CN110921744A - High-salt-content wastewater treatment method - Google Patents
High-salt-content wastewater treatment method Download PDFInfo
- Publication number
- CN110921744A CN110921744A CN201911283864.8A CN201911283864A CN110921744A CN 110921744 A CN110921744 A CN 110921744A CN 201911283864 A CN201911283864 A CN 201911283864A CN 110921744 A CN110921744 A CN 110921744A
- Authority
- CN
- China
- Prior art keywords
- stage
- evaporation
- evaporation concentration
- water
- material liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
The invention discloses a high-salt-content wastewater treatment method, wherein raw material liquid generates condensed water after n-stage continuous evaporation concentration and is saturated in the nth stage to separate out crystal salt, the feed liquid is heated to 80-100 ℃ by a heater in the first-stage evaporation concentration, the feed liquid is further evaporated and concentrated by the second-stage evaporation concentration by using the self high temperature of the feed liquid, the heat generated by the phase change of the steam generated in the m-2-stage evaporation concentration process is used as a main heating heat source in the mth-2-stage evaporation concentration, the feed liquid after evaporation concentration flows into the m-1-stage from the m-2-stage, the condensed water generated by the phase change of the steam generated in the processes from the third-stage evaporation concentration to the nth-stage evaporation concentration is used as produced water to be discharged, the steam generated in the processes of the n-1-stage and the nth-stage evaporation concentration is discharged, and m is not less than 3. N is more than or equal to 6 and less than or equal to 20. The preheating of the raw material liquid shortens the time for heating the material liquid in the first stage to the set temperature, and the steam generated in the m-2 stage evaporation concentration process is used for heating the material liquid in the m stage, so that the waste of energy is avoided.
Description
Technical Field
The invention relates to a method for treating salt-containing wastewater, in particular to a method for treating high-salt-content wastewater.
Background
In the exploration and development process of petroleum and natural gas, various substances are required to be added in an oil field and a gas field in the development process, and three types of wastewater, namely drilling wastewater, fracturing flow-back fluid and gas field produced water with complex components and high salt content are generated, and the three types of wastewater are collectively called as oil and gas field wastewater. The oil and gas field wastewater is mainly characterized by high COD, high suspended matter and high salinity, belongs to refractory organic wastewater with high salt content, and causes a lot of environmental hazards if the wastewater is directly discharged without being treated, and the standardized standard treatment of the wastewater is a hotspot and a difficulty in the research of the oil and gas field wastewater.
Mechanical Vapor Recompression (MVR) evaporator, it utilizes the high-energy efficiency vapor compressor compression evaporation to produce the secondary steam, converts the electric energy into heat energy, improves the enthalpy value of secondary steam, is thrown into the evaporating chamber by the secondary steam that improves heat energy and heats, carries out cyclic utilization with the existing heat energy of secondary steam to can be at the outside bright steam that does not increase, rely on the evaporimeter self-loopa to realize the concentrated purpose of evaporation. However, the MVR technology has large investment waste, occupied area and operation cost, and in addition, the equipment is complex to install, has high cost on the requirement of the oil and gas field wastewater, is not suitable for the oil and gas field movement and has a large amount of wastewater generated projects. Therefore, how to effectively treat the high-salinity wastewater is an urgent problem to be solved.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention provides a method for treating high-salt-content wastewater.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a high-salt-content wastewater treatment method comprises the steps that raw material liquid generates condensed water after n-level continuous evaporation concentration, the raw material liquid is saturated in the n-level to separate out crystal salt, the first-level evaporation concentration utilizes a heater to heat the raw material liquid to 80-100 ℃, the second-level evaporation concentration utilizes the high temperature of the fed material liquid to further carry out evaporation concentration, the m-level evaporation concentration utilizes the heat generated by the phase change of water vapor generated in the m-2-level evaporation concentration process as a main heating heat source, the evaporated and concentrated raw material liquid flows into the m-1-level from the m-2-level, the condensed water generated by the phase change of the water vapor generated in the processes from the third-level evaporation concentration to the n-level evaporation concentration is used as produced water to be discharged, the water vapor generated in the processes of the n-1-level evaporation concentration and the n-level evaporation concentration is discharged, and m is not less than 3.
Further, n in the n-stage continuous evaporation concentration is more than or equal to 6 and less than or equal to 20.
Furthermore, the evaporation concentration process also adopts an aeration mode to generate micro bubbles in the feed liquid of each stage of evaporation concentration, so that the feed liquid is heated more uniformly, and the mobility between water molecules and water vapor molecules at a phase interface is increased, thereby improving the evaporation efficiency of the equipment.
Further, the air flow is 95-125L/h.
Further, a temperature gradient is formed when the evaporation concentration of n stages is stabilized.
