PLATE FILTER PRESSES
AMP® automatic filter presses are used for dewatering sludges from washing aggregates and minerals after its sedimentation in a thickener tank. In the process of filtration most of the residual water is recovered from the slurry concentrate in the discharge from the thickener.
The filter press creates a cake with a minimum humidity that can be handled and stored without problems, by removing any liquid effluent, thus giving the best environmental solution in the treatment of aggregates or minerals.
The experience of our engineers in solid-liquid separation technology and, in particular, in the filtration processes, is clearly demonstrated by the numerous examples of automatic filter presses supplied by AMP to the metal mining, industrial minerals, construction, environment, ceramics, glass, marble and granite industries.
The specification of the suitable filtration equipment is calculated according to the variables of the process, and generally involves material testing in our laboratory scale pilot plant, or field trials. Based on the data obtained in these trials we determine the filtering surface which is defined by the size and number of plates which are incorporated into the filter, which is designed to be oversized, with a safety margin in anticipation of the future installation of extra plates, which could be undertaken with minimal disruption and additional investment.
AMP offers a range of models of press filters based on the sizes of plates, using standard sizes from leading manufacturers. The dimensions of the filter, with supported or suspended plates, will depend on the size of plates employed, number of plates, as well as the volume and moisture content of the cake.
The press is constructed as two heavy duty end frames joined together by two side rails or high beams, depending on how the plates are mounted. The filter pack comprises polypropylene plates with lateral supports, or trolleys in the case of the suspended design. Fabrics of polypropylene monofilament, polyester or polyamide, are selected according to the nature of the pulp to be filtered.
An electro-hydraulic device, incorporating a double acting piston, acts on the movable end plate, initiating the simultaneous opening of all plates in the "Cam" model filter, or by the dragging of individual plates in the "Shifter" model.
An optional anti-drip tray may be provided for collecting water from the filtration and fabric washing processes, if the filter incorporates this automatically operated device.
Pipework Assembly for feeding the filter, and collection of filtered, aerated and blown material.
Pneumatic valves for pulp and air circuits.
Central hydraulics comprising high and low pressure pumps, valves and distributors for the actuation of all equipment provided.
Automatic system to control the various stages of operation of the filter, including sludge handling, discharge and disposal of cakes, compressed air blower and cloth washing (optional). Safety device for opening/closing by pull switch.
Control cabinet with programmable operation via PLC with dialogue display screen and all measurement and control devices for the operation of the filter in automatic mode. All operating parameters can be adjusted depending on the variables of the filtration process.
In fill cycle, the filter is closed and feed slurry is usually introduced by a centrifugal pump controlled by a pressure sensor that gradually increases the speed of the pump, to fill the filter to the pressure required in the shortest possible time. Alternatively, piston/diaphragm are used pumps for high pressures of up to 1600kPa.
At the end of the fill cycle, detected by sensors that control the flow of filtered fluids, the feed to the filter valve is stopped and air is blown from the core of the filter. A second air valve produces aeration of the plate fabrics to assist the separation of cakes.
Then the opening of the filter pack commences, initiating the download of cakes.
In the model filter "CAM", with the filter open, a cycle of shocks of variable duration is induced to the plates, depending on the nature of solids that are processed.
The filter incorporates membrane plates when it is required to achieve maximum dehydration of the cake and reduce filter cycle time, resulting in an increase of the efficiency, and capacity, of filtration.
Automatic washing occurs after the discharging of the cake from the plate fabric, using a frame mounted on mobile cart in the upper beam that incorporates high pressure spray pipes and wipes the plate for quick and effective cleaning of the fabric.
The design of our filter presses, which are characterized by their high performance in terms of robustness, reliability, efficiency, operational simplicity and minimal maintenance, offer the following advantages:
- Fully automatic equipment without the need for operators.
- Rapid opening system that ensures maximum cycles.
- Recovery of water processed with returns above 95%.
- Dehydration of sludge or clays with a minimum residual moisture content, depending on the nature of the feed material.
- Minimum plant area required for installation.