Multifunctional fgd wet desulfurization simulation dosing device and method

Abstract

The present application relates to a kind of multifunctional FGD wet desulfurization simulation dosing device and method, the device is used as absorption reaction container with measuring cylinder, and limestone slurry in measuring cylinder is maintained to constant temperature state by constant temperature water bath stirring device, and oxidation fan, slurry circulating pump and standard gas bottle are connected on measuring cylinder to simulate the process that absorption tower circulating flow absorbs sulfur dioxide in flue gas in actual production process, the device is simple in structure, easy to operate, can provide valuable test data for actual production process;The defoaming agent dropping device of the multifunctional FGD wet desulfurization simulation dosing device is used for automatically quantifying and dropping defoaming agent into measuring cylinder, and the pressure sensor at the scale 700mL of measuring cylinder, the pressure sensor at the scale 900mL of measuring cylinder, so that slurry foaming process and defoaming agent dropping process are integrated, the strength of slurry foaming capacity and defoaming agent defoaming capacity can be directly tested, the influence caused by human interference factor is reduced, and the accuracy of simulation experiment is high.

Description

Technical Field

[0001] This invention relates to the field of simulation experimental devices, and in particular to a multifunctional FGD wet desulfurization simulation dosing device and method. Background Technology

[0002] Currently, coal-fired power generation remains the main form of power generation in my country. The combustion of coal produces large amounts of SO2 and NO. x And air pollutants such as dust, specifically the SO2 produced,

[0003] Most power plants in my country use wet desulfurization (FGD). Among wet FGD technologies, wet FGD is the most widely used. It utilizes limestone slurry as the desulfurization adsorbent, where CaCO3 reacts counter-currently with SO2 in the flue gas within the absorption tower to generate CaSO3. This CaSO3 is then oxidized by oxygen blown in by a blower, ultimately producing CaSO4·2H2O, thus removing SO2 from the flue gas. Foaming of the absorber slurry is a common problem in wet FGD FGD, which can adversely affect power plant operation, such as reduced desulfurization efficiency and corrosion of the flue gas structure, and in severe cases, may lead to unit outages. Current research on slurry foaming mostly focuses on post-foaming problem solutions, lacking analysis of the foaming process itself. Adding defoamers is a common method for power plants to eliminate slurry foaming, but precise quantification is difficult to achieve in actual application. Generally, small amounts are added multiple times, with further additions determined based on the foam reduction situation. The foaming ability and stability of a solution are related not only to the physical or chemical properties of the solute in the solution, but also to the detection and evaluation methods. There are many methods for measuring foam, including traditional methods such as the airflow method and the pouring method, and newer methods such as the conductivity method and the optical method. However, actual operation detection is quite complex and is limited by various factors. Therefore, there is an urgent need for a reasonable and directly observable device to simulate desulfurization operation.

[0004] Furthermore, the quality of gypsum by-products in wet FGD systems has become an important design guarantee value and a crucial parameter for the operation and control of FGD systems. The quality of desulfurized gypsum directly affects the sales price of gypsum and thus the economic benefits of power plants. Ensuring the quality of desulfurized gypsum requires measures taken from both design and operation management perspectives. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a multifunctional FGD wet desulfurization simulation dosing device and method.

[0006] The technical solution of the present invention is: a multifunctional FGD wet desulfurization simulation dosing device, including a measuring cylinder, a standard gas bottle, a constant temperature water bath stirring device, and a defoamer dripping device; the measuring cylinder is placed inside the constant temperature water bath stirring device, the stirring rotor of the device is placed at the bottom of the measuring cylinder, an oxidation fan is provided on one side of the constant temperature water bath stirring device, and a gas pipe connected to the outlet of the oxidation fan passes through the lower side wall of the measuring cylinder and extends laterally into the measuring cylinder. Several air jets are opened on the side wall of the gas pipe extending into the measuring cylinder. A slurry circulation pump is provided on the other side of the constant temperature water bath stirring device. Slurry pipe A connected to the inlet of the slurry circulation pump is connected to the lower part of the measuring cylinder, and slurry pipe B connected to the outlet of the slurry circulation pump extends laterally into the upper part of the measuring cylinder. Several slurry nozzles are provided on the side wall of slurry pipe B extending into the measuring cylinder.

