SPECIFICATIONS OF SLUDGE FILTER PRESS

The plates filter press supplied by Tecnoidea Impianti is the result of the company’s experience with filter press systems spanning over ten years. Thus matchless reliability and functionality are guaranteed, on the basis of state-of-the-art technology.

The filter presses are available in several models, ranging from mod. 630/4/45 with 4 plates 630x630x45 mm in size to mod. 1300/90/30 with 90 plates 1300x1300x30 mm in size.

Yields per operating cycle range from 0.07 m3 to 5 m3 dehydrated sludge. This means average hourly yields of 0.2 m3 to 15 m3 dehydrated sludge or average daily yields of 1 m3 to 400 m3 dehydrated sludge.
This data refers to two to six pressing cycles per hour. Since actual yields depend on the type of sludge being processed, 1 to 10 pressing cycles per hour may be required.

The size of the plates filter press should be determined on a case-by-case basis for 20 to 24 hours’ operation. This is a prerequisite condition if returns on investment are to be maximized.

The filter press is equipped with a heavy, sturdy, stress-resistant metal frame synonymous with remarkable reliability and a long service life. All the component parts of the filter press are carefully built and assembled. In addition, the unit is specially designed to provide easy access to all the parts. Since the filter press operates automatically, continuous supervision by the operating personnel is not required; only periodical inspections during work shifts are needed.

All of the filter presses supplied by Tecnoidea Impianti are given unique anticorrosion treatment which involves SA 2.5 sandblasting down to bare metal and subsequent flame metal spraying of a layer of 99.99% pure zinc 70-90 µ in thickness. Finally, two coats of two-component epoxy paint are applied to provide the metal frame with total protection, which is a top priority, since the filter presses will operate in highly corrosive environments.

The sturdy filter plates supplied by Tecnoidea Impianti are equipped with durable polypropylene filter cloths – their service lives usually ranging from six to twenty-four months – which can easily be replaced.
During the pressing cycle, the filter plates are hydraulically closed at a pressure of 280 bar. Liquid sludge is then pumped into the filter chambers and kept under constant pressure to simultaneously produce the following results:

· Firstly, water in liquid sludge goes through the countless lattices in the filter fabric and is expelled. Water is discharged through the drainage offlets at the bottom of the plate.

· Secondly, the solid substances held in suspension are filtered out of liquid sludge. Since the solid particles are larger than the lattices in the filter fabric, they are retained by the fabric and accumulate in the form of dehydrated sludge panels.

The concentration of dry solids in the dehydrated sludge panels varies according to the length of the filtration cycle, which can be adjusted by simply changing the position of a level sensor in the filtered water discharge offlet on the filter press.

Dry solid concentrations of 65% to 85% can normally be reached in filtration plants for the aggregate washing industry. The lower the position of the sensor, the more dehydrated sludge; the higher the position of the sensor, the less dehydrated sludge. The length of the filtration cycle is proportional to the degree of sludge dehydration required.

When the filtered water flow falls below the level sensor, the sludge pump automatically shuts down. At the same time, hydraulic pressure on the filter plate pack is reduced to zero, thus causing the hydraulic piston to recede. When this occurs, the piston pulls all the filter plates into the open position and the dehydrated sludge panels detach from the plates.