阅读说明：本技术 一种亚硫酸钙在线监测系统及方法 (Calcium sulfite online monitoring system and method ) 是由 袁明宇 吴子艳 于 2019-11-15 设计创作，主要内容包括：本发明涉及脱硫吸收塔浆液品质判断技术领域,尤其涉及一种亚硫酸钙在线监测系统及方法,一种亚硫酸钙在线监测系统,包括取样泵、烘烤器、输送机、第一反应器、气液分离器和第二反应器；所述取样泵的入口与吸收塔相连通,所述取样泵的出口与所述烘烤器相连通,所述烘烤器通过所述输送机与所述第一反应器相连通,所述第一反应器通过所述气液分离器与所述第二反应器相连通。该亚硫酸钙在线监测系统全部采用自动化控制,大大简化了操作步骤,降低了检测人员的工作强度,并且使运行人员能够及时了解吸收塔浆液内亚硫酸钙含量,为运行人员调整工况提供了依据。(The invention relates to the technical field of desulfurization absorption tower slurry quality judgment, in particular to a calcium sulfite online monitoring system and a method, wherein the calcium sulfite online monitoring system comprises a sampling pump, a roaster, a conveyor, a first reactor, a gas-liquid separator and a second reactor; the inlet of the sampling pump is communicated with the absorption tower, the outlet of the sampling pump is communicated with the roaster, the roaster is communicated with the first reactor through the conveyor, and the first reactor is communicated with the second reactor through the gas-liquid separator. The calcium sulfite on-line monitoring system is completely automatically controlled, so that the operation steps are greatly simplified, the working strength of detection personnel is reduced, the operation personnel can know the content of calcium sulfite in the slurry of the absorption tower in time, and a basis is provided for the operation personnel to adjust the working condition.)

1. The on-line calcium sulfite monitoring system is characterized by comprising a sampling pump (2), a roaster (3), a conveyor (4), a first reactor (5), a gas-liquid separator (6) and a second reactor (7);

the inlet of the sampling pump (2) is communicated with the absorption tower (1), the outlet of the sampling pump (2) is communicated with the roaster (3), the roaster (3) is communicated with the first reactor (5) through the conveyor (4), and the first reactor (5) is communicated with the second reactor (7) through the gas-liquid separator (6).

2. The monitoring system according to claim 1, further comprising a heating means (8), the heating means (8) being arranged inside the first reactor (5).

3. The monitoring system according to claim 1, further comprising a pH meter (11), the pH meter (11) being detachably arranged on the second reactor (7).

4. A monitoring system according to any one of claims 1-3, characterised in that a first feeder (9) is arranged on the first reactor (5).

5. A monitoring system according to claim 4, characterised in that a second feeder (10) is arranged on the second reactor (7).

6. The calcium sulfite online monitoring method is characterized by comprising the following steps: the sampling pump (2) takes out the slurry from the absorption tower (1) and then sends the slurry into the roaster (3), the conveyor (4) conveys the solid matters dried by the roaster (3) to the first reactor (5), the product in the first reactor (5) is conveyed to the second reactor (7) through the gas-liquid separator (6), and the online monitoring of the calcium sulfite is realized by measuring the consumption of the materials in the second reactor (7).

7. The monitoring method according to claim 6, characterized by comprising the following steps:

s1, taking out the slurry from the absorption tower (1) by a sampling pump (2), conveying the slurry into a roaster (3), and heating and treating at the temperature of 450-650 ℃ until drying to obtain a solid substance;

s2, conveying the solid matter to a first reactor (5) by a conveyor (4), and adding excessive H₃PO₄After the reaction is completed, the heating component (8) is started to obtain SO₂A gas;

s3, adding SO₂The gas is conveyed to the gas-liquid separator (6) containing excessive H₂O₂In the second reactor (7);

s4, after the reaction in the step S3 is completed, dropwise adding NaOH solution into the second reactor (7) until the pH value is 7, and stopping dropwise adding;

s5 the content of calcium sulfite is calculated by measuring the consumption of NaOH.

8. The monitoring method according to claim 6, wherein in step S2, H₃PO₄The concentration of (B) is 0.5-2 mol/L.

9. The monitoring method according to claim 6, wherein in step S2, the heating means (8) is turned on to maintain the temperature in the first reactor (5) at 30-40 ℃.

