Is it necessary to install a water seal tank for natural gas vent flares?
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Is it necessary to install a water seal tank in the vent flare of a natural gas processing plant? When a natural gas processing plant is venting, the temperature of the vented gas can often drop to well below -50 degrees. Under such conditions, isn’t there a risk that the water seal tank’s water will freeze, thereby blocking the flow of vented gas and leading to safety accidents? I kindly ask the experts to share their insights.
This post was last edited by sundeili on 2011-9-26 at 15:19. A water seal is necessary; its function is to prevent backfire. Additionally, each water seal comes with a heating tube, whose purpose is to prevent the water from freezing
The last edit to this post was made by sjyygh on 2010-9-19 at 22:11. Natural gas processing plants typically use two systems in their vent flares to prevent backflow, one of which is a molecular seal. Another option could be a flame arrester, or it could be a water seal tank; each has its advantages and disadvantages, with the water seal tank generally being considered safer. Heat tracing is required; moreover, it is crucial that during production, low-temperature gas venting does not occur frequently – it only happens for short periods. When large amounts of gas need to be vented, the process should be designed to allow venting at normal temperature. The cooling capacity is not enough to freeze the water, so it’s released (there’s no time for extensive heat exchange), and with heat tracing in place, there’s no problem. Just consider whether the material can withstand low temperatures.
I came across several large natural gas processing plant projects that did not have water seal tanks. There is fuel gas used for purging at the end of the flare manifold, a liquid separation tank, and a molecular seal.
It is highly necessary to install a water seal tank on the vent flares of large-scale treatment plants to prevent backflow. For gas gathering and transmission stations, considering only molecular sealing is usually sufficient