The MBR membrane process, which is a high-concentration wastewater treatment process, is now more and more widely used to attract attention for its stable sewage treatment capacity. However, its huge maintenance volume also causes headaches for many users. Therefore, to minimize the maintenance work during use Strength, in the design phase you need to pay attention to the following questions;
First, the wastewater is not suitable for MBR membrane method
MBR is not a panacea. It belongs to a microfiltration membrane and is defined by the particle size that can be passed; therefore, the clogging problem is key to it. Some are prone to fouling and contain more oil-based and viscous substances Wastewater, it is recommended not to use MBR membrane method;
The types of wastewater not suitable for MBR are: emulsion / slurry / quench / coolant waste, surfactant waste, petroleum waste, lipid waste (except for pretreatment);
Second, the MBR brand and the corresponding number of OK
MBR film decided to use, then the next step is to decide what brand, at present, the quality of imported MBR film and the gap between domestic or very large, although the number of domestic film by increasing the number of membrane, reducing the amount of flux design can also meet the needs, However, the corresponding problems follow one after another.
From the price, the imported film is about 3 to 5 times the domestic film, the price is acceptable under the premise, as much as possible into the film imports, Mitsubishi and Seiko diaphragm are good, of course, made in the film to ensure adequate design margin The premise is still possible, it is important that designers should make in-depth technical communication with suppliers, design flux, the general domestic membrane manufacturers factory design flux has left enough margin, but designers still have to Increase the margin, personally think that an increase of more than 50%, such as I have designed a small amount of waste water, MBR use of domestic brands, but the design MBR dosage is 10 times the standard amount, to now 2 years without cleaning, has been in normal use , Effluent COD maintained below 30mg / L;
In addition, the recent flat anti-fouling performance of flat film is superior to the filamentous membrane; flat membrane is divided into PVDF and PTFE materials, PTFE strongest anti-pollution performance, currently only imported products, the best performance in Japan; membrane Design flux reference to the data provided by the supplier;
Third, MBR membrane module design
1, the membrane assembled together to form a membrane module, with particular attention is that the distance between the membrane and the diaphragm should be large enough, the effective distance to be greater than 100mm (axis distance greater than 140mm), if the membrane itself membrane density Large, so the effective spacing should be properly relaxed, the purpose of doing so is to maintain a smooth flow of air to reach the top of the membrane filament, but also reduce the film between the wire knot and retentate, to reduce the cleaning frequency of the membrane module;
Flat film spacing as long as 60 ~ 80mm on it; Too much space lead to occupy too much space;
2, the film can be installed horizontally and vertically, depending on the installation space; horizontal loading, the film wire to maintain micro-sagging, drooping amplitude maintained at 10mm, it can be said that in ensuring the film under tension on the premise , Try to straight, so there will not be too much debris between the film and membrane silk; recommended vertical installation;
3, can not do a great deal of membrane components, because too large membrane components, the installation density will be large, the same amount of mixing air but it is insufficient, but also in the accumulation of a lot of film on the package, You need to spray the diaphragm, with high pressure water gun or tap water, the installation of too dense will make it difficult for you to rushed to the inner diaphragm, it is recommended not to exceed a single membrane module throughput 1.5m3 / hr;
Fourth, MBR aeration device design points
1, the aeration device can be fixed in the bottom of the pool (need to do the film components bearing bracket and membrane components slide into the rail), can also be done with the membrane components, each have their advantages and disadvantages, the location of aeration pipe to do careful consideration, The use of DN20 perforation pipe, each diaphragm corresponds to a perforated pipe gap, perforation size Φ2.0mm, perforation spacing 100mm, the adjacent two pipe perforation location interlaced, single vertical row of holes to do a lot of double row, oblique Under the practice, personally think it is not desirable, settlement of the sludge will not be blocked on the orifice.
2, the size of the aeration to make a rough estimate, according to the empirical figures, according to the fizhe ratio 24: 1 (conventional pool depth 3.5m), fan exhaust head selection than the highest level 0.01Mpa; fan outlet set deflated Valve, exhaust pipe full diameter can remove 70% of the air can be installed on the vent muffler, this device is used to control the biochemical tank DO value and to protect the fan;
3, each membrane aeration unit is set up a separate control valve, while the biochemical tank oxygenation aeration to do another separate control valve, with microporous aeration aeration device, to ensure flexible adjustment of mixing air volume and charge Oxygen air volume;
4, MBR pool DO control best between 2.5 to 5, the normal level of about 3ppm, the level of different levels, DO will change, should not exceed 5.0ppm for a long time
Five, MBR suction pump design points
1, under the conditions of conditions, as far as possible with a pump for each membrane module, so easy to observe and determine the status of each membrane module (pressure and flux), but a total of more than one membrane module can be, in each membrane Component suction pipe mounted on the flow meter;
2, the suction pump installed below the liquid level, the lower the better, in the normal state of the membrane module, by siphon can also be the water, if the MBR pool is an underground pool, then do the underground room to ensure that the suction pump can have Enough suction; MBR below the main parameter is the transmembrane pressure, the brand is slightly different, generally not higher than 0.03Mpa, where the transmembrane pressure differential is not necessarily equal to the vacuum gauge reading, but also depends on the pump into If the vacuum gauge reading 0.03pa, biochemical pool liquid level than the pump inlet 1m, then the transmembrane pressure differential at this time 0.04Mpa; if the pump installation location is higher than the biochemical Tank liquid level 1m, then the transmembrane pressure difference at this time is only 0.02Mpa, the formula is: Transmembrane pressure difference = vacuum gauge reading (plus) + (biochemical pool level - suction pump inlet height)
3, the suction pump outlet pipe must be installed with a transparent flow meter and sampling valve, the transparent flow meter can visually see the water quality status, each flow meter in front of or behind the control valve, used to adjust the membrane module out Water quantity
4, electrical control: General settings MBR suction pump running for 13min running, 2min stop, can effectively reduce the frequency of blockage, the specific start-stop time to seek the advice of the manufacturer, the pressure gauge in the electrical contact pressure limit, can stop the pump and alarm ; Suction pump to be able to linkage with the fan, fan in the stop state, suction
Oxygen Sensor For Peugeot,Peugeot Oxygen Sensor,Peugeot Lambda Sensor,Peugeot O2 Sensor
RUIAN XIANGTAI AUTOMOTIVE PARTS CO ., LTD , https://www.raxiangtai.com