10. The monitoring method according to claim 6, wherein in step S4, the concentration of NaOH is 0.5-2 mol/L.

Technical Field

The invention relates to the technical field of desulfurization absorption tower slurry quality judgment, in particular to a calcium sulfite online monitoring system and a calcium sulfite online monitoring method.

Background

The desulfurization absorption tower is a measure for absorbing smoke dust and dust by adopting a liquid spraying mode, and further enabling gas purified and discharged into air to meet the requirements of national production environment standards to be operated. However, in this process, the sulfur-containing substances in the gas are often absorbed by alkalization, i.e., hydrogen sulfide gas is converted into calcium sulfate or calcium sulfite. Along with the extension of the absorption time, the content of calcium sulfite in the tower is greatly increased, and the increase of the calcium sulfite can cause the operation condition of the absorption tower to be deteriorated, so that the normal operation is difficult to ensure, and the operation cost of the desulfurization tower is higher.

Therefore, the index of the calcium sulfite must be detected frequently, the quality of the slurry in the absorption tower is judged according to the detection result, and the output condition of the oxidation fan is adjusted. When the content of calcium sulfite is high, the output of the oxidation fan is increased; when the content of calcium sulfite is low, the output of the oxidation fan is reduced, so that the aims of saving energy and reducing consumption are fulfilled.

At present, the determination of calcium sulfite generally adopts an iodometry method, which mainly comprises the following steps: taking a certain amount of absorption tower slurry by using a measuring cup, putting the slurry into a baking oven for drying, putting the dried slurry into a closed container, adding concentrated sulfuric acid into the container to decompose sulfurous acid to generate sulfur dioxide, then dropwise adding excessive standard iodine solution into the closed container to fully oxidize the sulfur dioxide, finally titrating the excessive iodine solution by using a standard sodium thiosulfate solution, using a starch solution as an indicator, and obtaining a titration end point when the color is changed from blue to colorless. And determining the amount of generated sulfur dioxide according to the amount of the standard iodine solution dropwise added and the amount of the standard sodium thiosulfate solution consumed at the titration end point, so as to obtain the content of the calcium sulfite in the slurry. However, the method has long time for detecting the content of the calcium sulfite and complicated operation steps, and operating personnel cannot know the content of the calcium sulfite in the slurry of the absorption tower in time, namely the method cannot provide a basis for the operating personnel to adjust the working condition in time.

Disclosure of Invention

The invention aims to solve the technical problems that the existing calcium sulfite detection method is complicated in operation and long in detection period, and can not provide a basis for operating personnel to adjust the working condition in time.

The technical scheme for solving the technical problems is as follows: a calcium sulfite online monitoring system comprises a sampling pump, a roaster, a conveyor, a first reactor, a gas-liquid separator and a second reactor; the inlet of the sampling pump is communicated with the absorption tower, the outlet of the sampling pump is communicated with the roaster, the roaster is communicated with the first reactor through the conveyor, and the first reactor is communicated with the second reactor through the gas-liquid separator.

The inlet of the sampling pump is communicated with the absorption tower, the outlet of the sampling pump is communicated with the inlet of the roaster, the outlet of the roaster is communicated with the inlet of the conveyor, the outlet of the conveyor is communicated with the inlet of the first reactor, the outlet of the first reactor is communicated with the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is communicated with the inlet of the second reactor. Absorption tower thick liquid passes through the sampling pump, carries a quantitative thick liquid to the roaster, and the temperature in the roaster is higher, can be with the instantaneous stoving of thick liquid, and the solid matter in the roaster is carried to first reactor in through the conveyer, the CaSO in the solid matter₃In the first reactor with H₃PO₄Reaction is carried out to lead CaSO in the solid matter₃Complete decomposition to produce SO₂SO in the first reactor₂The gas is completely conveyed to a gas-liquid separator, which removes moisture entrained in the gas and conveys the gas to a second reactor, SO₂With excess H in the second reactor₂O₂Reacting, after the reaction is completed, back titrating SO by using NaOH₂And H₂O₂Product of the reaction H₂SO₄Wait for NaOH and H₂SO₄When the reaction is just completed, the dropping of NaOH is stopped, and CaSO in the slurry is calculated by calculating the consumption of NaOH₃The content of (a). This calcium sulfite on-line monitoring system compares with traditional iodometry, directly draws quantitative thick liquid through the sampling pump to carry it to the roaster, accomplish the stoving of thick liquid, need not measurement personnel and sample, sample on the spot, simultaneously, the sampling pump all takes a sample from a position at every turn, can realize CaSO in to the thick liquid₃The content was continuously monitored. The sample is dried and then directly conveyed to a first reactorReactor, directly completing CaSO in the first reactor₃And SO and₂is completely gasified, and the gaseous SO is separated by a gas-liquid separator₂Transfer to containing excess H₂O₂In the second reactor, SO₂And H₂O₂And (3) reaction, namely after the reaction is completed, NaOH is directly used for back titration, manual participation in a titration process is not needed, automatic control is completely adopted, operation steps are greatly simplified, operators can know the content of calcium sulfite in the slurry of the absorption tower in time, the whole system can continuously operate, and CaSO in the slurry is monitored in real time₃The content of (b) provides a basis for operators to adjust the working conditions.