Furthermore, the raw material liquid exchanges heat with condensed water which is generated in the evaporation concentration process from the third stage to the nth stage and carries energy, so that the raw material liquid is preheated for the first time; the raw material liquid after the first preheating and the steam bubbles generated in the evaporation concentration process of the (n-1) th level and the nth level are converted into hot air to be heated, so that the second preheating of the raw material liquid is realized.
Furthermore, the n-stage continuous evaporative concentration is realized by an n-stage evaporative concentration system, the n-stage evaporative concentration system comprises n evaporative water tanks, a heater, an overflow pipe, a main gas collecting pipe, a water production pipe, a second feeding hole and a raw material liquid pipe, the evaporative water tanks are sequentially connected in series to form the n-stage evaporative system, the overflow pipe is arranged in each stage of evaporative water tank and is used for enabling the material liquid to flow into the next stage of evaporative water tank, the main gas collecting pipe is arranged on each stage of evaporative water tank and is used for discharging water vapor generated by the current stage, the heater is arranged in the first stage evaporative water tank, the second feeding hole is arranged on the first stage evaporative water tank, the raw material liquid pipe is communicated with the second feeding hole, the third heat exchanger is arranged in the third stage to the n-stage evaporative water tank and is used for receiving the water vapor discharged by the main gas collecting pipe in the previous stage, the water production pipe is used, the heat generated by the phase change of the water vapor discharged from the m-2 stage main gas collecting pipe in the m-stage third heat exchanger is used as a heat source for main heating of the feed liquid in the m-stage, the uncondensed water vapor in the third heat exchanger is converged into the main gas collecting pipe of the current stage, and the water vapor and air generated in the n-1 stage and the n stage are discharged through the main gas collecting pipes of the same stage.
And the aeration device comprises an aeration membrane component arranged in each stage of evaporation water tank and an air pipe which is connected with the aeration membrane component and provides air for the aeration membrane component.
Compared with the prior art, the invention has the following beneficial effects:
(1) according to the invention, by utilizing the principle of air moisture absorption and entrainment, air is introduced into the aeration device, and by utilizing the material of the aeration membrane component as the hydrophobic hollow fiber membrane, the air passes through the aeration membrane component to form micro bubbles with air in the feed liquid, so that the feed liquid to be heated is more uniform, and the fluidity between water molecules and water vapor molecules at a phase interface is increased, thereby improving the evaporation efficiency of the equipment.
(2) According to the invention, by utilizing the principle that the moisture absorption capacity of air at high temperature is greater than that of air at low temperature, micro-bubbles are formed in the feed liquid of the evaporation water tank through the aeration membrane component, meanwhile, the heater is arranged in the first-stage evaporation water tank, and other m (m is more than or equal to 3 and less than or equal to n) stage evaporation water tanks are heated by using water vapor generated by the m-2 stage evaporation water tank, so that the temperature of the whole system is increased, the air moisture absorption capacity of the whole system is increased, and the evaporation capacity of the whole system is improved.
(3) According to the invention, n evaporation water tanks are sequentially connected in series to form n-stage evaporation, and the feed liquid sequentially passes through the evaporation water tanks connected in series to form a step-by-step evaporation concentration mode. In addition, the solid-liquid quick grading separation effectively avoids the problem of blockage of the equipment pipeline by the crystallized salt.
(4) The invention uses the heat generated by the phase change of the vapor generated in the evaporation concentration process of the feed liquid in the m-2 level in the heat exchanger in the m level as a heat source from the m (m is more than or equal to 3 and less than or equal to 20) level, and reduces the energy consumption of the evaporation device by using the multi-effect evaporation principle. Meanwhile, the feed liquid in the second stage is further evaporated and concentrated by utilizing the high temperature of the feed liquid, a large amount of heat is taken away along with the evaporation and concentration, so that the temperature difference between the feed liquid entering the third stage and the water vapor generated in the first stage is enlarged, the utilization rate of the heat carried by the water vapor generated in the first stage is improved, the feed liquid in the mth stage is heated by utilizing the water vapor generated in the m-2 stage, and the utilization rate of the heat carried by the water vapor is also improved by utilizing the larger temperature difference between the water vapor generated in the m-2 stage and the feed liquid in the mth stage.
(5) The invention utilizes the membrane aeration device to stir the feed liquid, thereby reducing the pollution and the scaling of each part in the evaporator on the one hand, strengthening the heat transfer on the other hand and improving the efficacy of the evaporator.
(6) The raw material liquid pipe is sequentially provided with a first heat exchanger and a second heat exchanger along the raw material liquid flow direction to preheat the raw material liquid entering a first-stage evaporation water tank, the raw material liquid and condensed water from a water production pipe and uncooled water vapor and hot air from a mixed gas pipe are subjected to heat exchange in the first heat exchanger to preheat the raw material liquid for the first time, and the raw material liquid and the water vapor and the hot air from n-1 stage and n-stage main gas collecting pipes are subjected to heat exchange in the second heat exchanger to preheat the raw material liquid for the second time. The raw material liquid is preheated, so that the time for heating the material liquid in the first stage to the set temperature is shortened, and the heat energy in the system is fully utilized, so that the energy waste is avoided.
