporary storage tank and the filter respectively.

[0046] The pretreatment medicament device and the GW transfer pump are connected with the decolorizing tank, the decolorizing tank is connected with the filter, and the filter outlet is branched into a first branched pipeline and a second branched pipeline.

[0047] In the first branched pipeline, the filter is connected with the D101 resin tank, the D101 resin tank is connected with the first buffer tank, the first buffer tank is connected with the D201 anion bed tank, and the sulfuric acid medicament device and the pure water adding device are connected with the D101 resin tank.

[0048] In the second branched pipeline, the filter is connected with the D001 cation bed tank, the D001 cation bed tank is connected with the second buffer tank, the second buffer tank is connected with the D201 anion bed tank, and the hydrochloric acid medicament device and the pure water adding device are connected with the D001 cation bed tank.

[0049] The D201 anion bed tank is connected with the temporary storage tank, and the sodium hydroxide medicament device and the pure water adding device are connected with the D201 anion bed tank. The decolorizing tank and the filter are driven by a pump, a first valve is arranged on the pipeline connecting the filter and the D101 resin tank, a second valve is arranged on the pipeline connecting the D101 resin tank and the first buffer tank, a third valve is arranged on the pipeline connecting the filter and the D001 cation bed tank, a fourth valve is arranged on the pipeline connecting the D001 cation bed tank and the second buffer tank, a pump and a fifth valve are arranged in sequence on the pipeline connecting the second buffer tank and the D201 anion bed tank, and a sixth valve is arranged on the pipeline connecting the D201 anion bed tank and the temporary storage tank.

[0050] The treatment process of the application is as follows:

[0051] GW (the glycol to be treated as the system processing object) is the glycol raw material containing impurities (such as suspended solids, ions, etc.) and needing to be purified for recycling. The glycol GW to be purified enters the decoloring tank through the GW pump, the pretreatment reagent device synchronously adds the pretreatment reagent into the decoloring tank, and the preliminary turbidity removal, decoloring and partial impurity removal are completed; the treated liquid flows into the filter to further intercept the large-particle impurities and activated carbon residues to reduce the turbidity; after the filtration, the liquid passes through the shunt node, enters the D101 resin tank through the first shunt branch, and enters the D001 positive bed tank through the second shunt branch, and the sulfuric acid and hydrochloric acid added by the pure water adding device and the corresponding sulfuric acid reagent device and hydrochloric acid reagent device participate in the resin regeneration, and the treated liquid is temporarily stored in the first buffer tank and the second buffer tank respectively, and the liquid of the two buffer tanks is combined to enter the D201 negative bed tank to remove anions, and the finally purified glycol is transported to the temporary storage tank to realize the efficient purification and recycling of the glycol.

[0052] (1) PLC control unit

[0053] The PLC control unit comprises a PLC control cabinet, a pH sensor, a conductivity meter and an ammonia nitrogen monitor, the PLC control cabinet is connected with the pH sensor, the conductivity meter and the ammonia nitrogen monitor respectively, the pH sensor is connected with the decoloring tank and the temporary storage tank, the conductivity meter is connected with the negative bed tank and the temporary storage tank, and the ammonia nitrogen monitor is connected with the filter.

[0054] (2) Reagent adding unit

[0055] The reagent adding unit comprises a pretreatment reagent device, a sulfuric acid reagent device, a hydrochloric acid reagent device, a sodium hydroxide reagent device and a pure water adding device, the reagent added by the pretreatment reagent device into the decoloring tank comprises concentrated ammonia water, 20% ferrous sulfate, activated carbon dry powder and 0.1% PAM, the sulfuric acid reagent device adds 5% sulfuric acid into the D101 resin tank, the hydrochloric acid reagent device adds 5% hydrochloric acid or 5% sulfuric acid into the D001 positive bed tank, the sodium hydroxide reagent device adds 5% sodium hydroxide into the D201 negative bed tank, and the pure water adding device adds pure water into the D101 resin tank, the D001 positive bed tank and the D201 negative bed tank.

