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Filter Operation Essentials
Jun 09, 2017

Filtration is a general term for a large class of unit operations. Through the special device to purify the fluid purification process, a lot of filtration, the use of the system is also very wide, solid - liquid, solid - gas, large particles, small particles are common.

(Or gases) through the media, solid particles and other substances in the suspension (or containing solid particles of hot gas) under the action of impetus or other external force, Filter so that the solid and other substances are mixed with the liquid (or gas ) Separate operation.

First, the purpose of filtration

: First, the insoluble solution in the solution to get the solution, the second is to remove the solvent (or solution) to get the crystal.

Second, the commonly used filter 1, atmospheric filtration: operating essentials: a paste, two low, three by. With the filter filter of ordinary funnel filter, the filtrate by its own gravity through the filter paper flow, to achieve separation. Will filter four fold, into the funnel, Filter the edge of the funnel than the edge slightly lower, wetting filter paper. Carefully pour the liquid into the funnel with a glass rod, and the liquid level should be lower than the edge of the filter paper.

 If the sediment particles are small, Filter the solution can be left to settle the sediment, and then carefully put the supernatant into the funnel,

Finally, the part of the precipitation into the funnel. This will speed up the filtering.

Decontamination filtration (suction filtration) is filtered by a Buchner funnel or a glass sand core funnel mounted on a filter flask with filter paper. Filter Filter The suction pipe is connected to the suction device and the filter is carried out under reduced pressure.

Outside the role of pressure through the filter paper or sand core flow, to achieve separation. The decompression filter consists of a porcelain buzzer, a filter bottle, a safety bottle and a suction pump (Figure 2).

Filter before the election than the Bucket funnel slightly smaller diameter of the circular filter paper tile in the bottom of the funnel, wet with a solvent, open the suction device, so that the filter paper close to the bottom of the funnel. When filtering, carefully pour the mixture to be filtered into the funnel, so that the solid evenly distributed throughout the filter paper surface, has been pumping until almost no liquid filter so far. As far as possible in addition to net liquid, can be

Squeeze the cake with a glass stopper. When the filter is stopped, turn the cock on the safety bottle back to normal pressure, and then close the pump. Wash the filter cake in the funnel: the filter cake as possible to dry, dry, open the safety bottle on the cocks to restore often

Pressure. A small amount of solvent evenly sprinkled on the cake, Filter so that the solvent can just cover the filter cake. Standing for a moment, so that the solvent permeates the filter cake,

To be a filtrate from the lower end of the funnel, re-pumping, then try to dry the filter cake, dry. This is repeated several times

Wash the filter cake. The advantage of reduced pressure filtration is the speed of filtration and washing, the liquid and solid separation is complete, the filtered solids are easy to dry.

Filter with a copper hot water funnel with a glass funnel. Hot water funnel between the inner and outer walls of the cavity can be filled with water, when used in the shell branch pipe heating, the sandwich in the water can heat the funnel insulation, so that the filter in the hot water insulation

Under the next. When filtering the hot saturated solution with a conical glass funnel (do not use a glass rod to drain or tap the glass funnel neck against the inner wall of the beaker), Filter often resulting in cooling on a glass rod, funnel or its neck Precipitation of crystals makes filtration difficult.