1. The utility model provides a coal fired power plant desulfurization gypsum appreciation, zero release of desulfurization waste water comprehensive treatment equipment which characterized by: the system comprises a pulping machine, a desulfurizing tower, a waste heat recovery machine, a gypsum slurry dehydrator, a gypsum cleaning machine (1), a circulating water film concentrator, a water storage tank, a bypass flue spray evaporator, a continuous beta gypsum production line, a vertical beta gypsum calcining furnace (2) and a continuous alpha gypsum production line, wherein the continuous beta gypsum production line comprises the vertical beta gypsum calcining furnace (2); tail gas of the coal-fired power plant is conveyed to the desulfurizing tower through a flue and conveyed to a waste heat recovery machine and a bypass flue spraying evaporator through a bypass flue, and the waste heat recovery machine and the bypass flue spraying evaporator are connected with the desulfurizing tower through a return flue; conveying the calcium carbonate stone powder to a pulping machine through a conveyor, wherein the pulping machine is connected with a desulfurization tower through a stone slurry conveying pipeline; the desulfurizing tower is connected with the gypsum slurry dehydrator through a gypsum slurry pipeline; the gypsum slurry dehydrator is connected with the gypsum cleaning machine (1) through a gypsum conveyor, is connected with the pulping machine through a water return pipeline, and is connected with the circulating water film concentrator through a circulating water pipeline; the gypsum cleaning machine (1) is connected with a water source, the circulating water film concentrator is connected with the water storage tank through a pipeline, the gypsum cleaning machine (1) is also connected with the pulping machine through a water return pipeline, and the circulating water film concentrator is also connected with the bypass flue spray evaporator through a concentrated solution pipeline; the gypsum cleaning machine (1) is connected with a continuous beta gypsum production line and a continuous alpha gypsum production line through a conveyor, and the continuous beta gypsum production line and the continuous alpha gypsum production line are connected with a waste heat recovery machine through oil pipelines; the water storage tank is connected with the pulping machine and the gypsum cleaning machine (1) through a water supply pipeline, and the water storage tank is connected with a water source through a water pipe.

2. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant according to claim 1, which is characterized in that: the gypsum slurry dehydrator and the gypsum cleaning machine (1) are respectively provided with a chloride ion concentration sensor which is electrically connected with the monitoring equipment.

3. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant according to claim 1, which is characterized in that: the gypsum cleaning machine (1) comprises a filter belt (1.1); the lower part of the working section of the filter belt (1.1) is provided with a first vacuum chamber (1.2), a second vacuum chamber (1.3) and a third vacuum chamber (1.4), and the third vacuum chamber (1.4) is provided with a chloride ion concentration sensor (1.10); the upper part of the working section of the filter belt (1.1) is provided with a first cleaning water pipe (1.5), a second cleaning water pipe (1.6) and a third cleaning water pipe (1.7) corresponding to the first vacuum chamber (1.2), the second vacuum chamber (1.3) and the third vacuum chamber (1.4) respectively; the tail part of the working section of the filter belt (1.1) is provided with a material receiving box A (1.8), and the material receiving box A (1.8) is correspondingly provided with a screw conveyor A (1.9).

4. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant as recited in claim 3, which is characterized in that: the first cleaning water pipe (1.5), the second cleaning water pipe (1.6) and the third cleaning water pipe (1.7) are fixedly arranged on the upper part of the filter belt (1.1) in a direction vertical to the movement direction of the filter belt (1.1), the first cleaning water pipe (1.5), the second cleaning water pipe (1.6) and the third cleaning water pipe (1.7) are respectively provided with a plurality of spray heads, and cleaning water is sprayed on the filter belt (1.1) in fine water drops through the spray heads; the distance from the first cleaning water pipe (1.5) to the third cleaning water pipe (1.7) is less than 1/3 of the length of the working section of the filter belt (1.1).

5. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant as recited in claim 3, which is characterized in that: the first cleaning water pipe (1.5), the second cleaning water pipe (1.6) and the third cleaning water pipe (1.7) are independently provided with an electric control valve, and the electric control valve is electrically connected with the monitoring equipment.

6. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant according to claim 1, which is characterized in that: the vertical beta gypsum calcining furnace (2) comprises a furnace body (2.1) and a base (2.5), wherein the furnace body (2.1) is fixedly arranged on the upper part of the base (2.5), and the base (2.5) is provided with a maintenance manhole; the furnace body (2.1) is of a double-layer structure and comprises an inner furnace wall and an outer furnace wall; a plurality of groups of heating oil pipes (2.2) are fixedly wound between the inner furnace wall and the outer furnace wall, and a heat insulating material (2.3) is filled between the inner furnace wall and the outer furnace wall; a rotating shaft (2.4) is vertically and rotatably arranged in the furnace body (2.1), and a spiral feeding plate (2.4.1) is welded on the rotating shaft (2.4); the lower part of the rotating shaft (2.4) is in movable transmission connection with a motor reduction box component (2.6); a discharge hole is formed in the lower portion of the furnace body (2.1), a material receiving box B (2.7) is fixedly arranged corresponding to the discharge hole, and a spiral conveyor B (2.9) is correspondingly arranged on the material receiving box B (2.7); the upper part of the furnace body (2.1) is provided with a feeding hole.

7. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant as recited in claim 6, which is characterized in that: in the section along the axis of the rotating shaft (2.4), a downward included angle is arranged between the spiral feeding plate (2.4.1) and the axis, and the included angle ranges from 85 degrees to 75 degrees.

8. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant as recited in claim 6, which is characterized in that: the furnace body (2.1) is provided with a plurality of temperature sensors (2.8), and the temperature sensors (2.8) are arranged in contact with the inner furnace wall and are electrically connected with the monitoring equipment.

9. The value-added desulfurization gypsum and desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant as recited in claim 6, which is characterized in that: the material receiving box B (2.7) arranged at the lower part of the furnace body (2.1) is connected with the outer wall of the furnace body in a sealing way.

10. The treatment process of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment based on the coal-fired power plant of claim 1 is characterized in that: comprises a desulfurization gypsum treatment process and a desulfurization wastewater treatment process;

the desulfurization gypsum treatment process flow comprises the following steps: dehydrating gypsum slurry, cleaning gypsum, producing alpha gypsum and producing beta gypsum; wherein the production of alpha gypsum and the production of beta gypsum are parallel processes and are produced asynchronously; the production of alpha gypsum and the production of beta gypsum are both in a continuous production mode; the concentration of chloride ions is controlled by the gypsum cleaning machine after the gypsum is cleaned;

the desulfurization wastewater treatment process comprises two water circulations, namely a large circulation and a small circulation; the large circulation comprises limestone powder pulping, absorption tower desulfurization, gypsum slurry dehydration, gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small circulation comprises gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small cycle is contained in the large cycle;

in the desulfurization wastewater treatment process, the balance of large circulating water and small circulating water is adjusted by a water storage tank;

in the desulfurization wastewater treatment process, the control of the chloride ion concentration of the large circulating water is realized by a concentration filtration process; the concentration and filtration process is in an intermittent operation mode, and the operation is started and stopped by monitoring equipment according to monitoring data output by a chloride ion concentration sensor arranged on the gypsum slurry dehydrator;

in the desulfurization wastewater treatment process, the concentration of chloride ions in the small circulating water is controlled by adjusting the water yields of a first cleaning water pipe (1.5), a second cleaning water pipe (1.6) and a third cleaning water pipe (1.7); the water yield of the first cleaning water pipe (1.5), the second cleaning water pipe (1.6) and the third cleaning water pipe (1.7) is controlled by monitoring equipment according to monitoring data output by a chloride ion concentration sensor (1.10) arranged on the gypsum cleaning machine (1).

Background

In recent years, the domestic environmental protection is continuously increased, the environmental protection requirement of the thermal power industry is gradually strict, but from the practical implementation effect of the zero emission standard, the problems in the thermal power industry are not fundamentally solved, and the fundamental reason is as follows: the zero emission treatment cost of the solid waste and the liquid waste of the coal-fired power plant is really realized, so that the cost is too high and enterprises are not willing; in order to reduce the desulfurization wastewater treatment cost, the existing method of thermal power enterprises is as follows: the desulfurization wastewater is continuously recycled until the content of chloride ions in the desulfurization wastewater is too high, severe corrosion is generated on equipment and the service life of the equipment is influenced, the desulfurization wastewater is concentrated, and the concentrated desulfurization wastewater is sprayed in coal cinder and coal ash to be taken away by measures of reducing the temperature of the coal cinder and reducing fly ash flying dust, so that zero emission is realized; however, in the actual treatment process of the coal cinder and the fly ash, harmful substances contained in the coal cinder and the fly ash can permeate into surrounding soil to cause secondary pollution to the environment, and zero emission is not really realized, so that the desulfurization wastewater treatment process of the existing single technical route of the coal-fired power plant is difficult to consider environmental protection targets and cost at the same time, and becomes a 'solid disease' of the current coal-fired power plant.

In addition, the existing method for treating the waste liquid in the thermal power enterprise can cause the content of chloride ions in the other byproduct namely desulfurized gypsum generated in the desulfurization process of the thermal power enterprise to be too high, so that the method cannot be used in large quantity and can be only sold and treated in a solid waste mode at low cost; however, the actual gypsum is an energy-saving and environment-friendly mineral resource, has wide application and higher value in many fields, and the desulfurized gypsum produced by the existing thermal power enterprises is treated as solid waste, so that the waste of the resource is extremely large.

