Membrane block fouling is mainly due to the following types:
o Particle/colloid fouling
o Inorganic fouling
o Organic fouling
o Microbial fouling
Cleaning method time (minutes) Remarks
Acid cleaning 30-50
Saline cleaning 35-60
Disinfection 25-40
Rinse p>Base washing 30-50
Brine washing 35-60
Disinfection 25-40
Rinsing ≥ 50
Regeneration ≥ 120 According to the system's process requirements until the effluent resistivity required indicators
Single membrane block cleaning fluid dosage
Model fluid dosage (liters) Remarks
MX-50 50 1. Acid washing temperature 15-25℃
2. Caustic washing temperature 25-30℃
3. The water used for dosage must be RO water
or deionized water higher than RO water
MX-100 80
MX-200 110
MX-300 150
. If the number of membrane blocks is greater than 1, multiply the number of membrane blocks by the number of solutions in the tableRegeneration of EDI Membrane Blocks
o Make sure that there is no chemical residue in the EDI membrane blocks.
o Construct the system as a closed-circuit self-circulating line.
o Regulate all flow rates and pressures in the normal operating mode.
o Power up the EDI and adjust the current by slowly loading the EDI in steps starting at 2A (not to exceed
a maximum of 4A).
o Until the resistivity of the produced water reaches the process requirements or ≥ 12MΩ.cm
o Tips: The regeneration of the membrane block is a relatively long time, sometimes it may be as long as 10-24 hours or even
to a longer time.
Precautions for EDI operation and maintenance
Note: Before commissioning, operation and maintenance, please read the operation and maintenance manual provided by the EDI manufacturer. This note only reminds the user to pay special attention to the commissioning, operation and maintenance, please refer to the operation and maintenance manuals provided by the EDI manufacturer for detailed operation and maintenance contents.
I. Requirements for influent water quality and necessary auxiliary equipment
(A) Requirements for influent water quality: The pre-treatment system must have a RO system, and to ensure that the RO system operates normally. lt; 0.01
6 Sulfide (S- ) ppm < 0.01
7 pH 4-11
8 Total Hardness (as CaCO3) ppm < 1.0
9 Silicon Dioxide (SiO2) ppm < 1.0
10 Total Organic Carbon (TOC) ppm <. 0.5
Remarks: 1. Conductivity calculation = Conductivity measured by Conductivity Meter + 2.66xCO2 Concentration (ppm as CO2) + 1.94xSiO2 (ppm as SiO2)
2. Pay special attention to the hardness of inlet stream and concentration of Silicon Dioxide at the beginning of the startup period to avoid exceeding 1.0 ppm.
(2) Attachments Equipment: In order to protect the module and facilitate subsequent system monitoring, it is strongly recommended that the EDI system should include at least the following ancillary equipment:
1. Stable power supply equipment: In order to maintain stable operation of the system, the power supply system should provide a stable DC power supply to the module, and the system can be operated in a constant current mode (V = IR, that is, after the setting of the current (I), the current will not be changed with the quality of the incoming stream, the quality of the incoming stream will not be changed. The change of inlet water quality only affects the resistance (R) and voltage (V)).
2. Flow switch or flow control device: In order to protect the module, when there is no water entering the module, the module power must be turned off immediately, and the flow switch must be connected to the power supply.
3. Manometer: Manometers should be installed at least at the inlet end and at the outlet end of the produced and thickened water to monitor the inlet and outlet pressures.
4. Inlet and outlet water flow meters: to facilitate the adjustment of water production rate. Can use the flow meter with a control point (can be used as a flow switch).
5. System control (PLC control): In addition to controlling the system no water into the power failure device, should also be controlled in the inflow of water into a period of time, if the power supply is still not available, the flow should be stopped (such as the pump start 30 seconds (depending on the distance from the pump to the EDI to adjust the time), if the power supply is still not available, it should be turned off the pump, and issue an alarm), in order to avoid saturation of the resin in the EDI membrane stack, affecting the quality of subsequent water production. Subsequent water quality.
Second, the trial notes:
(a) Check before the trial
1. Before the trial should check the pipeline, fittings and control system installation is complete, the inspection should be turned off before the power supply, in order to maintain the safety of personnel.
2. Module torque check: check and lock according to the operation manual section 3.2. Coupling bolt torque 1-8 25 ft.lbs. 11-14 12.5 ft.lbs. 9, 10 10 ft.lbs. Tools: torque wrench (19mm) + adjustable wrench
3. Piping Inspection: Check piping routes and valve switches.
4. Power control check (take Ionpure original power control as an example):
1.) Check if the rectifier and display board Jumper are selected correctly:
A. ACV: For example, LX30, if you need 660V, select 660V (**** there are three options: 440, 550, 660).
B, DC: Select the maximum current limit, for example: LX select 10A (*** there are 2.5, 4, 6.5, 10A four options). The selected current must be the same as the selection on the display board.
C. Frequency: Select 60Hz or 50Hz.
2.) Check the transformer to control board wiring (T1, T2) and to module wiring.
3.) Check the ground wire (DC-).
4.) Select the control mode: constant current control (A) or constant voltage (V) (constant current control is recommended).
5.) Check the flow switch.
5. Confirm the capacity of the influent pump: the influent pump's drawdown flow rate should meet the system's required flow rate, and its head should be able to overcome the pressure loss of the equipment and piping (the pressure loss of the LX module is about 1.5-2 bar (related to the treatment capacity)).
