Continuous differential-pressure steam sterilization system and method for a powder

A continuous differential-pressure steam sterilization system for a powder, comprising:

• a superheated steam generating device, wherein the superheated steam generating device comprises a steam generator and a steam superheater sequentially communicated with each other;
• a steam pressure and flow rate control device, wherein the steam pressure and flow rate control device comprises a pressure reducing and stabilizing mechanism, an automatic control valve, and a flow meter;
• superheated steam generated by the superheated steam generating device flows through the pressure reducing and stabilizing mechanism, the automatic control valve, and the flow meter in sequence;
• the automatic control valve is provided with a steam flow threshold;
• and a control system adjusts a valve opening of the automatic control valve according to a value of the flow meter;
• a first spiral closed-air aspirator, wherein an outlet of the first spiral closed-air aspirator and an outlet of the automatic control valve are communicated with an inlet end of a steam-powder mixing pipe;
• a spiral blade and a motor for driving the spiral blade are provided in a housing of the first spiral closed-air aspirator;
• and an outlet of the first spiral closed-air aspirator is provided with a sealing gland;
• and
• a Laval nozzle, wherein an inlet end of the Laval nozzle is communicated with an outlet end of the steam-powder mixing pipe;
• the powder output from the Laval nozzle is initially cooled by sterile air blown out by a sterile cooling mechanism;
• and after the initial cooling, the powder flows through a primary gas-solid separation system and a secondary gas-solid separation system in sequence;
• wherein steam separated by the primary gas-solid separation system is heated by a steam heater, and then enters a heating pipe of the steam-powder mixing pipe to realize temperature compensation;
• and the heating pipe of the steam-powder mixing pipe wraps the steam-powder mixing pipe;
• the superheated steam generating device and the steam pressure and flow rate control device are controlled such that the generated superheated steam is at 180-210° C. and under 0.2-0.6 Mpa;
• the steam flow threshold is set as 20-30 m/s;
• the steam-powder mixing pipe is 150-300 cm long, and the powder and the superheated steam are controlled to pass through the steam-powder mixing pipe within 0.05-0.15 s;
• and an instantaneous differential pressure of the Laval nozzle is 0.15-0.5 Mpa;
• a first centrifugal chamber and a plurality of second centrifugal chambers are provided in each of the primary gas-solid separation system and the secondary gas-solid separation system;
• the first centrifugal chamber is provided at a center of a cavity body of the separation system, and the second centrifugal chambers are arranged at a side wall of the cavity body and surround the first centrifugal chamber;
• a fluid flows through a first fluid inlet and enters the first central chamber;
• a top fluid outlet of the first centrifugal chamber enters a plurality of branch pipes via a fluid convergence chamber, and enters the second centrifugal chambers through second fluid inlets, respectively;
• and a top fluid outlet of each of the second centrifugal chambers is communicated with the cavity body;
• and
• a distance between the first fluid inlet and a top part of the first centrifugal chamber is ½ of a distance between the first fluid inlet and a bottom part of the first centrifugal chamber;
• and a distance between the second fluid inlet and a top part of the second centrifugal chamber is ½ of a distance between the second fluid inlet and a bottom part of the second centrifugal chamber.