Triple-effect evaporation and concentration wastewater treatment equipment and process

Abstract

The invention relates to the technical field of wastewater treatment, and discloses triple-effect evaporation and concentration wastewater treatment equipment and a triple-effect evaporation and concentration wastewater treatment process, the triple-effect evaporation and concentration wastewater treatment equipment comprises a first-effect evaporator, a second-effect evaporator and a third-effect evaporator, and a softening part is mounted on the lower sides of the first-effect evaporator and the second-effect evaporator and is used for reducing the hardness of flowing wastewater and regenerating heat energy; the energy charging part is installed in the softening part and used for compensating secondary steam energy loss through regenerated heat energy, the purification part is installed at the tail end of the softening part, secondary steam energy is compensated, the evaporation efficiency is improved, the softening part and the energy charging part are arranged, and heat generated by the reaction of waste water concentrated liquid and calcium oxide particles is utilized; heat enters the energy charging pipe through the heat release holes and then enters the secondary air inlet pipe to conduct heat compensation on secondary steam, energy attenuation of the secondary steam flowing in the evaporators is reduced, the evaporation efficiency of the second-effect evaporator and the third-effect evaporator is improved, it is ensured that the whole third-effect evaporation system can efficiently treat waste water, and the industrial production requirement is met.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to triple-effect evaporation concentration wastewater treatment equipment and process. Background Art

[0002] In the process of industrial production, a large amount of wastewater will be generated. If these wastewaters are discharged directly, it will not only cause a waste of water resources, but also cause serious pollution to the environment. Therefore, wastewater treatment has become an indispensable part of industrial production. The triple-effect evaporation concentration wastewater treatment equipment and process has been widely used in the field of wastewater treatment due to its advantages of high efficiency and energy saving.

[0003] The three-effect evaporator is mainly composed of three groups of evaporators, condensers, salt separators and auxiliary equipment connected in series. Its working principle is that the high-salt wastewater first enters the first-effect forced circulation crystallization evaporator. In the evaporation heat exchange chamber, the external steam liquefaction generates vaporization latent heat to heat the wastewater. Due to the high pressure in the evaporation heat exchange chamber, the wastewater is heated to superheat at a pressure higher than the normal liquid boiling point. After the heated liquid enters the crystallization evaporation chamber, the pressure drops rapidly, causing part of the wastewater to flash or boil. The steam after the wastewater evaporates enters the second-effect forced circulation evaporator as motive steam to heat the second-effect evaporator. The unevaporated wastewater and salt are temporarily stored in the crystallization evaporation chamber. The first-effect, second-effect and third-effect forced circulation evaporators are connected by a balance pipe. Under the action of negative pressure, the high-salt wastewater flows from the first effect to the second effect and the third effect in turn, and the wastewater is continuously evaporated. The salt concentration in the wastewater becomes higher and higher. When the salt content in the wastewater exceeds the saturation state, the salt in the water will continue to precipitate.

[0004] However, in actual operation, it was found that the secondary steam had energy attenuation when it flowed sequentially in the three-effect evaporator. During the flow of steam, on the one hand, it would exchange heat with the equipment wall of the evaporator, resulting in partial heat loss; on the other hand, as the steam flows sequentially in each effect evaporator, its pressure and temperature would gradually decrease, which would cause the enthalpy of the steam to decrease, that is, the energy carried by the steam would gradually decrease.

[0005] In some traditional three-effect evaporation processes, when the secondary steam generated from the first-effect evaporator enters the second-effect evaporator as a heat source, the evaporation efficiency of the second-effect evaporator is significantly lower than that of the first-effect evaporator due to energy attenuation. When the secondary steam continues to enter the three-effect evaporator, the energy further attenuates, which limits the evaporation capacity of the three-effect evaporator, resulting in low concentration efficiency of the entire three-effect evaporation system, which cannot meet the needs of efficient wastewater treatment.

[0006] At the same time, in order to maintain the normal operation of the triple-effect evaporator, it may be necessary to add more raw steam, which undoubtedly increases energy consumption and operating costs. In addition, the secondary steam energy attenuation may also affect the stability of the entire system, resulting in uneven temperature and pressure distribution in each effect evaporator, thereby affecting the service life of the equipment and the wastewater treatment effect. Therefore, a triple-effect evaporation concentrated wastewater treatment equipment and process is proposed to solve the above-mentioned problems. Summary of the invention

[0007] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a three-effect evaporation concentrated wastewater treatment equipment and process, which solves the problem of energy attenuation when secondary steam flows sequentially in a three-effect evaporator.

[0008] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a three-effect evaporation concentrated wastewater treatment equipment, comprising a first-effect evaporator, a second-effect evaporator and a three-effect evaporator, a softening part installed at the lower side of the first-effect evaporator and the second-effect evaporator, used to reduce the hardness of flowing wastewater and regenerate heat energy, an energy charging part installed in the softening part, used to compensate the secondary steam energy loss with the regenerated heat energy, a purification part installed at the end of the softening part, and removing pollutants in the wastewater by co-precipitation, and a utilization part installed at the upper side of the first-effect evaporator and the second-effect evaporator, and producing hydrogen through oxidation-reduction reaction to complement the secondary steam energy.

