Membrane Squeeze Filter Presses and Filter Plates

Membrane Squeeze Filter Presses and Filter Plates: How They Work and When Best to Utilize

There are three basic types of filter plates used in conjunction with filter presses. They include recessed chamber, plate and frame and membrane squeeze plates.

Membrane squeeze, or diaphragm squeeze, filter plates offer a number of benefits, from time savings to improving the lifespan of the membrane. M.W. Watermark™ offers membrane squeeze filter press/plate solutions to a range of industries. Discover how membrane (diaphragm) squeeze plates work and what advantages they bring to the table.

M.W. Watermark Membrane Squeeze (Diaphragm Squeeze) Filter Press

How Membrane Squeeze Filter Presses Work

Membrane squeeze presses operate similarly to recessed chamber and plate and frame filter presses that utilize polypropylene filter plates. However, the chambers in the filter plates have membranes to squeeze out the excess water from the slurry. As a result, this type of filter press may be able to remove a significant amount of fluid. And therefore, they can also reduce cycle time as long as the filter cake is compressible.

M.W. Watermark Membrane Squeeze (Diaphragm Squeeze) Filter Press Plates

Membrane squeeze presses and plates are also considered when the slurry has higher than average solids and/or has variable volume, and when the time saved by the squeezing process can be justified by higher equipment costs. (Time is money).

In a typical filter press application, approximately 80% of the solids are pumped into the press in the first half of the cycle, with the remaining half considered the consolidation stage. With membrane squeeze, the cycle is shortened and the cake moisture content is reduced (see chart).

M.W. Watermark Membrane Squueze (Diaphram Squeeze Filter Press and Plates - Squeeze Cycle Time Graph

Membrane Squeeze Equipment Requirements

The result is increased throughput and better liquid recovery. Adding membrane squeeze to a filter press requires a specialized plate stack, a squeeze water manifold, and a filter plate pressurization system. Typically, membrane plates are alternated with standard chamber plates in a “mixed pack” as shown in the photo below.

M.W. Watermark Membrane Squeeze (Diaphragm Squeeze) Filter Press and Filter Plates Diagram

The Membrane Squeeze Filtration Process

The filtration process of a membrane squeeze filter press typically includes six steps. Here’s how membrane squeeze filtration works:

  1. First, the follower presses the membrane filter plates together via the hydraulic cylinder, effectively sealing their surfaces.
  2. Once the press has reached the specified pressure, the pressurization stops and the press maintains the pressure.
  3. Next, the feeding process begins. During this process, the slurry is pumped into each chamber via the thrust plate’s feeding port. Under the specified pressure, the slurry begins to form a filter cake on the filter cloth while any liquids are forced out of the chamber.
  4. After the feeding process has concluded, the filter cake may be washed if required by the application. (The option for cake wash must be included in the manifold configuration). In some instances, air blowing may be used to further dry out the filter cake.
  5. Then, the membrane squeezing begins. Using high-pressure water or air, the filter plate membranes squeeze the filter cake in order to reduce its liquid content.
  6. Now that the filter cake is mostly free of moisture, the squeeze manifold pressure drops and the membrane on each plate returns to its starting position. The press is opened and the filter cake is discharged.
M.W. Watermark Membrane Squeeze (Diaphragm Squeeze) Filter Press Installed On-Site
M.W. Watermark Membrane Squeeze Filter Press Installed On-Site
Benefits of Using a Membrane Squeeze Filter Presses and Filter Plates

Now that we’ve discussed how membrane squeeze filter presses work, let’s summarize the benefits of adding a membrane filter press to your operation.

Because diaphragm filter presses utilize membrane technology, they greatly influence the dryness of the filter cake. When put head-to-head against standard filtration processes, membrane filtering achieves the lowest residual moisture values in the solid. This is vital in filtering applications where the degree of dewatering is of the utmost importance, especially in applications where the separated solid or liquid is the actual product.

In addition to achieving a high degree of dewatering, membrane squeeze filter presses and plates also help reduce the filtration cycle time. With a faster cycle time comes faster turnaround times, which consequently can lead to an increase in productivity.

Benefits of Replaceable vs. Welded Diaphragms

Another advantage of using membrane plates can be found in the option for replaceable vs. welded diaphragms. If the membrane component happens to break, the diaphragm itself can be removed and replaced, versus requiring the replacement of the entire filter plate. This provides for a significant cost savings and a quicker fix over waiting several weeks for replacement welded membrane plates to arrive.

Also, if chemical compatibility is a concern, replaceable diaphragms are offered in various materials of construction, including EPDM, NBR, Viton, and more.

