Chemical concentrated water recovery system for desulfurization process water

Abstract

The utility model discloses a chemical concentrated water recovery system for desulfurization process water, which comprises a 1 # water drainage cellar, a 2 # water drainage cellar, a 4 # water drainage cellar and a 5 # water drainage cellar, the 1 # water drainage cellar is respectively connected with a chemical workshop, the 2 # water drainage cellar and the 4 # water drainage cellar through a pipeline I, a pipeline II and a pipeline III, the 2 # water drainage cellar is connected with a desulfurization system through a pipeline IV, and the 5 # water drainage cellar is connected with the desulfurization system through a pipeline IV. The desulfurization system is connected with the circulating water system through a pipeline V; the concentrated water tank is additionally arranged between the 1 # water drainage cellar and the 2 # water drainage cellar, the concentrated water pump is arranged at the outlet of the concentrated water tank, and the pneumatic flashboard is arranged in the 4 # water drainage cellar, so that water can be continuously supplied for desulfurization for 24 hours; meanwhile, remote transmission to a remote upper computer DCS is achieved through the DCS, and remote operation and monitoring of starting, stopping, remote, local and running states of the pump, frequency control and feedback of the frequency converter, current display, the liquid level of the concentrated water recovery pit and the like are achieved through the DCS.

Description

Technical Field

[0001] The utility model relates to the technical field of concentrated water recovery, in particular to a chemical concentrated water recovery system for desulfurization process water. Background Art

[0002] Water resources are basic natural resources and strategic economic resources. They are also an important foundation for sustainable social and economic development and maintaining ecological balance and environmental harmony. The power industry is a basic industry and an important energy industry. It is a major industrial water user and has great water-saving potential. Under the premise of ensuring the safety and economic operation of the unit, we should actively carry out the comprehensive utilization of water resources to achieve the goals of water saving and emission reduction, reducing power generation costs, and protecting the ecological environment. In thermal power plants, industrial water mainly includes two parts: one part is circulating cooling water, which is mainly used for equipment cooling; the other part is boiler feed water, which is mainly used to supplement the normal losses in the steam-water cycle of the thermal system. Due to the strict requirements on the quality of boiler feed water, industrial water needs to be treated to remove suspended matter, colloids and ionic impurities to meet the requirements. In the process of industrial water treatment, the chemical water treatment system will produce self-use water. When the chemical water treatment process is complicated, the amount of self-use water is often large. Therefore, it is very necessary and beneficial to recycle the self-use water of the chemical water treatment system. Utility Model Content

[0003] In order to solve the above technical problems, the technical solution provided by the utility model is: a chemical concentrated water recovery system for desulfurization process water, including 1# drainage cellar, 2# drainage cellar, 4# drainage cellar and 5# drainage cellar, the 1# drainage cellar is connected to the chemical workshop, 2# drainage cellar and 4# drainage cellar through pipeline 1, pipeline 2 and pipeline 3 respectively, the 2# drainage cellar is connected to the desulfurization system through pipeline 4, and the desulfurization system is connected to the circulating water system through pipeline 5; the 4# drainage cellar is connected to the 5# drainage cellar through pipeline 6, and the 5# drainage cellar is connected to the industrial wastewater system through pipeline 7; the pipeline 2 between the 1# drainage cellar and the 2# drainage cellar is connected to the concentrated water tank through pipeline 8, the concentrated water tank is connected to the pipeline 4 through the concentrated water pump and pipeline 9, and valves are respectively provided on the pipeline 8, pipeline 4 and pipeline 5.

[0004] Compared with the prior art, the utility model has the following advantages: the utility model adds a concentrated water tank between the 1# drainage pit and the 2# drainage pit, installs a concentrated water pump at the outlet of the concentrated water tank, and installs a pneumatic gate in the 4# drainage pit, which can continuously supply water for desulfurization 24 hours a day; at the same time, the DCS control system is remotely transmitted to the remote host computer DCS system, and the DCS realizes remote operation and monitoring of the start, stop, remote, local, and operating states of the pump, the frequency control and feedback of the frequency converter, the current display, the liquid level of the concentrated water recovery pit, etc.

