A preparation process of chelating agent solution applied to fly ash solidification system

Abstract

The present invention discloses a preparation process of a chelating agent solution applied to a fly ash solidification system, which includes steps such as pipeline layout, initial water addition, first addition of the chelating agent stock solution, initial stirring, online concentration adjustment, initial use, preparation of chelating agent solution supplement, and reuse of chelating agent solution. Through special pipeline layout, the present invention can not only realize a method for preparing chelating agent solution by a pipeline circulation mixing method without stirring and storage, but also gradually reduce the flow rate of the stock solution or water through the distribution and flow control of each pipeline, so as to achieve the standard concentration by gradually approaching the concentration noise reduction curve to the standard concentration horizontal line; this online concentration adjustment method is rapid and sensitive, and during the feeding, preparation and concentration adjustment processes, the system circulates continuously, eliminating the risk of deposition of chelating agent solution or pipeline blockage; compared with the existing conventional preparation system, the present invention reduces the chelating agent solution stirrer and solution storage tank, reducing the failure points; and the process is simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of fly ash solidification treatment systems, and particularly to a chelating agent solution preparation process applied to a fly ash solidification system. Background Art

[0002] In the treatment of waste incineration tail gas, fly ash is recovered from the flue gas purification system and collected in a fly ash bin, and then quantitatively sent to a fly ash kneader. Each time fly ash is treated, corresponding proportion of water or leachate is input (some formula solidification matrix uses materials such as cement), and the required heavy metal solidification stabilizer is injected into the kneader. After fly ash, cement, water (or landfill leachate) and the heavy metal stabilizer are briefly stirred in the kneader, the gate can be opened for discharging. The treated fly ash falls into the lower ton bags and can be transported to a general domestic waste landfill after 24 hours of curing (subsequent reaction).

[0003] In the whole fly ash solidification treatment system, the preparation of the binder (chelating agent solution) is generally carried out in a preparation tank with a stirrer. The chelating agent and water are fully mixed by pump circulation to prepare a chelating agent solution. According to the subsequent solidification dosage requirement or weighing requirement, the prepared chelating agent solution also needs to be put into a storage tank for future use.

[0004] However, due to the poor stability and easy adhesion of the chelating agent solution for fly ash solidification, the stirrer and the solution storage tank often become fault points, and it is very inconvenient to handle these two, the cleaning is troublesome, and it is easy to cause the shutdown of the entire fly ash solidification treatment system, which urgently needs to be improved. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies existing in the prior art and propose a chelating agent solution preparation process applied to a fly ash solidification system.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A chelating agent solution preparation process applied to a fly ash solidification system includes the following steps:

[0008] 1) Pipeline layout:

[0009] A 2# pipeline is provided at the top of the chelating agent dilution tank for connecting with the main process water pipeline. The 2# pipeline is provided with a 2# switch valve and a supporting flowmeter for controlling the water inlet flow rate;

[0010] A 4# circulation pipeline is set from the bottom to the top of the chelating agent dilution tank, which is used to circulate the liquid system from the bottom to the liquid level at the top of the tank. The 4# circulation pipeline is provided with a detection pipe section and a 4# switch valve. The two detection pipe sections are connected in parallel and are used as spares for each other. Any one of the detection pipe sections is provided with a delivery pump and a sampling and detection branch pipe. Any one of the detection pipe sections is also opened or closed through a solenoid valve. The delivery pump of the 4# circulation pipeline is provided with a controller, which is used to control the power and delivery flow rate of the delivery pump. The sampling and detection branch pipe is used to detect the concentration and viscosity in the pipeline, so as to judge whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal;