Drawings
FIG. 1 is a schematic diagram of a method for treating wastewater with high salt content according to the invention.
FIG. 2 is a schematic view of a first stage evaporation water tank according to the present invention.
FIG. 3 is a schematic view of an evaporating water tank of any stage from the third stage to the (n-1) th stage in the present invention.
FIG. 4 is a schematic view of the nth stage evaporation water tank of the present invention.
Wherein, the names corresponding to the reference numbers are:
1-an evaporation water tank, 2-a heater, 3-an aeration device, 4-an overflow pipe, 5-a main gas collecting pipe, 6-a first auxiliary gas collecting pipe, 7-a second auxiliary gas collecting pipe, 8-a water collecting pipe, 9-a water producing pipe, 10-a third heat exchanger, 11-a second heat exchanger, 12-a first heat exchanger, 13-an air pipe, 15-a first feeding hole, 14-a second feeding hole, 16-a first outlet, 17-a second outlet, 18-a third outlet, 19-a collecting tank, 20-a mixed air pipe, 21-a raw material liquid pipe and 22-an aeration membrane component.
Detailed Description
The present invention will be further described with reference to the following description and examples, which include but are not limited to the following examples.
Examples
As shown in fig. 1 to 4, the present embodiment discloses a method for treating high-salinity wastewater to form nine-stage evaporation when n is 9, and the present embodiment includes 9 evaporation water tanks 1, an overflow pipe 4, a raw material liquid pipe 21, a heater 2, a water collecting pipe 8, a water producing pipe 9, a main gas collecting pipe 5, a first auxiliary gas collecting pipe 6, a first outlet 16, a second inlet 14, and a third heat exchanger 10. Specifically, the system is a nine-stage evaporation system formed by sequentially connecting 9 evaporation water tanks in series, wherein the 9 evaporation water tanks can be sequentially connected in series from top to bottom, a first-stage evaporation water tank, a second-stage evaporation water tank and a third-stage evaporation water tank are sequentially connected in series in a first layer from top to bottom, a fourth-stage evaporation water tank, a fifth-stage evaporation water tank and a sixth-stage evaporation water tank are sequentially connected in series in a second layer, and a seventh-stage evaporation water tank, an eighth-stage evaporation water tank and a ninth-stage evaporation water tank are sequentially connected in series in a third layer; the 9 evaporation water tanks can be sequentially connected in series on the same plane, can be connected in series to form a row, and can also be connected in series to form a plurality of rows. In addition, the serial connection mode of the evaporation water tanks in the invention is not limited to the above cases, and can be adjusted according to actual situations.
Specifically, the nine-stage evaporative concentration system of the embodiment is further provided with an aeration device 3, wherein the aeration device comprises an aeration membrane assembly 22 and an air pipe 13, and the aeration membrane assembly is communicated with the air pipe. The evaporation water tank of each stage is internally provided with a main gas collecting pipe for discharging water vapor generated in the stage, and the main gas collecting pipes in the eighth stage and the ninth stage are combined. Third heat exchangers for receiving water vapor discharged by the main gas collecting pipes at the previous stage are arranged in the evaporation water tanks from the third stage to the ninth stage, a water collecting pipe and a first auxiliary gas collecting pipe are arranged at the bottom of each third heat exchanger, the first auxiliary gas collecting pipes in the third stage to the ninth stage are communicated with the main gas collecting pipes arranged at the same stage, and the water collecting pipes are communicated with the water production pipes; an overflow pipe for the feed liquid to flow into the next evaporation water tank is also arranged in each evaporation water tank. In addition, the raw material liquid pipe is provided with a first heat exchanger 12 and a second heat exchanger 11 in sequence on the pipeline according to the flow direction of the raw material liquid, the first heat exchanger is positioned in front of the second heat exchanger, and the first heat exchanger is connected with a water production pipe. The aeration membrane component and the third heat exchanger in each stage of evaporation water tank are arranged at intervals, the number of the aeration membrane component and the third heat exchanger in each stage of evaporation water tank is not limited to that shown in figure 1 and can be adjusted according to actual conditions, and the number of the third heat exchangers is not limited to that shown in figure 1 and can also be adjusted according to actual conditions.
Specifically, the first-stage evaporation water tank comprises a second feeding hole which is arranged on the first-stage evaporation water tank and used for feeding raw material liquid, a heater is further arranged in the first-stage evaporation water tank, the heater and the aeration membrane component are arranged at intervals, a main gas collecting pipe of the first-stage evaporation water tank is arranged at the top of the first-stage evaporation water tank, a water inlet of an overflow pipe arranged in the first-stage evaporation water tank is located at the bottom of the first-stage evaporation water tank, and a water outlet of the overflow pipe is located in the second-stage evaporation water tank and higher than. The number of heaters is not limited to that shown in fig. 1, and may be further adjusted according to the actual circumstances, and the heater may heat the raw material liquid directly by using electricity or by using steam, and the temperature of heating in the first-stage evaporation water tank is set to 80 to 100 ℃.
