Filtering apparatus

An apparatus for the filtering of particles from a fluid comprising at least one substantially cylindrical filter chamber divided into two compartments by a support fabric for a precoat filter layer, the first of said compartments having at least one closable inlet opening for a carrier medium of the precoat filter layer, a closable inlet for the medium to be filtered and a closable inlet for a washing medium, the second of said compartments having a closable outlet opening for the purified filtrate, wherein said filter chamber is divided into two axially symmetric compartments by means of said support fabric, wherein said support fabric is planar and clamped along a ring-shaped rim region of said two compartments, and wherein each of said compartments is delimited parallel to said support fabric by a movable wall adapted to be pressed against said support fabric by means of external pressure, respective bottom plates flanking the assembly of said movable walls and said fabric and annular side walls surrounding said compartments and clamping said rim region of said fabric, a central channel formed in the filter chamber, said channel being formed by an internal side wall, wherein said support fabric and said two movable walls, each, have a central opening, said support fabric being clamped along a ring-shaped internal rim region between said internal side walls of said two compartments forming said central channel, and each of said movable walls being clamped along a ring-shaped internal rim region between said internal side walls and said bottom plates of said compartments.

A filtering apparatus comprising:

• an axially aligned cylindrical stack of filtering units, each of said units comprising:
• a pair of generally circular bottom plates, each of said bottom plates being formed with at least one passage for a first fluid medium,
• respective movable walls juxtaposed with said bottom plates and displaceable toward one another upon introduction of said first medium through said passages,
• respective annular members each formed with at least one passage and disposed in axial registry between said bottom plates to define annular side walls of respective circular compartments, said compartments being closed on opposite axial ends by said movable walls, and
• a circular support fabric clamped between said members and separating said compartments from one another;
• clamping means for drawing said stack together and clamping for each of said units respective bottom plates against the respective members and the respective members against a respective support fabric;
• and
• means connected to said passages for:
• (a) introducing a filter aid in a second medium into one of the compartments of each unit for deposition of said filter aid as a layer on the respective fabric,
• (b) withdrawing said second medium from the other compartment,
• (c) introducing a medium to be filtered into said one of said compartments of each unit,
• (d) withdrawing a filtrate from the other compartment of each unit,
• (e) introducing said first medium into each unit to press a filtered mass against said fabric, and
• (f) introducing a back washing medium into the other compartment of each unit while discharging a back washed suspension from said one compartment of each unit.