Technical field
[0001]
The present disclosure relates to a gypsum slurry dewatering system for dewatering gypsum slurry by-produced in flue gas desulfurization equipment.
Background technology
[0002]
For example, exhaust gas discharged from a combustion engine such as a boiler contains air pollutants such as sulfur oxides (SOx), so sulfur oxides are removed from the exhaust gas in a flue gas desulfurization device before being released into the atmosphere. .
[0003]
As flue gas desulfurization equipment, wet flue gas desulfurization equipment using the lime-gypsum method is widely known. In a wet flue gas desulfurization system, the flue gas is brought into contact with limestone slurry (absorbing liquid), and the sulfur oxides (for example, sulfurous acid gas) in the flue gas are absorbed by the absorbing liquid, thereby removing sulfur oxides from the flue gas. are removing. The sulfur oxides absorbed in the absorbent react with calcium in the absorbent to form calcium sulfite, which is oxidized by the air supplied to the absorbent to form gypsum. Gypsum slurry (absorption liquid containing gypsum) is by-produced in wet flue gas desulfurization equipment.
[0004]
Patent Document 1 discloses that a slurry liquid containing gypsum slurry extracted from a wet flue gas desulfurization apparatus is subjected to solid-liquid separation in a gypsum separator to recover gypsum. Further, in Patent Document 1, a filter cloth is movably supported on a belt stretched between drums, and the gypsum slurry supplied onto the filter cloth is sucked from below the belt to separate the filtrate and the gypsum. A belt-type gypsum separator, a cleaning device for cleaning the filter cloth after discharging the gypsum slurry with a cleaning liquid, and a liquid storage tank for storing the cleaning liquid and the filtrate after cleaning the filter cloth are disclosed. The liquid stored in the liquid storage tank is sent to a wastewater treatment facility, and discharged outside the system after being treated in the wastewater treatment facility to meet the discharge standards.
prior art documents
patent literature
[0005]
Patent document 1: JP-A-8-12389
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0006]
As shown in Patent Document 1, the washing liquid and the filtrate after washing the filter cloth are collected in the same liquid storage tank and then sent to the wastewater treatment facility as wastewater. Since the above-described wastewater treatment equipment needs to treat a large amount of wastewater sent from the liquid storage tank, there is a risk that the size of the equipment will increase and the cost of the equipment will increase.
[0007]
In view of the circumstances described above, an object of at least one embodiment of the present disclosure is to reduce the amount of wastewater sent from a gypsum slurry dehydration treatment facility to a wastewater treatment facility, thereby reducing the size and cost of the wastewater treatment facility. To provide a gypsum slurry dehydration system capable of suppressing an increase in cost.
Means to solve problems
[0008]
The gypsum slurry dehydration system according to the present disclosure is
A gypsum slurry dewatering system for dewatering gypsum slurry discharged from flue gas desulfurization equipment,
a conveying device having a conveying belt that conveys the gypsum slurry placed on the filter cloth;
a filter cloth cleaning device having a jetting part capable of jetting a filter cloth cleaning liquid onto the filter cloth;
a filtrate storage tank configured to store the filtrate separated from the gypsum slurry by the filter cloth;
a filtrate discharge line configured to send the filtrate stored in the filtrate storage tank to a wastewater treatment facility that performs a process for discharging the filtrate out of the system;
a filter cloth cleaning liquid storage tank different from the filtrate storage tank, the filter cloth cleaning liquid storage tank configured to store at least the filter cloth cleaning liquid ejected from the ejection portion onto the filter cloth; Prepare.
Effect of the invention
[0009]
According to at least one embodiment of the present disclosure, it is possible to reduce the amount of wastewater sent from the gypsum slurry dehydration treatment equipment to the wastewater treatment equipment, thereby suppressing the increase in the size and cost of the wastewater treatment equipment. A gypsum slurry dewatering system is provided.
Brief description of the drawing
[0010]
1 is a schematic configuration diagram schematically showing the overall configuration of an exhaust gas cleaning system including a gypsum slurry dehydration system according to an embodiment of the present disclosure;
2 is a schematic configuration diagram schematically showing the overall configuration of a gypsum slurry dehydration system according to an embodiment of the present disclosure; FIG.
[Fig. 3] Fig. 3 is an explanatory diagram for explaining a wastewater treatment facility in an embodiment of the present disclosure.
4 is an explanatory diagram for explaining another example of the gypsum slurry dewatering system according to the embodiment of the present disclosure; FIG.
MODE FOR CARRYING OUT THE INVENTION
[0011]
Several embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiment or shown in the drawings are not meant to limit the scope of the present disclosure, but are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, expressions that express shapes such as squares and cylinders do not only represent shapes such as squares and cylinders in a geometrically strict sense, but also include irregularities and chamfers to the extent that the same effect can be obtained. The shape including the part etc. shall also be represented.
On the other hand, the expressions "comprising", "including", or "having" one component are not exclusive expressions that exclude the existence of other components.
In addition, the same reference numerals may be attached to the same configurations, and the description thereof may be omitted.
[0012]
(exhaust gas cleaning system)
FIG. 1 is a schematic configuration diagram schematically showing the overall configuration of an exhaust gas cleaning system equipped with a gypsum slurry dehydration system according to one embodiment of the present disclosure.
As shown in FIG. 1, a gypsum slurry dewatering system 1 according to some embodiments is mounted on an exhaust gas cleaning system 10. The exhaust gas cleaning system 10, as shown in FIG. and the gypsum slurry dewatering system 1 for dewatering the gypsum slurry.
[0013]
The flue gas desulfurization device 20 brings the exhaust gas discharged from the combustion equipment 11 into contact with the absorbing liquid to absorb sulfur oxides (for example, sulfurous acid gas) in the exhaust gas into the absorbing liquid, thereby removing sulfur from the exhaust gas. configured to remove objects. In the flue gas desulfurization apparatus 20 using the limestone gypsum method, for example, a slurry liquid containing an alkaline component such as limestone slurry in which limestone is dissolved (dispersed) is used as the absorbing liquid, and gypsum slurry (absorbing liquid containing gypsum) is by-produced. be done. Slurry is not strictly a liquid, but is treated as a liquid in this specification for the sake of convenience.
[0014]
The flue gas desulfurization device 20 includes an absorption tower 20A configured to desulfurize the flue gas introduced therein. The absorption tower 20A includes an absorption tower main body 22 configured to define an internal space 21 into which the exhaust gas discharged from the combustion equipment 11 is introduced, and an exhaust gas introduction port 23 for introducing the exhaust gas into the internal space 21. and an exhaust gas outlet 24 for discharging exhaust gas from the interior space 21 . Each of the flue gas inlet 23 and the flue gas outlet 24 communicates with the absorption tower main body 22 .
[0015]
The internal space 21 is positioned below the gas-liquid contact portion 21A and the gas-liquid contact portion 21A for bringing the exhaust gas and the absorbing liquid into gas-liquid contact. , sulfurous acid gas) is stored.
[0016]
The exhaust gas discharged from the combustion equipment 11 is introduced into the internal space 21 through the exhaust gas introduction port 23 . The exhaust gas led to the internal space 21 is washed by the absorbent when flowing upward in the internal space 21 and passing through the gas-liquid contact portion 21A, thereby removing sulfur oxides and the like in the exhaust gas. The exhaust gas after cleaning in the gas-liquid contact portion 21A is discharged to the outside of the absorption tower 20A through the exhaust gas discharge port 24 as a purified gas, which is the purified exhaust gas. The purified gas discharged to the outside of the absorption tower 20A is released into the atmosphere from a chimney (not shown) provided downstream of the exhaust gas outlet 24 in the flow direction of the purified gas (exhaust gas). As shown in FIG. 1, a mist eliminator 25 configured to remove moisture from the purified gas (exhaust gas) may be provided downstream of the gas-liquid contact portion 21A in the flow direction of the purified gas (exhaust gas). good.
