Ion replacement concentration membrane stack off-line cleaning regeneration deviceTechnical Field
The invention relates to a water treatment technology, belongs to the technical field of water treatment, and particularly relates to an ion replacement concentration membrane stack offline cleaning and regenerating device.
Background
The current zero discharge of desulfurization wastewater in a power plant is an inevitable trend of environmental protection, and an ion replacement concentration (Ions Replace Concentration Technology, abbreviated as IRCT) technology is successfully applied to the zero discharge engineering of desulfurization wastewater in the power plant, so that the technology fills the blank of the technology of softening-free desalination of desulfurization slurry and recycling of concentrated solution in China, and the successful application of the technology inevitably brings wastewater treatment into a brand-new era.
The Ion Replacement Concentration (IRCT) technology can be widely applied to desalination and concentration reduction treatment of high-salt-content and high-hardness wastewater in various industrial fields such as electric power, coal mine, coal chemical industry, petrochemical industry, metallurgy and the like, and the high-hardness wastewater does not need softening, and has high concentration ratio and low investment and operation cost. Ion Replacement Concentration (IRCT) membrane stacks are used as core components of Ion Replacement Concentration (IRCT) technology to carry out ion replacement desalination and concentration reduction in the process of treating high-salt-content and high-hardness wastewater, and because the complex ion components in the wastewater can form pollutants on the surface of the membrane to prevent ion replacement from affecting desalination efficiency, the Ion Replacement Concentration (IRCT) membrane stacks need to be removed, maintained, cleaned and regenerated regularly.
At present, in the water treatment industry, chemical cleaning methods are generally aimed at ultrafiltration, reverse osmosis pollution and continuous electrodeionization, demineralized water or purified water equipment is produced, the first edition methods are provided by membrane manufacturers, the medicament manufacturers develop novel medicaments, the manufacturers and multiple parties are combined, and a more effective cleaning scheme is tested. However, the desalted water or the purified water belongs to the back-end equipment, and the desalted water or the purified water is used as the production target, so that the water quality at the stage is stable. The wastewater is generated according to actual production activities, the water quality fluctuation is large, the types are multiple, the Ion Replacement Concentration (IRCT) is developed by treating desulfurization wastewater of a coal-fired power plant, the water quality fluctuation of the desulfurization wastewater is related to coal, limestone used for desulfurization, water quality of water replenishing of a desulfurization system, combustion condition of a unit and working condition of front-end electric dust removal, the treated wastewater is high-salt-content and high-hardness wastewater, the treated wastewater contains a large amount of calcium and magnesium ions, and scaling is very easy to occur in an alkaline environment. Ion Replacement Concentration (IRCT) technology realizes the concentration reduction of desulfurization wastewater, the TDS of concentrated solution salt can reach more than 14%, crystallization is easy to separate out, and a cleaning device suitable for the Ion Replacement Concentration (IRCT) technology is required to be developed according to the water quality change and the equipment specificity.
The Ion Replacement Concentration (IRCT) membrane stack is used as a core component, and frequent disassembly and assembly not only increase the on-site overhaul workload, but also influence the integral desalination rate, one membrane stack is a unit value, one group of membrane stacks is 16 units, and inlet and outlet pipes of the membrane stack are connected by a main pipe. The membrane stacks need to be regularly maintained, cleaned and regenerated in use, and the membrane stack system can be considered to be provided with an online cleaning system, but the online cleaning system has the defects that inlet and outlet pipes of a membrane stack unit are all in a mother pipe, if one membrane stack has performance problems and needs to be cleaned, all membrane stacks need to be reorganized and shut down, so that the overall desalination efficiency is reduced; the disassembly and cleaning process is tedious, a large amount of manpower is consumed, the working efficiency is low, potential safety hazards exist, and the personnel are easy to crush and crush.