M.W. Watermark Membrane Squeeze Plate with Replaceable Diaphragm/Membrane for Easy Replacement in Case of Breakage and Chemical Compatibility
Membrane Squeeze Plate with Replaceable Diaphragm
Membrane Squeeze Presses and Plates from M.W. Watermark

From chemical plants to gold mining and everything in between, membrane filter presses and plates have been used successfully in a number of applications. Find out if utilizing a membrane/diaphragm squeeze filter press is right for your particular application by reaching out to M.W. Watermark. Contact us to learn more or request a quote today.

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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Your Guide to Recessed Chamber Filter Presses and Filter Plates

Designed for efficient solid/liquid separation, recessed chamber filter presses and filter plates are popular in a wide array of industries, from industrial and municipal wastewater to chemical processing. Learn how these types of filter presses and plates work and their advantages. Then, reach out to a member of our Sales and Service Team here at M.W. Watermark™ to see if a recessed chamber filter press is right for your application.

M.W. Watermark 630mm Recessed Chamber Filter Press with Gasketed Filter Plates and Optional Expansion Piece
M.W. Watermark 630mm Recessed Chamber Filter Press with Gasketed Filter Plates and Optional Expansion Piece

What Are Recessed Chamber Filter Presses and Filter Plates?

Like all filter presses, recessed chamber filter presses work by using a pressure filtration system. Recessed chamber presses have filter plates that hang on a steel frame. These plates – usually made from polypropylene – come in gasketed and non-gasketed designs.

Gasketed filter plates help eliminate leaks, while non-gasketed filter plates make filter cloth installation faster since the cloths do not need to be pounded in, but may result in a bit of leakage. Regardless of which type are utilized, the filter plates are clamped together in a filter press using a hydraulic cylinder and pump. Since each plate features a recessed area, when the plates are pushed together, they form a chamber in which solids collect on the filter cloths.

M.W. Watermark Non-Gasketed Recessed Chamber Filter Plates in a Filter Press. (Filter Cloths Not Installed).
M.W. Watermark Non-Gasketed Recessed Chamber Filter Plates in a Filter Press. (Filter Cloths Not Installed).
M.W. Watermark Gaskested Recessed Chamber Filter Plates. (Filter Cloths Not Installed).
M.W. Watermark Gaskested Recessed Chamber Filter Plates. (Filter Cloths Not Installed).

During the filtration process, slurry is usually fed through a large center feed hole. Liquids will pass through the filter cloth and onto the drainage surface. The liquids will eventually make their way through the discharge piping and into a process tank or drain. Meanwhile, the solids will accumulate on the filter cloths in the cavity that was formed when the plates were clamped together. Depending on the nature of the slurry, recessed chamber filter presses and plates can produce filter cakes consisting of 20 to 85 percent solids.

Click below to watch our introductory video, which illustrates the role of filter plates, filter cloths and pressure filtration in forming a dewatered filter press cake in a recessed chamber filter press.

Recessed Chamber Filter Press/Plate Applications

Recessed chamber filter presses and plates are used in various industries to effectively separate liquids and solids. Some common industrial applications for this type of filter press include:

  • Stone Fabrication
  • Metal Finishing
  • Mining & Energy
  • Power
  • Industrial Wastewater
  • Municipal Wastewater
  • Lime Softening
  • Chemical Processing
  • Ready Mixed Concrete

Advantages of Recessed Chamber Filter Presses/Plates

One of the top benefits recessed chamber filter presses have to offer involves how they are fed. With a large feed hole in the center of the plate stack, the slurry is able to fill the cavities swiftly and more evenly. This helps rule out the possibility of clogging and blowing out, helping prolong the life of your recessed chamber filter plates. This is especially important in applications with high feed solids.

A second advantage of recessed chamber filter presses comes courtesy of the plates they utilize. As previously mentioned, recessed filter plates are available in both gasketed and non-gasketed versions – and even in non-gasketed plates, there is an option for the addition of latex that runs along the edge of the filter cloth to help minimize wicking. No matter which type of recessed chamber filter plate works best for your particular application, liquids can generally be contained with proper operation.

M.W. Watermark Gasketed Filter Plates with Filter Cloths Installed. Particulates Accumulate on the Surface of the Cloths to Form a Filter Cake.
M.W. Watermark Gasketed Filter Plates with Filter Cloths Installed. Particulates Accumulate on the Surface of the Cloths to Form a Filter Cake.

Finally, recessed chamber filter plates make it relatively easy to empty the filter cakes. When the press is opened and the plates are shifted, the filter cakes will typically fall out from the chambers into a cake hopper or drum for simple removal. If the cakes remain in place, minor manipulation from a spatula will usually release them.

Filter Cake Releasing from a Filter Press with Recessed Chamber Filter Plates
Filter Cake Releasing from a Filter Press with Recessed Chamber Filter Plates

Learn More about Recessed Chamber Filter Presses/Plates

Interested in taking a deeper dive into how recessed chamber filter presses are designed and how they work? Learn more.

