We continuously receive calls from cooling tower homeowners describing the following: “I have a metallic crossflow tower that has been working for a few years now, and there are a variety of water droplets coming out of the top of the tower, a lot worse than before. What’s unsuitable and how do I repair it?/p>
First, we focus on that the term for the “water coming out the top of the toweris called “drift.Since the drift is a new incidence, it appears obvious one thing has modified within the tower. Barring any major water stream modifications, we begin asking questions like these: Does the tower have a separate layer of drift eliminators? In that case, have they fallen out of position, or have they got giant gaps between them? If the tower has drift eliminators integrally formed into the hanging fill sheets, how do they appear?
In most cases, the owner will tell us that it appears like there are a pair sheets that look somewhat “abnormalin comparison with the remaining. These sheets appear like they’re “oozingout of place. What is definitely happening is the PVC sheet has failed at the skinny location the place the sheet is hung upon its assist members.
Over time, both the vibration and fluttering of the air over the fill sheet has fatigued it to the point of fracture, or the weight of the water and scaling/fouling has over-pressured the sheet and brought about it to stretch and break. The sheet then transfers its weight to the sheets next to it, inflicting added stress on those sheets, that are additionally experiencing elevated air velocity as a result of opening left by the failing sheets. Next, the unfastened hanging sheets begin to flutter violently and beat themselves apart, causing the failure to spread rapidly. Fill sheets will continue to fail in both directions from the initial failure until the fill falls out of the tower or leaves a large opening in the fill part. This cascading failure of hanging sheets permits air and water to bypass the media and produces an increase in drift droplets escaping the tower, which brings us again to the owner’s original concern and the prognosis of Hanging Sheet Syndrome, or HSS.
So how can the owner appropriate HSS? There are two choices:
1. Replace the failing fill sheets with more of the identical hanging fill sheets
2. Exchange the fill sheets with thicker, backside-supported rigid fill blocks.
If the proprietor decides so as to add extra hanging sheets, consideration should be given to making certain the proper variety of fill sheets get put in into the tower. When the cooling tower was initially constructed, it was simple for the factory to position the sheets into the tower after which place the endwall on the tower to lock in the right variety of sheets. In the field, nevertheless, trying to get the proper variety of sheets into the tower without inflicting critical injury to the brand new sheets may be very tough. Failing to do so implies that the sheets could be free throughout the tower, and when the tower restarts operation, elevated vibration may happen, immediately fatiguing the sheets and starting the HSS over again.
If the proprietor chooses to replace the fill with backside-supported structural fill blocks, the opportunity of sheet stretching or fluttering is eliminated because the product is rigidly adhered into strong blocks. Usually, since the fill is designed for structural issues, these fill sheets are additionally much thicker than hanging sheets, wherever from 20-85% providing added longevity and UV resistance. As soon as the fill is installed properly, it is a uniform and rigid block that eliminates the potential of HSS recurring within the tower.
hanging sheet (MX75 cooling tower fill)