[0017]
In the illustrated embodiment, the absorption tower 20A further includes a spray device 26 arranged in the gas-liquid contact section 21A. The spray device 26 is configured to spray an absorption liquid (limestone slurry) onto the exhaust gas passing through the gas-liquid contact portion 21A. The absorbent sprayed from the spray device 26 comes into contact with the exhaust gas and absorbs and removes sulfur oxides (for example, sulfurous acid gas) contained in the exhaust gas.
[0018]
The spray device 26 includes a spray pipe 261 extending in a horizontal direction that intersects the flow direction of the exhaust gas, and a plurality of spray nozzles 262 provided on the spray pipe 261 . As shown in FIG. 1, the spray nozzle 262 has a spray port 263 that sprays the absorbing liquid downstream in the flow direction of the exhaust gas, ie, upward in the vertical direction. Note that, in some other embodiments, the spray nozzle 262 may have a spray port that sprays the absorbing liquid downward in the vertical direction.
[0019]
In the liquid pool portion 21B, the absorbent is sprayed from the spray port 263 of the spray nozzle 262 to the exhaust gas guided to the internal space 21, and the absorbent that has absorbed and removed the sulfur oxides contained in the exhaust gas falls and is stored. . The absorbent stored in the liquid pool 21B may contain sulfites produced from sulfur oxides absorbed from the exhaust gas and gypsum (calcium sulfate) produced by oxidation of sulfites.
[0020]
The absorption tower main body 22 has an absorbent extraction port 221 for extracting the absorbent stored in the liquid pool 21B to the outside, and an oxidizing gas (for example, air) to the absorbent stored in the liquid pool 21B. A nozzle through-hole 222 through which a nozzle for supplying is passed is open. Each of the absorbent outlet 221 and the nozzle through-hole 222 communicates with the liquid pool portion 21B. The absorber main body 22 is also provided with an absorbent supply port 223 for introducing the limestone slurry and an absorbent return port 224 for returning the extracted absorbent to the pool portion 21B. Each of the absorbent supply port 223 and the absorbent return port 224 communicates with the internal space 21 above the liquid pool portion 21B.
[0021]
The absorption tower 20A further includes an oxidizing gas supply device 27 configured to supply an oxidizing gas (for example, air) to the absorbent stored in the liquid pool 21B. In the illustrated embodiment, the oxidizing gas supply device 27 includes a nozzle 271 passing through the nozzle through-hole 222 and a pump 272 supplying atmospheric air to the nozzle 271 . Atmospheric air (oxidizing air) is supplied to the nozzle 271 by a pump 272, and is supplied to the absorbent stored in the liquid pool 21B through an opening 273 at the tip of the nozzle. As a result, the sulfite in the absorbing liquid stored in the liquid pool portion 21B can be oxidized to produce gypsum.
[0022]
The absorption tower 20A includes an absorption liquid supply line 12 configured to supply the absorption liquid to the liquid pool portion 21B of the absorption tower 20A, and an absorption liquid extracted from the liquid pool portion 21B so as to be sent to the spray device 26. It further includes a configured absorbent circulation line 13 and an absorbent extraction line 14 configured to send the absorbent extracted from the liquid pool 21B to the gypsum slurry dehydration system 1 . The absorption tower 20A circulates the absorbent through the spray device 26, the liquid reservoir 21B and the absorbent circulation line 13. Since the absorbent stored in the liquid pool 21B is repeatedly used for cleaning the exhaust gas in the absorption tower 20A, it graduallyGypsum accumulates on By sending the gypsum slurry (absorbing liquid containing gypsum) to the gypsum slurry dewatering system 1 through the absorbing liquid extraction line 14, the absorbing liquid circulation system (spraying device 26, liquid pool 21B, absorbing liquid circulation line 13). gypsum is extracted from In addition, in order to achieve both the absorption and removal of sulfur oxides in the exhaust gas by the absorbing liquid (the higher the pH, the better the efficiency) and the oxidation of the sulfite in the absorbing liquid (the lower the pH, the better the efficiency), The absorption liquid is appropriately supplied through the absorption liquid supply line 12 so that the pH of the absorption liquid is in the range of 5-6.
[0023]
In the illustrated embodiment, the absorbent supply line 12 terminates at one end in an absorbent reservoir 17 arranged outside the absorber tower 20A and configured to define an internal space 171 for storing the absorbent. and an absorbent supply pipe 121 connected at the other end to an absorbent supply port 223, and an absorbent supply pipe 121 provided in the absorbent supply pipe 121 to send the absorbent from one end of the absorbent supply pipe 121 to the other end. and a feed pump 122 configured to. By driving the supply pump 122, the absorption liquid is extracted from the internal space 171 and supplied to the liquid pool 21B of the absorption tower 20A.
[0024]
In the illustrated embodiment, the absorbent circulation line 13 is provided with an absorbent circulation pipe 131 having one end connected to the absorbent outlet 221 and the other end connected to the spray pipe 261, and the absorbent circulation pipe 131. and a circulation pump 132 configured to send the absorbent from one end of the absorbent circulating pipe 131 to the other end. One end of the absorbent extracting line 14 is connected to a first branch 133 located on the downstream side (spraying device 26 side) of the absorbent circulating pipe 131 in the direction of flow of the absorbent relative to the circulation pump 132, and the other end is connected to gypsum. It includes an absorbent extraction pipe 141 connected to the slurry dehydration system 1 (specifically, the supply device 4 shown in FIG. 2). In this case, the absorbent circulation line 13 and the absorbent withdrawal line 14 share the circulation pump 132 . By driving the circulation pump 132 , the absorbent is extracted from the liquid pool 21B and supplied to the spray device 26 and the gypsum slurry dehydration system 1 . In some other embodiments, the absorbent extraction line 14 may be configured so as not to have a shared portion with the absorbent circulation line 13 .
[0025]
In the illustrated embodiment, the absorbent withdrawal line 14 further includes a regulating valve 142 provided on the other end side of the absorbent withdrawal pipe 141 . The regulating valve 142 has a movable mechanism for opening and closing the absorbent withdrawal pipe 141, which is the flow path of the absorbent, and controls the flow rate of the absorbent flowing through the absorbent withdrawal pipe 141 and supplied to the gypsum slurry dehydration system 1. configured to be adjustable.
[0026]
The absorption tower 20A further includes an absorbent return line 15 for returning the absorbent from the absorbent extraction line 14 to the liquid reservoir 21B of the absorption tower 20A. One end of the absorbent return line 15 is connected to a second branch 143 located upstream (first branch 133 side) in the flow direction of the absorbent from the regulating valve 142 of the absorbent extraction pipe 141, and the other end is connected to the second branch 143. It includes an absorbent return pipe 151 whose side is connected to the absorbent return port 224 . At least part of the absorbent flowing through the absorbent withdrawal pipe 141 is pressure-fed by the circulation pump 132 and returned to the absorption tower 20A via the absorbent return pipe 151 . Even if the amount of absorbent supplied to the gypsum slurry dehydration system 1 is small, a larger amount of absorbent than the necessary supply to the gypsum slurry dehydration system 1 is allowed to flow through the absorbent withdrawal pipe 141 to absorb the surplus. By returning the liquid to the absorption tower 20A through the absorbent return pipe 151, the flow rate of the absorbent (gypsum slurry) in the absorbent extraction pipe 141 is maintained at a predetermined speed or higher, and the solid content in the absorbent (for example, , gypsum, etc.) can be suppressed from settling in the absorbent extraction pipe 141 .