Contact M.W. Watermark

M.W. Watermark offers both stock and customized recessed chamber filter presses to accommodate your exact specifications. If you are in need of a recessed chamber filter press, replacement recessed chamber filter plates or other aftermarket parts and retrofits, contact us today.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Options for Filter Cloth Attachment to Filter Plates

Filter cloths are the foundation to the solid/liquid separation process. It is the filter cloths that allow a filter cake to build up, and the the filter cake itself that ultimately does most of the dewatering. Therefore, it is imperative that the filter cloths are fitting correctly to the filter plates for the best filtration performance from the filter press.

There are two main types of filter plates found in filter presses that require filter cloths to be attached: CGR (Caulked, Gasketed, Recessed Chamber) and NG (Non-Gasketed).

Below we discuss the methods most commonly used for attaching filter cloths to each type of filter plate.

Attaching Filter Cloths to CGR (Gasketed) Filter Plates

When the prevention of  leakage is paramount, gasketed filter plates and cloths are preferred over non-gasketed. However, this can be at the expense of speed of installation. Gasketed filter cloths are manufactured with a rope sewn into the outer edge. This enables the cloths to be pounded into the grooves of the filter plate, which provides for a nearly water-tight fit.

However, this process can take some time, and usually involves a deadblow hammer and polypropylene installation wedge. To help speed up the process, M.W. Watermark™ offers a palm-sized pneumatic air hammer.

Click the video link below for a CGR cloth installation demonstration.

Video: How to Install a Gasketed Filter Cloth

M.W. Watermark also offers a complete CGR Filter Press Service Tool Kit. This handy tool bag provides everything you need for installing and servicing gasketed filter plates and cloths, and also includes the lighweight air hammer.

M.W. Watermark CGR Filter Press Service Took Kit (40033019) - Updated September 2018
M.W. Watermark CGR Filter Press Service Took Kit (40033019)

Attaching Filter Cloths to NG (Non-Gasketed) Filter Plates

When the ability to change filter cloths quickly is critical, and a small amount of leakage is acceptable, then non-gasketed filter plates and cloths are generally preferred over gasketed.

The faster cloth installation time can be attributed to the fact that zip ties are used to pull the edges of the cloth together around the filter plate. Any excess zip tie length can simply be clipped. These plastic ties can also be quickly clipped off when it’s time to remove and change out the cloth.

Non-gasketed filter cloths are also held in place using cloth dogs, which are plastic pegs that insert into small openings in the top of the filter plate. Grommets that are sewn into the edge of the cloth are quickly secured to each cloth dog using a rubber washer, effectively adhering the top of the cloth to the plate.

M.W. Watermark Cloth Dogs for Attaching Non-Gasketed Filter Cloths to Filter Plates
M.W. Watermark Cloth Dogs for Attaching Non-Gasketed Filter Cloths to Filter Plates
M.W. Watermark Non-Gasketed Filter Press Cloths Attached with Zip Ties, Cloth Dogs and Cloth Dog Washers
M.W. Watermark Non-Gasketed Filter Press Cloths Attached with Zip Ties, Cloth Dogs and Cloth Dog Washers

Although it’s difficult to completely eliminate leaks when using non-gasketed filter cloths, there are some tried and true methods for improving the sealing.

For example, latex can be applied to the edging of the cloths, which can help reduce wicking. Hook and loop fasteners can also be added during the cloth manufacturing process, which can improve the fit when attached to a filter plate. This more exacting fit can also help reduce leakage by keeping the cloth aligned correctly.

The use of hook and loop material can also aid in the speed of cloth changes, and eliminates the chances of small pieces of plastic (zip tie clippings, stray cloth dogs/washers) being introduced into the process. This can be especially important in applications involving chemical production.

M.W. Watermark Non-Gasketed Filter Press Cloths Attached with Hook and Loop Fasteners and Latex Added to Help Minimize Wicking
M.W. Watermark Non-Gasketed Filter Press Cloths Attached with Hook and Loop Fasteners and Latex Added to the Edging

Click on the video below for a NG cloth installation walk-through.

Video: How to Install Non-Gasketed Filter Cloths

Aftermarket Accessories

In addition to the CGR Filter Press Service Tool Kit, M.W. Watermark offers a wide range of Aftermarket Accessories to help make filter press operation and maintenance easier.

Download our Aftermarket Accessories Sheet to see our full selection of ancillary products.

Custom Filter Press Cloths Manufactured In-House

M.W. Watermark manufactures custom filter cloths in-house to fit the exact dimensions of most filter press plates.

This is accomplished by utilizing laser cutting tables and our experienced cloth sewing staff.

