Installation of a wet-type flue gas desulfurization and the usage of solid substances obeserver

 

(57) Abstract:

Usage: the invention relates to a method and an apparatus for desulfurization of flue gases. The inventive exhaust gas produced from combustion equipment such as a boiler, is in contact with the absorbing liquid to absorb the sulfur oxide from the exhaust gas in the absorbing liquid; particles of limestone, which has a larger diameter, selectively left in the area where neutralized absorbing liquid that absorbs sulfur oxide in the exhaust gas and the absorbing liquid containing as the main components of the water and the gypsum formed by the sulfur oxide selectively removed from the neutralization zone again to bring it into contact with exhaust gas. At this time, the absorption liquid is brought into contact with exhaust gas contains as a major component of the water so that the quality of the product may be adversely affected due to changes in the load of the boiler, etc., For regulating the output concentration of SO2in a given range of values of concentration control more than one parameter selected from the parameters such as the flow rate of the circulating absorption liquid, under, ogliastro the introduction of a fluid-absorbing particle diameter solid obeserver substance and the moving speed of the solid obeserver substances in the zone of neutralization, thereby the output concentration of SO2installation of desulphurization for getting it in range of a preset value, by registering at least one parameter selected from the group comprising the load of the boiler, the sulfur content of fuel burned in the boiler, the flow rate of exhaust gas, the inlet concentration of SO2in the installation of desulphurization or the pH value of the absorbing liquid in the zone of neutralization or loss of pressure in the zone of neutralization, torque mixers, solids concentrations of the absorbing liquid specific gravity and viscosity of the absorbing liquid. The invention allows to increase the degree of controllability by changes in the amount of exhaust gas or the concentration of SO2. 2 C. and 7 C.p. f-crystals, 27 ill.

The invention relates to an apparatus and method of the wet-type desulfurization of flue gases, and in particular, to the installation of a wet-type desulfurization of flue gases and to a method of use of solid obeserve the boilers, with high quality desulfurization, less abrasion of the pump for circulating the absorbing fluid and a nozzle for spraying a smaller deterioration in the quality of the product because of the aluminum and fluorine components in the absorbing fluid, reduced capacity for crushing hard obestsenivaya substances such as limestone, and fine control for changes in the amount of exhaust gas or the concentration of SO2.

The sulfur oxides in flue gases produced by combustion of fossil fuels in thermal power plants and so on, especially sulfur dioxide (hereinafter referred to simply as SO2) are one of the main sources that cause global environmental problems such as air pollution, acid rain, etc., Thus, the study of methods of desulphurization of flue gases for the removal of SO2and development of plants desulfurization of flue gases, are important issues.

As such methods of desulphurization of flue gases proposed various techniques, but the main one is the handling of the wet type. Processing wet type includes sodium, calcium and magnesium ways, ispol only on the reactivity between the absorber and SO2but used sodium components are very expensive. That's why systems desulphurization of flue gases of large boilers in power plants, the most widely used calcium method that uses relatively cheap calcium components, such as calcium carbonate.

Method of desulfurization using such calcium components as the absorbing liquid, in the General case is divided into the system by spraying with a damp wall and bubbling depending on differences in the method of contacting gas and liquid. Although each system has its own outstanding features, the system will spray much more popular and more reliable, and therefore has the widest application in the world. Normal desulphurization spray once contained three towers: cooling tower for cooling the exhaust gas and the removal of dust, the desulfurization tower for spraying the absorbing liquid in the exhaust to interact with SO2and the tower of oxidation for the oxidation semitecolo calcium formed in the desulfurization tower. Recently developed dobalina system desulfurization (method of oxidation in the tank), in which the tower of obess the m as spraying systems.

Fig. 27 shows an example of a typical odnomestnoi install desulphurization spray. In General, this dobalina desulfurization system includes a housing 1 tower, intake pipe 2, an exhaust pipe 3, the spray nozzle 4, the pump 5 of the absorbing liquid, the circulation tank 6, a mixing device 7, the blower 8, the desiccant 9, a discharge tube 10 of the absorbing liquid discharge tube 11 gypsum feed tube 12 limestone, the dehydrator 13, the meter 21 pH, etc., Several spray nozzles 4 are placed in the horizontal direction, and several layers loaded in the vertical direction. Mixing device 7 and the blower 8 is connected to the circulation tank 6 located at the bottom of the desulfurization tower, where the absorbing liquid, while the desiccant 9 is installed in the highest position of the desulfurization tower or into the exhaust pipe 3.

Exhaust gas A, produced from a boiler is introduced into the housing 1 of the desulfurization tower from the inlet tube 2 and exits through the discharge tube 3. In the course of such process to the tower, desulfurization pumps 5 absorbing fluid through the discharge tube 10 of the absorbing liquid is pumped pogo absorbing fluid and exhaust gas A. When this spray SO2selectively absorbed by the absorbing liquid from the exhaust gas to A education semitecolo calcium. Absorbing liquid containing the so formed sanitarily calcium remains in the circulation tank 6, where the agitation mixing device 7 sanitarily calcium in the absorbing liquid is oxidized by air B supplied by a blower 8, prior to the formation of gypsum C. Obeserve substance, such as limestone D is added to the absorption liquid in the circulation tank 6 through the limestone feed tube 12. Part of the absorbing liquid in the circulation tank 6, where the limestone D and gypsum C, again pumped by the pump 5 of the absorbing liquid to the spray nozzle 4 through the discharge tube 10 of the absorbing liquid, while the other part is pumped to the dryer 13 through the discharge pipe 11 of gypsum to collect gypsum C after dehydration. Small droplets absorbing fluid, hogging the spray nozzle 4, are fond of exhaust gas A and going desiccant 9 located on the upper part of the desulfurization tower.

However, it is shown in Fig. 27 analog has the following disadvantages.2but a significant amount of gypsum that nothing contributes to the absorption. If the absorbing liquid increases the proportion of limestone to improve the quality of the product, the quality of gypsum reduced to an unusable level.

(2) For grinding of limestone consumed significant energy supply.

(3) When the absorbing liquid are also aluminum and fluorine components on the surfaces of the limestone particles are formed inactive mixture containing aluminum and fluorine, which degrades the quality of desulfurization.

