An integrated desulfurization wastewater concentrate salt extraction equipment

Abstract

The invention discloses a novel integrated desulfurization wastewater concentrate salt extraction equipment, comprising a wastewater tank, a cyclone, a vacuum disc dehydrator, and a steam-water separator. The wastewater tank is connected to a feed pump, and the feed pump pumps wastewater in the wastewater tank into the cyclone. The concentrated solution after being concentrated by the cyclone enters the vacuum disc dehydrator. The vacuum disc dehydrator is connected to the steam-water separator and the vacuum pump. Under the action of the vacuum pump, a vacuum is formed inside the vacuum disc dehydrator, and the crystallized salt with a large specific gravity is adsorbed on the disc of the disc dehydrator. The crystallized salt on the disc is discharged from the disc dehydrator through the backblowing of the air compression tank. The novel integrated desulfurization wastewater concentrate salt extraction equipment separates the concentration section and the salt extraction section of the desulfurization wastewater, expands the nozzle, and allows the desulfurization wastewater to complete concentration only in the flue, avoiding scaling of calcium, magnesium and other substances in the water at the nozzle. The separation of suspended matter and crystallized salt is carried out outside the flue using the equipment described in the invention.

Description

Technical Field

[0001] The invention belongs to the technical field of desulfurization wastewater treatment, and in particular relates to an integrated desulfurization wastewater concentrated liquid salt extraction device. Background Art

[0002] The desulfurization wastewater produced by the wet flue gas desulfurization process in modern industry has a pH value of 4-6 and contains a large amount of suspended matter and soluble salts, such as gypsum particles, Na2SO4, NaCl, etc. Nowadays, there are two main methods for zero emission technology of desulfurization wastewater. The first method is the full membrane method, which is pretreatment + membrane concentration + MVR. It uses ultrafiltration, reverse osmosis, and high-pressure reverse osmosis to achieve the concentration of desulfurization wastewater, and uses MVR to extract salt from the concentrated liquid, but MVR has high energy consumption and high hardness requirements; the second method is the flue spray crystallization method, which is to spray the desulfurization wastewater directly into the flue containing high-temperature flue gas, directly evaporate the water, and the suspended matter and crystallized salt in the wastewater are deposited to the bottom of the flue and captured and separated by the dust collector. The desulfurization wastewater is simultaneously concentrated and separated in the flue, but a fine mist nozzle is required, and because the desulfurization wastewater contains a large amount of calcium and magnesium, it is very easy to scale at the nozzle, causing blockage.

[0003] In order to solve the above-mentioned existing desulfurization wastewater zero-emission technology full membrane MVR high energy consumption and high hardness requirements, waste of human resources, and increase the cost of wastewater treatment; the flue spray crystallization method requires a fine mist nozzle, and the desulfurization wastewater contains a large amount of calcium and magnesium, which is very easy to scale at the nozzle, causing blockage and other problems, an integrated desulfurization wastewater concentrate salt extraction equipment is provided. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art. The existing desulfurization wastewater zero-discharge technology, the full membrane method MVR, has high energy consumption and high hardness requirements; the flue spray crystallization method requires the use of a fine mist nozzle. Since the desulfurization wastewater contains a large amount of calcium and magnesium, it is very easy to scale at the nozzle, causing blockage. An integrated desulfurization wastewater concentrated liquid salt extraction device is provided. The integrated desulfurization wastewater concentrated liquid salt extraction device can achieve the separation of salt in the concentrate with lower energy consumption, separate the concentration section and the salt extraction section of the desulfurization wastewater, expand the nozzle, and allow the desulfurization wastewater to complete the concentration only in the flue, avoiding the scaling of calcium, magnesium and other substances in the water at the nozzle. The separation of suspended matter and crystallized salt is carried out outside the flue using the equipment described in the present invention.

[0005] In order to achieve the above-mentioned purpose, the present invention provides the following technical scheme: an integrated desulfurization wastewater concentrate salt extraction equipment, comprising a wastewater tank, a cyclone, a vacuum disc dehydrator, and a steam-water separator, characterized in that: the wastewater tank is connected to a feed pump, the feed pump pumps the wastewater in the wastewater tank into the cyclone, the concentrated solution concentrated by the cyclone enters the vacuum disc dehydrator, the vacuum disc dehydrator is connected to the steam-water separator and the vacuum pump, under the action of the vacuum pump, a vacuum is formed inside the vacuum disc dehydrator, and the crystallized salt with a large specific gravity is adsorbed on the disc of the vacuum disc dehydrator, and the crystallized salt on the disc is discharged from the vacuum disc dehydrator through backblowing of an air compression tank.