[0011] A 1# pipeline is led out between the pipe orifice near the bottom of the chelating agent dilution tank and the detection pipe section, which is used to connect to the bottom of the chelating agent stock solution tank. The 1# pipeline is successively provided with a delivery pump, a manual valve and a flow control pipe section. The flow control pipe section is opened or closed by two solenoid valves, and is internally provided with a 1# switch valve and a supporting flowmeter. The flow control pipe section is connected in parallel with a maintenance standby pipe end, which is used to supply the chelating agent stock solution to the chelating agent dilution tank through the delivery pump when the inside of the flow control pipe section and its equipment need to be maintained. Check valves are respectively arranged at both ends of the flow control pipe section to prevent the liquid in the 4# circulation pipeline from flowing back into the 1# pipeline;

[0012] Therefore, the chelating agent stock solution in the 1# pipeline can enter the chelating agent dilution tank in two directions. One is to directly pour it into the bottom of the chelating agent dilution tank in a short distance, and the other is to enter the top of the chelating agent dilution tank through the detection pipe section and the 4# switch valve in a long distance. It can be used according to actual needs. For example, if the delivery flow rate of the delivery pump in the 1# pipeline is controlled to be greater than the delivery flow rate of the delivery pump in the detection pipe section, the chelating agent stock solution can be directly poured into the bottom of the chelating agent dilution tank. This situation can be used to quickly supplement the concentration in the chelating agent dilution tank;

[0013] A 3# pipeline is led out between the detection pipe section and the 4# switch valve, which is used to connect to the top of the water weighing and metering tank. The 3# pipeline is provided with a 3# switch valve, which is used to control the introduction of the chelating agent solution into the water weighing and metering tank for weighing;

[0014] The bottom of the water weighing and metering tank is connected to the mixer through a pipeline, and a solenoid valve, a switch valve and a booster pump are also arranged in the pipeline, which are used to control the flow rate and pressure of the chelating agent solution, so as to facilitate the fly ash solidification treatment;

[0015] 2) Initial water addition:

[0016] Open the 2# switch valve to allow water to enter the inlet of the chelating agent dilution tank, and control the water volume to reach the required chelating agent concentration through the level control, and then close the 2# switch valve;

[0017] 3) First addition of chelating agent stock solution:

[0018] Close the 3# on-off valve, open the 4# on-off valve, open one of the inspection pipe sections, open the 1# on-off valve and the transfer pump in the 1# pipeline, close the solenoid valve near the nozzle at the bottom of the chelating agent dilution tank, and let the undiluted chelating agent enter the top of the chelating agent dilution tank through the inspection pipe section and the 4# on-off valve, and enter the middle chelating agent dilution tank from above the water surface;

[0019] 4) Initial stirring:

[0020] Interlock control the flow rate of the undiluted chelating agent through the flowmeter to reach the required dosage of the chelating agent at the desired concentration. Close the 1# on-off valve and the transfer pump in the 1# pipeline, open the solenoid valve near the nozzle at the bottom of the chelating agent dilution tank, and let the liquid in the chelating agent dilution tank pass through the 4# circulation pipeline and continuously operate for 5 - 10 minutes. Use the sampling and detection branch pipe to detect the concentration and viscosity in the pipeline to determine whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal;

[0021] 5) Online concentration adjustment:

[0022] When the concentration is too low, open the 1# on-off valve and the transfer pump in the 1# pipeline for temporary liquid addition. If the concentration is too high, open the 2# on-off valve for water addition. Observe the concentration change curve and compare it with the standard concentration horizontal line. Control the flowmeter through the controller to gradually reduce the flow rate of the 1# pipeline or the 2# pipeline, so that the concentration change curve gradually approaches the standard concentration horizontal line, and finally form a noise reduction curve that is infinitely close to the standard concentration horizontal line. When the error of the concentration fluctuation ≤ 2% of the standard concentration, it can be considered that the standard concentration is reached;

[0023] 6) Initial use:

[0024] Wait until the concentration and viscosity change curves tend to be stable and both the concentration and viscosity meet the usage requirements, which proves that the preparation of the chelating agent solution is completed. Then open the 3# on-off valve and close the 4# on-off valve, and let the chelating agent solution pass through the weighing and pressurization process and be pumped into the mixer for fly ash solidification operation;