[0005] The utility model mainly classifies and recycles the chemical concentrated water according to the principle of "tiered use and clean and dirty water diversion", thereby increasing the crystallization speed of desulfurized gypsum and reducing equipment investment and operation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 The utility model is a connection schematic diagram of a chemical concentrated water recovery system for desulfurization process water.

[0007] Figure 2 The utility model is a circuit diagram of a chemical concentrated water recovery system for desulfurization process water. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0009] In the description of the embodiments of the present utility model, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0010] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0011] In the description of the embodiments of the present invention, "multiple" means at least 2.

[0012] In the description of the embodiments of the present utility model, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0013] Example:

[0014] The main technical problem solved by this embodiment is that the desulfurization uses factory circulating water, a large amount of municipal reclaimed water is added to the circulating water, and the reclaimed water system is treated with chemicals to treat the tower pool. The coagulant and a large amount of organic matter added to the circulating water can hinder the growth of desulfurized gypsum grains, causing unfavorable growth of gypsum crystals. Therefore, the use of circulating water as desulfurization process water will have a certain impact on the desulfurization process; chemical concentrated water has the characteristics of low turbidity and high salt content. Using chemical concentrated water for desulfurization process water is a more ideal choice.

[0015] 1. Analysis of water used by chemical water treatment system:

[0016] 1. Due to the different water sources for chemical water treatment, the process flow adopted by the chemical water treatment system is different; generally, surface water (as the water source for chemical water treatment, the process flow is: four-chamber activated carbon filter → three sets of ultrafiltration → three sets of primary reverse osmosis → three sets of secondary reverse osmosis + EDI. The four-chamber activated carbon filter and the yield system are called the pretreatment system, which mainly removes suspended matter, colloids, residual chlorine, microorganisms and other macromolecular substances and impurities in the water. The reverse osmosis and EDI system are called the desalination system, which mainly removes ions in the water.

[0017] 2. When the water production system operates normally, the pretreatment system and the desalination system will produce a certain amount of drainage, which is collectively called chemical concentrated water. The salt content of the concentrated water discharged by the pretreatment system remains basically unchanged, and the turbidity is relatively high. The turbidity of the concentrated water discharged by the desalination system remains basically unchanged, and the salt content increases significantly.

[0018] 2. When the concentrated water is reused as desulfurization process water, the following factors should be considered:

[0019] 1. Influence of concentrated water quality on corrosion of desulfurization system

[0020] When the desulfurization process water system is made of carbon steel, it is generally believed that corrosion will occur when the Cl- concentration is above 150 mg / L. If the Cl- increases to 800 mg / L, the corrosion will be aggravated. The plant circulating water is used for desulfurization process water for a long time, and the Cl- concentration of the tower pool circulating water is about 700 mg / L. Therefore, chemical concentrated water will not have a serious impact on the corrosion of the desulfurization system.

[0021] 2. Effect of chloride ion content in desulfurization process water on gypsum quality

[0022] The chloride ion content in the absorber of wet desulfurization process design is not more than 20000mg / L. The chloride ion in the desulfurization absorber mainly comes from dry coal and process water. The C- in the process water has little effect on the chloride ion content in the absorber. The chloride ion concentration in the absorber can be maintained by appropriately increasing the discharge of desulfurization wastewater. The quality of gypsum is mainly affected by the slurry concentration, pH and oxidation crystallization conditions in the desulfurization absorber.

[0023] 3. Impact on salt accumulation and scaling in the demister of the desulfurization absorption tower

[0024] Due to the characteristics of chemical concentrated water, the use of concentrated water to flush the desulfurization absorber demister will increase the tendency of salt accumulation and scaling. However, since the desulfurization absorber demister is usually made of PP non-metallic materials and the nozzle itself is in the environment of gypsum slurry medium, the effect of concentrated water on the salt accumulation and scaling of the desulfurization absorber demister will be diluted. When using concentrated water as desulfurization process water, it is necessary to do a good job of desulfurization system supervision, inspection and use effect evaluation during the unit maintenance period.