Disclosure of Invention
In order to solve the problems, the invention discloses an ion replacement concentrated membrane stack offline cleaning and regenerating device and a cleaning method thereof, wherein the cleaning device can move to clean the membrane stacks one by one without affecting the normal operation of other membrane stacks, the membrane stacks can be cleaned without being disassembled, the labor force is reduced, the overall cleaning time is shortened, and the working efficiency is improved. The method is based on 206-day pilot scale of the research and development process of the Ion Replacement Concentration (IRCT) technology, and various cleaning schemes are adopted in 14-month demonstration engineering operation, and finally a safe and reliable cleaning scheme is summarized.
An ion replacement concentrated membrane stack offline cleaning and regenerating device comprises a movable frame, wherein a membrane cleaning water tank, a cleaning water pump, a security filter and a control box are arranged on the movable frame, a water inlet main pipe is arranged at a water inlet of the membrane cleaning water tank, a water outlet main pipe is connected at a water outlet of the membrane cleaning water tank, a medicament stirring machine is not required to be arranged according to cleaning medicament and characteristics of the membrane cleaning water tank, a small amount of heat is generated in a cleaning process, and an electric heating device is not required to be arranged; the water outlet end of the ion exchange concentration membrane stack is connected with the water inlet main pipe of the membrane cleaning water tank through six parallel water outlet branch pipes; the water outlet main pipe of the water outlet end of the membrane cleaning water tank is sequentially connected with a cleaning water pump and a security filter and is finally connected with the water inlet end of the ion exchange concentration membrane stack through six parallel water outlet branch pipes.
Further, each water inlet branch pipe and each water outlet branch pipe are in butt joint with the water outlet and the water inlet of the ion exchange concentration membrane stack through hoses.
Further, the bottom of the movable frame is provided with 4 universal wheels, wherein two wheels are provided with locking devices, so that the sub-replacement concentration membrane stacks of each unit can be conveniently moved and butted.
Further, a manual valve and a glass rotameter are respectively arranged on the 6 branch pipes of the primary pipe of the outlet of the cartridge filter.
Furthermore, a sampling port is respectively arranged on the main pipe for cleaning water inlet and water outlet, so that the sampling and measurement can be conveniently performed at any time during cleaning.
Further, the external connectors of the six water inlet branch pipes are external threads, and the external connectors of the six water outlet branch pipes are internal threads.
Further, a reflux valve is arranged between the outlet of the cleaning water pump and the inlet of the cartridge filter; the other end of the reflux valve is connected with the cleaning water tank through a reflux pipe. The cleaning water pump adopts frequency conversion as a substitute of the scheme, the frequency conversion can be set to slowly increase the frequency, so that the impact on the membrane is reduced, but when the membrane is blocked by dirt, the pressure is greatly increased, and the membrane is possibly damaged in an irreparable way, so that the flow and the pressure are optimally adjusted in a reflux way.
The cleaning method of the ion exchange concentrated membrane stack cleaning and regenerating device comprises the following steps:
step 1: checking the cleaning device equipment;
Step 2: checking that the membrane stack is out of operation; after the membrane stack is shut down and power is off, the front cover plate and the rear cover plate of the membrane stack are opened, and the lower part work can be performed after no voltage is confirmed by experience electricity. Sequentially closing the manual valves (6 groups) at the inlet of the membrane stack, and sequentially closing the manual valves (6 groups) at the outlet of the membrane stack;
Step 3: flushing before membrane stacking;
step 4: preparing a membrane stack cleaning medicament and cleaning and regenerating;
step 5: flushing after membrane stacking;
Step 6: and (5) putting the membrane stack into operation after cleaning.
Further, the step 1: the off-line cleaning device is pushed to the vicinity of a membrane stack to be cleaned, and 200L of industrial water is injected into a membrane cleaning water tank; opening inlet and outlet valves of the cleaning water pump, and powering on the control box to start the cleaning water pump, so that the cleaning water pump can be ensured to normally operate; and checking whether six hoses of the outlet and the reflux port of the cleaning device are installed correctly or not (one side of the outlet hose is connected with the outlet of the cleaning device by one side of DN20 loose joint internal thread, and one side of the reflux port hose is connected with the reflux port of the cleaning device by one side of DN20 loose joint external thread).