[0025] 7) Supplementary preparation of chelating agent solution:

[0026] During the time when the chelating agent solution is being weighed and used for fly ash solidification, supplement and prepare the chelating agent solution, that is, close the 3# on-off valve, open the 2# on-off valve, the 4# on-off valve, the 1# on-off valve and the transfer pump in the 1# pipeline, open the solenoid valve near the nozzle at the bottom of the chelating agent dilution tank, and control the flow rate of the transfer pump in the inspection pipe section through the controller to be 2 - 3 times the flow rate of the transfer pump in the 1# pipeline, so that the newly added undiluted chelating agent and the chelating agent solution coming out from the bottom of the chelating agent dilution tank are mixed and flow, and pass through the inspection pipe section and the 4# on-off valve, and the newly added process water is put into the upper part of the liquid level of the chelating agent dilution tank for feeding and circulating mixing while feeding;

[0027] 8) Repeated use of chelating agent solution:

[0028] Repeat step 5) to make the concentration fluctuation error on the concentration curve in the detection pipe section ≤ 2% of the standard concentration, then it can be considered that the standard concentration is reached. At this time, completely close the 2# switching valve, 4# switching valve, 1# switching valve in the 1# pipeline and the transfer pump, open the 3# switching valve, so that the chelating agent solution replenishes the water weighing metering tank again, weighs and pressurizes the pump into the mixer, and conducts a new round of fly ash solidification operation.

[0029] Preferably, a drain pipe is provided at the bottom of the chelating agent dilution tank, which is used to discharge the chelating agent solution that has not been used for a long time during major repairs to prevent pipeline blockage caused by sedimentation at the bottom of the tank, or for the wastewater for cleaning the tank body.

[0030] Preferably, a drain pipe is provided at the bottom of the chelating agent stock solution tank, which is used to discharge the chelating agent stock solution that has not been used for a long time during major repairs to prevent pipeline blockage caused by sedimentation at the bottom of the tank, or for the wastewater for cleaning the tank body.

[0031] Preferably, liquid level gauges are provided on the sides of both the chelating agent dilution tank and the chelating agent stock solution tank for observing the liquid level.

[0032] Preferably, a thermometer, a pH meter, a concentration meter and a viscometer are provided in the sampling detection branch pipe to comprehensively determine the state of the liquid in the detection pipeline and feedback it to the controller. The controller and each device in the sampling detection branch pipe are connected to a computer display screen to display the numerical change curves of each detection device over time. Among them, the concentration / time curve is also configured with a standard concentration level for comparison; the display interface of the controller displays each solenoid valve, each switching valve (including the 1#, 2#, 3# and 4# switching valves), each flow meter, the booster pump and other transfer pumps to control the flow direction and flow rate of each pipe section of the entire system. That is, it is necessary to set the transfer pump of the 4# circulation pipeline in advance to be connected to each solenoid valve, each switching valve (including the 1#, 2#, 3# and 4# switching valves), each flow meter, the booster pump and other transfer pumps through the foot wire respectively to control the flow direction and flow rate of each pipe section of the entire system.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. The preparation system of the present invention pumps the required process water into the chelating agent dilution tank through a pump according to the required concentration of the chelating agent solution, pumps the required chelating agent stock solution into the chelating agent dilution tank through a transfer pump according to the concentration ratio, stirs the mixed liquid for a certain time through the transfer pump, and completes the preparation of the chelating agent solution.

[0035] 2. Through special pipeline arrangements, the present invention can not only implement a method for preparing a chelating agent solution by a pipeline circulation mixing method that requires no stirring and no storage, but also, through the distribution and flow control of each pipeline, implement an on-line concentration adjustment method. By controlling the flowmeter with a controller to gradually reduce the flow rate of the 1# pipeline or the 2# pipeline, the concentration change curve gradually approaches the standard concentration horizontal line, and finally a noise reduction curve that infinitely approaches the standard concentration horizontal line is formed. When the error of the concentration fluctuation ≤ 2% of the standard concentration, it can be considered that the standard concentration is reached;

[0036] 3. The on-line concentration adjustment method of the present invention is rapid and sensitive. During the adjustment process, the liquid in the chelating agent dilution tank continuously circulates along the 4# circulation pipeline, realizing a process of feeding and circulating mixing at the same time. That is, whether it is during feeding, the preparation process, or the concentration adjustment process, the system in the chelating agent dilution tank is always circulating without stopping, completely eliminating the risk of deposition or pipeline blockage caused by the static state of the chelating agent solution.