[0027]
(gypsum slurry dehydration system)
FIG. 2 is a schematic configuration diagram schematically showing the overall configuration of the gypsum slurry dehydration system according to one embodiment of the present disclosure.
The gypsum slurry dehydration system 1 according to some embodiments is configured to dehydrate the gypsum slurry (absorption liquid containing gypsum) sent from the absorption tower 20A through the absorption liquid extraction pipe 141 and separate it into gypsum and filtrate. It is
[0028]
As shown in FIG. 2, the gypsum slurry dehydration system 1 includes a conveying device 3 having a conveying belt 32 that conveys the gypsum slurry on the filter cloth 31, and the gypsum slurry on the filter cloth 31 of the conveying belt 32. and a cake washing liquid can be jetted toward the gypsum cake in order to wash the gypsum cake formed on the filter cloth 31 while the gypsum slurry is dehydrated and conveyed. and a steam jetting device 54 having a steam jetting portion 55 (jetting portion) capable of jetting drying steam. Each of the supply portion 41 , the cake cleaning liquid ejection portion 45 and the steam ejection portion 55 is arranged above the conveying belt 32 . The cake cleaning liquid jetting portion 45 is located downstream of the feeding portion 41 in the direction along the transporting direction of the conveying belt 32 (right side in FIG. is located on the downstream side in the direction along the conveying direction.
[0029]
In the illustrated embodiment, the conveying device 3 is connected to two rotatably supported drums 33 (33A, 33B) and one of the two drums 33 (for example, 33A). It further has a motor 34 configured to rotationally drive the drum 33 (33A), and a plurality of guide rollers 35 . The conveying belt 32 is made of an endless belt-like rubber member (elastic body), and is stretched around two drums 33 that are horizontally spaced from each other so as to be able to travel. Since the conveying belt 32 is stretched between the two drums 33, when the motor 34 rotates the drum 33 (33A), the other drum 33 (33B) rotates, and the conveying belt 32 rotates. 32 circulates along the conveying direction of the conveying belt 32 .
[0030]
The filter cloth 31 is provided in the shape of an endless belt, and is stretched around a plurality of guide rollers 35 so as to be free to travel, and a part of the length direction thereof is overlapped on the upper surface 321 of the conveying belt 32 . A portion of the filter cloth superimposed on the upper surface 321 of the conveying belt 32 (hereinafter referred to as a supported portion 311) is supported by the conveying belt 32 so as to freely travel along the conveying direction together with the conveying belt 32 . For this reason, when the drum 33 (33A) is rotationally driven and the transport belt 32 is circulated, the supported portion 311 of the filter cloth 31 moves together with the support portion 322 that supports the supported portion 311 of the transport belt 32 from below. , along the conveying direction. In one embodiment, the filter cloth 31 includes a woven cloth formed by weaving a fibrous resin material (eg, polyester, polypropylene, etc.). In another embodiment, the filter cloth 31 includes a nonwoven fabric formed by entangling fibrous resin materials (eg, polyester, polypropylene, etc.).
[0031]
The supply device 4 is configured to supply the gypsum slurry sent from the absorption tower 20A through the absorbent extraction line 14 from its supply portion 41 onto the filter cloth 31 of the conveyor belt 32 . In the illustrated embodiment, the supply device 4 has one end connected to the supply part 41 (e.g., injection nozzle) and the other end of the absorbent extracting pipe 141, and the other end connected to the supply part 41. and a supply pipe 42 . In this case, the gypsum slurry is pressure-fed by the circulation pump 132 described above, passes through the supply pipe 42 , and flows down from the supply section 41 to be supplied onto the filter cloth 31 of the conveyor belt 32 . Strictly speaking, “on the filter cloth 31 of the conveying belt 32 ” means on the upper surface (outer surface) 312 of the supported portion 311 of the filter cloth 31 .
[0032]
The gypsum slurry is placed on the filter cloth 31 of the conveying belt 32 and is dewatered when conveyed together with the filter cloth 31 by the conveying belt 32 . A dewatering section 36 is defined as a region in the conveying device 3 where the gypsum slurry is dewatered. In the dewatering section 36 , the transport belt 32 is positioned above the drum 33 , and the supported portion 311 of the filter cloth 31 is supported by the support portion 322 of the transport belt 32 . Each of the supply section 41 , the cake cleaning liquid ejection section 45 and the steam ejection section 55 described above is arranged within the region of the dewatering section 36 .
[0033]
The filter cloth 31 has air permeability, and the conveying belt 32 is formed with a plurality of holes for passing the filtrate. The gypsum slurry placed on the filter cloth 31 of the conveying belt 32 is dewatered in the dewatering section 36 as the filtrate passes through the filter cloth 31 and the conveying belt 32 .
[0034]
In the illustrated embodiment, the conveying device 3 further has a dewatering device 37 configured to suck the gypsum slurry placed on the filter cloth 31 from below and dewater the filtrate. The dehydrator 37 is provided below the support portion 322 of the conveyor belt 32 and includes a dehydration chamber 371 whose internal pressure is maintained at a negative pressure (pressure lower than atmospheric pressure), a vacuum pump 372, and the dehydration chamber 371. and a vacuum tank 374 provided in the decompression pipe 373 . By driving the vacuum pump 372, the pressure in the dewatering chamber 371 is reduced to a negative pressure, and the water in the gypsum slurry placed on the filter cloth 31 is forcibly sucked from below, and the gypsum slurry is dewatered.
[0035]
Moisture (filtrate) sucked by the vacuum pump 372 and sent from the dehydration chamber 371 to the vacuum tank 374 is connected to the lower end of the vacuum tank 374 at one end side and the other end side is a liquid discharge pipe extending downward. 375 and flows down to the filtrate reservoir 6 configured to hold the filtrate.
[0036]
The gypsum slurry that is placed on the filter cloth 31 and transported is dehydrated as it is transported to the transport belt 32 and becomes a cake. In the illustrated embodiment, the cake cleaning device 44 has one end connected to the cake cleaning liquid jetting part 45 (e.g., jet nozzle) and the cake cleaning liquid jetting part 45, and the other end connected to a cleaning liquid tank (not shown). and a pump 47 provided in the cake cleaning liquid supply pipe 46 . By driving the pump 47, the cleaning liquid is sent from the cleaning liquid tank to the cake cleaning liquid ejection section 45, and is ejected from the cake cleaning liquid ejection section 45 toward the gypsum slurry (cake) on the filter cloth located below. The gypsum slurry (cake) is washed with a washing liquid to remove impurities (eg, metal ions such as magnesium (Mg), chlorine (Cl), and sodium (Na)). Examples of the cake washing liquid include industrial water. The cake washing liquid used for washing the cake is sucked by the dehydrator 37, passes through the filter cloth 31 and the conveying belt 32, is sent as filtrate from the dehydration chamber 371 to the vacuum tank 374, and flows through the liquid discharge pipe 375. and flows down to the filtrate storage tank 6 .
[0037]
In the illustrated embodiment, drying steam is sent from a steam pipe 56 connected to a boiler (not shown) to a steam ejection part 55 (e.g., an injection nozzle) of the steam ejection device 54, and is located below the steam ejection part 55. It is jetted toward the gypsum slurry on the filter cloth 31 . Moisture contained in the gypsum slurry on the filter cloth 31 is removed by heating with drying steam.
[0038]
In the illustrated embodiment, the gypsum obtained by dewatering the gypsum slurry on the filter cloth 31 in the dewatering section 36 is distributed downstream of the dewatering section 36 (for example, the steam ejection section 55) in the conveying direction of the conveying belt 32. , is removed from the filter cloth 31 . A gypsum discharge portion 43 is defined as a region of the conveying device 3 where the gypsum is removed from the filter cloth 31 .