[0006] Preferably, the wastewater tank is connected to the front-end desulfurization wastewater concentration system to form a circulation treatment system to maintain the solid content of the desulfurization wastewater concentrate in the wastewater tank ≥8%.

[0007] Preferably, the feed pump is a corrosion-resistant centrifugal slurry delivery pump, and the outlet pressure of the corrosion-resistant centrifugal slurry delivery pump is greater than the inlet feed pressure of the cyclone.

[0008] Preferably, the cyclone is a double-shell structure with a metal shell and an inner liner of composite ceramics, and a spiral material channel is provided on the surface of the composite ceramics, the supernatant spirals upward, and the crystallized salt spirals downward.

[0009] Preferably, the vacuum disc dehydrator is provided with a disc, a limit switch, and a lower liquid discharge port. The disc is composed of a disc and a fan-shaped plate. The fan-shaped plate adopts a filter cloth-type hollow polypropylene fan-shaped plate. The filter cloth specification is 500-600 g / ㎡. The limit switch is set at the center of the disc, and the rotation speed of the disc is frequency-controlled.

[0010] Preferably, a back-blowing solenoid valve is provided between the vacuum disc dehydrator and the air compression tank, and the filter cake formed by the crystallized salt on the disc of the vacuum disc dehydrator is unloaded by back-blowing with compressed air. The frequency of back-blowing is jointly controlled by the limit switch of the vacuum disc dehydrator and the back-blowing solenoid valve. The limit switch will detect when the disc of the vacuum disc dehydrator rotates, and when the rotation is detected, the limit switch will continuously send a signal to the back-blowing solenoid valve to control the switch of the back-blowing solenoid valve.

[0011] Preferably, the interior of the steam-water separator is divided into two parts, upper and lower, which are respectively connected to the upper drainage solenoid valve and the lower drainage solenoid valve. The steam-water separator discharges liquid by combining the liquid level and the solenoid valve. The water inlet of the steam-water separator is 500mm lower than the drainage port of the vacuum disc dehydrator.

[0012] Preferably, all equipment is integrated into one frame to form an integrated device, and all parts in contact with desulfurization wastewater are made of corrosion-resistant materials.

[0013] Compared with the prior art, the technical advantages of the present invention are:

[0014] The present invention provides an integrated desulfurization wastewater concentrated liquid salt extraction equipment for the desulfurization wastewater zero-discharge treatment process. Compared with the full membrane method, the salt separation in the concentrated liquid can be achieved with lower energy consumption; compared with the flue spray crystallization method, the concentration section and the salt extraction section of the desulfurization wastewater can be separated, and the nozzle can be enlarged so that the desulfurization wastewater can only be concentrated in the flue, avoiding the scaling of calcium, magnesium and other substances in the water at the nozzle. The separation of suspended matter and crystallized salt is carried out outside the flue using the equipment described in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the process of the present invention,

[0016] Figure 2 It is a structural schematic diagram of the present invention,

[0017] Among them, 1 is a waste water tank, 2 is a feed pump, 3 is a cyclone, 4 is a vacuum disc dehydrator, 5 is a steam-water separator, 6 is a vacuum pump, 7 is an air compression tank, 8 is a hopper, 9 is an upper liquid discharge solenoid valve, 10 is a lower liquid discharge solenoid valve, and 11 is a back-blowing solenoid valve. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention application, for those skilled in the art, some changes and improvements made, all other embodiments obtained are within the scope of protection of the present invention.

[0019] Combination Figure 1 Flowchart and Figure 2 The structural schematic diagram of the present invention provides an integrated desulfurization wastewater concentrate salt extraction equipment, and the technical scheme is as follows: an integrated desulfurization wastewater concentrate salt extraction equipment, including a wastewater tank 1, a feed pump 2, a cyclone 3, a vacuum disc dehydrator 4, a steam-water separator 5, a vacuum pump 6, an air compression tank 7, a hopper 8, an upper discharge solenoid valve 9, a lower discharge solenoid valve 10, and a back-blowing solenoid valve 11.

[0020] An integrated desulfurization wastewater concentrate salt extraction device comprises a wastewater tank 1, a cyclone 3, a vacuum disc dehydrator 4, and a steam-water separator 5. The wastewater tank 1 is connected to a feed pump 2. The feed pump pumps the wastewater in the wastewater tank into the cyclone 3. The concentrated solution concentrated by the cyclone 3 enters the vacuum disc dehydrator 4. The vacuum disc dehydrator 4 is connected to the steam-water separator 5 and the vacuum pump 6. Under the action of the vacuum pump 6, a vacuum is formed inside the vacuum disc dehydrator 4, and crystallized salt with a large specific gravity is adsorbed on the disc of the vacuum disc dehydrator 4. The crystallized salt on the disc is discharged from the vacuum disc dehydrator 4 through backblowing of an air compression tank 8.

