Things To Keep In Mind When Sizing A Filter Press Machine

Vishal Patel 20 April 2022

Since the filter press is used in so many industries and manufacturing units, there are some factors you should consider while choosing a filter press system.

A filter press machine is utilized in various industries and manufacturing units to separate solids and liquids. The pressure filtration process separates solids and liquids in the press filter machine. A press filter machine primarily uses mineral processing, aggregate processing, municipal waste, chemical processing, water treatment, food, beverage, oil, gas, pulp, paper, and power generation. Filter press is utilized in many good assembling processing systems to manage the separation of waste material effectively. Filter press sometimes needs to recoup liquid or other solutions from the filtering process or wastewater or produce or retrieve dewatered solid materials.

Since the filter press is used in so many industries and manufacturing units, many different machine options are available for you to choose from. This blog mentions some factors you should consider while choosing a filter press system.

• The design of the plate influences a filter press machine

  Traditionally, when filter presses were first utilized, they had a sequence of simple rectangular frames between flat solid plates. The surface of the plate had channels and grooves so that it could remove liquid. The term 'plate and frame filter press.’ originated due to the design of this press filter machine. Solid material assembled on filter cloth between the frame and flat plates. When no solid material is left to be pumped in the frame area, the filter press splits up, and the solid material falls out of the frames.

  However, the plate and frame style design posed many difficulties separating the dehydrated solid material from the frame. Although the plate and frame style design is still used in many manufacturing units, today, most press filter machines use recessed filter plates or membrane filter press designs.

Recessed filter press

Recessed filter plates have flat surfaces in the area of the face of the plate, which eliminates the need for a frame. The filter plate has filter cloths on them. When a sequence of the filter plate is held together, empty spaces are created between the plates. A pump is used to compel the solid and liquid slurry material to go between the plates, where the recessed empty spaces hold solid material, and the liquid passes through the filter cloth. This liquid is released through ports in the body of the plate.

Membrane filter press

Like recessed filter plates, membrane filter plates in the press filter machine facilitate the separation of malleable solids and liquids. In membrane filter plates, dehydration occurs first by forcing the solid and liquid material between the filter plates. The pump is paused when no more material can be forced into the plate's empty spaces. The flexible plate surface of the membrane filter plate is enlarged with liquid, or compressed air, forcing the malleable plate surface into the dehydrated material. As the plate surface of the membrane filter plate enlarges, the collected slid material is squished, resulting in more water removal.

• Methods of eliminating filtrate water

The liquid discharged on a filter machine goes through the filter cloth put on the filter plate surfaces during dehydration. The liquid exits the filter plate surface through tiny ports in two or more plate corners. Open filtrate discharge is another alternative for discharging liquid from the filter press machine. Every filter plate consists of an internal port on both bottom corners in open filtrate discharge. The internal port allows liquid to be eliminated straight from each filter plate onto a drip tray below the press filter machine.

• Use of feed pumps in a press filter machine

  All press filter machines are given a slurry feed pump to compel the solids and liquids to enter the void spaces between the filter plates. The pressure generated by the pumping action helps develop the necessary force required to separate solids and liquids. A Centrifugal pump is the most commonly used slurry feed pump. Positive displacement pumps are also sometimes used to feed the press filter machines.

• Use of dual feed and core blow during the filtration process

  Feeding a filter press from one or two ends in an appropriately designed feed piping is possible. When a press filter machine is designed to feed it from two sides, it is feasible to complete a 'core blow'. When the filtration stage is completed and the feed pump is closed, wet slurry still gets left in the core hole of every plate. A core blow series is finished to eliminate the remaining core slurry before the filter plates are unbolted. The core blow series stops the wet slurry from being eliminated with the dehydrated cakes.

  The core blow is achieved by utilizing a pair of automatic valves linked to the slurry feed piping. Water at high pressure and compressed air force the slurry out of the core hole. When the pressurized water and compressed air are fed into one end of the press filter machine, the slurry is forced out from the other end, usually back into the slurry tank.

• Taking care of the filter cloth and drip trays

  The filter cloth between the filter plates helps gather solid particles while the liquid goes through the filter media. All filter cloth eventually becomes contaminated with some solid particles on the surface of the cloth and in between the spaces of the cloth weave. The adulteration of the filter cloth will affect the rate of filtration and its capability to hold the plates together.

  Manual cleaning of the filter is the most typical way of prolonging the life and efficiency of the cloth. A fully automatic method of cleaning the filter cloth is also used for deeper cleaning of the contaminated cloth and removing the particles from between the cloth weaves. A fully automatic washing system uses high-pressure cleaning showers that clean the filter cloth at regular intervals by the automatic position of cleaning showers for each filter plate.