[0039]
As shown in FIG. 2 , the gypsum slurry dehydration system 1 includes a filter cloth cleaning liquid jetting section 51 capable of jetting the filter cloth cleaning liquid onto the filter cloth 31 downstream of the gypsum discharging section 43 in the conveying direction of the conveyor belt 32 . A filter cloth cleaning device 5 havingI get it. In the illustrated embodiment, the filter cloth cleaning device 5 includes the filter cloth cleaning liquid jetting portion 51 (e.g., jet nozzle) disposed below the two drums 33 and one end of the filter cloth cleaning liquid jetting portion 51. It has a filter cloth cleaning liquid supply pipe 52 connected and the other end connected to a cleaning liquid tank (not shown), and a pump 53 provided in the filter cloth cleaning liquid supply pipe 52 . By driving the pump 53 , the cleaning liquid is sent from the cleaning liquid tank to the filter cloth cleaning liquid jetting portion 51 and jetted from the filter cloth cleaning liquid jetting portion 51 toward the filter cloth 31 . Impurities are removed from the filter cloth 31 by washing with the washing liquid. Examples of the filter cloth washing liquid include industrial water. The filter cloth cleaning liquid is jetted toward at least one of the outer surface and the inner surface of the filter cloth 31 .
[0040]
The gypsum slurry dehydration system 1, for example, as shown in FIG. 2, has a filter cloth washing liquid receiving portion 58 (for example, a tray) provided below the filter cloth washing liquid ejection portion 51, and one end side is connected to the filter cloth washing liquid receiving portion 58. and a filter cloth washing liquid discharge pipe 59 having the other end extending downward. The filter cloth cleaning liquid ejected from the filter cloth cleaning liquid ejecting portion 51 drops onto the filter cloth cleaning liquid receiving portion 58 . The filter cloth washing liquid that has fallen onto the filter cloth washing liquid receiver 58 passes through the filter cloth washing liquid discharge pipe 59 and flows down to the filter cloth washing liquid storage tank 8 configured to store the filter cloth washing liquid.
[0041]
In the illustrated embodiment, the gypsum slurry dewatering system 1 is arranged outside the absorber tower 20A and includes the filtrate storage tank 6 configured to define an internal space 61 for storing the filtrate. , the filter cloth washing liquid storage tank 8 arranged outside the absorption tower 20A and configured to define an internal space 81 for storing the filter cloth washing liquid, and the filtrate stored in the filtrate storage tank 6 is sent to a waste water treatment facility 16 for discharging the filtrate out of the system, and the liquid stored in the filter cloth cleaning liquid storage tank 8 is combined with the above-mentioned absorbent a water line 9 configured to feed the reservoir 17; That is, the liquid (filtrate) stored in the filtrate storage tank 6 is discharged outside the system after being sent to the wastewater treatment facility 16, and the liquid (including the filter cloth cleaning liquid) stored in the filter cloth cleaning liquid storage tank 8 liquid) is sent to the absorbent storage tank 17, mixed with limestone supplied through a supply line (not shown), and sent to the absorption tower 20A as the absorbent.
[0042]
The gypsum slurry dewatering system 1 according to some embodiments, as shown in FIG. The filter cloth washing device 5 having the filter cloth washing liquid jetting portion 51 (jetting portion) capable of jetting the filter cloth washing liquid to the filter cloth 31, and the filter cloth washing device 5 configured to store the filtrate separated from the gypsum slurry by the filter cloth 31. The filtrate storage tank 6, the above-described filtrate discharge line 7 configured to be sent to the wastewater treatment facility 16 that performs a treatment for discharging the filtrate stored in the filtrate storage tank 6 to the outside of the system, and the filtrate A filter cloth cleaning liquid storage tank 8 different from the liquid storage tank 6 is configured to store at least the filter cloth cleaning liquid ejected from the filter cloth cleaning liquid ejecting portion 51 (jetting portion) onto the filter cloth 31. and a filter cloth washing liquid storage tank 8 .
[0043]
The gypsum slurry discharged from the flue gas desulfurization device 20 absorbs impurities from the flue gas in the flue gas desulfurization device 20 (for example, suspended matter such as combustion ash and soot removed from the flue gas, pollutants such as dissolved heavy metals, etc.). is doing. Then, the impurities are separated from the gypsum together with the filtrate from the gypsum slurry in the dehydration equipment (for example, the conveying device 3, etc.). In addition, the cake washing liquid used for washing the cake contains impurities such as metal ions such as magnesium (Mg), chlorine (Cl) and sodium (Na). For this reason, the cake washing liquid sent to the filtrate storage tank as the filtrate after washing the filtrate and the cake separated from the gypsum slurry is compared with the filter cloth washing liquid jetted onto the filter cloth 31. , with a high content of impurities. Returning the filtrate with a high impurity content to the circulation system of the absorbent in the flue gas desulfurization apparatus 20 is not appropriate because the impurity content in the absorbent in the flue gas desulfurization apparatus 20 increases. The filtrate having a high content of impurities is preferably discharged outside the system after the wastewater treatment in the wastewater treatment equipment 16 .
[0044]
According to the above configuration, the filtrate separated from the gypsum slurry and the cake washing liquid used for washing the cake can be stored in the filtrate storage tank 6, and the filter cloth washing liquid jetted onto the filter cloth 31 can be filtered. It can be stored in the cloth cleaning liquid storage tank 8 . Then, the filtrate stored in the filtrate storage tank 6 can be sent to the wastewater treatment facility 16 through the filtrate discharge line 7 and discharged outside the system after the wastewater treatment in the wastewater treatment facility 16 . In this way, the filtrate with a high impurity content rate and the filter cloth washing liquid with a low impurity content rate are separately stored, and the waste water sent to the waste water treatment facility 16 is treated as the impurities stored in the filtrate storage tank 6. By limiting the filtrate to a high-content filtrate, the amount of wastewater sent from the gypsum slurry dehydration treatment equipment to the wastewater treatment equipment 16 can be reduced by the amount of the filter cloth washing liquid. In addition, by reducing the amount of wastewater sent to the wastewater treatment facility 16, it is possible to suppress the increase in the size of the wastewater treatment facility 16 and the increase in equipment costs.
[0045]
In some embodiments, as shown in FIG. 2, the above-described filtrate storage tank 6 is configured such that, of the filtrate stored in the filtrate storage tank 6, the filtrate exceeding a predetermined height H1 is the filter cloth. It is configured to overflow into the cleaning liquid storage tank 8 .
[0046]
In the illustrated embodiment, as shown in FIG. 2, the filtrate storage tank 6 has an inner side surface 62 and a bottom surface 63 in the shape of a rectangular tube. The internal space 61 is defined by an inner side surface 62 and a bottom surface 63 . The filter cloth washing liquid storage tank 8 has an inner side surface 82 and a bottom surface 83 in the shape of a rectangular tube. The internal space 81 is defined by an inner side surface 82 and a bottom surface 83 . In the embodiment shown in FIG. 2 , the bottom surface 83 of the filter cloth washing liquid reservoir 8 is configured to be at the same height as the bottom surface 63 of the filtrate reservoir 6 . The filtrate storage tank 6 is arranged adjacent to the filter cloth cleaning liquid storage tank 8 with a weir 64 interposed therebetween. The weir 64 stands vertically upward from the bottom surface 63 and has one surface 62A of the inner side surfaces 62 on one side and one surface 82A of the inner side surfaces 82 on the other side. have in In this case, among the filtrate stored in the filtrate storage tank 6, the filtrate exceeding the height of the upper end of the weir 64, which is the predetermined height H1, exceeds the weir 64 and reaches the filter cloth washing liquid storage tank 8. flow into. In some other embodiments, instead of the weir 64, one end side is connected to the above-mentioned predetermined height position of the filtrate storage tank 6, and the other end side is connected to the above-mentioned predetermined height position of the filter cloth washing liquid storage tank 8. An overflow pipe may be provided which is connected to a lower position than the upper position.
