Unlike most other flume styles which were developed for irrigation flows and then applied to other uses, the Palmer-Bowlus flume was specifically designed to measure sanitary sewage / wastewater flows from the outset.
The Palmer-Bowlus flume is widely used to measure industrial discharges, municipal sewer flows, and influent / effluent at wastewater treatment plants, and is second only to the Parshall flume in popularity.
Palmer-Bowlus Flume Accessories
Openchannelflow offers a range of accessories to assist you in customizing your Palmer-Bowlus flume. In general, the accessories offered are one of four types:
Piping / end connections
Flow condition options
Flow meter mounts
Sampler / parameter mounts
Custom configurations (nesting, surge boxes, etc.)
Palmer-Bowlus Flume Applications
Typical Palmer-Bowlus flume installations:
- Industrial pre-treatment
- Dam seepage monitoring
- Cross jurisdiction flows
- Sewage treatment plant flows
- Spring discharge
- Well pumping tests
Designed for installation in existing manhole channels and inline with sewer piping, Palmer-Bowlus flumes have a U-shaped cross section to minimize the transition of flow through the flume. The throat of a Palmer-Bowlus flume is created by a raised trapezoidal ramp section. As the floor of the flume rises, the sidewalls also contract.
The result is that flow is accelerated through the throat by the combination of change in floor elevation and vertical constriction of the sidewalls. Unlike the more common Parshall flume, there is no need to accommodate a change in elevation. Both the inlet and outlet of the Palmer-Bowlus flume are at the same elevation.
Like Cutthroat and RBC flumes, the design of the Palmer-Bowlus is dimensionless, with each flume size based upon a standard design. The dimensions for any particular size Palmer-Bowlus rely on only one dimension, D - the width of the flume. With D known, all of the other dimensions can be readily determined.
five variations of Palmer-Bowlus flume:
- Permanent Style with Integral Approach
- Short Section Style with Integral Approach
- Permanent Style without Approach
- Insert Style
- Cutback (Insert) Style
Each variation serves a particular purpose. For a more in depth discussion of the various Palmer-Bowlus styles, their layouts and applications, refer to the Dimensions section of this site.
The point of measurement in a Palmer-Bowlus flume is located a distance D/2 upstream of the beginning of the throat ramp (where D is equal to the flume size).
Palmer-Bowlus flumes are of the Long-Throated type. As a result, they can be calculated by computer analysis (versus Short-Throated flumes like the Parshall which are empirical devices and must be laboratory calibrated).
Over the years 18 sizes of Palmer-Bowlus flume have been marketed, with throat sizes from 4 to 72-inches. In practice, it is rare to see Palmer-Bowlus flumes in sizes above 24-inches.
The Palmer-Bowlus flume is the result of the investigations started in the 1930's by two engineers of the Los Angeles County Sanitation Department, Harold Palmer and Fred Bowlus, into adapting Venturi flumes for use in sanitary sewers.
The goal of their investigations was to develop a simple, low cost flume that adapted easily to the round pipes and U-channels found in sanitary sewer applications.