M.W. Watermark Manufactures Custom Filter Press Cloths In-House, Using Laser Cutting Tables and Our Experienced Cloth Sewing Staff

Contact Us Today

Contact our Sales and Service Team today to learn more.

Also, be sure to ask about our Filter Cloth Installation Service.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Signs Your Filter Press May Need Service

Does My Filter Press Need Service?

The filter press is a complex piece of machinery, and even with the proper maintenance, it’s still likely that your press will eventually need service. Ensuring your filter press receives the service it needs is essential in maximizing its life and streamlining your operation’s filtration efficiency. Not certain if your press needs service? Read on to learn more.

Does my filter press need service? Filter press field service; filter press maintenance; filter press repair

My filter press is leaking oil.

Oil leaks usually require immediate attention, and you may need service if you’re dealing with one. Try to examine the press to pinpoint the source of the leak. Sometimes, that source will be a damaged cylinder. These can be rebuilt or replaced, and these tasks are likely best left to an expert. The source could also simply be a loose fitting, which you can likely tighten on your own.

The filter cake is wet and slimy, even with new filter cloths.

This is one issue that can take a serious toll on your business’s productivity. You may be able to examine your filtration process to determine adjustments that may assist with the issue, but a trained filter press repair technician can typically provide valuable insight, helping to prevent similar issues from occurring in the future.

Filter press components are failing early.

Component failure is never a good sign, but the fix could be as simple as an oil change. Fortunately, changing your filter press oil is something you can probably do on your own. Not seeing any improvements after you’ve changed your oil? It’s likely time to reach out to a filter press professional.

The press isn’t properly regulating hydraulic pressure.

Here, you may be dealing with several issues. Start by trying to reset your relief pressure. If that doesn’t fix the problem, your relief valve may need to be replaced, so it’s worth calling a technician.

If pressure issues are accompanied by an oil leak, you may be able to perform the fix yourself by seeking out the source of the leak and tightening the fitting, as we mentioned earlier.

Should you get preventative service, even when nothing’s wrong?

Contacting a filter press technician even when there’s no specific issue isn’t a bad idea. In fact, regular preventative maintenance can work wonders in making the most of your filter press throughout its lifespan.

Need onsite support for your filter press troubles? M.W. Watermark™ offers TWIC-certified filtration equipment experts who are fully equipped to visit your business, address filter press trouble and train employees on proper press usage.

Contact us today to learn more.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Filter Cloths 101: Common Weave Patterns

The most common filter cloth weave patterns are plain, twill, and satin.

In addition to selection of filter cloth materials, weave patterns can be a critical factor affecting filter cloth performance. Weave patterns are recommended based on the nature of the slurry being dewatered, and can affect a cloth’s strength, resistance to acid and alkaline environments, ease of cake release and resistance to blinding.

 

M.W. Watermark™ Manufactures Filter Press Cloths with Weave Patterns to Suit the Requirements of Your Particular Application
M.W. Watermark™ Manufactures Filter Press Cloths with Weave Patterns to Suit the Requirements of Your Particular Application

What is meant by Warp and Weft?

Warp is the threads that run lengthwise in a cloth. Weft is the threads that run across the width of a cloth at right angles to the warp. These are also known as filling threads. Warp should run vertically when installed.

Common Filter Cloth Weave Patterns

Plain Weave

Plain Weave (or Checkerboard Weave) is the most basic weave, with a weft thread alternately going over one warp thread and then under one warp thread. Average in strength, cake release, and stability. High particle retention and low resistance to blinding.

 

M.W. Watermark Filter Cloths - Plain Weave Pattern

M.W. Watermark Filter Cloths - Plain Weave Pattern

Twill Weave

Twill Weave adds a diagonal rib or “twill” line into the weave, adding strength at the expense of some stability. These diagonals are caused by moving the yarn intersection one weft thread higher on successive warp yarns. Cake release is average. Average resistance to blinding.

 

M.W. Watermark Filter Cloths - Twill Weave Pattern

M.W. Watermark Filter Cloths - Twill Weave Pattern

 

Satin Weave

Satin Weave (or Sateen Weave) has a smooth surface caused by carrying the warp yarn on the fabric surface over many weft yarns. Intersections between warp and weft are kept to a minimum. Very flexible, easily conforms to most curved surfaces. Satin weave is popular for its excellent cake release and resistance to blinding. Particle retention is average.

 

M.W. Watermark Filter Cloths - Satin Weave Pattern

M.W. Watermark Filter Cloths - Satin Weave Pattern

Additional Weave Patterns

Leno Weave

The leno weave involves two or more warp threads crossing over each other and interlacing with one or more filling threads. This is known as a “locking” weave, as it is mainly used to prevent the shifting of fibers in open weave fabrics. This type of weave is usually only found in backing cloths.

