阅读说明：本技术 一种脱硫浆液中亚硫酸盐浓度在线测量系统及方法 (On-line measuring system and method for concentration of sulfite in desulfurization slurry ) 是由 鲁晓宇 何育东 余昭 房孝维 白永岗 李兴华 陶明 李楠 李明皓 于 2021-08-24 设计创作，主要内容包括：本发明公开了一种脱硫浆液中亚硫酸盐浓度在线测量系统及方法,包括自动控制系统、反应器、浆液计量泵、氧化剂I-(2)液槽、氧化剂I-(2)液注射泵、氧化还原电极、冲洗水喷嘴及废液蠕动泵；氧化剂I-(2)液槽的出口经氧化剂I-(2)液注射泵与反应器的氧化剂I-(2)液入口相连通,浆液循环管路的出口经浆液计量泵与反应器的浆液入口相连通,冲洗水管道与反应器内的冲洗水喷嘴相连通,氧化还原电极插入于反应器内；自动控制系统与浆液计量泵、氧化剂I-(2)液注射泵、氧化还原电极、冲洗水阀及废液蠕动泵,该系统及方法能够准确、自动和实时地测量出脱硫浆液中亚硫酸盐浓度。(The invention discloses an on-line measuring system and method for the concentration of sulfite in desulfurization slurry, which comprises an automatic control system, a reactor, a slurry metering pump and an oxidant I 2 Liquid tank, oxidant I 2 A liquid injection pump, a redox electrode, a washing water nozzle and a waste liquid peristaltic pump; oxidizing agent I 2 The outlet of the liquid tank is through an oxidant I 2 Oxidant I for liquid injection pump and reactor 2 The liquid inlet is communicated, the outlet of the slurry circulating pipeline is communicated with the slurry inlet of the reactor through a slurry metering pump, the flushing water pipeline is communicated with a flushing water nozzle in the reactor, and the redox electrode is inserted into the reactor; automatic control system, slurry metering pump and oxidant I 2 The system and the method can accurately, automatically and real-timely measure the concentration of sulfite in the desulfurization slurry.)

1. The on-line measuring system for the concentration of sulfite in desulfurization slurry is characterized by comprising an automatic control system, a reactor (1), a slurry metering pump (3) and an oxidant I₂A liquid tank (4) and an oxidant I₂A liquid injection pump (5), an oxidation-reduction electrode (6), a washing water nozzle (8) and a waste liquid peristaltic pump (9);

oxidizing agent I₂The outlet of the liquid tank (4) is connected with an oxidant I₂Oxidant I of liquid injection pump (5) and reactor (1)₂The liquid inlet is communicated, the outlet of the slurry circulating pipeline is communicated with the slurry inlet of the reactor (1) through a slurry metering pump (3), a flushing water pipeline is communicated with a flushing water nozzle (8) in the reactor (1), and the redox electrode (6) is inserted into the reactor (1);

automatic control system, slurry metering pump (3) and oxidant I₂A liquid injection pump (5), an oxidation-reduction electrode (6), a flushing water valve (7) and a waste liquid peristaltic pump (9).

2. The on-line measuring system for the concentration of sulfite in desulfurization slurry according to claim 1, wherein a drain valve is provided at the bottom outlet of the reactor (1).

3. The system for on-line measurement of the concentration of sulfite in desulfurization slurry according to claim 1, wherein the bottom outlet of the reactor (1) is communicated with the inlet of a waste liquid peristaltic pump (9).

4. The on-line measuring system for the concentration of sulfite in a desulfurization slurry according to claim 1, wherein the reactor (1) is fixed to a support (2).

5. The system for on-line measurement of the concentration of sulfite in a desulfurization slurry according to claim 1, wherein the rinse water pipe is communicated with a rinse water nozzle 8 in the reactor (1) through a rinse water valve (7).

