Uses of compressed air issues in dechlorination towers

It is used during air purging, and can also be used for replacement before entering the dechlorination tower for maintenance. Generally, manufacturers do not use air blowing as a method, because the waste chlorine gas produced requires the creation of sodium hypochlorite, which is not cost-effective. Therefore, air-blowing dechlorination is merely a backup to vacuum dechlorination.

1. For parking, maintenance, and replacement! :Lol, otherwise the chlorine inside won’t be replaced thoroughly! When maintaining the equipment, the clamps at both the top and bottom of the dechlorination tower are left open, which makes the replacement process easy and effective. 2. For the airtightness test, pressurize with air to detect leaks starting from the modification point. 3. In special cases, for example, when replacing chlorine pipes, it is convenient to blow air into the chlorine pipes from here to replace the gas. 4. As for air-assisted dechlorination, I think its effectiveness is basically......... There is no air distributor inside the dechlorination tower; once the air emerges, it goes directly into the waste chlorine or chlorine gas system. Moreover, this increases the pressures of both the gas and liquid phases inside the dechlorination tower, thereby restricting the precipitation of chlorine gas. This constitutes a limitation on the design and proper operation of the vacuum dechlorination device itself. 5. If there are any mistakes, I hope everyone can give me some guidance. . . . This post was last edited by 181128425 on 2009-3-7 09:28]

The dechlorination in the Asahi Kasei system can be switched to air purge； System dechlorination by air blowing in the chlorine plant does not seem to be designed. The techniques used by different manufacturers may vary slightly, but air blowing is already a mature technique, and its effectiveness is no worse than that of vacuum dechlorination. Since the part number mentioned by the original poster happens to be from Asahi Kasei, this conclusion was drawn; at the same time, I would like to remind everyone to indicate as much as possible which company’s system they are using when posting.

Air blowing is a mature technology, and its effectiveness is no worse than that of vacuum dechlorination; air blowing is a mature technology, and its effectiveness is no worse than that of vacuum dechlorination. I wholeheartedly agree with this view! What is the design load of your exhaust gas system? (This includes the continuous high-temperature operation time of the column, the duration during which the exhaust gas system can operate at its maximum load, the power required for the airflow, as well as the flow rate of the gases being transported, etc.) How is the issue of air deviation inside the column addressed? What to do when the negative pressure around -67 KPa is lost? What role does the vacuum pump play in such situations? And what to do if all the pipes in the exhaust gas system are under positive pressure? I’m sorry for the questions... Please forgive me. This post was last edited by yzhms on 2009-3-7 at 12:26

Hehe, we use steam ejectors, and the tower is made of titanium; there is packing inside the tower, so the possibility of deviation in flow is very low. An air flow rate of 300–600 m3/h is not considered high for an emergency chlorine treatment system; the chlorine flow rate at the beginning of operation is roughly the same amount. Therefore, there is no need to consider the size of the emergency chlorine handling system separately – if necessary, simply add another fan. (Generally, air blowing is not used during startup and shutdown; it is a backup method used only when there is a failure in vacuum dechlorination or when the steam pressure is low…) In chlor-alkali plants I’ve seen, vacuum pumps generate negative pressure, and the towers are made of titanium; however, I’m not sure whether there are packing materials inside, but it seems that no air blowing method is used. Since one vacuum pump is in operation while another is on standby, there are generally no problems. This is different from steam injection; if the steam pressure is insufficient and air cannot be used for removal, the system has to be shut down... which is not worth it. There is also a type of hydraulic jet pump that uses chlorine water or brackish water for spraying, with a circulation pump providing the power; it also yields good results. Regarding vacuum dechlorination, there are essentially three methods: vacuum pumps, steam injection, and hydraulic injection. All of these processes are mature, but it is not clear which one has the lowest overall energy consumption. I hope someone up there will start a dedicated thread for discussion... Raleigh is being wordy; I’m not sure if those who answered are satisfied Last edited by sister on 2009-3-7 12:34]

We are from Asahi Kasei; the vacuum pumps are operated in one while another is on standby. I believe they are mainly used for purging chlorine pipelines in case of accidents and for replacing the gas inside the tower during maintenance, rather than for dechlorination using the purge method

Our company uses Asahi Kasei’s equipment and technology; the vacuum pumps are operated in a one-active-one-redundant configuration. Logically, it’s unlikely that both vacuum pumps will fail at the same time. However, the air pipeline exists as a backup solution in case both pumps cannot operate simultaneously. It’s not possible to shut down the entire production line just because vacuum dechlorination is not functioning properly! Using air for expulsion is a last-resort measure, as the resulting waste chlorine gas would need to be converted into sodium hypochlorite, which is not very economical. Therefore, air blowing dechlorination is merely a backup to vacuum dechlorination, the second alternative solution. This post was last edited by limingshuguang on 2009-3-9 16:38]

·The compressed air in the dechlorination tower is used for blowing purposes. (I discussed this issue with Asahi Kasei’s technician Anshi.) When there is a problem with the vacuum pump, it is not possible to stop the system immediately; therefore, the chlorine in the system is released in order to continue operating. The quality of this chlorine is poor, so at such times the chlorine is directed to the waste gas treatment system. Generally, a water seal is installed next to D-280 (the cathode discharge tank) to reduce the negative pressure.