Basket Weave

Basket weave is a variation of the plain weave. Two or more warp yarns alternately cross with two or more filling yarns. Stronger than a plain weave, at the expense of stability. Typically used for backing cloth or basic applications requiring additional strength.

 

M.W. Watermark™ Manufactures Filter Press Cloths with Weave Patterns to Suit the Requirements of Your Particular Application

Contact Us Today

Contact our Sales and Service Team today to discuss your particular dewatering application.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Plate and Frame Filter Press vs. Recessed Chamber Filter Press

Plate and Frame

What is a Plate and Frame Filter Press?

Plate and frame filter presses have been used for many years, and predate the recessed chamber filter press, which is the type that most people think of today when they hear the term filter press. Although recessed chamber presses are now more of the norm, the plate and frame design has some advantages with certain applications and is still used today.

M.W. Watermark - What is a plate and frame filter press and how does it work?

Plate and Frame Filter Press Design Overview

The plate and frame design utilizes a flat, solid plate (known as a “flush plate”) covered by a filter press cloth, with a hollow frame between each plate. A metal skeleton holds and clamps the filter plates together to create a chamber, which is formed by the flush plate on each side of a frame. Filter cake is collected within the frame. Historically, plates were made of wood or cast iron. Today, the most common material is polypropylene.

M.W. Watermark Plate and Frame Filter Press
M.W. Watermark Plate and Frame Filter Press

How Does a Plate and Frame Filter Press Work?

The slurry is pumped into a corner hole and flows into each frame, allowing solid particles to accumulate on the filter cloths. The remaining filtered liquid (also known as filtrate) then moves to a drainage port in the flush plate and into a corner hole that is not being used for feeding the slurry. The filtrate then travels to discharge piping and is directed to the next step in the process.

After a period of time, the frames become filled with solids, the slurry feed pump turns off, and the filter press is ready to open. Each frame should now contain a filter cake, which is the end result of the solids forming on the filter cloths. The filter cakes are then scraped out of the frames using a spatula, ideally falling into a cake hopper placed below the press.

M.W. Watermark - What is a plate and frame filter press and how does it work? Plate and frame filter press operation; Plate and frame filtration process M.W. Watermark - What is a plate and frame filter press and how does it work? Plate and frame filter press working.; Plate and frame filter press operation; Plate and frame filtration process

Advantages of the Plate and Frame Design

The primary advantages of plate and frame presses are the ability to quickly change the filter cloths as well as the ability to use a wider range of materials for the filtration medium, including paper, which is often used for fine filtration applications.

For example, in a process where immediate particle retention is important, filter paper may be required as fine solids would either blind off the filter cloth or simply pass through it. Note that filter cloths are still in place to support the filter paper. The filter cloths are reused, but the filter paper is replaced after every filtration cycle.

Plate and frame presses are best suited for projects where filtration area is more important than volume. This is why plates and frames have their greatest prominence in polishing applications (as opposed to dewatering projects), where the feed solids concentration is often well below 1% by weight.

Polishing applications are sized for a particular filtration area based on the process flow rate and the known flux rate (volume per area per unit of time). To avoid dips in achievable filtration flow as the press fills with solids, polishing applications usually include a redundant filter press that is also sized to accept 100% of the desired process flow.

M.W. Watermark Plate and Frame Filter Press Design

Disadvantages of Plate and Frame Presses

One disadvantage of the plate and frame design is the potential for building uneven pressure between frames, which can lead to plate damage. This issue stems from the fact that the frame is being fed through a small opening in the corner, which can lead to blockage. This clogging can cause one frame to become full while the next frame in-line remains empty.

Another disadvantage is the potential for leakage. The filter plates used in plate and frame presses are non-gasketed, which allows them to wick liquid under pressure. This type of filter press is usually mounted on a raised platform or positioned over a pit where any leaked liquids can be collected more conveniently.

Recessed Chamber

What is a Recessed Chamber Filter Press?

A recessed chamber filter press utilizes filter plates that form a series of cavities between them when they are clamped together. Suspended particulates collect on the filter cloths and build up inside each cavity space to form a filter cake. Compare this to the hollow frames of the plate and frame design where solids are collected.

M.W. Watermark 800mm Filter Press

M.W. Watermark Gasketed Polypropylene Recessed Chamber Filter Plates in a Press with Cloths Installed. Solids Accumulate on the Surface of the Cloths to Form a Filter Cake.
M.W. Watermark Gasketed Polypropylene Recessed Chamber Filter Plates in a Press with Cloths Installed. Solids Accumulate on the Surface of the Cloths to Form a Filter Cake.

Recessed Chamber Filter Press Design Overview

The skeleton of a recessed chamber filter press is constructed in a similar fashion as a plate and frame press where the plates hang on a steel frame, and the frame acts as a clamping device for the filter plates. Both types of presses also utilize a hydraulic cylinder and pump for opening, closing, and clamping the press.