Further, still include the heating part, the heating part sets up inside the first reactor.

A heating part is arranged in the first reactor for treating SO₂With excess H₂O₂After the reaction is completed, the heating component is started to ensure the SO generated by the reaction₂All become gaseous state, thereby ensuring CaSO in solid matter₃SO produced by decomposition₂Is completely transferred to a second reactor to ensure that CaSO is measured₃The accuracy of the content.

Further, the reactor also comprises a pH meter which is detachably arranged on the second reactor.

The second reactor is detachably provided with a pH meter, the pH meter can display the pH value of the reaction system in real time, and when the pH meter displays 7, the pH value represents NaOH and H₂SO₄When the reaction is just complete, the dropping of NaOH is stopped, and CaSO in the slurry can be calculated by calculating the consumption of NaOH₃The content of (a). In addition, the pH meter can monitor the pH value of the second reactor in real time, so as to monitor the reaction degree and ensure the accuracy of the detection result.

Further, a first feeding device is arranged on the first reactor.

In the first reactor, CaSO is mainly in the solid matter₃With excess H₃PO₄The slurry is dried by a roaster and then is conveyed to the first reactor by a conveyor, at the moment,the first reactor may be charged with excess H via a first charge vessel₃PO₄To make CaSO in the solid matter₃Complete decomposition and generation of SO₂A gas.

Further, a second feeding device is arranged on the second reactor.

The second reactor is mainly subjected to two-step reaction, the first step is SO₂With excess H in the second reactor₂O₂In the second step, back titration of SO with NaOH₂And H₂O₂Reaction product H of (2)₂SO₄In order to ensure the convenience of titration reaction operation, NaOH is dropwise added into the second reactor through the second batch feeder, so that the titration speed can be controlled, and the volume of the dropwise added NaOH can be read in real time.

The application also provides an online calcium sulfite monitoring method, which comprises the following steps: the sampling pump takes out the slurry from the absorption tower and sends the slurry into the roaster, the conveyor conveys the solid matters dried by the roaster to the first reactor, the product in the first reactor is conveyed to the second reactor through the gas-liquid separator, and the online monitoring of the calcium sulfite is realized by measuring the consumption of the materials in the second reactor.

The sampling pump absorbs a certain amount of slurry from the absorption tower and conveys the slurry to the roaster, the roaster instantaneously dries the slurry to obtain solid substances, and then the solid substances are conveyed to the first reactor through the conveyor, and CaSO in the solid substances₃In the first reactor with H₃PO₄Reaction is carried out to lead CaSO in the solid matter₃Complete decomposition to produce SO₂SO in the first reactor₂The gas is conveyed to a second reactor through a gas-liquid separator, SO₂With excess H in the second reactor₂O₂Reacting, after the reaction is completed, back titrating SO by using NaOH₂And H₂O₂Product of the reaction H₂SO₄Wait for NaOH and H₂SO₄When the reaction is just complete, CaSO in the slurry is calculated by calculating the consumption of NaOH₃The content of (a). Compared with the traditional iodometry, the calcium sulfite on-line monitoring method is greatly improvedThe operation steps are simplified, the detection time is shortened, and operators can know the content of calcium sulfite in the slurry of the absorption tower in time, so that a basis is provided for adjusting the working condition.