[0047]
According to the above configuration, the filtrate storage tank 6 is arranged such that, of the filtrate stored in the filtrate storage tank 6, the filtrate exceeding the predetermined height H1 overflows the filter cloth washing liquid storage tank 8. It is configured. Therefore, the filtrate other than the predetermined amount of filtrate that needs to be sent to the wastewater treatment facility 16 can be sent to the filter cloth washing liquid storage tank 8 without using complicated equipment such as a pump and level control. It is possible to suppress the complication and increase in cost of equipment.
Further, for example, even when the filtrate is supplied to the filtrate storage tank 6 in excess of the amount that can be treated by the wastewater treatment equipment 16, the filtrate storage tank 6 supplies only the amount that can be treated to the wastewater treatment equipment 16. If the filtrate is sent, the remaining filtrate exceeding the treatable amount naturally overflows into the filter cloth washing liquid storage tank 8 and is stored in the filter cloth washing liquid storage tank 8, so that wastewater treatment The equipment 16 does not need to be large enough, and the increase in cost of the wastewater treatment equipment 16 can be suppressed.
[0048]
In some embodiments, the above-described filtrate discharge line 7 includes a drain pipe 71 connected to the above-described filtrate storage tank 6 and the above-described waste water treatment facility 16, and a drain pump 72 provided in the drain pipe 71. , and a flow rate adjustment valve 73 provided downstream of the drainage pump 72 in the drainage pipe 71 and capable of adjusting the flow rate of the filtrate sent from the filtrate storage tank 6 to the drainage treatment facility 16 .
[0049]
FIG. 3 is an explanatory diagram for explaining the wastewater treatment facility in one embodiment of the present disclosure.
As shown in FIG. 3, the wastewater treatment facility 16 has an internal space 162 configured to store wastewater, a first coagulating sedimentation tank 161 in which coagulating sedimentation treatment is performed, and a It includes at least a second coagulation-sedimentation tank 163 having a configured internal space 164 and in which coagulation-sedimentation treatment is performed. The second coagulating sedimentation tank 163 is provided downstream of the first coagulating sedimentation tank 161 in the flow direction of the waste water.
[0050]
The waste water treatment facility 16 includes a first coagulant addition line 165 configured to add a coagulant to the first coagulant sedimentation tank 161 and a second coagulant added line 165 configured to add a coagulant to the second coagulant sedimentation tank 163. 2 flocculant addition line 166; A coagulant (for example, an aluminum compound such as aluminum sulfate) is added to the first coagulant-sedimentation tank 161 through the first coagulant addition line 165, so that flocs of aluminum hydroxide are precipitated in the waste water and removed from the exhaust gas. Impurities such as suspended matter such as combustion ash and soot, and contaminants such as dissolved heavy metals are included in the flocs and precipitate. A coagulant (for example, sodium carbonate) is added to the second coagulant sedimentation tank 163 through the second coagulant addition line 166, so that flocs of calcium carbonate are precipitated in the waste water, and suspended matter and the like are deposited in the flocs. included and precipitated. A pH adjuster may also be added to the first coagulating sedimentation tank 161 and the second coagulating sedimentation tank 163 .
[0051]
The first coagulating sedimentation tank 161 is connected downstream of the flow rate adjustment valve 73 of the drainage pipe 71 , and drainage (filtrate) is sent from the filtrate storage tank 6 via the drainage pipe 71 . In the first coagulation-sedimentation tank 161, among the waste water stored in the first coagulation-sedimentation tank 161, the waste water that has undergone the condensation treatment in the first coagulation-sedimentation tank 161, and the waste water that exceeds the predetermined height H2 is It is configured to overflow into the second coagulating sedimentation tank 163 .
[0052]
In the illustrated embodiment, the first coagulation-sedimentation tank 161 has a weir 167 provided between it and a second coagulation-sedimentation tank 163 arranged adjacent to the first coagulation-sedimentation tank 161. and a partition 168 provided on the upstream side in the flow direction. The partition 168 hangs below the upper end of the weir 167, so that the first coagulating sedimentation tank 161 is separated from one side into which waste water is introduced from the drainage pipe 71 and the other side with the partition 168 interposed therebetween. and the other side. On the other side of the first coagulating-sedimentation tank 161, wastewater mainly subjected to coagulation-sedimentation treatment in the first coagulation-sedimentation tank 161 is stored. In this case, out of the liquid stored on the other side of the first coagulating sedimentation tank 161, the waste water exceeding the height of the upper end of the weir 167, which is the predetermined height H2, exceeds the weir 167 and reaches the first level. 2 It flows into the coagulation sedimentation tank 163 . The wastewater treatment facility 16 includes an impurity removal mechanism (not shown) configured to remove flocs that have settled in the first coagulation-sedimentation tank 161 and the second coagulation-sedimentation tank 163 . Also, in some other embodiments, an overflow pipe may be provided in place of the weir 167 described above.
[0053]
In the wastewater treatment facility 16, when the amount of wastewater sent to each tank such as the first coagulating sedimentation tank 161 and the second coagulating sedimentation tank 163 is large, the wastewater is sent downstream before impurities are sufficiently removed in each tank. Therefore, there is a risk that wastewater treatment will be insufficient. For this reason, the filtrate discharge line 7 described above preferably sends the amount of filtrate to the wastewater treatment equipment 16 according to the treatment performance of the wastewater treatment equipment 16 .
[0054]
According to the above configuration, the filtrate discharge line 7 includes a drain pipe 71 connected to the filtrate storage tank 6 and the waste water treatment facility 16, a drain pump 72 provided in the drain pipe 71, and a drain pump 72 in the drain pipe 71. , the flow rate of the filtrate sent from the filtrate storage tank 6 to the waste water treatment facility 16 via the drain pipe 71 can be adjusted. Therefore, the filtrate discharge line 7 isAn amount of filtrate corresponding to the treatment performance of the water treatment facility 16 can be sent to the wastewater treatment facility 16 .
[0055]
In some embodiments, the above-described gypsum slurry dehydration system 1 includes the above-described absorbent storage tank 17 configured to store the absorbent that is brought into gas-liquid contact with the exhaust gas in the flue gas desulfurization apparatus 20, and the filter cloth cleaning liquid. and a water supply line 9 configured to send the liquid stored in the reservoir 8 to the absorbent reservoir 17 .
[0056]
Since the amount of impurities adhering to the filter cloth 31 after gypsum discharge is small, the filter cloth washing liquid has a low impurity content even if it absorbs the impurities adhering to the filter cloth 31 . Filtrate with a high content of impurities may overflow from the filtrate storage tank 6 into the filter cloth cleaning liquid storage tank 8, but it is diluted by the filter cloth cleaning liquid, so it is stored in the filter cloth cleaning liquid storage tank 8. The liquid has a lower impurity content than the filtrate stored in the filtrate storage tank 6 . According to the above configuration, by sending the liquid stored in the filter cloth cleaning liquid storage tank 8 with a low impurity content rate to the absorbent storage tank 17 via the water supply line 9, the liquid is transferred to the flue gas desulfurization apparatus 20. It can be returned to the circulation system of the absorbing liquid in and reused as the absorbing liquid.
[0057]
In some embodiments, as shown in FIG. 2, the above-described water supply line 9 includes a water supply pipe 91 connected to the above-described filter cloth washing liquid storage tank 8 and the above-described absorbent storage tank 17, and a water supply pipe. and a water pump 92 provided at 91 . The water pump 92 is configured such that its rotation speed is controlled according to the liquid level height H3 of the liquid stored in the filter cloth washing liquid storage tank 8 .