As with plate and frame filter plates, recessed chamber plates are most commonly made from polypropylene. However, recessed chamber plates can be either gasketed or non-gasketed. Gasketed plates offer greater protection from leakage, but can also require a more time-intensive cloth changing process. Non-gasketed cloths or plate and frame cloths can have latex applied to the edges to help minimize (but not eliminate) wicking.

M.W. Watermark - What is a Recessed Chamber Plate Filter Press

How Does a Recessed Chamber Filter Press Work?

Slurry is pumped into the filter press through the feed (most commonly in the center of the plate) and the solids are distributed evenly in each chamber throughout the press (1). Solids begin to build on the filter cloths. Most of the solid/liquid separation is accomplished by the particulates building on the cloths. At first, some fines pass through, but eventually the solids begin to form a layer on the cloths (2). This layer traps the fine particles and eventually forms a filter cake. The filter cake then serves as a depth filter as the dewatering process continues.

The filtrate (liquid) usually exits the filter pack (plates) through corner ports into a manifold. When the correct valves in the manifold are open, the filtrate exits the press through a single point, the filtrate outlet. The filtrate is then directed via discharge piping to the next step in the process.

As the filter press builds pressure, the solids build within the chambers until they are completely full of filter cake (3). Once the chambers are full, the fill cycle is complete, and the filter press is ready to be emptied (4). The press is then opened, and the plates are moved apart. As the plates are shifted, the filter cake falls from each chamber into a cake hopper or drum below the press. A spatula can be used to scrape the cake from the cloths if needed.

M.W. Watermark - How Does a Recessed Chamber Plate Filter Press Work - Infographic
(Click Image to Enlarge)

Advantages of the Recessed Chamber Design

One of the main advantages of the recessed chamber plate design is the ability to feed a large center hole versus a small opening in the corner of the plate. The large hole in the center of the plates allows the chambers to fill faster and more evenly, with less risk of clogging and causing plate damage due to unequal pressure. This is especially important in applications with high feed solids.

However, it’s also important to note that a larger feed inlet (combined with gaining one more filtrate outlet in a center feed configuration) is important in large-scale polishing applications with high flux rates (for example, a Merrill-Crowe process). If the filter plate inlets, outlets, and internal porting are not large enough, the calculated press flow rate will not be achievable.

Another advantage is the ability to achieve higher feed pressure with the recessed chamber design. The “frame” or sealing surface of the recessed chamber plate is all connected to the center web. This keeps the “frame” from bowing out under high pressures.

Gasketed Recessed Chamber Filter Plate without a Filter Cloth Installed. Note How the "Frame" or Sealing Surface is Connected to the Center Web.
Gasketed Recessed Chamber Filter Plate without a Filter Cloth Installed. Note How the “Frame” or Sealing Surface is Connected to the Center Web.

Also, filter cake release is generally easier with a recessed plate. When the press is opened, and the plates are shifted, the cake either falls out or is quickly scraped off the cloths using a spatula. Cake release may not be as fast with a plate and frame press, as the filter cake is held by a non-tapered frame and may require more manipulation for removal.

M.W. Watermark - How Does a Recessed Chamber Plate Filter Press Work
Filter Cake Releasing from a Recessed Chamber Filter Plate

Disadvantages of Recessed Chamber Presses

Although recessed chamber presses have several advantages over plate and frame, one disadvantage is the limitation on cake thickness, which is dictated by the depth of the chamber. Recessed chamber plates cannot be easily swapped out for a wider or narrower frame as in a plate and frame press. This makes the plate and frame design better suited for applications where testing variations in filter cake thickness is important.

Another disadvantage can be seen in changing filter cloths. The plate and frame design allows for a simple drape-over cloth, whereas recessed chamber either requires pounding filter cloths into the plates (gasketed) or securing cloths to the plates using cloth dogs and zip ties or hook-and-loop fasteners (non-gasketed).

Contact Us Today

Contact our Sales and Service Team to learn more or request a quote today.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Benefits of Wastewater Staff Training and Other Field Services

There’s no denying that wastewater treatment equipment can be fairly complex, which makes it essential for equipment operators to know the ins and outs of every piece of machinery they’re required to use. This may require training for best results. Keep reading, and we’ll explain why you should consider professional field training services for your wastewater staff.

M.W. Watermark Filter Press Field Services Technician; Filter Press Repair; Field Training; Wastewater Staff Training
M.W. Watermark Field Services Technician, Brandon S.

Why Choose Staff Training from M.W. Watermark™?

M.W. Watermark’s time-tested professionals are fully equipped to train your staff on the use of your business’s wastewater treatment equipment. But what is it that makes M.W. Watermark’s training services worth the investment?

