1、 Unit conversion of reverse osmosis membrane

1. Unit conversion of size, pore diameter, diameter, area and water yield of imported reverse osmosis membrane?

A: in China's water treatment process, the length unit is generally expressed in mm, and the calibration unit of imported equipment needs to be converted (in = inch, ft = foot): 1in = 25.4mm, 1ft = 304.8mm, 12in = 1ft;

Reverse osmosis membrane pore size: 10-6in = 2.54x10-6mm;

Area: 1ft2 = 144in ² = 929x10-4m ²= 92903mm ²， 1 in2=6.45 x10-4m ²= 645.2 mm ²； Flow: UK GPD (Gal / D, Gal / D) = 4.546 L / D = 5.26 * 10-5 L / S; GPD (Gal / D, Gal / D) = 3.785l/d = 4.381 * 10-5l/s in USA;

Pressure: 1B / in ²（ Psi, psi) = 0.0703 kgf / cm ²， Legal unit: 1pA = 1n / M ²， 1Mpa=106pa，

1psi=6.895kpa=6.895x10-3Mpa； When the pressure of reverse osmosis is 600 psi, it is 4.14 MPa.

1 bar (commonly known as 1 kg) = 0.1 MPa; 1mmHg=0.1333kpa；

The content of free chlorine is less than 1ppm, that is, the content of free chlorine is less than 1mg / L.

2. Temperature conversion（ Thermodynamic temperature, centigrade temperature, Fahrenheit temperature)

A: thermodynamic temperature (k) = centigrade temperature + 273.15;

℃=5/9（℉-32），℉=9/5℃+32；

The relative humidity can be obtained by dry bulb thermometer and wet bulb thermometer; You can also look up the table.

                          3. Conductivity correction?

The conductivity can be corrected with 0.01 mol / L and 0.02 mol / L potassium chloride solution. The specific method is to place the conductivity electrode to be corrected in the

In 0.01 mol / L or 0.02 mol / L KCl solution, the temperature of KCl solution was kept at different temperature by precision constant temperature water bath

Compared with the following table, the electrode constant of unknown constant electrode can be measured and verified.

Conductivity of potassium chloride solution with different concentration and temperature (US / cm)

    2、 Loading element:

1. Remove the end plate and thrust ring in the system pressure vessel.

2. Wash the opened pressure vessel with clean water to remove dust and sediment.

Note: if further cleaning is needed, make a mop large enough to fill the inner diameter of the pressure vessel, and let the mop absorb 50% glycerin

Drag back and forth in the pressure vessel until the inner wall of the pressure vessel is clean and lubricated.

3. Install the end of the membrane element without salt water seal ring from the direction of the water inlet end of the pressure vessel, and push the element about half way.

Note: it is stipulated that the components must be installed from the inlet end of the pressure vessel.

4. Confirm whether the direction of the brine seal ring on the element stress resister is correct. That is, the opening direction of the sealing ring should face the water inlet direction.

Insert the joint between components into the central pipe of component water production. Before installing the joint, a small amount of oil can be applied on the O-ring of the joint

Glycerin (unless otherwise not permitted).

5. Install the second component and the connecting connector in turn, hold the component carefully, do not let the connecting connector bear the weight of the component, and push the component away

Enter the pressure vessel until about half of the element is exposed.

6. Repeat steps 4 and 5 until all components are installed in the pressure vessel. The length of the components and the pressure vessel determines the number of components in a single pressure vessel.

7. Install the thrust ring at the concentrated water end of the pressure vessel, and position the thrust ring according to the schematic diagram of the pressure vessel manufacturer.

8. Install the end plates at both ends of the pressure vessel as follows:

a) Carefully position the concentrated water end plate of the pressure vessel, align the components, push the end plate assembly, carefully place the O-ring on the transition joint (adapter) between the components and the end plate, and insert the transition joint into the components to avoid twisting or overturning the O-ring.

b) Rotate and adjust the end plate assembly to align with the external connecting pipe.

c) Install the end plate snap ring according to the pressure vessel manufacturer's schematic diagram.

d) Push the RO element from the inlet side to the concentrated water side.

e) Before installing the water inlet end plate, it is recommended to adjust the gap between the element and the end plate with adjusting plate. This step can help to prevent the components from moving and the impact between components during the system startup and shutdown.

f) For each pressure vessel in the system, install the components in the same way as in steps a) to e).

9. Connect all external pipes.

3、 Disassembly of components:

1. First, remove the external hard pipes at both ends of the pressure vessel. If necessary, please refer to the sketch of the pressure vessel manufacturer. Mark all the removed parts with numbers and place them in order.

2. Remove the vessel end plate assembly from both ends of the pressure vessel.

3. Push the RO element out of the pressure vessel from the inlet end of the element, one element at a time. When the element is pushed out of the pressure vessel, catch the element in time to prevent damage to the element or personal injury.