[0058]
In the illustrated embodiment, as shown in FIG. 2, the gypsum slurry dehydration system 1 described above is configured to acquire the liquid level height H3 of the liquid stored in the filter cloth cleaning liquid storage tank 8. A control device including a surface height acquisition device 93 and a rotation speed instruction unit 941 configured to instruct a rotation speed to the water pump 92 according to the liquid level height H3 acquired by the liquid level acquisition device 93. 94 and .
[0059]
An example of the liquid level acquisition device 93 is an infrared liquid level sensor. The control device 94 is an electronic control unit for adjusting the rotation speed of the water pump 92, and includes a CPU (processor) (not shown), memories such as ROM and RAM, storage devices such as external storage devices, I/O interfaces, and communication. It may be configured as a microcomputer including an interface and the like. Each functional unit is implemented by the CPU operating (for example, calculating data) according to the instructions of the program loaded in the main storage device of the memory, for example. The control device 94 is configured to be able to transmit and receive signals to and from the water pump 92 and the liquid level acquisition device 93 . The water pump 92 is electrically controlled by a signal sent from the control device 94, and is configured to be driven or stopped according to the signal, and to be able to adjust its rotation speed. As such a water pump 92, for example, a water pump incorporating an inverter motor or the like can be used.
[0060]
In the illustrated embodiment, the rotation speed instruction unit 941 instructs the water pump 92 to stop when the liquid level height H3 sent from the liquid level acquisition device 93 is less than the lower limit threshold value LH. . Further, in a state where the water pump 92 is stopped, the rotation speed instruction unit 941 drives the water pump 92 when the liquid level height H3 sent from the liquid level height acquisition device 93 is equal to or higher than the lower limit threshold value LH. instruct to do so. Further, when the liquid level height H3 sent from the liquid level acquisition device 93 is equal to or lower than the upper limit threshold value UH and equal to or higher than the lower limit threshold value LH, the rotation speed instruction unit 941 causes the water pump 92 to rotate at the first rotation speed. Instruct to rotate by When the liquid level H3 sent from the liquid level acquisition device 93 exceeds the upper limit threshold value UH, the rotation speed instruction unit 941 causes the water pump 92 to rotate at a second rotation speed higher than the first rotation speed. Instruct to rotate. The upper limit threshold UH is set lower than a predetermined height H1 (the height of the upper end of the weir 64).
Note that, in some other embodiments, the rotation speed instruction unit 941 continuously or stepwise instructs the water pump 92 to rotate as the liquid level height H3 sent from the liquid level acquisition device 93 increases. It may be configured to increase the number.
[0061]
Since not only the filter cloth cleaning liquid but also the filtrate overflowing from the filtrate storage tank 6 is sent to the filter cloth cleaning liquid storage tank 8, the liquid level of the liquid stored in the filter cloth cleaning liquid storage tank 8 suddenly rises. There is a risk that the liquid will overflow from the filter cloth washing liquid storage tank 8 due to a large rise. According to the above configuration, the water supply line 9 includes a water supply pipe 91 connected to the filter cloth washing liquid storage tank 8 and the absorbent storage tank 17 , and a water supply pump 92 provided in the water supply pipe 91 . The water pump 92 is configured such that its rotation speed is controlled according to the level of the liquid stored in the filter cloth washing liquid storage tank 8 . In this case, the rotation speed of the water pump 92 is controlled so that the level of the liquid stored in the filter cloth cleaning liquid storage tank 8 does not become excessively high. overflow can be suppressed.
[0062]
FIG. 4 is an explanatory diagram for explaining another example of the gypsum slurry dewatering system according to one embodiment of the present disclosure.
In some embodiments, as shown in FIG. 4, the above-described water supply line 9 is provided in the above-described water supply pipe 91, a water supply pump 92 provided in the water supply pipe 91, and a filter. and a flow control valve 95 configured to adjust the flow rate of liquid sent from the fabric cleaning liquid reservoir 8 to the absorbent reservoir 17 . The flow rate control valve 95 is configured such that its opening degree is controlled according to the liquid level height H3 of the liquid stored in the filter cloth cleaning liquid storage tank 8 . In this case, the rotation speed of the water pump 92 is kept constant.
[0063]
In the illustrated embodiment, as shown in FIG. 4, the above-described gypsum slurry dewatering system 1 includes the above-described liquid level acquisition device 93 and the liquid level height H3 acquired by the liquid level acquisition device 93. and a control device 94A (94) including an opening degree instruction unit 942 configured to instruct the opening degree to the flow control valve 95 in response to the flow rate control valve 95.
[0064]
The control device 94A is an electronic control unit for adjusting the opening degree of the flow control valve 95, and includes a CPU (processor) (not shown), memories such as ROM and RAM, storage devices such as external storage devices, I/O interfaces, It may be configured as a microcomputer including a communication interface and the like. Each functional unit is implemented by the CPU operating (for example, calculating data) according to the instructions of the program loaded in the main storage device of the memory, for example. The control device 94A is configured to be able to transmit and receive signals to and from the flow rate control valve 95 and the liquid level acquisition device 93 . The flow control valve 95 is electrically controlled by a signal sent from the control device 94A, and according to the signal, the valve body of the flow control valve 95 is driven to open and close the flow path inside the flow control valve 95. , the opening degree of the flow control valve 95 can be adjusted to a desired opening degree other than fully closed and fully opened. As such a flow control valve 95, for example, a control valve can be used. In the illustrated embodiment, the flow rate control valve 95 is provided downstream of the water supply pipe 91 (on the absorbent storage tank 17 side) of the water supply pump 92 .
[0065]
In the illustrated embodiment, the opening instruction unit 942 instructs the flow control valve 95 to be fully closed when the liquid level H3 sent from the liquid level acquisition device 93 is less than the lower limit threshold value LH. direct to. Further, when the liquid level height H3 sent from the liquid level acquisition device 93 is equal to or higher than the lower limit threshold value LH, the flow control valve 95 is closed. tell it to open. Further, when the liquid level height H3 sent from the liquid level height acquisition device 93 is equal to or lower than the upper limit threshold value UH and equal to or higher than the lower limit threshold value LH, the opening degree instruction unit 942 causes the flow rate control valve 95 to change its opening degree. The first opening degree is instructed. When the liquid level height H3 sent from the liquid level height acquisition device 93 exceeds the upper limit threshold value UH, the flow rate control valve 95 is set to the first degree of opening that is larger than the first degree of opening. 2 (for example, fully open). In some other embodiments, the opening instruction unit 942 instructs the flow rate control valve 95 continuously or stepwise as the liquid level H3 sent from the liquid level acquisition device 93 increases. It may be configured to increase the flow rate of the liquid passing through the flow control valve 95 by increasing the degree of opening.
[0066]
In addition, in some other embodiments, the flow control valve 95 described above has two positions, fully closed and fully open, but may be configured so that it cannot be adjusted to any opening other than fully closed and fully open. The degree-of-opening instruction section 942 instructs the flow rate control valve 95 to be either fully open or fully closed as the degree of opening. In this case, the opening instruction unit 942 can increase the flow rate of the liquid passing through the flow control valve 95 by increasing the proportion of the period during which the flow control valve 95 is fully opened within the certain period. As such a flow control valve 95, for example, an electromagnetic valve may be used.