When preheated raw material liquid enters the first-stage evaporation water tank, the heater is started to heat the material liquid in the first stage, then air is introduced into the aeration membrane component through the air pipe, the aeration intensity of the aeration membrane component is controlled by adjusting the valve of the air compressor and the valve of the pneumatic valuator, the aeration membrane component is promoted to generate micro bubbles in the material liquid of each stage of evaporation water tank, the mobility between water molecules and water vapor molecules at a phase interface is increased, and the evaporation efficiency is improved. The hot air converted from the vapor and the micro-bubbles generated in the evaporation concentration process of the feed liquid in the first stage is sent into a third heat exchanger in the third stage through a main gas collecting pipe in the first stage, and the heated feed liquid in the first stage enters a second evaporation water tank through an overflow pipe.
Specifically, the main gas collecting pipe in the second stage penetrates through the bottom of the second-stage evaporation water tank and extends into the second-stage evaporation water tank, and the gas inlet of the main gas collecting pipe is higher than the liquid level of the feed liquid in the second-stage evaporation water tank and close to the top of the second-stage evaporation water tank. The water inlet of the overflow pipe arranged in the second-stage evaporation water tank is positioned at the bottom of the second-stage evaporation water tank, and the water outlet of the overflow pipe is positioned in the third-stage evaporation water tank and is higher than the water outlet of the third-stage evaporation water tank. The second stage further evaporates and concentrates by using the high temperature of the feed liquid entering from the first stage, the hot air converted from the vapor and micro-bubbles generated in the process of evaporating and concentrating the feed liquid in the second stage is sent to the third heat exchanger in the fourth stage through the main gas collecting pipe on the second stage, and the heated feed liquid in the second stage enters the third evaporation water tank through the overflow pipe.
Specifically, the main gas collecting pipes in the third stage, the fifth stage and the sixth stage penetrate through the bottom of the evaporation water tank of the stage and extend into the evaporation water tank of the stage, and the gas inlets of the main gas collecting pipes are higher than the liquid level of the feed liquid in the evaporation water tank of the stage and close to the top of the evaporation water tank of the stage; the main gas collecting pipes of the fourth stage, the seventh stage, the eighth stage and the ninth stage are arranged at the top of the evaporation water tank of the stage. Overflow pipes in the third stage and the sixth stage extend into the evaporation water tank from the bottom of the evaporation water tank, and the liquid level of the liquid in the third stage and the sixth stage is higher than that of the liquid in the first stage; the water inlets of the overflow pipes in the fourth stage, the fifth stage, the seventh stage and the eighth stage are positioned at the bottom of the evaporation water tank of the stage, and the water outlets of the overflow pipes are positioned in the evaporation water tanks of the lower stages and are higher than the water outlets of the evaporation water tanks of the lower stages. And the third heat exchangers in the third stage, the fourth stage, the fifth stage, the sixth stage, the seventh stage, the eighth stage and the ninth stage are respectively connected with the main gas collecting pipes in the first stage, the second stage, the third stage, the fourth stage, the fifth stage, the sixth stage and the seventh stage. The water collecting pipes of the eighth stage and the ninth stage are provided with a second auxiliary gas collecting pipe 7 communicated with the main gas collecting pipe of the evaporation water tank at the same stage before being converged into the water producing pipe, the second auxiliary gas collecting pipe is communicated with the main gas collecting pipe of the stage, and the main gas collecting pipes of the eighth stage and the ninth stage are combined and arranged and are simultaneously connected with the second heat exchanger. In addition, the bottom of the ninth-stage evaporation water tank is also provided with a first outlet, and a collecting tank 19 for collecting crystallized salt is arranged at the position corresponding to the first outlet.
Feed liquid in the third stage, the fourth stage, the fifth stage, the sixth stage, the seventh stage, the eighth stage and the ninth stage respectively exchanges heat with hot air converted from water vapor and micro-bubbles discharged from a main gas collecting pipe in the first stage, the second stage, the third stage, the fourth stage, the fifth stage, the sixth stage and the seventh stage in a third heat exchanger of the third stage, heat generated by phase change of the water vapor converted into condensed water in the third heat exchanger serves as a main heating heat source, heat released by temperature reduction of the hot air serves as an auxiliary heating heat source, the generated condensed water is gathered in a water producing pipe through a water collecting pipe, and uncondensed water vapor and the hot air are gathered in the main gas collecting pipe arranged at the third stage through a first auxiliary gas collecting pipe. The hot air converted from vapor and micro-bubbles generated during the evaporation concentration of the feed liquid in the third, fourth, fifth, sixth and seventh stages is discharged through the main gas collecting pipe in the stage and sent into the third heat exchanger in the fifth, sixth, seventh, eighth and ninth stages, and the feed liquid flows into the ninth stage evaporation water tank from the third stage evaporation water tank through the overflow pipe in sequence.