[0009] Preferably, the softening part includes a transfer pipe, which is a serpentine structure, one end of the transfer pipe is connected and installed at the bottom of the first-effect evaporator, a transfer pump is installed at the bending part of the transfer pipe, the transfer pipe is connected to the inlet and outlet of the transfer pump, reaction ports are opened on both sides of the straight end of the transfer pipe, the straight end fixed sleeve of the transfer pipe is provided with an insulation tank, the reaction port is located inside the insulation tank, the bottom of the insulation tank is connected and installed with a sedimentation tank, the bottom of the sedimentation tank is connected and installed with a discharge pipe 1, a valve 1 is installed on the discharge pipe 1, the outer wall of the insulation tank is installed with a frame, two tank covers are symmetrically arranged on the top of the insulation tank, and a filter 1 is installed on the side wall of the insulation tank, and the filter 1 is also installed on the straight end of the transfer pipe and connected with the transfer pipe.

[0010] Preferably, the heat preservation tank is of a conical structure, the valve one is a solenoid valve, there are two softening parts, and the transfer pipe in the other softening part is connected and installed at the bottom of the second-effect evaporator.

[0011] Preferably, the charging part includes a partition plate, which is fixedly connected to the middle of the inner wall of the insulation tank on the first-effect evaporator, and the bottom of the partition plate is fixedly connected to the top of the outer wall of the transfer tube on the first-effect evaporator. A reaction hole is opened in the middle of the partition plate, and a charging tube is installed on the inner wall of the reaction hole. A heat release hole is opened on the outer wall of the charging tube. A stopcock is installed on the charging tube, and the stopcock is arranged between the inner walls of the reaction hole. The valve shaft of the stopcock is fixedly connected to an extended valve stem, and a motor is provided at the end of the extended valve stem and fixedly connected to the output shaft of the motor. A liquid level sensor is provided on the charging tube.

[0012] Preferably, the top end of the charging tube is fixedly passed through the top outer side of the partition plate, the motor is mounted on the frame, the extended valve stem movably passes through the outer wall of the insulation tank on the first-effect evaporator, the sensing end of the liquid level sensor passes through the insulation tank on the first-effect evaporator and passes through the inside of the charging tube, the liquid level sensor is mounted on the frame and located below the motor, the two tank covers are respectively mounted on both sides of the partition plate and between the inner wall of the insulation tank, there are two charging parts, and the other charging part is mounted on the insulation tank of the second-effect evaporator and on the top of the outer wall of the transfer tube on the second-effect evaporator.

[0013] Preferably, the purification part includes a purification tank, the purification tank is connected to the straight end of the transfer pipe installed on the first-effect evaporator, the bottom of the purification tank is connected to a discharge pipe 2, the discharge pipe 2 is installed with a valve 2, the valve 2 is a solenoid valve, the outer wall side of the purification tank is connected to a filter 2, the filter 2 is connected to two feed pipes, and an iron plate is fixedly connected between the inner walls of the purification tank.

[0014] Preferably, the utilization part includes two air inlet pipes, the two air inlet pipes are serpentine structures, the bent ends of the two air inlet pipes are connected and installed on the top of the first-effect evaporator, the straight ends of the two air inlet pipes are connected and installed with the top of the charging pipe, the straight ends of the two air inlet pipes are connected and installed with two energy return pipes, valve three is installed on the two energy return pipes, the valve three is an electromagnetic valve, the two energy return pipes are made of transparent material, the bottom ends of the two energy return pipes are connected and installed with a sealing cover, and the sealing cover is installed on the top tank mouth of the purification tank.

[0015] Preferably, there are two purification parts and two utilization parts, and the other purification part and the utilization part are respectively installed on the straight end of the transfer pipe on the second-effect evaporator and the top of the second-effect evaporator, the straight end of the second air inlet pipe on the first-effect evaporator is connected to the second-effect evaporator, the two feed pipes on the first-effect evaporator are connected to the second-effect evaporator, the straight end of the second air inlet pipe on the second-effect evaporator is connected to the three-effect evaporator, and the two feed pipes on the second-effect evaporator are connected to the three-effect evaporator.

[0016] Preferably, the outer wall of the first-effect evaporator is connected and installed with a gas pipe, the top of the three-effect evaporator is connected and installed with a steam pipe, and the bottom of the three-effect evaporator is connected and installed with a concentrated liquid pipe.