[0007] The standard gas pipe connected to the outlet of the standard gas cylinder extends vertically into the measuring cylinder. The lower end of the standard gas pipe is located in the middle of the measuring cylinder, and a diffusion device is connected to the lower end of the standard gas pipe. A rotor flow meter and a pressure divider valve are installed on the standard gas pipe. A liquid inlet branch pipe is provided on one side of the upper part of the measuring cylinder, and the drip outlet of the defoamer dripping device corresponds to the upper end of the liquid inlet branch pipe.

[0008] Preferably, the defoamer dripping device includes a base, a storage tank, and a dispensing pump. The storage tank is installed in a receiving groove at the upper end of the base. The upper end of the storage tank is provided with a dispensing chamber. The lower end of the dispensing chamber is provided with a suction tube that extends into the bottom of the storage tank. The dispensing pump is connected to the upper port of the dispensing chamber. A dripping tube is connected to the outlet at the lower part of the dispensing chamber. The outlet of the dripping tube is located at the upper port of the inlet branch pipe.

[0009] Preferably, the graduated cylinder is provided with a measuring scale, a pressure sensor A is provided at the 700mL scale, a pressure sensor B is provided at the 900mL scale, and a pH meter is provided at the bottom of the graduated cylinder.

[0010] Preferably, the dosing device is connected to a computer, the controller of the liquid dispensing pump is connected to the computer via a wire, and the pH meter, pressure sensor A, and pressure sensor B are connected to the computer via signal lines.

[0011] Preferably, both pressure sensor A and pressure sensor B have a baffle at their upper ends.

[0012] A method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device includes the following steps:

[0013] (1) Add 500 mL of limestone slurry to the measuring cylinder, turn on the constant temperature water bath stirring device and set the water bath temperature to 50℃ and the stirring speed to 500 r / min;

[0014] (2) After the limestone slurry is heated to a constant temperature, turn on the oxidation blower to introduce oxygen into the limestone slurry, turn on the slurry circulation pump to atomize the limestone slurry from the slurry nozzle to form a circulating slurry, turn on the main valve and pressure valve of the standard gas cylinder, adjust the flow rate of the rotor flow meter to 200 mL / min, discharge a certain concentration of SO2 into the measuring cylinder, and the slurry begins to foam during the reaction to generate CaSO4·2H2O.

[0015] (3) Start timing when the slurry foams to 700 mL, stop timing when the foaming reaches 900 mL and obtain the time t1, then turn off the oxidation blower, slurry circulation pump and standard gas cylinder;

[0016] (4) The defoamer dripping device uses a pump to draw a certain volume of defoamer into the mixing chamber, and then enters the measuring cylinder through the dripping tube to start defoaming. The interval is 2 minutes, the dosing speed is set to 1 mL / min, and 2 mL is added each time. When the foam drops from 900 mL to 700 mL, the dosing is stopped and the time t2 of the drop process is calculated.

[0017] (5) The strength of the foaming ability of the slurry is judged by t1. The smaller t1 is, the stronger the foaming ability is, and the larger t1 is, the weaker the foaming ability is. The strength of the defoaming performance of the defoamer is judged by t2. The smaller t2 is, the stronger the defoaming ability is, and the larger t2 is, the weaker the defoaming ability is.

[0018] Preferably, the time t1 in step (3) is automatically completed by pressure sensor A, pressure sensor B and computer. When the slurry foams to pressure sensor A, pressure sensor A gives a pressure signal and the computer starts to time automatically. When the slurry foams to pressure sensor B, pressure sensor B gives a pressure signal and the computer stops timing and automatically obtains the time t1. The time t2 in step (4) is automatically obtained in the same way as in step (3).