Specifically, all the aeration membrane modules and the third heat exchanger in the system are the same device, and in order to enable the aeration membrane modules immersed in the feed liquid to generate micro bubbles in the feed liquid after air is introduced, the aeration membrane modules are made of hydrophobic hollow fiber membranes, preferably polypropylene hydrophobic hollow fiber membranes or polytetrafluoroethylene hydrophobic hollow fiber membranes, but the invention is not limited to the above two materials, and can be replaced according to actual conditions.
Specifically, a second outlet 17 for discharging air and uncondensed water vapor, a third outlet 18 for discharging condensed water as produced water, and a first feed port 15 for feeding a raw material liquid are provided on the first heat exchanger. The second heat exchanger is provided with a mixed gas pipe 20 connected with the first heat exchanger, raw material liquid enters the first heat exchanger through a first feed inlet, and exchanges heat with condensed water with energy from a water production pipe, uncondensed water vapor from the mixed gas pipe and air in the first heat exchanger to preheat the raw material liquid for the first time. The second heat exchanger is connected with the main gas collecting pipes in the eighth stage and the ninth stage, and the raw material liquid exchanges heat with water vapor and hot air from the main gas collecting pipes in the second heat exchanger to preheat the raw material liquid for the second time.
The specific implementation method of the embodiment is as follows:
s1: preheating the raw material liquid, wherein the raw material liquid exchanges heat with condensate water which is generated in the third heat exchanger and has energy, and uncooled vapor and air in the second heat exchanger in the first heat exchanger, and the raw material liquid is subjected to first preheating; and the raw material liquid after primary preheating enters a second heat exchanger, and exchanges heat with steam and air generated by evaporative concentration of an eighth-stage evaporation water tank and a ninth-stage evaporation water tank and uncooled steam and air in a third heat exchanger in the eighth stage and the ninth stage in the second heat exchanger to carry out secondary preheating on the raw material liquid.
S2: nine-stage evaporation and concentration
When the preheated raw material liquid enters a first-stage evaporation water tank, starting a heating device arranged in the first-stage evaporation water tank to heat the raw material liquid, and setting the heating temperature at 80-100 ℃; from the third stage to the ninth stage, the water vapor generated in the evaporation concentration process in the previous stage is used as a main heating source, and the hot air converted by the micro-bubbles generated in the previous stage and the uncooled water vapor and hot air in the third heat exchanger in the previous stage are used as auxiliary heating sources; the feed liquid flows into the ninth-stage evaporation water tank from the first-stage evaporation water tank in sequence through the overflow pipe, and evaporation concentration is carried out in each stage of evaporation water tank to form nine-stage evaporation concentration.
S3: generating micro-bubbles
When the temperature of the system is stable after the heating in the step S2 is carried out for a period of time, air is introduced into the aeration membrane component through the air pipe, and the flowing water of the air is controlled by adjusting the valve of the air compressor and the valve of the pneumatic valuator, so that the aeration intensity is controlled, the air passes through the aeration membrane component to generate micro-bubbles in the feed liquid of each stage, the liquid to be evaporated is heated more uniformly, and the fluidity between water molecules and water vapor molecules of a phase interface is increased, so that the evaporation efficiency of the equipment is improved.
S4: discharging crystallized salt, condensed water, water vapor and air
The feed liquid is saturated and crystallized salt is separated out in the ninth-stage evaporation water tank after being subjected to nine-stage evaporation concentration, the separated crystallized salt is discharged from a first outlet arranged on the ninth-stage evaporation water tank and enters a collecting tank, condensed water which is formed by condensation phase change of water vapor generated in each stage of evaporation concentration in the third heat exchanger, the second heat exchanger and the first heat exchanger is discharged from a third outlet arranged on the first heat exchanger as produced water, and uncondensed water vapor and air are discharged from a second outlet arranged on the first heat exchanger.