[0017] A process for treating wastewater using a triple-effect evaporation concentration device comprises the following steps: Step 1: Pretreatment. The wastewater first enters the pretreatment stage. Suspended matter, grease and other impurities are removed by filtering and adjusting the pH value to ensure that the wastewater is suitable for entering the evaporator. Calcium oxide particles are filled on both sides of the insulation tank separated by the partition plate. Step 2: First-effect evaporation, the pretreated wastewater enters the first-effect evaporator, the raw steam from the boiler enters the heating chamber from the gas pipe and is heated to boiling, generating a large amount of steam, the steam rises into the evaporation chamber, and is separated from the concentrated liquid, the concentrated liquid flows out from the bottom of the evaporation chamber, and enters the insulation tank, purification tank and the second-effect evaporator through the transfer pipe and transfer pump connected to the first-effect evaporator. The secondary steam flows out from the second air inlet pipe of the first-effect evaporator and enters the second-effect evaporator as a heating heat source; Step 3: Heat compensation and wastewater purification. The wastewater concentrate reacts with the calcium oxide particles through the reaction port of the transfer tube to generate calcium hydroxide, and reacts with the magnesium bicarbonate substance in the wastewater to generate calcium carbonate and magnesium hydroxide for precipitation, thereby reducing the hardness of the wastewater. At the same time, an exothermic reaction is generated to allow heat to enter the charging tube through the exothermic hole and enter the second air intake pipe for heat compensation. The wastewater concentrate passes through the purification tank and reacts with iron to adsorb heavy metal ions in the wastewater and generate ferroferric oxide co-precipitation, removing pollutants from the wastewater and producing hydrogen through redox reaction. The hydrogen enters the second air intake pipe through the energy recovery pipe for further heat compensation. Step 4: Second-effect and third-effect evaporation. The wastewater continues to evaporate in the second-effect evaporator to produce more steam and more concentrated liquid. The concentrated liquid in the second-effect evaporator enters the third-effect evaporator through the second softening part, charging part, and purification part. The secondary steam generated by the second-effect evaporator enters the third-effect evaporator through the second utilization part to further heat the wastewater. In the third-effect evaporator, the wastewater is evaporated to a higher concentration to form a concentrated liquid. Step 5: Condensation and recovery treatment. The secondary steam generated by the triple-effect evaporator enters the condenser through the steam pipe and is cooled by cooling water to become condensed water. The condensed water is reused and discharged to the sewage treatment plant for further treatment. The concentrated liquid discharged from the concentrated liquid pipe at the bottom of the triple-effect evaporator is further crystallized and the crystal salt is separated through a thickening kettle, a centrifuge and other equipment for recovery treatment.

[0018] (III) Beneficial effects Compared with the prior art, the present invention provides a three-effect evaporation concentrated wastewater treatment equipment and process, which has the following beneficial effects: 1. The three-effect evaporation concentrated wastewater treatment equipment and process adopts the method of compensating the secondary steam energy to improve the evaporation efficiency. By setting up a softening part and a charging part, the heat generated by the reaction of the wastewater concentrate and the calcium oxide particles is utilized to pass the heat release hole into the charging pipe, and then into the second air inlet pipe to perform heat compensation for the secondary steam, thereby reducing the energy attenuation of the secondary steam when flowing in each effect evaporator, improving the evaporation efficiency of the second effect evaporator and the three effect evaporator, and ensuring that the entire three-effect evaporation system can efficiently treat wastewater to meet the needs of industrial production.

[0019] 2. The three-effect evaporation and concentration wastewater treatment equipment and process reduces the hardness of wastewater and improves the treatment quality. The transfer pipe of the softening part is matched with the insulation tank. The wastewater concentrate reacts with the calcium oxide particles at the reaction port of the transfer pipe to generate calcium hydroxide. The calcium hydroxide reacts with the magnesium bicarbonate substance in the wastewater to generate calcium carbonate and magnesium hydroxide precipitation, which reduces the hardness of the wastewater. This is beneficial to subsequent evaporation treatment, reduces the risk of equipment scaling, improves the quality of wastewater treatment, and extends the service life of the equipment.

[0020] 3. The three-effect evaporation concentration wastewater treatment equipment and process removes pollutants in wastewater and reduces environmental pollution. In the purification tank of the purification unit, the iron plate and the wastewater undergo an oxidation-reduction reaction, and the generated ferroferric oxide adsorbs heavy metal ions in the wastewater and co-precipitates. The precipitated pollutants are intermittently discharged through the discharge pipe 2, which effectively removes pollutants in the wastewater, reduces the discharge of harmful substances in the wastewater, reduces pollution to the environment, and meets environmental protection requirements.

[0021] 4. The three-effect evaporation concentrated wastewater treatment equipment and process adopts the method of producing hydrogen to achieve energy complementation. The utilization part produces hydrogen through oxidation-reduction reaction. The hydrogen enters the second air inlet pipe through the energy return pipe to complement the energy of the secondary steam. It not only supplements the energy of the secondary steam, but also realizes the comprehensive utilization of energy, improves energy utilization rate and reduces operating costs.