[0019] The beneficial technical effects of this invention are:

[0020] (1) The multifunctional FGD wet desulfurization simulation dosing device uses a graduated cylinder as an absorption reaction vessel and maintains the limestone slurry in the graduated cylinder at a constant temperature through a constant temperature water bath stirring device. An oxidation blower, a slurry circulation pump and a standard gas cylinder are connected to the graduated cylinder to simulate the process of the absorption tower circulating and absorbing sulfur dioxide in the flue gas during actual production. The device has a simple structure and is easy to operate, and can provide valuable experimental data for actual production processes.

[0021] (2) The defoamer dripping device of the multifunctional FGD wet desulfurization simulation dosing device is used to automatically and quantitatively add defoamer in the measuring cylinder. Combined with the pressure sensor at 700mL and 900mL of the measuring cylinder, the foaming process of the slurry is integrated with the defoamer dripping process. The foaming ability of the slurry and the defoaming performance of the defoamer can be directly tested, reducing the influence of human interference factors and the accuracy of the simulation experiment is high.

[0022] (3) The simulation experiment method automatically calculates the interval foaming time of limestone slurry in the graduated cylinder by using pressure sensors at 700mL and 900mL of graduated cylinder, and then judges the strength of the foaming ability of limestone slurry. Defoamer is added to graduated cylinder at intervals and in quantitative amounts by defoamer dripping device. The interval defoaming time of foam in graduated cylinder is automatically calculated by two pressure sensors, and then the strength of the defoaming ability of defoamer is judged. According to the simulation experiment, the air intake of oxidation blower, the circulation speed of slurry circulation pump and the constant temperature stirring parameters of constant temperature water bath stirring device can be adjusted accordingly in actual production process to improve desulfurization effect and desulfurization efficiency and ensure the smooth operation of power plant units. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 yes Figure 1 A partial view within the image.

[0025] In the diagram, 11. Measuring cylinder, 111. Liquid inlet branch pipe, 12. Standard gas cylinder, 121. Standard gas pipeline, 122. Diffusion device, 123. Rotor flow meter, 124. Pressure divider valve, 13. Constant temperature water bath stirring device, 131. Stirring rotor, 14. Defoamer dripping device, 141. Base, 142. Drug storage tank, 143. Liquid dispensing pump, 144. Drug dripping pipe, 145. Support, 146. Shut-off valve, 147. Liquid dispensing chamber, 148. Drug suction pipe, 15. Oxidation blower, 151. Gas pipeline, 152. Jet nozzle, 16. Slurry circulation pump, 161. Slurry pipeline A, 162. Slurry pipeline B, 163. Slurry nozzle, 17. Pressure sensor A, 18. Pressure sensor B, 19. pH meter, 20. Computer, 201. Wire, 202. Signal line, 21. Baffle. Detailed Implementation

[0026] Example 1, referring to Figures 1-2 in the specification, describes a multifunctional FGD wet desulfurization simulation dosing device, including a measuring cylinder, a standard gas cylinder, a constant temperature water bath stirring device, and an antifoaming agent dripping device. The measuring cylinder is placed inside the constant temperature water bath stirring device, with its magnetic stirring rotor positioned at the bottom of the cylinder. The stirring rotor stirs the limestone slurry inside the measuring cylinder, simultaneously heating it for faster temperature rise. An oxidation fan is installed on one side of the constant temperature water bath stirring device, and a gas pipe connected to the outlet of the oxidation fan extends laterally through the lower side wall of the measuring cylinder into the... Inside the graduated cylinder, several air jets are opened on the side wall of the gas pipe extending into the graduated cylinder. Oxygen is evenly injected into the graduated cylinder through each air jet. On the other side of the constant temperature water bath stirring device, there is a slurry circulation pump. The slurry pipe A connected to the inlet of the slurry circulation pump is connected to the lower part of the graduated cylinder. The slurry pipe B connected to the outlet of the slurry circulation pump extends horizontally into the upper part of the graduated cylinder. Several slurry nozzles are provided on the side wall of the slurry pipe B extending into the graduated cylinder. The limestone slurry at the bottom of the graduated cylinder is transported to the upper end through the slurry circulation pump and atomized and sprayed out from the slurry nozzles to form a slurry circulation.