Accordingly, the objective of the present invention is to provide installation and method of desulfurization of flue gases in order to solve the above conventional problems, and economical achievement of higher quality of desulfurization.

Another objective of the present invention is to provide installation and method of desulfurization of flue gases, can improve the quality of the product without reducing the quality of the gypsum produced in the process.

Another objective of the present invention is to provide installation and method of desulfurization of flue gases with high quality desulfurization, soubrette is to ensure the installation and method of desulfurization of flue gases with high quality desulfurization, can easily divide the limestone contained in the absorbing liquid, and formed it in plaster.

Another additional objective of the present invention is to provide installation and method of desulfurization of flue gases, able to retain a high quality product regardless of changes in load of the combustion equipment, such as boiler and so on, or in the concentration of sulfur oxides in flue gases.

Other objectives of the present invention will be described in the following examples.

The present invention provides the following method and the device are:

the method of wet-type desulfurization of flue gases using solid obeserver substances, in which the exhaust gas produced from combustion equipment such as a boiler, is in contact with the absorbing liquid, solid obeserve substance selectively left in the neutralization area to neutralize the absorbing fluid containing sulfur oxide absorbed thereby from the exhaust gas, the reaction product produced from the sulfur oxide and the absorbing liquid containing water as a main component, selectively displayed, and absorbing fluid drained so from the tives such as those for detection is selected more than one parameter from the parameters such as the load of the boiler, the sulfur content of fuel burned in the boiler, the flow rate of exhaust gas, the input/output concentration of SO2in the installation of desulphurization or pH value of the absorbing liquid in the zone of neutralization or loss of pressure in the zone of neutralization, torque mixing device, the concentration of solids in the absorbing liquid, the specific gravity of the absorbing liquid and the viscosity of the absorbing fluid to control more than one parameter selected from the parameters such as the flow rate of the absorbing liquid circulating to ensure contact with exhaust gas, the amount of solid obeserver substances, be inserted in a fluid-absorbing particle diameter solid obeserver substances and the rate of mixing of solid obeserver substances in the zone of neutralization, thereby the output concentration of SO2installation of desulphurization for getting it in range of a predetermined value; and

installation of a wet-type desulfurization of flue gases using solid obeserve substance, stereoshared with the absorbing liquid, then solid obeserve substance selectively left in the neutralization area to neutralize the absorbing fluid containing sulfur oxide absorbed thereby from the exhaust gas, and the reaction product is produced from sulphur oxides, and absorbing liquid containing water as a main component, selectively displayed, and the circulation channel of the absorbing liquid for further contact of the absorbing liquid drained from the neutralization zone, with waste gas, which device comprises detecting means for detecting more than one parameter selected from the parameters such as the load of the boiler, the sulfur content of fuel burned in the boiler, the flow rate of exhaust gas, the input/output concentration of SO2in the installation of desulphurization or pH value of the absorbing liquid in the zone of neutralization or loss of pressure in the zone of neutralization, torque mixing device, the solids concentrations of the absorbing liquid, the specific gravity of the absorbing liquid and the viscosity of the absorbing fluid regulating agent selected from the group consisting of more than one measure to regulate such parameters as flow rate posega substances, be inserted in a fluid-absorbing particle diameter solid obeserver substances and the rate of mixing of solid obeserver substances in the neutralization area according to the detected mentioned detecting means value, and control means for controlling the output concentration of SO2installation of desulfurization to get into the range of predetermined values according to the action mentioned regulating means.

Mixing device for a layer of limestone used here to adjust the speed of stirring the solid obeserver substances in the neutralization area includes the area of neutralization mixing device equipped with mixing blades or scrapers, rotation of the neutralization zone, etc.

Solid obeserve substance used in the present invention preferably has a medium-weighted particle diameter (hereinafter simply mean diameter of particles greater than 0.5 mm, a Substance with an average particle diameter of less than 0.5 mm would impede the Department obeserver substances from the reaction products of oxidation, such as gypsum, and would lead to reduction of the sizes of kastanovqe desulphurization of flue gases. More preferably, the solid obeserve substance had average particle diameter is more than 1.0 mm Solid obeserve substance with an average particle diameter of more than 10 mm would reduce reactivity to neutralize the absorbing fluid, which absorbs SO2in the exhaust, and besides, it was Easter would feed tube solid obeserver substance, which is connected with the neutralization area installation of desulphurization of flue gases. Accordingly, solid obeserve substance used in the present invention preferably has an average particle diameter of from 0.5 to 10 mm, However, the solid obeserve substance in the present invention may contain particles less than 0.5 mm, because videostenny desired average particle diameter is a standard, which is not limited strictly.

In the present invention it is desirable to apply solid obeserve substance in the area of neutralization way air transfer in suspension or in the dried state.

The volume of the solid obeserver substance subject to filing in the neutralization area, is governed by the dispenser or operation on-off crushers for hard obeseity crusher, etc.

Limestone is a typical example of solid obeserver substances used in the present invention. The so-called limestone, used here, means a sedimentary rock containing calcium carbonate as the main component, and further comprises in the present invention the rocks containing carbonate magnesium. Accordingly, the present invention also includes dolomite, which contains as the main components of CaCO3and MgCO3. Because the limestone contains impurities that affect the quality of the product, it is desirable that CaCO3having a higher reactivity, was naked on a solid surface by grinding such impurities. However, because solid obeserve substance with particles of smaller size easier is included in the solid products, such as gypsum, these smaller particles must be pre-separated and removed, even if they have higher reactivity. On the other hand, excessively large particles would spoil the feeding zone of the solid obeserver substances, therefore, it is desirable that the feed area was equipped with a filter or a cyclone for separating solid obeserver prophetic is reportedly absorbing liquid (the main component is water) to form in her H2SO3and the absorbing liquid that has absorbed SO2that is oxidized by air to H2SO4(diluted sulphuric acid). H2SO4neutralized solid obesityvisit substance (in this case, limestone, presents CaCO3i.e. the main component in the formula of the reaction) to the solid product (in this case, gypsum CaSO42H2About). The most characteristic feature of the present invention is used as obeservation substances limestone, and the limestone has a particle diameter greater than that of the gypsum formed by neutralizing containing H2SO4fluids with a high pH value.