[0025] Therefore, it is determined that chemical concentrated water can be used for desulfurization for a long time, and the concentrated water recovery system is improved. The specific plan is as follows:

[0026] Combined with Figure 1 A chemical concentrated water recovery system for desulfurization process water comprises a 1# drainage cellar 1, a 2# drainage cellar 2, a 4# drainage cellar 3 and a 5# drainage cellar 4, wherein the 1# drainage cellar 1 is connected to a chemical workshop 8, a 2# drainage cellar 2 and a 4# drainage cellar 3 through a pipeline 1 5, a pipeline 2 6 and a pipeline 3 7 respectively, the 2# drainage cellar 2 is connected to a desulfurization system 10 through a pipeline 4 9, and the desulfurization system 10 is connected to a circulating water system 12 through a pipeline 5 11; the 4# drainage cellar 3 is connected to the 5# drainage cellar 4 through a pipeline 6 13, and the 5# drainage cellar 4 is connected to an industrial wastewater system 15 through a pipeline 7 14; a concentrated water tank 17 is connected to the pipeline 2 6 between the 1# drainage cellar 1 and the 2# drainage cellar 2 through a pipeline 8 16, and the concentrated water tank 17 is connected to the pipeline 4 9 through a concentrated water pump 18 and a pipeline 9 19, and valves 20 are respectively provided on the pipeline 8 16, the pipeline 4 9 and the pipeline 5 11; and a pneumatic gate is provided in the 4# drainage cellar 3.

[0027] Combined with Figure 2 The circulating water system is equipped with a DCS control system connected to the concentrated water pump, a stop indication circuit, an operation indication circuit, a manual start-stop circuit, an automatic control circuit, an automatic liquid level control circuit and a variable frequency pneumatic circuit. The DCS control system is connected to the remote upper DCS system for data transmission.

[0028] The stop indication circuit and the operation indication circuit respectively include an intermediate relay KA1, an indicator light 1, an intermediate relay KA2, and an indicator light 2 which form a circuit with an external power supply.

[0029] The manual start-stop circuit includes a transfer switch SA1 and an intermediate relay KA3 connected to a DCS control system. The DCS control system, the transfer switch SA1, the intermediate relay KA3 and an external power supply form a loop, and the other end of the transfer switch SA1 is connected to an automatic control circuit.

[0030] The automatic control circuit includes a conversion switch SA2 connected to the conversion switch SA1, and a liquid level meter YW1, and the liquid level meter YW1 is connected to the DCS control system; the other end of the conversion switch SA2 is connected to the DCS control system through a button switch SB1 and a push-button switch SB2; the button switch SB1 and the push-button switch SB2 are connected to the DCS control system through an intermediate relay KA4.

[0031] The automatic liquid level control circuit includes a liquid level meter YW1 and a liquid level meter YW2. Pin 15 and pin 16 of the liquid level meter YW1 and the liquid level meter YW2 are connected to the DCS control system to output a high liquid level signal. Pin 17 and pin 16 of the liquid level meter YW1 and the liquid level meter YW2 are connected to the DCS control system to output a low liquid level signal. Pin 19 and pin 10 of the liquid level meter YW1 and the liquid level meter YW2 are connected to the DCS control system to output an analog output signal. Pin 02 and pin 21 of the liquid level meter YW1 and the liquid level meter YW2 are connected to a two-wire liquid level transmitter.

[0032] The variable frequency pneumatic circuit includes a frequency converter. Pins AI1 and AI2 of the frequency converter are connected to the DCS control system for analog input. Pins A01 and A02 of the frequency converter are connected to the DCS control system for analog output. Pins DI1 and COM of the frequency converter are connected through an intermediate relay KA5.

[0033] Transformation effect: During the operation of the chemical water system, the final desalted water volume accounts for about 55% of the total incoming water volume, and the concentrated water discharge accounts for about 45% of the total incoming water volume. Among them, the four-chamber activated carbon filter is backwashed regularly in the morning shift every day, with a backwashing discharge volume of about 180 tons. A single set of ultrafiltration is backwashed every 40 minutes, with a discharge volume of about 12 tons each time. A single set of first-level reverse osmosis discharges about 17 tons per hour, and the second-level reverse osmosis discharges water back to the ultrafiltration water tank. The EDI single set discharges about 4 tons per hour; the daily water production in summer is about 1,000 tons, and the concentrated water is discharged about 800 tons; the daily water production in winter is about 2,000 tons, and the concentrated water is discharged about 1,600 tons; the desulfurization process water consumption is about 1,300 tons during the winter heating period, and the water consumption in summer or during single-machine operation is about 750 tons. The chemical concentrated water just meets the desulfurization process water consumption, which greatly reduces the water intake, provides a guarantee for water use indicators, and increases economic benefits.

