Installation of EDI membrane blocks

I. Precautions during installation

1. Check the torque of the membrane blocks. If the nuts of the connecting bolts become loose during transportation, the pressure of the water inlet may damage the module. Therefore, before filling the module with water, the bolt torque must be checked and the bolts must be tightened.
2. Before touching the inside of the junction box, make sure that the AC power is disconnected. To eliminate the risk of electric shock, make sure that the ground wires are properly connected.
3. The pipes prepared for installation must be inspected and ensure that they do not contain debris brought by storage or debris left by cutting tools.
4. No tools, such as nuts, screws, etc., should be placed above the module to prevent the above items from damaging the membrane blocks.

II. Electrical safety
EDI membrane blocks work by applying a DC voltage to a set of conductive fluids containing water. Moreover, EDI systems are generally installed in humid places. Because of this, it is critical to ensure the electrical safety of the system and prevent accidents in design. Note that the user is responsible for ensuring the safe design and safe installation of the system and for training operators.

III. Key considerations for system design

1. Electrical installation should be completed by qualified and trained technicians. Electrical installation should be carried out in accordance with local regulations.
2. Proper grounding of the power supply and membrane block is very important. A ground leakage protection switch circuit can be used, but it may not be reliable when working under a DC power supply.
3. The grounding performance should be tested after installation on site to ensure that there is no voltage on any metal surface during operation.
4. The feed water and concentrate water contain ions that can conduct electricity and thus generate current. These water flows should be directly connected to the ground by installing a conductive material, generally through a T-shaped tee.
5. Proper training and hazard warnings should be posted at the installation site and installed equipment.

IV. Chemical safety
The electrochemical reactions at the anode and cathode can produce gases under normal conditions. The oxidation reaction at the anode produces acid, O2 and Cl2, and produces electrons. The reduction reaction at the cathode can produce OH- and H2, and consumes electrons. These gases and electrons will converge in the anode water and then be discharged with the concentrate water. Although the amount of gas generated is very low and will not cause danger or harm to the human body, it is still recommended that the installation environment of EDI should be well ventilated.

V. EDI membrane block handling

1. Since the EDI membrane block has a certain weight, please be careful when handling it during installation to prevent it from being dropped and damaging the sealing structure of the membrane block.
2. Do not allow water pipes or electrical connections to exert force when moving the membrane block.
3. Do not fix the front and back ends of the module at the same time, as this will affect the adjustment of the distance between the membrane plate.

VI. Check module torque
By adjusting the torque of the membrane block fastening bolts, the membrane block partition spacing can be changed, which is not only related to maintaining internal pressure to ensure the quality of the outlet water, but also related to preventing internal and external leakage of the EDI membrane block. The partition spacing has been adjusted before leaving the factory. Excessive adjustment of the partition spacing may cause damage to the membrane block. Usually, membrane block leakage is mainly caused by loose fastening bolts at both ends of the membrane block, which can be solved by checking and re-tightening the bolts. The membrane block should not leak under normal pressure. If leakage is found, the machine should be stopped to check the leakage location. If the spacing becomes larger, it can be adjusted appropriately. If the leakage problem cannot be solved after adjustment, please contact the company’s technical staff immediately.

VII. Pipe connection and electrical connection

1. Pipe connection
   Before connecting to the EDI membrane block, it is necessary to ensure that all upstream pretreatment equipment and pipelines have been thoroughly rinsed with clean water without particulate impurities. Before installation, it is very important to protect the threads to prevent damage and subsequent leakage. When connecting the pipe fittings to the module, the pipe fittings on the main membrane block should be clamped with a wrench to prevent them from being damaged under torque. Be careful to avoid over-tightening, which may cause damage to the branch pipe or thread.
2. Power connection and membrane block grounding
   The DC power supply should be firmly connected to the positive and negative poles of the EDI membrane block. The anode attracts anions and the cathode attracts cations.
   The membrane block itself is grounded by fixing it to the bracket, and the power supply is grounded through the main DC system. All conductive parts of the membrane block are connected to the ground wire and connected to the ground at the appropriate position.
   Note: The membrane block itself is grounded through the power cord. The output of the EDI power supply has dangerous high voltage. When connecting to the junction box, pay attention to the installation to ensure that the EDI power supply is in the disconnected state.