Disclosure of Invention

In order to overcome the defects in the background art, the invention discloses a coal-fired power plant desulfurized gypsum value-added and desulfurized wastewater zero-discharge comprehensive treatment device and a process, which comprises a pulping machine, a desulfurizing tower, a waste heat recovery machine, a gypsum slurry dehydrator, a gypsum cleaning machine, a circulating water film concentrator, a water storage tank, a bypass flue spray evaporator, a continuous beta gypsum production line and a continuous alpha gypsum production line; on the basis of the original desulfurization equipment and process of the coal-fired power plant, equipment for detecting and controlling the content of chloride ions in circulating water is added, and the desulfurization equipment and process are improved and optimized by combining a waste water bypass flue evaporation system, so that the original high-chloride desulfurization gypsum is converted into low-chloride desulfurization gypsum; meanwhile, a continuous alpha gypsum and beta gypsum processing production line is added, and the low-chlorine desulfurized gypsum is processed into a high-value energy-saving environment-friendly building material product; high economic benefit is obtained by selling high-value gypsum products, and then the high economic benefit is used for reverse treatment of the desulfurization waste water, so that zero emission of desulfurization waste of the coal-fired power plant is realized, and meanwhile, the coal-fired power plant obtains high economic benefit; therefore, the problem that the existing desulfurization wastewater treatment of the coal-fired power plant is difficult to consider the environmental protection target and the cost 'stubborn disease' is solved fundamentally, and the coal-fired thermal power generation industry realizes the virtuous circle and sustainable development of environmental protection and economic benefit.

In order to realize the purpose, the invention adopts the following technical scheme: a coal-fired power plant desulfurized gypsum value-added and desulfurized wastewater zero-discharge comprehensive treatment device and a process thereof comprise a pulping machine, a desulfurizing tower, a waste heat recovery machine, a gypsum slurry dehydrator, a gypsum cleaning machine, a circulating water film concentrator, a water storage tank, a bypass flue spray evaporator, a continuous beta gypsum production line and a continuous alpha gypsum production line, wherein the continuous beta gypsum production line comprises a vertical beta gypsum calcining furnace; tail gas of the coal-fired power plant is conveyed to the desulfurizing tower through a flue and conveyed to a waste heat recovery machine and a bypass flue spraying evaporator through a bypass flue, and the waste heat recovery machine and the bypass flue spraying evaporator are connected with the desulfurizing tower through a return flue; conveying the calcium carbonate stone powder to a pulping machine through a conveyor, wherein the pulping machine is connected with a desulfurization tower through a stone slurry conveying pipeline; the desulfurizing tower is connected with the gypsum slurry dehydrator through a gypsum slurry pipeline; the gypsum slurry dehydrator is connected with the gypsum cleaning machine through a gypsum conveyor, connected with the pulping machine through a water return pipeline and connected with the circulating water film concentrator through a circulating water pipeline; a straight-through water pipeline is also connected between the gypsum slurry dehydrator and the pulping machine; the gypsum cleaning machine is connected with a water source; the circulating water film concentrator is connected with the water storage tank through a pipeline, the gypsum cleaning machine is also connected with the pulping machine through a water return pipeline, and the circulating water film concentrator is also connected with the bypass flue spray evaporator through a concentrated solution pipeline; the gypsum cleaning machine is connected with the continuous beta gypsum production line and the continuous alpha gypsum production line through the conveyor, and the continuous beta gypsum production line and the continuous alpha gypsum production line are connected with the waste heat recovery machine through oil pipelines; the water storage tank is connected with the pulping machine and the gypsum cleaning machine through a water supply pipeline, and is connected with a water source through a water pipe; the invention relates to a value-added desulfurization waste water zero-discharge comprehensive treatment device and a process for desulfurization gypsum of a coal-fired power plant, which is characterized in that a gypsum cleaning machine, a bypass flue spray evaporator, a continuous beta gypsum production line and a continuous alpha gypsum production line are added on the basis of original solid waste and liquid waste treatment devices of a thermal power enterprise, the original solid waste and treatment process is changed, high-chlorine gypsum is converted into low-chlorine gypsum, the low-chlorine gypsum is processed and converted into high-value alpha gypsum, beta gypsum and environment-friendly gypsum building material products or further processed into gypsum mortar, so that a byproduct 'desulfurization gypsum' generated in the tail gas desulfurization treatment process of the thermal power enterprise is greatly increased in value, high economic benefits are obtained by selling the high-value alpha gypsum, beta gypsum and environment-friendly gypsum building material products, and high economic benefits are used for feeding back the desulfurization waste water treatment, and simultaneously, extremely high economic benefits can be obtained, therefore, thermal power enterprises really wish to treat the desulfurization wastewater, the zero emission of the thermal power enterprises is really realized, and the virtuous circle and sustainable development of environmental protection and economic benefits of the coal-fired thermal power generation industry are realized.