Below are the main reactions occurring in the installation of desulphurization of flue gases according to the present invention. The following formulas (1) to (3) reactions are presented as a typical reaction for a better understanding of the present invention, and it is believed that all reactions in the installation of desulphurization of flue gases do not always correspond to formulas (1) to(3).

(Reaction absorption) H2O+SO2= H2SO3; (1)

(Oxidation reaction) H2SO3+1/2O2= HCO2(3)

In the installation method according to the invention the absorbing liquid containing H2SO4(diluted sulphuric acid), flows, carrying in itself the limestone, through a zone in which the absorbing liquid is neutralized with limestone to produce the above neutralization reaction so that the pH value of the absorbing liquid will increase. Limestone again served in the above-mentioned neutralization area in this volume, which is required for the reaction. However, if the pH value for a regulation subject to the filing of the amount of limestone is determined after neutralization, as the measurement of its volume in the zone of neutralization unenforceable, the supported amount of limestone increases too for absorbing liquid flowed freely when changing the diameter of the particles of limestone, which is the difficulty in regulating the amount of limestone to be serving.

On the other hand, can accurately measure the volume of limestone by measuring not only the pH value of the absorbing liquid, and the pressure loss in the layer of limestone, the moment of mixing device, the solids concentration in the absorbing liquid, specific gravity of the absorbing liquid, the viscosity of Pogos and is also determined by specific gravity of the absorbing liquid, even if the amount of limestone is not changed. In addition, there is a relationship between the specific gravity of the absorbing liquid and the viscosity of the absorbing fluid or the concentration of solids (essentially of particles of gypsum). In General, the loss of pressure (P) of the current layer is expressed by the following formula:

P = (specific gravity of limestone - specific gravity of the absorbing liquid) (the height of the layer of limestone) (1 - porosity coefficient)

The porosity coefficient in this formula is the value in a state of fluidity, but the work (the height of the layer of limestone) (1 - porosity coefficient) is the same under conditions of stationarity and fluidity, so that the height of the layer of limestone in the state of stationarity can be defined by the same formula. In other words, since the proportion of limestone known (about 2.7) and its coefficient of porosity in the condition of stationarity is about 0.4, while depends on the particle shape, the height of the layer of limestone is obtained from the definition of loss of pressure P and specific gravity of the absorbing liquid. Further, since the specific gravity of the absorbing liquid is associated with the concentration of particles (in this case essentially by the concentration of particles of gypsum) or the viscosity of the absorbing liquid, such concentration is the height of the layer of limestone and pressure loss, which are proportional to each other when the concentration of solids in the absorbing liquid is constant. Thus, when changing the concentration of solids (specific gravity) of the absorbing liquid, the height of the layer of limestone can be assessed by pre-determining the relationship between the height of the limestone and the pressure loss that was easy to control the concentration of SO2corresponding to the volume of exhaust gas, or by changing the concentration of SO2in the exhaust by adjusting the supplied amount and/or size of particles of limestone.

Fig. 1 is a conditional form odnomestnoi installation of a wet-type flue gas desulfurization according to the first example of the present invention.

Fig. 2 is an enlarged view of the zone of neutralization in Fig.1.

Fig. 3 is a cross-section area of neutralization along the line a-a in Fig. 2.

Fig. 4 is a section of a modified example of the neutralization zone along the line a-a in Fig. 2.

Fig. 5 is a graph showing the relation between the height of the layer of limestone and the pressure loss according to the present invention.

Fig. 6 is a flowchart of the control algorithm setup Alenia according to the first example.

Fig. 8 is a graph showing the relation between the state of the input gas and a preset value of the height H of the layer of limestone obtained from the ratio of desulfurization.

Fig. 9 is a graph showing the change with time of the ratio of desulfurization in the first example (solid line (a)), in the second example (the dotted line (b)) and in comparative example 1 (dash-dotted line (C)).

Fig. 10 is a conditional form odnomestnoi installation of a wet-type desulfurization of flue gases according to the second example of the present invention.

Fig. 11 an enlarged view of the neutralization device of Fig. 10.

Fig. 12 is a flowchart of the control algorithm odnomestnoi installation of a wet-type desulfurization of flue gases according to the second example shown in Fig. 10.

Fig. 13 is a flowchart of the control algorithm odnomestnoi installation of a wet-type desulfurization of fuel gases used in comparative example 1.

Fig. 14 is a flowchart of the control algorithm odnomestnoi installation of a wet-type desulfurization of fuel gases used in the third example of the present invention.

Fig. 16 is a graph showing the relation between the input concentration of SO2and the ratio of liquid-gas (L/G) in the cases of the third example (solid line) and comparative example 3 (the dotted line (b)).

Fig. 17 is a graph showing the relation between (W/G) and the coefficient of desulfurization in the cases of the third example (solid line) and comparative example 3 (the dotted line (b)).

Fig. 18 is a graph showing the relation between G/G and the input concentration of SO2to obtain the ratio of desulfurization 90% in the cases of the fourth example (solid line) and comparative example 4 (the dashed line (b).

Fig. 19 is a conditional form odnomestnoi installation of a wet-type flue gas desulfurization according to the fifth example of the present invention.

Fig. 20 is a conditional form of neutralization device according to the sixth and seventh examples of the present invention.

Fig. 21 is a graph showing the result of the input concentration of SO2by changing the W/G in case of the sixth example (solid line (a)) and the fifth example (UB> according to the seventh example of the present invention.

Fig. 23 is a conditional form of drying kiln wet process is used as a neutralization device according to the eighth example of the present invention.

Fig. 24 is a conditional form prescribed under the circulation tank scraper used as a neutralization device according to the ninth example of the present invention.

Fig. 25 is a conditional form of horizontal (or transverse) odnomestnoi installation of a wet-type flue gas desulfurization according to the tenth example of the present invention.

Fig. 26 is a conditional form odnomestnoi installation of a wet-type flue gas desulfurization, provided with outer tower oxidation, according to the eleventh example of the present invention.

Fig. 27 is a conditional form of traditional odnomestnoi installation of a wet-type flue gas desulfurization.

