Filter press: an ancient history… for a new environmental deal!
In industry, Filter presses are commonly used to dehydrate sludge and recover processed water, facilitating savings and disposal.
The function of the sludge filter press is to create cakes inside chambers created between its plates and then dehydrate them thanks to a counter-pressure given by pneumatic pistons.
The pressure of the feed pump dehydrates the sludge and the water passes through a collector created by the holes in the corners of the filter plates, leaving the solid cakes in the chambers.
The cakes are then discharged onto a conveyor belt, inside a container or onto the ground before the cycle starts again.
Matec, in the last two years alone, has installed more than 250 water treatment plants scattered all over the world, but what are the origins of the filter press machine, which today has industrial uses in so many different sectors?
Going back thousands of years, we find rudimentary models of filter presses in various cultures from different parts of the World.
The first wooden presses used by the Latins and Romans originated between 100 BC and 400 AD and their scope was for the production of oil and wine.
The Egyptian XVIII dynasty of 1543-1292 BC, in the splendid kingdom of Tuthankhamon, produced wine by means of a sack press.
In China in 1600 BC, during the reign of Shang fu, the production of tea from camellia was done by means of another particular model of wooden filter press.
The turning point for the design of filter press machinery took place in the mid 1800’s in Great Britain, in the fulcrum of the industrial revolution.
A self-regulating machine with pressurized cells was launched in the production of oil from plant seeds, followed by the first model of steel filter press with plates that found its applications in the food and industrial fields.
In the twentieth century, for more than a hundred years, the filter press was introduced and used in the mining sector.
One of the most successful applications was in the recovery of zinc dust from cyanide solutions.
The filter press which dominated the scene during this period was Eimco.
With the introduction of plate and frame filter presses the problem that arose was the removing the filter cakes which remained attached to the frame and forced the operator to remove them manually.
A breakthrough in this direction came in 1959 thanks to K. Kurita and S. Suwa, who introduced filter presses with recessed chambers, which considerably improved the above-mentioned problem.
A further step forward in filtration technology came with the diffusion of membrane plates, which added a diaphragm or membrane to the recessed plate, physically squeezing each cake through water or compressed air.Over the years and according to the different needs, two production methods have been distinguished to support the plates : Overhead Beam and Side Beam.
Filter presses with the Overhead Beam style support the weight of the plates with suspended beams.
Instead, the Side Beam style filter presses support the weight of plates with beams running along the sides of the machine.
Today, with simplicity, flexibility and efficiency the filter press becomes an indispensable machine in multiple industries.
The Matec filter press dehydrates sludge by extracting water up to 90% recovery and forming sludge cake with residual moisture below 15%.