ANDRITZ Pressure drum filter PYU
PYU filters guarantee highest filtration capacity per unit of area in any rotary pressure filter, with most effective cake washing
A more recent proven development of the YU filter is the pressure version, PYU. The rotating element remains un-changed, but is now supplied in a pressurized housing, suitable for operating pressures of 5 bar g and more. With this configuration and the added ability to discharge the filtered cake to atmospheric conditions, a single PYU filter can take the place of two centrifuges (one pressure and one atmospheric operating in series with a re-slurry step in between). Such applications have proved that the PYU pressure filter offers substantial savings in capital and operating costs, while at the same time providing distinct performance advantages (drier cakes, purer product and cleaner liquids).
Advantages of the pressure drum filter PYU
- Up to 93% of filter area is constantly under vacuum or pressure
- High drum speeds up to 40 rpm
- Unrestricted gas and filtrate removal result in maximum pressure differential across the cake
- Slurries can be pumped directly from a pressurized reactor to the filter under high pressure, eliminating the need for an atmospheric stage
- Higher differential pressures can be achieved and maintained than on vacuum filters, translating into even faster filtration rates. At the same time, differential pressure is no t limited by the vacuum pump.
- Compact design: This feature reduces installation costs, minimizes required floor space, and facilities low-cost pressurization of the filter.
- All-metal drum: Corrosion and wear resistance, as well as the ability to accommodate high operating temperatures and pressures are the main benefits of this feature.
- High RPM: Throughput is increased, while the cakes are kept thin. The cake is formed four to ten times faster than by conventional methods. Cake cracking is minimized, cake washing is made more efficient, drying time is reduced, and cake discharge is made easier – especially for sticky cakes.
- Pneumatic cake discharge: The blow-back shoe is fitted with close clearances to the machined inside surface of the cylinder, sealing off vacuum or pressure at the point of cake discharge. Cake discharge is achieved by a pulse of gas behind the cake. Thanks to facilitated mechanisms, the life of the filter media is extended and blinding and clogging is minimized.
- Common gas and liquid removal: Both the gases and the liquids are drawn from the filter as a single stream. This allows for simplified internal construction and higher operational capacity.
- Self-agitation feed system: The inverted pyramid-shaped feed compartment eliminates the need for auxiliary mechanical agitation devices. Solids are kept suspended by the upward flow of the feed to the filter. This “gentle” method of agitation keeps particle degradation for fragile solids to a minimum and is much more effective than rocker-arm type mechanical agitators.
- Counter current wash: The internal wash collection pans assure discrete separation between washes. Thus, dilution of filtrate and contamination of wash liquids with the filtrate is minimized.
- Exclusive single-cell body: Unlike conventional multi-compartment filters, the ANDRITZ filter design permits virtually unrestricted flow of gases and liquids. The stationary filtrate piping eliminates plugging and vapor handling requirements are minimized through low pressure losses.
- Rolling-element bearings: All ANDRITZ rotary filters employ long life rolling-element bearings. A variety of bearing configurations is utilized, depending on the size of filter selected.
- Recirculated gas: With optional closed-loop and 100% sealed construction, this system is used to filter toxic or hazardous materials requiring inert gas envelopes. The recirculated gases are fed directly to the pneumatic cake discharge valve.
- Food processing and pharmaceutical: Aspirin, antibiotics, encapsulated materials, stearates, starches, winterized vegetable oils
- Chemicals: Terephthalic acid, bisphenol A, polymers, sodium sulfate, boric acid, sodium bicarbonate, isophthalic acid