The basic principle of the plate and frame filter press is to pressurize the plate and frame group through hydraulic pressure, so that the precipitated sludge is distributed between the filter cloths under the action of pressure. Due to the compression of the plate frame, the sludge does not overflow, while the water in the sludge seeps out of the filter cloth and flows into the return pipe under the action of a high-pressure pump, while the mud cake remains in the cavity. Subsequently, by relieving the pressure and pulling the filter plate, the mud cake falls under the action of gravity, thus realizing the process of solid-liquid separation.
Specifically, the plate and frame filter press is composed of several parts, such as filter plate, filter frame, hydraulic system, filter plate transmission system and electrical system. When working, the plate and frame group is first pressurized by the hydraulic system to form a sealed filter chamber between the filter plate and the filter frame. Then, the suspension to be filtered is introduced into the filter chamber through the feed port, and the solid particles in the suspension are trapped in the filter chamber under the action of the filter cloth to form a filter cake, and the filtrate flows out through the filter cloth and filter frame.
During the filtration process, the filtration speed and the solids content of the filter cake can be controlled by adjusting the pressure of the hydraulic system. When the filtration is completed, the pressure is relieved through the hydraulic system and the filter plate is pulled apart, so that the filter cake is detached from the filter chamber and a filtration cycle is completed. This can then be followed by pressurization and filtration operations for continuous production.
It should be noted that when using the plate and frame filter press, the appropriate filter cloth and filter frame material should be selected according to different material characteristics and filtration requirements, and regular cleaning and maintenance should be carried out to ensure the normal operation of the equipment and the filtration effect.