[0027] A standard gas pipeline connected to the outlet of the standard gas cylinder extends vertically into the measuring cylinder. The lower end of the standard gas pipeline is located in the middle of the measuring cylinder, and a diffusion device is connected to the lower end of the standard gas pipeline. The diffusion device evenly diffuses the standard gas into the measuring cylinder. A rotor flow meter and a pressure valve are installed on the standard gas pipeline, and the flow rate of the standard gas is adjusted by the rotor flow meter. A liquid inlet branch pipe is provided on one side of the upper part of the measuring cylinder. The drip outlet of the defoamer dripping device corresponds to the upper end of the liquid inlet branch pipe. The liquid inlet branch pipe is set to drip the defoamer from one side of the measuring cylinder to avoid interference from the slurry pipeline and the diffusion device.

[0028] The defoamer dripping device includes a base, a storage tank, and a dispensing pump. The storage tank is installed in a receiving groove at the upper end of the base. The upper end of the storage tank is provided with a dispensing chamber, and the lower end of the dispensing chamber is provided with a suction tube that extends into the bottom of the storage tank. The dispensing pump is connected to the upper port of the dispensing chamber. The outlet of the dispensing chamber is connected to a dripping tube, and the outlet of the dripping tube is located at the upper port of the inlet branch pipe. The middle part of the dripping tube is provided with a support, and a shut-off valve is provided on the dripping tube. The defoamer is drawn into the dispensing chamber by the dispensing pump and then discharged from the dripping tube. Intermittent dosing is achieved by intermittently starting and stopping the dispensing pump.

[0029] The graduated cylinder is equipped with a measuring scale. Pressure sensor A is located at the 700mL mark, and pressure sensor B is located at the 900mL mark. The two sensors are used to detect the foaming level of the slurry and give a signal. A pH meter is located at the bottom of the graduated cylinder to measure the pH value of the limestone slurry in real time.

[0030] The dosing device is connected to a computer, and the controller of the liquid preparation pump is connected to the computer via wires. The pH meter, pressure sensor A, and pressure sensor B are connected to the computer via signal lines. Each of the pressure sensors A and B has a baffle at its upper end, which covers the pressure sensor to prevent standard gas or atomized limestone slurry from interfering with the pressure sensor.

[0031] Example 2, see appendix to the instruction manual. Figure 1-2 A method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device includes the following steps:

[0032] (1) Add 500 mL of limestone slurry to the measuring cylinder, turn on the constant temperature water bath stirring device and set the water bath temperature to 50℃ and the stirring speed to 500 r / min;

[0033] (2) After the limestone slurry is heated to a constant temperature, turn on the oxidation blower to introduce oxygen into the limestone slurry, turn on the slurry circulation pump to atomize the limestone slurry from the slurry nozzle to form a circulating slurry, turn on the main valve and pressure valve of the standard gas cylinder, adjust the flow rate of the rotor flow meter to 200 mL / min, discharge a certain concentration of SO2 into the measuring cylinder, and the slurry begins to foam during the reaction to generate CaSO4·2H2O.

[0034] (3) Start timing when the slurry foams to 700 mL, stop timing when the foaming reaches 900 mL and obtain the time t1, then turn off the oxidation blower, slurry circulation pump and standard gas cylinder;

[0035] (4) The defoamer dripping device uses a pump to draw a certain volume of defoamer into the mixing chamber, and then enters the measuring cylinder through the dripping tube to start defoaming. The interval is 2 minutes, the dosing speed is set to 1 mL / min, and 2 mL is added each time. When the foam drops from 900 mL to 700 mL, the dosing is stopped and the time t2 of the drop process is calculated.

[0036] (5) The strength of the foaming ability of the slurry is judged by t1. The smaller t1 is, the stronger the foaming ability is, and the larger t1 is, the weaker the foaming ability is. The strength of the defoaming performance of the defoamer is judged by t2. The smaller t2 is, the stronger the defoaming ability is, and the larger t2 is, the weaker the defoaming ability is.