Based on the system, the invention carries out a small experiment, and when the number n of the evaporation water tanks is set to be 7, a treatment system for 7-level evaporation concentration is formed, specifically, firstly, 13L of raw material liquid with the conductivity of 66900 mus/cm and the Total Dissolved Solids (TDS) value of 56740mg/L is added into the first-level evaporation water tank, 42L of raw material liquid is also added in the whole evaporation concentration process, the raw material liquid is preheated before being added into the first-level evaporation water tank, the heating temperature of the first-level feed liquid is set to be 90 ℃, and the first-level feed liquid is heated to be 90 ℃. Then, air is introduced into the aeration membrane component, the air flow is 105L/h, the pressure on the detection membrane side is 0.012MPa by adjusting an air compressor valve and a pneumatic valuator valve, the gas-liquid separation distance is controlled to be 21cm, the membrane area is 3.01 multiplied by 10 < -2 > m2, and the aeration intensity of the aeration membrane component is 1Nm3/(m2 & h). Under the action of water vapor and hot air, the temperature of the whole set of equipment can reach stable after 2 hours, at the moment, the temperature of the material liquid in the second-stage evaporation water tank reaches 85 ℃, the temperature of the material liquid in the third-stage evaporation water tank reaches 80 ℃, the temperature of the material liquid in the fourth-stage evaporation water tank reaches 75 ℃, the temperature of the material liquid in the fifth-stage evaporation water tank reaches 70 ℃, the temperature of the material liquid in the sixth-stage evaporation water tank reaches 65 ℃, and the temperature of the material liquid in the seventh-stage evaporation water tank reaches 60 ℃. The initial evaporation efficiency of membrane aeration is 2000g/h, and the electric conductivity of produced water is 308 mu s/cm; the TDS value detected when the concentration time is 30h is 347460mg/L, the membrane aeration evaporation efficiency is 1700g/h, and the water production conductance is 313 mu s/cm, which is because the evaporation efficiency is reduced due to the fact that the steam partial pressure of water is reduced along with the increase of the concentration multiple. The TDS value detected in 35h is 347590mg/L, the original water salt components are complex, so whether the mother liquor reaches a supersaturated state or not is roughly judged through the TDS value, the mother liquor is observed to be stopped for 1min, the liquid surface is immediately crystallized to form salt, the feed liquid in the seventh stage is saturated, the precipitated crystal salt is discharged, and the separated concentrated feed liquid is used as the feed liquid to carry out the next evaporation concentration.
Based on the system and the small trial experiment, the invention also carries out field experiments in inner Mongolia and Chongqing, and the field experiments comprise the following steps:
example 1:
and (3) treating the fracturing flow-back fluid of a certain well site in Nemontage Ordos, wherein 9 evaporation water tanks in the adopted evaporation concentration system form a 9-level evaporation concentration system. Firstly, removing fine particles such as suspended matters in a raw material liquid by flocculating and settling treatment on a flow-back liquid to obtain a raw material liquid, pumping the raw material liquid into a first-stage evaporation water tank in a 9-stage evaporation concentration system through a raw material liquid pump, setting the heating temperature, starting a membrane aeration fan to introduce air into an aeration membrane component through an air pipe for evaporation treatment after temperature gradients of various stages are formed (the temperature of the first stage is 90 ℃, and then is sequentially 85 ℃, 80 ℃, 75 ℃, 70 ℃, 65 ℃, 60 ℃, 55 ℃ and 50 ℃), discharging condensed water generated by phase change of water vapor in the evaporation process in a heat exchanger as product water into a product water tank, and discharging solid crystal salt saturated and separated out from the material liquid in a ninth-stage evaporation water tank after 40 hours from a first outlet arranged at the bottom of the ninth-stage evaporation water tank. The salt content of the produced water which is condensed water obtained after membrane aeration evaporation treatment is reduced from 79800mg/L to 350mg/L, and the COD of the produced water which is condensed water is reduced from 4608mg/L to 62mg/L, which meets the first-level standard of Integrated wastewater discharge Standard.
Example 2:
fracturing flow-back fluid of a certain shale gas drilling platform in Chongqing Dazhu is treated, and 6 evaporation water tanks in the evaporation concentration system adopted at the moment form a 6-level evaporation concentration system. Firstly, removing suspended matters in a raw material liquid through flocculation and sedimentation treatment of a flowback liquid, pumping the raw material liquid into a first-stage evaporation water tank in a 6-stage evaporation and concentration system through a raw material liquid pump, setting the heating temperature, starting a membrane aeration fan to introduce air into an aeration membrane component through an air pipe for evaporation treatment after the temperature gradients of all stages are formed (the temperature of the first stage is 90 ℃, and then is 85 ℃, 80 ℃, 75 ℃, 70 ℃ and 65 ℃), discharging condensed water generated by phase change of water vapor in a heat exchanger in the evaporation process as product water into a product water tank, and discharging solid crystal salt which is separated out after the material liquid is subjected to evaporation and concentration in a sixth-stage evaporation water tank after 33h from a first outlet arranged at the bottom of the sixth-stage evaporation water tank. The salt content of the produced water which is condensed water obtained after membrane aeration evaporation treatment is reduced from 120600mg/L to 480mg/L, and the COD of the produced water which is condensed water is reduced from 3977mg/L to 19mg/L, which meets the discharge standard of the water pollutants in Minjiang and Tuo river basin of Sichuan province DB 51/2311-2016.
