Use and improvement of brine secondary filter
Abstract: Through the analysis of the use of polyethylene pipe filter, the improvement is briefly introduced. The equipment works well and improves the current efficiency. Key words: brine PE filter improvement The annual production capacity of diaphragm caustic soda in our factory is 130,000 tons, and 214 sets of 30-IQ diaphragm electrolyzers are used. The running current is basically 50-52 kA. In the past, the refined brine sent to the electrolyzer of our factory was only filtered once by the valveless filter device, and the pipeline for conveying the refined brine was ordinary carbon steel pipe, and the quality of the brine was difficult to guarantee. In November 1998, after the three DJS-150 brine secondary filtration devices were put into production, our factory achieved good results in improving the quality of the brine, improved the operation of the electric tank, and improved the current efficiency. However, after the filter unit was operated for 4 months, problems occurred, which restricted the stable operation of the electrolytic cell. In this regard, our factory and the production plant of the brine secondary filtration device jointly tackled the problem and carried out technical improvements to ensure efficient and stable operation of the device. 1 There is a problem After March 199, the three filter housings and the collecting tank began to show serious corrosion. At the same time, the filtered polyethylene tube (hereinafter referred to as PE tube) appeared aging and brittle. Although our factory has undergone many overhauls, it has brine. The filter still can not maintain normal use, and the 3# filter was deactivated in July 1999. In January-February 2000, the filter tube of the filter was partially dropped due to the operation, and the brine flowing into the electrolysis tank appeared several times. The enthalpy phenomenon, the quality of the brine in the electrolytic cell is not obtained, and the current efficiency is inevitably greatly affected. 2 Cause analysis 2.1 The structure and material of the filter equipment are unreasonable Although the filter body is lined with rubber, the inlet and outlet of the brine are not lined with rubber, which causes the equipment body to be short-circuited and severely corroded. At the same time, because the internal liquid collection tank and PE pipe joint are made of 304 material, the salt water is used. In the case of severe chloride ion corrosion and stray current corrosion, the weld seam is cracked, and the joint of the liquid collecting box and the PE pipe are largely detached, and the normal use cannot be maintained. 2.2 The connection method of the filter tube is unreasonable The joint connection mode between the filter tube and the liquid collection tank is sleeved and clamped, and the ordinary stainless steel outer card of the filter tube is not resistant to salt water corrosion, and is easy to fall off, thereby causing the filter tube to fall off more frequently. 2.3 Filter tube selection is not reasonable PE pipe has certain defects in brine filtration. Because some particles are easy to enter the inner wall of the pipe during filtration, it can not be effectively blown out during backwashing, causing clogging, which greatly reduces the effective area of ​​the filter tube, and shortens the service period. The number of washes was backwashed once every 24 hours, and was reduced to every 6-8 hours. The reliability of the equipment can be reduced, and the labor intensity of the operator is also increased. 2.4 Unreasonable operating temperature Due to the defects in the process, the 60 ° C fine brine was preheated to 75 ° C through a hydrogen-salt heat exchanger, and then entered into a secondary filtration device. The PE tube showed accelerated aging and brittleness at a salt water temperature of 75 °C. In November 1999, most of the PE pipes of the two filters were found to be aging, and the brittle fractures were severely degraded. By March 2000, all the PE pipes were almost all aging and could not be used normally. 2.5 Poor reliability of pneumatic switchgear The filter uses a pneumatic switch to open the bottom manhole cover during backwashing. However, the pneumatic quick opening device at the bottom has poor reliability, and the manhole cover is often not opened during use, and the sealing of the manhole cover after the backwashing is not strict, and leakage is prone to occur. 3 Take measures In order to improve the quality of the brine, reduce the tank voltage, and improve the current efficiency, we modified the three brine filters. 