Commissioning of diaphragm electrolyzer
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This post was last edited by sunjl1981 on 2013-1-6 at 23:50. After dozens of new diaphragm electrolyzers were put into operation simultaneously, the electrolyte concentration in each individual electrolyzer as well as in the main pipelines was low; it remained below 90 g/l even after five days of operation. What are the possible reasons for this phenomenon, and how should it be addressed? # ， ， &
It was soaked in saltwater.:lol :lol
1. The concentration in the main pipe is that brought in by the new tank； 2. There are too many new slots in the system; generally, slot removal stops one week before shutdown to ensure the quality of the new slots ； 3. After the new cell was installed, was the water level in the electrolytic cell adjusted when the concentration in the main pipe was low? Did this affect the balance of membrane formation in the new cell? ； 4. Reduce the amount of liquid removed from the tank, gradually increase the concentration, adjust the water level, and after compacting the membrane in the new tank, carry out further optimization adjustments. :lol
This is a normal phenomenon; there’s no need to worry too much about it. If the concentration in a single cell is too low after one week in the tank, for example below 60 g/l, it is necessary to consider whether there is an issue with the quality of film formation – it could be due to an incorrect ratio of long to short fibers, or perhaps the film layer is too thin. This is a common issue when there are too many new slots; it will return to normal after running for some time. In some factories, there is a makeshift method involving adding a small amount of salt sludge to tanks with very low concentrations (provided that the hydrogen content is low and the chlorine purity is satisfactory), but this is not recommended. If the concentration is low, the hydrogen content is not up to standard and the purity is also not satisfactory, then it must be a problem with film formation.
This is a common issue with newly grooved surfaces; the situation improves after some time has passed. As long as hydrogen levels in the chlorine are under control and safety is ensured, it is possible to lower the liquid level slightly, increase the hydrogen pressure, and reduce the pressure in the anode chamber. If the hydrogen content in chlorine is too high, it’s a problem with membrane adsorption. I’m not sure if you’re using the full current level; it’s advisable to use the maximum possible current
It may be due to inadequate membrane adsorption; the reasons for this are, on one hand, an excessive amount of short fibers, on the other hand, a low vacuum level, and furthermore, too rapid an increase in vacuum pressure during the adsorption process. One approach is to raise the liquid level, use pressure to compress the membrane, and then lower the liquid level to the minimum, which can increase the concentration somewhat.
While ensuring the presence of hydrogen and oxygen, it is possible to consider raising the liquid level
An appropriate amount of 31% hydrochloric acid can be added to the anode chamber. The principle behind this is that asbestos fibers are composed of layers of magnesium hydroxide and SiO2; in a saltwater solution at temperatures as high as 90 degrees, not only are the asbestos fibers eroded by H+, but the impurities deposited on the membrane also react with hydrochloric acid to form MgCl2 and Ca(HO)2 precipitates. These precipitates reduce the porosity of the membrane and its permeability, thereby increasing the concentration of NaOH
What is described on floor 8 is a method, but it does not take into account the fact that adding acid to the anode chamber increases the acidity of the anode solution, which can corrode the electrodes. Moreover, once the concentration rises as a result of using this method, the situation becomes uncontrollable, leading to a shortened lifespan of the tank; therefore, it is not advisable to use this method under normal circumstances.