Further, the step 3 specifically includes
Step 3.1pH adjustment: the loose joint of the membrane stack inlet regulating valve and the corrugated pipe is disassembled, 6 paths are totally provided, the membrane stack inlet is formed, and the flexible pipe is reserved on the membrane stack and is externally opened at the front lower part of the membrane stack; and disassembling the loose joint of the membrane stack outlet (the membrane stack outlet pipe, the upper part of the back surface of the membrane stack and the middle channel of the membrane stack) and the corrugated pipe, and observing that the water flowing out of the corrugated pipe at the inlet of the membrane stack is normal. The loose joint on the outlet hose of the cleaning device is connected with the loose joint of the outlet of the membrane stack body (6 paths, adopting a back flushing principle) and is marked in one-to-one correspondence, a six-path outlet valve of the cleaning device is opened to start a cleaning water pump to flush the membrane stack forwards, the pressure of an outlet pressure gauge of a security filter of the cleaning device is observed and adjusted to be 0.08MPa, the flow rate of the 6 paths of outlet pipes is about 2500L/h, and a large amount of water flows out from an inlet of the original membrane stack and enters a floor drain; when the washing of 200L industrial water in the membrane cleaning water tank is finished, the washing can be stopped when the PH value of water flowing out of the membrane stack is detected to be about 7, and if the PH value shows that the washing of industrial water is continuously repeated after the washing;
Step 3.2: the pH was finally confirmed. When the PH value of water flowing out of the membrane stack is neutral, the loose joint on the reflux hose of the cleaning device is connected with the loose joint on the corrugated pipe at the inlet of the membrane stack, 200L of industrial water is injected into the cleaning water tank to start the cleaning water pump, at the moment, the industrial water is not required to be closed, the industrial water is continuously injected into the membrane cleaning water tank (excessive water flows out of the overflow pipeline of the membrane cleaning water tank), and the pressure and the flow rate are observed and regulated (the pressure of the outlet pressure gauge of the security filter of the cleaning device is regulated to be 0.08MPa, and the flow rate of the outlet pipe of 6 paths is about 2500L/h). After 30 minutes of operation, the pH was measured at the safety filter sampling port. If the PH value is still about 7, the cleaning water pump is stopped, and the water in the membrane cleaning water tank is emptied; if the PH value is acidic, the membrane cleaning water tank is emptied and injected with industrial water to continuously start the cleaning water pump for circulating flushing, and the steps are repeated until the PH value is qualified.
Further, 100L of industrial water is injected into the membrane cleaning water tank, 12L of 30% concentration sodium hydroxide solution is added, the concentration of sodium hydroxide in the membrane cleaning water tank is required to be 3%, and the industrial water is continuously added until the liquid level reaches 120L; and closing valves of the cleaning device, which are connected with the outlets of the cathode and anode channels of the membrane stack and the return pipeline, starting a cleaning water pump to circularly clean, and observing and adjusting pressure and flow. The circulation is carried out for 30 minutes, the shutdown is carried out for 5 minutes for one period, and the soaking effect is optimal after 4-5 periods of cleaning for 12 hours.
Further, the step 5 specifically includes:
Step 5.1: removing alkali liquor; after the membrane stack cleaning liquid is soaked, a cleaning water pump is started, and the pressure and the flow are observed and adjusted. Industrial water is injected into the membrane cleaning water tank while the cleaning water pump is started to circulate, the diluted membrane cleaning water tank solution overflows and is discharged, and after the circulation is performed for 10 minutes, the membrane cleaning water tank is emptied.
Step 5.2: adjusting the PH; and (3) injecting industrial water to flush the membrane stack after the solution in the membrane cleaning water tank is emptied, repeating the emptying replacement, and flushing after the pH value of the cleaning water is about 7.
Step 5.3: final PH confirmation; when the PH value of water flowing out of the membrane stack is neutral, the membrane cleaning water tank is filled with 200L of industrial water to start the cleaning water pump, at the moment, the industrial water is not needed to be closed, the membrane cleaning water tank is continuously filled with the industrial water, and the redundant water flows out of the overflow pipeline and is observed to adjust the pressure and flow; after 30 minutes of operation, the PH value is measured at a sampling port of the security filter; if the PH value is still about 7, the cleaning water pump is stopped, and the water in the membrane cleaning water tank is emptied; if the PH value is alkaline, the membrane cleaning water tank is emptied and injected with industrial water, the cleaning water pump is continuously started to circularly wash, and the steps are repeated until the PH value is qualified.
