Liquid Conveyance and Collection Systems

Featured at InterPhex '98
Airvac Vacuum liquid conveyance and collection systems consist of three basic components:

• The Airvac vacuum interface valve package (collection basin, vacuum interface valve, and pneumatic controller/sensor unit).
• The Airvac piping network (liquid transport mains, branches, and service laterals).
• The Airvac vacuum station (vacuum collection tank, vacuum pumps, liquid pumps, electrical panel, and control devices).

The collection process begins when fluid enters the valve package collection basin (sump). As the liquid level in the basin rises, air pressure increases against the pneumatic sensor. At a preset level, the sensor actuates the controller. The controller then opens the interface valve.

The open interface valve allows fluid collected in the basin to be evacuated into the piping network. Since the collection tank and piping network are maintained at 1/2 atmosphere (or less) of pressure, atmospheric pressure in the basin literally pushes the collected fluid into the piping network.

The lower pressure in the piping network and collection tank is maintained by vacuum pumps at the vacuum station. These vacuum pumps remove the air admitted with the fluid.

The vacuum mains empty into the collection tank at the station. Level sensors in the collection tank activate the liquid discharge pumps. The liquid pumps then transport the collected fluid to treatment facilities and/or holding tanks.

Overhead Vacuum System (OVS) technology provides lift capability of 23' allowing the piping network to be installed above floors, along walls, or across ceilings, while spaces remain in service.

Since the piping network does not have to withstand the pressure of burial or traffic loads, the primary factor that needs be considered when selecting material for the piping network is chemical compatibility with the fluid being transported.

Moderate pipe sizes (1.25" to 6") and minimal required pipe slope requirements (0.2%) simplify placement of the piping network in the building (above ceilings, on walls, around equipment, etc.).

Pipe accessibility facilitates future process modifications since disassembly and reconfiguration are not hindered by the necessity to cut floors, work in a wet excavation, remove contaminated soil, replace excavated soil with engineered fill, and patch the floor.

Individual Airvac vacuum interface valves can be serviced or repaired without interrupting service at any other input point.

Water costs and wastewater treatment costs are minimized when OVS technology is utilized to provide segregated collection routes for fluids requiring different levels of treatment.

Fluid is transported in the OVS piping network at velocities of 15-18 feet per second. This characteristic virtually eliminates the conditions which promote bacteria growth.

Airvac, Inc., 4217 N. Old U.S. 31, P.O. Box 528, Rochester, IN 46975. Tel: 219-223-3980. Fax: 219-223-5566.