[0022] 5. The three-effect evaporation concentrated wastewater treatment equipment and process ensures the thermal stability of each link and improves the stability of the system. Softening, charging, purification and utilization parts are set in the first-effect and second-effect evaporators to continuously perform thermal compensation, softening and purification on the secondary steam and concentrated liquid, ensuring the thermal stability of the wastewater concentrate and secondary steam in each link of the three-effect evaporation, reducing the uneven temperature and pressure distribution in each effect evaporator, improving the stability of the entire treatment system, and ensuring the normal operation and service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of a triple-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 2This is a schematic diagram of the structure of a first-effect evaporator of a three-effect evaporation concentrated wastewater treatment equipment proposed by the present invention; Figure 3 This is a schematic diagram of the structure of the softening part of a triple-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 4 This is a connection diagram of the purification part and the utilization part of a triple-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 5 This is a connection diagram of the softening part and the charging part of a triple-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 6 This is a schematic diagram of the structure of the charging part of a three-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 7 This is a schematic diagram of the structure of the purification part of a three-effect evaporation and concentration wastewater treatment equipment proposed by the present invention; Figure 8 This is a structural schematic diagram of a motor and a liquid level sensor for a triple-effect evaporation concentration wastewater treatment device proposed by the present invention.

[0024] In the figure: 1. first-effect evaporator; 2. second-effect evaporator; 3. third-effect evaporator; 4. softening unit; 41. transfer pipe; 42. transfer pump; 43. reaction port; 44. insulation tank; 45. sedimentation tank; 46. discharge pipe 1; 47. valve 1; 48. rack; 49. tank cover; 410. filter 1; 5. charging unit; 51. partition plate; 52. reaction hole; 53. charging pipe; 54. heat release hole; 55, plug valve; 56, extension valve stem; 57, motor; 58, liquid level sensor; 6, purification unit; 61, purification tank; 62, discharge pipe 2; 63, valve 2; 64, filter 2; 65, second feed pipe; 66, iron plate; 7, utilization unit; 71, second air inlet pipe; 72, energy return pipe; 73, valve 3; 74, sealing cover; 8, air pipe; 9, steam pipe; 10, concentrate pipe. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-8The present invention provides a technical solution: a three-effect evaporation concentrated wastewater treatment equipment, comprising a first-effect evaporator 1, a second-effect evaporator 2 and a three-effect evaporator 3. The softening part 4 of this case is installed at the lower side of the first-effect evaporator 1 and the second-effect evaporator 2, and is used to reduce the hardness of the flowing wastewater and regenerate heat energy. The charging part 5 of this case is installed in the softening part 4, and is used to compensate the secondary steam energy loss with the regenerated heat energy. The purification part 6 of this case is installed at the end of the softening part 4 to remove pollutants in the wastewater by co-precipitation. The utilization part 7 of this case is installed on the upper side of the first-effect evaporator 1 and the second-effect evaporator 2, and hydrogen is produced by oxidation-reduction reaction to complement the secondary steam energy.

[0027] In the present invention, in order to promote the softening of wastewater, the softening part 4 of this case includes a transfer pipe 41, which is a serpentine structure. One end of the transfer pipe 41 is connected and installed at the bottom of the first-effect evaporator 1. A transfer pump 42 is installed at the bent part of the transfer pipe 41. The transfer pipe 41 and the inlet and outlet of the transfer pump 42 are connected. Reaction ports 43 are opened on both sides of the straight end of the transfer pipe 41. The straight end of the transfer pipe 41 is fixedly sleeved with an insulation tank 44. The reaction port 43 is located inside the insulation tank 44. The bottom of the insulation tank 44 is connected and installed with a sedimentation tank 45. The bottom of the sedimentation tank 45 is connected and installed with a discharge pipe 46. The discharge pipe 46 is connected and installed. A valve 47 is installed on 46, and the valve is used for intermittent discharge of sediment. A frame 48 is installed on the outer wall of the insulation tank 44, and two tank covers 49 are symmetrically arranged on the top of the insulation tank 44. A filter 410 is installed on the side wall of the insulation tank 44. The filter 410 filters the sediment in the insulation tank 44 to prevent it from flowing with the wastewater. The filter 410 is also installed at the straight end of the transfer pipe 41 and is connected to the transfer pipe 41. The insulation tank 44 is a conical structure, and the valve 47 is a solenoid valve. There are two softening parts 4, and the transfer pipe 41 in the other softening part 4 is connected and installed at the bottom of the second-effect evaporator 2.

