News (a recent accident at a factory)
Thread Content
At a certain electrochemical company, an instrument failure occurred in the hydrogen vent valve (pneumatic valve) prior to hydrogen synthesis. When the dispatch team ordered maintenance of the instruments, the technician casually opened the valve during the repair work. As a result, large amounts of hydrogen were released; the hydrogen chloride synthesis furnace was immediately filled with large quantities of chlorine. This chlorine was sent to the PVC plant as if it were hydrogen chloride, and it reacted directly with acetylene, causing a violent explosion................
It’s pretty scary, huh. Be careful
Dangerous work, not following the rules! @
This is a serious issue; it represents a flaw in production management. Maintaining such a hydrogen vent valve is carried out during the production process; it is estimated that the valve did not close properly, which is why maintenance was requested by the dispatch team. It is estimated that this valve is a air-operated valve; it opens completely when the instrumentation technician shuts off the gas, which leads to this fault. Perhaps the mechanic just wanted to test whether the valve moved smoothly. Putting aside the technical issues for now, such online maintenance carries extremely high risks. The impact on production cannot be assessed in advance. We once had another instrument technician performing maintenance online; a small screwdriver slipped across the circuit board, causing the turbine to shut down abruptly, which led to the shutdown of the entire plant. Therefore, maintenance work on instruments should be carried out offline as much as possible. First, a maintenance work order must be filled out, with approvals and signatures at each level; emergency preparations must be made, backup facilities activated or affected pathways blocked, before maintenance can proceed. In this example, for instance, if there is a manual shut-off valve before the vent valve, that manual valve can be closed, allowing for easy maintenance. Even if the synthesis furnace shuts down during maintenance, it is possible to easily open the manual valve to release the hydrogen; it isn’t even necessary to do so, as there are other synthesis furnaces operating. Therefore, this fault is a management issue, not a technical one. It should serve as a wake-up call and a source of reflection for peers.
There are problems with management, and the design is also unreasonable
When maintaining chemical instruments, it is generally necessary for the chemical process unit that requires maintenance to issue an operation ticket, while the instrument maintenance team must outline the relevant measures to be taken during the maintenance. The dispatch department should be informed before the maintenance begins; instructions are issued through the operation ticket rather than directly by the dispatch department. In the case of hydrogen-related maintenance, the level of authorization for the operation ticket must rise to that of the safety management department, the production management department, and the instrument management department, with all three parties signing off on it. I believe that as long as proper attention is given to these matters, there should be no problems!
Giving illegal instructions and performing illegal operations； Managing major vulnerabilities can be deadly!
The consequences are quite serious indeed; it’s terrible! !
Violations in the work carried out by the instrument technician. However, the synthesis furnace should be equipped with a hydrogen/chlorine ratio interlock; if such an interlock were in place, accidents of this kind would not occur. Safety chains in this industry are very important.
This situation is due, on the one hand, to the carelessness of the instrument technicians, and on the other hand, to the lack of attention and careful consideration in dispatching work, with safety being ignored. In the chemical industry, even the slightest carelessness can lead to serious accidents.