[0037] 4. In summary, compared with the existing conventional preparation system, the present invention reduces the chelating agent solution stirrer and the solution storage tank, reducing the failure points; the preparation process is simple and easy to operate; the structure is simple and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flowchart (placed horizontally) of a chelating agent solution preparation process applied to a fly ash solidification system proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0040] Referring to Figure 1 , a chelating agent solution preparation process applied to a fly ash solidification system includes the following steps:

[0041] 1) Pipeline arrangement:

[0042] A 2# pipeline is provided at the top of the chelating agent dilution tank for connecting to the main process water pipeline. The 2# pipeline is provided with a 2# switching valve and a supporting flowmeter for controlling the water inlet flow rate;

[0043] A 4# circulation pipeline is set from the bottom to the top of the chelating agent dilution tank, which is used to circulate the liquid system from the bottom to the liquid level at the top of the tank. The 4# circulation pipeline is provided with a detection pipe section and a 4# switch valve. The two detection pipe sections are connected in parallel and are used as spares for each other. Any one of the detection pipe sections is provided with a delivery pump and a sampling detection branch pipe. Any one of the detection pipe sections is also opened or closed through an electromagnetic valve. The delivery pump of the 4# circulation pipeline is provided with a controller, which is used to control the power and delivery flow of the delivery pump. The sampling detection branch pipe is used to detect the concentration and viscosity in the pipeline to judge whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal;

[0044] A 1# pipeline is led out between the pipe orifice near the bottom of the chelating agent dilution tank and the detection pipe section, which is used to connect to the bottom of the chelating agent stock solution tank. The 1# pipeline is successively provided with a delivery pump, a manual valve and a flow control pipe section. The flow control pipe section is opened or closed by two electromagnetic valves, and is internally provided with a 1# switch valve and a supporting flow meter. The flow control pipe section is connected in parallel with a maintenance standby pipe end, which is used to supply the chelating agent stock solution to the chelating agent dilution tank through the delivery pump when the inside of the flow control pipe section and its equipment need to be maintained. Check valves are respectively arranged at both ends of the flow control pipe section to prevent the liquid in the 4# circulation pipeline from flowing back into the 1# pipeline;

[0045] A 3# pipeline is led out between the detection pipe section and the 4# switch valve, which is used to connect to the top of the water weighing and metering tank. The 3# pipeline is provided with a 3# switch valve, which is used to control the introduction of the chelating agent solution into the water weighing and metering tank for weighing;

[0046] The bottom of the water weighing and metering tank is connected to the mixer through a pipeline, and an electromagnetic valve, a switch valve and a booster pump are also arranged in the pipeline, which are used to control the flow and pressure of the chelating agent solution to facilitate fly ash solidification treatment;

[0047] 2) Initial water addition:

[0048] Open the 2# switch valve to make water enter the inlet of the chelating agent dilution tank, and control the water volume to reach the required chelating agent concentration through the liquid level control, and then close the 2# switch valve;

[0049] 3) First addition of chelating agent stock solution:

[0050] Close the 3# switch valve, open the 4# switch valve, open one of the detection pipe sections, open the 1# switch valve and the delivery pump in the 1# pipeline, and close the electromagnetic valve near the pipe orifice at the bottom of the chelating agent dilution tank, so that the chelating agent stock solution enters the top of the chelating agent dilution tank through the detection pipe section and the 4# switch valve and enters the chelating agent dilution tank from above the water surface;