[0056] (3) Decoloring tank

[0057] The decoloring tank is used for receiving the glycol GW to be treated, adjusting the pH value by adding concentrated ammonia water, making the suspended solids coagulate by adding 20% ferrous sulfate, adsorbing the colorants and organic matters by adding activated carbon dry powder to decolor and remove odor, and strengthening the flocculation effect and accelerating the impurity settlement by adding 0.1% PAM to realize the preliminary turbidity removal, decoloring, removal of part of the suspended solids and organic pollutants.

[0058] (4) Filter

[0059] The filter is an automatic backwashing filter for filtering the effluent of the decoloring tank, intercepting solid particles, suspended solids, activated carbon residues and other impurities in the liquid treated by the decoloring tank, avoiding the blockage of subsequent equipment such as the positive bed tank, and ensuring smooth operation of the system; automatically identifying the deposition degree of impurities, automatically backwashing and discharging sewage without interrupting the water supply of the system, continuously maintaining the filtering performance, providing clean and stable liquid flow for the subsequent ion exchange link, and helping to improve the purification effect of the cold carrier glycol and the system operation efficiency.

[0060] (5) D101 resin tank

[0061] The D101 resin tank is filled with strong acid cation exchange resin, uses 5% sulfuric acid as a regenerant to restore the exchange capacity of the resin, and uses pure water to participate in regeneration or flushing, finally adsorbs and removes cation impurities (such as calcium, magnesium, iron ions, etc.) in the liquid of the first shunt branch, and temporarily stores the treated liquid in the first buffer tank.

[0062] (6) D001 positive bed tank

[0063] The D001 positive bed tank is filled with strong acid styrene cation exchange resin, uses 5% hydrochloric acid or 5% sulfuric acid as a regenerant, and cooperates with pure water to specifically remove cations in the liquid of the second shunt branch, and temporarily stores the treated liquid in the second buffer tank, forming a multi-stage cation purification with D101.

[0064] The first buffer tank and the second buffer tank temporarily store the liquid treated by the positive bed tank, stabilize the flow and homogenize the water quality, provide a stable liquid source for subsequent negative bed tank treatment, and avoid impacting the negative bed resin.

[0065] (7) D201 negative bed tank

[0066] The D201 negative bed tank is filled with strong base styrene anion exchange resin, uses 5% sodium hydroxide as a regenerant to revive the resin, and simultaneously removes anions (such as sulfate, chloride, etc.) in the liquid with pure water, to complete ion deep purification and make the glycol meet the reuse standard.

[0067] The temporary storage tank stores the qualified glycol treated by the negative bed tank as the purified cold carrier, waiting to be reused to the refrigeration system.

[0068] (8) Pure water adding device

[0069] The pure water adding device provides pure water for the regeneration and flushing links of the D101 resin tank, D001 positive bed tank and D201 negative bed tank, to avoid introducing new impurities and ensure the regeneration effect of the resin and the quality of the purified glycol.

[0070] The above devices cooperate to realize efficient purification and recycling of the coolant glycol through the process of pretreatment turbidity removal, cation stepwise removal, and anion deep purification.

[0071] As shown in Figure 2 The application also provides an efficient coolant glycol purification method based on the efficient coolant glycol purification system.

[0072] S1, pretreatment flocculation turbidity removal

[0073] The coolant glycol GW to be treated is delivered by the GW transfer-in pump to the decoloring tank, 20% concentrated ammonia water is injected to adjust the pH to about 9.5 (first stage), after uniform stirring, 20% ferrous sulfate solution is injected at about 0.1-1% until the color becomes black green and there is no white suspended matter, after stirring for 5-20 min, 0.1-0.5% of activated carbon dry powder is added and stirring is continued for 10-30 min, finally 0.1% PAM is added dropwise with a maximum of 0.2% and uniform stirring is performed, and then the filter is started.