[0067]
As described above, not only the filter cloth cleaning liquid but also the filtrate overflowing from the filtrate storage tank 6 is sent to the filter cloth cleaning liquid storage tank 8, so that the level of the liquid stored in the filter cloth cleaning liquid storage tank 8 is There is a risk that the liquid will overflow from the filter cloth cleaning liquid storage tank 8 due to a sudden and large increase in height. According to the above configuration, the water supply line 9 includes the water supply pipe 91 , a water pump 92 provided in the water supply pipe 91 , and a flow control valve 95 provided in the water supply pipe 91 . The flow rate control valve 95 is configured such that its opening degree is controlled according to the level of the liquid stored in the filter cloth washing liquid storage tank 8 . In this case, the opening of the flow rate control valve 95 is controlled so that the level of the liquid stored in the filter cloth cleaning liquid storage tank 8 does not become excessively high, so that the above It is possible to suppress the overflow of the liquid.
[0068]
The present disclosure is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.
[0069]
The contents described in the several embodiments described above can be understood, for example, as follows.
[0070]
1) A gypsum slurry dewatering system (1) according to at least one embodiment of the present disclosure,
A gypsum slurry dewatering system (1) for dewatering gypsum slurry discharged from a flue gas desulfurization device (20),
a conveying device (3) having a conveying belt (32) for conveying the gypsum slurry placed on the filter cloth (31);
a filter cloth cleaning device (5) having an ejection portion (filter cloth cleaning liquid ejection portion 51) capable of ejecting a filter cloth cleaning liquid onto the filter cloth (31);
a filtrate storage tank (6) configured to store the filtrate separated from the gypsum slurry by the filter cloth (31);
A filtrate discharge line (7) configured to send the filtrate stored in the filtrate storage tank (6) to a wastewater treatment facility (16) for performing a treatment for discharging the filtrate out of the system. When,
A filter cloth cleaning liquid storage tank (8) different from the filtrate storage tank (6), wherein the filter cloth is ejected from the ejection portion (filter cloth cleaning liquid ejection portion 51) onto the filter cloth (31). and a filter cloth cleaning liquid reservoir (8) configured to store at least the cleaning liquid.
[0071]
The gypsum slurry discharged from the flue gas desulfurization equipment absorbs impurities (for example, suspended matter such as combustion ash and soot removed from the flue gas, pollutants such as dissolved heavy metals, etc.) from the flue gas in the flue gas desulfurization equipment. there is Then, impurities are separated from the gypsum slurry together with the filtrate in a dehydration treatment facility (for example, a conveying device, etc.). In addition, the cake washing liquid used for washing the cake contains impurities such as metal ions such as magnesium (Mg), chlorine (Cl) and sodium (Na). For this reason, the cake washing liquid sent to the filtrate storage tank as the filtrate after washing the filtrate and the cake separated from the gypsum slurry, compared to the filter cloth washing liquid jetted onto the filter cloth, High content of impurities. Filtrate with a high impurity content is used as absorption liquid in flue gas desulfurization equipment.If it is returned to the circulation system, the content of impurities in the absorbent in the flue gas desulfurization unit increases, which is not appropriate. The filtrate having a high content of impurities is preferably discharged out of the system after the wastewater treatment in a wastewater treatment facility.
[0072]
According to the above configuration 1), the filtrate separated from the gypsum slurry and the cake washing liquid used for washing the cake can be stored in the filtrate storage tank (6), and the filter cloth ejected onto the filter cloth The washing liquid can be stored in the filter cloth washing liquid reservoir (8). Then, the filtrate stored in the filtrate storage tank can be sent to the wastewater treatment facility (16) through the filtrate discharge line (7), and discharged outside the system after the wastewater treatment in the wastewater treatment facility. In this way, the filtrate with a high impurity content rate and the filter cloth washing liquid with a low impurity content rate are stored separately, and the wastewater sent to the wastewater treatment facility is treated as the impurity content rate in the filtrate storage tank. By limiting the filtrate to a filtrate with a high D, the amount of waste water sent from the gypsum slurry dehydration treatment equipment to the waste water treatment equipment can be reduced by the amount of the filter cloth washing liquid. In addition, by reducing the amount of wastewater sent to the wastewater treatment equipment, it is possible to prevent the wastewater treatment equipment from becoming large and the equipment costs from increasing.
[0073]
2) In some embodiments, the gypsum slurry dewatering system (1) according to 1) above,
In the filtrate storage tank (6), of the filtrate stored in the filtrate storage tank (6), the filtrate exceeding a predetermined height overflows the filter cloth washing liquid storage tank (8). configured as
[0074]
According to the above configuration 2), the filtrate storage tank (6) is configured such that, of the filtrate stored in the filtrate storage tank, the filtrate exceeding a predetermined height overflows the filter cloth washing liquid storage tank (8). configured to flow. Therefore, the filtrate other than the predetermined amount of filtrate that needs to be sent to the wastewater treatment facility (16) is sent to the filter cloth washing liquid storage tank (8) without using complicated equipment such as a pump and level control. It is possible to suppress the complication and increase in cost of equipment.
Further, for example, even when the filtrate storage tank (8) is supplied with an amount of filtrate that exceeds the amount that can be treated by the wastewater treatment equipment (16), If only the amount of filtrate that can be processed is sent, the remaining amount of filtrate that exceeds the amount that can be processed naturally overflows into the filter cloth washing liquid storage tank (8), and the filter cloth washing liquid is stored. Since the waste water is stored in the tank (8), the waste water treatment facility (16) does not need to be large in size, and the increase in cost of the waste water treatment facility (16) can be suppressed.
[0075]
3) In some embodiments, the gypsum slurry dewatering system (1) according to 2) above,
The filtrate discharge line (7) is
a drainage pipe (71) connected to the filtrate storage tank (6) and the drainage treatment facility (16);
a drainage pump (72) provided in the drainage pipe (71);
Provided on the downstream side of the drainage pump (72) in the drainage pipe (71), and configured to be able to adjust the flow rate of the filtrate sent from the filtrate storage tank (6) to the drainage treatment facility (16) and a flow control valve (73).
[0076]
According to the configuration of 3) above, the filtrate discharge line includes a drainage pipe connected to the filtrate storage tank and the wastewater treatment facility, a drainage pump provided in the drainage pipe, and a drainage pump downstream of the drainage pipe. Since the provided flow rate control valve is included, the flow rate of the filtrate sent from the filtrate storage tank to the waste water treatment facility via the waste water pipe can be adjusted. Therefore, the filtrate discharge line can send an amount of filtrate to the wastewater treatment facility according to the treatment performance of the wastewater treatment facility.
[0077]
4) In some embodiments, the gypsum slurry dewatering system (1) according to 3) above,
an absorbent storage tank (17) configured to store an absorbent that is brought into gas-liquid contact with the exhaust gas in the flue gas desulfurization apparatus (20);
and a water feed line (9) configured to send the liquid stored in the filter cloth washing liquid storage tank (8) to the absorbent storage tank (17).
[0078]
Since the amount of impurities adhering to the filter cloth after gypsum discharge is small, the filter cloth cleaning liquid has a low impurity content even if it absorbs the impurities adhering to the filter cloth. Filtrate with a high impurity content may overflow from the filtrate storage tank into the filter cloth cleaning liquid storage tank. The content of impurities is lower than that of the filtrate stored in the filtrate storage tank. According to the configuration of 4) above, the liquid stored in the filter cloth cleaning liquid storage tank having a low impurity content is sent to the absorbent storage tank 17 via the water supply line, so that the liquid is transferred to the flue gas desulfurization apparatus. It can be returned to the circulation system of the absorbing liquid in and reused as the absorbing liquid.
[0079]
5) In some embodiments, the gypsum slurry dewatering system (1) according to 4) above,
The above water supply line (9) is
a water supply pipe (91) connected to the filter cloth cleaning liquid storage tank (8) and the absorbent liquid storage tank (17);
including a water pump (92) provided in the water pipe (91),
The water pump (92) is configured such that the rotation speed is controlled according to the liquid level height of the liquid stored in the filter cloth washing liquid storage tank (8).
