The siphon principle of the horizontal siphon scraper discharge centrifuge

Abstract: The horizontal siphon scraper discharge centrifuge is a new type of centrifuge. It applies the siphon principle to the filter scraper discharge centrifuge, which greatly enhances the filtration driving force of the centrifuge. Enhanced centrifuge separation is a major breakthrough. The principle of siphon is analyzed in detail in order to realize the localization of this model and replace imported products.

Keywords: siphon centrifuge; siphon principle; suspension; filtration speed

CLC number: TH69 Document identification code: A

The horizontal siphon scraper discharge centrifuge is a machine that uses the centrifugal force generated when the rotating drum drives the materials in the drum to rotate at a high speed to separate two immiscible liquids with different densities and a suspension of solid particles. It is a patented product of German KRAUSS MAFFEI company. It has a series of products after three or four years of development. At present, Germany, France and Japan are all producing and developing in the direction of improving technical parameters, serialization and automation. At present, the demand for this model in my country is relatively large and mainly depends on the introduction. Therefore, it is particularly important to realize its localization.

1 The principle of siphon

Compared with the common scraper centrifuge, the horizontal siphon scraper discharge centrifuge adds a siphon chamber and a siphon device. During filtration, the filtrate flows into the siphon chamber through the filter cloth through the side holes on the drum, and the filtrate in the siphon chamber is drawn out by a fixed skimming siphon. The outside of the skimming siphon is connected with a hydraulic mechanism, and the liquid level in the siphon chamber is controlled by hydraulically adjusting the position of the skimming siphon. Suppose the thickness of the filter residue layer is H' and the pressure difference between the two sides of the filter medium is Δp, then the filtration speed v=k'ΔpH' (where k' is the proportionality constant). That is, the filtration speed v is proportional to the pressure difference Δp on both sides of the filter medium, and inversely proportional to the thickness H' of the filter residue layer. The filter siphon scraper centrifuge adopts the siphon principle on the other side of the filter medium to increase the pressure difference on both sides of the filter medium, thereby increasing the filtration speed v. Therefore, the advantages of the siphon scraper centrifuge compared with the ordinary filter scraper centrifuge are significant. The filtration of the suspension is divided into two successive stages: the liquid level of the suspension drops to the surface of the filter residue layer and the filtrate continues to fall in the filter residue layer. The filtrate continuously passes through the filter residue layers with different resistances, namely the normal filter residue layer and the filter residue layer compacted by the scraper (hard residue layer). The filtration time of different stages must be calculated separately, and the total resistance of different filter residue layers should be considered at the same time. Under the same conditions, the filtration speed of the siphon scraper centrifuge is faster than that of the ordinary scraper centrifuge, and the speed of filtration, drying and washing can be easily adjusted according to the different requirements of each operation stage.