Furthermore, a chloride ion concentration sensor is respectively arranged on the gypsum slurry dehydrator and the gypsum cleaning machine, and is electrically connected with the monitoring equipment; the key control parameter of the desulfurization gypsum value-added and desulfurization wastewater zero-discharge comprehensive treatment equipment and the process of the coal-fired power plant is the chloride ion content of produced gypsum, wherein a chloride ion concentration sensor arranged on a gypsum slurry dehydrator is used for monitoring the chloride ion content of water in a large circulation in a desulfurization wastewater treatment process, and a chloride ion concentration sensor arranged on a gypsum cleaning machine is used for monitoring the chloride ion content of water in a small circulation in the desulfurization wastewater treatment process; in the actual operation of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment and the process of the coal-fired power plant, the circulating water film concentrator and the bypass flue spray evaporator work intermittently, and the reason is that the content of chloride ions is different due to different coal-fired varieties and production places of the coal-fired power plant, and the circulating water film concentrator and the bypass flue spray evaporator are started to operate only when the content of the chloride ions in water in the large circulation reaches or exceeds a set standard, so that the operation time of the circulating water film concentrator and the bypass flue spray evaporator can be reduced, and the effects of reducing energy consumption and prolonging the service life of the circulating water film concentrator and the bypass flue spray evaporator are achieved; the start and stop of the circulating water film concentrator are determined by the chloride ion concentration collected by a chloride ion concentration sensor arranged on the gypsum slurry dehydrator, and when the circulating water film concentrator stops working, the circulating water output by the gypsum slurry dehydrator is directly conveyed back to the pulping machine by a pipeline; monitoring the content of chloride ions in the desulfurized gypsum is realized by the content of chloride ions in small circulating water in a desulfurization wastewater treatment process, the content of chloride ions in tertiary cleaning water collected by a third vacuum chamber of a gypsum cleaning machine is actually monitored, and the content of chloride ions in finally produced alpha gypsum and beta gypsum can be calculated by the monitored content of chloride ions in the tertiary cleaning water and the water content of gypsum treated by the gypsum cleaning machine; when the gypsum cleaning machine works, the actual water spraying amount of the first cleaning water pipe, the second cleaning water pipe and the third cleaning water pipe is controlled according to the chloride ion concentration collected by the chloride ion concentration sensor, so that the chloride ion content in the cleaned gypsum is ensured, and the aim of optimizing the whole working energy consumption of the gypsum cleaning machine can be fulfilled.

Further, the gypsum cleaning machine comprises a filter belt; the lower part of the filter belt working section is provided with a first vacuum chamber, a second vacuum chamber and a third vacuum chamber, and the third vacuum chamber is provided with a chloride ion concentration sensor; the upper part of the filter belt working section is provided with a first cleaning water pipe, a second cleaning water pipe and a third cleaning water pipe corresponding to the first vacuum chamber, the second vacuum chamber and the third vacuum chamber respectively; a material receiving box A is arranged at the tail part of the working section of the filter belt, and a spiral conveyor A is correspondingly arranged on the material receiving box A; the gypsum is washed for three times, the chloride ion concentration of circulating water after each washing is different, wherein the chloride ion concentration of primary washing water is highest, the chloride ion concentration of secondary washing water is second, the chloride ion concentration of tertiary washing water is lowest, three vacuum chambers are arranged to separate the circulating water after the gypsum is washed for three times, the primary washing water is directly conveyed to a pulping machine for recycling, and the secondary washing water and the tertiary washing water are conveyed to a water storage tank to be mixed and then are recycled to the pulping machine.

Furthermore, the first cleaning water pipe, the second cleaning water pipe and the third cleaning water pipe are fixedly arranged at the upper part of the filter belt in a direction vertical to the movement direction of the filter belt, the first cleaning water pipe, the second cleaning water pipe and the third cleaning water pipe are respectively provided with a plurality of spray heads, the cleaning water is sprayed on the filter belt in fine water drops through the spray heads, the plurality of spray heads are arranged to uniformly spray the cleaning water in the width direction of the filter belt, and the fine water drops sprayed by the spray heads can prevent the gypsum from being unevenly distributed on the filter belt due to the fact that the single water flow is too large; the distance from the first cleaning water pipe to the third cleaning water pipe is smaller than 1/3 of the length of the working section of the filter belt, the design aims to prevent the problem that the water content of the gypsum after cleaning is too high due to insufficient vacuum dehydration length of the filter belt after the gypsum is cleaned, and the water content of the gypsum after cleaning is actually controlled to be below 10%.

Furthermore, first washing water pipe, second washing water pipe, third washing water pipe are provided with electric control valve independently, electric control valve and supervisory equipment electric connection, and electric control valve is used for controlling the actual water spray volume of first washing water pipe, second washing water pipe, third washing water pipe to reach the purpose of the whole work energy consumption of control gypsum cleaning machine.

