How to replace Ro Membrane 8040?

Preparation and Procedure Before Installing an RO Membrane

The structure of reverse osmosis (RO) membranes can be classified into two types: asymmetric membranes and homogeneous membranes. Currently, the primary materials used for RO membranes are cellulose acetate and aromatic polyamide. The membrane modules are available in various configurations, including hollow fiber, spiral-wound, plate-and-frame, and tubular types. These membranes are widely applied in chemical unit operations such as separation, concentration, and purification, and are mainly used in pure water production and water treatment industries.

The principle of reverse osmosis technology is to apply pressure greater than the osmotic pressure of the solution, forcing water to pass through a semi-permeable membrane while preventing other substances from passing through, thereby achieving separation. Due to the extremely small pore size of RO membranes, they can effectively remove dissolved salts, colloids, microorganisms, organic matter, and other impurities from water. The system offers advantages such as high water quality, low energy consumption, no pollution, simple process design, and easy operation.

Preparation Work for Membrane Element Installation

Confirm that the pretreated water meets the feed water requirements of the RO system.
Flush the feed pipeline and the inside of the membrane housing; ensure cleanliness and that no foreign matter is present.
Insert the membrane element from the feed end toward the concentrate end to about two-thirds of its length, and record the element serial number.
Check the "O"-ring seals of the interconnectors and lubricate them with glycerin.
Push the membrane element fully into the housing toward the concentrate end.
After all membrane elements are installed, measure whether there is any gap between both ends of the membrane elements and the end plates of the housing to prevent movement or impact during operation.
Do not use petroleum jelly, organic solvents, or cationic surfactants.

RO Membrane Element Installation

First, open the membrane packaging and install the brine seal. Ensure the correct installation direction: insert the membrane element from the feed end toward the concentrate end. Reverse installation may damage the brine seal. The concentrate end without the black sealing ring should enter the pressure vessel first, followed by the feed end with the black sealing ring. Incorrect installation may result in insufficient cross-flow velocity during operation, increased concentration polarization, and accelerated fouling.

Use the correct lubricant, with glycerin (glycerol) recommended. The use of detergents, petroleum jelly, or other oil-based lubricants is strictly prohibited. Detergents, as cationic surfactants, can reduce the water flux of negatively charged membrane elements, while other oil-based lubricants may cause embrittlement and damage to the membrane element's central tube.

Before completing the installation, all installation gaps must be eliminated. Even qualified pressure vessels and membrane elements may have dimensional tolerances.

If gaps exist, membrane elements may move back and forth inside the vessel during operation, impacting the end plates and causing damage. Before locking the feed-end end cap, spacers must be installed on the adapter between the membrane element and the pressure vessel to eliminate any installation gap.