The present invention will be described in detail below by way of examples, but it is not intended to limit to these examples.

The first example

Dobalina installation of a wet-type desulfurization Drogo type for desulfurization of flue gases includes a housing 1 tower desulfurization, the intake pipe 2, an exhaust pipe 3, the spray nozzle 4, the pump 5 of the absorbing liquid, the circulation tank 6, a mixing device 7, the blower 8, 9 desiccant, limestone feed tube 12, the opening-closing valve 31 to the feed tube 12, etc., and further comprises measuring 21 pH for pH measurements of circulating absorbing fluid, the pressure gauge 22 for measuring the pressure loss in the current limestone layer 19, the hydrometer 23 for measuring the specific gravity of the absorbing liquid, the opening-closing valves 24, installed in the joints between the pipe 16 and the distributing tubes 17 in order to give the absorbing liquid is able to flow to a specific distribution tubes 17, and the partition 25 for separation of limestone in the area of neutralization by numerous departments. In addition, in the intake pipe 2 of the desulfurization tower mounted gas flow meter 27 and the intake pipe 2 and the exhaust pipe 3 is installed gauges 28 concentration of SO2as described above, the pressure gauge 22 and hydrometer 23 serves signals to the control unit 30, which generates a signal to the opening-closing valve 31 limestone feed tube 12, the pumps 5 absorbing fluid, od A, coming from a boiler is introduced into the housing 1 of the desulfurization tower from the inlet pipe 2 and is removed from the exhaust pipe 3. During this process, the absorbing liquid is pumped by pump 5 of the absorbing liquid sprayed into the tower desulfurization through many nozzles 4 to ensure contact of the gas-liquid between the absorbing liquid and the exhaust gas A. At this time, droplets absorbing fluid selectively absorb SO2from the exhaust gas A before the formation of sulphurous acid. Thus formed droplets absorbing fluid containing sulfurous acid, fall on the collecting liquid plate 14 installed on the circulation tank 6. Falling on collecting liquid plate 14 absorbs the liquid is collected and passed to the bottom of the circulation tank 6 through the introduction pipe 15. On the way sulfurous acid in the absorbing liquid is oxidized to sulfuric acid oxidizing air B, which is blown from the blower 8. Many distribution tubes 17 are connected by a pipe 16 with the bottom part of the introduction pipe 15 in order to give the absorbing liquid can move up uniformly. Each distributing tube 17 has a multitude of distributing holes ih upstream. Sulfuric acid and limestone react in the current layer of limestone to form gypsum, but the particles of gypsum and water are produced from the circulation tank 6 through the outlet 20 of the absorbing liquid in the upper part of the tank rising flow of the absorbing liquid, and limestone selectively left in the circulation tank 6, because the particles of gypsum smaller particles of limestone.

Fig. 2 and 3 show the detailed construction of the parts of the circulation tank 6, where the limestone layer 19, and Fig. 2 is a side view, and Fig. 3 is a section along line a-a in Fig. 2. According to this example, the pipe 16 is connected with the side surfaces of the bottom part of the introduction pipe 15, and the set of distribution tubes 17 are evenly distributed from the nozzle 16 on the entire surface of the bottom of the circulation tank 6. The partition 25 is separated distributing tube 1 from one another and particles of limestone in the area of neutralization of the absorbing fluid in many departments. In addition, the absorbing liquid is supplied independently to each Department by the opening-closing valves 24, each of which is mounted at the junction between each distribution tube 17 in each Department Esti 18 can be maintained above a specified level, even if the circulating volume of the absorbing liquid is reduced. Additionally measured pressure loss in the current limestone layer 19 in each Department and specific gravity of the absorbing liquid, respectively, a pressure gauge 22 and a hydrometer 23. Although shown only one pressure gauge 22, it is provided in each Department.

As described above, the absorbing liquid, neutralized thus, in the neutralization area to restore the pH is returned to the nozzles 4 from the exhaust hole 20 located on the upper part of the circulation tank 6, through the discharge tube 10 of the absorbing liquid to absorb SO2from the exhaust gas A, as shown in Fig. 1. Part of the absorbing liquid is supplied to the meter 21 pH to measure the pH value of the absorbing liquid after neutralization. Further, part of the absorbing liquid is supplied to the dryer 13 to collect C. gypsum Limestone D, comminuted not shown crusher of particles, each of which has a specified diameter, served in the circulation tank 6 through the limestone feed tube 12.

When the circulation tank 6 has a cylindrical shape, an introduction pipe 15, the pipe 16, raspredelyaemy the Lena, as is shown in Fig. 4 in cross section along the line a-a in Fig. 2. In addition, the joints between the pipe 16 and the distributing tubes 17 is provided by an opening-closing valve 24, as shown in Fig. 1 and 2, although they are not shown in Fig. 4.

This example is characteristic, consisting in the fact that the formation of the upward flow of the absorbing liquid in the limestone layer 19 in the neutralization area inside the circulation tank 6 eliminates the need for such equipment as agitating device for agitating limestone and the unit for installation, as well as the need for food to bring it in motion.

Fig. 6 shows a block diagram of the control algorithm of the installation of desulfurization according to this example.

Amount of limestone (the volume obtained from gypsum) can be obtained from the velocity of the gas stream in the intake pipe 2, the concentration of SO2in the intake pipe 2 and the exhaust pipe 3 of the desulfurization tower. The actual volume of limestone supply is regulated so that the actual measured consumption of limestone can be adapted to the calculation. On the other hand, the desired ratio of liquid-gas (L/G - ratio atributa the ü offices among many separated from each other by partitions 25 departments according to the flow volume (the volume of circulation) of the absorbing liquid can be obtained from the concentration of SO2in the intake pipe 2 of the desulfurization tower, a predetermined value of the degree of desulfurization and the pH value of the absorbing liquid after neutralization, for such regulation number filing of a fluid-absorbing branches, so that the ratio W/G was equal to the computed value.

It should be noted that the number of branches, which served absorbing liquid is adjusted by opening the opening-closing valves 24 specific departments to be used among the set formed by the partitions 25 branches in the zone of neutralization, disposal absorbing fluid from the distributing holes 18 distribution tubes 17, which correspond to open the opening-closing valves 24.