[0074] Under the action of the stirrer, the ferrous sulfate hydrolysis forms flocculation bodies to adsorb suspended matter, the activated carbon adsorbs pigments and organic matter, and the PAM promotes flocculation body coagulation and sedimentation; the pH value is adjusted to 9.5 by real-time monitoring of the concentrated ammonia water by the pH sensor, and the treated mixed liquid flows into the filter.

[0075] S2, flow splitting and cation removal by the cation bed

[0076] The filtered liquid is dynamically distributed to different treatment paths according to the water quality detection results at the flow splitting node:

[0077] The first flow splitting branch: as a high ammonia nitrogen wastewater branch, the wastewater with NH4 + > threshold value enters the D101 resin tank filled with strong acid cation exchange resin to remove ammonium ions NH4 + and other cations by ion exchange. In the first flow splitting branch, the filtrate only uses D101 resin adsorption to remove excess ammonia into the system, the weak acid resin has a large capacity and has a small effect on the water content of the system, but the salt-forming ions cannot be removed.

[0078] The second flow splitting branch: as a conventional wastewater branch, the wastewater with NH4 + < threshold value enters the D001 cation bed tank filled with strong acid styrene cation exchange resin to deeply remove cations. In the second flow splitting branch, the filtrate enters the D001 cation bed tank, is soaked, and then flows into the buffer tank (pH < 3) by itself, the buffer tank flows into the D201 anion bed tank (pH about 7-8, the pH of the first few batches may be greater than 8, and the pH is adjusted after mixing with the last batches), is soaked, and then flows into the temporary storage tank by itself, and a large amount of D001 resin is used.

[0079] In addition, the filtrate can also use D101 resin adsorption, excess ammonia is removed into D001 positive bed tank, soak after self-flow into buffer tank (pH <3), buffer tank into D201 negative bed tank (pH about 7~8, the first batch of pH because D201 can be greater than 8, and adjust the pH after mixing with the latter batch), soak after self-flow into the temporary storage tank. The advantages of the first shunt branch and the second shunt branch are combined, but a set of resin tank needs to be added.

[0080] The D101 resin tank and D001 resin tank both use countercurrent regeneration process, and 5% sulfuric acid or hydrochloric acid solution is injected regularly, and pure water is washed to restore the exchange capacity of the resin.

[0081] S3, buffering and pH adjustment

[0082] The liquid treated by the D101 resin tank and the D001 resin tank flows into the first buffer tank and the second buffer tank respectively; real-time monitoring can also be performed through the pH sensor, and dilute sulfuric acid or sodium hydroxide solution is added to the buffer tank to accurately adjust the pH value to 7.0±0.5, so as to ensure that the liquid entering the negative bed tank is neutral and avoid the impact of acid and alkali on the negative bed resin.

[0083] S4, negative bed de-anion

[0084] The buffered liquid is combined into the D201 negative bed tank, which is filled with strong basic styrene anion exchange resin. When the outlet conductivity of the conductivity instrument is greater than 10 μS / cm, the regeneration program is triggered, that is, 5% sodium hydroxide solution is first injected, and then pure water is washed to neutral to restore the adsorption capacity of the resin.

[0085] Among them, before the regeneration of the resin, the dry resin is controlled, the valve of the resin tank is closed, acid and alkali solution is added for soaking, and after the soaking is completed, the desalinated water is soaked several times and then sprayed to neutral and chloride and sodium ion <50ppm. Controlling the dry resin requires a certain amount of time to ensure that less water is introduced. In order to reduce the loss of GW, a small amount of water can be used to spray the resin before regeneration.

[0086] In addition, before the next step, five-step intermittent regeneration can also be performed, and the process is as follows:

[0087] When the inlet and outlet conductivity difference of the resin tank is less than or equal to 5 μS / cm, the five-step regeneration process is started:

[0088] a. Vacuum drying: turn on the vacuum unit (-0.05 MPa) to quickly drain the residual ethylene glycol between the resin layers and recover to the temporary storage tank.

[0089] b. Pulse regeneration: through the pulse regeneration pump, the regenerant (acid / alkali solution) and compressed air are alternately injected to form pulse shock and strengthen the regeneration effect.