6. The system of claim 1, wherein the automatic control system is connected to a display.

7. The system of claim 1, wherein the automatic control system is connected to a memory.

8. An online measurement method for the concentration of sulfite in desulfurization slurry, which is characterized in that the online measurement system for the concentration of sulfite in desulfurization slurry based on claim 1 comprises the following steps:

opening a slurry metering pump (3) through an automatic control system, extracting quantitative slurry from a slurry circulating pipeline, inputting the slurry into a reactor (1), and opening an oxidant I₂A liquid injection pump (5) adds I dropwise into the reactor (1)₂Reading the potential value of the oxidation-reduction electrode (6), and stopping adding I when the potential changes in a step manner₂Liquid and metering the consumption I₂Volume of liquid, andaccording to I₂Concentration of the liquor the concentration of sulfite was calculated.

Technical Field

The invention belongs to the technical field of environmental protection and industrial waste gas purification, and relates to an online measuring system and method for the concentration of sulfite in desulfurization slurry.

Background

With the increasing promotion of national atmospheric pollutant emission standards, large coal-fired thermal power generating units generally implement or are implementing the ultralow emission standards of atmospheric pollutants, and the optimal balance point of ultralow emission and unit energy consumption can be expected to be found through operation optimization control while the ultralow emission of flue gas is realized, so that the unit energy consumption is reduced, and the method is the direction of efforts of thermal power enterprises.

The limestone-gypsum wet flue gas desulfurization technique is the most mature and widely applied flue gas desulfurization technique in the prior art. The raw flue gas enters an absorption tower, and SO in the flue gas₂With limestone (CaCO) in the spray slurry₃) Reacting to generate calcium sulfite; the calcium sulfite is oxidized by the oxidizing air to obtain a byproduct gypsum (CaSO)_4·2H₂O) crystals. When the oxidation rate in the slurry is too low, the sulfite content in the slurry is high, which affects the desulfurization efficiency and the quality of the desulfurization by-product gypsum, and when the sulfite content is too high, the system can be scaled to cause blockage, thus endangering the safe operation of the system. In order to ensure the quality of gypsum and prevent desulfurization and scaling, most power plants are supplemented into a slurry tank in a tower by designing the maximum oxidation air quantity, and slurry is always in a peroxide state, so that the operation energy consumption of an oxidation air system is higher. Meanwhile, excessive oxidation air is supplemented into the absorption tower slurry pool, so that the foaming phenomenon of the absorption tower slurry pool tends to be serious, dissolved oxygen of slurry in the tower is increased, and the corrosion risk of equipment and pipelines is aggravated.

At present, manual sampling and laboratory detection of sulfite content in samples are mainly adopted for evaluation of oxidation processes at home and abroad. Compared with the actual situation, the oxidation condition of the slurry tested by the method has larger delay, and in addition, the easy oxidation of the sulfite, the detection result of a laboratory does not completely accord with the actual situation in the slurry. The online monitoring mainly adopts an ORP method, but the ORP can only reflect the relative degree of the oxidation or the reduction of the desulfurization circulating slurry and cannot completely show the concentration of certain oxides or reducing substances in the slurry. The components of the desulfurization circulating slurry are very complex, the ORP index is related to a plurality of factors such as the pH value of the slurry, the valence state of metal ions in the solution and the like, and the single index is difficult to realize the precise and systematic regulation and control of the oxidation degree.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an online measuring system and method for the concentration of sulfite in desulfurization slurry, which can accurately, automatically and real-timely measure the concentration of sulfite in the desulfurization slurry.

In order to achieve the aim, the system for online measuring the concentration of the sulfite in the desulfurization slurry comprises an automatic control system, a reactor, a slurry metering pump and an oxidant I₂Liquid tank, oxidant I₂A liquid injection pump, a redox electrode, a washing water nozzle and a waste liquid peristaltic pump;

oxidizing agent I₂The outlet of the liquid tank is through an oxidant I₂Oxidant I for liquid injection pump and reactor₂The liquid inlet is communicated, the outlet of the slurry circulating pipeline is communicated with the slurry inlet of the reactor through a slurry metering pump, the flushing water pipeline is communicated with a flushing water nozzle in the reactor, and the redox electrode is inserted into the reactor;

automatic control system, slurry metering pump and oxidant I₂A liquid injection pump, an oxidation-reduction electrode, a flushing water valve and a waste liquid peristaltic pump.

A drain valve is arranged at the outlet at the bottom of the reactor.

The bottom outlet of the reactor is communicated with the inlet of a waste liquid peristaltic pump.