Further, the step 6: after the post-flushing is finished, the membrane cleaning water tank is emptied, the power supply is closed, and a pipeline connected with the cleaning device and the membrane stack is removed; the membrane pile outlet pipeline is restored first, the membrane pile outlet valve is opened, and the membrane pile is flushed for 2 minutes by water in the circulation pipeline of each flow channel. Closing a membrane stack outlet valve, installing a membrane stack inlet pipeline, opening a membrane stack outlet manual valve, and then opening a membrane stack inlet manual valve, wherein the membrane stack can be normally operated after 1 hour of voltage circulation without applying voltage. And (5) cleaning and regenerating the membrane stack.
Furthermore, when the membrane is lightly polluted or maintainably cleaned, a plurality of groups of cleaning can be adopted, the step 3 can be completed simultaneously, the step 4 can be carried out synchronously, each group of the step 4 is reduced, whether the cleaning agent is replaced or not is determined according to the cleaning condition, if the agent is not required to be replaced, a small amount of agent is required to be added, the cleaning effect is ensured, and finally, the step 5 is synchronously completed and put into operation together. To ensure the cleaning effect, at most 4 groups were cleaned at a time within 12 hours.
The invention has the beneficial effects that:
1. The offline cleaning and regenerating device saves a great amount of manpower for disassembling the membrane stack, and reduces the maintenance workload;
2. The device replaces the process of disassembling and cleaning the membrane stack, shortens the time of incapability of running due to overhauling and maintaining equipment, and improves the integral desalination rate of the system;
3. the device can clean and regenerate six paths of flow channels in the membrane stack in a targeted manner, can be used for pickling and alkaline cleaning, and is flexible to operate;
4. the device is movable, the membrane stack is cleaned on the membrane frame in an off-line manner, the branch pipes of the cleaning device are provided with the flow meter and the pressure meter in one-to-one correspondence with the flow channels of the membrane stack, operators can observe and adjust the flow and the pressure of the pipeline at any time, and the device can diagnose whether the inside of the membrane stack leaks or not and can be used as detection equipment of the membrane stack.
5. The device can carry out deep cleaning and maintenance cleaning on the membrane stack, and when in maintenance cleaning, the cleaning work of at most 8 groups can be completed in a single day, and the cleaning work of 1 set of 16 groups of membranes can be completed in two days.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2, a flow chart of the present invention;
FIG. 3 is a schematic view of a moving frame according to the present utility model
List of reference numerals:
a membrane cleaning water tank 2, a cleaning water pump 3, a cartridge filter 4, a pressure gauge 5, a manual regulating valve 6, a glass rotameter, a 7-moving frame and an 8-control box.
Detailed Description
The present invention is further illustrated in the following drawings and detailed description, which are to be understood as being merely illustrative of the invention and not limiting the scope of the invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings, and the words "inner" and "outer" refer to directions toward or away from, respectively, the geometric center of a particular component.
As shown in fig. 1 and 2, an ion replacement concentrated membrane stack offline cleaning and regenerating device comprises a movable frame 7, wherein a membrane cleaning water tank 1, a cleaning water pump 2, a cartridge filter 3 and a control box 8 are arranged on the movable frame 7, a water inlet of the membrane cleaning water tank 1 is provided with a water inlet pipe, and a water outlet of the membrane cleaning water tank is connected with a water outlet pipe; the water outlet end of the ion exchange concentration membrane stack is connected with the water inlet main pipe of the membrane cleaning water tank through six parallel water outlet branch pipes; the water outlet mother pipe at the water outlet end of the membrane cleaning water tank 1 is sequentially connected with a cleaning water 2 pump and a security filter 3 and finally connected with the water inlet end of the ion exchange concentration membrane stack through six parallel water outlet branch pipes.
