Safety countermeasures for reaction heat, latent heat of reaction and threshold temperature (2)

4.

During the reaction or post-processing operation, the accumulation of latent heat of reaction caused by too low temperature is a low-level mistake that some R&D personnel often make, and the flushing, burning and explosion accidents caused by this are very common

Case 1

Due to the relocation of the laboratory, a certain R&D team processed 8 dissatisfied bottles of waste borane dimethyl sulfide solution

Figure 24-12 Screenshot of the accident video

Figure 24-13 The situation of the fume hood and ceiling after the explosion

Reason analysis: eager for success, violation of operating procedures, causing the hydrogen concentration in the fume hood and the technical interlayer to reach the explosive limit and cause an explosion

Lesson: The forced cooling concealed the true face of the violent reaction and caused the accumulation of latent heat of reaction

Do not pour too much borane dimethyl sulfide solution together in the same barrel for processing.

Case 2

A R&D personnel performs an iron powder reduction reaction;

Add 1kg substrate 1 and 2.

Figure 24-14 The scene after the spray material exploded

Analysis of the cause: a large amount of material is fed before the reaction is initiated, which leads to the accumulation of latent heat of the reaction.

Lesson: The acetic acid reduction reaction of iron powder should be ensured to start, and after the reaction is stable, you can continue to add iron powder, stir while adding, and remove the generated reaction heat through a cold bath

Related Links: Safety Countermeasures for Heat of Reaction, Latent Heat of Reaction and Threshold Temperature (1)