Fig.7 shows an example of the relationship between the ratio W/G and an inlet concentration of SO2the more specified values of the degree of desulfurization and the concentration of SO2in the intake pipe 2 of the desulfurization tower, or the lower the pH value of the absorbing liquid after neutralization, the more it becomes necessary relationship W/, But on the ratio between the W/G and these factors influence the design of the tower desulfurization or microascales provided the tower desulfurization mainly controlled by regulating the supply pump 5 of the absorbing liquid, for example, by adjusting the number of operating pumps 5 absorbing fluid.

When the ratio W/G is changed, controlled opening-closing valve 24 to maintain the speed of ejection of the absorbing liquid from the distributing holes 18 in the specified range. When the speed of ejection of the absorbing liquid from the distributing holes 18 is too large, limestone D is derived from the neutralization together with particles of gypsum C, so that the quality of the gypsum C uhudshatsa. On the other hand, when the speed is too low, the fluidity of the limestone becomes insufficient, so that the neutralization rate (factor () method) is reduced.

As described above, even if the determined operating conditions, the factor () method sometimes is different from a predetermined value. One of the reasons is that the error (the error of the meter during measurement of the flow velocity and the concentration of SO2) in the required amount of limestone D, obtained from the gas flow velocity in the intake pipe 2 of the desulfurization tower and the concentration of SO2in its intake pipe 2 and the exhaust pipe 3, is manifested in the change of the amount of limestone in the neutral zone is C limestone D, supplied to the circulation tank 6 through the limestone feed tube 12 (change in ability by itself limestone to grinding or chopping change the ability of the crusher).

To solve this problem, according to this example, the volume flow and the diameter of the particles of limestone D are regulated on the basis of the difference between the assigned values and the measured values of the degree of desulfurization and the height H of the layer of limestone, with set values are obtained by comparing the actual measured values of the factor () method with its given value, and the height H of the limestone layer is calculated by subtracting the losses (P) pressure in this limestone layer 19, as measured by the pressure gauge 22 and a hydrometer 23, and specific gravity of the absorbing liquid in the following equation:

P = (specific gravity of limestone - specific gravity of the absorbing liquid) (the height of the layer of limestone) (1 - porosity coefficient).

The diameter of the particles of limestone D can be adjusted by means of the method known from analogues, such as the amount of limestone D is supplied to a crusher (not shown), the working conditions of the crusher, etc., the Height H of the limestone layer must be installed previously on enougha, when the state of the input gas (gas flow rate and the concentration of SO2in the intake pipe 2 and the exhaust pipe 3 of the desulfurization tower) was changed by an amount greater than the specified value, the amount of limestone supply again was regulated on the basis of the state of the input gas.

Using limestone with medium-weighted particle diameter of 2 mm (the height of the layer of limestone H = 50 cm) in the installation according to this example was tested desulfurization. However, the amount of exhaust gas was constant in the inlet hole of the desulfurization tower, a SO2in the exhaust A regulated so as to be 1000 ppm and 50 ppm respectively in the inlet and outlet pipes of the desulfurization tower. The height H of the limestone layer was maintained at a constant level 50 see the Solid line (a) in Fig. 9 represents the change in the degree of desulfurization in time. The concentration of SO2outlet tube is stable. In addition, the height H of the limestone layer was the same at the beginning of the test and after it.

The second example

Fig. 10 shows the installation of desulfurization according to this example. Check desulfurization was carried out using the same device is whodunnit holes 29 for blowing air into the limestone layer 19 in the installation, presented on Fig. 1, to facilitate additional agitation of the current between limestone. Fig. 11 is an enlarged conditional form of the neutralization zone. According to this example, the speed of stirring the limestone layer 19 with the help of air is controlled by varying the volume of air supplied to the zone of neutralization, instead of regulating the diameter of the particles of limestone D. Instead of air can be injected into the limestone layer 19 water.

The block diagram of the control algorithm used in this example shown in Fig. 12. The change with time of the percentage desulfurization shown by a dotted line (b) in Fig. 9. As in the case of the first example, received a stable characteristic of desulphurization, the height H of the limestone layer after the scan was the same as before the test.

Comparative example 1

Check desulfurization was carried out using a typical installation of desulphurization shown in Fig. 27. Because it was impossible to determine the height of the limestone in the comparative example, be the supply amount of limestone was regulated by the concentration of SO2outlet tube of the desulfurization tower. The block diagram of the control algorithm, ispolzuemogo is provided with a dash-dotted line in Fig. 9. Compared with examples 1 and 2 feature desulfurization significantly changed, and the height of the limestone layer after the test was 1.5 times higher than pre-test.

Example 3

Check desulfurization was carried out using the same setup and under the same conditions as in the first example. In this example, the amount of limestone to be serving, not regulated by the state of input gas velocity of the gas stream and the concentration of SO2in the intake pipe 2 and the exhaust pipe 3 of the desulfurization tower), but as the specified volume and the diameter of the particles of limestone was regulated on the basis of the height of the limestone layer, defined by a loss (P) pressure limestone layer and the specific gravity of the absorbing liquid. When the circulation rate of the absorbing fluid was changed due to regulation W/G, the rising speed of flow of the absorbing liquid in the supply of a fluid-absorbing offices in the neutralization area was regulated by the opening-closing valve 24 so as not to decrease below 4 cm/s Block diagram of the control algorithm used in this example shown in Fig. 14. As in the case of the first example, received a stable characteristic of obess the La is the same as before the test. The correlation between the quality of desulfurization and the ratio W/G in this example is shown as a solid line (a) in Fig. 17.

Comparative example 2

Check desulfurization was carried out using the same setup as in example 3, except that the number of feed of a fluid-absorbing branches in the zone of neutralization was not regulated. The block diagram of the control algorithm used in this comparative example shown in Fig. 15.

The ratio between the inlet concentration of SO2and the ratio W/G in the case of example 3 and comparative example 2 are shown respectively by the solid line and dashed line (b) in Fig. 16. It is obvious that in comparative example 2, which is not regulated by the number of feed absorbing fluid outlets, the value of W/G with the same inlet concentration of SO2was higher than in example 3.

