One of the most popular flume types in use across the world is the Palmer-Bowlus flume. While it has plenty to offer and can be the best option for a wide variety of different applications, you’ll find that some conditions make it offer more problems than solutions. Before you determine which flume style is right for your open channel conditions, it’s important to understand the potential flaws of this popular style. Here are the common problems with Palmer-Bowlus flumes.
Technically Not a Style
Palmer-Bowlus is typically referred to as a style of flume, but that’s not technically the case. It would be more appropriate to call the Palmer-Bowlus a class of flume rather than a singular definite style. Because of this, it’s easy for confusion to occur when it comes to taking measurements and applying them to complex equations. The dimensions and discharge characteristics will vary depending on the manufacturer of the flume. In the same regard, one Palmer-Bowlus flume cannot simply be exchanged for another if you go for a different manufacturer the second time.
Not Applicable to Low Flows
If you have a low flow in your open channel or flow that can fluctuate every now and then, a Palmer-Bowlus isn’t going to be all that helpful. This flume was originally designed to measure flows in piping systems and conduits under the assumption that the baseline flow wouldn’t change all that much. While an average flow constantly at all times would surely be convenient, that’s not the situation a lot of people have to deal with. If you need something suitable for low flows, a Parshall might work better. If you need something specialized for low flows, a Trapezoidal flume may be your best bet.
Sedimentation Can Occur
When the flow is easy and average, some minor solids can easily pass through a Palmer-Bowlus flume. If your flow rate fluctuates or the solids are particularly heavy, however, you may run into some problems. Solids can accumulate upstream of the throat ramp, significantly altering the dimensions of the flume and rendering all your measurements inaccurate. Some alternate configurations of Palmer-Bowlus flumes, like ones with rectangular cross-section throats, can sometimes be a solution, but your best bet is to simply use a different style better suited for the passage of solids.
Major Upstream Requirements
Every flume has upstream requirements that must be met in order to get accurate measurements. With a Palmer-Bowlus flume, those requirements are quite rigorous. At best, a Palmer-Bowlus flume requires 25 straight runs of pipe upstream without any bends, elbows or dips of any kind. This can be a tall order if you’re trying to implement a flume in a complex piping system in a treatment plant, for example. Without that extra space of upstream piping, the flow won’t be uniform enough for the Palmer-Bowlus to work properly.
Flumes From Tracom
With the common problems with Palmer-Bowlus flumes in mind, it’s time to find a flume that will work for you. At Tracom, we have a wide variety of options available, but you could always work with our design team directly to craft something that’s customized for your open channel flow application. Contact our team today!