[0051] 4) Initial stirring:

[0052] Interlock the flowmeter to control the inflow of the chelating agent stock solution, achieve the required dosage of the chelating agent at the desired concentration, close the 1# switch valve and the transfer pump in the 1# pipeline, open the solenoid valve near the pipe orifice at the bottom of the chelating agent dilution tank, and let the liquid in the chelating agent dilution tank pass through the 4# circulation pipeline. Continuously operate for 5 - 10 minutes, and use the sampling and detection branch pipe to detect the concentration and viscosity in the pipeline to determine whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal;

[0053] 5) On-line concentration adjustment:

[0054] When the concentration is too low, open the 1# switch valve and the transfer pump in the 1# pipeline for temporary liquid addition. If the concentration is too high, open the 2# switch valve for water addition. Observe the concentration change curve and compare it with the standard concentration horizontal line. Control the flowmeter through the controller to gradually reduce the flow rate of the 1# pipeline or the 2# pipeline, so that the concentration change curve gradually approaches the standard concentration horizontal line, and finally form a noise reduction curve that infinitely approaches the standard concentration horizontal line. When the error of the concentration fluctuation ≤ 2% of the standard concentration, it can be considered that the standard concentration is reached;

[0055] 6) Initial use:

[0056] When the concentration and viscosity change curves tend to be stable and both the concentration and viscosity meet the usage requirements, it proves that the preparation of the chelating agent solution is completed. Then, open the 3# switch valve and close the 4# switch valve, so that the chelating agent solution passes through weighing and pressurization in sequence and is pumped into the mixer for fly ash solidification operation;

[0057] 7) Supplementary preparation of the chelating agent solution:

[0058] During the time when the chelating agent solution is being weighed and used for fly ash solidification, supplement and prepare the chelating agent solution, that is, close the 3# switch valve, open the 2# switch valve, 4# switch valve, 1# switch valve and the transfer pump in the 1# pipeline, open the solenoid valve near the pipe orifice at the bottom of the chelating agent dilution tank, and control the flow rate of the transfer pump in the detection pipe section through the controller to be 2 - 3 times the flow rate of the transfer pump in the 1# pipeline, so that the newly added chelating agent stock solution and the chelating agent solution coming out from the bottom of the chelating agent dilution tank are mixed and flow together, and pass through the detection pipe section and the 4# switch valve, and the newly added process water is put into the upper part of the liquid level of the chelating agent dilution tank for feeding and circulating mixing at the same time;

[0059] 8) Repeated use of the chelating agent solution:

[0060] Repeat step 5) so that the error of the concentration fluctuation on the concentration curve in the detection pipe section ≤ 2% of the standard concentration, and it can be considered that the standard concentration is reached. At this time, completely close the 2# switch valve, 4# switch valve and the 1# switch valve and the transfer pump in the 1# pipeline, open the 3# switch valve, so that the chelating agent solution is re-supplemented into the water weighing metering tank, weighed and pressurized and pumped into the mixer for a new round of fly ash solidification operation.

[0061] For example, illustrate how the concentration change curve becomes a noise reduction curve that infinitely approaches the standard concentration horizontal line:

[0062] 1. Approximate by the bisection method. As in step 5), when the initial concentration is 10% higher than the standard concentration, at this time, add water through the 2# switching valve until the detected concentration is 5% lower than the standard concentration, and immediately close the 2# switching valve (due to the lag of the detected concentration and water addition, the actual water addition may reduce the concentration in the entire circulation system to about 6% lower than the standard concentration);

[0063] 2. Open the 1# switching valve to add the stock solution. When the detected concentration is 2.5% higher than the standard concentration, immediately close the 1# switching valve;

[0064] 3. Open the 2# switching valve to add water, and make the water flow rate half of that in the first step. When the detected concentration is 1.25% lower than the standard concentration, immediately close the 2# switching valve;

[0065] 4. Open the 1# switching valve to add the stock solution, and make the stock solution flow rate half of that in the second step. When the detected concentration is 0.625% higher than the standard concentration, due to the lag of the detected concentration and stock solution addition, the actual concentration in the entire circulation system may be 0.625 ± 1% lower than the standard concentration. Within the 2% concentration error range, it also conforms to the actual concentration fluctuation range of the chelating agent solution, and both can be considered as the effective solidification concentration.

