Is it reasonable to add an overflow pipe to the vacuum dechlorination tower?
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This post was last edited by sunjl1981 on 2013-1-6 at 23:44 :) I would like to ask the professionals here: For a vacuum dechlorination tower, in order to prevent situations such as sudden shutdowns of transfer pumps or failures of level control valves, which could lead to an excessive liquid level in the tower and disrupt normal operations, is it possible to install an overflow pipe on the dechlorination tower? If so, what type of pipe should be used so as not to affect the vacuum dechlorination process? A U-shaped water seal, or a programmable valve installed on the pipe, or something else? I appreciate any advice you can give. Thank you: handshake This post was last edited by limingshuguang on 2008-1-3 at 21:19 ] # ， ， &
The liquid level in the vacuum dechlorination tower is generally kept at 30%-40%, which provides sufficient headroom and time for handling any issues, making it unnecessary to install an overflow device. Adding an overflow device is not only unnecessary but also prone to causing instability in the system. :L
Agree with the opinion from the 3rd floor; adding an overflow pipe could lead to instability in the system vacuum
Moreover, a large amount of free chlorine enters the wastewater or brine system. . . .
If safety is ensured, it can be considered! I think the original poster’s idea is good!
:) Thank you all for your analysis. Since I’m not an expert in this field... We usually keep the liquid level in the tower at around 65%, and the diameter of the tower is also relatively small. Once problems arise, the liquid level fluctuates significantly, which is why... well, I asked for your help, haha. Sorry if this was awkward
:), thank you for your participation.:handshake As for that excess saline water, we have special tanks designed for its recovery and re-dechlorination; that’s why I’m asking how feasible it would be to add an overflow pipe. Sorry for the question.:loveliness:
:Loveliness: I hope all readers will leave their valuable comments!:handshake I’m sorry for taking up your time; please forgive me!
Regarding the situation described by the poster: 1. Shutdown of the dechlorination brine pump: Generally, the liquid level in the dechlorination tower is interlocked with the discharge valve of the brine tank (Asahi Kasei LCV-260). Therefore, if the shutdown of the dechlorination brine pump goes unnoticed and not addressed in a timely manner, it may cause the liquid level in the brine tank to reach the set interlock value, leading to a system shutdown. You can calculate the shortest time required to restart the pump or restore normal operation based on the size of the dechlorination tower and the HH level. It is also important to conduct regular emergency training for the personnel responsible for on-site inspections. 2. Fault in the control valve for transporting dechlorinated brackish water: Bypass regulation can be used, or the valve can be repaired or replaced. As for the overflow pipe, in theory it can be increased (whether it’s useful or not), but several issues need to be addressed: 1. Pipe diameter issue: Under normal vacuum conditions, the pipelines used for transporting dechlorinated brackish water are quite large; for a caustic soda production facility with a capacity of 150,000 tons, a DN200 pipe is required. The overflow pipe that needs to be added must be at least this large as well. Moreover, due to the effect of gravity alone, the flow velocity is nearly half that of pumping, so the pipe diameter would need to be increased by almost 1.5 times. One can imagine what kind of engineering challenge this represents! 2. Liquid seal issue: Determine the liquid seal height based on the operating conditions of the dechlorination tower. It is necessary to ensure that there is no leakage during normal operation; otherwise, problems will arise. The pressure in the chlorine system will rise immediately, and if this is not detected and addressed in time, the plant will have to be shut down. Additionally, if the dechlorination tower overflows, the issue of gas-liquid entrainment must also be addressed, otherwise flow will be impaired. This post was last edited by wlntjs on 2008-1-12 13:27]
:Handshake. Thank you so much for your guidance; I’ve learned a great deal from it! :) I posed this question, hoping to avoid embarrassing you experts: loveliness: Hehe~!