The adsorbent absorbed by the pre-absorbed filtrate and the diluted purified water or filter slurry are mixed into a suspension in a feeding bucket, and after the concentration of the liquid to be absorbed reaches the requirement, the filter slurry is separated. Enter, proceed in advance. The direct medium of the coating (the role is generally applicable to the expansion filter screen. The thickness of the millimeter layer is generally 3-80. In the actual production of the filter screen, the cake can also be continuously cut (such as a vacuum drum filter cake machine), which can be new The filter bed is stable and stable.
(2) Percolation:
The precipitation filtration is carried out in two steps: pre-coating and adding: the thickness of the pre-coating is generally 2-3 mm. The main function is to protect the filter material from absorbing pollution, and at the same time transform it into a polymer coating when it is added to the filter. The pre-coating coating is generally 2-3 mm. The thickness and structure are important in the whole process. According to the nature of the filter material (viscosity, particle and content, compressible filterability of particles, etc.), the user can use the following procedures:
(1) Pre-coating
The pre-coating is formed by the bridging effect of filter aid filtering on the medium. Yes: Prevent the filter medium (the liquid to be filtered) from the particles in the filter; the filtrate can be obtained at the beginning of the filtration; the filter medium is easy to lock. When pre-coating, the specific filter aid and clear liquid (or disinfection water) are proportioned into a 5-10% (mass ratio) suspension in the pre-coating tank, and a good and stable pre-coating is formed on the filter medium through the circulation pump. coating. The pre-coating thickness of the filter press is about 2-4MM thick (the pre-coating filter aid dosage is 700-1000G/m²). The double air filter requires a pre-coating 8-15CM. Obvious filtration requirements, with low-viscosity fluid (about 1CP), the typical pre-coating flow rate is about 40L/m², and the low-viscosity fluid pre-coating flow rate is reduced accordingly.
(2) After adding filter aid to filter and pre-coating, after the filter powder enters the filter, it is necessary to add a filter aid of 0.1-2.0% by weight of the slurry. In the process of filtration, the filter aid and the impurity particles in the filter slurry are added to the filter press correspondingly. The addition amount maintains the amount and compressibility of the formed particles. The impurity with high compression rate, the filter aid addition amount is corresponding The increase. The addition of the filter should be formed when the filter pressure reaches the pressure. The filter screen basically filled with the filter screen allows the completion of the suction filter space. At this point in the filtration cycle, the filter screen enters the adsorption stage.
(3) Add filtering directly:
The filter aid and the solids in the filter slurry are co-deposited on the original pre-layer or filter layer to form a new filter layer, so that the filter can maintain a stable state. Filtration speed. At this time, the particle size of Wu Jia’s filter aid is only determined by the characteristics of the shape in the filter slurry, and is not affected by the formation of the filter.
Post time: Sep-26-2021