[0066] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent replacements or changes, and should be covered within the protection scope of the present invention.

Claims

1. A preparation process of a chelating agent solution applied to a fly ash solidification system, characterized in that, It includes the following steps: 1) Pipeline layout: There is a #2 pipeline at the top of the chelating agent dilution tank, which is used to connect to the main process water pipe. The #2 pipeline is equipped with a #2 switch valve and a supporting flow meter to control the water inlet flow rate; A #4 circulation pipeline is arranged from the bottom to the top of the chelating agent dilution tank to circulate the liquid system from the bottom to the top liquid level of the mixing tank. The #4 circulation pipeline is provided with a detection pipe section and a #4 switch valve. The two detection pipe sections are connected in parallel and are used as spares for each other. Any one of the detection pipe sections is provided with a delivery pump and a sampling and detection branch pipe. Any one of the detection pipe sections is also opened or closed through a solenoid valve. The delivery pump of the #4 circulation pipeline is provided with a controller to control the power and delivery flow rate of the delivery pump. The sampling and detection branch pipe is used to detect the concentration and viscosity in the pipeline to judge whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal; A #1 pipeline is led out between the pipe orifice near the bottom of the chelating agent dilution tank and the detection pipe section and is used to connect to the bottom of the chelating agent stock solution tank. The #1 pipeline is successively provided with a delivery pump, a manual valve and a flow control pipe section. The flow control pipe section is opened or closed by two solenoid valves and is internally provided with a #1 switch valve and a supporting flow meter. The flow control pipe section is connected in parallel with a maintenance standby pipe end, which is used to supply the chelating agent stock solution to the chelating agent dilution tank through the delivery pump when the inside of the flow control pipe section and its equipment need to be maintained. Check valves are respectively arranged at both ends of the flow control pipe section to prevent the liquid in the #4 circulation pipeline from flowing back into the #1 pipeline; A #3 pipeline is led out between the detection pipe section and the #4 switch valve and is used to connect to the top of the water weighing and metering tank. The #3 pipeline is provided with a #3 switch valve to control the introduction of the chelating agent solution into the water weighing and metering tank for weighing; The bottom of the water weighing and metering tank is connected to the mixer through a pipeline, and a solenoid valve, a switch valve and a booster pump are also arranged in the pipeline to control the flow rate and pressure of the chelating agent solution, which is convenient for fly ash solidification treatment; 2) Initial water addition: Open the #2 switch valve to allow water to enter the inlet of the chelating agent dilution tank, and reach the water volume required for the desired chelating agent concentration through level control, then close the #2 switch valve; 3) First addition of chelating agent stock solution: Close the #3 switch valve, open the #4 switch valve, open one of the detection pipe sections, open the #1 switch valve and the delivery pump in the #1 pipeline, and close the solenoid valve near the pipe orifice at the bottom of the chelating agent dilution tank, so that the chelating agent stock solution enters the top of the chelating agent dilution tank through the detection pipe section and the #4 switch valve and enters the chelating agent dilution tank from above the water surface; 4) Initial stirring: Control the inlet amount of the chelating agent stock solution through flow meter interlock to reach the chelating agent amount required for the desired chelating agent concentration. Close the #1 switch valve and the delivery pump in the #1 pipeline, open the solenoid valve near the pipe orifice at the bottom of the chelating agent dilution tank, so that the liquid in the chelating agent dilution tank passes through the #4 circulation pipeline and continuously runs for 5 - 10 minutes. The sampling and detection branch pipe is used to detect the concentration and viscosity in the pipeline to judge whether the concentration in the pipeline meets the standard and whether the viscosity is abnormal; 5) Online concentration adjustment: When the concentration is too low, open the 1# on-off valve and the transfer pump in the 1# pipeline for temporary liquid addition. If the concentration is too high, open the 2# on-off valve for water addition. Observe the concentration change curve and compare it with the standard concentration horizontal line. Control the flowmeter through the controller to gradually reduce the flow rate of the 1# pipeline or the 2# pipeline, so that the concentration change curve gradually approaches the standard concentration horizontal line, and finally form a noise reduction curve that infinitely approaches the standard concentration horizontal line. When the error of the concentration fluctuation ≤ 2% of the standard concentration, it can be considered that the standard concentration is reached; 6) Initial use: When the concentration and viscosity change curves tend to be stable and both the concentration and viscosity meet the usage requirements, it proves that the chelating agent solution preparation is completed. Then, open the 3# on-off valve and close the 4# on-off valve, so that the chelating agent solution passes through weighing and is pressurized and pumped into the mixer for fly ash solidification operation; 7) Chelating agent solution supplementary preparation: During the time when the chelating agent solution is being weighed and fly ash is being solidified, prepare the chelating agent solution supplement, that is, close the 3# on-off valve, open the 2# on-off valve, the 4# on-off valve, the 1# on-off valve and the transfer pump in the 1# pipeline, open the solenoid valve near the nozzle at the bottom of the chelating agent dilution tank, and control the delivery flow rate of the transfer pump in the detection pipe section through the controller to be 2 - 3 times the delivery flow rate of the transfer pump in the 1# pipeline, so that the newly added chelating agent stock solution and the chelating agent solution coming out from the bottom of the chelating agent dilution tank are mixed and flow together, and pass through the detection pipe section and the 4# on-off valve, and the newly added process water is put above the liquid level of the chelating agent dilution tank for cyclic mixing while feeding materials; 8) Reuse of chelating agent solution: Repeat step 5) to make the concentration fluctuation error on the concentration curve in the detection pipe section ≤ 2% of the standard concentration, and it can be considered that the standard concentration is reached. At this time, completely close the 2# on-off valve, the 4# on-off valve, the 1# on-off valve and the transfer pump in the 1# pipeline, open the 3# on-off valve, so that the chelating agent solution is re-supplemented to the water weighing metering tank, weighed and pressurized and pumped into the mixer for a new round of fly ash solidification operation.

