Filter principle of belt filter

January 10, 2024

Filtration is a process in the industry that refers to the separation of solids by a medium to achieve solid-liquid separation, which is referred to as filtration.

Filter media commonly used in the industry: fabric media, granular media, porous media ceramic media. Use fabric media in coal preparation plants. The vacuum filtration equipment of the coal preparation plant can be divided into two categories: disc vacuum filtration equipment and cylindrical vacuum filtration equipment. It is mainly used for filtering flotation clean coal and also for filtering slime or flotation tail coal.

(1) Principle of belt filter

Filtration is a process in which solid particles suspended in a liquid or gas are separated. The basic principle: under the action of pressure difference, the liquid (or gas) in the suspension passes through the permeable medium (filter medium), and the solid particles are trapped by the medium, thereby separating the liquid and the solid.

1) Two conditions for implementing filtering:

1 having the equipment necessary to achieve the separation process;

2 Maintain a certain pressure difference (pushing force) on both sides of the filter medium.

2) Commonly used filtration methods can be divided into gravity filtration, vacuum filtration, pressure filtration and centrifugal filtration.

The gravitational pressure difference is formed by the height of the slurry column; the driving force for vacuum filtration is a vacuum source.

3) Filtration has characteristics: In essence, filtration is the flow of multiphase fluid through a porous medium.

1 The flow of fluid through the porous medium belongs to very slow flow, ie, seepage flow. There are two influencing factors, one is the macroscopic fluid mechanics factor, and the other is the microphysical and chemical factors.

2 The solid particles in the suspension are continuously deposited in the pores of the medium or on the surface of the medium, so that the filtration resistance increases during the filtration process.

4) Classification of filtration: divided into two categories: filter cake filtration and depth filtration, filter cake filtration using surface belt filter, and deep filtration, solid particles are trapped in the pores inside the medium.

5) Filter cake filtration and depth filtration:

1 The filter cake filters a suspension of generally higher concentration, often at a volume concentration above 1%. If a flocculant is added to the slurry, some low concentration suspensions can also be filtered using a filter cake.

2Deep filtration mostly separates fine solid particles from a very dilute suspension, so it is usually used for liquid purification. In the case of similar efficiencies, the initial pressure of the depth filter is generally higher than that of the surface filter , and as the collected particles increase, the pressure drop will gradually increase.

6) The purpose of filtration is to recover a valuable solid phase, or to obtain a valuable liquid phase; or both, or both, as waste.

1. Infiltration process of incompressible filter cake

(1) Filtration process of incompressible filter cake

Incompressible filter cake: When filtering, the liquid flowing through the filter cake is transferred to the surface of the solid particles by a drag force, which is transmitted forward through the point contact particles and gradually accumulates in the flow direction. If the filter cake structure does not shift from each other under the accumulated drag stress, and the porosity of the filter cake does not change, the filter cake is referred to as an incompressible filter cake.

A compressible filter cake industrial reasons: ① the individual particles in the slurry rarely actually present, but often there are different degrees of agglomeration, agglomeration interface drag bear the stress deformation cake liquid; ② -10μm particles almost all have salt film on the surface, the salt film will deform under the action of fluid; 3 the aggregates or flocs formed by solid particles under the action of coagulant or flocculant have only small shear resistance, in liquid It is easy to produce deformation under the action.

Uv Curing Screen Protector,Uv Curing Film Sheets,UV Cured Screen Protector,UV Screen Protector,UV Light Screen Protector

前

お問い合わせ

Author:

Ms. eleven

Eメール:

magic@magicmax.cc

Phone/WhatsApp:

+8613538497137

人気商品

企業ニュース