The 6 paths of parallel water outlet branch pipes are connected in parallel, the tail ends of UPVC pipelines of the water inlet and outlet DN25 branch pipes of each path are respectively provided with a ∅ hose with the length of 5 meters which is in butt joint with the water inlet and outlet of the membrane stack, and the external interfaces are UPVC loose joints of DN20 (wherein the external interfaces of six water inlet branch pipes are external threads and the external interfaces of 6 water outlet branch pipes are internal threads).
A reflux valve is arranged between the outlet of the cleaning water pump and the inlet of the cartridge filter to the membrane cleaning water tank, so that the inlet and outlet of the cartridge filter are not under overpressure (the outlet pressure of the cartridge filter is controlled to be 0.06-0.08 MPa), a manual valve and a glass rotameter 6 (the measuring range is 0-3000L/h) are respectively arranged on 6 branch pipes of a main pipe of the outlet of the cartridge filter, the flow rate is regulated by the manual valve in front of the flowmeter (the flow rate of the outlet of the 6 branch pipes is controlled to be 2500L/h), and sampling ports are respectively arranged on the main pipes of the cleaning water inlet and outlet, so that the sampling and the measurement are convenient during cleaning at any time.
The invention relates to a cleaning method of an ion replacement concentration membrane stack cleaning and regenerating device, which comprises the following steps,
Step 1: checking the cleaning device equipment. The off-line cleaning device is pushed to the vicinity of a membrane stack to be cleaned, and 200L of industrial water is injected into a membrane cleaning water tank; opening inlet and outlet valves of the cleaning water pump, and powering on the control box to start the cleaning water pump, so that the cleaning water pump can be ensured to normally operate; and checking whether six hoses of the outlet and the reflux port of the cleaning device are installed correctly or not (one side of the outlet hose is connected with the outlet of the cleaning device by one side of DN20 loose joint internal thread, and one side of the reflux port hose is connected with the reflux port of the cleaning device by one side of DN20 loose joint external thread).
Step 2: the stack was checked for out of service. After the membrane stack is shut down and power is off, the front cover plate and the rear cover plate of the membrane stack are opened, and the lower part work can be performed after no voltage is confirmed by experience electricity. The manual valves (6 groups) at the inlet of the membrane stack are closed in sequence, and the manual valves (6 groups) at the outlet of the membrane stack are closed in sequence.
Step 3: the membrane is rinsed before stacking.
The first step: and (5) pH adjustment. The loose joint (6 paths are the membrane stack inlet and are arranged at the front lower part of the membrane stack) of the membrane stack inlet regulating valve and the corrugated pipe is disassembled, and a hose is reserved on the membrane stack and is externally opened; and disassembling the loose joint of the membrane stack outlet (the membrane stack outlet pipe, the upper part of the back surface of the membrane stack and the middle channel of the membrane stack) and the corrugated pipe, and observing that the water flowing out of the corrugated pipe at the inlet of the membrane stack is normal. The loose joint on the outlet hose of the cleaning device is connected with the loose joint on the outlet of the membrane stack body (6 paths, adopting a back flushing principle) and is marked in one-to-one correspondence, a cleaning water pump is started to flush the membrane stack before the six paths of outlet valves of the cleaning device are opened, the pressure of the outlet pressure gauge of the security filter of the cleaning device is observed and adjusted to be 0.08MPa, the flow rate of the 6 paths of outlet pipes is about 2500L/h, and a large amount of water flows out from the inlet of the original membrane stack and enters the floor drain. When the washing of 200L industrial water in the membrane cleaning water tank is finished, the washing can be stopped when the PH value of the water flowing out of the membrane stack is detected to be about 7, and if the PH value shows that the washing of industrial water is continuously repeated.