Comparative example 3

Check desulfurization was carried out using the setup shown in Fig. 27, under the same conditions as in the case of example 3. The obtained result is shown by a dotted line (b) in Fig. 17. Compared with the result of example 3, shown by the solid line (a) on the same drawing, the lower protistologist, that limestone is not enough liquefy, decreases when the ratio W/G (i.e., when the volume of liquid decreases due to the fact that the volume of the gas constant).

Example 4

Check desulfurization was carried out using the same setup as in the first example, in the range of inlet concentrations of SO2varying from 200 to 2000 parts per million. The ratio between the ratio W/G and an inlet concentration of SO2to obtain 90% desulfurization shown by the solid line (a) in Fig. 18.

Comparative example 4

Check desulfurization was carried out using the setup shown in Fig. 27, under the same conditions as in the case of example 4. In comparison with example 4, the ratio W/G is not easily reduced at lower input concentrations of SO2. You can suggest that limestone is not enough liquefies when the ratio W/G is reduced (i.e. when the volume of liquid decreases due to the fact that the volume of the gas constant).

Example 5

Used in examples 1-4 installation of desulphurization have a construction in which the limestone liquefied in the circulation tank 6, and the outside of the tank is separated. On the other hand, as shown in Fig. 19, lots neutralization unit is a rotary connecting tubes 34. Each connecting tube 34 is equipped with an opening-closing valve 24 to eject the absorbing fluid through the distributing holes distributing tubes (not shown; they are the same as those used in Fig. 2 and 3), mounted on top of the bottom part of the neutralization unit 33. Instead of, or together with throwing absorbing fluid through the distribution holes in the distributing tubes can be arranged Duval 26 air or water and air or water holes 29, as shown in Fig. 10 and 11. Neutralization block 33 mounted independently from the body 1 of the desulfurization tower, can be isolated, although it is not shown in Fig. 19, or a single neutralization unit 33 inside can be separated as in the case of the first example (see Fig. 2 and 3).

The block diagram of the control algorithm in this example is the same as in Fig. 6. In this case, the opening-closing valve 24 distributing tube 17 in Fig. 1 corresponds to the opening-closing valve 24 connecting tube 34 in Fig. 19.

In the installation method shown in Fig. 19, between the neutralizing unit 33 and the circulation pump 5 may be equipped with a separator for separating WPI is 33 shaken by the agitator 36 instead of education vent stream absorbing fluid through the distribution tubes 19 in the neutralization unit 33 or insufflation of air. The enlarged view of neutralization unit 33 shown in Fig. 20.

Limestone, medium-weighted particle diameter of 1 mm or more is loaded to the formation of a current of air bags in the neutralization unit 33. These limestone particles and gypsum particles (with an average weighted particle diameter of from 10 to 100 microns) are easily separated due to the significant difference in their diameters. Accordingly, the amount of limestone neutralization unit 33 does not depend on the quality of the gypsum, and the more limestone is loaded, the faster neutralized absorbing liquid, preferably the weight ratio of the absorbing liquid limestone is from 9:1 to 6:4.

Limestone with larger diameter particles constantly shaken in the absorbing liquid by the agitator 36. Absorption liquid is fed into the neutralization unit 33 of the circulation tank 6 (see Fig. 19), whereas limestone is loaded from limestone feed tube 12. Can be used a design in which the limestone with a smaller diameter of the particles is also served, as appropriate, of limestone feed tube 37. The block diagram of the control algorithm used in this example is the same as in Fig. 6, only the at the time of the agitator 36 and the height of the limestone layer should be determined in advance.

Check desulfurization was carried out using the above setup. The concentration of SO2in the exhaust in the intake pipe of the desulfurization tower was 1000 ppm. Limestone (with a medium-weighted particle diameter of 5 mm) pre-loaded in the neutralization unit 33 in equimolar amount in relation to the SO2in the exhaust output for two hours, and then was served on him in the amount of 0.97 molar ratio of SO2in the exhaust from the limestone feed tube 12. The volume of air before injection into the circulation tank 6, was thirty power scope in a molar ratio to the SO2in the exhaust.

Change the outlet concentration of SO2in the desulfurization tower, when you change the intake, the concentration of SO2shown as a solid line (a) in Fig. 21. In this case, the pH value of the absorbing liquid discharged from the neutralization unit 33, was determined by measuring 21 pH values (see Fig. 19) for controlling the rotational speed of the agitator 36 so as to maintain the pH value is approximately constant before and after the change in inlet concentration of SO2while the final concentration of SO2determined to change the relationship W/ the band and restores its original set value in a short time, even if you change the inlet concentration of SO2.

Comparative example 5

Repeat the procedure of example 6, but the frequency of rotation of the agitator 36 is maintained constant, when the inlet concentration of SO2tower desulfurization was changed, then the ratio W/G was changed to control the final concentration of SO2(the ratio W/G was regulated mainly by regulating the number of pumps 5 absorbing fluid, etc). Thus obtained result is shown by a dotted line (b) in Fig. 21. Compared with example 6 in this comparative example, there is a noticeable change in final concentrations of SO2and requires more time to restore the original preset value.

Example 7

Repeat the procedure of example 6, but the frequency of rotation of the agitator 36 is maintained constant, when the inlet concentration of SO2tower desulfurization was changed, while in the neutralization unit 33 of the feed tube 37 was applied limestone with medium-weighted particle diameter of 10 μm (hereinafter referred to as the smaller limestone). Such smaller limestone was added there from limestone feed tube 37 to maintain a pH of approximately Kee the O2changes in a small range and restores its original set value in a short time, even if the inlet concentration of SO2.

Example 8

Although in the examples 6 and 7 as a neutralization unit 33 uses the tank with agitator 36, shown in Fig. 20, block 33 can be used, for example, shown in Fig. 23 drying oven. In this example, it is possible to regulate the residence time of the absorbing liquid in a drying oven 38 by changing the frequency of rotation of the drying oven 38 instead of the frequency of rotation of the agitator 36, shown in Fig. 20, or by returning part of the absorbing liquid in the inlet pipe drying oven 38 through line 40 through valve 39 mounted in the exhaust pipe of the furnace, instead of the control level of the absorbing liquid level in the tank) in the neutralization unit 33 in Fig. 20.

