Selecting Filter Press Cloth: Performance Factors

Vishal Patel
Use of Filter press cloth in a Filter press machine
Why is it essential to clean Filter cloth material

Filter cloth in a Filter press is used to segregate liquid and solids from the slurry once it is pushed between the empty spaces of filter plates. At first, some tiny slurry particles go through the filter cloth material. The process continues until a film of dehydrated solids collects on the surface of the cloth. The collected solids then begin to filter other slurry material encapsulating all the solids and allowing only clean liquid (i.e., the filtrate) to go through the filter cloth.

The continuous filtration of the slurry material will cause wear to the Filter cloth material after a certain period. Normal wear can also happen on the surface of the cloth when the cakes are released from the Filter press machine at the end of the dewatering cycle. Wearing of the cloth depends on various factors such as the cake material's abrasive features and how resistant the cloth material is. One cannot accurately predict how long-lasting a Filter press cloth should be, but a good quality cloth will last for thousands of cycles.

During the normal operation of a press filter machine, tiny slurry solids will collect and form a layer on the Filter cloth material. The buildup on the Filter press cloth is determined by factors such as the design of the Filter cloth, particle size distribution, operating hours, chemicals used in the upstream process, and slurry material make-up. The filter cloth material should be rinsed weekly with clean water for the press filter machine to work efficiently. The rinsing process eliminates all the extra buildup from the cloth. Continued buildup of slurry accelerated the process of cloth wearing and may lead to a blowout of slurry during normal operational procedures. Regular cleaning of the cloth surface helps extend the cloth life and sustain good filtration efficiency.

Filter Press cloth specification: Factors affecting their selection

One should keep various factors in mind while choosing the perfect Filter cloth selection.

Filtrate Alkalinity and Acidity:

One can choose a relevant and suitable Filter cloth material based on alkalinity and acidity. While Polyester Filter cloth material is highly resistant to acids, vinylon filter cloth is highly resistant to alkali. The one filter cloth which is resistant to both alkali and acid is the polypropylene Filter cloth material.

The temperature of the filter material

The working efficiency of the filter cloth material is majorly affected by temperature. The filter cloth most resistant to temperature is polyester.

Release of Filter cake

The working efficiency of the Filter press machine is directly influenced by the release efficiency of the filter cake. If the exterior of the filter cake is non-sticky and smooth, the filtrate will quickly pass through the filter cloth. Thus, it will have a high filtration efficiency. To establish such efficiency in filtration, choosing a satin filter cloth or a single silk filter cloth is vital.

The shape of the filter cake

You can decide the wear resistance of the filter cloth material on the fact whether the size of the particle is hard or uniform. The nylon and polyester filter cloth materials are the best in wear resistance.

Filter press cloth – Factors influencing its performance

There are various factors affecting the selection of Filter cloth material.

Cake release

Different filter press cloths exhibit different cake release characteristics. The selection of a proper filter cloth material will ensure proper cake formation. When the cake is dried properly, it eliminates the need for excess cloth scraping. In addition, appropriate cake dryness also reduces the expenses of hauling away the filter cake. Thus, it is important to select an appropriate filter press cloth because the appropriate dryness of the cake is important for the effective filtration process.

Ease of cleaning of Filter cloth material

How often does one need to clean the filter cloth in the Filter press machine? The answer to this question depends on the type of press filter machine used. Some filter processes require cleaning the filter cloth material after each cycle or during the process. So how can one clean the filter press cloth, and what material is used to clean them? One can use a spray bar to clean the filter cloth material, but it may also produce extra wear and abrasion on the cloth. If the filter cloth materials remain dirty, it will not efficiently carry out the filtration process.

Size of the particle

The particle size is an important factor influencing the decision of filter cloth selection. Different fabrics are used to control different particle sizes. If the pores of the cloth are too big, the particles will easily pass through it without the obstruction of the Filter. Similarly, if the pores of the cloth are too small, it will stop the slurry from going through it. Thus, the size of the pores plays a vital role in the performance of the filter cloth material as it should allow the liquid to flow through but still builds a filter cake.

Distribution and shape of the particle size

Just as the particle size plays an important role in filter cloth selection, so does the particle size distribution. In some filter processes, all the particles are of the same size. However, in other processes, large particles are assorted with fine particles.

Sometimes, when the particles are of different sizes, the material needs to be processed multiple times to be efficiently filtered. The first process will grab the largest particles on the filter cloth but not the smaller ones. The second process will catch medium-sized particles leading to a buildup of a thicker cake on top of the largest particles.

The particles' size influences the filter cake's buildup, how it sticks to the filter cloth, and how much wear it causes to the filter press cloth, thus influencing the performance of the filter cloth.

What Are The Mainly Types Of Filter Press ?

The filter press machine is the equipment used for the separation method to separate solid and liquid. Filter press machine working consumes low energy, low to no human resources required, and high separation effectiveness of liquid filtering out, making it extensively used dewatering technology. Filter press is a widely used dewatering technology in papermaking, pharmaceuticals, food and beverage industries, mining operations, chemical industries, mills, marble, and stone cutting.

Advantages and Process of Automatic Filter Presses

The first and foremost type of filter press that is the Automatic filter press, differs widely from an old filter press machine. The basic structure, working principles, and process technology are similar to conventional press machines. In 1853 the British patent used the first form of filter press for procuring seed oil through various pressure cells.

How Filter Presses Are Used In Various Industries?

In the mid 19th century in the United Kingdom, one used a rudimentary form of filter presses to extract vegetable oil from seeds. However, when in the 20th-century, major developments took place everywhere; scientists developed an automatic horizontal-type filter press. Since then, filter presses have gone through a lot of technological advancements and changes.