[0034] The above description of the utility model and its implementation methods is not restrictive. The drawings show only one implementation method of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention of the utility model, they should all fall within the protection scope of the utility model.

Claims

1. A chemical concentrated water recovery system for desulfurization process water, It is characterized in that It includes 1# drainage cellar, 2# drainage cellar, 4# drainage cellar and 5# drainage cellar. The 1# drainage cellar is connected to the chemical workshop, 2# drainage cellar and 4# drainage cellar through pipeline 1, pipeline 2 and pipeline 3 respectively. The 2# drainage cellar is connected to the desulfurization system through pipeline 4, and the desulfurization system is connected to the circulating water system through pipeline 5; the 4# drainage cellar is connected to the 5# drainage cellar through pipeline 6, and the 5# drainage cellar is connected to the industrial wastewater system through pipeline 7; the pipeline 2 between the 1# drainage cellar and the 2# drainage cellar is connected to the concentrated water tank through pipeline 8, and the concentrated water tank is connected to pipeline 4 through a concentrated water pump and pipeline 9, and valves are respectively provided on pipeline 8, pipeline 4 and pipeline 5.

2. A chemical concentrated water recovery system for desulfurization process water according to claim 1, It is characterized in that A pneumatic gate is arranged in the 4# drainage pit.

3. A chemical concentrated water recovery system for desulfurization process water according to claim 1, It is characterized in that The circulating water system is provided with a DCS control system connected to a concentrated water pump, a stop indication circuit, an operation indication circuit, a manual start-stop circuit, an automatic control circuit, an automatic liquid level control circuit and a variable frequency pneumatic circuit. The DCS control system is connected to a remote host computer DCS system for data transmission.

4. A chemical concentrated water recovery system for desulfurization process water according to claim 3, It is characterized in that The stop indication circuit and the operation indication circuit respectively include an intermediate relay KA1, an indicator light 1, an intermediate relay KA2, and an indicator light 2 which form a loop with an external power supply.

5. A chemical concentrated water recovery system for desulfurization process water according to claim 3, It is characterized in that The manual start-stop circuit includes a conversion switch SA1 and an intermediate relay KA3 connected to a DCS control system. The DCS control system, the conversion switch SA1, the intermediate relay KA3 and an external power supply form a loop, and the other end of the conversion switch SA1 is connected to an automatic control circuit.

6. A chemical concentrated water recovery system for desulfurization process water according to claim 3, It is characterized in that The automatic control circuit includes a conversion switch SA2 connected to the conversion switch SA1, and a liquid level meter YW1, wherein the liquid level meter YW1 is connected to a DCS control system; the other end of the conversion switch SA2 is connected to a DCS control system via a button switch SB1 and a button-type switch SB2; the button switch SB1 and the button-type switch SB2 are connected to a DCS control system via an intermediate relay KA4.

7. A chemical concentrated water recovery system for desulfurization process water according to claim 3, It is characterized in that The automatic liquid level control circuit includes a liquid level meter YW1 and a liquid level meter YW2. Pins 15 and 16 of the liquid level meter YW1 and YW2 are connected to a DCS control system to output a high liquid level signal. Pins 17 and 16 of the liquid level meter YW1 and YW2 are connected to a DCS control system to output a low liquid level signal. Pins 19 and 10 of the liquid level meter YW1 and YW2 are connected to a DCS control system to output an analog output signal. Pins 02 and 21 of the liquid level meter YW1 and YW2 are connected to a two-wire liquid level transmitter.

8. A chemical concentrated water recovery system for desulfurization process water according to claim 3, It is characterized in that The variable frequency pneumatic circuit includes a frequency converter, wherein pins AI1 and AI2 of the frequency converter are connected to a DCS control system for analog quantity input, pins A01 and A02 of the frequency converter are connected to a DCS control system for analog quantity output, and pins DI1 and COM of the frequency converter are connected via an intermediate relay KA5.

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