[0028] In this embodiment, in order to supply the exothermic reaction energy to the secondary steam, the charging part 5 of this case includes a partition plate 51, which is fixedly connected to the middle of the inner wall of the insulation tank 44 on the first-effect evaporator 1, and the bottom of the partition plate 51 is fixedly connected to the top of the outer wall of the transfer tube 41 on the first-effect evaporator 1. A reaction hole 52 is opened in the middle of the partition plate 51, and a charging tube 53 is installed on the inner wall of the reaction hole 52. The outer wall of the charging tube 53 is opened with a heat release hole 54, and a plug valve 55 is installed on the charging tube 53. The valve is a common manual valve. The plug valve 55 is arranged between the inner walls of the reaction hole 52. The valve shaft of the plug valve 55 is fixedly connected with an extension valve stem 56. The end of the extension valve stem 56 is provided with a motor 57 and fixedly connected to the output shaft of the motor 57. The plug valve 55 prevents the wastewater in the charging tube 53 from continuing to rise. A liquid level sensor 58 is arranged on the charging tube 53. The top of 3 is fixed and penetrates to the outside of the top of the partition plate 51, the motor 57 is installed on the frame 48, the extended valve stem 56 movably penetrates the outer wall of the insulation tank 44 on the first-effect evaporator 1, the sensing end of the liquid level sensor 58 penetrates the insulation tank 44 on the first-effect evaporator 1 and penetrates into the charging tube 53, the liquid level sensor 58 is installed on the frame 48 and is located below the motor 57, the liquid level sensor 58 is electrically connected to the motor 57, and the motor 57 is synchronously opened or closed by detecting the height of the wastewater deposited in the charging tube 53. The two tank covers 49 are respectively installed on both sides of the partition plate 51 and between the inner wall of the insulation tank 44. The tank cover 49 is used to seal the insulation tank 44 and open the insulation tank 44 to add calcium oxide particles and facilitate cleaning of the tank. There are two charging parts 5, and the other charging part 5 is installed on the insulation tank 44 of the second-effect evaporator 2 and on the top of the outer wall of the transfer tube 41 on the second-effect evaporator 2.

[0029] It is worth noting that in order to further remove pollutants in the wastewater, the purification part 6 of this case includes a purification tank 61, which is connected to the straight end of the transfer pipe 41 installed on the first-effect evaporator 1, and the bottom of the purification tank 61 is connected to a discharge pipe 62, and a valve 63 is installed on the discharge pipe 62. The valve discharges the precipitated pollutants through an intermittent setting. The valve 63 is a solenoid valve. A filter 64 is installed on one side of the outer wall of the purification tank 61. The filter 64 filters the precipitated pollutants to prevent them from flowing with the wastewater to the next evaporator. Two feed pipes 65 are installed on the filter 64, and an iron plate 66 is fixedly connected between the inner walls of the purification tank 61.

[0030] Further, hydrogen is produced through high-temperature redox reaction to complement the energy of secondary steam. The utilization part 7 in this case includes two air inlet pipes 71. The two air inlet pipes 71 are of a serpentine structure. The bent ends of the two air inlet pipes 71 are connected and installed on the top of the first-effect evaporator 1. The straight ends of the two air inlet pipes 71 are connected and installed with the top of the charging pipe 53. The straight ends of the two air inlet pipes 71 are connected and installed with two energy return pipes 72. Valve three 73 is installed on the two energy return pipes 72. Valve three 73 is a solenoid valve. The valve prevents the wastewater from continuing to flow up. The two energy return pipes 72 are made of transparent materials. The liquid level height in the energy return pipe 72 can be observed from the outside. The bottom ends of the two energy return pipes 72 are connected and installed with a sealing cover 74, which is installed at the top tank mouth of the purification tank 61.

[0031] It is worth noting that in order to provide secondary steam heat compensation in each evaporation link and reduce the energy attenuation efficiency of secondary steam, the number of purification parts 6 and utilization parts 7 in this case is two each. The other purification part 6 and utilization part 7 are respectively installed at the straight end of the transfer pipe 41 on the second effect evaporator 2 and the top of the second effect evaporator 2. The straight end of the second air inlet pipe 71 on the first effect evaporator 1 is connected with the second effect evaporator 2, the second feed pipe 65 on the first effect evaporator 1 is connected with the second effect evaporator 2, the straight end of the second air inlet pipe 71 on the second effect evaporator 2 is connected with the three-effect evaporator 3, the two feed pipes 65 on the second effect evaporator 2 are connected with the three-effect evaporator 3, the outer wall of the first effect evaporator 1 is connected with a gas pipe 8, and the gas pipe 8 is used to connect the raw steam to enter. The top of the three-effect evaporator 3 is connected with a steam pipe 9, and the steam pipe 9 is used to connect the condenser. The bottom of the three-effect evaporator 3 is connected with a concentrated liquid pipe 10, and the concentrated liquid pipe 10 is used to discharge the concentrated liquid and transfer it to the crystallization equipment for further treatment.