The reactor is fixed on the bracket.

The flushing water pipeline is communicated with a flushing water nozzle in the reactor through a flushing water valve.

The automatic control system is connected with a display.

The automatic control system is connected with a memory.

The method for online measuring the concentration of the sulfite in the desulfurization slurry comprises the following steps:

opening the slurry metering pump through the automatic control system, extracting quantitative slurry from the slurry circulating pipeline, inputting the slurry into the reactor, and opening the oxidant I₂Dropwise adding I into the reactor by using a liquid injection pump₂Reading the potential value of the oxidation-reduction electrode, and stopping adding I when the potential changes in a step manner₂Liquid and metering the consumption I₂Volume of liquid, again according to I₂Concentration of the liquor the concentration of sulfite was calculated.

The invention has the following beneficial effects:

the system and the method for on-line measuring the concentration of the sulfite in the desulfurization slurry control the quantitative extraction of the slurry and the addition of the oxidant I through the automatic control system during the specific operation₂Liquid, flushing, measuring, discharging liquid, judging the end point of redox reaction, and precisely metering oxidant I₂The amount of the solution is calculated, and then the concentration of sulfite in the sampled slurry is calculated, so that the decomposition of sulfite samples in the sampling, transportation and laboratory analysis processes is effectively prevented, the analysis accuracy is improved, and compared with the traditional iodometry, the method cancels reagents HCL and Na₂S₂O₃The method reduces the usage amount of reagents, simplifies the operation process and simplifies the system structure.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Wherein, 1 is a reactor, 2 is a bracket, 3 is a serous fluid metering pump, and 4 is an oxidant I₂The liquid tank 5 is an oxidant I₂The liquid injection pump 6 is an oxidation-reduction electrode, the washing water valve 7 is a washing water nozzle 8, and the waste liquid peristaltic pump 9.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the invention. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to FIG. 1, the system for on-line measurement of sulfite concentration in desulfurization slurry comprises a reactor 1, a bracket 2, a slurry metering pump 3 and an oxidant I₂Liquid tank 4 and oxidant I₂The device comprises a liquid injection pump 5, an oxidation-reduction electrode 6, a flushing water valve 7, a flushing water nozzle 8 and a waste liquid peristaltic pump 9;

the reactor 1 is fixed on the bracket 2, a liquid discharge valve is arranged at the bottom outlet of the reactor 1, the bottom outlet of the reactor 1 is communicated with the inlet of a waste liquid peristaltic pump 9, and the oxidant I₂The outlet of the liquid tank 4 is through an oxidant I₂Oxidant I of liquid injection pump 5 and reactor 1₂The liquid inlet is communicated, the outlet of the slurry circulation pipeline is communicated with the slurry inlet of the reactor 1 through the slurry metering pump 3, the flushing water pipeline is communicated with a flushing water nozzle 8 in the reactor 1 through a flushing water valve 7, and the oxidation-reduction electrode 6 is inserted into the reactor 1.

Detection of the slurry with oxidant I by means of the redox electrode 6₂Liquid reactionThe oxidation-reduction potential of the process, an automatic control system, a slurry metering pump 3, an oxidant I2 liquid injection pump 5, an oxidation-reduction electrode 6, a flushing water valve 7 and a waste liquid peristaltic pump 9;

quantitatively extracting slurry and adding oxidant I under the control of an automatic control system₂Liquid, flushing, measuring and discharging, judging the end point of the oxidation-reduction reaction by an automatic control system, and accurately metering and adding an oxidant I₂And (4) automatically calculating the concentration of sulfite in the sampled slurry according to the amount of the liquid, and finally displaying the sulfite through a display and storing the sulfite through a memory.

The working process of the invention is as follows:

opening the slurry metering pump 3, extracting a certain amount of slurry from the slurry circulation pipeline, inputting the slurry into the reactor 1, and opening the oxidant I₂A liquid injection pump 5 adds I dropwise into the reactor 1₂Reading the potential value of the oxidation-reduction electrode 6, and stopping adding I when the potential changes in a step shape₂Liquid and metering the consumption I₂Volume of liquid, again according to I₂Concentration of the liquor the concentration of sulfite was calculated.