Further, the method specifically comprises the following steps:

s1, taking out the slurry from the absorption tower by a sampling pump, conveying the slurry to a roaster, and heating at the temperature of 450-650 ℃ until drying to obtain a solid substance;

s2, conveying the solid matter to the first reactor by a conveyor, and adding excessive H₃PO₄After the reaction is completed, the heating component is started to obtain SO₂A gas;

s3, adding SO₂The gas is conveyed to the gas-liquid separator to contain excessive H₂O₂In the second reactor of (a);

s4, after the reaction in the step S3 is completed, dropwise adding a NaOH solution into the second reactor until the pH value is 7, and stopping dropwise adding;

and S5, calculating the content of the calcium sulfite by measuring the consumption of NaOH.

The temperature of the roaster is set to 450-650 ℃ in S1, which can ensure that the slurry can be dried instantly and the stability of the solid matter can be ensured to prevent the solid matter from being decomposed by heat.

The chemical reaction taking place in S2 is mainly: CaSO₃+H₃PO₄＝SO₂+CaHPO₄+H₂O in addition, the heating component arranged in the first reactor can ensure SO generated by the reaction₂All become gaseous state, thereby ensuring CaSO in solid matter₃SO produced by decomposition₂Can be completely transferred to a second reactor to ensure that the CaSO is measured₃The accuracy of the content.

CaSO in solid matter in S3₃And H₃PO₄The reaction will generate SO₂And H₂O, therefore, SO in the first reactor₂Before the gas is completely transferred to the second reactor, SO needs to be separated by using a gas-liquid separator₂H carried in gas₂O is completely removed to ensure the completeness and sufficiency of the reaction, whichThe chemical reaction in the steps mainly comprises: SO (SO)₂+H₂O₂＝H₂SO₄。

The chemical reaction in S4 is mainly: h₂SO₄+2NaOH＝Na₂SO₄+2H₂O。

Further, in step S2, the H₃PO₄The concentration of (B) is 0.5-2 mol/L.

Research shows that when the concentration of reactants is increased, the number of activated molecules is increased, the frequency of effective collision is increased, the reaction rate is increased, but the reaction rate is not increased because the larger the concentration of the reactants is, the better the concentration of the reactants is, the too large the concentration of the reactants causes the reaction to be difficult to reach an equilibrium state, and the sufficiency of the reaction is influenced, so that H is calculated by an equilibrium constant relational expression₃PO₄The optimum feeding concentration is 0.5-2mol/L, at the moment, the calculated calcium sulfite content value in the slurry of the absorption tower is the most accurate, and the accuracy of the detection result is the root of ensuring the accuracy of the adjustment working condition of operators.

Further, in step S2, the heating means is turned on to maintain the temperature in the first reactor at 30-40 ℃.

To ensure the SO generated₂Completely in a gas state, the temperature in the first reactor is maintained at 30-40 ℃, the temperature is too low to achieve the required effect, and when the temperature is too high, the pressure of the first reactor is too high, so that a safety hazard exists, and meanwhile, the CaHPO can be caused by the too high temperature₄Therefore, the scheme of maintaining the temperature in the first reactor at 30-40 ℃ is optimal.

Further, in step S4, the concentration of NaOH is 0.5-2 mol/L.

In order to ensure the sufficiency and completeness of the reaction, the optimum feeding concentration of NaOH is calculated to be 0.5-2mol/L according to the equilibrium constant relational expression, and at the moment, the calculated calcium sulfite content value in the slurry of the absorption tower is the most accurate.

Compared with the prior art, the invention has the beneficial effects that:

the calcium sulfite online monitoring system is completely automatically controlled, so that the operation steps are greatly simplified, the labor intensity of laboratory staff is reduced, the accuracy of a detection result is effectively guaranteed, the operator can timely know the content of calcium sulfite in the slurry of the absorption tower, a basis is provided for the operator to adjust the working condition, the output of the oxidation fan is timely adjusted according to the content of the calcium sulfite in the slurry of the absorption tower, and the purposes of saving energy and reducing consumption can be achieved.

Drawings

FIG. 1 is a schematic diagram of an online monitoring system for calcium sulfite according to the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the device comprises an absorption tower, 2, a sampling pump, 3, a roaster, 4, a conveyor, 5, a first reactor, 6, a gas-liquid separator, 7, a second reactor, 8, a heating part, 9, a first feeding part, 10, a second feeding part, 11 and a pH meter.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise, and further, it is understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and/or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

In a specific embodiment of the on-line calcium sulfite monitoring system of the present application, an inlet of the sampling pump 2 is communicated with the absorption tower 1, an outlet of the sampling pump 2 is communicated with an inlet of the roaster 3, an outlet of the roaster 3 is communicated with an inlet of the conveyor 4, an outlet of the conveyor 4 is communicated with an inlet of the first reactor 5, an outlet of the first reactor 5 is communicated with an inlet of the gas-liquid separator 6, and an outlet of the gas-liquid separator 6 is communicated with an inlet of the second reactor 7.

