Factors affecting the filtration of water treatment equipment

1 , temperature

When filtering, the temperature of the suspension is low, the viscosity is high, and the filtration speed is slow. The viscosity of the liquid is an exponential function of temperature, which decreases with the increase of temperature. The temperature rise is a simple and effective measure to reduce the viscosity, but the temperature is too high. It is easy to oxidize the oil, and the filtration temperature of the oil is generally not more than 70 degrees.

2 , operating pressure

Most of the impurities in the oil are incompressible impurities, the operating pressure is strong, and the filtration rate is also large. If the solid matter suspended in the oil is composed of a colloidal substance, the void in the filter cake becomes smaller as the pressure increases, and the filtration resistance gradually Increase, the filtration speed drops rapidly, so the pressure must be determined according to different situations.

3 , suspension concentration

The concentration is large and the amount of filter residue is large, so that the effective filtration time in each operation cycle of the batch production is shortened correspondingly, which affects the output. For the operation of the continuous vacuum filter, the filter cake generated when the concentration is large is relatively uniform, and is easy to clean in time. Has little effect on production.

4 , filter media and filter aids

The choice of filter media affects the degree of clarification of the filtered grease, and whether the unloading cake is smooth. The filter media used in the grease industry is mostly woven media. Commonly used 20 yarns of 5-8 strands of canvas, twill plain white cloth and other cotton fabrics. Commonly used 130#, 240#, 260#, 261# polyester filter cloth and 828# dimension nylon filter cloth and other chemical fiber products. The number of warp and weft strands is used for crude oil filtration, and the number of strands is small for essential oil filtration. For the filtration, a layer of white cloth or flannel is required on the outside of the coarse filter cloth. In addition, a stainless steel wire woven filter screen is used, and a 30-40 hole/cm filter is used for the oil filtration, 140-180 holes/cm filter. The net is used for decolorizing oil filtration.

For suspensions containing more colloidal particles, the addition of filter aids can effectively increase the filtration rate. Especially for some process limitations, it is not possible to use a suspension system that increases the temperature filtration. The application of filter aids is of great significance. When oil is used to prepare edible phospholipids, diatomaceous earth is added as a filter aid; in dewaxing, it must be filtered at a lower temperature, and the effect of the filter aid is more obvious.