[0037] The time t1 in step (3) is automatically completed by pressure sensor A, pressure sensor B and computer. When the slurry foams to 700mL (pressure sensor A), pressure sensor A gives a pressure signal and the computer starts to start timing automatically. When the foam foams to 900mL (pressure sensor B), pressure sensor B gives a pressure signal and the computer stops timing and automatically obtains the time t1. The time t2 in step (4) is automatically obtained in the same way as in step (3) to realize automated control.

[0038] Multiple standard gas cylinders can be set up simultaneously, each with a different SO2 concentration, forming a concentration of 2000 mg / m³. 3 2500mg / m 3 3000mg / m 3 3500mg / m 3 Due to the concentration gradient, the difference in sulfur content in the coal and the different loads of the unit, the sulfur content in the flue gas entering the desulfurization tower is also different. Therefore, standard gases of different concentrations are set up to conduct desulfurization simulation experiments at different concentrations.

[0039] Example 3, see appendix to the instruction manual. Figure 1-2 A method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device includes the following steps:

[0040] (1) Add 500 mL of limestone slurry to the measuring cylinder, turn on the constant temperature water bath stirring device and set the water bath temperature to 50℃ and the stirring speed to 500 r / min;

[0041] (2) After the limestone slurry is heated to a constant temperature, turn on the oxidation blower to introduce oxygen into the limestone slurry, and turn on the slurry circulation pump to atomize and spray the limestone slurry from the slurry nozzle to form a circulating slurry.

[0042] (3) Set up multiple standard gas cylinders, each with a different SO2 concentration, 2000 mg / m³. 3 3000mg / m 3 4000mg / m 3 5000mg / m 3 The concentration gradient was determined by sequentially introducing standard gases of different concentrations into the graduated cylinder at a flow rate of 200 mL / min using a rotor flow meter. Each time the standard gas cylinder was replaced, the limestone slurry was replaced accordingly.

[0043] (4) Run continuously for 1 hour at each SO2 concentration, record the continuous change value of pH value within 1 hour, analyze the effect of different SO2 flue gas concentrations on the pH value of slurry, calculate the content of CaSO3.1 / 2H2O and CaSO4.2H2O in slurry when running at different SO2 concentrations, and judge the quality of gypsum.

[0044] Example 4, see appendix to the instruction manual. Figure 1-2 A method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device is described. The experimental method in this embodiment is basically the same as that in Embodiment 3, except that only one standard gas cylinder is set up with an SO2 concentration of 30 mg / m³. 3The stirring speed of the constant temperature water bath mixer was set to 200 r / min, 400 r / min, 600 r / min, and 800 r / min in sequence. The mixer was run continuously for 1 hour at each stirring speed. The contents of CaSO3·1 / 2H2O and CaSO4·2H2O in the gypsum slurry at each stirring speed were analyzed to determine the effect of different stirring speeds on the gypsum slurry.

[0045] Example 5, see appendix to the instruction manual. Figure 1-2 A method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device is described. The experimental method in this embodiment is basically the same as that in Embodiment 3, except that only one standard gas cylinder is set up with an SO2 concentration of 30 mg / m³. 3 The stirring speed of the warm water bath mixing device was set to 500 r / min. Then, the speed of the oxidation blower was adjusted to 100 r / min, 200 r / min, 300 r / min, 400 r / min, and 500 r / min in sequence. The device was run continuously for 1 hour at each speed. The contents of CaSO3·1 / 2H2O and CaSO4·2H2O in the gypsum slurry at each speed were analyzed to determine the effect of the oxygen intake of the oxidation blower on the gypsum slurry.