[0090] c. Temperature change flushing: first flush with 40℃ hot water for 5min, then flush with 25℃ pure water until pH neutral, remove residual regenerant.

[0091] d. Ultrasonic activation: start the ultrasonic control cabinet (40kHz), make the resin particles vibrate at high frequency, strip the adsorbed impurities, and restore activity.

[0092] e. Gradient water replenishment: inject pure water according to 20%, 40%, 60%, 80%, and 100% gradient, balance the water content of the resin layer, and prevent sudden changes from causing breakage.

[0093] S5, closed loop verification and reuse of purified liquid

[0094] The treated ethylene glycol is stored in a temporary storage tank and is monitored in real time by an online conductivity meter and a pH sensor. If the conductivity is greater than 10 μS / cm or the pH is out of the range of 6.5-7.5, it is automatically returned to the D201 negative bed tank for secondary treatment. When the standard is met, it is delivered to the refrigeration system for circulation by a frequency conversion pump. Meanwhile, a PLC control cabinet optimizes the parameters of each link according to historical data, including the amount of reagent added and the regeneration cycle, to form a closed loop control system, ensuring the purification efficiency and stability.

[0095] In view of the problem that the high color and turbidity of ethylene glycol leads to low heat transfer efficiency of the internal system, the present application adopts a flocculation impurity removal color and turbidity removal process. By adding a flocculating agent, suspended particles in water are aggregated to form flocculent bodies, which adsorb organic impurities in water, further efficiently removing the color and turbidity of ethylene glycol, improving the color and turbidity removal effect, and realizing that the turbidity test is not higher than 10 NTU and the colority test is not higher than 50 APHA.

[0096] In view of the problem that ethylene glycol contains a large amount of inorganic impurities during long-term use, and the ions are over-standard, leading to serious corrosion of pipe equipment. The present application adopts an ion exchange process, fills cation and anion exchange resins, adsorbs cation and anion impurities in ethylene glycol, deeply removes inorganic impurities in the running process of ethylene glycol, realizes that the chloride ion is <700 ppm, the sulfate radical is <2500 ppm, the iron is <2 ppm, and the total alkalinity is <1100 ppm.

[0097] To sum up, the application realizes intelligent regulation and control of the whole purification process by the cooperation of the PLC control unit and multiple types of sensors, and accurately adapts to different water quality conditions; the pretreatment reagent device cooperates with the decoloring tank and the filter to effectively remove suspended solids, pigments and impurities, thereby providing basic conditions for subsequent treatment. The double shunt branch cooperates with the D101 resin tank, the D001 positive bed tank and the D201 negative bed tank to form a multi-stage ion exchange system, and specifically removes anions, cations and ammonia nitrogen. Each resin tank is matched with an independent reagent adding and regeneration system, and combined with the pure water adding device, the service life of the resin and the purification efficiency are significantly improved. Through the organic integration and dynamic regulation of each unit, the system realizes integrated and efficient operation from impurity removal, ion purification to resin regeneration, effectively solves the problems of low purification efficiency, easy corrosion of equipment and high operation cost in the traditional process, and greatly improves the reuse quality of the coolant glycol and the system stability.

[0098] It should be noted that in this document, the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, devices, articles or methods that include a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, devices, articles or methods. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, device, article or method that includes the element.