Example 9

Although in examples 5-8 neutralization unit 33 is installed outside of the desulfurization tower, you can also, as shown in Fig. 24, positioned in the lower portion of the circulation tank 6 scraper 42, upload crushed limestone D in the circulation tank 6 for the formation of the limestone layer 19 and upravit, functioning similarly to the same parts used in example 6, are numbered with the same reference position, and further description in this example is omitted.

This example uses the separator 43. Containing gypsum C absorbing fluid released from the circulation tank 6, is pumped into the separator 43 through a pump 44 for separating gypsum C. Then, the liquid containing some limestone D, and the advantage of gypsum C, served in the dehydrator 13 for dehydration and collection of plaster C.

Although all the above examples, the limestone D is selectively left in the neutralization area through the use of benefits from different deposition rate due to the difference in diameter of the particles of limestone D and gypsum C, can be divided limestone and gypsum in other ways, such as through a net or through the use of benefits from the difference in force of inertia. Further, although all of the examples described desulfurization tower, which is designed for introducing exhaust gas from the bottom and removing it from its upper part when spraying the absorbing liquid in the exhaust through a nozzle, the present invention is effectively applicable also to those who gosausee liquid and waste gas (such as absorbing unit with wet wall system or ozonation, in which exhaust gas is introduced into the absorption liquid through immersed in her tube) or horizontal installation of a wet-type desulfurization of flue gases, in which the flow of exhaust gas is forced to go not in the vertical direction.

Example 10

This example uses the horizontal installation of a wet-type flue gas desulfurization. The present invention is effectively applicable to horizontal (inclined) the installation of a wet-type desulfurization of flue gases, in which exhaust gas is not in the vertical direction, as shown in Fig. 25. All equipment and parts, functioning similarly to the same parts used in the first example, are numbered with the same reference position, and further description in this example is omitted. Tower desulfurization of this installation includes a housing 1 of the desulfurization tower, the inlet pipe 2 and an exhaust pipe 3. The intake pipe 2 provided with a nozzle 4 for spraying the absorbing liquid into the intake pipe exhaust to absorb SO2in the liquid, which then falls into the circulation installed in the lower part of the tower desulfurization tank 6 for cepelinai moisture from the tower desulfurization out.

Coming out of the boiler exhaust gas And is introduced into the desulfurization tower 1 from the inlet pipe 2 and is removed from the exhaust pipe 3. During this process, the absorbing liquid is sprayed in the tower desulfurization through many nozzles 4 by pump 5, providing contact gas-liquid between the absorbing liquid and waste gas. Thanks SO2in the exhaust selectively absorbed in the absorbing fluid to the formation of sulphurous acid. Formed in this way, droplets containing sulfurous acid, fall on the collecting liquid plate 14 installed on the circulation tank 6. Absorption liquid is collected on the collecting of a fluid-absorbing plate 14 and introduced into the bottom portion of the circulation tank 6 through the introduction pipe 15. On the way sulfurous acid is oxidized oxidizing air B, which is blown from the blower 8, prior to the formation of sulfuric acid. In the bottom of the introduction pipe 15 through the pipe 16 arranged many distribution tubes 17 for uniform flow of the absorbing liquid up, each distributing tube 17 has a multitude of distributing holes (not shown). Through these distribution holes with the power emitted in azueta during the reaction between sulfuric acid and limestone, the ascending flow of the absorbing liquid from the circulation tank 6 through 20 for absorbing fluid, located in the upper part of the tank 6 displays only the particles of gypsum and water, and limestone selectively left in it, because the diameter of the particles of gypsum is less than the diameter of the particles of limestone. Neutralized in the limestone layer 19 absorbing liquid is passed through a discharge tube 10 of the absorbing liquid and is pumped to the nozzles 4 by means of pumps 5 absorbing fluid. Part neutralized thus absorbing fluid is pumped into the dehydrator 13 for dehydration and collection of plaster C. Instead of placing the limestone layer 19 in the absorbing fluid within the circulation tank 6, as shown in Fig. 25, neutralization unit 33 can be installed on the outside of the circulation tank 6 for placing therein crushed limestone.

The block diagram of the control algorithm used in this example is the same as shown in Fig. 6 in example 1. On the other hand, another block diagram of the control algorithm is similar to Fig. 14, when the amount subject to the filing of the limestone is not regulated by the state of the inlet gas (flow rate of gas to iroute based on the height H of the limestone layer, certain through loss (P) pressure in the limestone layer 19 and the specific gravity of the absorbing liquid.

Further, the present installation of desulphurization in this example, may be provided with an air or water injector 26 and the air or water injection holes 29, as shown in Fig. 10 and 11, to facilitate the agitation of the liquefied limestone D in the limestone layer 19. In this case, it is possible to adjust the speed of stirring the limestone layer 19 caused by air or water in the zone of neutralization by changing the volume of air or water, to be issued in the neutralization area, instead of regulating the diameter of the particles of limestone D. Block diagram of the control algorithm used in this case, the same as in Fig. 12.

Horizontal tower desulfurization according to the present invention includes such towers, in which the flow of gas in the absorbing tower is aimed not only horizontally, as shown in Fig. 25, but slightly inclined in a non-vertical direction.

Example 11

The present invention is applicable also to the installation of flue gas desulfurization, equipped with an external tower oxidation, as shown in Fig. 26. This installation of obesserivaniya), the housing 1 of the desulfurization tower for spraying the absorbing liquid to react with SO2in the exhaust and the tower 45 oxidation for the oxidation semitecolo calcium formed in the housing 1 of the desulfurization tower. In the installation of desulphurization of flue gases, provided with outer tower oxidation in Fig. 25, following main reactions take place.

SO2the exhaust gas A is absorbed by the absorbing liquid (the main component of water) in the housing 1 of the desulfurization tower to the formation of the H2SO3, which then reacts with sanitarily calcium (CaSO31/2H2O) contained in the absorbing liquid, prior to the formation of hyposulphite of calcium (Ca(HSO3)2).