[0021] The structure and its arrangement relationship are described in detail below in conjunction with the accompanying drawings: An integrated desulfurization wastewater concentrate salt extraction equipment is provided with a wastewater tank 1 for storing desulfurization wastewater. The wastewater tank 1 is connected to the desulfurization wastewater concentration system at the front end to form a circulation treatment system to maintain the solid content of the desulfurization wastewater concentrate in the wastewater tank 1 at ≥8%. In addition, the wastewater tank 1 is connected to the feed pump 2, and the feed pump 2 is a corrosion-resistant centrifugal slurry delivery pump, which can ensure that after the equipment works normally for a period of time, the feed pump 2 will not be corroded due to long-term contact with the desulfurization wastewater, affecting the normal and continuous operation of the equipment. In addition, the feed pump 2, the corrosion-resistant centrifugal slurry delivery pump, has a high head, so that the outlet pressure of the corrosion-resistant centrifugal slurry delivery pump is greater than the inlet feed pressure of the cyclone 3 by 0.1Mpa, ensuring that the desulfurization wastewater can enter the cyclone 3 at a certain pressure from the wastewater tank 1 through the feed pump 2.

[0022] The feed pump 2 is connected to the cyclone 3, and the upper water outlet of the cyclone 3 is connected to the wastewater tank 1, and the lower water outlet of the cyclone 3 is connected to the vacuum disc dehydrator 4. The desulfurized wastewater from the wastewater tank 1 through the feed pump 2 is further concentrated through the cyclone 3, so that the salt content of the desulfurized wastewater containing crystallized salt is increased to 20-30%. In addition, the cyclone 3 is a double-shell structure of a metal shell lined with a composite ceramic, and there is a spiral material channel on the surface of the composite ceramic. When the desulfurized wastewater concentrate is concentrated by the cyclone 3, the supernatant spirals upward and flows back to the wastewater tank 1 from the upper outlet of the cyclone 3, and the crystallized salt spirals downward and enters the vacuum disc dehydrator 4 from the lower outlet of the cyclone 3 to extract the salt, thereby achieving the purpose of material concentration.

[0023] The vacuum disc dehydrator 4 is connected to the hopper 8, and a back-blowing solenoid valve 11 is arranged between the vacuum disc dehydrator 4 and the air compression tank 7. The vacuum disc dehydrator 4 is made of corrosion-resistant material to ensure that after the equipment works normally for a period of time, the vacuum disc dehydrator 4 will not be corroded due to the long-term contact between the vacuum disc dehydrator 4 and the desulfurization wastewater, which will affect the continuous operation of the equipment. The vacuum disc dehydrator 4 is provided with a disc, a limit switch, and a lower liquid discharge port. The disc is composed of a disc and a fan-shaped plate. The limit switch is arranged at the center of the disc, and the speed of the disc is controlled by frequency conversion. In other words, the speed of the vacuum disc dehydrator 4 is controlled by frequency conversion, and the thickness of the crystallized salt separated on the disc is related to the speed of the disc of the vacuum disc dehydrator 4, so as to ensure that the thickness of the filter cake formed by the crystallized salt is controlled to be more than 1 cm. If the thickness of the filter cake is not reached, it is easy to destroy the vacuum state inside the vacuum disc dehydrator 4. At this time, the speed of the disc can be controlled by frequency modulation to make the filter cake reach a certain thickness. The fan-shaped plate of the vacuum disc dehydrator 4 is made of hollow polypropylene, and the filter cloth specification is 500-600g / ㎡. The filter cake formed by the crystallized salt on the disc of the vacuum disc dehydrator 4 is discharged by back-blowing with compressed air, and the frequency of back-blowing is controlled by a limit switch and a normally closed back-blowing solenoid valve 11. When the disc of the vacuum disc dehydrator 4 rotates, the limit switch will detect, and when the rotation is detected, it will continuously send a signal to the back-blowing solenoid valve 11 to control the switch of the back-blowing solenoid valve 11. Under the action of the vacuum pump 6, a vacuum is formed inside the vacuum disc dehydrator 4, and the crystallized salt with a large specific gravity is adsorbed on the disc of the vacuum disc dehydrator 4. The crystallized salt on the disc enters the hopper 8 through the back-blowing of the air compression tank 7 and is discharged for transportation.