Further, the vertical beta gypsum calcining furnace comprises a furnace body and a base, wherein the furnace body is fixedly arranged on the upper part of the base, and the base is provided with a maintenance manhole; the furnace body is of a double-layer structure and comprises an inner furnace wall and an outer furnace wall; a plurality of groups of heating oil pipes are fixedly wound between the inner furnace wall and the outer furnace wall, and heat insulating materials are filled between the inner furnace wall and the outer furnace wall; a rotating shaft is vertically and rotatably arranged in the furnace body, a spiral feeding plate is welded on the rotating shaft, and a motor reduction box component is movably connected to the lower part of the rotating shaft in a transmission way; a discharge port is formed in the lower part of the furnace body, a material receiving box B is fixedly arranged corresponding to the discharge port, and a spiral conveyor B is correspondingly arranged on the material receiving box B; the upper part of the furnace body is provided with a feed inlet; the hot oil pipes arranged in groups can independently control the heating of the continuous beta gypsum production line, so that the uniformity of the temperature in the whole furnace body is ensured; the heat insulation material filled between the inner furnace wall and the outer furnace wall reduces the surface temperature of the furnace body, prevents the furnace body from radiating excessive heat outwards and reduces the heat loss; the gypsum is continuously and slowly conveyed from the furnace top to the furnace bottom through the rotation of the spiral feeding plate, so that the production continuity and the gypsum calcination time are ensured, meanwhile, the gypsum is heated more uniformly, the phenomenon of 'half-grown' is avoided, the produced beta gypsum is not required to be aged, the beta gypsum is directly used for processing indoor plastering mortar or ground self-leveling mortar products, and the whole production period is shortened; the vertical beta gypsum calcining furnace has the advantages of small volume, small occupied production area, low equipment cost, accurate temperature control, low energy consumption, short production period and high product quality, so compared with the existing rotary kiln beta gypsum production, the vertical beta gypsum calcining furnace has the competitive advantages of high cost and product quality.

Furthermore, in the section along the axis of the rotating shaft, a downward included angle is arranged between the spiral feeding plate and the axis, and the included angle ranges from 85 degrees to 75 degrees; when the gypsum is conveyed downwards on the spiral feeding plate, relative sliding needs to be generated between the gypsum and the spiral feeding plate, and the power of the relative sliding is derived from the friction between the gypsum and the inner wall of the gypsum calcining furnace; spiral delivery sheet and axis set up the contained angle, can make the gypsum on the spiral delivery sheet to gypsum calciner inner wall direction gathering in the downward transportation process, increased the friction between gypsum and the gypsum calciner inner wall, friction between gypsum and the gypsum calciner inner wall still can make the gypsum in the downward transportation process in addition, takes place horizontally "stirring" effect automatically, makes the gypsum be heated more evenly.

Furthermore, a plurality of temperature sensors are arranged on the furnace body, and the temperature sensors are arranged in contact with the inner furnace wall and are electrically connected with the monitoring equipment; the temperature sensors are used for monitoring the temperature of each part in the gypsum calcining furnace, so that the temperature of each part in the gypsum calcining furnace is more uniform; in addition, the temperature of the gypsum calcining furnace is controlled by PID, and the temperature in the furnace body can be accurately controlled at 180 ℃.

Further, a material receiving box B arranged at the lower part of the furnace body is connected with the outer wall of the furnace body in a sealing way; the lower part of the furnace body is hermetically connected with the outer wall of the furnace body, so that cold air is blocked from entering the furnace body from the lower part of the furnace body, air convection in the furnace body is eliminated, hot air in the furnace body is prevented from escaping from a charging opening at the top of the furnace, and the heat energy loss of the gypsum calcining furnace is greatly reduced.

The treatment process of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment and the process of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant is characterized in that: comprises a desulfurization gypsum treatment process and a desulfurization wastewater treatment process;

the desulfurization gypsum treatment process flow comprises the following steps: dehydrating gypsum slurry, cleaning gypsum, producing alpha gypsum and producing beta gypsum; wherein the production of alpha gypsum and the production of beta gypsum are parallel processes and are produced asynchronously; the production of alpha gypsum and the production of beta gypsum are both in a continuous production mode; the purposes of alpha gypsum production, beta gypsum parallel and asynchronous production are set, and the reliability and continuity of the desulfurized gypsum treatment process are ensured while the desulfurized gypsum is converted into high-value alpha gypsum; compared with beta gypsum, the alpha gypsum has the market selling price of 1200-1500 yuan/ton and the beta gypsum has the market selling price of 300-400 yuan/ton, so that in the process for treating the desulfurized gypsum, the alpha gypsum is preferentially produced, but the alpha gypsum production line is relatively complex and needs to be periodically shut down for overhaul and maintenance, the production of a coal-fired power plant is continuous, the output of the desulfurized gypsum is continuous, the treatment of the desulfurized gypsum is also continuous, and when the alpha gypsum production line is shut down for overhaul and maintenance, the continuous beta gypsum production line is used for producing the beta gypsum, so that the continuity of the treatment of the desulfurized gypsum is ensured; the main equipment vertical beta gypsum calcining furnace in the continuous beta gypsum production line is brand-new beta gypsum production equipment with low cost, so that the continuous beta gypsum production line is arranged in parallel in the desulfurized gypsum treatment process, and the benefit of the continuous beta gypsum calcining furnace is still superior to the benefit of the increase of the overall engineering construction cost; the beta gypsum produced by the continuous beta gypsum production line can be further processed into environment-friendly gypsum building material products such as indoor plastering mortar, self-leveling mortar and the like so as to improve the product sales income;