[0032] A process for treating wastewater using a triple-effect evaporation concentration device comprises the following steps: Step 1: Pretreatment: The wastewater first enters the pretreatment stage, and removes suspended matter, grease and other impurities through filtration and pH adjustment measures to ensure that the wastewater is suitable for entering the evaporator. Calcium oxide particles are filled on both sides of the insulation tank 44 isolated by the partition plate 51; Step 2: First-effect evaporation, the pretreated wastewater enters the first-effect evaporator 1, the raw steam from the boiler enters the heating chamber from the gas pipe 8 and is heated to boiling, generating a large amount of steam, the steam rises and enters the evaporation chamber, and is separated from the concentrated liquid, the concentrated liquid flows out from the bottom of the evaporation chamber, and enters the insulation tank 44 and the purification tank 61 through the transfer pipe 41 and the transfer pump 42 connected to the first-effect evaporator 1 and enters the second-effect evaporator 2, the secondary steam flows out from the second air inlet pipe 71 of the first-effect evaporator 1 and enters the second-effect evaporator 2 as a heating heat source; Step 3: heat compensation and wastewater purification. The wastewater concentrate reacts with the calcium oxide particles through the reaction port 43 of the transfer tube 41 to generate calcium hydroxide, and reacts with the magnesium bicarbonate substance in the wastewater to generate calcium carbonate and magnesium hydroxide for precipitation, thereby reducing the hardness of the wastewater. At the same time, an exothermic reaction is generated to allow heat to enter the charging tube 53 through the heat release hole 54 and enter the second air intake pipe 71 for heat compensation. The wastewater concentrate passes through the purification tank 61 and reacts with iron to adsorb heavy metal ions in the wastewater and generate ferroferric oxide co-precipitation, removing pollutants from the wastewater and producing hydrogen through redox reaction. The hydrogen enters the second air intake pipe 71 through the energy recovery pipe 72 for further heat compensation. Step 4: Second-effect and third-effect evaporation. The wastewater continues to evaporate in the second-effect evaporator 2 to produce more steam and more concentrated liquid. The concentrated liquid in the second-effect evaporator 2 enters the third-effect evaporator 3 through the second softening section 4, the charging section 5, and the purification section 6. The secondary steam generated by the second-effect evaporator 2 enters the third-effect evaporator 3 through the second utilization section 7 to further heat the wastewater. In the third-effect evaporator 3, the wastewater is evaporated to a higher concentration to form a concentrated liquid. Step 5: Condensation and recovery treatment. The secondary steam generated by the triple-effect evaporator 3 enters the condenser through the steam pipe 9 and is cooled by cooling water to become condensed water. The condensed water is reused and discharged to the sewage treatment plant for further treatment. The concentrated liquid discharged from the concentrated liquid pipe 10 at the bottom of the triple-effect evaporator 3 is further crystallized, and the crystal salt is separated by a thickening kettle, a centrifuge and other equipment for recovery treatment.

[0033] Working principle: wastewater enters the first-effect evaporator 1 and reacts with the raw steam entering from the gas pipe 8 for the first time. The generated wastewater concentrate is pumped into the transfer pipe 41 through the transfer pump 42, and reacts with the calcium oxide particles filled in the insulation tank 44 at the reaction port 43 to generate calcium hydroxide, and reacts with the magnesium bicarbonate substance in the wastewater to generate calcium carbonate and magnesium hydroxide for precipitation, thereby reducing the hardness of the wastewater, which is beneficial to the subsequent wastewater treatment quality. The precipitate accumulates continuously and precipitates in the precipitation tank 45. At the same time, an exothermic reaction is generated according to the reaction equation CaO+H2O=Ca(OH)2, so that the heat is applied to the wastewater. The water itself is reheated to maintain the temperature of the wastewater during transportation in the transfer pipe 41, and heat is accumulated through the insulation tank 44, so that the hot gas enters the charging pipe 53 through the heat release hole 54 and rises to the second air inlet pipe 71 for heat compensation with the secondary steam. In order to avoid the problem of wastewater overflowing into the charging pipe 53 due to continuous heat release in the insulation tank 44, the height of the wastewater in the charging pipe 53 is detected by the sensing end of the liquid level sensor 58. When the threshold height is reached, a sensing signal is sent to intermittently start the motor 57, so that the extended valve stem 56 rotates and the stopcock 55 is closed through the valve shaft to prevent the wastewater from continuing to flow up and overflow into the second air inlet pipe 71.

[0034] The wastewater concentrate continues to flow out from the filter 1 410 to the purification tank 61, and the iron plate 66 blocks the wastewater from sinking to the bottom of the purification tank 61. The wastewater passes through the bottom of the purification tank 61 and flows out from the filter 2 64 to the second feed pipe 65, and then enters the second effect evaporator 2. The wastewater reacts with the iron plate 66 in the purification tank 61, and an oxidation-reduction reaction occurs according to the chemical equation 3Fe+4H2O(g) high temperature=Fe3O4+4H2, generating ferroferric oxide to adsorb heavy metal ions in the wastewater and co-precipitate, and the generated hydrogen enters the second air inlet pipe 71 through the energy recovery pipe 72 for further heat compensation, maintaining the heat of the secondary steam when flowing in the second air inlet pipe 71, and the precipitated pollutants will accumulate at the bottom of the purification tank 61 and be intermittently discharged through the discharge pipe 2 62. The valve 3 73 is used to ensure the efficiency of the unidirectional upward flow of hydrogen and prevent the wastewater from overflowing from the energy recovery pipe 72 into the second air inlet pipe 71.

