CN201098603Y - A test device for the reactivity of limestone for wet flue gas desulfurization - Google Patents

Abstract

The utility model discloses a limestone reaction activity test device for wet flue gas desulfurization, which comprises an acid reagent bottle, a reaction vessel, a constant temperature magnetic stirrer, an automatic titrator, and the acid reagent bottle and the liquid absorbing device of the automatic titrator Tube connection, the drip tube of the automatic titrator is connected to the reaction vessel, and the titration sensor of the automatic titrator and the thermometer of the constant temperature magnetic stirrer are also connected in the reaction vessel, and the rotor of the constant temperature magnetic stirrer is placed at the bottom of the reaction vessel , the acid reagent bottle is sealed and connected with the pipette of the automatic titrator. Compared with the prior art, the utility model has the characteristics of simple operation and high testing accuracy.

Description

A test device for the reactivity of limestone for wet flue gas desulfurization

technical field

The utility model relates to a test device for testing the reactivity of limestone used in wet flue gas desulfurization, which belongs to the technical field of wet flue gas desulfurization.

Background technique

China's annual SO ₂ emission reaches about 20 million tons, and it is the country with the largest SO ₂ emission in the world. Among them, coal-fired thermal power generation enterprises emit more than 8 million tons of SO ₂ every year, and they are major SO ₂ emitters. my country's air pollution is a typical soot-type pollution, and dust and acid rain are the most harmful. According to statistics, the area of my country's acid rain has reached 30% of the total land area. The key to solving the acid rain problem is to control SO ₂ pollution. Power plant flue gas desulfurization is an effective way to alleviate SO ₂ pollution. Limestone/gypsum wet flue gas desulfurization (WFGD) is currently the most widely used SO ₂ removal technology. The selection of limestone for wet flue gas desulfurization is one of the key issues in the design of WFGD system, and the main basis for the selection of limestone for wet flue gas desulfurization is its reactivity. At present, there are mainly three methods for testing the reactivity of limestone:

(1) Prepare limestone slurry, drop a certain amount of strong acid (such as HCl, _{H2SO4 ,} etc.) under certain conditions to make it react, observe the change curve of the pH value of the slurry, and judge the reactivity of limestone qualitatively.

(2) National Electric Power Industry Standard (DL/T943-2005), this method utilizes strong acid (HCl) to titrate limestone slurry under 50 ℃, PH=5.5 conditions, and the reaction time required when measuring limestone transformation rate reaches 80%, And use it as a quantitative index to judge the reactivity of limestone.

(3) A limestone activity test method and its analysis system proposed by Chongqing University (patent application number 200610054309.4), this method needs to establish a set of large-scale experimental equipment, including limestone slurry pool, slurry pump, absorption tower, gas cylinder, gas Flow controller, limestone slurry recovery tank, slurry flow controller, _SO2 concentration analysis system, PH value adjustment system, etc. This method analyzes the absorption percentage of SO ₂ in the gas by limestone slurry under certain conditions, and uses it as a quantitative index for judging the reactivity of limestone.

The advantages of the above methods (1) and (2) are that the experimental equipment used is simple, easy to control and operate. Method (1) does not define the quantitative judgment index of limestone activity size, can only rely on observation to qualitatively compare the activity of limestone; The quantitative index of reactivity has certain engineering application value, but it is difficult to directly apply this index to the optimal design model of wet flue gas desulfurization. In addition, both of the above two methods use strong acid to titrate limestone slurry, the reaction mechanism of which is quite different from that of actual wet flue gas desulfurization, and it is difficult to truly reflect the reactivity of limestone under desulfurization state. In wet flue gas desulfurization, the chemical equation of the reaction between limestone and SO ₂ can generally be expressed as (represented by CaCO ₃ and also applicable to the reaction of components such as MgCO ₃ ):

CaCO ₃ →Ca ²⁺ +CO ₃ ^2-

SO ₂ +H ₂ O→H ₂ SO ₃

H ₂ SO ₃ →H ⁺ +HSO ₃ ^-

HSO ₃ ^- →H ⁺ +SO ₃ ^2-

CO ₃ ^2- +H ⁺ →HCO ₃ ^-

HCO ₃ ^- +H ⁺ →H ₂ O+CO ₂ (aq)

CO ₂ (aq)→CO ₂ (g)

It can be seen from the above chemical equation that after SO ₂ is dissolved in water and converted into H ₂ SO ₃ , H ⁺ is ionized step by step, and after strong acid is dissolved in water, H ⁺ is ionized in one step, so the limestone in both cases The reaction rate is different; in addition, the CaSO ₃ generated by the reaction of H ₂ SO ₃ and CaCO ₃ is an insoluble substance, and when hydrochloric acid is used as the acidic reagent in method (2), the CaCl ₂ produced is an easily soluble product, and the insoluble substance It can be attached to the particle surface to affect the reaction rate, but the easily soluble product will not have such an effect. Therefore, the activity index obtained by method (2) is larger than that of the actual desulfurization. Therefore, when testing the reactivity of limestone for wet flue gas desulfurization, using strong acid as an acidic reagent has certain defects in the reaction mechanism.

If method (2) directly injects SO ₂ gas (or simulated flue gas containing SO ₂ ) into limestone slurry to measure the reactivity of limestone, there are the following problems: (a) gas flow is difficult to control and measure; (b) SO _2. The solubility in water is small (under normal temperature and pressure, 1L of water can only dissolve about 40L of SO ₂ gas), and the SO ₂ gas injected into the limestone slurry is difficult to dissolve and react quickly, and the overflow gas is difficult to collect and accurately measure. This is the main reason why the method (2) does not directly use SO ₂ gas (or simulated flue gas containing SO ₂ ) to measure the reactivity of limestone.

