How is tank transfer of liquid chlorine tanks generally carried out?
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This post was last edited by sunjl1981 on 2013-1-6 at 23:32. When a liquid chlorine storage tank leaks, an emergency transfer of the liquid is required – does this involve opening the upper inlet valve for liquid chlorine and then using nitrogen pressure? If that’s the case, wouldn’t pressurizing the leaking tank accelerate the leakage of liquid chlorine even more? # ， ， &
Generally, the liquid-phase connection valve at the bottom of the tank and the gas-phase connection valve at the top of the tank are opened to perform chlorine backflow; the method of using nitrogen pressure is rarely employed.
1) First, open the exhaust valve of the receiving equipment to release pressure, then open the inlet valve of the receiving equipment. 2) Open the outlet valve of the liquid chlorine storage tank, the chlorine inlet valve, and the chlorine outlet valve of the pressure evaporation reactor. 3) Open the hot water valve of the evaporator jacket to vaporize liquid chlorine into gaseous chlorine, thereby generating pressure to compress the material. 4) Once completed, close the hot water valve of the evaporator jacket and the chlorine outlet valve, close the outlet valve of the liquid chlorine storage tank, and at the same time close the feed valve and exhaust valve of the receiving equipment.
Now, most manufacturers no longer use carburetors for filling; instead, they employ submersible pumps or shielded pumps. 1. Reduce the accumulation of nitrogen trichloride ； 2. Improve the production efficiency of liquid chlorine and reduce its losses ； 3. Ensure safety. Therefore, our current plan is to use a submersible pump for tank transfer.
What you’re referring to is actually the automatic transfer of liquid between containers based on the difference in liquid levels, right? If you pour the liquid using this method, at most only 50% of the chlorine can be poured out. When the liquid levels in the two tanks are the same, it is no longer possible to transfer fluid between them by gravity. ? ?
There are also problems with transferring tanks using submersible pumps. Because the flow rate of submersible pumps used for packaging is usually relatively low, around 10 cubic meters per hour. Even if two submersible pumps are used simultaneously to transfer the liquid, it takes 4 hours to empty an 80-cubic-meter tank. It’s too slow
Our plan is as follows: First, transfer the material to a backup tank (under equal pressure), and once the pressure is balanced, use an submersible pump to transfer the material. If such a situation does arise, they can be carried out simultaneously.
Don’t you consider using nitrogen pressure? Is it because they are afraid of worsening the leakage? Or are there other reasons to consider?
We use pumps to transfer the liquid. Once the storage tank leaks, we close the sealed doors of the facility; then we start the liquid chlorine pump to transfer the liquid. At the same time, we activate the fans in the facility to draw out the leaked gaseous chlorine and send it to the waste gas treatment system
We also rely on our own pressure to drive the flow in reverse; the speed is slow, and as mentioned above, we are powerless once the pressure is balanced. It was considered to dig a trench next to the storage tank; in the event of a leak, fluid would flow back into this trench, and the bottom valve could be opened to drain the liquid there, after which an alkaline solution could be introduced into the trench to absorb it. But it was not carried out.
An emergency plan for the liquid chlorine storage area, as a major hazard source, requires the presence of backup tanks in case of an accident. The backup tank can be positioned at a lower level than the tank in use; by utilizing the pressure difference, the tank can be inverted, and during this process the pressure relief valve of the backup tank can be connected to the accident chlorine treatment device, ensuring that its pressure remains always lower than that of the accident tank. When using a submersible pump to transfer liquid into the tank, the speed must be controlled; it cannot be too fast. (The explosion at the Chongqing Tianyuan storage tank was caused by the rapid transfer of liquid using a submersible pump, which led to the decomposition and explosion of NCl3)
There should be spare tanks that are under negative pressure; when the operating tank leaks, the material valve at the bottom of the spare tank is opened, and the liquid chlorine is quickly pushed through
This is how it works: there are a total of ten liquid chlorine storage tanks, of which only 9 may be used during normal operations; one tank serves as an emergency reserve. 1. Perform backflow when a minor leak occurs. During backflow, take appropriate action based on the situation; in emergencies, a filling pump can be used. 2. In the event of a major accident, while performing backflow control, activate alkali spraying and fans to trigger early warnings as part of the emergency response plan.