The reaction vessel is cooled with water; what safety measures are in place to prevent water-sensitive materials from coming into contact with water?

When cooling water must be used in the jacket of a reaction vessel, the main safety measures to prevent water-sensitive materials (such as thionyl chloride, phosphorus trioxide, etc.) from coming into accidental contact with water are: 1. Strict quality control of the vessel body – use jacketed reaction vessels that are corrosion-resistant, high-strength, and have either no welds or reliable welds. - Regularly check the integrity of the reactor jacket (such as pressure and leakage). 2. Control of pressure difference inside and outside the reactor – Keep the pressure in the jacket always lower than the pressure of the material inside the reactor. Ensure that in the event of a minor leak, it is the material that leaks into the cooling water system, rather than water from the jacket entering the reactor, thereby preventing accidental escalation of risks. 3. Monitoring and alarm for the cooling water system – Flow, pressure, and temperature monitoring sensors as well as online alarm devices are installed at the inlet and outlet of the jacket. If the flow rate of the jacket cooling water decreases abnormally, or if there are changes in water quality (changes in pH or conductivity, especially the detection of components from leaked materials), an alarm should be triggered immediately and emergency response procedures initiated. 4. Install an intermediate isolation heat exchange medium (recommended measure) – Add a safe intermediate heat exchange system between the reactor and the water cooling system, such as using safe heat exchange oils (mineral oils with high flash points, organic thermal conductants, etc.). Through indirect heat exchange, the possibility of water-sensitive materials coming into direct contact with water is completely avoided. 5. Emergency shutdown and evacuation measures – If it is not appropriate to use an indirect heat transfer medium, emergency shut-off valves should be installed on the inlet and outlet pipelines of the jacket. If a leak is suspected, the water supply to the jacket can be stopped immediately and the jacket water drained to prevent further water from the jacket from entering the tank. 6. Backflow prevention design – Reliable check valves or non-return valves are installed at the inlet of the jacket cooling water system to prevent cooling water from flowing back into the reactor in case of an accident. 7. Regular maintenance and inspection – Establish a strict plan for equipment inspection and maintenance, and carry out regular maintenance and checks on the reactor jacket and associated equipment to identify and eliminate potential hazards promptly. According to the newly issued AQ 3062-2025 \"Safety Management Standards for Fine Chemical Enterprises,\" chlorination reactions involving water-sensitive, exothermic reactants should, as much as possible, avoid being cooled using aqueous media. If water must be used, the aforementioned technical measures (especially physical isolation and strict monitoring and control) must be implemented to ensure safety. .

We use an anhydrous ammonia system, with one tank and one pump, which is used after heating or cooling.

A single device can be connected directly to the TCU system, or to a heat transfer oil system

Another approach is: if the reactor only needs to be cooled down and not heated (in cases where the reaction takes place at a low temperature and is exothermic), a reactor without a jacket can be used, with cooling water flowing through external coiling tubes.

It needs to be cooled as well as heated. Could you please provide us with your modification plan so we can take it into consideration? Thank you

Afraid of water; coolants such as ethylene glycol can be used as heat transfer media