In order to solve the above problems, the _SO2 absorption tower was designed in the method (3), and the simulated flue gas was prepared. By measuring the _SO2 concentration in the flue gas before and after the absorption tower, the _SO2 absorption percentage was calculated and used as a criterion for judging the reactivity of limestone. quantitative indicators. However, the experimental system of this method is very large, the construction and operation costs are high, the experimental period is long, and the operation is complicated. During the experimental process, the flow field in the pipeline fluctuates greatly, and there are great difficulties in accurately measuring the SO ₂ concentration.

Due to the above reasons, the limestone activity data obtained by the above method are rarely used in the actual engineering design and desulfurization optimization model, so that the selection of relevant parameters in the wet flue gas desulfurization process mainly depends on experience. In order to ensure the desulfurization efficiency, the insurance factor is often A large amount has been obtained, which has greatly increased the investment and operating costs of the desulfurization system. Therefore, it is urgent to establish a test device for limestone reactivity with simple system, convenient operation, rapid and accurate detection, so as to improve the design level of wet flue gas desulfurization engineering and reduce the investment and operation cost of desulfurization system.

Contents of the invention

The technical problem to be solved by the utility model is to provide a testing device for testing the reactivity of limestone with simple operation and high accuracy in view of the above-mentioned deficiencies in the prior art.

In order to solve the above-mentioned technical problems, the utility model method adopts the following technical scheme: comprising an acidic reagent bottle, a reaction vessel, a constant temperature magnetic stirrer, and an automatic titrator, the acidic reagent bottle is connected with the suction pipe of the automatic titrator, and the automatic titration The drip tube of the instrument is connected with the reaction vessel, and in the reaction vessel, the titration sensor of the automatic titrator and the thermometer of the constant temperature magnetic stirrer are also connected, and the rotor of the constant temperature magnetic stirrer is placed at the bottom of the reaction vessel, and the acidic acid The reagent bottle is tightly connected with the suction tube of the automatic titrator.

It also includes a data processing device, which is connected with the automatic titrator and processes the titration information and titration time information collected by the automatic titrator.

The mouth of the acid reagent bottle is sealed with a piston, and a pipette hole and a liquid injection pipe hole are arranged on the piston, and the pipette of the automatic titrator is inserted into the pipette hole to be sealed and connected with the acid reagent bottle.

The upper end of the piston is provided with a handle.

Compared with the prior art, the acid reagent bottle of the utility model is sealed and connected with the suction pipe of the automatic titrator, which effectively prevents the volatilization of the volatile solution in the acid reagent bottle, making the measured data more accurate, and the sealing adopts a piston, which can balance the reagent The inside and outside pressure of the bottle is processed on the piston to process the injection tube hole and the suction tube hole, which can conveniently add acid reagents to the acid reagent bottle; a handle is provided on the upper end of the piston. There will be a pressure difference inside and outside the reagent bottle, so that the acid reagent can be added automatically.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the testing device of the present invention.

Fig. 2 is a schematic diagram of the piston structure of the testing device of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in detail. The test device of the utility model test method as shown in Figure 1, comprises data processing device computer 1, automatic titrator 2, reaction vessel beaker 4, constant temperature magnetic force stirrer 3, beaker 4 is placed on the constant temperature magnetic force stirrer 3, in beaker 4 contains limestone slurry, and the thermometer 5 of the constant temperature magnetic stirrer 3 is inserted into the limestone slurry in the beaker 4, and the titration sensor 7 and the drip tube 6 of the automatic titrator 2 are also inserted in the limestone slurry, and the suction of the automatic titrator 2 The liquid pipe is connected with the acidic reagent bottle 8 that is added with SO _ethanol solution. The sealing adopts a piston 9. The piston 9 is provided with a liquid injection pipe hole 91 and a liquid suction pipe hole 92. The upper end of the piston 9 is also provided with a handle 93. See attached picture 2. The ethanol solution is dripped into the limestone slurry from the dropper 6, and the automatic titrator 2 is connected with the computer 1.

Claims (4)

1. A test device for limestone reactivity for wet flue gas desulfurization, comprising acid reagent bottle (8), reaction vessel (4), constant temperature magnetic stirrer (3), automatic titrator (2), described acid The reagent bottle (8) is connected with the pipette of the automatic titrator (2), and the drip pipe (6) of the automatic titrator (2) is connected with the reaction vessel (4). In the reaction vessel (4), it is also connected with The titration sensor (7) of the automatic titrator (2) and the thermometer (5) of the constant temperature magnetic stirrer (3), the rotor of the described constant temperature magnetic stirrer (3) is placed at the bottom of the reaction vessel (4), and the acidic The reagent bottle (8) is airtightly connected with the suction pipe of the automatic titrator (2). 2. The test device according to claim 1, characterized in that it also includes a data processing device (1), the data processing device (1) is connected with the automatic titrator (2), and the titration collected by the automatic titrator Quantity information and titration time information are processed. 3. The test device according to claim 1, characterized in that the mouth of the acid reagent bottle (8) is sealed with a piston (9), and a pipette hole (92) and a liquid injection pipe hole are arranged on the piston (91), the pipette of automatic titrator (2) is inserted into pipette hole (92) and is sealed and connected with acid reagent bottle (8). 4. The testing device according to claim 3, characterized in that a handle (93) is provided at the upper end of the piston (9).

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