In addition to the above, a heating unit 8 is further disposed inside the first reactor 5. By heating the component 8, the SO formed by the reaction can be ensured₂All become gaseous state, improve the accuracy of follow-up testing result.

In the above-described preferred embodiment, a more preferred embodiment is that the first reactor 5 is provided with a first feeder 9, the second reactor 7 is provided with a second feeder 10, and the first feeder 9 and the second feeder 10 are arranged so that H is fed to the reactor₃PO₄And the addition of NaOH is more convenient to control.

In order to more intuitively control the back titration degree, the pH meter 11 is arranged on the second reactor 7, and the pH meter 11 can monitor the pH value of the second reactor 7 in real time, so that the reaction degree is monitored, and the accuracy of a detection result is ensured.

The small test is carried out by taking the slurry of the absorption tower of a certain power plant as a treatment object as follows:

example 1

The calcium sulfite on-line monitoring system is used for on-line monitoring CaSO in the slurry of the absorption tower 1₃The content of (a). The sampling pump 2 takes 5mL of slurry and conveys the slurry to the roaster 3, the slurry is roasted at 450 ℃ for 1min to obtain solid matter, the conveyor 4 conveys the solid matter to the first reactor 5, and 20mL of H with the concentration of 0.5mol/L is added into the first reactor 5 through the first feeding device 9₃PO₄When the reaction is completed without bubbles, the heating unit 8 is turned on to maintain the temperature of the first reactor 5 at 30 ℃ for 10min, and then SO is added₂The gas passes through a gas-liquid separator 6 and is conveyed to a gas-liquid separator containing 5L H₂O₂After the reaction is completed, NaOH with a concentration of 0.5mol/L is added dropwise into the second reactor 7 through a second batch feeder 10, and when the pH meter 11 shows 7, the addition is stopped. CaSO in the slurry is calculated by calculating the consumption of NaOH₃The content of (B) is 5%.

Example 2

The sampling pump 2 takes 5mL of slurry and conveys the slurry to the roaster 3, the slurry is roasted at 650 ℃ for 1min to obtain solid matter, the conveyor 4 conveys the solid matter to the first reactor 5, and 5mL of H with the concentration of 2mol/L is added into the first reactor 5 through the first feeding device 9₃PO₄When the reaction is completed without bubbles, the heating unit 8 is turned on to maintain the temperature of the first reactor 5 at 40 deg.C for 5min, and then SO is added₂The gas passes through a gas-liquid separator 6 and is conveyed to a gas-liquid separator containing 5L H₂O₂After the reaction was completed, NaOH having a concentration of 2mol/L was added dropwise to the second reactor 7 through the second batch feeder 10, and the addition was stopped when the pH meter 11 indicated 7. CaSO in the slurry is calculated by calculating the consumption of NaOH₃The content of (B) is 7%.

Example 3

The sampling pump 2 takes 5mL of slurry and conveys the slurry to the roaster 3, the slurry is roasted at 550 ℃ for 1min to obtain solid matter, the conveyor 4 conveys the solid matter to the first reactor 5, and 10mL of H with the concentration of 1mol/L is added into the first reactor 5 through the first feeding device 9₃PO₄When the reaction is completed without bubbles, the heating unit 8 is turned on to maintain the temperature of the first reactor 5 at 35 ℃ for 5min, and then SO is added₂The gas passes through a gas-liquid separator 6 and is conveyed to a gas-liquid separator containing 5L H₂O₂After the reaction was completed, NaOH having a concentration of 1mol/L was added dropwise to the second reactor 7 through the second batch feeder 10, and the addition was stopped when the pH meter 11 indicated 7. CaSO in the slurry is calculated by calculating the consumption of NaOH₃The content of (B) is 10%.

The output of the oxidation fan is adjusted by operators according to the content of calcium sulfite in the absorption tower, and according to statistics, the output of the oxidation fan is adjusted by a 2 x 300MW unit according to the test result of the calcium sulfite every year, so that the auxiliary power can be saved by about 100 ten thousand degrees.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.