And a second step of: the pH was finally confirmed. When the PH value of water flowing out of the membrane stack is neutral, the loose joint on the reflux hose of the cleaning device is connected with the loose joint on the corrugated pipe at the inlet of the membrane stack, 200L of industrial water is injected into the cleaning water tank to start the cleaning water pump, at the moment, the industrial water is not required to be closed, the industrial water is continuously injected into the membrane cleaning water tank (excessive water flows out of the overflow pipeline of the membrane cleaning water tank), and the pressure and the flow rate are observed and regulated (the pressure of the outlet pressure gauge of the security filter of the cleaning device is regulated to be 0.08MPa, and the flow rate of the outlet pipe of 6 paths is about 2500L/h). After 30 minutes of operation, the pH was measured at the safety filter sampling port. If the PH value is still about 7, the cleaning water pump is stopped, and the water in the membrane cleaning water tank is emptied; if the PH value is acidic, the membrane cleaning water tank is emptied and injected with industrial water to continuously start the cleaning water pump for circulating flushing, and the steps are repeated until the PH value is qualified.
Step 4: and (5) preparing a membrane stack cleaning agent and cleaning and regenerating. 100L of industrial water is injected into the membrane cleaning water tank, 12L of 30% sodium hydroxide solution is added, the concentration of sodium hydroxide in the membrane cleaning water tank is required to be 3%, and the industrial water is continuously added until the liquid level reaches 120L; and closing valves of the cleaning device, which are connected with outlets of the cathode and anode flow channels of the membrane stack and a return pipeline, starting a cleaning water pump to circularly clean, and observing the adjustment pressure and flow (the pressure of an outlet pressure gauge of a security filter of the cleaning device is adjusted to be 0.08MPa, and the flow of a 6-way outlet pipe is about 2500L/h). The circulation is carried out for 30 minutes, the shutdown is carried out for 5 minutes for one period, and the soaking effect is optimal after 4-5 periods of cleaning for 12 hours.
Step 5: and (5) flushing after membrane stacking.
The first step: and (5) removing alkali liquor. After the membrane stack cleaning liquid is soaked, a cleaning water pump is started, and the pressure and the flow rate are observed (the pressure of an outlet pressure gauge of a security filter of a cleaning device is regulated to be 0.08MPa, and the flow rates of 6 paths of outlet pipes are all about 2500L/h). Industrial water is injected into the membrane cleaning water tank while the cleaning water pump is started to circulate, the diluted membrane cleaning water tank solution overflows and is discharged, and after the circulation is performed for 10 minutes, the membrane cleaning water tank is emptied.
And a second step of: and (5) pH adjustment. And (3) injecting industrial water to flush the membrane stack after the solution in the membrane cleaning water tank is emptied, repeating the emptying replacement, and flushing after the pH value of the cleaning water is about 7.
And a third step of: the pH was finally confirmed. When the PH value of water flowing out of the membrane stack is neutral, the membrane cleaning water tank is filled with 200L of industrial water to start the cleaning water pump, at the moment, the industrial water is not needed to be closed, the membrane cleaning water tank is continuously filled with the industrial water, and the redundant water flows out of the overflow pipeline and is observed to adjust the pressure and flow; after 30 minutes of operation, the PH value is measured at a sampling port of the security filter; if the PH value is still about 7, the cleaning water pump is stopped, and the water in the membrane cleaning water tank is emptied; if the PH value is alkaline, the membrane cleaning water tank is emptied and injected with industrial water, the cleaning water pump is continuously started to circularly wash, and the steps are repeated until the PH value is qualified.
Step 6: and (5) putting the membrane stack into operation after cleaning. And after the post-flushing is finished, the membrane cleaning water tank is emptied, the power supply is closed, and a pipeline connected with the membrane stack by the cleaning device is removed. The membrane stack outlet pipeline is restored first, the membrane stack outlet valve is opened, and the membrane stack is flushed by water in the respective circulation pipeline of the flow channels for 2 minutes (preventing alkaline substances in the membrane stack from being deposited on the membrane surface by reaction). Closing a membrane stack outlet valve, installing a membrane stack inlet pipeline, opening a membrane stack outlet manual valve, and then opening a membrane stack inlet manual valve, wherein the membrane stack can be normally operated after 1 hour of voltage circulation without applying voltage. And (5) cleaning and regenerating the membrane stack.
The technical means disclosed by the scheme of the invention is not limited to the technical means disclosed by the embodiment, and also comprises the technical scheme formed by any combination of the technical features.