What Is The Screening Process Of Water Treatment?

The quality of raw water is very complicated, and a series of filtration steps are required to obtain the required water quality, so the filtration process of water treatment is necessary.

Filtration is an operation that uses a certain porous medium to separate the suspension. When working, under the action of external force, the liquid in the suspension flows out through the pores of the medium, and the solid particles are intercepted, thereby achieving separation. Generally, the suspension to be filtered is called the filter slurry; the porous medium used is called the filter medium; the liquid passing through the pores of the medium is called the filtrate; the retained solid is called the filter cake or filter residue.

The driving force of the filtration operation is the pressure difference between the upstream and downstream sides of the filter medium.

There are several ways to generate the pressure difference:

　　①Using the pressure head of the filter pulp itself;

　　②Pressure on the surface of the filter slurry;

　　③Pull a vacuum on the downstream side of the filter medium；

      ④Using inertial centrifugal force. 

The filtering operation can be divided into two categories according to the principle of action:

① The mesh size of the sieve filter filter medium is smaller than the diameter of the solid particles, and the solid particles are removed from the suspension by the sieve analysis.

In the initial stage of filtration, the fine particles flow out and the filtrate is relatively turbid. With the formation and thickening of the cake layer, the filtrate gradually becomes clear. Due to the gradual blockage of the sieve holes, the filtration rate is in a decreasing trend. During the filtration process, when the filter cake layer is formed, the sieving effect is produced by the cake layer, and the filter medium loses the sieving effect and only plays the role of supporting the cake layer, which is called cake layer filtration.

②Adsorption filtration (deep bed filtration): The mesh of the filter medium is larger than the diameter of the solid particles, and the solid particles are absorbed by the surface of the medium after entering the pores of the filter medium.

In actual production, sieving and adsorption work simultaneously, and the adsorption filter medium retains larger particles; the sieving filter medium cake layer can adsorb smaller particles.

About us

Zhangjiagang Alps Machine Co.,Ltd is located at the new port city-Zhangjiagang, it was founded at 2011 and started with beverage filling and packing machinery. Our company covers an area of 15,000m2 and has standard workshop of 12,000m2. We have over 20 engineers in researching department and over 60 staff for machine manufacturing. We are a leading enterprise in research and production of beverage filling and packing machines. We are not only a machine manufacturer, we can also supply turnkey project according to customers’ request, including workshop design, machine layout design, water, gas, electic cable layout design, label and bottle design. Our mission is to ensure customers’ plant properly working and help customers win their market.

Our main products including: water treatment system, mineral water filling machine, labeling machine, packing machine, CSD production line, juice production line, 5 gallon water production line, PET bottle blowing machine, injection molding machine and so on.

We will carry on to meet the demands of our customers and seek for deeper cooperation with them.