the desulfurization wastewater treatment process comprises two water circulations, namely a large circulation and a small circulation; the large circulation comprises limestone powder pulping, absorption tower desulfurization, gypsum slurry dehydration, gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small circulation comprises gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small cycle is contained in the large cycle;

in the desulfurization wastewater treatment process, the balance of large circulating water and small circulating water is adjusted by a water storage tank;

in the desulfurization wastewater treatment process, water loss links are absorption tower desulfurization and concentration filtration, part of water is evaporated and discharged into the atmosphere along with coal-fired gas during absorption tower desulfurization, the concentrated and filtered high-concentration desulfurization wastewater is treated by a bypass flue spray evaporator, and the water is converted into steam and discharged along with tail gas to generate water loss; circulating water is supplemented and directly injected into the water storage tank, and newly supplemented water can dilute and reduce the concentration of chloride ions in the water storage tank and reduce the content of chloride ions in the final gypsum product; the filtered water generated after the wastewater is concentrated and filtered also has extremely low chloride ion content, so that the filtered water is circularly injected into the water storage tank and can also be diluted to reduce the concentration of the chloride ions in the water storage tank;

in the desulfurization wastewater treatment process, the control of the chloride ion concentration of the large circulating water is realized by a concentration filtration process; the concentration and filtration process is in an intermittent operation mode, and the operation is started and stopped by monitoring equipment according to monitoring data output by a chloride ion concentration sensor arranged on the gypsum slurry dehydrator;

in the desulfurization wastewater treatment process, the concentration control of chloride ions in the small circulating water is controlled by adjusting the water yields of the first cleaning water pipe, the second cleaning water pipe and the third cleaning water pipe; the water yield of the first cleaning water pipe, the second cleaning water pipe and the third cleaning water pipe is controlled by monitoring equipment according to monitoring data output by a chloride ion concentration sensor arranged on the gypsum cleaning machine.

Due to the adoption of the technical scheme, the invention has the following beneficial effects: the invention discloses a coal-fired power plant desulfurized gypsum value-added and desulfurized wastewater zero-discharge comprehensive treatment device and a process, which comprises a pulping machine, a desulfurizing tower, a waste heat recovery machine, a gypsum slurry dehydrator, a gypsum cleaning machine, a circulating water film concentrator, a water storage tank, a bypass flue spray evaporator, a continuous beta gypsum production line and a continuous alpha gypsum production line, wherein the pulping machine is connected with the desulfurizing tower through a pipeline; on the basis of the original desulfurization equipment and process of the coal-fired power plant, equipment for detecting and controlling the content of chloride ions in circulating water is added, and the desulfurization equipment and process are improved and optimized by combining a waste water bypass flue evaporation system, so that the original high-chloride desulfurization gypsum is converted into low-chloride desulfurization gypsum; meanwhile, a continuous alpha gypsum and beta gypsum processing production line is added, and the low-chlorine desulfurized gypsum is processed into a high-value energy-saving environment-friendly building material product; high economic benefit is obtained by selling high-value gypsum products, and then the high economic benefit is used for reverse treatment of the desulfurization waste water, so that zero emission of desulfurization waste of the coal-fired power plant is realized, and meanwhile, the coal-fired power plant obtains high economic benefit; therefore, the problem that the existing desulfurization wastewater treatment of the coal-fired power plant is difficult to consider the environmental protection target and the cost 'stubborn disease' is solved fundamentally, and the coal-fired thermal power generation industry realizes the virtuous circle and sustainable development of environmental protection and economic benefit.

Drawings

FIG. 1 is a schematic diagram of the value-added desulfurization gypsum and zero-discharge desulfurization wastewater comprehensive treatment process flow of a coal-fired power plant;

FIG. 2 is a schematic view of a gypsum cleaning machine;

FIG. 3 is a schematic structural view of a vertical beta gypsum calcining furnace;

FIG. 4 is a schematic view of desulfurization waste water circulation.

In the figure: 1. a gypsum cleaning machine; 1.1, a filter belt; 1.2, a first vacuum chamber; 1.3, a second vacuum chamber; 1.4, a third vacuum chamber; 1.5, a first cleaning water pipe; 1.6, a second cleaning water pipe; 1.7, a third cleaning water pipe; 1.7, a material receiving box A; 1.9, a screw conveyer A; 1.10, a chloride ion concentration sensor; 2. a vertical beta gypsum calciner; 2.1, a furnace body; 2.2, heating an oil pipe; 2.3, heat insulating materials; 2.4, a rotating shaft; 2.4.1, a spiral feeding plate; 2.5, a base; 2.6, a motor reduction box assembly; 2.7, a material receiving box B; 2.8, a temperature sensor; 2.9, a screw conveyer B; 2.10, gypsum powder.

