How is the fire hazard classified in the sodium bicarbonate production workshop of soda ash manufacturing?
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Dear experts, the raw materials used in the sodium bicarbonate workshop during soda ash production include ammoniated brine and ammonia mother liquor I and II (which contain free ammonia at a concentration of approximately 77 tt, equivalent to roughly 5% by mass). According to the requirements of the Code for Fire Protection Design of Buildings, ammonia falls under Class B substances. However, currently, various design institutes design the heavy soda ash workshops or ammonium chloride workshops under the ammonia-soda and combined soda processes as Class D and E facilities in terms of fire hazard; their fire protection designs have also all been approved. At present, in China, the equipment motors used in the heavy soda ash workshops and ammonium chloride workshops of various soda ash plants are all ordinary motors; none of them are designed as explosion-proof motors. Moreover, it seems that no safety incidents such as fires or explosions caused by non-explosion-proof motors have occurred at any soda ash plants. I’m a bit confused about how to classify things in the design I hope you all can offer some guidance.
What my friend referred to was the sodium bicarbonate production workshop within the combined alkali process system. In theory, its level of hazard might be slightly higher than that of similar workshops in the ammonia-soda process. However, since there are no particularly hazardous materials involved, it’s quite normal to use ordinary motors and switches instead of explosion-proof ones.
This is where design comes into play. Some designers are concerned about safety issues, so they opt for higher-spec designs. In our calcination workshop, we need to install a ventilation fan; however, the designers recommended using a fan with an explosion-proof motor.
I believe this is done to improve safety levels and reduce the occurrence of explosion accidents; however, in reality, it doesn’t have much practical significance.
Addressing this issue is very necessary. Currently, some parts of the ammonia-soda process utilize shifted gas for soda ash production; this issue deserves greater attention ； Shifted gas is a flammable and explosive combustible gas, thus requiring higher safety standards. It is recommended to raise the respective design levels of the AII and the cleaning AII pumps. At the same time, the carbonization post should also be included in the management of major hazard sources.