Differences Between Plate and Frame Filter Press and Membrane Filter Press

As the demand for solid-liquid separation grows across sectors—such as industrial wastewater treatment, mine tailings dewatering, chemical filtration, and food processing—plate and frame filter presses and membrane filter presses have emerged as essential filtration machine. Many purchasers often face a dilemma when selecting the right model: What exactly are the differences between the two, and which one is better suited to their specific operational requirements? As a professional filter press manufacturer, we provide a detailed analysis below.

Structural Differences

A plate and frame filter press consists of an alternating arrangement of solid filter plates and recessed (frame-type) filter plates. When clamped together, these plates form filtration chambers, with filter cloth positioned between them. This design is relatively simple and easy to maintain, making it suitable for a wide range of standard solid-liquid separation applications.

A membrane filter press, by contrast, utilizes an alternating arrangement of solid filter plates and membrane filter plates. The membrane plates contain an internal, deformable chamber; once the initial filtration phase is complete, water or compressed air is introduced to expand the membrane, applying secondary mechanical squeezing to the filter cake. Compared to standard plate-and-frame filter presses, membrane filter presses offer an additional dewatering stage, making them ideal for processes that require a lower moisture content in the final filter cake.

Filtration Methods and Filter Cloth Design

In a plate and frame filter press, the process relies primarily on the pressure provided by the feed pump to force liquid through the filter cloth, while solid particles accumulate to form a filter cake. Once the filtration chambers are full, the cycle concludes, and the filter cake must be discharged before the next cycle begins.

A membrane filter press also begins with a standard filtration phase, but it adds a membrane squeezing step after the initial cake has formed, further extracting moisture from within the cake. The filter cloth is typically designed as a wrap-around style tailored to the specific membrane plates, with the exact installation method depending on the plate structure. For both types of machine, the filter cloth must be carefully selected based on particle size, slurry characteristics, and required filtration precision to minimize clogging and ensure the quality of the filtrate.

Filter Cake Moisture Content and Dewatering Performance

Plate and frame filter presses are well-suited for projects with moderate requirements for filter cake dryness, materials with favorable filtration characteristics, and limited budgets. Their simple design allows for relatively easy maintenance, effectively controlling both machine procurement and operational costs while meeting process requirements.

For enterprises aiming to lower sludge moisture content, reduce the volume of solid waste for transport, or recover a greater volume of liquid, membrane filter presses typically offer a distinct advantage. The secondary squeezing stage further reduces the moisture content of the filter cake; the actual outcome depends on factors such as material properties, filter cake compressibility, filtration pressure, and squeezing duration. Under appropriate operating conditions, membrane filter presses can significantly lower downstream costs related to transportation, drying, and disposal.

Selecting the Right Filter Press for Enhanced Solid-Liquid Separation Efficiency

Both plate and frame and membrane filter presses have their own unique strengths; there is no single "best" solution for every operational scenario. If your production process demands extremely low moisture content in the filter cake, involves highly viscous materials, or requires shorter pressing cycles, a membrane filter press is an ideal choice for increasing production capacity and product value. Conversely, if your application involves a limited budget, standard materials, and less stringent moisture content requirements, a plate and frame filter press—with its simpler structure and lower initial investment—offers a more cost-effective solution. As a professional filter press manufacturer, Quanhong Filtration possesses extensive experience in international exports and can provide customized solid-liquid separation solutions tailored to the specific characteristics of your materials. Please feel free to contact us for a detailed quotation.