Claims (8)
1. The method for treating the wastewater with high salt content is characterized in that the raw material liquid generates condensed water after n-level continuous evaporation concentration, the material liquid is saturated in the nth level to separate out crystal salt, the first level evaporation concentration utilizes a heater to heat the material liquid to 80-100 ℃, the second level evaporation concentration utilizes the high temperature of the entered material liquid to further carry out evaporation concentration, the mth level evaporation concentration utilizes the heat generated by the phase change of the water vapor generated in the evaporation concentration process of the (m-2) level as a heat source for main heating, the material liquid after evaporation concentration flows into the (m-1) level from the (m-2) level, the condensed water generated by the phase change of the water vapor in the evaporation concentration process from the third level to the nth level is removed as produced water, and the water vapor generated in the evaporation concentration processes of the (n-1) level and the nth level are removed, m is more than or equal to 3 and less than or equal to n.
2. The method for treating the wastewater with high salt content according to claim 1, wherein n in the n stages of continuous evaporation and concentration is 6-20.
3. The method for treating wastewater containing high salt content according to claim 1, wherein the evaporation concentration process further adopts an aeration mode to generate micro-bubbles in the feed liquid of each stage of evaporation concentration, so that the feed liquid is heated more uniformly and the fluidity between water molecules and water vapor molecules at the phase interface is increased, thereby improving the evaporation efficiency of the equipment.
4. The method for treating the wastewater with high salt content according to claim 3, wherein the air flow is 95-125L/h.
5. The method for treating wastewater with high salt content according to claim 4, wherein a temperature gradient is formed when the evaporation concentration of the n stages is stable.
6. The method for treating wastewater with high salt content according to claim 1, characterized in that the raw material liquid is subjected to heat exchange with condensed water which is generated in the evaporation concentration process from the third stage to the nth stage and carries energy, so as to realize primary preheating of the raw material liquid; the first preheated raw material liquid and the hot air converted from the steam and the bubbles generated in the evaporation concentration process of the (n-1) th stage and the nth stage are heated to realize the second preheating of the raw material liquid.
7. The method for treating the wastewater with high salt content according to any one of claims 1 to 6, wherein the n-stage continuous evaporative concentration is realized by an n-stage evaporative concentration system, the n-stage evaporative concentration system comprises n evaporative water tanks (1), a heater (2), an overflow pipe (4), a main gas collecting pipe (5), a water producing pipe (9), a second feeding hole (14) and a raw material liquid pipe (21), the evaporative water tanks (1) are sequentially connected in series to form the n-stage evaporative system, the overflow pipe (4) is arranged in each stage of evaporative water tank (1) and is used for feeding the liquid into the next stage of evaporative water tank, the main gas collecting pipe (5) is arranged on each stage of evaporative water tank (1) and is used for discharging the water vapor generated in the stage, the heater (2) is arranged in the first stage evaporative water tank (1), the second feeding hole (14) is arranged on the first stage evaporative water tank (1), the raw material liquid pipe (21) is communicated with the second feeding hole (14), the third heat exchanger (10) is arranged in the evaporation water tank (1) from the third stage to the nth stage and is used for receiving water vapor discharged from the main gas collecting pipe (5) in the previous stage, the water production pipe (9) is used for receiving condensed water generated in the third heat exchanger (10), wherein the heat generated by the phase change of the water vapor discharged from the m-2 stage main gas collecting pipe in the mth stage third heat exchanger is used as a heat source for the main heating of the m-stage feed liquid, the uncondensed water vapor in the third heat exchanger is converged into the current stage main gas collecting pipe, and the water vapor and air generated in the n-1 stage and the n stage are discharged through the same stage main gas collecting pipe.
