The CAT411 microfilter is a special cross-flow filter for
sampling from pressure pipes for the purpose of continuous
A self-cleaning effect results from the flow of medium at the
- Wastewater treatment plant
- Return activated sludge up to max. 4 g/l (4000 ppm) dry matter
- Excess sludge up to max. 4 g/l (4000 ppm) dry matter
- Secondary clarification
- Pressure on filter 0.2 to 1 bar (3 to 15 psi)
- Sampling in the bypass at higher pressures
Mode of operation
- High degree of operational safety thanks to robust design
- Simple cleaning reduces operating costs
- Easy and fast replacement of filter membranes
- Long service life
- Short response time of downstream measuring device due to low dead volume
- No separate energy requirements
- Easy installation
A sample flow of 0.8 to 1.8 m 3 /h (3.5 to 8 gal/min) is permanently conducted through the
microfilter via a pressure pipe. Some of the sample passes the filter membrane and is then conveyed
to the measuring device as filtrate.
The principle of cross-flow filtration is used for sampling. The PTFE filter membrane separates
particles > 0.45 μm from the filtrate. These particles collect in front of the filter membrane and are
washed away with the sample flow.
The medium is conducted in a meander-like channel through the filter element. A consistently high
flow velocity is achieved in this way. This causes the self-cleaning effect. Mechanical drives to
generate a flow at the filter surface are therefore not required.
A complete sample conditioning system comprises:
- Stamoclean CAT411 microfilter
- Collecting vessel
A sensor with a flow assembly can also optionally be integrated into the measuring system.