Filter Press 101

Since filter presses are useful across a wide range of industries and applications—chemical processing, lime softening, produced water treatment, concrete wastewater treatment, metal finishing, laundry and car wash wastewater recycling, and many more—it is important to know a little more about the basics. Product knowledge means that the right filter press will be utilized for the right application.

What Is a Filter Press?

To put it simply, filter presses use pressure filtration to separate solids from liquids in industrial and municipal applications. Each filter press is designed based on the amount and nature of the slurry that needs to be dewatered. These factors then affect the size of the press and filter plates, the number of plates needed, the types of plates and filter cloths being utilized, and the materials of construction – that is, the type of manifold, coating, etc.

The cycle time needed to dewater the slurry, or the semi-liquid mixture with fine particles, can be anywhere from a few minutes to more than six hours, depending on the process and application. Generally, a slurry is pumped into the filter press and dewatered under pressure. Similar to a kitchen strainer, filter cloths serve to trap the particles from the slurry as the mixture moves through the press. The result is two separate components: filtered liquid, typically water (filtrate) and a filter cake.

The water can be recycled, helping to preserve a limited resource, and the cake discharge needs to be disposed of properly, depending on the components and consistency of the waste that is in the cake. In some cases, the cake is actually the product.

The Four Main Components of a Filter Press

Frame: The steel frame acts as a clamping device for the filter plates. (A)

Filter Plates: A filter cake forms in the chambers between the filter plates. (B)

Manifold: Our standard manifold consists of piping and valves which control the slurry inlet and connect the four corner filtrate discharge ports into a common discharge pipe. (C)

Filter Cloth: A cloth filter that is attached to both sides of a filter plate. Solids build up on the cloth to form a filter cake, separating liquids from solids.

M.W. Watermark - The Main Components of a Filter Press

How Does a Filter Press Work?

Step 1: Slurry is pumped into the filter press. The solids are distributed evenly during the feed (fill) cycle.
Slurry is pumped into the filter press. The solids are distributed evenly during the feed (fill) cycle.
Step 2: Solids begin to build on the filter cloth, trapping the ensuing particles and building a filter cake. The filter cake acts as a depth filter for solid/liquid separation. Filtrate exits the plates through the corner ports into the manifold.

Solids begin to build on the filter cloth, trapping the ensuing particles and building a filter cake. The filter cake acts as a depth filter for solid/liquid separation. Filtrate exits the plates through the corner ports into the manifold.
Step 3: The filtrate exits the press through the filtrate outlet. As the filter press feed pump builds pressure, the solids build within the chambers until they are completely full of solids, forming a filter cake.
The filtrate exits the press through the filtrate outlet. As the filter press feed pump builds pressure, the solids build within the chambers until they are completely full of solids, forming a filter cake.
Step 4: Once the chambers are full, the fill cycle is complete and the filter press is ready to be emptied. This is accomplished by separating the filter plates from each other.
Once the chambers are full, the fill cycle is complete and the filter press is ready to be emptied. This is accomplished by separating the filter plates from each other.

Discovering the Right Filter Press

Many different factors contribute to the overall success of a filter press. An ideal way to determine which filter press model is optimal for a specific application is to send a slurry sample to M.W. Watermark’s in-house laboratory. In the laboratory, technicians will analyze the sample to determine the most effective feed pressure, filter cloths, type of filter press, and whether any additional chemicals would assist the process.

M.W. Watermark partners with clients to navigate them through each stage of this process. Custom water and wastewater treatment filter presses are versatile and can meet the needs of any customer. Contact an M.W. Watermark Sales and Service team member to discuss your specific application and learn if a filter press is the right solution for you.

About M.W. Watermark

M.W. Watermark wants to make a difference. We are passionate about the world’s water. We are innovative, focused on customer service and always try to exceed expectations. We are an environmentally conscious company with people who are energized, encouraged and inspired to make a difference in the water business, and as a result, make a positive difference to our planet by helping to keep our shared, finite water supply clean and usable for generations to come. We build amazing, custom water and wastewater treatment equipment. We also specialize in rebuilding used water treatment equipment. Together, we can make a difference.

Product names, logos, brands, and other trademarks featured or referred to within this document are property of their respective trademark holders. These trademark holders are not affiliated with M.W. Watermark in any way.

Filter Press 101

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