[0080]
Since not only the filter cloth washing liquid but also the filtrate overflowing from the filtrate storage tank (6) is sent to the filter cloth washing liquid storage tank, the level of the liquid stored in the filter cloth washing liquid storage tank rises rapidly. There is a risk that the liquid will overflow from the filter cloth washing liquid storage tank due to a large rise. According to the above configuration 5), the water supply line includes a water supply pipe connected to the filter cloth washing liquid storage tank and the absorbent storage tank, and a water supply pump provided in the water supply pipe. The water pump is configured such that its rotation speed is controlled according to the liquid level height of the liquid stored in the filter cloth washing liquid storage tank. In this case, the rotation speed of the water pump is controlled so that the level of the liquid stored in the filter cloth washing liquid storage tank does not become excessively high, thereby preventing the liquid from overflowing from the filter cloth washing liquid storage tank. can be suppressed.
[0081]
6) In some embodiments, the gypsum slurry dewatering system (1) according to 4) above,
The above water supply line (9) is
a water supply pipe (91) connected to the filter cloth cleaning liquid storage tank (8) and the absorbent liquid storage tank (17);
a water pump (92) provided in the water pipe (91);
a flow rate control valve (95) provided in the water supply pipe (91) and capable of adjusting the flow rate of the liquid sent from the filter cloth cleaning liquid storage tank (8) to the absorbent storage tank (17); including
The flow rate control valve (95) is configured such that the degree of opening is controlled according to the liquid level height of the liquid stored in the filter cloth washing liquid storage tank (8).
[0082]
As described above, not only the filter cloth washing liquid but also the filtrate overflowing from the filtrate storage tank (6) is sent to the filter cloth washing liquid storage tank, so that the level of the liquid stored in the filter cloth washing liquid storage tank There is a risk that the liquid will overflow from the filter cloth cleaning liquid storage tank due to a sudden and large increase in height. According to the configuration of 6) above, the water supply line includes the water supply pipe, a water supply pump provided in the water supply pipe, and a flow control valve provided in the water supply pipe. The flow rate control valve is configured such that the degree of opening thereof is controlled according to the level of the liquid stored in the filter cloth cleaning liquid storage tank. In this case, the degree of opening of the flow rate control valve is controlled so that the level of the liquid stored in the filter cloth cleaning liquid storage tank does not become excessively high, so that the liquid overflows from the filter cloth cleaning liquid storage tank. can be suppressed.
Code explanation
[0083]
1 Gypsum slurry dehydration system
3 Conveyor
31 filter cloth
311 supported part
312 Upper surface
32 Conveyor belt
321 Upper surface
322 support part
33, 33A, 33B drum
34 motor
35 Guide roller
36 Dehydration department
37 Dehydrator
371 dehydration room
372 Vacuum pump
373 decompression piping
374 Vacuum tank
375 Liquid discharge piping
4 Supply device
41 supply department
42 Supply piping
43 Gypsum discharge part
44 cake washing device
45 Cake washing liquid ejection part
46 Cake washing liquid supply pipe
47 pump
5 Filter cloth washing device
51 Filter cloth washing liquid ejection part
52 Filter cloth washing liquid supply pipe
53 Pump
54 Steam ejection device
55 Steam ejection part
56 Steam piping
58 Filter cloth washing liquid receiver
59 Filter cloth washing liquid discharge pipe
6 Filtrate storage tank
61 Internal space
62 Inner side
63 Bottom
64 Weir
7 Filtrate discharge line
71 Drainage piping
72 Drainage pump
73 Flow control valve
8 Filter cloth washing liquid storage tank
81 Internal space
82 Inner side
83 bottom
9 Water supply line
91 Water supply piping
92 Water pump
93 Liquid level acquisition device
94, 94A Control device
941 rpm indicator
942 Opening indicator
95 Flow control valve
10 Exhaust gas cleaning system
11 Combustion equipment
12 Absorption liquid supply line
121 Absorption liquid supply pipe
122 supply pump
13 Absorption liquid circulation line
131 Absorption liquid circulation pipe
132 Circulation pump
133 First branch part
14 Absorption liquid withdrawal line
141 Piping
142 Regulating valve
143 Second branch part
15 Absorption liquid return line
151 Absorption liquid return piping
16 Exhaust gas treatment equipment
161 1st coagulation sedimentation tank
162 Internal space
163 Second coagulation sedimentation tank
164 Internal space
165 1st flocculant addition line
166 Second flocculant addition line
167 Weir
168 partitions
17 Absorption liquid storage tank
171 Internal space
20 Flue gas desulfurization equipment
20A absorption tower
21 Internal space
21A Gas-liquid contact part
21B liquid pool
22 Absorption tower body
221 Absorption liquid extraction port
222 Nozzle through hole
223 absorption liquid supply port
224 absorption liquid return port
23 Exhaust gas inlet
24 Exhaust gas outlet
25 Mist eliminator
26 Atomization device
261 Spray pipe
262 spray nozzle
263 Spray port
27 Oxidizing gas supply device
271 nozzle
272 pump
273 opening
LH Lower limit threshold
UH upper limit threshold

The scope of the claims

[Claim 1]
A gypsum slurry dewatering system for dewatering gypsum slurry discharged from flue gas desulfurization equipment,
a conveying device having a conveying belt that conveys the gypsum slurry placed on the filter cloth;
a filter cloth cleaning device having a jetting part capable of jetting a filter cloth cleaning liquid onto the filter cloth;
a filtrate storage tank configured to store the filtrate separated from the gypsum slurry by the filter cloth;
a filtrate discharge line configured to send the filtrate stored in the filtrate storage tank to a wastewater treatment facility that performs a process for discharging the filtrate out of the system;
a filter cloth cleaning liquid storage tank different from the filtrate storage tank, the filter cloth cleaning liquid storage tank configured to store at least the filter cloth cleaning liquid ejected from the ejection portion onto the filter cloth;
gypsum slurry dewatering system.
[Claim 2]
The filtrate storage tank is configured such that, of the filtrate stored in the filtrate storage tank, the filtrate exceeding a predetermined height overflows the filter cloth washing liquid storage tank.
The gypsum slurry dewatering system according to claim 1.
[Claim 3]
The filtrate discharge line is
a drainage pipe connected to the filtrate storage tank and the drainage treatment facility;
A drainage pump provided in the drainage pipe,
　The drainage pump in the drainage pipeand a flow rate adjustment valve provided downstream of the filtrate storage tank and configured to adjust the flow rate of the filtrate sent from the filtrate storage tank to the wastewater treatment facility.
The gypsum slurry dewatering system according to claim 2.
[Claim 4]
an absorbent storage tank configured to store an absorbent that is brought into gas-liquid contact with the exhaust gas in the flue gas desulfurization apparatus;
and a water supply line configured to send the liquid stored in the filter cloth cleaning liquid storage tank to the absorbent storage tank.
The gypsum slurry dewatering system according to claim 3.
[Claim 5]
　The water supply line is
a water supply pipe connected to the filter cloth cleaning liquid storage tank and the absorbent storage tank;
including a water pump provided in the water pipe,
The water pump is configured such that the rotation speed is controlled according to the liquid level height of the liquid stored in the filter cloth washing liquid storage tank.
The gypsum slurry dewatering system according to claim 4.
[Claim 6]
　The water supply line is
a water supply pipe connected to the filter cloth cleaning liquid storage tank and the absorbent storage tank;
a water pump installed in the water pipe,
a flow rate control valve provided in the water supply pipe and configured to be able to adjust the flow rate of the liquid sent from the filter cloth cleaning liquid storage tank to the absorbent storage tank,
The flow rate control valve is configured so that the degree of opening is controlled according to the liquid level height of the liquid stored in the filter cloth washing liquid storage tank.
The gypsum slurry dewatering system according to claim 4.