5.4
Mode of operation
The Vacumat Eco works as an active degassing device with automatic top-up
5.4.1 Basic principle of degassing in the Vacumat Eco
Degassing is performed by removing system medium from the system circulation through a bypass. This is conveyed through the system
connection (A) and the following volume flow limiter (7) into the degassing vessel (8). During pump operation, the degassing vessel (8) is placed
under a defined negative pressure. The ability of air to dissolve in the system medium is heavily reduced by the lowered pressure, causing
bubbles to form, accumulate and expand and this air to rise.
The process is facilitated by the rotating air separator principle where the air is separated and unified by the tangential inflow, intensified
towards the middle of the vessel (in the air head of the degassing vessel). This optimises degassing.
All free gases and a proportion of dissolved gases are removed from the system in an energy-saving manner which is considered non-critical in
terms of:
• Corrosion.
• Heat transfer to heating surfaces.
• Flow behaviour in the system.
This works, among other reasons, because the frequency-controlled pump with adjusted speed gently regulates the vacuum to be built up to
an energetically meaningful level (temperature-controlled), thus avoiding pressure surges.
After reducing the pump speed, the vessel is placed under system pressure by subsequent medium flow, resulting in the
discharge of the air collected above water level via the de-aerator unit (16, 19-22).
The Vacumat Eco performs check degassing cyclically in order to automatically pause the degassing when the preset gas content level is
reached. This is checked and decided at the de-aerator unit.
Pressure switch (22) detects whether air still exists at charge level, which leads to preset vacuum control at the degassing system by (Reduced
degassing = MIN, Normal degassing [default] = MED, and Strong degassing = MAX).
The quantity of medium supplied to the vessel is returned to the circulation line system connection (B) return via a bypass line while the pump
is running. Cyclical degassing takes place in "Fully automatic" mode. In this mode, the pump running time (vacuum
build-up) alternates with the ejection of the separated air (reduced pump speed).
Although the Vacumat Eco works very quietly, fully automatic degassing operation mode can be interrupted by freely programmable breaks
(e.g., at night). It is also possible to switch off degassing. The system is then in standby mode. Topping-up can still be done in this mode as
needed.
5.4.2 Top-up
Both pressure-controlled and level-controlled topping-up can be performed.
Topping-up occurs when the motor ball valve (6) switches; medium then passes into the Eco Vacumat through the top-up opening (C) and is fed
to the system by the pump.
Topping-up interrupts breaks and standby operating mode, or follows completed cycles of normal degassing or check degassing.
If the top-up requirement is active, it is primary to all other processes because the pressure must be maintained above all else.
5.4.3 Pressure-controlled top-up
Equivalent to factory setting to top-up pressure holding systems with (passive) diaphragm pressure expansion vessels.
The top-up switch-on and switch-off pressures can be edited in the pressure screen.
5.4.4 Level-controlled or externally-controlled top-up (for active pressure maintenance)
The operator has the option to use the level-controlled top-up for pressure maintenance using an automatic pressure holding device.
(See terminal diagram / electrical connection) Topping-up occurs here for as long as the external top-up request is present and Vacumat Eco
volume or time-monitoring allows it.
5.4.5 Top-up OFF
Top-up can also be disabled via software in the Start menu.
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