[0024] The vacuum disc dehydrator 4 is connected to the steam-water separator 5 arranged on one side, and the upper and lower parts of the steam-water separator 5 are respectively connected to the upper drainage solenoid valve 9 and the lower drainage solenoid valve 10, and the upper part of the steam-water separator 5 is connected to the vacuum pump 6. The upper water inlet of the steam-water separator 5 is 500mm lower than the lower drainage port of the vacuum disc dehydrator 4, which can facilitate the vacuum disc dehydrator 4 to smoothly enter the filtrate formed after the concentrated solution extracts salt from the vacuum disc dehydrator 4 into the steam-water separator 5. The steam-water separator 5 adopts a liquid level and a solenoid valve combination to discharge liquid. The interior of the steam-water separator 5 is divided into an upper and lower part. After the action of the vacuum pump 6, the filtrate first enters the upper part of the steam-water separator 5. After the liquid level of the filtrate reaches the set value, the upper drainage solenoid valve 9 is opened, and the filtrate enters the lower part from the upper part of the steam-water separator 5, and then the lower drainage solenoid valve 10 is opened to discharge the filtrate. The pipe connected to the vacuum pump 6 on the upper part of the steam-water separator 5 is 1.5-2.0m higher than the interface. The filtrate of the vacuum disc dehydrator 4 enters the steam-water separator 5 through the action of the vacuum pump 6, and flows back to the wastewater tank 1 after steam-water separation.

[0025] The integrated desulfurization wastewater concentrated liquid salt extraction equipment integrates all equipment into a frame to form an integrated equipment. In addition, all parts of the new integrated desulfurization wastewater concentrated liquid salt extraction equipment that are in contact with desulfurization wastewater are made of corrosion-resistant materials to avoid corrosion of the equipment due to long-term contact with desulfurization wastewater and affecting the continued normal use of the equipment. The discharge liquid of the steam-water separator 5 and the upper discharge liquid of the cyclone 3 are returned to the wastewater tank 1, and the filtrate after salt extraction enters the front-end desulfurization wastewater concentration system for concentration, forming a circulating treatment system with the desulfurization wastewater concentration system to maintain the solid content of the desulfurization wastewater concentrate in the wastewater tank 1 ≥8%.

[0026] The present invention provides an integrated desulfurization wastewater concentrated liquid salt extraction equipment for the desulfurization wastewater zero emission treatment process, which can realize the separation of salt in the concentrated liquid with low energy consumption, and can separate the concentration section and the salt extraction section of the desulfurization wastewater, and expand the nozzle so that the desulfurization wastewater can only be concentrated in the flue to avoid scaling of calcium, magnesium and other substances in the water at the nozzle. The separation of suspended matter and crystallized salt is carried out outside the flue using the equipment of the present invention, thereby realizing zero emission of desulfurization wastewater.

[0027] Combination Figure 1Flow chart, the working process of the present invention is as follows: when the new integrated desulfurization wastewater concentrated liquid salt extraction equipment is used to work normally and continuously, the desulfurization wastewater stored in the wastewater tank 1 is transported to the cyclone 3 at a certain pressure through a corrosion-resistant centrifugal slurry delivery pump. The cyclone 3 further concentrates the desulfurization wastewater, increases the salt content of the desulfurization wastewater to 20-30%, and improves the dehydration effect. Because the cyclone 3 is a double-shell structure of a metal shell lined with a composite ceramic, and there is a spiral material channel on the surface of the composite ceramic, after the desulfurization wastewater passes through the cyclone 3 to achieve material concentration, the supernatant spirals upward and flows back from the upper outlet of the cyclone 3 to the wastewater tank 1 of the new integrated desulfurization wastewater concentrated liquid salt extraction equipment, and the crystallized salt spirals downward and enters the vacuum disc dehydrator 4 from the lower outlet of the cyclone 3 to extract salt. Under the action of the vacuum pump 6, a vacuum state is formed inside the vacuum disc dehydrator 4, and the heavy crystallized salt is adsorbed on the disc of the vacuum disc dehydrator 4. The crystallized salt on the disc is backblown by the air compression tank 7 and enters the hopper 8, and the crystallized salt is discharged and transported. The moisture content of the crystallized salt is 40%-50%. The filter plate of the vacuum disc dehydrator 4 adopts a hollow polypropylene fan-shaped plate, and the filter cloth specification is 500-600g / ㎡. The moisture content of the separated crystallized salt is 40%-50%. The filtrate formed after the concentrated solution of the vacuum disc dehydrator 4 extracts the salt enters the steam-water separator 5 through the action of the vacuum pump 6. The steam-water separator 5 uses a combination of liquid level and solenoid valve to discharge liquid. The interior of the steam-water separator 5 is divided into two parts, upper and lower. After the action of the vacuum pump 6, the filtrate first enters the upper part of the steam-water separator 5. After the liquid level reaches the set value, the upper drainage solenoid valve 9 opens, and the filtrate enters the lower part from the upper part of the steam-water separator 5. Then, the lower drainage solenoid valve 10 is opened to discharge the filtrate. After passing through the steam-water separator 5, the filtrate flows back to the wastewater tank 1. The filtrate after salt extraction enters the desulfurization wastewater concentration system at the front end of this equipment for concentration, and forms a circulating treatment system with the desulfurization wastewater concentration system to maintain the solid content of the desulfurization wastewater concentrate in the wastewater tank 1 ≥8%.

