Proper understanding and implementation of the main parameters of actual operation are very important for the long-term and stable operation of the ultrafiltration system. The main parameters of actual operation generally include: flow rate, working pressure, gas pressure, concentrated water consumption, recovery ratio and temperature.
A. Flow rate:
The flow rate refers to the angular velocity of the fluidity of the source solution (water supply) on the membrane surface ultrafiltration membrane A key practical operation main parameter. When the flow rate is relatively high, it not only causes the consumption of kinetic energy and excessive gas pressure, but also accelerates the decline of the disintegration performance of Dow reverse osmosis membrane. On the contrary, if the flow rate is small, the thickness of the boundary layer generated by the interceptor on the membrane surface will expand, resulting in the polarization of the concentration value, which not only harms the permeability rate, but also affects the permeability quality. Within the allowable working pressure range, improving the water supply and selecting high flow rate are beneficial to ensuring the performance of hollow chemical fiber Dow reverse osmosis membrane.
B. Working pressure and gas pressure:
When selecting the pressure, in addition to the compressive strength of the membrane and the casing, it is necessary to consider the membrane's compactness and the membrane's ability to withstand environmental pollution. The higher the working pressure, the greater the water permeability, the more components that should be intercepted accumulate on the membrane surface, and the greater the friction resistance, which will cause the loss of the permeability speed. In addition, the particles entering the membrane nanotubes are also easy to block the safe passage. In conclusion, if possible, it is beneficial to select a lower pressure to make full use of membrane performance.
C. Recycling ratio and concentrated water consumption:
In the ultrafiltration system, the recovery ratio and the consumption of extracted water are a pair of factors that restrict each other. Recycling ratio refers to the ratio of water volume to supply volume. In most cases, a smaller recycling ratio can be used for actual operation, and the extraction solution can be discharged and reinjected into the source solution system software. By increasing the amount of repetition, the thickness of the stain layer can be reduced, thus improving the water permeability rate. Sometimes, the energy consumption of the enterprise's water production does not increase.
D. Temperature during operation:
The permeable working capacity of Dow reverse osmosis membrane increases with the increase of temperature, and the viscosity of general solution decreases with the increase of temperature, thus reducing the frictional resistance of fluidity, and correspondingly increasing the permeable speed. In engineering technology, the specific temperature of liquid provided on the spot during work shall be considered. In particular, the temperature adjustment shall be taken into account when the temperature is too low for the change of season.