Detailed Description

The present invention will be explained in detail by the following examples, which are disclosed for the purpose of protecting all technical improvements within the scope of the present invention.

A coal-fired power plant desulfurized gypsum value-added and desulfurized wastewater zero-discharge comprehensive treatment device and a process thereof comprise a pulping machine, a desulfurizing tower, a waste heat recovery machine, a gypsum slurry dehydrator, a gypsum cleaning machine 1, a circulating water film concentrator, a water storage tank, a bypass flue spray evaporator, a continuous beta gypsum production line and a continuous alpha gypsum production line, wherein the continuous beta gypsum production line comprises a vertical beta gypsum calcining furnace 2; tail gas of the coal-fired power plant is conveyed to the desulfurizing tower through a flue and conveyed to a waste heat recovery machine and a bypass flue spraying evaporator through a bypass flue, and the waste heat recovery machine and the bypass flue spraying evaporator are connected with the desulfurizing tower through a return flue; conveying the calcium carbonate stone powder to a pulping machine through a conveyor, wherein the pulping machine is connected with a desulfurization tower through a stone slurry conveying pipeline; the desulfurizing tower is connected with the gypsum slurry dehydrator through a gypsum slurry pipeline; the gypsum slurry dehydrator is connected with the gypsum cleaning machine 1 through a gypsum conveyor, is connected with the pulping machine through a water return pipeline, and is connected with the circulating water film concentrator through a circulating water pipeline; a straight-through water pipeline is also connected between the gypsum slurry dehydrator and the pulping machine; the gypsum cleaning machine 1 is connected with a water source; the circulating water film concentrator is connected with the water storage tank through a pipeline, the gypsum cleaning machine 1 is also connected with the pulping machine through a water return pipeline, and the circulating water film concentrator is also connected with the bypass flue spraying evaporator through a concentrated solution pipeline; the gypsum cleaning machine 1 is connected with a continuous beta gypsum production line and a continuous alpha gypsum production line through a conveyor, and the continuous beta gypsum production line and the continuous alpha gypsum production line are connected with a waste heat recovery machine through oil pipelines; the water storage tank is connected with the pulping machine and the gypsum cleaning machine 1 through a water supply pipeline, and is connected with a water source through a water pipe; the gypsum slurry dehydrator and the gypsum cleaning machine 1 are respectively provided with a chloride ion concentration sensor which is electrically connected with the monitoring equipment;

the gypsum cleaning machine 1 comprises a filter belt 1.1; the lower part of the working section of the filter belt 1.1 is provided with a first vacuum chamber 1.2, a second vacuum chamber 1.3 and a third vacuum chamber 1.4, and the third vacuum chamber 1.4 is provided with a chloride ion concentration sensor 1.10; the upper part of the working section of the filter belt 1.1 is provided with a first cleaning water pipe 1.5, a second cleaning water pipe 1.6 and a third cleaning water pipe 1.7 corresponding to the first vacuum chamber 1.2, the second vacuum chamber 1.3 and the third vacuum chamber 1.4 respectively; a material receiving box A1.8 is arranged at the tail part of the working section of the filter belt 1.1, and a spiral conveyor A (1.9) is correspondingly arranged on the material receiving box A1.8;

the first cleaning water pipe 1.5, the second cleaning water pipe 1.6 and the third cleaning water pipe 1.7 are fixedly arranged on the upper part of the filter belt 1.1 in a direction vertical to the movement direction of the filter belt 1.1, the first cleaning water pipe 1.5, the second cleaning water pipe 1.6 and the third cleaning water pipe 1.7 are respectively provided with a plurality of spray heads, and cleaning water is sprayed on the filter belt 1.1 in fine water drops through the spray heads; the distance from the first cleaning water pipe 1.5 to the third cleaning water pipe 1.7 is less than 1/3 of the length of the working section of the filter belt 1.1; the first cleaning water pipe 1.5, the second cleaning water pipe 1.6 and the third cleaning water pipe 1.7 are independently provided with an electric control valve, and the electric control valve is electrically connected with the monitoring equipment;