[0099] The above description is only the preferred embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent process transformation according to the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A high efficiency purification system for a coolant glycol, characterized by, It includes PLC control unit, medicament adding unit, GW transfer pump, decoloring tank, filter, D101 resin tank, first buffer tank, D001 positive bed tank, second buffer tank, D201 negative bed tank and temporary storage tank, the medicament adding unit includes pretreatment medicament device, sulfuric acid medicament device, hydrochloric acid medicament device, sodium hydroxide medicament device and pure water adding device, the PLC control unit is connected with the decoloring tank, negative bed tank, temporary storage tank and filter respectively; The pretreatment medicament device and GW transfer pump are connected with the decoloring tank, the decoloring tank is connected with the filter, and the filter outlet is branched to include first branched line and second branched line; In the first branched line, the filter is connected with the D101 resin tank, the D101 resin tank is connected with the first buffer tank, the first buffer tank is connected with the D201 negative bed tank, and the sulfuric acid medicament device and pure water adding device are connected with the D101 resin tank; In the second branched line, the filter is connected with the D001 positive bed tank, the D001 positive bed tank is connected with the second buffer tank, the second buffer tank is connected with the D201 negative bed tank, and the hydrochloric acid medicament device and pure water adding device are connected with the D001 positive bed tank; The D201 negative bed tank is connected with the temporary storage tank, and the sodium hydroxide medicament device and pure water adding device are connected with the D201 negative bed tank; The cold carrier glycol GW to be purified is transferred into the decoloring tank through the GW transfer pump, the pretreatment medicament device synchronously adds pretreatment medicament into the decoloring tank, and preliminary turbidity removal, decoloring and partial impurity removal are completed; the treated liquid flows into the filter to further intercept large-particle impurities and activated carbon residues to reduce turbidity; after filtration, the liquid is branched at a branched node, enters the D101 resin tank through the first branched line and enters the D001 positive bed tank through the second branched line, the pure water adding device and the sulfuric acid and hydrochloric acid added by the corresponding sulfuric acid medicament device and hydrochloric acid medicament device participate in resin regeneration, and the treated liquid is temporarily stored in the first buffer tank and second buffer tank respectively, and the liquid in the two buffer tanks is combined and enters the D201 negative bed tank to remove anions, and finally the purified glycol is transported to the temporary storage tank to realize efficient purification and reuse of the cold carrier.

2. The high-efficiency coolant glycol purification system of claim 1, wherein, The PLC control unit includes PLC control cabinet, pH sensor, conductivity meter and ammonia nitrogen monitor, the PLC control cabinet is connected with the pH sensor, conductivity meter and ammonia nitrogen monitor respectively, the pH sensor is connected with the decoloring tank and temporary storage tank, the conductivity meter is connected with the negative bed tank and temporary storage tank, and the ammonia nitrogen monitor is connected with the filter.

3. The high efficiency coolant glycol purification system of claim 1, wherein, The pre-treatment agent device adds agents into the decoloring tank, including concentrated ammonia, 20% ferrous sulfate, activated carbon dry powder, 0.1% PAM, the sulfuric acid agent device adds 5% sulfuric acid into the D101 resin tank, the hydrochloric acid agent device adds 5% hydrochloric acid or 5% sulfuric acid into the D001 positive bed tank, the sodium hydroxide agent device adds 5% sodium hydroxide into the D201 negative bed tank, and the pure water adding device adds pure water into the D101 resin tank, the D001 positive bed tank and the D201 negative bed tank.

4. The high-efficiency coolant glycol purification system of claim 1, wherein, The decoloring tank is driven by a pump, a first valve is arranged on the pipeline connecting the filter and the D101 resin tank, a second valve is arranged on the pipeline connecting the D101 resin tank and the first buffer tank, a third valve is arranged on the pipeline connecting the filter and the D001 positive bed tank, a fourth valve is arranged on the pipeline connecting the D001 positive bed tank and the second buffer tank, a pump and a fifth valve are arranged in sequence on the pipeline connecting the second buffer tank and the D201 negative bed tank, and a sixth valve is arranged on the pipeline connecting the D201 negative bed tank and the temporary storage tank.

5. The high-efficiency coolant glycol purification system of claim 3, wherein, The decoloring tank is used for receiving the glycol GW to be treated, the pH value is adjusted by adding concentrated ammonia, the suspended solids are coagulated by adding 20% ferrous sulfate, the activated carbon dry powder is added to adsorb the colorants and organic matters to decolor and remove odor, and 0.1% PAM is added to strengthen the flocculation effect and accelerate the settlement of impurities, so as to realize preliminary turbidity removal, decoloring, and removal of part of suspended solids and organic pollutants.

