Operating Conditions and Debugging of Reverse Osmosis Equipment

The RO equipment consists of a reverse osmosis membrane (RO), a high-pressure pump and a security filter set up to protect the reverse osmosis membrane. The security filter is equipped with a filter element with a filter pore size of 5μm. These filter elements will filter out any particles larger than 5μm in size. Protect the downstream RO membrane, otherwise the surface of the RO membrane will easily scale. At present, the most commonly used permeable membrane category is polyamide membrane, and the membrane type is roll composite membrane. The salt removal rate of this type of membrane can reach 99.5%. Since the RO membrane is easily affected by the pH value, residual chlorine and water temperature in the water, there are strict requirements on the inlet water quality before the RO membrane operates:

PH value: 3~10

Residual chlorine value: <0.1mg/L

SDI15 value: <5.0

Water temperature: <45 ℃

If any of the above indicators exceeds the range, it may deform the permeable membrane, thereby affecting the quality of the effluent water and shortening the service life of the membrane. In addition, different types of membranes have different requirements for the quality of influent water. Before debugging, you can confirm according to the instructions provided by the RO membrane manufacturer.

Preparation before operation of reverse osmosis equipment

RO is a high-pressure operation equipment. Before operation, for the protection of equipment and instruments and for safety, the opening state of the valve should be confirmed and adjusted in strict accordance with the operating procedures. The specific operations are as follows:

1. Fully open the water inlet valve of the security filter and open the water inlet valve of the high-pressure pump

2. Open the water outlet valve of the high-pressure pump one turn

3. Open the RO inlet valve one turn

4. Rotate the needle valve on the concentrated water pipe three and a half turns

5. Fully open the product water outlet valve and concentrated water outlet valve

6. Close all sampling valves and cleaning valves

7. Open all pressure display valves to a half-open state

Ro Equipment

Test operation and debugging of reverse osmosis equipment

When the above conditions are confirmed to be satisfied, the high-pressure pump can be started and put into trial operation. Since RO is also a liquid-liquid separation equipment, only when the feed water pressure is higher than the osmotic pressure, the water can pass through the reverse osmosis membrane to achieve the desalination effect. The driving force of this phenomenon comes from the pressure difference (ΔP) between the feed water (concentrated water) pressure and the osmotic pressure (depending on the type and type of the permeable membrane). The ΔP of this part can be determined by the stop valve (valve 5) installed at the RO inlet. ) And the pressure regulating needle valve (valve 13) installed on the concentrated water line to adjust the control. Firstly, adjust the total water intake (the sum of the readings of the flow meter 11 and the flow meter 12) to the designed water intake according to the RO inlet stop valve. Then use the pressure regulating needle valve (valve 13) to accurately adjust the produced water flow and concentrated water pressure. When the produced water is smaller than the design value, it means that the feed water (thick water) pressure is too small, that is, the ΔP value is too small. Turn the needle valve down to increase the pressure of the concentrated water (inlet water) until the water production is equal to the design value.

Reverse osmosis is divided into two parts, one part is the pretreatment debugging, the other is the reverse osmosis host debugging part. The pretreatment is mainly positive and negative washing of quartz sand and activated carbon, so that fine sand and impurities are washed away, and the amount of influent water is controlled. The main engine debugging is to adjust the flow and pressure of the inlet and outlet water, which can be summarized as follows:

1. Analyze and test the water inlet of the device, and the results show that it meets the water inlet requirements before the device can be debugged.

2. Adjust the pressure control system of the high-pressure pump.

3. Check whether the connections between all pipelines of the device are complete, whether the pressure gauges are complete, whether the low-pressure pipeline connections are tight, and whether there is a shortage.

4. Fully open all pressure gauge switches, main water inlet valve, concentrated water discharge valve, and product water discharge valve.

5. Start the pretreatment equipment and adjust the water supply to be greater than the total water intake of the device.

6. Backwash and forward the sand charcoal filter until the water is clear.

7. Start the high-pressure pump, and slowly open the total water inlet valve of the device. The total water inlet pressure of the control device is less than 0.5Mpa, flush for 5 minutes, and check whether the high and low pressure pipelines and meters are normal.

8. Adjust the inlet valve and concentrated water discharge valve to make the inlet water pressure reach 1.0～1.4Mpa.

9. Check the product water conductivity, open the product water outlet valve and close the product water discharge valve when it meets the requirements.

10. The debugging of the RO device is a manual single-step Cao group. After the operation is normal, it can be switched to the automatic state, and it is automatically controlled by the online instrument and PLC.

11. Start the regeneration system and see if the regeneration system works normally.