Is the pressure of the Kay membrane always high?

There are many factors that can cause an increase in the pressure across the Kaier membrane, including whether sodium hypochlorite is added as required (the level of organic matter, as well as algae and microbial substances). Whether the quality of the pre-treatment saline is normal is important; issues such as low reverse osmosis transmittance and incomplete acid cleaning can all lead to an increase in the pressure across the membrane.

The normal pressure for Kay membranes is around 0.03–0.06 MPa; when the pressure rises to 0.07 MPa, it affects the flow rate of the output water. I am referring to the method of feeding liquid using a high-level tank. The normal pickling cycle is about half a month. If the pressure rises rapidly in a short period of time, there is definitely a problem with the pretreatment process; it is generally believed that organic substances and magnesium hydroxide in the brine can clog the membrane. Therefore, it is important to control the amount of sodium hypochlorite added to ensure a trace amount of free chlorine in the pre-reactor tank. At the same time, the pressure and liquid level of the pressurized dissolved air tank, as well as the amount of ferric chloride added, must all be carefully controlled to prevent turbidity from occurring in the pre-treater. After sodium hypochlorite decomposes the large molecular organic substances, ferric trichloride is used for flocculation to remove them; I believe this process should be feasible. However, the parameters related to the original salt still need to be controlled

2. Precursor solution turbidity. a. Unstable NaCl content in the brine: Analyze the concentration of the brine promptly, and adjust the amount of fresh water added at the brine bypass tank to ensure that its concentration is within the acceptable range. In case of special circumstances, follow the procedures outlined in item 1 of Table 1. b. The NaOH content in the brine is unstable; analyze it promptly and adjust the amount of NaOH added, remove sludge in appropriate amounts, and accelerate the replacement of substandard brine. c. When the temperature of the brine is low, its viscosity increases, resulting in poor clarification effects. Adjust the brine preparation temperature to between 55 and 59 degrees; 10 minutes before adding salt, bring the temperature to between 60 and 62 degrees, and restore it to the normal range immediately after salt addition. d. Large fluctuations in the flow rate of brine: 1. Check the flow rate of the pressure pump P-404, and take action according to item 12 in Table 1 ； 2. Check whether the control of the release valve AV5103 is functioning properly; if there are any issues, carry out repairs promptly ； 2 e. The dissolved air capacity of the brine is insufficient; adjust the liquid level in the pressurized aeration tank to 60–75% and the pressure to 0.2–0.3 MPa. f. The liquid level in pressurized aeration tank Z-402 is too low, allowing air to enter the preprocessor and disrupt the sludge layer. Adjust the liquid level in the pressurized dissolved air tank to 60–75% of its capacity; ensure timely sludge removal – carry out sludge removal at regular intervals. The order of sludge removal is incorrect; make sure to remove sludge from the upper part first before dealing with that from the lower part. The flow rate of FeCl3 is either too low or too high – adjust the amount of FeCl3 added, and it’s advisable to make the saltwater a light yellow color. The quality of the raw salt is poor – use high-quality raw salt for preparation. The salt sludge content in the brine is high. 1. The filter cloth in the filter press has holes, which results in a high amount of salt sludge in the filtrate, which then ends up in the brine storage tank ； Replace damaged filter cloths in a timely manner, and maintain the liquid level in the V-401A/B brine storage tanks at over 50% to prevent the salt sludge at the bottom of the tanks from being disturbed, which could cause the brine to become turbid. Depending on the situation, those tanks with excessive salt sludge accumulation should be taken out of use for cleaning. 2. Dispose of the salt sludge in the V-430 filtrate tank in a timely manner ； 3. Reduce the entry of sediment and other impurities into the brine storage tank ；

In simple terms, the high pressure on the Kay membrane is mostly caused by improper operation, which leads to turbid water coming out of the pre-treater. While improving operational management, it is also important to pay attention to the maintenance of the Kay membrane; it is normal to carry out acid cleaning every 7 to 20 days. As for the filtration pressure of the Kay membrane, I believe that the lower it is, the better. We usually set it at 0.01MPa to 0.02MPa. Additionally, make sure that the Kay membrane is not contaminated by oils. It should also be mentioned that the effect of organic macromolecules, as you mentioned, is something I have truly never seen before. As long as sodium hypochlorite is added in accordance with the requirements, this problem should not arise. Moreover, too much sodium hypochlorite should not be used, as this will not only place significant stress on the corrosion protection of the equipment and pipelines in the brine system but also lead to an increase in the amount of sulfates in the system.

Poor quality of pre-treatment saline; the inlet valve of the membrane filter is opened too wide; inadequate membrane cleaning