3.1 Improve the structure and material of the filter After the short circuit of the filter is completely replaced, the equipment is fully lined with PE, the internal stainless steel liquid collecting tank is removed, and the rubber-lined structure is used instead. The flower board is lining rubber after drilling with 40 mm steel plate. Due to the change of the filter structure, the original liquid outlet is changed from the side to the top, and the pipe is rearranged. After improvement, the equipment not only resists the corrosion of salt water, but also solves the problem that the original joint is easy to fall off and the brine is bypassed, and the quality of the brine is not guaranteed. 3.2 Improve the connection method of the filter tube The fixing joint is used to connect with the flower plate hole, and the joint of the joint and the filter tube adopts a thread heat-tightening method, and the material of the fixed joint is changed from stainless steel to polypropylene. Through the thorough improvement of the connection method, the connection of the filter tube is very reliable, and no drop has been seen so far. 3.3 Improve the filter tube For some particles easy to enter the inner wall of the filter tube, causing tube plugging problem, we replace all the original aged and used PE tube, according to the actual, the original specification is Φ31x20 PE tube, the average aperture 31-38μm improved to Φ38 x 20 The PE tube has an average pore size of 39 to 45 μm. After the pore size of the filter tube is increased, the problem of tube plugging is solved, and the backwashing period is prolonged. The number of backwashing of the filter is extended to one backwash every 24 hours, and the labor intensity of the operator is greatly reduced. Increasing the wall thickness of the PE pipe not only improves the strength of the filter tube, but also compensates for the lack of the filter tube hole. 3.4 Renovate the process and reduce the operating temperature The use temperature of the PE pipe should be controlled below 60 °C. In November 1999, we modified the process. After the transformation, the brine section was transported to the advanced secondary brine filtration device of the electrolyzed brine, and then preheated through the hydrogen-salt heat exchanger and the steam brine heat exchanger to enter the electrolysis cell. In this way, the temperature of the refined brine entering the secondary brine filter is reduced from the original 75 ° C to about 60 ° C, which greatly prolongs the service life of the PE pipe and stabilizes the long cycle of the filter. See Figure 10 3.5 Improve the switching device to improve reliability Remove the pneumatic quick-opening device with poor reliability, change the movable manhole at the bottom of the filter to a fixed manhole, and add a drain port of Dg200 at the manhole, and control with a manual butterfly valve. It is very convenient when backwashing, and solves the problem that the original bottom of the filter is easy to leak. 4 use and improve the effect By using and improving the brine secondary filter, the quality of the brine is improved and the current efficiency is improved. In November 1998, after the overhaul of our factory, the filter was used. The current efficiency increased significantly. The current efficiency in 1999 was 1.75% higher than that in 1998, and the current efficiency per month was greater than 92.7 %. November 1999 The improved three secondary filters after the overhaul have produced significant benefits. In 2000, the current efficiency of the electrolytic cell increased by 0.23% compared with 1999. Now three filters are working well and there is no problem with the PE filter. 1 - 3 indicates a very acidic substance Pdg Test,Ovulation Testing,Ovulation Test Kit,Ovulation Rapid Test Kit Changchun LYZ Technology Co., Ltd , https://www.lyzinstruments.com
4 - 6 indicates an acidic substance
7 indicates neutral
8 - 11 indicates alkalinity
12 - 14 indicates a very high level of alkalinity
Paper Size:app 45mm x 7mm (L x W)
Weigh:app 3g
a. Drink a fresh green juice every single day.
b. Drink the juice of half lemon squeezed in a glass of warm water first thing in the morning (citrus fruits seem acidic but are actually very alkaline!)
c. Eat a diet full of nutritious and alkaline vegetables and fruits.
d. Stay away from all processed foods and fried foods which are extremely acidic.Avoid refined sugar like the plague, fresh fruits are okay.
e. Drink quality water such as purified water or even better, fresh spring water (tap water usually has fluoride in it and is very toxic to the body, which your dentist may not tell you.)
f. Use natural household cleaning agents such as diluted apple cider vinegar.Eat more plant-based foods and opt for only grass-fed, organic animal products.