Process and device for continuously producing isatoic anhydride

The invention discloses a process and a device for continuously producing isatoic anhydride by taking phthalic anhydride as a raw material. The process for continuously producing the isatoic anhydrideby taking the phthalic anhydride as the raw material comprises the following steps: (1) respectively feeding a phthalic anhydride aqueous solution and an ammonia aqueous solution into a pipeline reactor and a gettering filter according to a certain flow rate, then feeding the mixture and a sodium hydroxide solution into a secondary pipeline reactor for mixing reaction, and then feeding the mixture into a temporary storage tank; (2) separating excessive ammonia gas and solution from the solution in the temporary storage tank through a polypropylene hollow fiber film device, enabling the ammonia gas to enter an ammonia gas storage tank through a water ring vacuum pump, a film press and a drying absorption tower, and enabling the solution to enter the temporary storage tank; (3) respectivelyfeeding the temporary sto