You’ll find many distinctions between different types of flumes, but the size of the throat is one of the most important factors. Long-throated flumes and short-throated flumes both have benefits and drawbacks, and you should be familiar with both before settling for either. Take a look at the benefits of long-throated flumes to see if they will work for you.
Construction is an essential factor when planning any kind of flume installation, and the process works a bit differently depending on what kind of throat your flume has. A long-throated flume can be relatively simple with easy preparation. All you really need is a level channel, an approach ramp and a discharge ramp, though the latter may not even be necessary. In fact, long-throated flumes set up in a canal won’t even need an approach section either, as the canal itself serves as such.
Whether you’re installing in a canal or not, it’s always best to work with a flume fabricator to get the actual hardware. Trying to handle it all yourself can be tricky, especially if you’re not familiar with the technology and terminology involved. Working with a fabricator can get you a reliable device along with the ability to customize the design to your exact needs.
Calibration is one of the most important aspects of flow rate measurement, and long-throated flumes are generally among the easiest designs to calibrate. You can get within a +/- 2% head measurement error with proper calibration, which surpasses anything a short-throated flume can offer, as they peak at +/- 3-5% accuracy.
The device itself is just one aspect of accuracy measurements, so you’ll need to make sure it’s level, fabricated correctly and is appropriate for the flow. You’ll also need to consider the range of the device and how well the installation goes. Installation problems can cause inaccuracies before you even really get started. Don’t forget to optimize approach conditions as well because an uneven or supercritical approach could render all your measurements effectively useless.
Designing for Sediment
Long-throated flumes can easily handle sediment provided they’re designed correctly for it. No official guidelines exist for this particular issue, but that doesn’t mean you can’t come up with a workable solution. The primary factor is determining which style of flume you’ll want to use. Palmer-Bowlus flumes, for example, can sometimes have problems with upstream sediment deposits, but Trapezoidal flumes were specifically designed for passing sediment easily with no additional help whatsoever.
Long-Throated Flumes From Tracom
If you’re looking to enjoy all the benefits of long-throated flumes, Tracom is happy to help. Our flumes come in many different designs, but you’re always free to work with our team to find the right solution for your unique needs. Of course, if you think a short-throated flume would be a better fit for your open channel flow rate measurement conditions, we can help you with that as well. Contact our team today to get started and find the perfect device for your flow rate measurement needs.