Claims

1. A multifunctional FGD wet desulfurization simulation dosing device, characterized in that: Includes graduated cylinders, standard gas bottles, constant temperature water bath stirring device, and defoamer dripping device; The graduated cylinder is placed inside a constant temperature water bath stirring device. The stirring rotor of the device is placed at the bottom of the graduated cylinder. An oxidation fan is installed on one side of the constant temperature water bath stirring device. The gas pipe connected to the outlet of the oxidation fan passes through the lower side wall of the graduated cylinder and extends laterally into the graduated cylinder. Several air jets are opened on the side wall of the gas pipe extending into the graduated cylinder. A slurry circulation pump is installed on the other side of the constant temperature water bath stirring device. Slurry pipe A connected to the inlet of the slurry circulation pump is connected to the lower part of the graduated cylinder. Slurry pipe B connected to the outlet of the slurry circulation pump extends laterally into the upper part of the graduated cylinder. Several slurry nozzles are provided on the side wall of slurry pipe B extending into the graduated cylinder. The standard gas pipe connected to the outlet of the standard gas cylinder extends vertically into the measuring cylinder. The lower end of the standard gas pipe is located in the middle of the measuring cylinder, and a diffusion device is connected to the lower end of the standard gas pipe. A rotor flow meter and a pressure divider valve are installed on the standard gas pipe. A liquid inlet branch pipe is provided on one side of the upper part of the measuring cylinder, and the drip outlet of the defoamer dripping device corresponds to the upper end of the liquid inlet branch pipe. The defoamer dripping device includes a base, a storage tank, and a dispensing pump. The storage tank is installed in a receiving groove at the upper end of the base. The upper end of the storage tank is provided with a dispensing chamber. The lower end of the dispensing chamber is provided with a suction tube that extends into the bottom of the storage tank. The dispensing pump is connected to the upper port of the dispensing chamber. The outlet at the lower part of the dispensing chamber is connected to a dripping tube. The outlet of the dripping tube is located at the upper port of the inlet branch pipe. The graduated cylinder is equipped with a measuring scale, a pressure sensor A is installed at the 700mL scale, a pressure sensor B is installed at the 900mL scale, and a pH meter is installed at the bottom of the graduated cylinder. The dosing device is connected to a computer, the controller of the liquid preparation pump is connected to the computer via wires, and the pH meter, pressure sensor A, and pressure sensor B are connected to the computer via signal lines.

2. The multifunctional FGD wet desulfurization simulation dosing device according to claim 1, characterized in that: Both pressure sensor A and pressure sensor B have baffles at their upper ends.

3. The method for conducting simulation experiments using a multifunctional FGD wet desulfurization simulation dosing device according to claim 2, characterized by the following steps: (1) Add 500 mL of limestone slurry to the measuring cylinder, turn on the constant temperature water bath stirring device and set the water bath temperature to 50℃ and the stirring speed to 500 r / min; (2) After the limestone slurry is heated to a constant temperature, turn on the oxidation blower to introduce oxygen into the limestone slurry, turn on the slurry circulation pump to atomize the limestone slurry from the slurry nozzle to form a circulating slurry, turn on the main valve and pressure valve of the standard gas cylinder, adjust the flow rate of the rotor flow meter to 200 mL / min, discharge a certain concentration of SO2 into the measuring cylinder, and the slurry begins to foam during the reaction to generate CaSO4·2H2O. (3) Start timing when the slurry foams to 700 mL, stop timing when the foaming reaches 900 mL and obtain the time t1, then turn off the oxidation blower, slurry circulation pump and standard gas cylinder; (4) The defoamer dripping device uses a pump to draw a certain volume of defoamer into the mixing chamber, and then enters the measuring cylinder through the dripping tube to start defoaming. The interval is 2 minutes, the dosing speed is set to 1 mL / min, and 2 mL is added each time. When the foam drops from 900 mL to 700 mL, the dosing is stopped and the time t2 of the drop process is calculated. (5) The strength of the foaming ability of the slurry is judged by t1. The smaller t1 is, the stronger the foaming ability is, and the larger t1 is, the weaker the foaming ability is. The strength of the defoaming performance of the defoamer is judged by t2. The smaller t2 is, the stronger the defoaming ability is, and the larger t2 is, the weaker the defoaming ability is. The time t1 in step (3) is automatically completed by pressure sensor A, pressure sensor B and computer. When the slurry foams to pressure sensor A, pressure sensor A gives a pressure signal and the computer starts to time automatically. When the slurry foams to pressure sensor B, pressure sensor B gives a pressure signal and the computer stops timing and automatically obtains the time t1. The time t2 in step (4) is automatically obtained in the same way as in step (3).

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