2. The preparation process of a chelating agent solution applied to a fly ash solidification system according to claim 1, characterized in that, A drain pipe is provided at the bottom of the chelating agent dilution tank, which is used to drain the chelating agent solution that has not been used for a long time during major repairs to prevent pipeline blockage caused by sedimentation at the bottom of the tank, or for the wastewater for cleaning the tank body.

3. The preparation process of a chelating agent solution applied to a fly ash solidification system according to claim 1, characterized in that, A drain pipe is provided at the bottom of the chelating agent stock solution tank, which is used to drain the chelating agent stock solution that has not been used for a long time during major repairs to prevent pipeline blockage caused by sedimentation at the bottom of the tank, or for the wastewater for cleaning the tank body.

4. The preparation process of a chelating agent solution applied to a fly ash solidification system according to claim 1, characterized in that, Liquid level gauges are provided on the sides of the chelating agent dilution tank and the chelating agent stock solution tank, which are used to observe the liquid level.

5. The preparation process of a chelating agent solution applied to a fly ash solidification system according to claim 1, characterized in that, A thermometer, a pH meter, a concentration meter and a viscometer are provided in the sampling and detection branch pipe, which are used to comprehensively determine the state of the liquid in the detection pipeline and feedback it to the controller.

6. The preparation process of a chelating agent solution applied to a fly ash solidification system according to claim 1, characterized in that, The transfer pump of the 4# circulation pipeline is provided with a controller, which is respectively connected to each solenoid valve, each on-off valve, each flowmeter, the booster pump and the transfer pump through leg wires, and is used to control the flow direction and flow rate of each pipe section of the entire system.

Images