the vertical beta gypsum calcining furnace 2 comprises a furnace body 2.1 and a base 2.5, wherein the furnace body 2.1 is fixedly arranged on the upper part of the base 2.5, and the base 2.5 is provided with a maintenance manhole; the furnace body 2.1 is a double-layer structure and comprises an inner furnace wall and an outer furnace wall; a plurality of groups of heating oil pipes 2.2 are fixedly wound between the inner furnace wall and the outer furnace wall, and a heat insulating material 2.3 is filled between the inner furnace wall and the outer furnace wall; a rotating shaft 2.4 is vertically and rotatably arranged in the furnace body 2.1, a spiral feeding plate 2.4.1 is welded on the rotating shaft 2.4, and a downward 75-degree included angle is formed between the spiral feeding plate 2.4.1 and the axis in the section along the axis of the rotating shaft 2.4; the lower part of the rotating shaft 2.4 is in movable transmission connection with a motor reduction box component 2.6; a discharge port is arranged at the lower part of the furnace body 2.1, a material receiving box B2.7 is fixedly arranged corresponding to the discharge port, the material receiving box B2.7 is connected with the outer wall of the furnace body in a sealing way, and a spiral conveyor B2.9 is correspondingly arranged on the material receiving box B2.7; the upper part of the furnace body 2.1 is provided with a feed inlet; a plurality of temperature sensors 2.8 are arranged on the furnace body 2.1, and the temperature sensors 2.8 are arranged in contact with the inner furnace wall and are electrically connected with monitoring equipment.

The treatment process of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment and the process of the desulfurization gypsum value-added desulfurization wastewater zero-discharge comprehensive treatment equipment for the coal-fired power plant comprises a desulfurization gypsum treatment process and a desulfurization wastewater treatment process;

the desulfurization gypsum treatment process flow comprises the following steps: dehydrating gypsum slurry, cleaning gypsum, producing alpha gypsum and producing beta gypsum; wherein the production of alpha gypsum and the production of beta gypsum are parallel processes and are produced asynchronously; the production of alpha gypsum and the production of beta gypsum are both in a continuous production mode; the concentration of chloride ions is controlled by the gypsum cleaning machine after the gypsum is cleaned;

the desulfurization wastewater treatment process comprises two water circulations, namely a large circulation and a small circulation; the large circulation comprises limestone powder pulping, absorption tower desulfurization, gypsum slurry dehydration, gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small circulation comprises gypsum cleaning, wastewater concentration and filtration, and filtered water enters a water storage tank for recycling; the small cycle is contained in the large cycle;

in the desulfurization wastewater treatment process, the balance of large circulating water and small circulating water is adjusted by a water storage tank;

in the desulfurization wastewater treatment process, the control of the chloride ion concentration of the large circulating water is realized by a concentration filtration process; the concentration and filtration process is in an intermittent operation mode, and the operation is started and stopped by monitoring equipment according to monitoring data output by a chloride ion concentration sensor arranged on the gypsum slurry dehydrator;

in the desulfurization wastewater treatment process, the concentration of chloride ions in the small circulating water is controlled by adjusting the water yield of a first cleaning water pipe 1.5, a second cleaning water pipe 1.6 and a third cleaning water pipe 1.7; the water yield of the first cleaning water pipe 1.5, the second cleaning water pipe 1.6 and the third cleaning water pipe 1.7 is controlled by monitoring equipment according to monitoring data output by a chloride ion concentration sensor 1.10 arranged on the gypsum cleaning machine 1.

When the coal-fired power plant desulfurization gypsum value-added and desulfurization wastewater zero-discharge comprehensive treatment equipment works, desulfurization gypsum slurry output by a desulfurization tower is conveyed to a gypsum slurry dehydrator through a pipeline for dehydration, high-chlorine gypsum output by the gypsum slurry dehydrator after dehydration is conveyed to a gypsum cleaning machine 1 for chlorine reduction cleaning, and circulating water output by the gypsum slurry dehydrator judges the output direction according to data acquired by a chloride ion concentration sensor; when the concentration of chloride ions is higher than 10000DPPM, the circulating water is conveyed to a circulating water film concentrator for treatment, the treated concentrated high-chlorine water is conveyed to a bypass flue spray evaporator for treatment to produce industrial crude salt, and the circulating water filtered by the circulating water film concentrator is conveyed to a water storage tank for recycling; when the concentration of the chloride ions is less than 10000DPPM, directly conveying the circulating water to a pulping machine for recycling;

the high chlorine gypsum after being cleaned and dehydrated by the gypsum cleaning machine is directly conveyed to a pulping machine for recycling by primary cleaning water, and the secondary cleaning water and the tertiary cleaning water are conveyed to a water storage tank for recycling; a chloride ion concentration sensor arranged in the gypsum cleaning machine monitors the chloride ion concentration of the tertiary cleaning water, and the chloride ion concentration of the tertiary cleaning water is controlled to be always kept below 500DPPM by controlling the water spraying amount of a first cleaning water pipe 1.5, a second cleaning water pipe 1.6 and a third cleaning water pipe 1.7;

conveying the cleaned gypsum to a continuous alpha gypsum production line for treatment to produce high-value alpha gypsum; when the continuous alpha gypsum production line is stopped for maintenance, the cleaned gypsum is conveyed to the continuous beta gypsum production line to produce beta gypsum, and the beta gypsum is further deeply processed into indoor plastering mortar and ground self-leveling mortar; and finally, the alpha gypsum, the indoor plastering mortar and the ground self-leveling mortar are sold to the outside, so that high economic benefit is obtained.

The present invention is not described in detail in the prior art.