AUTOMATIC BACKFLUSH FILTER
Constantly increasing levels of performance and the growing degree
of automation in hydraulically operated systems require all components
to function perfectly. It is therefore vital, for example, to ensure
that control valves work accurately. This has been achieved, among
others, by reducing the fi t tolerances between housing and piston. To
prevent that impurities in the hydraulic fluid as a result of this
development cause functions to fail in a system an effective filter has
been developed: The fully automatic backflush filter. This filter is used
as pressure filter in the main flow and in a hydraulic system has the
function of filtering and removing the contaminants of a hydraulic
fluid. These contaminants mainly occur in the form of metallic
abrasions, lacquer, rubbed off seal parts, dust, and scales. When no
backflush filters are installed these dirt particles are taken to all
points of a hydraulic system and can thus impair the functional
reliability of the system. The backflush filter consists of the filter
housing, the filter elements, and the control components. The standard
connection is a flange with nominal width DN51SSO which can be adapted
to the individual requirements by means of different fittings.
Contaminated pressure fluid enters the filter housing at the inlet. It flows through the filter elements from the outside in. Dirt particles which are larger than the pore size of the filter element are trapped. The filtered fluid leaves the housing at the outlet. The contaminated filtrate is generally removed via separate lines. The pilot valves are supplied with the backflushed hydraulic fluid internally.
Pressure sensors at the filter inlet and outlet measure the differential
pressure. The latter is an indicator of the degree of contamination:
Increased contamination of the filter causes the differential pressure
to rise. If the pressure difference exceeds a defined value the filter
element is automatically cleaned removing dirt particles from the filter
element. Based on preset parameters, the backflush process can be
triggered by differential pressure, time or a combination of the two.
The lower the differential pressure value set at the filter the more
of-ten will backflushing be performed. This essentially increases the
life of the filter elements. A signal transmitted from the control unit
activates the pilot valve which in turn triggers the back flush process:
The internal valves are reversed and the pressure fluid flows through
the filter element in the opposite direction for approx. 2 to 3 seconds.
The dirt particles are removed from the filter and drained via the
leakage port. While one filter element is cleaned by backflushing the
other element continues filtration to permit trouble free operation.
- Pressure-resistant backflush filter, nominal pressure up to 350 bar
- Fully automatic filter dewatering
- differential pressure or time control, or a combination of the two
- Electrohydrauic control
- Simple operation thanks to standard control units
- Made of surgical steel
- Suitable for all fluids
- Extended maintenance intervals