The first step   preparation

1. Prepare all possible tools for construction

Including: rubber boots, rubber gloves, protective glasses, wrench (remove the end cover of module housing), pipe clamp, glycerin, etc

2. Clean the upstream water inlet pipeline;

3. Carefully evalsuate the quality of the influent water;

4. Check the pipeline for leakage;

5. Prepare water soluble lubricant (chemically pure glycerol);

6. Ensure all parts and chemicals are complete;

7. Check the operation of the pretreatment system and the water outlet.

Step two   Disassembly of old reverse osmosis membrane and installation of new membrane

1. Disassemble the pressure vessel of reverse osmosis membrane, and store all the end caps and parts in order

2. Take out the old reverse osmosis membrane components in the pressure vessel and wash the pressure vessel clean.

3. Take out the new membrane element and check whether the position and direction of the brine seal ring on the element are correct (the opening direction of the brine seal ring must face the water inlet direction), as shown in the figure below:

4. Push the end of the membrane element without brine seal ring into the membrane shell from the water inlet end of the pressure vessel in parallel until the element is exposed about 10 cm outside the water inlet end of the pressure vessel. See the figure above:

5. Insert the connecting pipe between the components into the central pipe. Before installation, apply a small amount of glycerin lubricant on the "O" ring of the joint. If not, directly wet it with qualified pretreatment water.

6. Take out the second membrane element, check whether the position and direction of the brine sealing ring on the element are correct, hold the element, insert the connecting pipe on the first element into the central pipe of the element, and push the element into the pressure vessel in parallel until the second element is about 10 cm outside, as shown in the figure below:

7. Repeat the steps until all the components are installed in the pressure vessel and transferred to the concentrated water end. Install the connecting pipe on the central pipe of the first component. The length of the component and the pressure vessel determines the number of membrane components that can be installed in a single pressure vessel. During installation, install the thrust ring on the concentrated water end of the pressure vessel.

8. Check the "O" ring on the component adapter, insert the component adapter into the concentrated water end plate, align the component connecting pipe, and push the concentrated water end plate assembly into the pressure vessel in parallel;   Rotate and adjust the concentrated water end plate assembly to align it with the external connecting pipe; Install the end plate snap ring

9. Push the membrane element from the water inlet side to the concentrated water side until the first membrane element is firmly contacted with the concentrated water end plate.

10. Install the water inlet end plate. Before installing the water inlet end plate, in order to prevent the axial movement of the components and the impact between the components during the system startup and shutdown, the adjusting plate (5mm thick) can be used to adjust the gap between the membrane components and the end plate.

11. Repeat the above steps, install membrane elements in each pressure vessel and connect all external water inlet, concentrated water and produced water pipelines.

The third step   Equipment debugging

1. Inspection and preparation before commissioning, including the following parts:

① Configure measuring instruments and calibrate them;

② The sampling points of each link of the system are set, and the interlocking, delay and alarm devices are set correctly;

③ Check the connection between pressure vessel and cleaning pipeline, and fasten all joints;

④ No load test run of water pump and other rotating equipment to ensure correct steering and good lubrication;

⑤ Open the produced water discharge valve and the concentrated water discharge valve;

⑥ Before starting the high-pressure pump, adjust the opening of the outlet valve of the high-pressure pump, and control the water inflow of the membrane system to be less than 50% of the water inflow of the operation.

2. Check all valves and ensure that all settings are correct. The effluent discharge valve, inlet control valve and concentrated water control valve of membrane system must be fully opened.

3. The air in membrane element and pressure vessel shall be driven away by low pressure and low flow qualified pretreatment effluent. All produced water and concentrated water in the process shall be discharged to sewer.

4. During flushing operation, check all valve and pipe connections for leakage.

5. The dry film system should be washed continuously at low pressure for more than 6 hours or first for 1-2 hours, and then for about 1 hour after soaking overnight. It is not allowed to add scale inhibitor in pretreatment part during low pressure and low flow flushing.

6. Reconfirm that the product water valve and concentrated water control valve are in the open position.

7. When starting the high-pressure pump for the first time, the inlet control valve between the high-pressure pump and the membrane element must be close to the full closed state to prevent the impact of water flow and water pressure on the membrane element.

8. Start the high pressure pump.

9. After the high-pressure pump is started, the inlet control valve at the outlet of the high-pressure pump should be opened slowly to evenly increase the concentrated water flow to the design value, and the pressure rise rate should be less than 0.07 MPa per second  。 10. While slowly opening the inlet control valve at the outlet of the high-pressure pump, slowly close the concentrated water control valve to maintain the concentrated water discharge flow specified in the system design. At the same time, observe the produced water flow of the system, and gradually adjust to make the recovery rate reach the design value.

11. Check whether the dosage of all chemicals is consistent with the design value, and determine the pH value of influent water.

12. The system runs continuously for 1 hour. When the produced water is qualified, first open the qualified produced water delivery valve, and then close the produced water discharge valve to supply water to the subsequent equipment. Record all operation parameters of the first group. The above adjustment is generally carried out in manual operation mode, and the system will be converted into automatic operation mode after stabilization.

13. After 24-48 hours of continuous operation, check all recorded system performance data, including inlet pressure, differential pressure, temperature, flow rate, recovery rate and conductivity. At the same time, the influent, concentrated water and total system produced water were sampled and analyzed. Confirm that the equipment operates normally and the construction is completed.