Filter press equipment is an important device used for solid-liquid separation in the industrial field. Its design is exquisite, consisting of key components such as filter plates, filter frames, filter cloths, and pressing devices. Different types of filter press equipment, such as plate-and-frame, chamber, and membrane types, have different focuses in structure and function, and can be selected according to the characteristics of the materials to be processed and production needs. It is widely used in chemical industry, mining, environmental protection and other industries, providing efficient solutions for material purification, separation and dehydration. Here, Yuwei Filtration will explore how does a filter press work.
The working principle of the filter press is essentially to force solid-liquid separation through mechanical pressure: in a sealed chamber, the liquid in the high-pressure suspension passes through the filter cloth or filter screen to become filtrate, while the solid particles are intercepted to form filter cakes; as the filter cake thickens, it itself is transformed into a precision filter layer to improve separation accuracy. Active interventions such as membrane pressing or gas back-blowing can further squeeze out bound water, and finally obtain high-dryness filter cakes and clear filtrate.
The filter plates are tightly pressed together by the pressing device to form multiple sealed filter chambers. The filter cloth between the filter plates not only serves as a filter medium but also ensures the tightness of the filter chambers, providing a closed space for subsequent separation.
The suspension to be filtered is pressed into each filter chamber through the feeding channel by the pump, filling the filter chambers with materials and forming a certain pressure to ensure full contact between the liquid and the filter cloth.
Driven by the pressure difference, the liquid in the suspension passes through the filter cloth and is discharged through the liquid guide structure of the filter plate to become filtrate; solid particles are intercepted by the filter cloth and gradually accumulate in the filter chamber to form a filter cake until the filtration end point is reached.
After filtration, the pressing device is released, the filter plates are separated, and the filter cake is separated from the filter chamber by its own gravity or auxiliary force.
After cleaning the residual impurities on the filter cloth, the filter plates are re-closed and pressed, and the equipment returns to its initial state, ready for the next filtration cycle.
The plate and frame filter press dominates in the separation of materials with high solid content, high viscosity, high pressure, and coarse particles. Although its degree of automation is slightly low, it remains an irreplaceable "industrial separation heavyweight" in fields with high requirements for filter cake quality and processing difficulty. The frame filter press working principle is as follows:
Filter plates and filter frames are arranged alternately and pressed together by a pressing device to form sealed filter chambers, with filter cloth clamped between the filter plates and filter frames.
The suspension enters the filter chamber through the central feeding port of the filter frame and diffuses around under pressure.
The liquid passes through the filter cloth and is discharged through the liquid guide grooves of the filter plate to become filtrate; solid particles are intercepted and form filter cakes in the filter frame.
After the filter frame is filled with filter cakes, the pressing device is released, the filter plates and filter frames are separated, and the filter cakes are taken out to complete a cycle.
