Is nitrogen protection required in the process of polymerizing formaldehyde to produce polyformaldehyde?
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Dear teachers on this forum, I was wondering if there are any experts who have extensive experience with the polyoxymethylene manufacturing process? Polyformaldehyde is produced by the polymerization of formaldehyde through spray granulation. Information available online indicates that polyformaldehyde poses a risk of dust explosions; the processes described in such materials involve the use of nitrogen for protection. However, the project owner insists on using a process that does not rely on nitrogen protection, and the manufacturers of the spray granulation equipment also recommend a process without nitrogen protection, with no nitrogen connections available on the equipment. From a safety perspective, though, is it necessary to use nitrogen protection in this process? I hope a teacher who knows this area can provide some clear guidance. Thank you!
If nitrogen protection cannot be used, it is recommended to employ a supplementary steam method to reduce the score
The drying process in the production of polyformaldehyde requires the use of nitrogen gas; its primary function is as a drying gas rather than a shielding gas. Nitrogen is used to prevent dust explosions.
3# jingsan So that means nitrogen should be used in the manufacturing process to prevent dust explosions? Dry with nitrogen? I’m not quite sure
Air flow drying requires high-temperature drying gas as the drying medium; the heated gas flows rapidly through the pipes, and once the wet material enters these pipes, it is carried toward the pipe outlet by the fast-flowing air； During this process, water vapor is evaporated due to the effects of convective heat and mass transfer. Since the material is dispersed by high-speed airflow upon entering the pipeline, resulting in thorough mixing, a cyclone separator is typically used at the pipeline outlet to separate the gas and solid phases. The gas used for air-drying is usually air, but inert gases should be employed in drying processes where there is a risk of dust explosions.
Adding a reducing partial pressure is necessary; otherwise, high-concentration formaldehyde gas tends to polymerize on its own
Nitrogen protection is necessary, and an online analysis and control system for oxygen content must be established; if drying is done with air, there is a risk of dust explosions
Nitrogen protection is required because polyoxymethylene is in powder form and a dust explosion could occur
It seems that using nitrogen protection for formaldehyde polymerization is essential. When carrying out this installation, this part was already added. It’s just that the manufacturer has always been reluctant to install this equipment, which is why the installation assessment hasn’t been completed yet.
Nitrogen protection should be added to prevent explosions; if air enters, side reactions intensify, resulting in the formation of other oligomers and thus a lower purity of the product.