8. The method for treating wastewater containing high salt content according to claim 7, further comprising an aeration device (3) for generating micro bubbles in the feed liquid in each stage, wherein the aeration device (3) comprises an aeration membrane module (22) arranged in the evaporation water tank of each stage, and an air pipe (13) connected with the aeration membrane module (22) and used for providing air for the aeration membrane module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911283864.8A CN110921744A (en) | 2019-12-13 | 2019-12-13 | High-salt-content wastewater treatment method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911283864.8A CN110921744A (en) | 2019-12-13 | 2019-12-13 | High-salt-content wastewater treatment method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110921744A true CN110921744A (en) | 2020-03-27 |
Family
ID=69859841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911283864.8A Pending CN110921744A (en) | 2019-12-13 | 2019-12-13 | High-salt-content wastewater treatment method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110921744A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111785399A (en) * | 2020-07-06 | 2020-10-16 | 武汉第二船舶设计研究所(中国船舶重工集团公司第七一九研究所) | System for heat export of marine nuclear power platform |
| WO2020252552A1 (en) * | 2019-06-19 | 2020-12-24 | Formitex Da Bahia Indústria E Comércio S.A. | Method and system for recovering waste washing water effluent generated in the production method for hydroxypropyl methylcellulose (hpmc) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4132588A (en) * | 1976-02-06 | 1979-01-02 | Asahi Kasei Kogyo Kabushiki Kaisha | Concentration process by multistage, multiple effect evaporator |
| US6833056B1 (en) * | 1997-12-25 | 2004-12-21 | Ebara Corporation | Desalination method and desalination apparatus |
| CN100582022C (en) * | 2003-04-11 | 2010-01-20 | 北京环能海臣科技有限公司 | Solar thermosiphon circulating evaporator surface film multieffective distillation desalination equipment |
| CN101874985A (en) * | 2009-04-28 | 2010-11-03 | 吕晓龙 | Film evaporation concentrating method and device |
| CN103316588A (en) * | 2012-03-20 | 2013-09-25 | 天津工业大学 | Multiple-effect membrane distillation device and method |
| CN104190258A (en) * | 2014-09-18 | 2014-12-10 | 天津工业大学 | Fluid-gap multi-effect membrane distillation process and device |
-
2019
- 2019-12-13 CN CN201911283864.8A patent/CN110921744A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4132588A (en) * | 1976-02-06 | 1979-01-02 | Asahi Kasei Kogyo Kabushiki Kaisha | Concentration process by multistage, multiple effect evaporator |
| US6833056B1 (en) * | 1997-12-25 | 2004-12-21 | Ebara Corporation | Desalination method and desalination apparatus |
| CN100582022C (en) * | 2003-04-11 | 2010-01-20 | 北京环能海臣科技有限公司 | Solar thermosiphon circulating evaporator surface film multieffective distillation desalination equipment |
| CN101874985A (en) * | 2009-04-28 | 2010-11-03 | 吕晓龙 | Film evaporation concentrating method and device |
| CN103316588A (en) * | 2012-03-20 | 2013-09-25 | 天津工业大学 | Multiple-effect membrane distillation device and method |
| CN104190258A (en) * | 2014-09-18 | 2014-12-10 | 天津工业大学 | Fluid-gap multi-effect membrane distillation process and device |
Non-Patent Citations (1)
| Title |
|---|
| 张优慰等: "膜曝气促进结晶工艺探究", 《膜科学与技术》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020252552A1 (en) * | 2019-06-19 | 2020-12-24 | Formitex Da Bahia Indústria E Comércio S.A. | Method and system for recovering waste washing water effluent generated in the production method for hydroxypropyl methylcellulose (hpmc) |
| CN111785399A (en) * | 2020-07-06 | 2020-10-16 | 武汉第二船舶设计研究所(中国船舶重工集团公司第七一九研究所) | System for heat export of marine nuclear power platform |
| CN111785399B (en) * | 2020-07-06 | 2023-06-20 | 武汉第二船舶设计研究所(中国船舶重工集团公司第七一九研究所) | System for be used for ocean nuclear power platform heat to derive |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108793571B (en) | Enhanced desalination high-salinity wastewater treatment system | |
| CN105502540B (en) | A kind of good antiscale property and the desulfurization wastewater multiple-effect evaporation condensing crystallizing processing method of corrosion | |
| CN104926011B (en) | The evaporative crystallization zero-discharge treatment system and processing method of a kind of high-COD waste water | |
| KR101769949B1 (en) | Evaporation and concentration system and method having improved energy efficiency | |
| CN211847557U (en) | High salt wastewater treatment system that contains | |
| CN110921744A (en) | High-salt-content wastewater treatment method | |
| CN204569599U (en) | A kind of novel no pollution sewage effluent total system | |
| CN111704301A (en) | Landfill leachate treatment process based on PMVR-ZLD | |
| CN112010380B (en) | Preparation device and preparation method of hot purified water | |
| CN102139983A (en) | Waste water treatment method and system | |
| CN111453800A (en) | Membrane distillation system and method for urine resource recovery | |
| WO2022057052A1 (en) | Treatment system and treatment method for landfill leachate wastewater | |
| CN203295308U (en) | Organic salt-containing waste water treating system | |
| CN111072211A (en) | Method and system for circulating salt separation crystallization | |
| CN105110396B (en) | Method and device for continuously separating low-boiling point substances in wastewater produced by extraction of natural gas and shale gas | |
| CN113307433A (en) | Four-effect cross-flow pharmaceutical wastewater evaporative crystallization system with external heat exchanger | |
| CN210764425U (en) | Solar high-temperature high-pressure expansion flash system for salt-containing wastewater | |
| CN205347092U (en) | Desulfurization waste water zero release processing system | |
| CN110921745A (en) | High salt wastewater treatment system that contains | |
| CN109133465A (en) | A kind of Waste Heat Reuse vacuum membrane distillation zero discharge treatment device and method | |
| CN115028235A (en) | Low temperature heat pump membrane distillation waste water concentration system | |
| CN212246687U (en) | Landfill leachate treatment system | |
| WO2022120926A1 (en) | Raw water heating and hard water removal treatment apparatus | |
| CN212246688U (en) | Advanced treatment system for landfill leachate | |
| CN101920123A (en) | Internal circulation evaporator with settling chamber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200327 |