Pneumatically driven drainage facility

Claim 1

A pneumatically driven drainage facility of the type wherein air and liquid travel through a common conduit in the form of alternating bodies of air and liquid, wherein the pneumatically driven air bodies drive the liquid bodies along the conduit, especially for long distances and/or large differences in height, and wherein the total distance of the facility is subdivided into a plurality of connected sections which are connected together at intermediate stations, at least some of said intermediate stations comprising a tank, said tank having inlet means for receiving waste liquid from a conduit and collection means for collecting the received liquid, a first branch line communicating with the tank above the surface level of the collected liquid for the passage through said first branch line of gas received in the tank at said tank inlet means, a second branch line for delivery of the collected liquid out of the tank, and including pump means for pumping said collected liquid into and through said second branch line, said first and second branch lines communicating with a descending conduit section located downstream from said tank, with the first branch line communicating with the descending conduit section above the level of the liquid therein.

Claim 12

A method of causing fluid flow in a pneumatically driven drainage facility comprising the steps of: subjecting the lines of the facility to a change in pressure to cause fluid movement therethrough, said movement comprising the air and liquid travelling through the conduit in the form of alternating bodies of air and liquid, wherein the pneumatically driven air bodies drive the liquid bodies along the conduit, boosting the flow at at least one intermediate station by receiving air and liquid therein, collecting liquid, passing out the air through a first branch line which communicates with the intermediate station above the level of the collected liquid, pumping the liquid through a second branch line separated from the first branch line, and into a downstream descending conduit section, and delivering the air from the first branch line into the descending conduit section above the liquid therein.

Claim 13

A method of causing fluid flow in a pneumatically driven drainage facility comprising the steps of: subjecting the lines of the facility to a change in pressure to cause fluid movement therethrough, said movement comprising the air and liquid travelling through the conduit in the form of alternating bodies of air and liquid, wherein the pneumatically driven air bodies drive the liquid bodies along the conduit, boosting the flow at at least one intermediate station by receiving air and liquid therein, collecting liquid, passing out the air through a first branch line which communicates with the intermediate station above the level of the collected liquid, pumping the liquid through a second branch line separated from the first branch line, and into a downstream descending conduit section, and delivering the air from the first branch line into the descending conduit section above the liquid therein.