Filter press

A filter press is a device that performs the purification process in a large volume and separates liquids and solids from each other. Filter presses are mainly filters under pressure, which are made of plates that are placed between a fixed plate and a moving plate connected to a hydraulic jack and are pressed together.

The work of the filter press is to extract water from the slurry that has excess water. With the help of filter press, you can produce cakes with humidity between 19 and 25%. Nowadays, due to the high cost of using drying sludge beds, the use of filter press in the wastewater treatment industry has become very common in the country. In this device, by applying hydraulic pressure to the slurry, dewatering from the slurry is done by passing the liquid through the openings of the plates and trapping the particles and grains behind the plates.

Components of the filter press machine

A filter press device consists of the following components:

Chassis of the filter press machine: The chassis of the filter press machine includes the input parts of the filter, the back of the filter, the movable plate and the arms.

Filter press plate: The plates used in the filter press can be made of plastic, cast iron, or aluminum.

Frame of the filter press: The frame used in the filter press can be made of plastic, cast iron, or aluminum.

Jack and hydraulic unit of the filter press machine: The hydraulic unit part of the filter press machine consists of electric motor, hydraulic pump, hydraulic valve and hoses.

Types of filter press devices

Filter press or filters under pressure are classified into three general categories: manual filter press, automatic filter press and hydraulic filter press.

Manual filter press: The cheapest and simplest filter press model is the manual filter press. Manual filter presses always need an operator to operate and are controlled by human power. For this reason, manual press filters have a low performance speed and are used for small scales.

Automatic filter press: In automatic filter presses, operations such as opening and closing the jack, loading and unloading the cake, moving the press plates and washing the plates are done automatically without the intervention of the user. Automatic press filters are designed in two types of membrane and chamber. The difference between these two models in the act of compressing the suspension is the way the plates are placed and the type of plates.

Hydraulic press filter: In the hydraulic press filter, the movements of the press filter plates are done hydraulically. In the hydraulic filter press, electric control parts are added to the device to control the device and operation.


Press filter pages

The filter device has two types of chamber and membrane plates. Chamber plates are usually made of aluminum and cast iron and have sludge storage compartments. The cake formed in the chamber plates is about 60-70% dehydrated.

Membrane plates are 3 layers, the middle layer is responsible for bearing the pressure from the fluid. The material of this layer is usually pp, and the cake that is formed in these sheets is dewatered up to 90%. In most industries, especially when extracting more liquid from mud (cake) behind the screen or having mud with less moisture is considered, membrane filter press is used.


How the filter press works

In short, the function of the filter press is defined in 5 steps:

Filtration: The slurry enters the filter press from above and the filtration process begins.

Compression: In the compression stage, to separate the remaining water from the slurry, air or water is introduced with high pressure to the back of the slurry so that the slurry chambers are under pressure.

Dehydration with air: in the step of dehydrating with air, due to the separation of the remaining water, air flow is blown into the cake.

Cake discharge: The plates containing the cake are spaced apart so that they can be easily removed from the filter press.

Filter washing: Filters are washed with water to prepare for reuse.

The steps of making a filter press machine

The design and manufacture of the filter press includes the following steps:

Design, supply and preparation of steel and cast parts

Cutting of steel parts, which includes the arms of the filter press machine and the machining of the arms

Flooring of plates and frames

Drilling holes and installing handles on plates and frames

Stone work of cast parts and quality control of parts in terms of the quality of cast parts

Assembling the arms and initial and final parts of the filter press machine

Construction of hydraulic unit set

Installing the hydraulic unit on the chassis

Assembly of plates on the chassis

Turning on the hydraulic system and testing different parts

Dismantling plates and hydraulic unit

Reassembly and final test

Advantages of filter press

Ease of increasing capacity

Easy maintenance

Low energy consumption

High efficiency of sludge dewatering

Reducing environmental pollutants

No need for manpower

Low space requirements

Long life

Saving Water


Application of filter press

Filtration of particles in industrial oils

Sludge dewatering of sanitary sewage treatment packages

Separation of dissolved particles from wastewater

Wastewater treatment of oil and gas industries

Wastewater treatment of textile and petrochemical industries

Wastewater treatment of pharmaceutical and hospital industries

Kashefan Nilfam Engineering Company is proud to announce its readiness to produce filter press machines with various capacities and according to the requirements of the client. For more information about filter press systems, you can contact our colleagues at Kashefan Nilfam Engineering Company.

Filter press