For one, our factory-trained, fully-insured service professionals have garnered significant hands-on experience with the types of equipment you’re likely using. Plus, as a further indicator of our team’s expertise, M.W. Watermark’s wastewater experts are TWIC-certified, a credential required by the Maritime Transportation Security Act that allows workers to access certain secured areas of the USA’s maritime vessels and related facilities.

One of the most notable benefits of field training is that it offers an opportunity for our wastewater professionals to provide advice regarding the efficiency of operating your equipment. While your team may be well-versed in operating equipment to your business’s current standards, our professionals may be able to identify areas for improvement – and once those changes are made, we’ll train your staff on operating your wastewater treatment equipment accordingly.

M.W. Watermark Engineer and Field Services Technician, Dave H.; Filter Press Repair; Field Training; Wastewater Staff Training
M.W. Watermark Engineer and Field Services Technician, Dave H.

Other M.W. Watermark Field Services

Aside from staff training, M.W. Watermark™ offers a range of competitively priced field services designed to help your facility maximize its efficiency. These services include:

  • Start-up Assistance
  • Installation
  • Mechanical Repairs
  • PLC Programming
  • Process Reviews
  • And More

If you feel your business would benefit from the professional assistance of M.W. Watermark’s team of wastewater treatment equipment professionals, contact us today.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

Filter Cloths 101: Common Fabric Types

The Importance of Selecting the Appropriate Fabric Type for a Given Application

M.W. Watermark Filter Press Cloth Manufacturer; Filter cloth for filter press

Filter press cloths can be manufactured from many types of materials including polypropylene, polyester, cotton, nylon and felt. Fabrics are usually selected based on the nature of the slurry being dewatered in a given application. Because filter presses are used across a wide range of industries, the characteristics of the suspended solids in a slurry can range from oily to fibrous to highly abrasive. The pH and temperature can also greatly vary.

The most common filter cloth materials are described below.

Common Filter Cloth Materials

Polypropylene

Polypropylene is the most common material. It has strong resistance to acid and alkali alike. A satin finish added to the fiber can allow for easy cake release. “PP” is a top choice for a wide range of applications, and is by far the most popular material.

Latex borders can be applied to a non-gasketed cloth to provide a better seal under pressure.

M.W. Watermark Polypropylene Filter Cloth; PP cloth; Filter press cloth specification
Click Image to Enlarge
Nylon

This durable fiber is often chosen for its long life in the face of abrasives. Though higher in cost, nylon blends offer such durability that the higher cost can be justified by longer service life.

M.W. Watermark Nylon Filter Cloth; Filter press cloth specification
Click Image to Enlarge
Polyester

Often chosen when sustained operating temperatures are over 180 degrees, or when oxidizing agents are present.

M.W. Watermark Polyester Filter Cloth; Filter press cloth specification
Click Image to Enlarge

Air Permeability Testing Matches Filter Cloth Fabrics to Specific Applications

By using a Frazier® Air Permeability Tester, M.W. Watermark™ is able to determine the air permeability of a particular filter cloth fabric, utilizing the ASTM D 737-96 standard test method for textile fabrics.

M.W. Watermark Air Permeability Testing Station
M.W. Watermark Air Permeability Testing Station
How does it work?

A sample is placed on the machine and air is drawn through the fabric. The rate of air flow passing through a fabric sample is adjusted to find an air pressure differential between two fabric surfaces. The air permeability of the fabric can then be determined by this air flow rate. The test results are reported in CFM, or Cubic Feet per Minute.

Efficiency of filtration media is directly related to air permeability. By testing the air permeability of a filter cloth fabric, our lab technicians are able to determine the filtration characteristics and determine if a given fabric is ideal for a customer’s particular dewatering application.

Learn more about our Laboratory Services.

Additional Online Resources

Visit our Filter Cloths 101 webpage for more information, including FAQ’s and cloth installation videos.

Or, visit our Filter Cloths main product page to download our product guide.

M.W. Watermark Polypropylene Filter Cloths - Ready to Ship; Filter cloth for filter press
M.W. Watermark Polypropylene Filter Cloths – Ready to Ship

Contact Us Today

Contact a member of our Sales and Service Team to discuss your particular filter press application.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

How Concrete Wastewater Can Be Recycled

More and more industries today are looking for opportunities to practice sustainability, and the concrete industry is leading the way. Concrete manufacturers, specifically those who make ready-mix concrete, are actually moving towards becoming zero-discharge facilities. A large amount of water goes into concrete processing, but instead of letting it go to waste, it’s being recycled and reused for a variety of different applications. As M.W. Watermark™ continues to supply the concrete industry with custom wastewater treatment equipment, we see firsthand some of the top ways water is being reused.