6. The high-efficiency coolant glycol purification system of claim 5, wherein, The filter is an automatic backwashing filter, which is used for intercepting solid particles, suspended solids and activated carbon residues in the liquid treated by the decoloring tank, automatically identifying the deposition degree of impurities, and automatically backwashing and discharging sewage without interrupting the water supply of the system, so as to continuously maintain the filtering performance.

7. The high-efficiency coolant glycol purification system of claim 3, wherein, The D101 resin tank is filled with strong acid cation exchange resin, 5% sulfuric acid is used as a regenerant to restore the exchange capacity of the resin, and pure water is used for regeneration or flushing, finally, the cation impurities in the liquid of the first shunt branch are removed by adsorption, and the treated liquid is temporarily stored in the first buffer tank. The D001 positive bed tank is filled with strong acid styrene cation exchange resin, 5% hydrochloric acid or 5% sulfuric acid is used as a regenerant, and pure water is used to remove cations in the liquid of the second shunt branch, and the treated liquid is temporarily stored in the second buffer tank.

8. The high-efficiency purification system for coolant glycol according to claim 3, wherein The D201 negative bed tank is filled with strong alkali styrene anion exchange resin, 5% sodium hydroxide is used as a regenerant to restore the resin, and pure water is used to remove anions in the liquid, so as to complete the deep purification of ions and make the glycol meet the reuse standard.

9. The high-efficiency coolant glycol purification system of claim 3, wherein, The pure water adding device provides pure water for the regeneration and flushing links of the D101 resin tank, the D001 positive bed tank and the D201 negative bed tank, so as to avoid introducing new impurities and ensure the regeneration effect of the resin and the quality of the purified glycol.

10. A method for high efficiency purification of a coolant glycol, characterized by, The glycol high-efficiency purification system based on any one of claims 1-9, the method specifically comprises: S1, the glycol GW to be treated is pumped into the decoloring tank by the GW transfer-in pump, and concentrated ammonia water, 20% ferrous sulfate solution, activated carbon dry powder and 0.1% PAM solution are sequentially injected, under the action of the stirrer, the ferrous sulfate hydrolysis forms flocculation to adsorb suspended solids, activated carbon adsorbs pigments and organic matter, and PAM promotes flocculation to coagulate and settle; the pH value is adjusted to 9.5 by real-time monitoring of the concentrated ammonia water by the pH sensor, and the treated mixed liquid flows into the filter; S2, the filtered liquid is dynamically distributed to different treatment paths according to the water quality detection results through the shunt node: The first shunt branch: as a high ammonia nitrogen wastewater branch, the wastewater with NH4 + > threshold value detected by ammonia nitrogen monitor enters D101 resin tank filled with strong acid type cation exchange resin, and ammonium ion NH4 + and other cations are removed by ion exchange. Second shunt branch: as a conventional wastewater branch, NH4 + Wastewater with threshold value enters D001 cation bed tank, filled with strong acid styrene cation exchange resin, and deeply removes cations; The D101 resin tank and the D001 resin tank both adopt countercurrent regeneration process, and 5% sulfuric acid or hydrochloric acid solution is injected regularly, and pure water is used for flushing to restore the exchange capacity of the resin; S3, the liquids treated by the D101 resin tank and the D001 resin tank flow into the first buffer tank and the second buffer tank respectively; S4, the buffered liquid is merged into the D201 negative bed tank filled with strong alkaline styrene anion exchange resin to remove sulfate SO4 by ion exchange 2- , chloride Cl - When the conductivity meter monitors that the outlet conductivity is >10 μS / cm, the regeneration program is triggered, that is, 5% sodium hydroxide solution is first injected, and then pure water is washed to neutral to restore the adsorption capacity of the resin; S5, the treated glycol is stored in the temporary storage tank, and real-time monitoring is performed by the online conductivity meter and the pH sensor, if the conductivity is >10 μS / cm or the pH is out of the range of 6.5-7.5, it is automatically returned to the D201 cathode tank for secondary treatment.

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