Vacuum tanks are the original technology first used onboard marine vessels.
Vacuum tank systems consist of a vacuum tank (normally 1-6 m3 in capacity), vacuum pumps and sewage discharge pumps. Unlike the OnlineMax, for example, sewage is collected to the tank and discharged in batches. As with the OnlineMax, vacuum is created by special vacuum pumps but the vacuum tank also acts as a big vacuum buffer for the system.
Benefits of the vacuum tank system are:
- Good efficiency
- High capacity
- Vacuum buffer stabilizes the system
- System is easy to upscale
- Very good reputation
In a system with a vacuum tank collecting unit the whole tank is under vacuum.
Vacuum is generated by a special type of vacuum pump which can stand humid operation conditions. Vacuum generation is controlled by a vacuum sensor and the PLC. The vacuum tank is discharged by standard centrifugal pumps. Discharge is controlled by high level and low level switches or, optionally, by a timer.
See the technical information in the pdf file attachment below: