Fault Diagnosis of Reverse Osmosis Water Treatment System

Fault Diagnosis of Reverse Osmosis Water Treatment Systems

During operation, reverse osmosis water treatment systems can malfunction due to various factors, including complex operating conditions, inadequate system design, improper pretreatment equipment configuration, unsuitable water treatment reagent selection, abnormal fluctuations in the system's water source, and various problems encountered during operation. These factors can lead to issues such as decreased desalination rate, reduced permeate flow, increased inlet pressure, and increased energy consumption per unit of water production. Kaiyuan Hengye leverages its years of experience in reverse osmosis system design, installation, and operation to employ professional technical analysis methods to conduct detailed analyses and diagnoses of various faults encountered during the operation of reverse osmosis water treatment systems. Simultaneously, solutions are provided through static and dynamic simulation tests.

The operation of a reverse osmosis unit is a process of generating historical data. During this process, changes in various performance characteristics of the reverse osmosis system and various factors that may lead to system malfunctions are often reflected in this data. In particular, analysis of the following historical data is crucial:

1. Changes in routine analysis data of turbidity, SDI, and COD of the reverse osmosis unit feed water;

2. Reverse osmosis unit feed water pressure, intermediate stage pressure (for a one-stage, two-stage system), concentrate pressure, and product water pressure;

3. Reverse osmosis unit feed water conductivity, product water conductivity, feed water flow rate, and product water flow rate;

4. Changes in operating parameters of the reverse osmosis pretreatment system (including turbidity and pressure);

5. Problems typically discovered during equipment maintenance and the methods used to address them, etc.

The above data is often insufficient. More information is needed depending on changes in on-site conditions. After obtaining the above data, specialized processing methods (such as standardization) are often required to observe operational trends and propose solutions.

When historical data analysis fails to accurately reflect actual fault phenomena, on-site investigation is crucial. Investigation items include:

1. The rationality of the reverse osmosis unit's design;

2. The rationality of the reverse osmosis pretreatment system design;

3. The completeness of the operating procedures;

4. Whether the reverse osmosis system's chemical dosing is normal, whether the added chemicals are compatible with the system, and whether the pretreatment flocculant is compatible with the reverse osmosis additives (scale inhibitors, dispersants, bactericides, reducing agents);

5. The configuration of the reverse osmosis pre-filter (security filter) cartridge, etc.

The above data is often insufficient; more information is needed depending on changes in the actual situation.

While analyzing the above two aspects, further analysis of the source water, reverse osmosis feed water, and other possible water source qualities is necessary. Analysis items mainly include: turbidity, SDI, COD, Ca2+, Mg2+, Sr2+, Ba2+, SO42-, alkalinity, silica, etc. In our central laboratory, all these water quality analysis items that may cause system failure will be tested one by one; at the same time, the influent and effluent water quality and flow rate of each membrane shell (reverse osmosis pressure vessel) in the reverse osmosis unit will be analyzed in more depth.