How does a fully automatic filter press work?

 The driving force for filtration of a fully automatic filter press is the pressure difference on both sides of the filter medium, which is called the working pressure. The filtration process of the fully automatic filter press is as follows: the suspension is introduced into each filter frame from the feed hole, and the filtrate is pushed through the filter media layer under pressure and flows to the filter surface of the filter plate. After being concentrated in the grooves of the filter surface, the filtrate is discharged from the hole discharged from the machine.

Fully automatic filter presses usually use filter cloth as the filter medium. Other filter media can also be used when there are special requirements. For example, the accurate filtration process in the petroleum industry uses filter paper as the filter medium. In the early stage of the filtration process, small solid particles in the suspension often pass through the filter cloth layer, so the filtrate is not very clear, but larger particles are quickly intercepted by the filter cloth fibers, or stuck in the channels of the fiber gaps, causing the The gap through which the filtrate passes quickly becomes smaller. This process is called bridging phenomenon in filtration theory.

The fully automatic filter press is composed of two main components: the filter shell and the filter bag. It is a filtration equipment with a new structure, small size, simple operation, energy saving and high efficiency. Let’s take you through the working process of a fully automatic filter press.

The working process of the fully automatic filter press: The filter press has a simple structure, reliable operation and strong adaptability. It generally works according to the following process.
(1) Press the filter plate tightly. Operate the hydraulic system to move the tail plate toward the head plate and tighten all filter plates between the head plate and the tail plate. As a result, a hollow sealed filter chamber is formed between adjacent filter plates.
(2) Press filtration process. The feed pump transports the mud from the feed hole of the tail plate to the filter chamber. When the filter chamber is filled with mud, the filter press process begins, and the mud is separated from solid and liquid with the help of the pressure of the feed pump. In the early stage of filter press, the thickness of the mud cake in the filter chamber is not large, the resistance of the filter cake is small, and the dehydration speed is fast. Usually, a low-lift, large-flow pump is used at this time. As the thickness of the filter cake increases and the resistance increases, the filter press speed decreases. At this time, a pump with high lift and small flow rate should be used. The time required for the filter press process is determined according to the filtration characteristics and process requirements of the mud. When the specified filter press time is reached, the feeding is stopped and the filter press process is completed.
(3) Loosen the filter plate. Operate the hydraulic system to return the head plate to its original position.
(4) Unload the filter plate. The transmission chain on the transmission and opening device successively pulls the filter plates apart, and the filter cake falls off by its own weight and is transported away by the lower conveyor.

During the working process of the fully automatic filter press, the filter slurry is driven into the pressure vessel through the feed pump and enters the filter bag for filtration. During filtration, since the diameter of the filter bag is larger than the cage frame, the filter bag is close to the cage frame during filtration. The intercepted solid particles adhere to the surface of the filter bag to form a filter cake, and the filtrate filtered through the filter bag is discharged from the shell.

When the filter cake layer adhering to the surface of the filter bag reaches the thickness during operation, the filtration is stopped, the residual liquid is discharged, and the compressed air is used to back-blow the filter bag to remove the residue. During backflush, the filter bag expands and returns to its original diameter, and the filter cake on the outer wall of the filter bag cracks into small, non-connected pieces. The backflush makes the filter bag continuously vibrate, and the small pieces of filter cake continue to fall, falling off cleanly and quickly. After unloading the filter cake, the filter bag is rewashed with washing water to regenerate the filter bag.