The hyposulphite of calcium reacts with the limestone in the area of neutralization by passing through the limestone layer 19 to the education semitecolo calcium. Thus obtained sanitarily calcium is again fed to the nozzles 4 and reacts with H2SO3, which is formed by absorption of SO2in the exhaust A. on the other hand, part semitecolo calcium supplied to the tank 46, where it is governed by its pH value by the addition of sulfuric acid G with shaking through mesh the PTA is oxidized to form gypsum (CaSO42H2O) using the formulas of chemical reactions:

(Reaction absorption) H2O + SO2= H2SO3;

CaSO31/2H2O + H2SO4= Ca(HSO3)2+ 1/2H2O.

(Neutralization reaction)

Ca(HSO3)2+ CaCO3= CaSO31/2H2O + CO2.

(Oxidation reaction) CaSO31/2H2O + 1/2O2+ 3/2H2O = CaSO42H2O

The block diagram of the control algorithm desulfurization tower according to this example is the same as in the first example. This example can also use the control according to the flowchart of the algorithm is shown in Fig. 14, the setting, which is illustrated in Fig. 10 and 11, using uduwela air or water 26, or that which is illustrated in Fig. 12, using air or water injection holes 29 for mixing the limestone layer 19.

As described above, according to the present invention, it is possible to obtain stable characteristics of the product, which is not reduced, even if changes in the circulating volume of the absorbing liquid. In addition, since it uses solid obesserivaniya substances that do not depend on the size reduction of particles, monarcho control the concentration of SO2in the exhaust at the outlet of the desulfurization tower in spite of load changes of the boiler or sulfur content in the fuel, so that the installation of desulfurization can be stable and less variable characteristic of desulfurization.

1. The method of wet flue gas desulfurization using obeserver substance, comprising contacting the exhaust gas produced from combustion appliances, such as a boiler, with the absorbing liquid, the neutralization of the absorbing fluid containing sulfur oxide absorbed from the exhaust gas through obeserver substances selectively left in the neutralization area, selective withdrawal from the zone of neutralization of the reaction product of sulfur oxide and an absorbing liquid containing water as a main component, contacting the absorbing fluid drained from the neutralization zone, with waste gas for absorption therein of sulfur oxide and the regulation of the output concentration of SO2in a given range of concentrations, characterized in that the output regulation of the concentration of SO2carried out by adjusting at least one parameter selected from the group of parameters vkluchaya, the amount of solid obeserver substances, be inserted in a fluid-absorbing particle diameter solid obeserver substances and the rate of mixing of solid obeserver substances in the zone of neutralization, by registering at least one parameter selected from the group of parameters including the load of the boiler, the sulfur content of fuel burned in the boiler, the flow rate of exhaust gas, the inlet concentration of SO2in the plant for desulfurization, the output concentration of SO2in the plant for desulfurization or the pH value of the absorbing liquid in the zone of neutralization or loss of pressure in the zone of neutralization, torque mixing device, the concentration of solids in the absorbing liquid specific gravity and viscosity of the absorbing liquid.

2. The method according to p. 1, characterized in that to calculate the volume obeserver substances necessary for regulating at least one parameter selected from the group of parameters including the flow rate of the absorbing fluid to circulation to ensure contact with exhaust gas, the amount of solid obeserver substances subject to introduction into the absorption liquid, the VA in the area of neutralization, whereby carry out the regulation of the output concentration of SO2installation for desulphurization in the given concentration range, determine the pressure loss in the neutralization zone, the solids concentrations of the absorbing liquid specific gravity or viscosity of the absorbing liquid.

3. The method according to p. 1 or 2, characterized in that for the liquefaction of solid obeserver substances form the upward flow of the absorbing liquid from the bottom zone of neutralization or form an upward flow of air or water from the bottom zone of neutralization together with the aforementioned upward flow of the absorbing liquid or independently, allowing control of stirring speed solid obeserver substances.

4. The method according to p. 3, characterized in that the neutralization area is divided into many compartments for independent formation of each branch of the upward flow of the absorbing liquid or upward flow of air or water, while the number of offices in which the solid is shaken obeserve substance is determined by the necessity of forming the upward flow of the absorbing liquid, air, or water in each of the Department is seriuose substances.

5. The method according to p. 1 or 2, characterized in that the amount of solid obeserver substance subject to the submission of a fluid-absorbing, adjust by adding solid obeserver substance with an average particle diameter of 100 μm or less.

6. The method according to p. 1 or 2, characterized in that the diameter of the solid particles obeserver substances remaining in the zone of neutralization, is 0.5 mm or more.

7. The method according to p. 1 or 2, characterized in that the solid obeserver substance use limestone, and the reaction product is gypsum.

8. Install wet flue gas desulfurization using obeserver substances, comprising a housing, a neutralization area for contacting exhaust gas produced from combustion appliances, such as a boiler, with the absorbing liquid and neutralizing absorbing fluid containing sulfur oxide absorbed in contact with waste gas, solid obesityvisit substance, intake pipe, exhaust pipe, means for selective withdrawal of absorbing fluid from the zone of neutralization, a channel for circulation of absorption liquid is selectively derived from the neutralization zone, medium, is about to feed solid obeserver substances, means for withdrawal of the reaction product with sulfur oxide and a means for mixing solid obeserver substances in the neutralization zone, characterized in that it is provided with means for registering at least one parameter selected from the group of parameters including the load of the boiler, the sulfur content of fuel burned in the boiler, the flow rate of exhaust gas, the input/output concentration of SO2in the plant for desulfurization or the pH value of the absorbing liquid in the zone of neutralization or loss of pressure in the zone of neutralization, torque mixers, solids concentrations of the absorbing liquid specific gravity and viscosity of the absorbing liquid, at least one means for the regulation of the parameters selected from the group including means to regulate such parameters as flow rate of the absorbing liquid circulating for contact with exhaust gas, the amount of solid obeserver substances subject to introduction into the absorption liquid, the diameter of the solid particles obeserver substances and the rate of mixing of solid obeserver substances in the zone of neutralization in accordance with the measured mentioned registration is bessarione in a given range of values.

9. Installation under item 8, characterized in that it contains a vertical channel exhaust gas from the lower inlet and upper outlet ends or non-vertical or horizontal channel of the exhaust gas.

 

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