[0028] The above description of the present invention is only a preferred implementation mode of the present invention application in combination with the accompanying drawings, but is not intended to limit the scope of protection of the present invention application. It should be pointed out that for technical personnel in the relevant field, without departing from the overall concept of the present invention, any modifications, equivalent substitutions, improvements, etc. made by technical personnel in this field without creative labor should be included in the scope of protection of the present invention application.

Claims

1. An integrated desulfurization wastewater concentrate salt extraction device, comprising a wastewater tank (1), a cyclone (3), a vacuum disc dehydrator (4), and a steam-water separator (5). Features: The wastewater tank (1) is connected to the feed pump (2), the feed pump (2) pumps the wastewater in the wastewater tank (1) into the cyclone (3), the concentrated solution after being concentrated by the cyclone (3) enters the vacuum disc dehydrator (4), the vacuum disc dehydrator (4) is connected to the steam-water separator (5) and the vacuum pump (6), under the action of the vacuum pump (6), a vacuum is formed inside the vacuum disc dehydrator (4), and the crystallized salt with a large specific gravity is adsorbed on the disc of the vacuum disc dehydrator (4), and the crystallized salt on the disc is discharged from the vacuum disc dehydrator (4) through backblowing of the air compression tank (7); The cyclone (3) is a double-shell structure with a metal shell and a composite ceramic liner. The composite ceramic surface has a spiral material channel, the supernatant spirals upward, and the crystallized salt spirals downward; The vacuum disc dehydrator (4) is provided with a disc, a limit switch, and a lower liquid discharge port. The disc is composed of a disc and a fan-shaped plate. The fan-shaped plate adopts a filter cloth type hollow polypropylene fan-shaped plate. The limit switch is arranged at the center of the disc. The rotation speed of the disc is controlled by frequency conversion. A back-blowing solenoid valve (11) is provided between the vacuum disc dehydrator (4) and the air compression tank (7). The filter cake formed by the crystallized salt on the disc of the vacuum disc dehydrator (4) is discharged by back-blowing with compressed air. The frequency of back-blowing is controlled by the limit switch of the vacuum disc dehydrator (4) and the back-blowing solenoid valve (11). When the disc of the vacuum disc dehydrator (4) rotates, the limit switch detects. When the rotation is detected, the limit switch continuously transmits a signal to the back-blowing solenoid valve (11) to control the switch of the back-blowing solenoid valve (11).

2. The integrated desulfurization wastewater concentrate salt extraction equipment according to claim 1, Features: The wastewater tank (1) is connected to the desulfurization wastewater concentration system at the front end to form a circulation treatment system, so as to maintain the solid content of the desulfurization wastewater concentrate in the wastewater tank (1) to be ≥8%.

3. The integrated desulfurization wastewater concentrate salt extraction equipment according to claim 1, Features: The feed pump (2) is a corrosion-resistant centrifugal slurry delivery pump, and the outlet pressure of the corrosion-resistant centrifugal slurry delivery pump is greater than the inlet feed pressure of the cyclone (3).

4. The integrated desulfurization wastewater concentrate salt extraction equipment according to claim 1, Features: The interior of the steam-water separator (5) is divided into two parts, an upper part and an lower part, which are respectively connected to an upper liquid discharge solenoid valve (9) and a lower liquid discharge solenoid valve (10). The steam-water separator (5) discharges liquid by combining the liquid level with the solenoid valve. The water inlet of the steam-water separator (5) is 500 mm lower than the liquid discharge port of the vacuum disc dehydrator (4).

5. The integrated desulfurization wastewater concentrate salt extraction equipment according to claim 1, Features: All equipment is integrated into one frame to form an integrated device, and all parts in contact with desulfurization wastewater are made of corrosion-resistant materials.

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