[0035] Similarly, the softening part 4, charging part 5, purification part 6 and utilization part 7 connected to the second-effect evaporator 2 can continue to perform further heat compensation, softening and purification on the secondary steam and the concentrated liquid through the above steps, thereby ensuring the heat of the wastewater concentrated liquid and the secondary steam in each link of the three-effect evaporation, reducing the energy attenuation efficiency, and improving the processing efficiency and processing stability.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims

1. A triple-effect evaporation and concentration wastewater treatment equipment, characterized in that: include: A first effect evaporator (1), a second effect evaporator (2), and a third effect evaporator (3); A softening unit (4) is installed at the lower side of the first-effect evaporator (1) and the second-effect evaporator (2) and is used to reduce the hardness of the flowing wastewater and regenerate heat energy; An energy charging unit (5) is installed in the softening unit (4) and is used to compensate for the secondary steam energy loss with the regenerated heat energy; A purification section (6) installed at the end of the softening section (4) for removing pollutants from the wastewater by co-precipitation; The utilization part (7) is installed on the upper side of the first-effect evaporator (1) and the second-effect evaporator (2), and produces hydrogen through redox reaction to complement the energy of the secondary steam.

2. A triple-effect evaporation concentrated wastewater treatment equipment according to claim 1, characterized in that: The softening part (4) comprises a material transfer pipe (41), the material transfer pipe (41) is a serpentine structure, one end of the material transfer pipe (41) is connected and installed at the bottom of the first-effect evaporator (1), a material transfer pump (42) is installed at the bent part of the material transfer pipe (41), the inlet and outlet of the material transfer pipe (41) and the material transfer pump (42) are connected, reaction ports (43) are provided on both sides of the straight end of the material transfer pipe (41), a heat preservation tank (44) is fixedly provided on the straight end of the material transfer pipe (41), and the reaction port (43) is located inside the heat preservation tank (44). The bottom of the heat preservation tank (44) is connected to a sedimentation tank (45), the bottom of the sedimentation tank (45) is connected to a discharge pipe (46), the discharge pipe (46) is installed with a valve (47), the outer wall of the heat preservation tank (44) is installed with a frame (48), the top of the heat preservation tank (44) is symmetrically provided with two tank covers (49), the side wall of the heat preservation tank (44) is installed with a filter (410), and the filter (410) is also installed at the straight end of the transfer pipe (41) and is connected to the transfer pipe (41).

3. A triple-effect evaporation concentrated wastewater treatment equipment according to claim 2, characterized in that: The heat preservation tank (44) is a conical structure, the valve one (47) is a solenoid valve, there are two softening parts (4), and the transfer pipe (41) in the other softening part (4) is connected and installed at the bottom of the second-effect evaporator (2).

4. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 3, characterized in that: The charging part (5) comprises a material separator (51), wherein the material separator (51) is fixedly connected to the middle of the inner wall of the heat preservation tank (44) on the first-effect evaporator (1), the bottom of the material separator (51) is fixedly connected to the top of the outer wall of the material transfer tube (41) on the first-effect evaporator (1), a reaction hole (52) is opened in the middle of the material separator (51), a charging tube (53) is installed on the inner wall of the reaction hole (52), a heat release hole (54) is opened on the outer wall of the charging tube (53), a plug valve (55) is installed on the charging tube (53), the plug valve (55) is arranged between the inner walls of the reaction hole (52), the valve shaft of the plug valve (55) is fixedly connected to an extension valve stem (56), a motor (57) is arranged at the end of the extension valve stem (56) and is fixedly connected to the output shaft of the motor (57), and a liquid level sensor (58) is arranged on the charging tube (53).

5. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 4, characterized in that: The top end of the charging tube (53) is fixedly passed through the top outer side of the partition plate (51); the motor (57) is mounted on the frame (48); the extension valve stem (56) movably passes through the outer wall of the insulation tank (44) on the first-effect evaporator (1); the sensing end of the liquid level sensor (58) passes through the insulation tank (44) on the first-effect evaporator (1) and passes through the inside of the charging tube (53); the liquid level sensor (58) is mounted on the frame (48) and is located below the motor (57); the two tank covers (49) are respectively mounted on both sides of the partition plate (51) and between the inner wall of the insulation tank (44); there are two charging parts (5); the other charging part (5) is mounted on the insulation tank (44) of the second-effect evaporator (2) and on the top of the outer wall of the transfer tube (41) on the second-effect evaporator (2).

6. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 5, characterized in that: The purification part (6) comprises a purification tank (61), the purification tank (61) being connected to the straight end of the transfer pipe (41) installed on the first-effect evaporator (1), the bottom of the purification tank (61) being connected to a second discharge pipe (62), the second discharge pipe (62) being installed with a second valve (63), the second valve (63) being a solenoid valve, one side of the outer wall of the purification tank (61) being connected to a second filter (64), the second filter (64) being connected to two feed pipes (65), and an iron plate (66) being fixedly connected between the inner walls of the purification tank (61).

7. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 6, characterized in that: The utilization part (7) comprises two air inlet pipes (71), the two air inlet pipes (71) are of a serpentine structure, the bent ends of the two air inlet pipes (71) are connected and installed on the top of the first-effect evaporator (1), the straight ends of the two air inlet pipes (71) are connected and installed with the top of the energy charging pipe (53), the straight ends of the two air inlet pipes (71) are connected and installed with two energy return pipes (72), the two energy return pipes (72) are both installed with valve three (73), the valve three (73) is a solenoid valve, the two energy return pipes (72) are both made of transparent material, the bottom ends of the two energy return pipes (72) are connected and installed with a sealing cover (74), and the sealing cover (74) is installed on the top tank opening of the purification tank (61).

8. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 7, characterized in that: The number of the purification section (6) and the utilization section (7) is two, and the other purification section (6) and the utilization section (7) are respectively installed at the straight end of the transfer pipe (41) on the second effect evaporator (2) and the top of the second effect evaporator (2). The straight end of the second air inlet pipe (71) on the first effect evaporator (1) is connected to the second effect evaporator (2). The second feed pipe (65) on the first effect evaporator (1) is connected to the second effect evaporator (2). The straight end of the second air inlet pipe (71) on the second effect evaporator (2) is connected to the third effect evaporator (3). The second feed pipe (65) on the second effect evaporator (2) is connected to the third effect evaporator (3).

9. A triple-effect evaporation and concentration wastewater treatment equipment according to claim 8, characterized in that: The outer wall of the first-effect evaporator (1) is connected to a gas pipe (8), the top of the three-effect evaporator (3) is connected to a steam pipe (9), and the bottom of the three-effect evaporator (3) is connected to a concentrated liquid pipe (10).

10. A process for treating wastewater using a triple-effect evaporation concentration device, according to claim 9, characterized in that: The following steps are involved: Step 1: Pretreatment: The wastewater first enters the pretreatment stage, and suspended matter, grease and other impurities are removed by filtering and adjusting the pH value to ensure that the wastewater is suitable for entering the evaporator. Calcium oxide particles are filled on both sides of the insulation tank (44) separated by the partition plate (51); Step 2: first-effect evaporation, the pretreated wastewater enters the first-effect evaporator (1), the raw steam from the boiler enters the heating chamber from the gas pipe (8) and is heated to boiling, generating a large amount of steam, the steam rises and enters the evaporation chamber, and is separated from the concentrated liquid, the concentrated liquid flows out from the bottom of the evaporation chamber, passes through the transfer pipe (41) and the transfer pump (42) connected to the first-effect evaporator (1), enters the insulation tank (44), the purification tank (61) and enters the second-effect evaporator (2), the secondary steam flows out from the second air inlet pipe (71) of the first-effect evaporator (1) and enters the second-effect evaporator (2) as a heating heat source; Step 3: heat compensation and wastewater purification. The wastewater concentrate reacts with the calcium oxide particles through the reaction port (43) of the transfer tube (41) to generate calcium hydroxide, and reacts with the magnesium bicarbonate substance in the wastewater to generate calcium carbonate and magnesium hydroxide for precipitation, thereby reducing the hardness of the wastewater. At the same time, an exothermic reaction is generated to allow heat to enter the charging tube (53) through the heat release hole (54) and enter the second air intake pipe (71) for heat compensation. The wastewater concentrate passes through the purification tank (61) to react with iron to adsorb heavy metal ions in the wastewater and generate ferroferric oxide co-precipitation, remove pollutants in the wastewater, and produce hydrogen through a redox reaction. The hydrogen enters the second air intake pipe (71) through the energy recovery pipe (72) for further heat compensation. Step 4: Second-effect and third-effect evaporation. The wastewater continues to evaporate in the second-effect evaporator (2) to produce more steam and more concentrated liquid. The concentrated liquid in the second-effect evaporator (2) enters the third-effect evaporator (3) through the second softening section (4), the charging section (5), and the purification section (6). The secondary steam generated by the second-effect evaporator (2) enters the third-effect evaporator (3) through the second utilization section (7) to further heat the wastewater. In the third-effect evaporator (3), the wastewater is evaporated to a higher concentration to form a concentrated liquid. Step 5: Condensation and recovery treatment. The secondary steam generated by the triple-effect evaporator (3) enters the condenser through the steam pipe (9) and is cooled by cooling water to become condensed water. The condensed water is reused and discharged to the sewage treatment plant for further treatment. The concentrated liquid discharged from the concentrated liquid pipe (10) at the bottom of the triple-effect evaporator (3) is further crystallized and the crystal salt is separated by a thickening kettle, a centrifuge and other equipment for recovery treatment.

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