The invention discloses a device and a method for preparing 1,3,5-
trioxane continuously from concentrated
formaldehyde as a
raw material. The device comprises a reaction and concentration
system, a
crystallization system and a refining
system. The reaction and concentration system is mainly used for preparing 1,3,5-
trioxane from concentrated
formaldehyde as the
raw material through a reaction under the action of a catalyst and concentrating 1,3,5-
trioxane into a 1,3,5-trioxane solution with the concentration of 63% through a concentrating
tower; the
crystallization system is mainly used for concentrating the 1,3,5-trioxane solution with the concentration of 63% into a 1,3,5-trioxane solution with the concentration of 93% through
crystallization; the refining system is mainly used for refining the 1,3,5-trioxane solution with the concentration of 93% into a 1,3,5-trioxane solution with the concentration of 99.9%, and the 1,3,5-trioxane solution serving as an
intermediate product is conveyed to other devices for use. Compared with a 1,3,5-trioxane preparing
route adopting extraction, the device and the method have the advantages that the flow and the operation are simple,
energy consumption is low, environmental
pollution caused by
benzene is reduced effectively, and the device and the method are quite suitable for large-scale industrial production.