Winter is fully upon us, and continuing to accurately measure flow becomes a persistent and irritating problem. Flumes that are designed for measuring runoff are the most affected by the cold weather, and H-Flumes in particular, which are mounted above or at grade. Because these flumes don’t generally see a continuous flow, they can be more susceptible to submergence, frost heave and blockage. Learn how to use an H-Flume in cold weather and keep your flow clear.
The H-Flume in Cold Weather
Because H-Flumes are prone to freezing over, most approaches to using them effectively in cold weather are dedicated to keeping the water moving instead of freezing. These include tactics for insulating, attracting solar radiation, and adding embedded heat within. Let’s look at each in a bit more detail.
Insulating Your Flume
If your flow stream is measurably warmer than the exterior atmospheric conditions, or if you can add supplemental heat such as radiant heat, an insulated flume cover can be an ideal solution. This helps to keep snow and ice out of the flow and keeps the heat inside, which results in water continuing to flow freely. Most commonly, insulated covers are placed over an H-Flume’s approach section, but they can be fabricated for the flume itself as well.
Attracting Solar Radiation
If you don’t have exterior power or the ability to inject supplemental heat, you’ll want a way to attract and trap environmental heat, like solar radiation. In this case, it can often be helpful to coat the entire flume with a black coating. Often this is gel paint, but other approaches can be considered. This will help to draw sunlight and trap the heat inside. Because this approach depends on the sun, it’s important to make sure your flume isn’t in a shaded area, and where it can be kept free of snow and ice buildup.
Adding Embedded Heat
Embedded heat is by far the most effective way to keep your flow from freezing over. This method involves adding heat to the flume as opposed to the water flow. When you take this approach, you add heating elements within the flume, usually in the laminate. Such elements can be controlled thermostatically and independently or can be self-regulating. They can be added to the floor, sidewalls or stilling well, and even at all three points.
The standard heat differential between heated and non-heated flumes is 20 degrees. You can increase this differential by adding even more heating elements if you wish. The biggest advantage here is that your added heat can be easily concentrated at the points most likely to freeze over, which in H-Flumes are the discharge, nose and stilling well.
The disadvantage of embedded heat is that it requires an external power source to make the heating elements work, and it incorporates a dark coat on the exterior of the flume. In effect, it combines insulation and dark coating with powered heat. Still, it’s the best, most effective option.
Contact Tracom for Your H-Flumes
If you’d like more information about H-Flumes in cold weather, Tracom can help. Check out our selection of H-type flumes and get in touch with us today for more information or to place an order.