Jumper adjustment on the back of Ionpure display board Jumper adjustment and wiring on the back of Ionpure control board
(2) Precautions for commissioning
1. Confirm the operation of RO system is normal? It is recommended to switch the influent water to EDI system only after the RO system operation is stabilized to avoid the poor water quality at the beginning of RO startup, which may affect the module performance.
2. Test the quality of incoming water: test the quality of incoming water to confirm that the quality of incoming water meets the requirements, the test items include at least electrical conductivity, total hardness, silica, total chlorine and CO2. If any one of the water quality is not consistent with the aforementioned requirements of incoming water quality, that is, the water can not be drawn into the EDI module, and you need to check the pre-treatment for problems. If the CO2 concentration of the influent water is too high (more than 5ppm), it is not recommended to return the concentrated water to the tank before the RO system (unless the CO2 is removed) to avoid the accumulation of CO2, which affects the quality of the produced water.
3. Pipe cleaning: Note: In order to avoid residual pipe debris and other pollutants in the pipeline into the module caused by clogging, it is recommended that the original factory attached to the import and export of the red head before the test run (including rack piping), do not take out the red head (but before the test run to be sure to take out the object). Before entering the module, make sure there is no contamination in the pre-treatment piping. It is recommended to disconnect the water inlet connector of the module before startup and flush the pipeline with RO water.
4. Test the safety protection devices:
1.) Test the influent pump and EDI linkage: Test the influent pump and EDI linkage, so that the EDI will turn on the power only when the influent pump is turned on, and turn off the influent pump when the EDI power is not turned on for a certain period of time.
2.) Flow switch test: Before starting the flow switch needs to be tested to see if the flow switch will act, that is, when there is no water the power supply is turned off, and when the water is turned on to start the flow switch (the circuit is connected), the DC power supply is supplied to the module.
5. System startup precautions
1.) When the above safety protection test is completed, check the pipeline valve switch again to make sure that the valve switch is correct before starting the inlet pump.
2.) After the inlet pump is started, check the power supply to see if it starts properly. For example, in the case of the Ionpure original display board, the light on the display board will be jumped from Standby to On, if not, turn off the inlet pump first, and check the flow switch and the wiring is normal.
3.) Inlet pump start, with a manual valve (preferably with a diaphragm valve, to facilitate the adjustment) to adjust the water production and concentration of water flow, the initial production of water to take the lead in adjusting to 90%.
4.) When you first start up, adjust the current down (e.g., 0.5A), make sure that the water flow and power supply is not a problem, and then slowly adjust the current to the value of the current required by the soft calculator (and the quality of the incoming water, water-related), and then observe the voltage and the quality of the discharged water. The water quality may be poor at the beginning of the start-up, do not because of poor water quality, that is, hastily adjust the current to far more than the value calculated by the software. For example: the inlet water quality conductivity - 10μs/cm, CO2 - 8mg/l, SiO2 - 0.2mg/l when the current required by the calculator software is 2.43 amps, then set the current at about 2.5 amps can be (calculated when the water quality is the worst), do not adjust the current more than this value (calculated when the water quality is the worst), do not start to adjust the current (the water quality may be poor). Do not adjust the current to exceed this value (e.g. 4.0 amps) to avoid damage to the module.
5.) Observe the inlet and outlet water pressures, and adjust the manual valve so that the produced water pressure is slightly higher than the concentrated water pressure of about 2-5psi (if the produced water outlet pressure is lower than the concentrated water pressure, it will affect the quality of the produced water).
6.) In order to avoid EDI start-up poor water quality, it is recommended to set up two automatic control valves at the end of the water production, and PLC control: when the quality of water production is lower than the requirements of the EDI water back to the EDI tank, when the water quality is higher than the set water quality, before switching to the next treatment device.
7.) When the system in a stable state (water quality meets the requirements and stable operation), should be based on the operating manual 4.0 Chapter 4.0 Chapter 4 of the last data sheet attached to the record of operating information (test items at least need to include the temperature of incoming water, electrical conductivity, total hardness, CO2, resistance value of the produced water, the import and export flow rate and pressure (including the concentration of the end), the operation of the voltage, current), in order to facilitate the subsequent maintenance of the equipment.
Three, operation and maintenance notes
1. Should fill out the IP-LX system log sheet every day, in order to find out if there may be a warranty failure or damage to the membrane stack.
2. Should be at least every six months on the membrane stack of membrane block appearance inspection, check for water leakage or salt deposition; and regularly tighten all electrical connections and in accordance with the provisions of Chapter 3.2, check the membrane stack bolt torque.
3. Membrane stacks may need to be cleaned under the following circumstances:
Produced water pressure drop increases by 50% with no change in temperature or flow rate;
Concentrated water pressure drop increases by 50% with no change in temperature or flow rate;
Produced water quality decreases with no change in temperature, flow rate, or influent conductivity;
Membrane stack resistance increases by 25% with no change in temperature. Please refer to the operation and maintenance manual for cleaning method.
4. In case of module failure, please refer to the membrane stack failure test procedure in the original operation and maintenance manual or contact your local en-link service provider.
4. Pre-treatment Design for EDI System Stability and Water Quality Improvement In order to increase the stability of the EDI system and improve the quality of the produced water, the following equipment can be added to the pre-treatment
1. CO2 Removal Equipment: Generally, the RO water contains a certain amount of CO2, and if the concentration of CO2 in the influent water can be reduced, it will help improve the quality of the water and reduce the possibility of scaling;
2. When the raw water hardness and silica concentration is relatively high or large changes, in order to avoid large changes in raw water quality or softening system problems, RO water hardness, silica concentration exceeds the EDI influent standard, or to reduce the possibility of EDI module scaling, it is recommended that the pre-treatment using Two pass RO system.