Standard water production and design water production of mem
Due to the different water quality around the world, and the world is also no unified reverse osmosis membrane element test standard, the membrane component manufacturers in the product quality inspection, testing conditions can only be selected by the membrane element, membrane element manufacturer's standard test conditions. Test conditions for each membrane membrane components manufacturers selected components production test conditions are not exactly the same, manufacturers of the same membrane element production on different series of membrane components selected is not exactly the same, membrane element standard water production for the membrane component manufacturers to measure water production in its standard test conditions.
The amount of water produced by the membrane element is the actual amount of water produced by the designers in the design of the reverse osmosis system. The standard test solution preparation water for reverse osmosis water, which almost without impurities, there is no membrane component is the pollution problem in actual use, in addition to the two stage reverse osmosis water system is the water level of the reverse osmosis system as raw water, other reverse osmosis water system almost all by the general pretreatment of raw water, although the removal of some impurities pretreatment, but under standard test conditions, compared with the water, the water quality is still poor, if still in accordance with the standard design of water production as the production of water, the reverse osmosis membrane elements will soon be contaminated, resulting in damage to membrane components.
In order to avoid this, the film manufacturer provides design guidelines to enable the designers to follow. Design guidelines should be to select different design water production based on different water sources, that surface water containing more pollutants, pollution index SDI value between 3~5, the per unit area yield should be selected to design a low value, water containing pollutants in groundwater than surface water pollutants with less pollution. The SDI index value is low, usually less than 3, so the value per unit area on the design of high water production can be selected, if the water level of the reverse osmosis system as the two stage reverse osmosis water, almost without impurities, the pollution index of SDI is low, generally less than, the unit area of the design water production can be higher than the groundwater numerical selection.
Accordingly, know each in reverse osmosis water production and water production design standards not only on the effective membrane area, water supply, such as SDI value, the number of membrane elements = yield / yield system design assumptions of each pressure vessel with membrane element 6, it can take 6 times, the number of the design of membrane system components should be 198~114. According to this analogy, when groundwater is used as water source, the number of membrane components in this system should be 114~96. When the water production of the first order reverse osmosis system is used as the water of the two level reverse osmosis, the number of membrane components in this system should be 84~54.
The membrane element design guidelines provided by the manufacturer of membrane components is the membrane component manufacturers according to their products and understand its products for many years of practical experiences and summed up, only the membrane component manufacturers recommendations, such as the user in accordance with the design and use of design guidelines, manufacturers will provide 3 years of membrane element production quality guarantee the product. But the design guidelines for the design of water production is only a range, designers should make a decision according to their own experience and actual use of the situation. Due to the groundwater or surface water as the water source of water, the average water flux of the system is too high, will cause the reverse osmosis system damage in a short period of time, and will cause the membrane component manufacturers to provide for its products 3 years warranty failure, so it is not reasonable design.