Definition - What does Pneumatic Ejector mean?
Pneumatic ejector is a mechanism installed in underground wastewater systems to eject the wastewater using compressed air to a discharge line, after it fills to a certain level. Some low lying places are not easily connected to the main sewer line for disposal to the wastewater treatment plant. In order to ensure that wastewater is effectively disposed off from all regions, low lying areas are provided with lift stations at strategic points to pump the sewage into the main sewer line, which is at a higher elevation.
Trenchlesspedia explains Pneumatic Ejector
The pneumatic ejector is a very simple mechanism consisting of a holding tank for collecting sewage. When the sewage fills up to a predetermined level, a valve located inside the tank forces pressurized air into the tank. A float in the tank responds to the level indicator by ascending and opening the valve to admit pressurized air.
The pressurized air forces the sewage out into the discharge line located at a higher level and the valve remains open till the wastewater in the tank reaches a low level. This causes the float to descend to the vent position in order to vent the pressurized air back to the atmosphere.
This automatic sewage ejection system is very advantageous in locations that cannot be directly connected to the main sewer line.