The safety devices of homogeneous reactors (commonly used for homogeneous reactions in chemical, pharmaceutical, materials and other fields, such as solution polymerization, catalytic reactions, etc.) are designed around the four core risk points of "pressure control, temperature control, material leakage prevention, and emergency protection", ensuring that the pressure, temperature, and material state are controllable during the reaction process, avoiding safety accidents such as overpressure explosion, high-temperature runaway, toxic/flammable material leakage, etc. The specific safety devices and functions are as follows:
1、 Pressure control and explosion-proof safety device (core protection, avoiding overpressure explosion)
1. Safety valve (basic device)
Function: When the pressure of the reaction system exceeds the preset safe value (usually 1.1 times the design pressure of the reactor), it automatically opens to release pressure, reduces the pressure to the safe range, and then closes to prevent overpressure rupture of the reactor;
Key requirements:
The material needs to be compatible with the reaction medium (such as corrosion-resistant materials for acid-base reactions, explosion-proof materials for flammable systems);
Regularly verify (at least once a year) to ensure accurate opening pressure and avoid jamming or leakage;
The discharge outlet needs to be connected to a conduit to guide the pressure relief material to a safe area (such as a flare system or exhaust treatment device), avoiding direct discharge of toxic/flammable materials.
2. Explosive disc (emergency pressure relief device, used in conjunction with safety valve)
Function: For scenarios where the reaction may rapidly increase pressure (such as uncontrolled polymerization reactions or intense heat release), the rupture disk will instantly rupture when the pressure reaches the set value, achieving rapid pressure relief (much faster than the safety valve) and avoiding reactor overpressure explosion in a short period of time;
Key requirements:
The blasting pressure should be lower than the design pressure of the reactor and higher than the opening pressure of the safety valve;
As a disposable device, it needs to be replaced after rupture and equipped with a "bursting disc rupture alarm" function (such as a pressure sudden change sensor) to promptly alert the operator;
The material needs to withstand the corrosion and temperature of the reaction medium (such as using metal materials for high-temperature reactions and PTFE coated rupture discs for corrosive media).
3. Pressure sensors and alarm interlocking devices
Function: Real time monitoring of the pressure inside the reaction vessel, triggering an audible and visual alarm when the pressure approaches a safe threshold (such as 90% of the design pressure); If the pressure continues to rise, the automatic interlock will close the feed valve and heating device, and at the same time activate the pressure relief valve or emergency cooling system to prevent the pressure from continuing to rise from the source;
Application scenario: Suitable for homogeneous reactors with high degree of automation, especially suitable for exothermic reactions and high-pressure reactions (such as hydrogenation reactions).
2、 Temperature control and anti runaway safety device (to avoid accumulation of reaction heat)
1. Temperature sensor and cooling interlock system
Function: Real time monitoring of reaction system temperature through built-in temperature probe. When the temperature exceeds the set upper limit (such as process requirement temperature+10 ℃), the cooling system (such as jacket cooling water, coil cooling) will automatically start and the heating device will be turned off; If the temperature continues to rise, further interlock to stop the feed and prevent the reaction from losing control (such as "runaway");
Key requirement: The temperature sensor should be inserted into the core area of the reaction system to avoid misjudgment caused by local temperature detection deviation; The cooling system needs to ensure sufficient cooling power and backup cooling circuits (such as emergency cooling water tanks).
2. Emergency cooling device (emergency measures for uncontrolled reactions)
Function: When the conventional cooling system fails or the reaction temperature rises sharply, activate the emergency cooling device to quickly reduce the temperature of the reaction system;
Common types:
Emergency cooling water for jacket/coil (independent of conventional cooling system, driven by backup pump);
Inert gas cooling (such as introducing low-temperature nitrogen while taking away the heat of reaction);
Inject cooling medium into the kettle (such as injecting low-temperature solvents for low boiling point reaction systems, but avoid affecting reaction safety).
3. Heat exchanger anti blocking/anti leakage device
Function: The jacket, coil and other heat exchange components of the homogeneous reactor need to be equipped with filters (to prevent material crystallization from blocking the pipeline) and leak detection sensors (such as monitoring whether cooling water is mixed with the reaction medium);
Consequence avoidance: Avoid temperature control caused by a decrease in heat exchange efficiency, or safety risks caused by contamination of the reaction medium by cooling water (such as explosions caused by contact between flammable media and water).
3、 Material leakage prevention and protective safety devices (to prevent the spread of toxic/flammable materials)
1. Sealing system (shaft seal/kettle cover seal)
Function: To prevent leakage of reaction medium from the reactor shaft seal (stirring shaft) or kettle cover connection, especially for toxic, flammable, and corrosive materials;
Common types:
Mechanical seal (suitable for high-pressure and high-speed mixing scenarios, with better sealing performance than packing seal);
Magnetic seal (no shaft penetration, completely sealed, suitable for high-risk media reactions, such as highly toxic and corrosive materials);
Safety requirements: Equipped with a sealed leak detection sensor (such as monitoring whether there is material leakage at the sealed area), promptly alarm and shut down in case of leakage.
2. Cofferdam and collection tank (to prevent leakage and diffusion)
Function: Set up a cofferdam (usually ≥ 15cm in height) and collection tank around the reactor. When there is a leakage in the reactor (such as kettle rupture or pipeline leakage), the materials will be confined within the cofferdam to avoid spreading to the workshop and causing fires, poisoning, or environmental pollution;
Applicable scenarios: Homogeneous reactors that handle large quantities of flammable, toxic, or corrosive materials (such as industrial grade production facilities).
3. Inert gas protection system (anti-oxidation/explosion-proof)
Function: For reaction systems that are flammable, explosive, or easily oxidized (such as hydrogenation reactions and polymerization reactions), inert gases (such as nitrogen and argon) are introduced to replace the air (oxygen) inside the reactor, maintaining an inert atmosphere inside the kettle and preventing materials from coming into contact with oxygen and causing combustion or explosion;
Key configuration: Equipped with an oxygen content sensor to monitor the oxygen content in the kettle in real time. When the oxygen content exceeds the safety threshold (usually ≤ 1%), it automatically replenishes inert gas to ensure protection effectiveness.