M.W. Watermark manufactures filter presses for recycling and reusing concrete wastewater

Where Concrete Wastewater Comes From

Ready-mix concrete is made from a mixture of paste and aggregates, like sand and rock. The paste is formed by cement and water and it’s used to bind all the aggregates together to make the finished product strong, yet workable. Some types of cement require more paste, and therefore water, than others. For example, if you want to achieve a stiffer consistency, less water is added to the mixture.

In addition to making the concrete, large volumes of water are also used to wash out the trucks. Water is run through the drum mixers and also sometimes used for pressure-washing. Both applications – concrete processing and truck washout – produce wastewater.

The Challenge of Reusing Wastewater

After it’s been processed, the water contains all sorts of impurities. It usually contains high amounts of suspended solids, lime, metals and sulfates with high pH levels. There are normally trace amounts of oil and grease from the equipment, too. As a result, this water can no longer be used for concrete mixing or washing, which is why it simply gets discharged. But when it’s discharged into our waterways, it disrupts aquatic ecosystems and kills fish along with their habitats.

In response to growing concerns about water availability and quality, concrete producers started looking for ways to treat this wastewater. This became especially relevant due to the Clean Water Act, which mandates the treatment of concrete wastewater. Today, these companies use filter presses and other treatment equipment to filter out most or all of those impurities to make the water clean again. While some shops put the treated wastewater back into the environment, others choose to reuse it.

M.W. Watermark manufactures filter presses for recycling and reusing concrete wastewater

Concrete Wastewater Recycling

With help from a filter press, waste from ready-mix systems, washout pits, block grinding and concrete cutting and grinding can all be recycled. As it turns out, this wastewater can be reused for both washing and concrete mixing. As long as the right quality control procedures are in place, it’s possible to use treated wastewater without diminishing the quality of the ready-mix product.

Osborne Concrete Co. is one example of a company that reuses its concrete wastewater. They were generating 50 gallons of wash water per truck. After working with M.W. Watermark to design and install a wastewater treatment process, almost 100% of the water became available for re-use. The filter press helped them cut back on costs and make it easier for them to comply with the EPA. Plus, they’re able to do their part in keeping the planet’s water supply clean and healthy.

Learn More About Filter Presses and the Concrete Industry

If you work in the concrete industry and are seeking ways to reduce the amount of wastewater you’re discharging, look to M.W. Watermark. We can help you determine the best strategy to recycle and reuse not only water, but recovered aggregates, too. Learn more about our filter presses or contact us to speak with a member of our team.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.

The Importance of Water Recycling and Filtration in Glass and Stone Fabrication

Glass and stone fabrication processes both generate a large volume of wastewater. Glass and stone fabricators are finding that they need to recycle and filter their wastewater for many of the same reasons.

M.W. Watermark manufacturers filter presses for glass and stone fabrication wastewater recycling and filtration

Environmental Regulations

The Clean Water Act makes it illegal to discharge the wastewater that comes from glass and stone fabrication processes without a permit.

However, the EPA will not generally approve discharge permits in these applications because the technology to recycle this water is readily available.

Municipalities will not permit discharge to sewers because stone and glass particulates can clog pipes. Glass fines accumulate and harden like concrete!

M.W. Watermark manufacturers filter presses for glass and stone fabrication wastewater recycling and filtration

Equipment Problems Resulting from Recycling Unfiltered Wastewater

It is important to not only recycle wastewater to comply with environmental regulations, but to also use industrial filtration equipment to remove the solids.

Glass fines, also known as swarf, can wreak havoc on glass fabrication equipment when water is recycled but not filtered. This is also the case with stone particulates and most stone fabrication equipment.

Unfiltered recycling can lead to greater maintenance costs, increased downtime, decreased production, and shorter equipment life.

Glass and stone fines not only cause excessive wear on moving parts, but they also accumulate in pipes – sometimes clogging them completely. In order to avoid costly repairs and downtime, while complying with environmental regulations, it’s important to have a filter press the shop can rely on.

M.W. Watermark manufacturers filter presses for glass and stone fabrication wastewater recycling and filtration

Custom Wastewater Treatment Equipment

For over 15 years, M.W. Watermark™ has helped businesses from a wide range of industries and applications, including glass and stone fabrication, with their wastewater treatment needs. We offer custom industrial filter presses specifically tailored to glass and stone processing operations. If you have any existing tanks or pumps, we’ll be happy to incorporate them into the system design.

Contact us today. Also, be sure to visit our glass or stone fabrication wastewater recycling web pages to learn more.

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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 on 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. Together, we can make a difference.

© 2019 M.W. Watermark, L.L.C.
M.W. Watermark is a trademark owned by M.W. Watermark, L.L.C. All rights reserved.
Any third party trademarks referenced on this site are the trademarks of their respective owners, and M.W. Watermark makes no claim to such marks and is not affiliated with such companies.